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Sample records for ion collider rhic

  1. High-energy high-luminosity electron-ion collider eRHIC

    E-Print Network [OSTI]

    Litvinenko, Vladimir N; Belomestnykh, Sergei; Ben-Zvi, Ilan; Blaskiewicz, Michael M; Calaga, Rama; Chang, Xiangyun; Fedotov, Alexei; Gassner, David; Hammons, Lee; Hahn, Harald; Hao, Yue; He, Ping; Jackson, William; Jain, Animesh; Johnson, Elliott C; Kayran, Dmitry; Kewisch, Jrg; Luo, Yun; Mahler, George; McIntyre, Gary; Meng, Wuzheng; Minty, Michiko; Parker, Brett; Pikin, Alexander; Pozdeyev, Eduard; Ptitsyn, Vadim; Rao, Triveni; Roser, Thomas; Skaritka, John; Sheehy, Brian; Tepikian, Steven; Than, Yatming; Trbojevic, Dejan; Tsentalovich, Evgeni; Tsoupas, Nicholaos; Tuozzolo, Joseph; Wang, Gang; Webb, Stephen; Wu, Qiong; Xu, Wencan; Zelenski, Anatoly

    2011-01-01

    In this paper, we describe a future electron-ion collider (EIC), based on the existing Relativistic Heavy Ion Collider (RHIC) hadron facility, with two intersecting superconducting rings, each 3.8 km in circumference. A new ERL accelerator, which provide 5-30 GeV electron beam, will ensure 10^33 to 10^34 cm^-2 s^-1 level luminosity.

  2. eRHIC Design Study: An Electron-Ion Collider at BNL

    E-Print Network [OSTI]

    E. C. Aschenauer; M. D. Baker; A. Bazilevsky; K. Boyle; S. Belomestnykh; I. Ben-Zvi; S. Brooks; C. Brutus; T. Burton; S. Fazio; A. Fedotov; D. Gassner; Y. Hao; Y. Jing; D. Kayran; A. Kiselev; M. A. C. Lamont; J. -H. Lee; V. N. Litvinenko; C. Liu; T. Ludlam; G. Mahler; G. McIntyre; W. Meng; F. Meot; T. Miller; M. Minty; B. Parker; R. Petti; I. Pinayev; V. Ptitsyn; T. Roser; M. Stratmann; E. Sichtermann; J. Skaritka; O. Tchoubar; P. Thieberger; T. Toll; D. Trbojevic; N. Tsoupas; J. Tuozzolo; T. Ullrich; E. Wang; G. Wang; Q. Wu; W. Xu; L. Zheng

    2014-12-18

    This document presents BNL's plan for an electron-ion collider, eRHIC, a major new research tool that builds on the existing RHIC facility to advance the long-term vision for Nuclear Physics to discover and understand the emergent phenomena of Quantum Chromodynamics (QCD), the fundamental theory of the strong interaction that binds the atomic nucleus. We describe the scientific requirements for such a facility, following up on the community-wide 2012 white paper, 'Electron-Ion Collider: the Next QCD Frontier', and present a design concept that incorporates new, innovative accelerator techniques to provide a cost-effective upgrade of RHIC with polarized electron beams colliding with the full array of RHIC hadron beams. The new facility will deliver electron-nucleon luminosity of 10^33-10^34 cm-1sec-1 for collisions of 15.9 GeV polarized electrons on either 250 GeV polarized protons or 100 GeV/u heavy ion beams. The facility will also be capable of providing an electron beam energy of 21.2 GeV, at reduced luminosity. We discuss the on-going R&D effort to realize the project, and present key detector requirements and design ideas for an experimental program capable of making the 'golden measurements' called for in the EIC White Paper.

  3. eRHIC Design Study: An Electron-Ion Collider at BNL

    E-Print Network [OSTI]

    Aschenauer, E C; Bazilevsky, A; Boyle, K; Belomestnykh, S; Ben-Zvi, I; Brooks, S; Brutus, C; Burton, T; Fazio, S; Fedotov, A; Gassner, D; Hao, Y; Jing, Y; Kayran, D; Kiselev, A; Lamont, M A C; Lee, J -H; Litvinenko, V N; Liu, C; Ludlam, T; Mahler, G; McIntyre, G; Meng, W; Meot, F; Miller, T; Minty, M; Parker, B; Pinayev, I; Ptitsyn, V; Roser, T; Stratmann, M; Sichtermann, E; Skaritka, J; Tchoubar, O; Thieberger, P; Toll, T; Trbojevic, D; Tsoupas, N; Tuozzolo, J; Ullrich, T; Wang, E; Wang, G; Wu, Q; Xu, W; Zheng, L

    2014-01-01

    This document presents BNL's plan for an electron-ion collider, eRHIC, a major new research tool that builds on the existing RHIC facility to advance the long-term vision for Nuclear Physics to discover and understand the emergent phenomena of Quantum Chromodynamics (QCD), the fundamental theory of the strong interaction that binds the atomic nucleus. We describe the scientific requirements for such a facility, following up on the community wide 2012 white paper, "Electron-Ion Collider: the Next QCD Frontier", and present a design concept that incorporates new, innovative accelerator techniques to provide a cost-effective upgrade of RHIC with polarized electron beams colliding with the full array of RHIC hadron beams. The new facility will deliver electron-nucleon luminosity of $\\sim10^{33} cm^{-2}sec^{-1}$ for collisions of 15.9 GeV polarized electrons on either 250 GeV polarized protons or 100 GeV/u heavy ion beams. The facility will also be capable of providing an electron beam energy of 21.2 GeV, at reduc...

  4. High-energy high-luminosity electron-ion collider eRHIC

    SciTech Connect (OSTI)

    Litvinenko, V.N.; Ben-Zvi, I.; Hammons, L.; Hao, Y.; Webb, S.; et al

    2011-08-09

    In this paper, we describe a future electron-ion collider (EIC), based on the existing Relativistic Heavy Ion Collider (RHIC) hadron facility, with two intersecting superconducting rings, each 3.8 km in circumference. The replacement cost of the RHIC facility is about two billion US dollars, and the eRHIC will fully take advantage and utilize this investment. We plan adding a polarized 5-30 GeV electron beam to collide with variety of species in the existing RHIC accelerator complex, from polarized protons with a top energy of 325 GeV, to heavy fully-striped ions with energies up to 130 GeV/u. Brookhaven's innovative design, is based on one of the RHIC's hadron rings and a multi-pass energy-recovery linac (ERL). Using the ERL as the electron accelerator assures high luminosity in the 10{sup 33}-10{sup 34} cm{sup -2} sec{sup -1} range, and for the natural staging of eRHIC, with the ERL located inside the RHIC tunnel. The eRHIC will provide electron-hadron collisions in up to three interaction regions. We detail the eRHIC's performance in Section 2. Since first paper on eRHIC paper in 2000, its design underwent several iterations. Initially, the main eRHIC option (the so-called ring-ring, RR, design) was based on an electron ring, with the linac-ring (LR) option as a backup. In 2004, we published the detailed 'eRHIC 0th Order Design Report' including a cost-estimate for the RR design. After detailed studies, we found that an LR eRHIC has about a 10-fold higher luminosity than the RR. Since 2007, the LR, with its natural staging strategy and full transparency for polarized electrons, became the main choice for eRHIC. In 2009, we completed technical studies of the design and dynamics for MeRHIC with 3-pass 4 GeV ERL. We learned much from this evaluation, completed a bottom-up cost estimate for this $350M machine, but then shelved the design. In the same year, we turned again to considering the cost-effective, all-in-tunnel six-pass ERL for our design of the high-luminosity eRHIC. In it, electrons from the polarized pre-injector will be accelerated to their top energy by passing six times through two SRF linacs. After colliding with the hadron beam in up to three detectors, the e-beam will be decelerated by the same linacs and dumped. The six-pass magnetic system with small-gap magnets will be installed from the start. We will stage the electron energy from 5 GeV to 30 GeV stepwise by increasing the lengths of the SRF linacs. We discuss details of eRHIC's layout in Section 3. We considered several IR designs for eRHIC. The latest one, with a 10 mrad crossing angle and {beta}* = 5 cm, takes advantage of newly commissioned Nb{sub 3}Sn quadrupoles. Section 4 details the eRHIC lattice and the IR layout. The current eRHIC design focuses on electron-hadron collisions. If justified by the EIC physics, we will add a 30 GeV polarized positron ring with full energy injection from eRHIC ERL. This addition to the eRHIC facility provide for positron-hadron collisions, but at a significantly lower luminosity than those attainable in the electron-hadron mode. As a novel high-luminosity EIC, eRHIC faces many technical challenges, such as generating 50 mA of polarized electron current. eRHIC also will employ coherent electron cooling (CeC) for the hadron beams. Staff at BNL, JLab, and MIT is pursuing vigorously an R&D program for resolving addressing these obstacles. In collaboration with Jlab, BNL plans experimentally to demonstrate CeC at the RHIC. We discuss the structure and the status of the eRHIC R&D in Section 5.

  5. eRHIC - A precision electron-proton/ion collider facility at Brookhaven National Laboratory

    E-Print Network [OSTI]

    Surrow, B

    2005-01-01

    An electron-proton/ion collider facility (eRHIC) is under consideration at Brookhaven National Laboratory (BNL). Such a new facility will require the design and construction of a new optimized detector profiting from the experience gained from the H1 and ZEUS detectors operated at the HERA collider at DESY. The details of the design will be closely coupled to the design of the interaction region, and thus to the machine development work in general. An overview of the accelerator and detector design concepts will be provided.

  6. eRHIC - A precision electron-proton/ion collider facility at Brookhaven National Laboratory

    E-Print Network [OSTI]

    Bernd Surrow

    2006-02-02

    An electron-proton/ion collider facility (eRHIC) is under consideration at Brookhaven National Laboratory (BNL). Such a new facility will require the design and construction of a new optimized detector profiting from the experience gained from the H1 and ZEUS detectors operated at the HERA collider at DESY. The details of the design will be closely coupled to the design of the interaction region, and thus to the machine development work in general. An overview of the accelerator and detector design concepts will be provided.

  7. Measurements of phi meson production in relativistic heavy-ion collisions at the BNL Relativistic Heavy Ion Collider (RHIC

    E-Print Network [OSTI]

    Abelev, B. I.; Aggarwal, M. M.; Ahammed, Z.; Anderson, B. D.; Arkhipkin, D.; Averichev, G. S.; Bai, Y.; Balewski, J.; Barannikova, O.; Barnby, L. S.; Baudot, J.; Baumgart, S.; Beavis, D. R.; Bellwied, R.; Benedosso, F.; Betts, R. R.; Bhardwaj, S.; Bhasin, A.; Bhati, A. K.; Bichsel, H.; Bielcik, J.; Bielcikova, J.; Biritz, B.; Bland, L. C.; Blyth, S. -L; Bombara, M.; Bonner, B. E.; Botje, M.; Bouchet, J.; Braidot, E.; Brandin, A. V.; Bruna, E.; Bueltmann, S.; Burton, T. P.; Bystersky, M.; Cai, X. Z.; Caines, H.; Sanchez, M. Calderon de la Barca; Callner, J.; Catu, O.; Cebra, D.; Cendejas, R.; Cervantes, M. C.; Chajecki, Z.; Chaloupka, P.; Chattopadhyay, S.; Chen, H. F.; Chen, J. H.; Chen, J. Y.; Cheng, J.; Cherney, M.; Chikanian, A.; Choi, K. E.; Christie, W.; Chung, S. U.; Clarke, R. F.; Codrington, M. J. M.; Coffin, J. P.; Cormier, T. M.; Cosentino, M. R.; Cramer, J. G.; Crawford, H. J.; Das, D.; Dash, S.; Daugherity, M.; De Silva, C.; Dedovich, T. G.; DePhillips, M.; Derevschikov, A. A.; de Souza, R. Derradi; Didenko, L.; Djawotho, P.; Dogra, S. M.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Du, F.; Dunlop, J. C.; Mazumdar, M. R. Dutta; Edwards, W. R.; Efimov, L. G.; Elhalhuli, E.; Elnimr, M.; Emelianov, V.; Engelage, J.; Eppley, G.; Erazmus, B.; Estienne, M.; Eun, L.; Fachini, P.; Fatemi, R.; Fedorisin, J.; Feng, A.; Filip, P.; Finch, E.; Fine, V.; Fisyak, Y.; Gagliardi, Carl A.; Gaillard, L.; Gangadharan, D. R.; Ganti, M. S.; Garcia-Solis, E.; Ghazikhanian, V.; Ghosh, P.; Gorbunov, Y. N.; Gordon, A.; Grebenyuk, O.; Grosnick, D.; Grube, B.; Guertin, S. M.; Guimaraes, K. S. F. F.; Gupta, A.; Gupta, N.; Guryn, W.; Haag, B.; Hallman, T. J.; Hamed, A.; Harris, J. W.; He, W.; Heinz, M.; Heppelmann, S.; Hippolyte, B.; Hirsch, A.; Hoffman, A. M.; Hoffmann, G. W.; Hofman, D. J.; Hollis, R. S.; Huang, H. Z.; Humanic, T. J.; Igo, G.; Iordanova, A.; Jacobs, P.; Jacobs, W. W.; Jakl, P.; Jin, F.; Jones, P. G.; Joseph, J.; Judd, E. G.; Kabana, S.; Kajimoto, K.; Kang, K.; Kapitan, J.; Kaplan, M.; Keane, D.; Kechechyan, A.; Kettler, D.; Khodyrev, V. Yu; Kiryluk, J.; Kisiel, A.; Klein, S. R.; Knospe, A. G.; Kocoloski, A.; Koetke, D. D.; Kopytine, M.; Kotchenda, L.; Kouchpil, V.; Kravtsov, P.; Kravtsov, V. I.; Krueger, K.; Krus, M.; Kuhn, C.; Kumar, L.; Kurnadi, P.; Lamont, M. A. C.; Landgraf, J. M.; LaPointe, S.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, C. -H; LeVine, M. J.; Li, C.; Li, Y.; Lin, G.; Lin, X.; Lindenbaum, S. J.; Lisa, M. A.; Liu, F.; Liu, H.; Liu, J.; Liu, L.; Ljubicic, T.; Llope, W. J.; Longacre, R. S.; Love, W. A.; Lu, Y.; Ludlam, T.; Lynn, D.; Ma, G. L.; Ma, J. G.; Ma, Y. G.; Mahapatra, D. P.; Majka, R.; Mall, M. I.; Mangotra, L. K.; Manweiler, R.; Margetis, S.; Markert, C.; Matis, H. S.; Matulenko, Yu A.; McShane, T. S.; Meschanin, A.; Millane, J.; Miller, M. L.; Minaev, N. G.; Mioduszewski, Saskia; Mischke, A.; Mitchell, J.; Mohanty, B.; Morozov, D. A.; Munhoz, M. G.; Nandi, B. K.; Nattrass, C.; Nayak, T. K.; Nelson, J. M.; Nepali, C.; Netrakanti, P. K.; Ng, M. J.; Nogach, L. V.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Okada, H.; Okorokov, V.; Olson, D.; Pachr, M.; Page, B. S.; Pal, S. K.; Pandit, Y.; Panebratsev, Y.; Pawlak, T.; Peitzmann, T.; Perevoztchikov, V.; Perkins, C.; Peryt, W.; Phatak, S. C.; Planinic, M.; Pluta, J.; Poljak, N.; Poskanzer, A. M.; Potukuchi, B. V. K. S.; Prindle, D.; Pruneau, C.; Pruthi, N. K.; Putschke, J.; Raniwala, R.; Raniwala, S.; Ray, R. L.; Reed, R.; Ridiger, A.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Rose, A.; Roy, C.; Ruan, L.; Russcher, M. J.; Rykov, V.; Sahoo, R.; Sakrejda, I.; Sakuma, T.; Salur, S.; Sandweiss, J.; Sarsour, M.; Schambach, J.; Scharenberg, R. P.; Schmitz, N.; Seger, J.; Selyuzhenkov, I.; Seyboth, P.; Shabetai, A.; Shahaliev, E.; Shao, M.; Sharma, M.; Shi, S. S.; Shi, X. -H; Sichtermann, E. P.; Simon, F.; Singaraju, R. N.; Skoby, M. J.; Smirnov, N.; Snellings, R.; Sorensen, P.; Sowinski, J.; Spinka, H. M.; Srivastava, B.; Stadnik, A.; Stanislaus, T. D. S.; Staszak, D.; Strikhanov, M.; Stringfellow, B.; Suaide, A. A. P.; Suarez, M. C.; Subba, N. L.; Sumbera, M.; Sun, X. M.; Sun, Y.; Sun, Z.; Surrow, B.; Symons, T. J. M.; de Toledo, A. Szanto; Takahashi, J.; Tang, A. H.; Tang, Z.; Tarnowsky, T.; Thein, D.; Thomas, J. H.; Tian, J.; Timmins, A. R.; Timoshenko, S.; Tlusty; Tokarev, M.; Trainor, T. A.; Tram, V. N.; Trattner, A. L.; Trentalange, S.; Tribble, Robert E.; Tsai, O. D.; Ulery, J.; Ullrich, T.; Underwood, D. G.; Van Buren, G.; van Leeuwen, M.; Vander Molen, A. M.; Vanfossen, J. A.; Varma, R., Jr.; Vasconcelos, G. M. S.; Vasilevski, I. M.; Vasiliev, A. N.; Videbaek, F.; Vigdor, S. E.; Viyogi, Y. P.; Vokal, S.; Voloshin, S. A.; Wada, M.; Waggoner, W. T.; Wang, F.; Wang, G.; Wang, J. S.; Wang, Q.

    2009-01-01

    REVIEW C 79, 064903 (2009) Measurements of ? meson production in relativistic heavy-ion collisions at the BNL Relativistic Heavy Ion Collider (RHIC) B. I. Abelev,9 M. M. Aggarwal,30 Z. Ahammed,46 B. D. Anderson,19 D. Arkhipkin,13 G. S. Averichev,12 Y.... Bland,3 S.-L. Blyth,22 M. Bombara,2 B. E. Bonner,36 M. Botje,28 J. Bouchet,19 E. Braidot,28 A. V. Brandin,26 E. Bruna,51 S. Bueltmann,3 T. P. Burton,2 M. Bystersky,11 X. Z. Cai,39 H. Caines,51 M. Caldero?n de la Barca Sa?nchez,5 J. Callner,9 O. Catu,51...

  8. ERL-BASED LEPTON-HADRON COLLIDERS: eRHIC AND LHeC

    E-Print Network [OSTI]

    Zimmermann, F

    2013-01-01

    Two hadron-ERL colliders are being proposed. The Large Hadron electron Collider (LHeC) plans to collide the high-energy protons and heavy ions in the Large Hadron Collider (LHC) at CERN with 60-GeV polarized electrons or positrons. The baseline scheme for this facility adds to the LHC a separate recirculating superconducting (SC) lepton linac with energy recovery, delivering a lepton current of 6.4mA. The electron-hadron collider project eRHIC aims to collide polarized (and unpolarized) electrons with a current of 50 (220) mA and energies in the range 5–30 GeV with a variety of hadron beams— heavy ions as well as polarized light ions— stored in the existing Relativistic Heavy Ion Collider (RHIC) at BNL. The eRHIC electron beam will be generated in an energy recovery linac (ERL) installed inside the RHIC tunnel.

  9. THE RELATIVISTIC HEAVY ION COLLIDER (RHIC) CRYOGENIC SYSTEM AT BNL: REVIEW OF THE MODIFICATIONS AND UPGRADES SINCE 2002 AND PLANNED IMPROVEMENTS.

    SciTech Connect (OSTI)

    THAN,Y.R.; TUOZZOLO, J.; SIDI-YAKHLEF, A.; GANNI, V.; KNUDSEN, P.; ARENIUS, D.

    2007-07-16

    Brookhaven National Laboratory continues its multi-year program to improve the operational efficiency, reliability, and stability of the cryogenic system which also resulted in improved beam availability of the Relativistic Heavy Ion Collider (RHIC). This paper summarizes the work and changes made after each phase over the past four years to the present, as well as proposed future improvements. Power usage dropped from an initial 9.4 MW to the present 5.1 MW and is expected to drop below 5 MW after the completion of the remaining proposed improvements. The work proceeded in phases by balancing the Collider's schedule of operation, time required for the modifications and budget constraints. The main changes include process control, compressor oil removal and management, elimination of the use of cold compressors and two liquid helium storage tanks, insulation of the third liquid helium storage tank, compressor bypass flow reduction and the addition of a load turbine (Joule-Thompson expander) with associated heat exchangers at the cold end of the plant. Also, liquid helium pumps used for forced circulation of the sub-cooled helium through the magnet loops were eliminated by an accelerator supply flow reconfiguration. Planned future upgrades include the resizing of expanders 5 and 6 to increase their efficiencies.

  10. Breaking of the number-of-constituent-quark scaling for identified-particle elliptic flow as a signal of phase change in low-energy data taken at the BNL Relativistic Heavy Ion Collider (RHIC)

    E-Print Network [OSTI]

    J. Tian; J. H. Chen; Y. G. Ma; X. Z. Cai; F. Jin; G. L. Ma; S. Zhang; C. Zhong

    2009-06-29

    We argue that measurements of identified-particle elliptic flow in a wide energy range could shed light on the possible phase change in high-energy heavy ion collisions at the BNL Relativistic Heavy Ion Collider (RHIC). When the hadronization process is dominated by quark coalescence, the number-of-constituent-quark (NCQ) scaling for the identified-particle elliptic flow can serve as a probe for studying the strong interacting partonic matter. In the upcoming RHIC low-energy runs, the NCQ scaling behavior may be broken because of the change of the effective degrees of freedom of the hot dense matter, which corresponds to the transition from the dominant partonic phase to the dominant hadronic phase. A multiphase transport model is used to present the dependence of NCQ scaling behavior on the different hadronization mechanisms.

  11. Five Years of Tracking Heavy Ion Collisions at RHIC

    E-Print Network [OSTI]

    A. Franz

    2006-03-13

    Five years have passed since the first collisions of Au nuclei at the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL) on Long Island. With nucleon-nucleon center-of-mass energies of up to sqrt(s_NN)=200GeV RHIC provides the highest energy heavy ion collisions at any existing collider. To study the dynamics of nuclear matter at extreme temperatures and pressures hundreds of produced particles need to be tracked and identified, which provides a sizable challenge to the four experiments. This article tries to summarize these first years of RHIC operation from the detector point of view and give a glimpse at the future of the accelerator and its experiments.

  12. SETUP AND PERFORMANCE OF THE RHIC INJECTOR ACCELERATORS FOR THE 2005 RUN WITH COPPER IONS.

    SciTech Connect (OSTI)

    AHRENS, L.; ALESSI, J.; GARDNER, C.J.

    2005-05-16

    Copper ions for the 2005 run [1] of the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL) are accelerated in the Tandem, Booster and AGS prior to injection into RHIC. The setup and performance of these accelerators with copper are reviewed in this paper.

  13. COMMISSIONING OF THE RELATIVISTIC HEAVY ION COLLIDER.

    SciTech Connect (OSTI)

    TRBOJEVIC,D.; AHRENS,L.; BLASKIEWICZ,M.; BRENNAN,M.; BAI,M.; CAMERON,P.; CARDONA,J.; CONNOLLY,R.; ET AL; TSOUPAS,N.; VAN ZEIJTS,J.

    2001-06-18

    This report describes in detail steps performed in bringing the Relativistic Heavy Ion Collider (RHIC) from the commissioning into the operational stage when collisions between 60 bunches of fully striped gold ions, were routinely provided. Corrections of the few power supplies connections by the beam measurements are described. Beam lifetime improvements at injection, along the acceleration are shown. The beam diagnostic results; like Schottky detector, beam profile monitor, beam position monitors, tune meter and others, are shown [1].

  14. RHIC | Booster Synchrotron

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Beam Ion Source (EBIS), for the Relativistic Heavy Ion Collider (RHIC) and NASA Space Radiation Laboratory (NSRL) science programs. The workhorse injectors for nuclear physics...

  15. RHIC Performance as a 100 GeV Polarized Proton Collider in Run-9

    SciTech Connect (OSTI)

    Montag, C.; Ahrens, L.; Bai, M.; Beebe-Wang, J.; Blaskiewicz, M.; Brennan, J.M.; Brown, K.A.; Bruno, D.; Connolly, R.; DOttavio, T.; Drees, A.; Fedotov, A.V.; Fischer, W.; Ganetis, G.; Gardner, C.; Glenn, J.; Hahn, H.; Harvey, M.; Hayes, T.; Huang, H.; Ingrassia, P.; Jamilkowski, J.; Kayran, D.; Kewisch, J.; Lee, R.C.; Luccio, A.U.; Luo, Y.; MacKay, W.W.; Makdisi, Y.; Malitsky, N.; Marr, G.; Marusic, A.; Menga, P.M.; Michnoff, R.; Minty, M.; Morris, J.; Oerter, B.; Pilat, F.; Pile, P.; Pozdeyev, E.; Ptitsyn, V.; Robert-Demolaize, G.; Roser, T.; Russo, T.; Satogata, T.; Schoefer, V.; Schultheiss, C.; Severino, F.; Sivertz, M.; Smith, K.; Tepikian, S.; Thieberger, P.; Trbojevic, D.; Tsoupas, N.; Tuozzolo, J.; Zaltsman, A.; Zelenski, A.; Zeno, K.; Zhang, S.Y.

    2010-05-23

    During the second half of Run-9, the Relativisitc Heavy Ion Collider (RHIC) provided polarized proton collisions at two interaction points. The spin orientation of both beams at these collision points was controlled by helical spin rotators, and physics data were taken with different orientations of the beam polarization. Recent developments and improvements will be presented, as well as luminosity and polarization performance achieved during Run-9.

  16. Medium energy heavy ion operations at RHIC

    SciTech Connect (OSTI)

    Drees, K.A.; Ahrens, L.; Bai, M.; Beebe-Wang, J.; Blackler, I.M.C.; Blaskiewicz, M.; Brown, K.A.; Brennan, M.; Bruno, D.; Butler, J.; Carlson, C.; Connolly, R.; D'Ottavio, T.; Fischer, W.; Fu, W.; Gassner, D.; Harvey, M.; Hayes, T.; Huang, H.; Hulsart, R.; Ingrassia, P.; Kling, N.; Lafky, M.; Laster, J.; Lee, R.C.; Litvinenko, V.; Luo, Y.; MacKay, W.W.; Marr, G.; Mapes. M.; Marusic, A.; Mernick, K.; Michnoff, R.; Minty, M.; Montag, C.; Morris, J.; Naylor, C.; Nemesure, S.; Pilat, F.; Ptitsyn, V.; Robert-Demolaize, G.; Roser, T.; Sampson, P.; Satogata, T.; Schoefer, V.; Schultheiss, C.; Severino, F.; Shrey, T.; Smith, K.S.; Tepikian, S.; Thieberger, P.; Trbojevic, D.; Tsoupas, N.; Tuozzolo, J.; van Kuik, B.; Wilinski, M.; Zaltsman, A.; Zeno, K.; Zhang, S.Y.

    2011-03-28

    As part of the search for a phase transition or critical point on the QCD phase diagram, an energy scan including 5 different energy settings was performed during the 2010 RHIC heavy ion run. While the top beam energy for heavy ions is at 100 GeV/n and the lowest achieved energy setpoint was significantly below RHICs injection energy of approximately 10 GeV/n, we also provided beams for data taking in a medium energy range above injection energy and below top beam energy. This paper reviews RHIC experience and challenges for RHIC medium energy operations that produced full experimental data sets at beam energies of 31.2 GeV/n and 19.5 GeV/n. The medium energy AuAu run covered two beam energies, both above the RHIC injection energy of 9.8 GeV but well below the standard store energy of 100 GeV (see table 1). The low energy and full energy runs with heavy ions in FY10 are summarized in [1] and [2]. Stochastic Cooling ([3]) was only used for 100 GeV beams and not used in the medium energy run. The efficiency of the transition from 100 GeV operation to 31.2 GeV and then to 19.5 GeV was remarkable. Setup took 32 h and 19 h respectively for the two energy settings. The time in store, defined to be the percentage of time RHIC provides beams in physics conditions versus calendar time, was approximately 52% for the entire FY10 heavy ion run. In both medium energy runs it was well above this average, 68% for 31.5 GeV and 82% for 19.5 GeV. For both energies RHIC was filled with 111 bunches with 1.2 10{sup 9} and 1.3 10{sup 9} ions per bunch respectively.

  17. Higher order QED in high-mass e{sup +}e{sup -} pair production at energies available at the BNL Relativistic Heavy Ion Collider (RHIC)

    SciTech Connect (OSTI)

    Baltz, Anthony J.; Nystrand, Joakim

    2010-08-15

    Lowest order and higher order QED calculations have been carried out for the RHIC high mass e{sup +}e{sup -} pairs observed by PHENIX with single zero-degree-calorimeter triggers. The lowest order QED results for the experimental acceptance are about two standard deviations larger than the PHENIX data. Corresponding higher order QED calculations are within one standard deviation of the data.

  18. The Electron-Ion Collider

    E-Print Network [OSTI]

    V. Guzey

    2009-07-23

    The future Electron-Ion Collider (EIC) is a proposed new facility to collide high-energy electrons with beams of polarized protons/light nuclei and unpolarized nuclei. We overview the goals of the project and key measurements at the EIC. We also briefly comment on recent developments of the project.

  19. Observation of snake resonances at Relativistic Heavy Ion Collider

    SciTech Connect (OSTI)

    Bai, M.; Ahrens, L.; Alekseev, I.G.; Alessi, J.; et al

    2010-09-27

    The Siberian snakes are powerful tools in preserving polarization in high energy accelerators has been demonstrated at the Brookhaven Relativistic Heavy Ion Collider (RHIC). Equipped with two full Siberian snakes in each ring, polarization is preserved during acceleration from injection to 100 GeV. However, the Siberian snakes also introduce a new set of depolarization resonances, i.e. snake resonances as first discovered by Lee and Tepikian. The intrinsic spin resonances above 100 GeV are about a factor of two stronger than those below 100 GeV which raises the challenge to preserve the polarization up to 250 GeV. In 2009, polarized protons collided for the first time at the RHIC design store energy of 250 GeV. This paper presents the experimental measurements of snake resonances at RHIC. The plan for avoiding these resonances is also presented.

  20. THE RHIC ACCELERATOR.

    SciTech Connect (OSTI)

    HARRISON,M.; PEGGS,S.; ROSER,T.

    2002-01-01

    This review discusses the design and initial operation of the Relativistic Heavy Ion Collider (RHIC), noting the novel features of a heavy ion collider that are distinct from conventional hadron colliders. These features reflect the experimental requirements of operation with a variety of ion species over a wide energy range, including collisions between ions of unequal energies and polarized protons. Other unique aspects of RHIC include intrabeam scattering, interaction-region error compensation, and transition crossing with a slow ramp rate. The RHIC facility has just completed the second physics run after beam commissioning in 2000.

  1. Jets in heavy ion collisions at RHIC

    E-Print Network [OSTI]

    Jan Kapitan

    2009-11-25

    Full jet reconstruction in heavy-ion collisions enables a complete study of the modification of jet structure due to energy loss in hot and dense QCD matter, but is challenging due to the high multiplicity environment. The STAR and PHENIX collaborations at RHIC have recently presented measurements of fully reconstructed jets from p+p, Cu+Cu and Au+Au collisions at $\\sqrt{s_\\mathrm{NN}} = 200 \\mathrm{GeV}$. We review the first results on inclusive jet spectra, di-jets and fragmentation functions and discuss their implications on understanding of jet quenching.

  2. RHIC performance for FY2011 Au+Au heavy ion run

    SciTech Connect (OSTI)

    Marr, G.; Ahrens, L.; Bai, M.; Beebe-Wang, J.; Blackler, I.; Blaskiewicz, M.; Brennan, J.M.; Brown, K.A.; Bruno, D.; Butler, J.; Carlson, C.; Connolly, R.; D'Ottavio, T.; Drees, K.A.; Fedotov, A.V.; Fischer, W.; Fu, W.; Gardner, C.J.; Gassner, D.M.; Glenn, J.W.; Gu, X.; Harvey, M.; Hayes, T.; Hoff, L.; Huang, H.; Ingrassia, P.F.; Jamilkowski, J.P.; Kling, N.; Lafky, M.; Laster, J.S.; Liu, C.; Luo, Y.; Mapes, M.; Marusic, A.; Mernick, K.; Michnoff, R.J.; Minty, M.G.; Montag, C.; Morris, J.; Naylor, C.; Nemesure, S.; Polizzo, S.; Ptitsyn, V.; Robert-Demolaize, G.; Roser, T.; Sampson, P.; Sandberg, J.; Schoefer, V.; Schultheiss, C.; Severino, F.; Shrey, T.; Smith, K.; Steski, D.; Tepikian, S.; Thieberger, P.; Trbojevic, D.; Tsoupas, N.; Tuozzolo, J.E.; VanKuik, B.; Wang, G.; Wilinski, M.; Zaltsman, A.; Zeno, K.; Zhang, S.Y.

    2011-09-04

    Following the Fiscal Year (FY) 2010 (Run-10) Relativistic Heavy Ion Collider (RHIC) Au+Au run, RHIC experiment upgrades sought to improve detector capabilities. In turn, accelerator improvements were made to improve the luminosity available to the experiments for this run (Run-11). These improvements included: a redesign of the stochastic cooling systems for improved reliability; a relocation of 'common' RF cavities to alleviate intensity limits due to beam loading; and an improved usage of feedback systems to control orbit, tune and coupling during energy ramps as well as while colliding at top energy. We present an overview of changes to the Collider and review the performance of the collider with respect to instantaneous and integrated luminosity goals. At the conclusion of the FY 2011 polarized proton run, preparations for heavy ion run proceeded on April 18, with Au+Au collisions continuing through June 28. Our standard operations at 100 GeV/nucleon beam energy was bracketed by two shorter periods of collisions at lower energies (9.8 and 13.5 GeV/nucleon), continuing a previously established program of low and medium energy runs. Table 1 summarizes our history of heavy ion operations at RHIC.

  3. Mechanical design of 56 MHz superconducting RF cavity for RHIC collider

    SciTech Connect (OSTI)

    Pai, C.; Ben-Zvi, I.; Burrill, A.; Chang, X.; McIntyre, G.; Than, Y.; Tuozzolo, J.; Wu, Q.

    2011-03-28

    A 56 MHz Superconducting RF Cavity operating at 4.4K is being constructed for the RHIC collider. This cavity is a quarter wave resonator with beam transmission along the centerline. This cavity will increase collision luminosity by providing a large longitudinal bucket for stored bunches of RHIC ion beam. The major components of this assembly are the niobium cavity with the mechanical tuner, its titanium helium vessel and vacuum cryostat, the support system, and the ports for HOM and fundamental dampers. The cavity and its helium vessel must meet equivalent safety with the ASME pressure vessel code and it must not be sensitive to frequency shift due to pressure fluctuations from the helium supply system. Frequency tuning achieved by a two stage mechanical tuner is required to meet performance parameters. This tuner mechanism pushes and pulls the tuning plate in the gap of niobium cavity. The tuner mechanism has two separate drive systems to provide both coarse and fine tuning capabilities. This paper discusses the design detail and how the design requirements are met.

  4. Coordinating the 2009 RHIC Run

    ScienceCinema (OSTI)

    Brookhaven Lab - Mei Bai

    2010-01-08

    Physicists working at the Brookhaven National Lab's Relativistic Heavy Ion Collider (RHIC) are exploring the puzzle of proton spin as they begin taking data during the 2009 RHIC run. For the first time, RHIC is running at a record energy of 500 giga-elect

  5. Colliding Nuclei at High Energy

    ScienceCinema (OSTI)

    Brookhaven Lab

    2010-01-08

    Physicist Peter Steinberg explains what happens when atomic nucleii travelling at close to the speed of light smash together in Brookhaven Lab's Relativistic Heavy Ion Collider (RHIC).

  6. ERL BASED ELECTRON-ION COLLIDER ERHIC.

    SciTech Connect (OSTI)

    LITVINENKO,V.N.; BEN-ZVI,I.; ANDERSON,D.; ET AL.

    2005-05-16

    In this paper we describe eRHIC design based on the RHIC hadron rings and 10-to-20 GeV energy recovery electron linac. RHIC requires a very large tunability range for c.m. energies while maintaining very high luminosity up to 10{sup 34} cm{sup -2} s{sup -1} per nucleon. The designs of this future polarized electron-hadron collider, eRHIC, based on a high current super-conducting energy-recovery linac (ERL) with energy of electrons up to 20 GeV, have a number of specific requirements on the ERL optics. Two of the most attractive features of this scheme are full spin transparency of the ERL at all operational energies and the capability to support up to four interaction points. We present two main layouts of the eRHIC, the expected beam and luminosity parameter, and discuss the potential limitation of its performance. Two of the most attractive features of this scheme are full spin transparency of the ERL at all operational energies and the capability to support up to four interaction points. We present two main layouts of the eRHIC, the expected beam and luminosity parameter, and discuss the potential limitation of its performance.

  7. RHIC R&D -eCooling Annual DOE/Nuclear Physics Review

    E-Print Network [OSTI]

    &D effort by Ilan Ben-Zvi, Collider-Accelerator Department Brookhaven National Laboratory #12;The RHIC II Booster AGS RHIC II Electron cooling IP2 Location of cooler: IP2 Objective: Cool RHIC stored ion beamsRHIC R&D - eCooling Annual DOE/Nuclear Physics Review of RHIC Science and Technology July 24

  8. Chiral electric field in relativistic heavy-ion collisions at energies available at the BNL Relativistic Heavy Ion Collider and at the CERN Large Hadron Collider

    E-Print Network [OSTI]

    Yang Zhong; Chun-Bin Yang; Xu Cai; Sheng-Qin Feng

    2015-10-03

    It was proposed that the electric fields may lead to chiral separation in QGP, which is called the chiral electric separation effect. The strong electromagnetic field and the QCD vacuum can both completely be produced in the off-central nuclear-nuclear collision. We used the Wood-Saxon nucleon distribution to calculate the electric field distributions of the off-central collisions. The chiral electro field spatial distribution at Relativistic Heavy-Ion Collider (RHIC) and Large Hadron Collider (LHC) energy regions are systematically studied in this paper. Compared with magnetic field spatial distribution, electric field shows some different features in relativistic heavy-ion collisions. The dependence of the electric field produced by the thermal quark in the central position with different impact parameters on the proper time with different collision energies in the RHIC and LHC energy region are studied in this paper.

  9. Ion polarization in the MEIC figure-8 ion collider ring

    SciTech Connect (OSTI)

    V.S. Morozov, Ya.S. Derbenev, Y. Zhang, P. Chevtsov, A.M. Kondratenko, M.A. Kondratenko, Yu.N. Filatov

    2012-07-01

    The nuclear physics program envisaged at the Medium-energy Electron-Ion Collider (MEIC) currently being developed at the Jefferson Lab calls for collisions of 3-11 GeV/c longitudinally polarized electrons and 20-100 GeV/c, in equivalent proton momentum, longitudinally/ transversely polarized protons/ deuterons/ light ions. We present a scheme that provides the required ion polarization arrangement in the MEIC's ion collider ring.

  10. Hot topics in ultra-peripheral ion collisions

    E-Print Network [OSTI]

    2001-01-01

    ratio for the proposed eRHIC electron-ion collider. Figurethe LHC, compared with that expected at the proposed eRHIC.2 The eRHIC curve has been multiplied by 6000, the ratio of

  11. RHIC - Exploring the Universe Within

    ScienceCinema (OSTI)

    BNL

    2009-09-01

    A guided tour of Brookhaven's Relativistic Heavy Ion Collider (RHIC) conducted by past Laboratory Director John Marburger. RHIC is a world-class scientific research facility that began operation in 2000, following 10 years of development and construction. Hundreds of physicists from around the world use RHIC to study what the universe may have looked like in the first few moments after its creation. RHIC drives two intersecting beams of gold ions head-on, in a subatomic collision. What physicists learn from these collisions may help us understand more about why the physical world works the way it does, from the smallest subatomic particles, to the largest stars.

  12. The Smallest Drops of the Hottest Matter? New Investigations at the Relativistic Heavy Ion Collider (493rd Brookhaven Lecture)

    SciTech Connect (OSTI)

    Sickles, Anne

    2014-03-19

    Pool sharks at the billiards hall know that sometimes you aim to rocket the cue ball for a head-on collision, and other times, a mere glance will do. Physicists need to know more than a thing or two about collision geometry too, as they sift through data from the billions of ions that smash together at the Relativistic Heavy Ion Collider (RHIC). Determining whether ions crash head-on or just glance is crucial for the physicists analyzing data to study quark-gluon plasma—the ultra-hot, "perfect" liquid of quarks and gluons that existed more than 13 billion years ago, before the first protons and neutrons formed. For these physicists, collision geometry data provides insights about quark-gluon plasma's extremely low viscosity and other unusual properties, which are essential for understanding more about the "strong force" that holds together the nucleus, protons, and neutrons of every atom in the universe. Dr. Sickles explains how physicists use data collected at house-sized detectors like PHENIX and STAR to determine what happens before, during, and after individual particle collisions among billions at RHIC. She also explains how the ability to collide different "species" of nuclei at RHIC—including protons and gold ions today and possibly more with a proposed future electron-ion collider upgrade (eRHIC)—enables physicists to probe deeper into the mysteries of quark-gluon plasma and the strong force.

  13. Relativistic Heavy Ion Physics: Results from AGS to RHIC

    E-Print Network [OSTI]

    Peter Steinberg

    2002-10-04

    High-energy collisions of heavy ions provide a means to study QCD in a regime of high parton density, and may provide insight into its phase structure. Results from the four experiments at RHIC (BRAHMS, PHENIX, PHOBOS and STAR) are presented, and placed in context with the lower energy data from the AGS and SPS accelerators. The focus is on the insights these measurements provide into the time history of the collision process. Taken together, the data point to the creation of a deconfined state of matter that forms quickly, expands rapidly and freezes out suddenly.

  14. Energy loss of coasting gold ions and deuterons in RHIC.

    SciTech Connect (OSTI)

    Abreu,N.; Blaskiewicz, M.; Brown, K.A.; Butler, J.J.; FischW; Harvey, M.; Tepikian, S.

    2008-06-23

    The total energy loss of coasting gold ion beams was measured at RHIC at two energies, corresponding to a gamma of 75.2 and 107.4. We describe the experiment and observations and compare the measured total energy loss with expectations from ionization losses at the residual gas, the energy loss due to impedance and synchrotron radiation. We find that the measured energy losses are below what is expected from free space synchrotron radiation. We believe that this shows evidence for suppression of synchrotron radiation which is cut off at long wavelength by the presence of the conducting beam pipe.

  15. LHeC and eRHIC

    SciTech Connect (OSTI)

    Litvinenko,V.

    2009-07-16

    This paper is focused on possible designs and predicted performances of two proposed high-energy, high-luminosity electron-hadron colliders: eRHIC at Brookhaven National Laboratory (BNL, Upton, NY, USA) and LHeC at Organisation Europeenne pour la Recherche Nucleaire (CERN, Geneve, Switzerland). The Relativistic Heavy Ion Collider (RHIC, BNL) and the Large Hadron Collider (LHC, CERN) are designed as versatile colliders. RHIC is colliding various species of hadrons staring from polarized protons to un-polarized heavy ions (such as fully stripped Au (gold) ions) in various combinations: polarized p-p, d-Au, Cu-Cu, Au-Au. Maximum energy in RHIC is 250 GeV (per beam) for polarized protons and 100 GeV/n for heavy ions. There is planed expansion of the variety of species to include polarized He{sup 3} and unpolarized fully stripped U (uranium). LHeC is designed to collide both un-polarized protons with energy up to 7 TeV per beam and fully stripped Pb (lead) ions with energy up to 3 TeV/n. Both eRHIC and LHeC plan to add polarized electrons (or/and positrons) to the list of colliding species in these versatile hadron colliders. In eRHIC 10-20 GeV electrons would collide with hadrons circulating in RHIC. In LHeC 50-150 GeV polarized leptons will collided with LHC's hadron beams. Both colliders plan to operate in electron-proton (in RHIC case protons are polarized as well) and electron-ion collider modes. eRHIC and LHeC colliders are complimentary both in the energy reach and in their physics goals. I will discuss in this paper possible choices of the accelerator technology for the electron part of the collider for both eRHIC and LHeC, and will present predicted performance for the colliders. In addition, possible staging scenarios for these colliders will be discussed.

  16. Development of a polarized Helium-3 ion source for RHIC using the electron beam ion source

    E-Print Network [OSTI]

    Epstein, Charles Samuel

    2013-01-01

    This thesis presents my work on the design and development of a source of polarized Helium-3 ions for the Relativistic Heavy Ion Collider at Brookhaven National Lab, Upton, NY. The 3He atoms will be polarized using the ...

  17. Loss maps of RHIC

    SciTech Connect (OSTI)

    Robert-Demolaize,G.

    2007-10-01

    State-of-the-art tracking tools were recently developed at CERN to study the cleaning efficiency of the Large Hadron Collider (LHC) collimation system [1]. These tools are fully transportable, meaning that any accelerator lattice that includes a collimation system can be simulated. Each of the two Relativistic Heavy Ion Collider (RHIC) [2] beam lines features a multi-stage collimation system, therefore dedicated datasets from RHIC operations with proton beams can be used to benchmark the tracking codes and assess the accuracy of the predicted hot spots along the LHC.

  18. The study of background electric field in relativistic heavy-ion collisions in the RHIC and LHC energy regions

    E-Print Network [OSTI]

    Zhong, Yang; Cai, Xu; Feng, Sheng-Qin

    2015-01-01

    It was proposed that the electric fields may lead to chiral separation in QGP, which is called the chiral electric separation effect. The strong electromagnetic field and the QCD vacuum can both completely be produced in the off-central nuclear-nuclear collision. Based on the theory of Kharzeev, McLerran, and Warringa, we used the Wood-Saxon nucleon distribution to replace that of the uniform distribution to improve the electric field calculation method of the off-central collision. The chiral electro field distribution at Relativistic Heavy-Ion Collider (RHIC) and Large Hadron Collider (LHC) energy regions are systematically studied in this paper. Compared with magnetic field spatial distribution, electric field shows some different features in relativistic heavy-ion collisions.

  19. Identified particle production and freeze-out properties in heavy-ion collisions at RHIC Beam Energy Scan program

    E-Print Network [OSTI]

    Sabita Das

    2014-12-01

    The first phase of Beam Energy Scan (BES) program at the Relativistic Heavy-Ion Collider (RHIC) was started in the year 2010 with the aim to study the several aspects of the quantum chromodynamics (QCD) phase diagram. The Solenoidal Tracker At RHIC (STAR) detector has taken data at $\\sqrt{s_{NN}} = $ 7.7, 11.5, 19.6, 27, and 39 GeV in Au+Au collisions in the years 2010 and 2011 as part of the BES programme. For these beam energies, we present the results on the particle yields, average transverse mass and particle ratios for identified particles in mid-rapidity ($|y|$ chemical freeze-out dynamics within the framework of a statistical model.

  20. Unveiling the Proton Spin Decomposition at a Future Electron-Ion Collider

    E-Print Network [OSTI]

    Aschenauer, Elke C; Stratmann, M

    2015-01-01

    We present a detailed assessment of how well a future Electron-Ion Collider could constrain helicity parton distributions in the nucleon and, therefore, unveil the role of the intrinsic spin of quarks and gluons in the proton's spin budget. Any remaining deficit in this decomposition will provide the best indirect constraint on the contribution due to the total orbital angular momenta of quarks and gluons. Specifically, all our studies are performed in the context of global QCD analyses based on realistic pseudo-data and in the light of the most recent data obtained from polarized proton-proton collisions at BNL-RHIC that have provided evidence for a significant gluon polarization in the accessible, albeit limited range of momentum fractions. We also present projections on what can be achieved on the gluon's helicity distribution by the end of BNL-RHIC operations. All estimates of current and projected uncertainties are performed with the robust Lagrange multiplier technique.

  1. Optics measurement and correction during beam acceleration in the Relativistic Heavy Ion Collider

    SciTech Connect (OSTI)

    Liu, C.; Marusic, A.; Minty, M.

    2014-09-09

    To minimize operational complexities, setup of collisions in high energy circular colliders typically involves acceleration with near constant ?-functions followed by application of strong focusing quadrupoles at the interaction points (IPs) for the final beta-squeeze. At the Relativistic Heavy Ion Collider (RHIC) beam acceleration and optics squeeze are performed simultaneously. In the past, beam optics correction at RHIC has taken place at injection and at final energy with some interpolation of corrections into the acceleration cycle. Recent measurements of the beam optics during acceleration and squeeze have evidenced significant beta-beats which if corrected could minimize undesirable emittance dilutions and maximize the spin polarization of polarized proton beams by avoidance of higher-order multipole fields sampled by particles within the bunch. In this report the methodology now operational at RHIC for beam optics corrections during acceleration with simultaneous beta-squeeze will be presented together with measurements which conclusively demonstrate the superior beam control. As a valuable by-product, the corrections have minimized the beta-beat at the profile monitors so reducing the dominant error in and providing more precise measurements of the evolution of the beam emittances during acceleration.

  2. Operational head-on beam-beam compensation with electron lenses in the Relativistic Heavy Ion Collider

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Fischer, W.; Gu, X.; Altinbas, Z.; Costanzo, M.; Hock, J.; Liu, C.; Luo, Y.; Marusic, A.; Michnoff, R.; Miller, T. A.; et al

    2015-12-23

    Head-on beam-beam compensation has been implemented in the Relativistic Heavy Ion Collider (RHIC) in order to increase the luminosity delivered to the experiments. We discuss the principle of combining a lattice for resonance driving term compensation and an electron lens for tune spread compensation. We describe the electron lens technology and its operational use. As of this date the implemented compensation scheme approximately doubled the peak and average luminosities.

  3. RHIC The Perfect Liquid

    ScienceCinema (OSTI)

    BNL

    2009-09-01

    Evidence to date suggests that gold-gold collisions the Relativistic Heavy Ion Collider at Brookhaven are indeed creating a new state of hot, dense matter, but one quite different and even more remarkable than had been predicted. Instead of behaving like a gas of free quarks and gluons, as was expected, the matter created in RHIC's heavy ion collisions appears to be more like a "perfect" liquid.

  4. Heavy-quark probes of the quark-gluon plasma and interpretation of recent data taken at the BNL Relativistic Heavy Ion Collider 

    E-Print Network [OSTI]

    van Hees, H.; Greco, V.; Rapp, Ralf.

    2006-01-01

    strongly interacting QGP (sQGP), as well as parton coalescence, can play an essential role in the interpretation of recent data from the BNL Relativistic Heavy-Ion Collider (RHIC), and thus illuminate the nature of the sQGP and its hadronization. Our main...

  5. eRHIC - Accelerator and detector design studies

    E-Print Network [OSTI]

    Surrow, B

    2006-01-01

    An electron-proton/ion collider facility (eRHIC) is under consideration at Brookhaven National Laboratory (BNL). An overview of the accelerator and detector design concepts will be provided.

  6. RHIC physics overview

    E-Print Network [OSTI]

    Lijuan Ruan

    2010-07-16

    The results from data taken during the last several years at the Relativistic Heavy-Ion Collider (RHIC) will be reviewed in the paper. Several selected topics that further our understanding of constituent quark scaling, jet quenching and color screening effect of heavy quarkonia in the hot dense medium will be presented. Detector upgrades will further probe the properties of Quark Gluon Plasma. Future measurements with upgraded detectors will be presented. The discovery perspectives from future measurements will also be discussed.

  7. Probing the Color Glass Condensate in an electron-ion collider

    E-Print Network [OSTI]

    M. S. Kugeratski; V. P. Goncalves; F. S. Navarra

    2006-02-24

    Perturbative Quantum Chromodynamics (pQCD) predicts that the small-$x$ gluons in a hadron wavefunction should form a Color Glass Condensate (CGC), characterized by a saturation scale $Q_s (x, A)$ which is energy and atomic number dependent. In this paper we study the predictions of CGC physics for electron - ion collisions at high energies. We consider that the nucleus at high energies acts as an amplifier of the physics of high parton densities and estimate the nuclear structure function $F_2^A(x,Q^2)$, as well as the longitudinal and charm contributions, using a generalization for nuclear targets of the Iancu-Itakura-Munier model which describes the $ep$ HERA data quite well. Moreover, we investigate the behavior of the logarithmic slopes of the total and longitudinal structure functions in the kinematical region of the future electron - ion collider eRHIC.

  8. IBS suppression lattice in RHIC: theory and experimental verification

    SciTech Connect (OSTI)

    Fedotov,A.V.; Bai, M.; Bruno, D.; Cameron, P.; Connolly, R.; Cupolo, J.; Della Penna, A.; Drees, A.; Fischer, W.; Ganetis, G.; Hoff, L.; Litvinenko, V.N.; Louie, W.; Luo, Y.; Malitsky, N.; Marr, G.; Marusic, A.; Montag, C.; Ptitsyn, V.; Roser, T.; Satogata, T.; Tepikian, S.; Trbojevic, D.; Tsoupas, N.

    2008-08-25

    Intra-beam scattering (IBS) is the limiting factor of the luminosity lifetime for Relativistic Heavy Ion Collider (RHIC) operation with heavy ions. Over the last few years the process of IBS was carefully studied in RHIC with dedicated IBS measurements and their comparison with the theoretical models. A new lattice was recently designed and implemented in RHIC to suppress transverse IBS growth, which lowered the average arc dispersion by about 20% [1]. This lattice became operational during RHIC Run-8. We review the IBS suppression mechanism, IBS measurements before and after the lattice change, and comparisons with predictions.

  9. RHIC Polarized proton performance in run-8

    SciTech Connect (OSTI)

    Montag,C.; Bai, M.; MacKay, W.W.; Roser, T.; Abreu, N.; Ahrens, L.; Barton, D.; Beebe-Wang, J.; Blaskiewicz, M.; Brennan, J.M.; Brown, K.A.; Bruno, D.; Bunce, G.; Calaga, R.; Cameron, P.; Connolly, R.; D'Ottavio, T.; Drees, A.; Fedotov, A.V.; Fischer, W.; Ganetis, G.; Gardner, C.; Glenn, J.; Hayes, T.; Huang, H.; Ingrassia, P.; Kayran, D.A.; Kewisch, J.; Lee, R.C.; Lin, F.; Litvinenko, V.N.; Luccio, A.U.; Luo, Y.; Makdisi, Y.; Malitsky, N.; Marr, G.; Marusic, A.; Michnoff, R.; Morris, J.; Oerter, B.; Pilat, F.; Pile, P.; Robert-Demolaize, G.; Russo, T.; Satogata, T.; Schultheiss, C.; Sivertz, M.; Smith, K.; Tepikian, S.; D. Trbojevic, D.; Tsoupas, N.; Tuozzolo, J.; Zaltsman, A.; Zelenski, A.; Zeno, K.; Zhang, S.Y.

    2008-10-06

    During Run-8, the Relativistic Heavy Ion Collider (RHIC) provided collisions of spin-polarized proton beams at two interaction regions. Physics data were taken with vertical orientation of the beam polarization, which in the 'Yellow' RHIC ring was significantly lower than in previous years. We present recent developments and improvements as well as the luminosity and polarization performance achieved during Run-8, and we discuss possible causes of the not as high as previously achieved polarization performance of the 'Yellow' ring.

  10. FEL potential of eRHIC

    SciTech Connect (OSTI)

    Litvinenko, V.N.; Ben-Zvi, I.; Hao, Y.; Kao, C-C.; Kayran, D.; Murphy, J.B.; Ptitsyn, V.; Trbojevic, D.; Tsoupas, N.

    2010-08-23

    Brookhaven National Laboratory plans to build a 5-to-30 GeV energy-recovery linac (ERL) for its future electron-ion collider, eRHIC. In past few months, the Laboratory turned its attention to the potential of this unique machine for free electron lasers (FELS), which we initially assessed earlier. In this paper, we present our current vision of a possible FEL farm, and of narrow-band FEL-oscillators driven by this accelerator. eRHIC, the proposed electron-ion collider at BNL, takes advantage of the existing Relativistic Heavy Ion Collider (RHIC) complex. Plans call for adding a six-pass super-conducting (SRF) ERL to this complex to collide polarized- and unpolarized- electron beams with heavy ions (with energies up to 130 GeV per nucleon) and with polarized protons (with energies up to 325 GeV). RHIC, with a circumference of 3.834 km, has three-fold symmetry and six straight sections each {approx} 250 m long. Two of these straight sections will accommodate 703-MHz SRF linacs. The maximum energy of the electron beam in eRHIC will be reached in stages, from 5 GeV to 30 GeV, by increasing the lengths of its SRF linacs. We plan to install at the start the six-pass magnetic system with small gap magnets. The structure of the eRHIC's electron beam will be identical with that of its hadron beam, viz., 166 bunches will be filled, reserving about a one-microsecond gap for the abort kicker. With modest modifications, we can assure that eRHIC's ERL will become an excellent driver for continuous wave (CW) FELs (see Fig.1). The eRHIC's beam structure will support the operation of several such FELs in parasitic mode.

  11. FY2014 Parameters for Gold Ions in Booster, AGS, and RHIC

    SciTech Connect (OSTI)

    Gardner, C. J.

    2014-07-30

    The nominal parameters for gold ions in Booster, AGS, and RHIC are given for the FY2014 running period. The parameters are worked out using various formulas to derive mass, kinetic parameters, RF parameters, ring parameters, etc.. The ''standard setup'', ''medium-energy'', and ''low-energy'' parameters are summarized in separate sections.

  12. FY2014 Parameters for Helions and Gold Ions in Booster, AGS, and RHIC

    SciTech Connect (OSTI)

    Gardner, C. J.

    2014-08-15

    The nominal parameters for helions (helion is the bound state of two protons and one neutron, the nucleus of a helium-3 atom) and gold ions in Booster, AGS, and RHIC are given for the FY2014 running period. The parameters are found using various formulas to derive mass, helion anomalous g-factor, kinetic parameters, RF parameters, ring parameters, etc..

  13. Rapidity losses in heavy-ion collisions from AGS to RHIC energies

    E-Print Network [OSTI]

    F. C. Zhou; Z. B. Yin; D. C. Zhou

    2009-09-28

    We study the rapidity losses in central heavy-ion collisions from AGS to RHIC energies with the mean rapidity determined from the projectile net-baryon distribution after collisions. The projectile net-baryon distribution in the full rapidity range was obtained by removing the target contribution phenomenologically at forward rapidity region from the experimental net-baryon measurements and taking into account the projectile contribution at backward rapidity region. Based on the full projectile net-baryon distributions, calculation results show that the rapidity loss stops increasing from the SPS top energy to RHIC energies, indicating that baryon transport does not depend strongly on energy at high energies.

  14. Nuclear physics with a medium-energy Electron-Ion Collider

    E-Print Network [OSTI]

    A. Accardi; V. Guzey; A. Prokudin; C. Weiss

    2011-10-05

    A polarized ep/eA collider (Electron-Ion Collider, or EIC) with variable center-of-mass energy sqrt(s) ~ 20-70 GeV and a luminosity ~ 10^{34} cm^{-2} s^{-1} would be uniquely suited to address several outstanding questions of Quantum Chromodynamics (QCD) and the microscopic structure of hadrons and nuclei: (i) the three-dimensional structure of the nucleon in QCD (sea quark and gluon spatial distributions, orbital motion, polarization, correlations); (ii) the fundamental color fields in nuclei (nuclear parton densities, shadowing, coherence effects, color transparency); (iii) the conversion of color charge to hadrons (fragmentation, parton propagation through matter, in-medium jets). We briefly review the conceptual aspects of these questions and the measurements that would address them, emphasizing the qualitatively new information that could be obtained with the collider. Such a medium-energy EIC could be realized at Jefferson Lab after the 12 GeV Upgrade (MEIC), or at Brookhaven National Lab as the low-energy stage of eRHIC.

  15. RHIC PERFORMANCE DURING THE FY10 200 GeV Au+Au HEAVY ION RUN

    SciTech Connect (OSTI)

    Brown, K.A.; Ahrens, L.; Bai, M.; Beebe-Wang, J.; Blaskiewicz, M.; Brennan, J.; Bruno, D.; Carlson, C.; Connolly, R.; de Maria, R.; D’Ottavio, T.; Drees, A.; Fischer, W.; Fu, W.; Gardner, C.; Gassner, D.; Glenn, J.W.; Hao, Y.; Harvey, M.; Hayes, T.; Hoff, L.; Huang, H.; Laster, J.; Lee, R.; Litvinenko, V.; Luo, Y.; MacKay, W.; Marr, G.; Marusic, A.; Mernick, K.; Michnoff, R.; Minty, M.; Montag, C.; Morris, J.; Nemesure, S.; Oerter, B.; Pilat, F.; Ptitsyn, V.; Robert-Demolaize, G.; Roser, T.; Russo, T.; Sampson, P.; Sandberg, J.; Satogata, T.; Severino, F.; Schoefer, V.; Schultheiss, C.; Smith, K.; Steski, D.; Tepikian, S.; Theisen, C.; Thieberger, P.; Trbojevic, D.; Tsoupas, N.; Tuozzolo, J.; Wang, G.; Wilinski, M.; Zaltsman, A.; Zeno, K.; Zhang, S.Y.

    2010-05-23

    Since the last successful RHIC Au+Au run in 2007 (Run-7), the RHIC experiments have made numerous detector improvements and upgrades. In order to benefit from the enhanced detector capabilities and to increase the yield of rare events in the acquired heavy ion data a significant increase in luminosity is essential. In Run-7 RHIC achieved an average store luminosity of = 12 x 10{sup 26} cm{sup -2} s{sup -1} by operating with 103 bunches (out of 111 possible), and by squeezing to {beta}* = 0.85 m. This year, Run-10, we achieved = 20 x 10{sup 26} cm{sup -2} s{sup -1}, which put us an order of magnitude above the RHIC design luminosity. To reach these luminosity levels we decreased {beta}* to 0.75 m, operated with 111 bunches per ring, and reduced longitudinal and transverse emittances by means of bunched-beam stochastic cooling. In addition we introduced a lattice to suppress intra-beam scattering (IBS) in both RHIC rings, upgraded the RF control system, and separated transition crossing times in the two rings. We present an overview of the changes and the results of Run-10 performance.

  16. RHIC electron lenses upgrades

    SciTech Connect (OSTI)

    Gu, X.; Altinbas, Z.; Bruno, D.; Binello, S.; Costanzo, M.; Drees, A.; Fischer, W.; Gassner, D. M.; Hock, J.; Hock, K.; Harvey, M.; Luo, Y.; Marusic, A.; Mi, C.; Mernick, K.; Minty, M.; Michnoff, R.; Miller, T. A.; Pikin, A. I.; Robert-Demolaize, G.; Samms, T.; Shrey, T. C.; Schoefer, V.; Tan, Y.; Than, R.; Thieberger, P.; White, S. M.

    2015-05-03

    In the Relativistic Heavy Ion Collider (RHIC) 100 GeV polarized proton run in 2015, two electron lenses were used to partially compensate for the head-on beam-beam effect for the first time. Here, we describe the design of the current electron lens, detailing the hardware modifications made after the 2014 commissioning run with heavy ions. A new electron gun with 15-mm diameter cathode is characterized. The electron beam transverse profile was measured using a YAG screen and fitted with a Gaussian distribution. During operation, the overlap of the electron and proton beams was achieved using the electron backscattering detector in conjunction with an automated orbit control program.

  17. The Electron Beam Ion Source (EBIS)

    ScienceCinema (OSTI)

    Brookhaven Lab

    2010-01-08

    Brookhaven National Lab has successfully developed a new pre-injector system, called the Electron Beam Ion Source, for the Relativistic Heavy Ion Collider (RHIC) and NASA Space Radiation Laboratory science programs. The first of several planned improvemen

  18. RHIC low energy tests and initial operations

    SciTech Connect (OSTI)

    Satogata,T.; Ahrens, L.; Bai, M.; Brennan, J.M.; Bruno, D.; Butler, J.; Drees, A.; Fedotov, A.; Fischer, W.; Harvey, M.; Hayes, T.; Jappe, W.; Lee, R.C.; Mackay, W.W.; Malitsky, N.; Marr, G.; Michnoff, R.; Oerter, B.; Pozdeyev, E.; Roser, T.; Severino, F.; Smith, K.; Tepikian, S.; Tsoupas, N.

    2009-05-04

    Future Relativistic Heavy Ion Collider (RHIC) runs, including a portion of FY10 heavy ion operations, will explore collisions at center of mass energies of 5-50 GeV/n (GeV/nucleon). Operations at these energies is motivated by a search for the QCD phase transition critical point. The lowest end of this energy range is nearly a factor of four below the nominal RHIC injection center of mass energy of {radical} s = 20.8 GeV/n. There are several operational challenges in the RHIC low-energy regime, including harmonic number changes, small longitudinal acceptance, lowered magnet field quality, nonlinear orbit control, and luminosity monitoring. We report on the experience with some of these challenges during beam tests with gold in March 2008, including first RHIC operations at {radical}s = 9.18 GeV/n and first beam experience at {radical}s = 5 GeV/n.

  19. Azimuthal anisotropy in high-energy heavy-ion collisions at RHIC energies

    E-Print Network [OSTI]

    ShinIchi Esumi

    2004-05-19

    Directed and elliptic event anisotropy parameters measured in the experiments at relativistic heavy-ion collider are presented. The possible origin of the measured elliptic anisotropy parameter $v_2$ and its sensitivity to the early phase of the high-energy heavy-ion collisions are discussed.

  20. CRYSTAL COLLIMATION AT RHIC.

    SciTech Connect (OSTI)

    FLILLER,R.P.,III.DREES,A.GASSNER,D.HAMMONS,L.MCINTYRE,G.PEGGS,S.TRBOJEVIC,D.BIRYUKOV,V.CHESNOKOV,Y.TEREKHOV,V.

    2003-06-19

    Crystal Channeling occurs when an ion enters a crystal with a small angle with respect to the crystal planes. The electrostatic interaction between the incoming ion and the lattice causes the ion to follow the crystal planes. By mechanically bending a crystal, it is possible to use a crystal to deflect ions. One novel use of a bent crystal is to use it to channel beam halo particles into a collimator downstream. By deflecting the halo particles into a collimator with a crystal it may be possible to improve collimation efficiency as compared to a single collimator. A bent crystal is installed in the yellow ring of the Relativistic Heavy Ion Collider (RHIC). In this paper we discuss our experience with the crystal collimator, and compare our results to previous data, simulation, and theoretical prediction.

  1. Electron Ion Collider: The Next QCD Frontier - Understanding the glue that binds us all

    E-Print Network [OSTI]

    A. Accardi; J. L. Albacete; M. Anselmino; N. Armesto; E. C. Aschenauer; A. Bacchetta; D. Boer; W. K. Brooks; T. Burton; N. -B. Chang; W. -T. Deng; A. Deshpande; M. Diehl; A. Dumitru; R. Dupré; R. Ent; S. Fazio; H. Gao; V. Guzey; H. Hakobyan; Y. Hao; D. Hasch; R. Holt; T. Horn; M. Huang; A. Hutton; C. Hyde; J. Jalilian-Marian; S. Klein; B. Kopeliovich; Y. Kovchegov; K. Kumar; K. Kumeri?ki; M. A. C. Lamont; T. Lappi; J. -H. Lee; Y. Lee; E. M. Levin; F. -L. Lin; V. Litvinenko; T. W. Ludlam; C. Marquet; Z. -E. Meziani; R. McKeown; A. Metz; R. Milner; V. S. Morozov; A. H. Mueller; B. Müller; D. Müller; P. Nadel-Turonski; H. Paukkunen; A. Prokudin; V. Ptitsyn; X. Qian; J. -W. Qiu; M. Ramsey-Musolf; T. Roser; F. Sabatié; R. Sassot; G. Schnell; P. Schweitzer; E. Sichtermann; M. Stratmann; M. Strikman; M. Sullivan; S. Taneja; T. Toll; D. Trbojevic; T. Ullrich; R. Venugopalan; S. Vigdor; W. Vogelsang; C. Weiss; B. -W. Xiao; F. Yuan; Y. -H. Zhang; L. Zheng

    2014-11-30

    This White Paper presents the science case of an Electron-Ion Collider (EIC), focused on the structure and interactions of gluon-dominated matter, with the intent to articulate it to the broader nuclear science community. It was commissioned by the managements of Brookhaven National Laboratory (BNL) and Thomas Jefferson National Accelerator Facility (JLab) with the objective of presenting a summary of scientific opportunities and goals of the EIC as a follow-up to the 2007 NSAC Long Range plan. This document is a culmination of a community-wide effort in nuclear science following a series of workshops on EIC physics and, in particular, the focused ten-week program on "Gluons and quark sea at high energies" at the Institute for Nuclear Theory in Fall 2010. It contains a brief description of a few golden physics measurements along with accelerator and detector concepts required to achieve them, and it benefited from inputs from the users' communities of BNL and JLab. This White Paper offers the promise to propel the QCD science program in the U.S., established with the CEBAF accelerator at JLab and the RHIC collider at BNL, to the next QCD frontier.

  2. RHIC BBLR measurements in 2009

    SciTech Connect (OSTI)

    Calaga, R.; Robert-Demolaize, G.; Fischer, W.

    2010-05-23

    Long range beam-beam experiments were conducted during the Run 2009 in the Yellow and the Blue beams of the RHIC accelerator with DC wires. The effects of a long-range interaction with a DC wire on colliding and non-colliding bunches with the aid of beam losses, orbits, tunes were studied. Results from distance scans and an attempt to compensate a long-range interaction with a DC wire is presented. Two DC wires in the vertical plane were installed in the RHIC accelerator in 2006 with the aim of investigating long range (LR) beam-beam effects and a potential compensation. Extensive experiments were conducted focusing mainly on the effect of a wire on single ion beams from 2006-2009. A unique opportunity to compare the effect of the wire on colliding beams and compensation of a single LR beam-beam interaction were conducted in Run2009 with protons at 100 GeV. Due to aperture considerations for decreasing {beta}*, the Blue wire was removed during the shutdown after the Run2009 and the Yellow wire is foreseen to be removed in the near future. Therefore, these experiments serve as the final set of measurements for LR beam-beam with RHIC as a test bed. The relevant RHIC beam and lattice parameters are listed in Table 1 for the experiments in Run2009.

  3. CRYSTAL COLLIMATION AT RHIC.

    SciTech Connect (OSTI)

    FLILLER,III, R.P.; DREES,A.; GASSNER,D.; HAMMONS,L.; MCINTYRE,G.; PEGGS,S.; TRBOJEVIC,D.; BIRYUKOV,V.; CHESNKOV,Y.; TEREKHOV,V.

    2002-06-02

    For the year 2001 run, a bent crystal was installed in the yellow ring of the Relativistic Heavy Ion Collider (RHIC). The crystal forms the first stage of a two stage collimation system. By aligning the crystal to the beam, halo particles are channeled through the crystal and deflected into a copper scraper. The purpose is to reduce beam halo with greater efficiency than with a scraper alone. In this paper we present the first results from the use of the crystal collimator. We compare the crystal performance under various conditions, such as different particle species, and beta functions.

  4. Direct Photons at RHIC

    E-Print Network [OSTI]

    Klaus Reygers; for the PHENIX Collaboration

    2009-08-17

    A brief overview of direct-photon measurements in p+p and Au+Au collisions at sqrt(s_NN) = 200 GeV with the PHENIX experiment at the Relativistic Heavy Ion Collider (RHIC) is given. Direct-photon yields for pT > 4 GeV/c and photon-hadron azimuthal correlations were determined with the aid of an electromagnetic calorimeter. By detecting e+e- pairs from the internal conversion of virtual photons direct-photon yields were measured between 1 photons from a quark-gluon plasma (QGP) are expected to contribute significantly to the total direct-photon yield in this range.

  5. Heavy-ion performance of the LHC and future colliders

    E-Print Network [OSTI]

    AUTHOR|(SzGeCERN)696614; Jowett, John M.

    2015-10-09

    In 2008 the Large Hadron Collider (LHC) and its experiments started operation at the European Centre of Nuclear Research (CERN) in Geneva with the main aim of finding or excluding the Higgs boson. Only four years later, on the 4th of July 2012, the discovery of a Higgs-like particle was proven and first published by the two main experiments ATLAS and CMS. Even though proton–proton collisions are the main operation mode of the LHC, it also acts as an heavy-ion collider. Here, the term “heavy-ion collisions” refers to the collision between fully stripped nuclei. While the major hardware system of the LHC is compatible with heavy-ion operation, the beam dynamics and performance limits of ion beams are quite different from those of protons. Because of the higher mass and charge of the ions, beam dynamic effects like intra-beam scattering and radiation damping are stronger. Also the electromagnetic cross-sections in the collisions are larger, leading to significantly faster intensity decay and thus shorter l...

  6. Breakthrough: RHIC Explores Matter at the Dawn of Time

    ScienceCinema (OSTI)

    Paul Sorensen

    2013-07-19

    Physicist Paul Sorensen describes discoveries made at the Relativistic Heavy Ion Collider (RHIC), a particle accelerator at the U.S. Department of Energy's Brookhaven National Laboratory. At RHIC, scientists from around the world study what the universe may have looked like in the first microseconds after its birth, helping us to understand more about why the physical world works the way it does -- from the smallest particles to the largest stars.

  7. An Alternate Ring-Ring Design for eRHIC

    E-Print Network [OSTI]

    Zhang, Yuhong

    2015-01-01

    I present here a new ring-ring design of eRHIC, a polarized electron-ion collider based on RHIC at BNL. This alternate eRHIC design utilizes high repetition rate colliding beams and is likely able to deliver the performance to meet the requirements of the science program with low technical risk and modest accelerator R&D. The expected performance includes high luminosities over multiple collision points and a broad CM energy range with a maximum value up to 2x10^34 cm-2s-1 per detector, and polarization higher than 70% for the colliding electron and light ion beams. This new design calls for reuse of decommissioned facilities in the US, namely, the PEP-II high energy ring and one section of the SLAC warm linac as a full energy electron injector.

  8. OPTIMIZATION OF THE PARAMETERS IN THE RHIC SINGLE CRYSTAL HEAVY ION COLLIMATION.

    SciTech Connect (OSTI)

    BIRYUKOV,V.M.; CHESNOKOV,Y.A.; KOTOV,V.I.; TRBOJEVIC,D.; STEVENS,A.

    1999-03-29

    In the framework of the project to design and test a collimation system prototype using bent channeling crystal for cleaning of the RHIC heavy ion beam halo, we have studied the optimal length and bending angle of a silicon (110) single crystal proposed to be a primary element situated upstream of the traditional heavy amorphous collimator. Besides the matters of the channeling and collimation efficiency, we also looked into the impact the crystal may have on the non-channeled particles that go on circulating in the ring, so as to reduce the momentum offset of the particles scattered of the crystal.

  9. Crab Crossing Schemes and Studies for Electron Ion Collider

    SciTech Connect (OSTI)

    S. Ahmed, Y. Derbenev, V. Morozov, A. Castilla, G.A. Krafft, B. Yunn, Y. Zhang, J.R. Delayen

    2011-09-01

    This report shows our progress in crab crossing consideration for future electron-ion collider envisioned at JLab. In this design phase, we are evaluating two crabbing schemes viz., the deflecting and dispersive. The mathematical formulations and lattice design for these schemes are discussed in this paper. Numerical simulations involving particle tracking through a realistic deflecting RF cavity and optics illustrate the desired crab tilt of 25 mrad for 1.35 MV. Evolution of beam propagation are shown which provides the physical insight of the crabbing phenomenon.

  10. Universal Behavior of Charged Particle Production in Heavy Ion Collisions at RHIC Energies

    E-Print Network [OSTI]

    Peter Steinberg; PHOBOS Collaboration

    2002-10-17

    The PHOBOS experiment at RHIC has measured the multiplicity of primary charged particles as a function of centrality and pseudorapidity in Au+Au collisions at sqrt(s_NN) = 19.6, 130 and 200 GeV. Two kinds of universal behavior are observed in charged particle production in heavy ion collisions. The first is that forward particle production, over a range of energies, follows a universal limiting curve with a non-trivial centrality dependence. The second arises from comparisons with pp/pbar-p and e+e- data. N_tot/(N_part/2) in nuclear collisions at high energy scales with sqrt(s) in a similar way as N_tot in e+e- collisions and has a very weak centrality dependence. This feature may be related to a reduction in the leading particle effect due to the multiple collisions suffered per participant in heavy ion collisions.

  11. Off-momentum dynamic aperture for lattices in the RHIC heavy ion runs

    SciTech Connect (OSTI)

    Luo Y.; Bai, M.; Blaskiewicz, M.; Gu, X.; Fischer, W.; Marusic, A.; Roser, T.; Tepikian, S.; Zhang, S.

    2012-05-20

    To reduce transverse emittance growth rates from intrabeam scattering in the RHIC heavy ion runs, a lattice with an increased phase advance in the arc FODO cells was adopted in 2008-2011. During these runs, a large beam loss due to limited off-momentum dynamic aperture was observed during longitudinal RF re-bucketing and with transverse cooling. Based on the beam loss observations in the previous ion runs and the calculated off-momentum apertures, we decided to adopt the lattice used before 2008 for the 2012 U-U and Cu-Au runs. The observed beam decay and the measured momentum aperture in the 2012 U-U run are presented.

  12. HIGH PERFORMANCE EBIS FOR RHIC* , E. Beebe, O. Gould, A. Kponou, R. Lockey, A. Pikin, D. Raparia, J. Ritter, L. Snydstrup,

    E-Print Network [OSTI]

    Graaffs for injection of beams into the Booster synchrotron for RHIC and the NASA Space RadiationHIGH PERFORMANCE EBIS FOR RHIC* J. Alessi# , E. Beebe, O. Gould, A. Kponou, R. Lockey, A. Pikin, D being built at Brookhaven to provide increased capabilities for the Relativistic Heavy Ion Collider

  13. Elliptic flow fluctuations in heavy ion collisions at RHIC and the perfect liquid hypothesis

    E-Print Network [OSTI]

    Vogel, S; Bleicher, M; Vogel, Sascha; Torrieri, Giorgio; Bleicher, Marcus

    2007-01-01

    We analyse the recently measured $v_2$ fluctuation in the context of establishing the degree of fluidity of the matter produced in heavy ion collisions. We argue that flow observables within systems with a non-negligible mean free path should acquire a ``dynamical'' fluctuation, due to the random nature of each collision between the system's degrees of freedom. Because of this, $v_2$ fluctuations can be used to estimate the Knudsen number of the system produced at RHIC. To illustrate this quantitatively, we apply the UrQMD model, with scaled cross sections, to show that collisions at RHIC have a Knudsen number at least one order of magnitude above the expected value for an interacting hadron gas. Furthermore, we argue that the Knudsen number is also bound from above by the $v_2$ fluctuation data, because too large a Knudsen number would break the observed scaling of $v_2$ fluctuations due to the onset of turbulent flow. We propose, therefore that $v_2$ fluctuation measurements, together with an understanding ...

  14. Elliptic flow fluctuations in heavy ion collisions at RHIC and the perfect fluid hypothesis

    E-Print Network [OSTI]

    Sascha Vogel; Giorgio Torrieri; Marcus Bleicher

    2010-08-05

    We analyse the recently measured $v_2$ fluctuation in the context of establishing the degree of fluidity of the matter produced in heavy ion collisions. We argue that flow observables within systems with a non-negligible mean free path should acquire a "dynamical" fluctuation, due to the random nature of each collision between the system's degrees of freedom. Because of this, $v_2$ fluctuations can be used to estimate the Knudsen number of the system produced at RHIC. To illustrate this quantitatively, we apply the UrQMD model, with scaled cross sections, to show that collisions at RHIC have a Knudsen number at least one order of magnitude above the expected value for an interacting hadron gas. Furthermore, we argue that the Knudsen number is also bound from above by the $v_2$ fluctuation data, because too large a Knudsen number would break the observed scaling of $v_2$ fluctuations due to the onset of turbulent flow. We propose, therefore that $v_2$ fluctuation measurements, together with an understanding of the turbulent regime for relativistic hydrodynamics, will provide an upper as well as a lower limit for the Knudsen number.

  15. Opportunities for Drell-Yan Physics at RHIC

    SciTech Connect (OSTI)

    Aschenauer, E.; Bland, L.; Crawford, H.; Goto, Y.; Eyser, O.; Kang, Z.; Vossen, A.

    2011-05-24

    Drell-Yan (DY) physics gives the unique opportunity to study the parton structure of nucleons in an experimentally and theoretically clean way. With the availability of polarized proton-proton collisions and asymmetric d+Au collisions at the Relativistic Heavy Ion Collider (RHIC), we have the basic (and unique in the world) tools to address several fundamental questions in QCD, including the expected gluon saturation at low partonic momenta and the universality of transverse momentum dependent parton distribution functions. A Drell-Yan program at RHIC is tied closely to the core physics questions of a possible future electron-ion collider, eRHIC. The more than 80 participants of this workshop focused on recent progress in these areas by both theory and experiment, trying to address imminent questions for the near and mid-term future.

  16. Electromagnetic Probes at RHIC-II

    E-Print Network [OSTI]

    G. David; R. Rapp; Z. Xu

    2008-04-25

    We summarize how future measurements of electromagnetic (e.m.) probes at the Relativistic Heavy Ion Collider (RHIC), in connection with theoretical analysis, can advance our understanding of strongly interacting matter at high energy densities and temperatures. After a brief survey of the important role that e.m. probes data have played at the Super Proton Synchrotron (SPS, CERN) and RHIC to date, we identify key physics objectives and observables that remain to be addressed to characterize the (strongly interacting) Quark-Gluon Plasma (sQGP) and associated transition properties at RHIC. These include medium modifications of vector mesons via low-mass dileptons, a temperature measurement of the hot phases via continuum radiation, as well as gamma-gamma correlations to characterize early source sizes. We outline strategies to establish microscopic matter and transition properties such as the number of degrees of freedom in the sQGP, the origin of the hadron masses and manifestations of chiral symmetry restoration, which will require accompanying but rather well-defined advances in theory. Increased experimental precision, order of magnitude higher statistics than currently achievable, as well as a detailed scan of colliding species and energies are then mandatory to achieve sufficient discrimination power in theoretical interpretations. This increased precision can be achieved with hardware upgrades to the large RHIC detectors (PHENIX and STAR) along with at least a factor of ten as increase in luminosity over the next few years as envisioned for RHIC-II.

  17. Design studies for the next generation electron ion colliders

    SciTech Connect (OSTI)

    Sayed, Hisham Kamal; Bogacz, Slawomir A.; Krafft, Geoffrey A.

    2014-04-01

    The next generation Electron Ion Collider (EIC) at Thomas Jefferson National Accelerator Facility (JLAB) utilizes a figure-8 shaped ion and electron rings. EIC has the ability to preserve the ion polarization during acceleration, where the electron ring matches in footprint with a figure-8 ion ring. The electron ring is designed to deliver a highly polarized high luminous electron beam at interaction point (IP). The main challenges of the electron ring design are the chromaticity compensation and maintaining high beam polarization of 70% at all energies 3–11 GeV without introducing transverse orbital coupling before the IP. The very demanding detector design limits the minimum distance between the final focus quadrupole and the interaction point to 3.5 m which results in a large ? function inside the final focus quadrupoles leading to increased beam chromaticity. In this paper, we present a novel chromaticity compensation scheme that mitigates IP chromaticity by a compact chromaticity compensation section with multipole magnet components. In addition, a set of spin rotators are utilized to manipulate the polarization vector of the electron beam in order to preserve the beam polarization. The spin rotator solenoids introduce undesired coupling between the horizontal and vertical betatron motion of the beam. We introduce a compact and modular orbit decoupling insert that can fit in the limited space of the straight section in the figure-8 ring. We show a numerical study of the figure-8 ring design with the compact straight section, which includes the interaction region, chromaticity compensation section, and the spin rotators, the figure-8 design performance is evaluated with particle tracking.

  18. Transfer of polarized 3He ions in the AtR beam transfer line

    SciTech Connect (OSTI)

    Tsoupas N.; MacKay, W.W.; Meot, F.; Roser, T.; Trbojevic, D.

    2012-05-20

    In addition to collisions of electrons with various unpolarized ion species as well as polarized protons, the proposed electron-hadron collider (eRHIC) will facilitate the collisions of electrons with polarized {sup 3}He ions. The AGS is the last acceleration stage, before injection into one of the RHIC's collider ring for final acceleration. The AtR (AGS to RHIC) transfer line will be utilized to transport the polarized {sup 3}He ions from AGS into one of the RHIC's collider rings. Some of the peculiarities of the AtR line's layout (simultaneous horizontal and vertical bends) may degrade the matching of the stable spin direction of the AtR line with that of RHIC's. In this paper we discuss possible simple modifications of the AtR line to accomplish a perfect matching of the stable spin direction of the injected {sup 3}He beam with the stable spin direction at the injection point of RHIC.

  19. THE RHIC INJECTOR ACCELERATORS CONFIGURATIONS, AND PERFORMANCE FOR THE RHIC 2003 AU - D PHYSICS RUN.

    SciTech Connect (OSTI)

    Ahrens, L; Benjamin, J; Blaskiewicz, M; Brennan, J M; Brown, K A; Carlson, K A; Delong, J; D' Ottavio, T; Frak, B; Gardner, C J; Glenn, J W; Harvey, M; Hayes, T; Hseuh, H- C; Ingrassia, P; Lowenstein, D; Mackay, W; Marr, G; Morris, J; Roser, T; Satogata, T; Smith, G; Smith, K S; Steski, D; Tsoupas, N; Thieberger, P; Zeno, K

    2003-05-12

    The RHIC 2003 Physics Run [1] required collisions between gold ions and deuterons. The injector necessarily had to deliver adequate quality (transverse and longitudinal emittance) and quantity of both species. For gold this was a continuing evolution from past work [2]. For deuterons it was new territory. For the filling of the RHIC the injector not only had to deliver quality beams but also had to switch between these species quickly. This paper details the collider requirements and our success in meeting these. Some details of the configurations employed are given.

  20. Fourth workshop on experiments and detectors for a relativistic heavy ion collider

    SciTech Connect (OSTI)

    Fatyga, M.; Moskowitz, B.

    1990-01-01

    This report contains papers on the following topics: physics at RHIC; flavor flow from quark-gluon plasma; space-time quark-gluon cascade; jets in relativistic heavy ion collisions; parton distributions in hard nuclear collisions; experimental working groups, two-arm electron/photon spectrometer collaboration; total and elastic pp cross sections; a 4{pi} tracking TPC magnetic spectrometer; hadron spectroscopy; efficiency and background simulations for J/{psi} detection in the RHIC dimuon experiment; the collision regions beam crossing geometries; Monte Carlo simulations of interactions and detectors; proton-nucleus interactions; the physics of strong electromagnetic fields in collisions of relativistic heavy ions; a real time expert system for experimental high energy/nuclear physics; the development of silicon multiplicity detectors; a pad readout detector for CRID/tracking; RHIC TPC R D progress and goals; development of analog memories for RHIC detector front-end electronic systems; calorimeter/absorber optimization for a RHIC dimuon experiment; construction of a highly segmented high resolution TOF system; progress report on a fast, particle-identifying trigger based on ring-imaging and highly integrated electronics for a TPC detector.

  1. Design of Electron and Ion Crabbing Cavities for an Electron-Ion Collider

    SciTech Connect (OSTI)

    Alejandro Castilla Loeza, Geoffrey Krafft, Jean Delayen

    2012-07-01

    Beyond the 12 GeV upgrade at the Jefferson Lab a Medium Energy Electron-Ion Collider (MEIC) has been considered. In order to achieve the desired high luminosities at the Interaction Points (IP), the use of crabbing cavities is under study. In this work, we will present to-date designs of superconducting cavities, considered for crabbing both ion and electron bunches. A discussion of properties such as peak surface fields and higher-order mode separation will be presented. Keywords: super conducting, deflecting cavity, crab cavity.

  2. Workshop on the RHIC performance

    SciTech Connect (OSTI)

    Khiari, F.; Milutinovic, J.; Ratti, A.; Rhoades-Brown, M.J. (eds.)

    1988-07-01

    The most recent conceptual design manual for the Relativistic Heavy Ion Collider (RHIC) at Brookhaven was published in May 1986 (BNL 51932). The purpose of this workshop was to review the design specifications in this RHIC reference manual, and to discuss in detail possible improvements in machine performance by addressing four main areas. These areas are beam-beam interactions, stochastic cooling, rf and bunch instabilities. The contents of this proceedings are as follows. Following an overview of the workshop, in which the motivation and goals are discussed in detail, transcripts of the first day talks are given. Many of these transcripts are copies of the original transparencies presented at the meeting. The following four sections contain contributed papers, that resulted from discussions at the workshop within each of the four working groups. In addition, there is a group summary for each of the four working groups at the beginning of each section. Finally, a list of participants is given.

  3. Strange Content of Baryons at RHIC

    E-Print Network [OSTI]

    B. Hippolyte; for the STAR Collaboration

    2003-06-14

    Via the study of strange particle production within the STAR experiment, we try to address the surprising amount of baryon transport at the Relativistic Heavy Ion Collider (RHIC). We report here preliminary results showing that, at mid-rapidity and for the top energy of RHIC, the number of created baryons exceeds the number transported from the colliding nuclei. However, thanks to the large acceptance of the experimental setup, one could expect to observe the transition between the ``soft'' regime (low transverse momentum -$\\pt$- region corresponding to a bulk of hot and dense matter hadronizing) and the perturbative one (higher $\\pt$ region) where the fragmentation of incoming partons is supposed to dominate hadron production.}

  4. A STUDY OF RHIC CRYSTAL COLLIMATION.

    SciTech Connect (OSTI)

    TRBOJEVIC,D.

    1998-06-26

    The Relativistic Heavy Ion Collider (RHIC) will experience increasing longitudinal and transverse heavy ion emittances, mostly due to intra-beam scattering (IBS). The experiments in RHIC are expected to not only have reduced luminosities due to IBS but also background caused by beam halo. Primary betatron collimators will be used to remove the large amplitude particles. The efficiency of the primary collimator in RHIC strongly depends on the alignment of the jaws which needs to be within about ten micro-radians for the optimum conditions. As proposed by V. Biryukov [1] bent crystals could be used to improve the efficiency of an existing collimation system by installing them upstream of the collimator jaws. Bent crystals have been successfully used in SPS, Protvino and Fermilab for extraction of the beam particles channeled through them. This study examines possible improvements of the primary collimator system for heavy ions at RHIC by use of bent crystals. Bent crystals will reduce the collimator jaws alignment requirement and will increase collimator efficiency thereby reducing detector background.

  5. A study of RHIC crystal collimation

    SciTech Connect (OSTI)

    Trbojevic, D.; Harrison, M.; Parker, B.; Thompson, P.; Stevens, A.; Biryukov, V.; Mokhov, N.; Drozhdin, A.

    1998-08-01

    The Relativistic Heavy Ion Collider (RHIC) will experience increasing longitudinal and transverse heavy ion emittances, mostly due to intra-beam scattering (IBS). The experiments in RHIC are expected to not only have reduced luminosities due to IBS but also background caused by beam halo. Primary betatron collimators will be used to remove the large amplitude particles. The efficiency of the primary collimator in RHIC strongly depends on the alignment of the jaws which needs to be within about ten micro-radians for the optimum conditions. As proposed by V. biryukov bent crystals could be used to improve the efficiency of an existing collimation system by installing them upstream of the collimator jaws. Bent crystals have been successfully used in SPS, Protvino and Fermilab for extraction of the beam particles channeled through them. This study examines possible improvements of the primary collimator system for heavy ions at RHIC by use of bent crystals. Bent crystals will reduce the collimator jaws alignment requirement and will increase collimator efficiency thereby reducing detector background.

  6. A study of RHIC crystal collimation

    E-Print Network [OSTI]

    D. Trbojevic; V. M. Biryukov; M. Harrison; B. Parker; P. Thompson; A. Stevens; N. Mokhov; A. Drozhdin

    2001-11-07

    The Relativistic Heavy Ion Collider (RHIC) will experience increasing longitudinal and transverse heavy ion emittances, mostly due to intra-beam scattering (IBS). The experiments in RHIC are expected to not only have reduced luminosities due to IBS but also an unwanted beam halo. Primary betatron collimators will be used to remove the large amplitude particles. The efficiency of the primary collimator in RHIC depends very much on the alignment of the jaws which needs to be within few micro-radians for the best conditions. As proposed by V. Biryukov bent crystals could be used to improve the efficiency of an existing collimation system by installing them upstream of the collimator jaws. Bent crystals have been successfully used in SPS, Protvino and Fermilab for extraction of the beam particles channeled through them. This study examines possible improvements of the primary collimator system for heavy ions at RHIC by use of bent crystals. Bent crystals will reduce the collimator jaws alignment requirement and will increase collimator efficiency thereby reducing detector background.

  7. Effect of the electron lenses on the RHIC proton beam closed orbit

    SciTech Connect (OSTI)

    Gu, X.; Luo, Y.; Pikin, A.; Okamura, M.; Fischer, W.; Montag, C.; Gupta, R.; Hock, J.; Jain, A.; Raparia, D.

    2011-02-01

    We are designing two electron lenses (E-lens) to compensate for the large beam-beam tune spread from proton-proton interactions at IP6 and IP8 in the Relativistic Heavy Ion Collider (RHIC). They will be installed at RHIC IR10. The transverse fields of the E-lenses bending solenoids and the fringe field of the main solenoids will shift the proton beam. We calculate the transverse kicks that the proton beam receives in the electron lens via Opera. Then, after incorporating the simplified E-lens lattice in the RHIC lattice, we obtain the closed orbit effect with the Simtrack Code.

  8. High-p_T Pion Production in Heavy-Ion Collisions at RHIC energies

    E-Print Network [OSTI]

    G. G. Barnafoldi; P. Levai; G. Papp; G. Fai; Y. Zhang

    2003-01-15

    Perturbative QCD results on pion production are presented in proton-proton, proton-nucleus and nucleus-nucleus collisions from CERN SPS up to RHIC energy. A K_{jet}(s, p_T, Q) factor obtained from jet production is applied to perform next-to-leading order calculations. Using the intrinsic transverse momentum (k_T) we determined transverse momentum spectra for pions in wide energy region. We have investigated nuclear multiscattering and the Cronin effect at RHIC energies.

  9. RHIC Polarized proton operation

    SciTech Connect (OSTI)

    Huang, H.; Ahrens, L.; Alekseev, I.G.; Aschenauer, E.; Atoian, G.; Bai, M.; Bazilevsky, A.; Blaskiewicz, M.; Brennan, J.M.; Brown, K.A.; Bruno, D.; Connolly, R.; Dion, A.; D'Ottavio, T.; Drees, K.A.; Fischer, W.; Gardner, C.; Glenn, J.W.; Gu, X.; Harvey, M.; Hayes, T.; Hoff, L.; Hulsart, R.L.; Laster, J.; Liu, C.; Luo, Y.; MacKay, W.W.; Makdisi, Y.; Marr, G.J.; Marusic, A.; Meot, F.; Mernick, K.; Michnoff, R,; Minty, M.; Montag, C.; Morris, J.; Nemesure, S.; Poblaguev, A.; Ptitsyn, V.; Ranjibar, V.; Robert-Demolaize, G.; Roser, T.; J.; Severino, F.; Schmidke, B.; Schoefer, V.; Severino, F.; Smirnov, D.; Smith, K.; Steski, D.; Svirida, D.; Tepikian, S.; Trbojevic, D.; Tsoupas, N.; Tuozzolo, J. Wang, G.; Wilinski, M.; Yip, K.; Zaltsman, A.; Zelenski, A.; Zeno, K.; Zhang, S.Y.

    2011-03-28

    The Relativistic Heavy Ion Collider (RHIC) operation as the polarized proton collider presents unique challenges since both luminosity(L) and spin polarization(P) are important. With longitudinally polarized beams at the experiments, the figure of merit is LP{sup 4}. A lot of upgrades and modifications have been made since last polarized proton operation. A 9 MHz rf system is installed to improve longitudinal match at injection and to increase luminosity. The beam dump was upgraded to increase bunch intensity. A vertical survey of RHIC was performed before the run to get better magnet alignment. The orbit control is also improved this year. Additional efforts are put in to improve source polarization and AGS polarization transfer efficiency. To preserve polarization on the ramp, a new working point is chosen such that the vertical tune is near a third order resonance. The overview of the changes and the operation results are presented in this paper. Siberian snakes are essential tools to preserve polarization when accelerating polarized beams to higher energy. At the same time, the higher order resonances still can cause polarization loss. As seen in RHIC, the betatron tune has to be carefully set and maintained on the ramp and during the store to avoid polarization loss. In addition, the orbit control is also critical to preserve polarization. The higher polarization during this run comes from several improvements over last run. First we have a much better orbit on the ramp. The orbit feedback brings down the vertical rms orbit error to 0.1mm, much better than the 0.5mm last run. With correct BPM offset and vertical realignment, this rms orbit error is indeed small. Second, the jump quads in the AGS improved input polarization for RHIC. Third, the vertical tune was pushed further away from 7/10 snake resonance. The tune feedback maintained the tune at the desired value through the ramp. To calibrate the analyzing power of RHIC polarimeters at any energy above injection, the polarized hydrogen jet target runs for every fill with both beams. Based on the known analyzing power, there is very little polarization loss between injection and 100 GeV. An alternative way is to measure the asymmetry at 100 GeV followed by ramping up to 250 GeV and back down to 100 GeV and then to measure the asymmetry again at 100 GeV. If the asymmetry after the down ramp is similar to the measurement before the up ramp, polarization was also preserved during the ramp to 250 GeV. The analyzing power at storage energy can then be extracted from the asymmetries measured at 100 GeV and 250 GeV. The tune and orbit feedbacks are essential for the down ramp to be possible. The polarized proton operation is still going on. We will push bunch intensity higher until reaching the beam-beam limit. The even higher intensity will have to wait for the electron lenses to compensate the beam-beam effect. To understand the details of spin dynamics in RHIC with two snakes, spin simulation with the real magnet fields have been developed recently. The study will provide guidance for possible polarization loss schemes. Further polarization gain will requires a polarized source upgrade; more careful setup jump quads in the AGS to get full benefit; and control emittance in the whole accelerator chain.

  10. Strongly interacting matter at RHIC: experimental highlights

    E-Print Network [OSTI]

    V. A. Okorokov

    2014-10-27

    Recent experimental results obtained at the Relativistic Heavy-Ion Collider (RHIC) will be discussed. Investigations of different nucleus-nucleus collisions in recent years focus on two main tasks, namely, the detailed study of sQGP properties and the exploration of the QCD phase diagram. Results at top RHIC energy provide important information about event shapes as well as transport and thermodynamic properties of the hot medium for various flavors. Heavy-ion collisions are a unique tool for the study of topological properties of theory. Experimental results obtained for discrete QCD symmetries at finite temperatures are discussed. These results confirm indirectly the topologically non-trivial structure of the QCD vacuum. Most results obtained during phase-I of the RHIC beam energy scan (BES) program show smooth behavior vs initial energy. However, certain results suggest the transition in the domain of dominance of hadronic degrees of freedom at center-of-mass energies between 10-20 GeV. Future developments and more precise studies of features of the QCD phase diagram in the framework of phase-II of RHIC BES will be briefly discussed.

  11. RESEARCH PLAN FOR SPIN PHYSICS AT RHIC.

    SciTech Connect (OSTI)

    AIDALA, C.; BUNCE, G.; ET AL.

    2005-02-01

    In this report we present the research plan for the RHIC spin program. The report covers (1) the science of the RHIC spin program in a world-wide context; (2) the collider performance requirements for the RHIC spin program; (3) the detector upgrades required, including timelines; (4) time evolution of the spin program.

  12. Relativistic Heavy Ion Collider (RHIC) | U.S. DOE Office of Science (SC)

    Office of Science (SC) Website

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power AdministrationRobust,Field-effectWorkingLosThe 26thI D-Nicholas

  13. The Unified Hydrodynamics and the Pseudorapidity Distributions in Heavy Ion Collisions at BNL-RHIC and CERN-LHC Energies

    E-Print Network [OSTI]

    Jiang, Z J; Ma, K; Zhang, H L

    2015-01-01

    The charged particles produced in nucleus-nucleus collisions are divided into two parts. One is from the hot and dense matter created in collisions. The other is from leading particles. The hot and dense matter is assumed to expand according to unified hydrodynamics and freezes out into charged particles from a space-like hypersurface with a fixed proper time of Tau_FO.The leading particles are conventionally taken as the particles which inherit the quantum numbers of colliding nucleons and carry off most of incident energy. The rapidity distributions of the charged particles from these two parts are formulated analytically, and a comparison is made between the theoretical results and the experimental measurements performed in Au-Au and Pb-Pb collisions at the respective BNL-RHIC and CERN-LHC energies. The theoretical results are well consistent with experimental data.

  14. Design of the Proposed Low Energy Ion Collider Ring at Jefferson Lab

    SciTech Connect (OSTI)

    Nissen, Edward W.; Lin, Fanglei; Morozov, Vasiliy; Zhang, Yuhong

    2013-06-01

    The polarized Medium energy Electron-Ion Collider (MEIC) envisioned at Jefferson Lab will cover a range of center-of-mass energies up to 65 GeV. The present MEIC design could also allow the accommodation of low energy electron-ion collisions (LEIC) for additional science reach. This paper presents the first design of the low energy ion collider ring which is converted from the large ion booster of MEIC. It can reach up to 25 GeV energy for protons and equivalent ion energies of the same magnetic rigidity. An interaction region and an electron cooler designed for MEIC are integrated into the low energy collider ring, in addition to other required new elements including crab cavities and ion spin rotators, for later reuse in MEIC itself. A pair of vertical chicanes which brings the low energy ion beams to the plane of the electron ring and back to the low energy ion ring are also part of the design.

  15. Electron-Ion Collider - taking us to the next QCD frontier

    E-Print Network [OSTI]

    Jian-Wei Qiu

    2014-12-08

    In this talk, I demonstrate that the proposed Electron-Ion Collider (EIC) will be an ideal and unique future facility to address many overarching questions about QCD and strong interaction physics at one place. The EIC will be the world's first polarized electron-proton (and light ion), as well as the first electron-nucleus collider at flexible collision energies. With its high luminosity and beam polarization, the EIC distinguishes itself from HERA and the other fixed target electron-hadron facilities around the world. The EIC is capable of taking us to the next QCD frontier to explore the glue that binds us all.

  16. Long-range and head-on beam-beam compensation studies in RHIC with lessons for the LHC

    E-Print Network [OSTI]

    Fischer, W.

    2009-01-01

    Normalized luminosity in the eRHIC ring-ring version as ation [64]. collider eRHIC [64]. From these simulation a

  17. Science Requirements and Conceptual Design for a Polarized Medium Energy Electron-Ion Collider at Jlab

    SciTech Connect (OSTI)

    Abeyratne, S; Ahmed, S; Barber, D; Bisognano, J; Bogacz, A; Castilla, A; Chevtsov, P; Corneliussen, S; Deconinck, W; Degtiarenko, P; Delayen, J; Derbenev, Ya; DeSilva, S; Douglas, D; Dudnikov, V; Ent, R; Erdelyi, B; Evtushenko, P; Fujii, Yu; Filatov, Yury; Gaskell, D; Geng, R; Guzey, V; Horn, T; Hutton, A; Hyde, C; Johnson, R; Kim, Y; Klein, F; Kondratenko, A; Kondratenko, M; Krafft, G; Li, R; Lin, F; Manikonda, S; Marhauser, F; McKeown, R; Morozov, V; Dadel-Turonski, P; Nissen, E; Ostroumov, P; Pivi, M; Pilat, F; Poelker, M; Prokudin, A; Rimmer, R; Satogata, T; Sayed, H; Spata, M; Sullivan, M; Tennant, C; Terzic, B; Tiefenback, M; Wang, M; Wang, S; Weiss, C; Yunn, B

    2012-08-01

    Researchers have envisioned an electron-ion collider with ion species up to heavy ions, high polarization of electrons and light ions, and a well-matched center-of-mass energy range as an ideal gluon microscope to explore new frontiers of nuclear science. In its most recent Long Range Plan, the Nuclear Science Advisory Committee (NSAC) of the US Department of Energy and the National Science Foundation endorsed such a collider in the form of a 'half-recommendation.' As a response to this science need, Jefferson Lab and its user community have been engaged in feasibility studies of a medium energy polarized electron-ion collider (MEIC), cost-effectively utilizing Jefferson Lab's already existing Continuous Electron Beam Accelerator Facility (CEBAF). In close collaboration, this community of nuclear physicists and accelerator scientists has rigorously explored the science case and design concept for this envisioned grand instrument of science. An electron-ion collider embodies the vision of reaching the next frontier in Quantum Chromodynamics - understanding the behavior of hadrons as complex bound states of quarks and gluons. Whereas the 12 GeV Upgrade of CEBAF will map the valence-quark components of the nucleon and nuclear wave functions in detail, an electron-ion collider will determine the largely unknown role sea quarks play and for the first time study the glue that binds all atomic nuclei. The MEIC will allow nuclear scientists to map the spin and spatial structure of quarks and gluons in nucleons, to discover the collective effects of gluons in nuclei, and to understand the emergence of hadrons from quarks and gluons. The proposed electron-ion collider at Jefferson Lab will collide a highly polarized electron beam originating from the CEBAF recirculating superconducting radiofrequency (SRF) linear accelerator (linac) with highly polarized light-ion beams or unpolarized light- to heavy-ion beams from a new ion accelerator and storage complex. Since the very beginning, the design studies at Jefferson Lab have focused on achieving high collider performance, particularly ultrahigh luminosities up to 10{sup 34} cm{sup -2}s{sup -1} per detector with large acceptance, while maintaining high polarization for both the electron and light-ion beams. These are the two key performance requirements of a future electron-ion collider facility as articulated by the NSAC Long Range Plan. In MEIC, a new ion complex is designed specifically to deliver ion beams that match the high bunch repetition and highly polarized electron beam from CEBAF. During the last two years, both development of the science case and optimization of the machine design point toward a medium-energy electron-ion collider as the topmost goal for Jefferson Lab. The MEIC, with relatively compact collider rings, can deliver a luminosity above 10{sup 34} cm{sup -2}s{sup -1} at a center-of-mass energy up to 65 GeV. It offers an electron energy up to 11 GeV, a proton energy up to 100 GeV, and corresponding energies per nucleon for heavy ions with the same magnetic rigidity. This design choice balances the scope of the science program, collider capabilities, accelerator technology innovation, and total project cost. An energy upgrade could be implemented in the future by adding two large collider rings housed in another large tunnel to push the center-of-mass energy up to or exceeding 140 GeV. After careful consideration of an alternative electron energy recovery linac on ion storage ring approach, a ring-ring collider scenario at high bunch repetition frequency was found to offer fully competitive performance while eliminating the uncertainties of challenging R&D on ampere-class polarized electron sources and many-pass energy-recovery linacs (ERLs). The essential new elements of an MEIC facility at Jefferson Lab are an electron storage ring and an entirely new, modern ion acceleration and storage complex. For the high-current electron collider ring, the upgraded 12 GeV CEBAF SRF linac will serve as a full-energy injector, and, if needed, provide top

  18. NEW RESULTS FROM CRYSTAL COLLIMATION AT RHIC.

    SciTech Connect (OSTI)

    FLILLER,R.P.,IIIDREES,A.GASSNER,D.HAMMONS,L.MCINTYRE,G.PEGGS,S.TRBOJEVIC,D.BIRYUKOV,V.CHESNOKOV,Y.TEREKHOV,V.

    2003-05-12

    In this paper, we discuss new results from the use of the crystal collimator from the 2003 run. The yellow ring of the Relativistic Heavy Ion Collider (RHIC) has a bent crystal collimator. By properly aligning the crystal to the beam halo, particles entering the crystal are deflected away from the beam and intercepted downstream in a copper scraper. The purpose of a bent crystal is to improve the collimation efficiency as compared to a scraper alone. We compare these results to previous data, simulation, and theoretical predictions.

  19. Recent Triplet Vibration Studies in RHIC

    SciTech Connect (OSTI)

    Thieberger, P.; Bonati, R.; Corbin, G.; Jain, A.; Minty, M.; McIntyre, G.; Montag, C.; Muratore, J.; Schultheiss, C.; Seberg, S.; Tuozzolo, J.

    2010-05-23

    We report on recent developments for mitigating vibrations of the quadrupole magnets near the interaction regions of the Relativistic Heavy Ion Collider (RHIC). High precision accelerometers, geophones, and a laser vibrometer were installed around one of the two interaction points to characterize the frequencies of the mechanical motion. In addition actuators were mounted directly on the quadrupole cryostats. Using as input the locally measured motion, dynamic damping of the mechanical vibrations has been demonstrated. In this report we present these measurements and measurements of the beam response. Future options for compensating the vibrations are discussed.

  20. Opportunities for Polarized He-3 in RHIC and EIC

    SciTech Connect (OSTI)

    Aschenauer E.; Deshpande, A.; Fischer, W.; Derbenev, S.; Milner, R.; Roser, T.; Zelenski, A.

    2011-10-01

    The workshop on opportunities for polarized He-3 in RHIC and EIC was targeted at finding practical ways of implementing and using polarized He-3 beams. Polarized He-3 beams will provide the unique opportunity for first measurements, i.e, to a full quark flavor separation measuring single spin asymmetries for p{sup +}, p{sup -} and p{sup 0} in hadron-hadron collisions. In electron ion collisions the combination of data recorded with polarized electron proton/He-3 beams allows to determine the quark flavor separated helicity and transverse momentum distributions. The workshop had sessions on polarized He-3 sources, the physics of colliding polarized He-3 beams, polarimetry, and beam acceleration in the AGS Booster, AGS, RHIC, and ELIC. The material presented at the workshop will allow making plans for the implementation of polarized He-3 beams in RHIC.

  1. From many body wee partons dynamics to perfect fluid: a standard model for heavy ion collisions

    SciTech Connect (OSTI)

    Venugopalan, R.

    2010-07-22

    We discuss a standard model of heavy ion collisions that has emerged both from experimental results of the RHIC program and associated theoretical developments. We comment briefly on the impact of early results of the LHC program on this picture. We consider how this standard model of heavy ion collisions could be solidified or falsified in future experiments at RHIC, the LHC and a future Electro-Ion Collider.

  2. Copper vs. Copper at the Relativistic Heavy Ion Collider (2005)

    SciTech Connect (OSTI)

    Brookhaven Lab - Fulvia Pilat

    2009-06-09

    To investigate a new form of matter not seen since the Big Bang, scientists are using a new experimental probe: collisions between two beams of copper ions. The use of intermediate size nuclei is expected to result in intermediate energy density - not as

  3. Copper vs. Copper at the Relativistic Heavy Ion Collider (2005)

    ScienceCinema (OSTI)

    Brookhaven Lab - Fulvia Pilat

    2010-01-08

    To investigate a new form of matter not seen since the Big Bang, scientists are using a new experimental probe: collisions between two beams of copper ions. The use of intermediate size nuclei is expected to result in intermediate energy density - not as

  4. eRHIC Detector Design Studies - Implications and Constraints on the ep (A) Interaction-Region Design

    E-Print Network [OSTI]

    Surrow, Bernd; Pasukonis, Jurgis

    2005-01-01

    An electron-proton/ion collider facility (eRHIC) is under consideration at Brookhaven National Laboratory (BNL). Such a new facility will require the design and construction of a new optimized detector profiting from the world's first ep collider facility HERA at DESY. The detailed design is closely coupled to the design of the interaction region and thus to the machine development work in general. Implications and constraints on the ep(A) interaction-region design will be discussed.

  5. Gatling gun: high average polarized current injector for eRHIC

    SciTech Connect (OSTI)

    Litvinenko, V.N.

    2010-01-01

    This idea was originally developed in 2001 for, at that time, an ERL-based (and later recirculating-ring) electron-ion collider at JLab. Naturally the same idea is applicable for any gun requiring current exceeding capability of a single cathode. ERL-based eRHIC is one of such cases. This note related to eRHIC was prepared at Duke University in February 2003. In many case photo-injectors can have a limited average current - it is especially true about polarized photo-guns. It is know that e-RHIC requires average polarized electron current well above currently demonstrated by photo-injectors - hence combining currents from multiple guns is can be useful option for eRHIC.

  6. RHIC low-energy challenges and plans

    SciTech Connect (OSTI)

    Satogata,T.; Ahrens, L.; Bai, M.; Brennan, J.M.; Bruno, D.; Butler, J.; Drees, A.; Fedotov, A.; Fischer, W.; Harvey, M.; Hayes, T.; Jappe, W.; Lee, R.C.; MacKay, W.W.; Malitsky, N.; Marr, G.; Michnoff, R.; Oerter, B.; Pozdeyev, E.; Roser, T.; Schoefer, V.; Severino, F.; Smith, K.; Tepikian, S.; Tsoupas, N.

    2009-06-08

    Future Relativistic Heavy Ion Collider (RHIC) runs, including a portion of FY10 heavy ion operations, will explore collisions at center of mass energies of 5-50 GeV/n (GeV/nucleon). Operations at these energies is motivated by the search for a possible QCD phase transition critical point. The lowest end of this energy range is nearly a factor of four below the nominal RHIC injection center of mass energy {radical}s = 19.6 GeV/n. There are several operational challenges in the RHIC low-energy regime, including harmonic number changes, small longitudinal acceptance, lowered magnet field quality, nonlinear orbit control, and luminosity monitoring. We report on the experience with these challenges during beam tests with gold beams in March 2008. This includes first operations at {radical}s = 9.18 GeV/n, first beam experience at {radical}s = 5 GeV/n, and luminosity projections for near-term operations.

  7. PHENIX Conceptual Design Report. An experiment to be performed at the Brookhaven National Laboratory Relativistic Heavy Ion Collider

    SciTech Connect (OSTI)

    Nagamiya, Shoji; Aronson, Samuel H.; Young, Glenn R.; Paffrath, Leo

    1993-01-29

    The PHENIX Conceptual Design Report (CDR) describes the detector design of the PHENIX experiment for Day-1 operation at the Relativistic Heavy Ion Collider (RHIC). The CDR presents the physics capabilities, technical details, cost estimate, construction schedule, funding profile, management structure, and possible upgrade paths of the PHENIX experiment. The primary goals of the PHENIX experiment are to detect the quark-gluon plasma (QGP) and to measure its properties. Many of the potential signatures for the QGP are measured as a function of a well-defined common variable to see if any or all of these signatures show a simultaneous anomaly due to the formation of the QGP. In addition, basic quantum chromodynamics phenomena, collision dynamics, and thermodynamic features of the initial states of the collision are studied. To achieve these goals, the PHENIX experiment measures lepton pairs (dielectrons and dimuons) to study various properties of vector mesons, such as the mass, the width, and the degree of yield suppression due to the formation of the QGP. The effect of thermal radiation on the continuum is studied in different regions of rapidity and mass. The e{mu} coincidence is measured to study charm production, and aids in understanding the shape of the continuum dilepton spectrum. Photons are measured to study direct emission of single photons and to study {pi}{sup 0} and {eta} production. Charged hadrons are identified to study the spectrum shape, production of antinuclei, the {phi} meson (via K{sup +}K{sup {minus}} decay), jets, and two-boson correlations. The measurements are made down to small cross sections to allow the study of high p{sub T} spectra, and J/{psi} and {Upsilon} production. The PHENIX collaboration consists of over 300 scientists, engineers, and graduate students from 43 institutions in 10 countries. This large international collaboration is supported by US resources and significant foreign resources.

  8. Beam-beam study of ERL based eRHIC

    E-Print Network [OSTI]

    Hao, Y; Ptitsyn, V

    2014-01-01

    Beam-beam effects in eRHIC, the proposed ERL-based Electron-Ion Collider (EIC) at BNL, have several unique features distinguishing them from those in hadron-colliders and lepton-colliders. Taking the advantage of the fact that the electron beam is used only once, we expect the luminosity to be 10 times greater than for the ring-ring collision scheme with similar parameters. However, without instituting proper treatments, the quality of electron and hadron beams can undergo degradation or even beam loss, driven by the beam-beam interactions. We will discuss the harmful effects, including the disruption and mismatch effect of the electron beam, the kink instability and the noise heating of the ion beam and the possible countermeasures.

  9. Jet Physics with A Large Ion Collider Experiment at the Large Hadron Collider

    E-Print Network [OSTI]

    Klein, Jochen

    In the presence of the strongly-interacting medium created in relativistic heavy-ion collisions, highly energetic partons from hard interactions lose energy through scattering and radiating. This effect, referred to as jet quenching, is observed as a suppression of particles with large momenta transverse to the beam axis (high-$p_\\perp$). To study the impact of the medium evolution on the energy loss modelling in the Monte Carlo event generator JEWEL, we compare results obtained for different scenarios of Au-Au collisions at $\\sqrt{s_\\mathrm{NN}} = 200~\\mathrm{GeV}$. For this purpose, JEWEL was extended to use the output of relativistic hydrodynamic calculations in the OSCAR2008H format. We find the modelling of common observables, e.g. the nuclear modification factor, to be rather insensitive to the details of the medium evolution, for which the analytically accessible Bjorken expansion can thus be considered adequate. The OSCAR interface now allows further studies also at LHC energies. Jets of large transve...

  10. Measurements of phi meson production in relativistic heavy-ion collisions at the BNL Relativistic Heavy Ion Collider (RHIC)

    E-Print Network [OSTI]

    Sakuma, Tai

    We present results for the measurement of ? meson production via its charged kaon decay channel ??K[superscript +]K[superscript -] in Au+Au collisions at ?(s[subscript NN])=62.4,130, and 200 GeV, and in p+p and d+Au ...

  11. Science Requirements and Conceptual Design for a Polarized Medium Energy Electron-Ion Collider at Jefferson Lab

    E-Print Network [OSTI]

    Abeyratne, S; Ahmed, S; Barber, D; Bisognano, J; Bogacz, A; Castilla, A; Chevtsov, P; Corneliussen, S; Deconinck, W; Degtiarenko, P; Delayen, J; Derbenev, Ya; DeSilva, S; Douglas, D; Dudnikov, V; Ent, R; Erdelyi, B; Evtushenko, P; Filatov, Yu; Gaskell, D; Geng, R; Guzey, V; Horn, T; Hutton, A; Hyde, C; Johnson, R; Kim, Y; Klein, F; Kondratenko, A; Kondratenko, M; Krafft, G; Li, R; Lin, F; Manikonda, S; Marhauser, F; McKeown, R; Morozov, V; Nadel-Turonski, P; Nissen, E; Ostroumov, P; Pivi, M; Pilat, F; Poelker, M; Prokudin, A; Rimmer, R; Satogata, T; Sayed, H; Spata, M; Sullivan, M; Tennant, C; Terzi?, B; Tiefenback, M; Wang, H; Wang, S; Weiss, C; Yunn, B; Zhang, Y

    2012-01-01

    This report presents a brief summary of the science opportunities and program of a polarized medium energy electron-ion collider at Jefferson Lab and a comprehensive description of the conceptual design of such a collider based on the CEBAF electron accelerator facility.

  12. Science Requirements and Conceptual Design for a Polarized Medium Energy Electron-Ion Collider at Jefferson Lab

    E-Print Network [OSTI]

    S. Abeyratne; A. Accardi; S. Ahmed; D. Barber; J. Bisognano; A. Bogacz; A. Castilla; P. Chevtsov; S. Corneliussen; W. Deconinck; P. Degtiarenko; J. Delayen; Ya. Derbenev; S. DeSilva; D. Douglas; V. Dudnikov; R. Ent; B. Erdelyi; P. Evtushenko; Yu. Filatov; D. Gaskell; R. Geng; V. Guzey; T. Horn; A. Hutton; C. Hyde; R. Johnson; Y. Kim; F. Klein; A. Kondratenko; M. Kondratenko; G. Krafft; R. Li; F. Lin; S. Manikonda; F. Marhauser; R. McKeown; V. Morozov; P. Nadel-Turonski; E. Nissen; P. Ostroumov; M. Pivi; F. Pilat; M. Poelker; A. Prokudin; R. Rimmer; T. Satogata; H. Sayed; M. Spata; M. Sullivan; C. Tennant; B. Terzi?; M. Tiefenback; H. Wang; S. Wang; C. Weiss; B. Yunn; Y. Zhang

    2012-09-05

    This report presents a brief summary of the science opportunities and program of a polarized medium energy electron-ion collider at Jefferson Lab and a comprehensive description of the conceptual design of such a collider based on the CEBAF electron accelerator facility.

  13. Analysis of failed ramps during the RHIC FY09 run

    SciTech Connect (OSTI)

    Minty, M.

    2014-08-15

    The Relativistic Heavy Ion Collider (RHIC) is a versatile accelerator that supports operation with polarized protons of up to 250 GeV and ions with up to 100 GeV/nucleon. During any running period, various operating scenarios with different particle species, beam energies or accelerator optics are commissioned. In this report the beam commissioning periods for establishing full energy beams (ramp development periods) from the FY09 run are summarized and, for the purpose of motivating further developments, we analyze the reasons for all failed ramps.

  14. Universal QGP Hadronization Conditions at RHIC and LHC

    E-Print Network [OSTI]

    Johann Rafelski; Michal Petran

    2014-06-07

    We address the principles governing QGP hadronization and particle production in relativistic heavy-ion collisions. We argue that chemical non-equilibrium is required and show that once this condition is assumed a very good description of hadron production in collider RHIC and at LHC heavy ion experiments follows. We present results of our analysis as a function of centrality. Comparing most extreme experimental conditions we show that only the reaction volume and degree of strangeness phase space saturation change. We determine the universal QGP fireball hadronization conditions.

  15. The RHIC and RHIC pre-injectors controls systems: status and plans

    SciTech Connect (OSTI)

    Brown, K.A.; Altinbas, Z.; Aronson, J.; Binello, S.; Campbell, I.; Costanzo, M.; D

    2011-10-10

    For the past twelve years experiments at the Relativistic Heavy Ion Collider (RHIC) have recorded data from collisions of heavy ions and polarized protons, leading to important discoveries in nuclear physics and the spin dynamics of quarks and gluons. BNL is the site of one of the first and still operating alternating gradient synchrotrons, the AGS, which first operated in 1960. The accelerator controls systems for these instruments span multiple generations of technologies. In this report we will describe the current status of the Collider-Accelerator Department controls systems, which are used to control seven different accelerator facilities and multiple science programs (high energy nuclear physics, high energy polarized proton physics, NASA programs, isotope production, and multiple accelerator research and development projects). We will describe the status of current projects, such as the just completed Electron Beam Ion Source (EBIS), our R&D programs in superconducting RF and an Energy Recovery LINAC (ERL), innovations in feedback systems and bunched beam stochastic cooling at RHIC, and plans for future controls system developments.

  16. A description of the pseudorapidity distributions in heavy ion collisions at RHIC and LHC energies

    E-Print Network [OSTI]

    Jiang, Z J; Zhang, H L; Deng, H P

    2015-01-01

    The charged particles produced in nucleus-nucleus collisions are classified into two parts,One is from the hot and dense matter created in collisions. The other is from leading particles. The hot and dense matter is assumed to expand and generate particles according to BJP hydrodynamics, a theory put forward by A. Bialas, R. A. Janik and R. Peschanski. The leading particles are argued to possess a Gaussian rapidity distribution with the normalization constant equaling the number of participants. A comparison is made between the theoretical results and the experimental measurements performed by BRAHMS and PHOBOS Collaboration at BNL-RHIC in Au-Au and Cu-Cu collisions at sqrt(s_NN)=200 GeV and by ALICE Collaboration at CERN-LHC in Pb-Pb collisions at sqrt(s_NN) =2.76 TeV. The theoretical results are well consistent with experimental data.

  17. $?/s$ of a Relativistic Hadron Gas at RHIC: Approaching the AdS/CFT bound?

    E-Print Network [OSTI]

    N. Demir; S. A. Bass

    2009-09-18

    Ultrarelativistic heavy-ion collisions at the Relativistic Heavy Ion Collider (RHIC) are thought to have produced a state of matter called the quark-gluon plasma, characterized by a very small shear-viscosity to entropy-density ratio $\\eta/s$, near the lower bound predicted for that quantity by AdS/CFT methods. As the produced matter expands and cools, it evolves through a phase described by a hadron gas with rapidly increasing $\\eta/s$. We calculate $\\eta/s$ as a function of temperature in this phase both in and out of chemical equilibrium and find that its value poses a challenge for viscous relativistic hydrodynamics, which requires small values of $\\eta/s$ in order to successfully describe the collective flow observables at RHIC. We therefore conclude that the origin of the low viscosity matter at the RHIC must be in the partonic phase of the reaction.

  18. ELECTRON ACCELERATION FOR E-RHIC WITH THE NON-SCALING FFAG.

    SciTech Connect (OSTI)

    TRBOJEVIC,D.BALSKIEWICZ,M.COURANT,E.D.ET AL.

    2004-07-05

    A non-scaling FFAG lattice design to accelerate electrons from 3.2 to 10 GeV is described. This is one of possible solutions for the future electron-ion collider (eRHIC) at Relativistic Heavy Ion Collier (RHIC) at Brookhaven National Laboratory (BNL). The e-RHIC proposal requires acceleration of the low emittance electrons up to energy of 10 GeV. To reduce a high cost of the full energy super-conducting linear accelerator an alternative approach with the FFAG is considered. The report describes the 1277 meters circumference non-scaling FFAG ring. The Courant-Snyder functions, orbit offsets, momentum compaction, and path length dependences on momentum during acceleration are presented.

  19. The Design of a Large Booster Ring for the Medium Energy Electron-Ion Collider at Jlab

    SciTech Connect (OSTI)

    Edward Nissen, Todd Satogata, Yuhong Zhang

    2012-07-01

    In this paper, we present the current design of the large booster ring for the Medium energy Electron-Ion Collider at Jefferson Lab. The booster ring takes 3 GeV protons or ions of equivalent rigidity from a pre-booster ring, and accelerates them to 20 GeV for protons or equivalent energy for light to heavy ions before sending them to the ion collider ring. The present design calls for a figure-8 shape of the ring for superior preservation of ion polarization. The ring is made of warm magnets and shares a tunnel with the two collider rings. Acceleration is achieved by warm RF systems. The linear optics has been designed with the transition energy above the highest beam energy in the ring so crossing of transition energy will be avoided. Preliminary beam dynamics studies including chromaticity compensation are presented in this paper.

  20. Calculation of synchrotron radiation from high intensity electron beam at eRHIC

    SciTech Connect (OSTI)

    Jing Y.; Chubar, O.; Litvinenko, V.

    2012-05-20

    The Electron-Relativistic Heavy Ion Collider (eRHIC) at Brookhaven National Lab is an upgrade project for the existing RHIC. A 30 GeV energy recovery linac (ERL) will provide a high charge and high quality electron beam to collide with proton and ion beams. This will improve the luminosity by at least 2 orders of magnitude. The synchrotron radiation (SR) from the bending magnets and strong quadrupoles for such an intense beam could be penetrating the vacuum chamber and producing hazards to electronic devices and undesired background for detectors. In this paper, we calculate the SR spectral intensity, power density distributions and heat load on the chamber wall. We suggest the wall thickness required to stop the SR and estimate spectral characteristics of the residual and scattered background radiation outside the chamber.

  1. Vladimir Litvinenko, January 23,2006, RHIC Machine Advisory Committee EBIS Booster

    E-Print Network [OSTI]

    Vladimir Litvinenko, January 23,2006, RHIC Machine Advisory Committee Linac EBIS Booster AGS RHIC, Brookhaven National Laboratory, Upton, NY, USA #12;Vladimir Litvinenko, January 23,2006, RHIC Machine Electron cooling for RHIC II - Wrap-up Vladimir N. Litvinenko for C-AD team Collider Accelerator Department

  2. Status of the MEIC ion collider ring design (Conference) | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfateSciTechtail. (Conference)Feedback System inStatus of the MEIC ion collider ring design Citation

  3. STAR Highlights on Heavy Ion Physics

    E-Print Network [OSTI]

    Shusu Shi

    2014-09-30

    RHIC-STAR is a mid-rapidity collider experiment for studying high energy nuclear collisions. The main physics goals of STAR experiment are 1) studying the properties of the strongly coupled Quark Gluon Plasma, 2) explore the QCD phase diagram structure. In these proceedings, we will review the recent results of heavy ion physics at STAR.

  4. Nuclear physics with a medium-energy Electron-Ion Collider

    E-Print Network [OSTI]

    Accardi, A; Prokudin, A; Weiss, C

    2011-01-01

    A polarized ep/eA collider (Electron-Ion Collider, or EIC) with variable center-of-mass energy sqrt(s) ~ 20-70 GeV and a luminosity ~ 10^{34} cm^{-2} s^{-1} would be uniquely suited to address several outstanding questions of Quantum Chromodynamics (QCD) and the microscopic structure of hadrons and nuclei: (i) the three-dimensional structure of the nucleon in QCD (sea quark and gluon spatial distributions, orbital motion, polarization, correlations); (ii) the fundamental color fields in nuclei (nuclear parton densities, shadowing, coherence effects, color transparency); (iii) the conversion of color charge to hadrons (fragmentation, parton propagation through matter, in-medium jets). We briefly review the conceptual aspects of these questions and the measurements that would address them, emphasizing the qualitatively new information that could be obtained with the collider. Such a medium-energy EIC could be realized at Jefferson Lab after the 12 GeV Upgrade (MEIC), or at Brookhaven National Lab as the low-ene...

  5. Latest Results from BNL and RHIC--2013

    E-Print Network [OSTI]

    M. J. Tannenbaum

    2014-04-22

    A selection of results from the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL) from 2012 to 2013 is presented together with a few newsworthy developments in this period. The move of the g-2 magnet from BNL to Fermilab for the "fifth muon g-2 experiment" inspired a brief discussion of the original g-2 experiments at CERN. Highlights of the past year include a change in the measurement of the suppression of large transverse momentum ($p_T$) particles in the Quark Gluon Plasma to a measure of the fractional shift in the observed $p_T$ spectrum from the expected A+A spectrum for independent collisions as an estimate of the energy loss in the medium. The p+Pb run at LHC in early 2013 spurred new or improved measurements in d+Au at RHIC which included the observation of elliptical flow in d+Au collisions and measurements of transverse energy ($E_T$) spectra in p-p, d+Au and Au+Au collisions at 200 GeV nucleon-nucleon c.m. energy which demonstrated that constituent quarks are the fundamental element of particle production in all 3 systems. Measurements of identified hadrons in d+Au show a huge Cronin effect for protons but no effect for mesons. An important step for the future was the acquisition by BNL of the superconducting solenoid used in the BABAR experiment at SLAC for use in future experiments at RHIC and possibly eRHIC, starting with an upgrade of the PHENIX experiment called sPHENIX.

  6. Tests of an RF Dipole Crabbing Cavity for an Electron-Ion Collider

    SciTech Connect (OSTI)

    Castilla Loeza, Alejandro; Delayen, Jean R.

    2013-12-01

    On the scheme of developing a medium energy electron-ion collider (MEIC) at Jefferson Lab, we have designed a compact superconducting rf dipole cavity at 750 MHz to crab both electron and ion bunches and increase luminosities at the interaction points (IP) of the machine. Following the design optimization and characterization of the electromagnetic properties such as peak surface fields and shunt impedance, along with field nonuniformities, multipole components content, higher order modes (HOM) and multipacting, a prototype cavity was built by Niowave Inc. The 750 MHz prototype crab cavity has been tested at 4 K and is ready for re-testing at 4 K and 2 K at Jefferson Lab. In this paper we present the detailed results of the rf tests performed on the 750 MHz crab cavity prototype.

  7. Probing the Quark Sea and Gluons: the Electron-Ion Collider Projects

    SciTech Connect (OSTI)

    Rolf Ent

    2012-04-01

    EIC is the generic name for the nuclear science-driven Electron-Ion Collider presently considered in the US. Such an EIC would be the world’s first polarized electron-proton collider, and the world’s first e-A collider. Very little remains known about the dynamical basis of the structure of hadrons and nuclei in terms of the fundamental quarks and gluons of Quantum Chromodynamics (QCD). A large community effort to sharpen a compelling nuclear science case for an EIC occurred during a ten-week program taking place at the Institute for Nuclear Theory (INT) in Seattle from September 13 to November 19, 2010. The critical capabilities of a stage-I EIC are a range in center-of-mass energies from 20 to 70 GeV and variable, full polarization of electrons and light ions (the latter both longitudinal and transverse), ion species up to A=200 or so, multiple interaction regions, and a high luminosity of about 10{sup 34} electron-nucleons per cm{sup 2} and per second. The physics program of such a stage-I EIC encompass inclusive measurements (ep/A{yields}e'+X), which require detection of the scattered lepon and/or the full scattered hadronic debris with high precision, semi-inclusive processes (ep/A{yields}e'+h+X), which require detection in coincidence with the scattered lepton of at least one (current or target region) hadron; and exclusive processes (ep/A{yields}e'+N'/A'+{gamma}/m), which require detection of all particles in the reaction. The main science themes of an EIC are to i) map the spin and spatial structure of quarks and gluons in nucleons, ii) discover the collective effects of gluons in atomic nuclei, and (iii) understand the emergence of hadronic matter from color charge. In addition, there are opportunities at an EIC for fundamental symmetry and nucleon structure measurements using the electroweak probe. To truly make headway to image the sea quarks and gluons in nucleons and nuclei, the EIC needs high luminosity over a range of energies as more exclusive scattering probabilities are small, and any integrated detector/interaction region design needs to provide uniform coverage to detect spectator and diffractive products. This is because e-p and even more e-A colliders have a large fraction of their science related to what happens to the nucleon or ion beams. As a result, the philosophy of integration of complex detectors into an extended interaction region faces challenging constraints. Designs feature crossing angles between the protons or heavy ions during collisions with electrons, to remove potential problems for the detector induced by synchrotron radiation. Designs allocate quite some detector space before the final-focus ion quads, at the cost of luminosity, given that uniform detection coverage is a must for deep exclusive and diffractive processes. The integrated EIC detector/interaction region design at JLab focused on establishing full acceptance for such processes over a wide range of proton energies (20-100 GeV) with well achievable interaction region magnets. The detector design at BNL uses the higher ion beam energies to achieve good detection efficiency for instance for protons following a DVCS reaction, for proton beam energies starting from 100 GeV. Following a recommendation of the 2007 US Nuclear Science Long-Range Planning effort, the DOE Office of Nuclear Physics (DOE/NP) has allocated accelerator R&D funds to lay the foundation for a polarized EIC. BNL, in association with JLab and DOE/NP, has also established a generic detector R&D program to address the scientific requirements for measurements at a future EIC.

  8. The effects of the RHIC E-lenses magnetic structure layout on the proton beam trajectory

    SciTech Connect (OSTI)

    Gu, X.; Pikin, A.; Luo, Y.; Okamura, M.; Fischer, W.; Gupta, R.; Hock, J.; Raparia, D.

    2011-03-28

    We are designing two electron lenses (E-lens) to compensate for the large beam-beam tune spread from proton-proton interactions at IP6 and IP8 in the Relativistic Heavy Ion Collider (RHIC). They will be installed in RHIC IR10. First, the layout of these two E-lenses is introduced. Then the effects of e-lenses on proton beam are discussed. For example, the transverse fields of the e-lens bending solenoids and the fringe field of the main solenoids will shift the proton beam. For the effects of the e-lens on proton beam trajectory, we calculate the transverse kicks that the proton beam receives in the electron lens via Opera at first. Then, after incorporating the simplified E-lens lattice in the RHIC lattice, we obtain the closed orbit effect with the Simtrack Code.

  9. Study of Charmonium Production in Asymmetric Nuclear Collisions by the PHENIX Experiment at RHIC

    E-Print Network [OSTI]

    Alexandre Lebedev

    2015-09-11

    The measurement of quarkonia production in relativistic heavy ion collisions provides a powerful tool for studying the properties of the hot and dense matter created in these collisions. To be really useful, however, such measurements must cover a wide range of quarkonia states and colliding species. The PHENIX experiment at RHIC has successfully measured J/psi, psi-prime, chi_c and Upsilon production in different colliding systems at various energies. In this talk I will present recent results from the PHENIX collaboration on charmonium production in d+Au, Cu+Au and U+U collisions at 200 GeV/c.

  10. Ultra-peripheral collisions of heavy ions at RHIC and the LHC

    E-Print Network [OSTI]

    Joakim Nystrand

    2006-11-03

    This paper deals with so-called Ultra-Peripheral Collisions (UPCs) of heavy ions. These can be defined as collisions in which no hadronic interactions occur because of the large spatial separation between the projectile and target. The interactions are instead mediated by the electromagnetic field. Two types of ultra-peripheral collisions can be distinguished: purely electro-magnetic interactions (two-photon interactions) and photonuclear interactions, in which a photon from the projectile interacts with the hadronic component of the target.

  11. Elliptic Flow, Initial Eccentricity and Elliptic Flow fluctuations in Heavy Ion Collisions at RHIC

    E-Print Network [OSTI]

    Rachid Nouicer; for the PHOBOS Collaboration

    2007-07-30

    We present measurements of elliptic flow and event-by-event fluctuations established by the PHOBOS experiment. Elliptic flow scaled by participant eccentricity is found to be similar for both systems when collisions with the same number of participants or the same particle area density are compared. The agreement of elliptic flow between Au+Au and Cu+Cu collisions provides evidence that the matter is created in the initial stage of relativistic heavy ion collisions with transverse granularity similar to that of the participant nucleons. The event-by-event fluctuation results reveal that the initial collision geometry is translated into the final state azimuthal particle distribution, leading to an event-by-event proportionality between the observed elliptic flow and initial eccentricity.

  12. Effect of Triplet Magnet Vibrations on RHIC Performance with High Energy Protons

    SciTech Connect (OSTI)

    Minty, M.

    2010-05-23

    In this report we present recent experimental data from the Relativistic Heavy Ion Collider (RHIC) illustrating effects resulting from {approx}10 Hz vibrations of the triplet quadrupole magnets in the interactions regions and evaluate the impact of these vibrations on RHIC collider performance. Measurements revealed modulation of the betatron tunes of appreciable magnitude relative to the total beam-beam parameter. Comparison of the discrete frequencies in the spectra of the measured beam positions and betatron tunes confirmed a common source. The tune modulations were shown to result from feed-down in the sextupole magnets in the interaction regions. In addition we show that the distortions to the closed orbit of the two counter-rotating beams produced a modulated crossing angle at the interaction point(s).

  13. Simulation Studies of Beam-Beam Effects of a Ring-Ring Electron-Ion Collider Based on CEBAF

    SciTech Connect (OSTI)

    Yuhong Zhang,Ji Qiang

    2009-05-01

    The collective beam-beam effect can potentially cause a rapid growth of beam sizes and reduce the luminosity of a collider to an unacceptably low level. The ELIC, a proposed ultra high luminosity electron-ion collider based on CEBAF, employs high repetition rate crab crossing colliding beams with very small bunch transverse sizes and very short bunch lengths, and collides them at up to 4 interaction points with strong final focusing. All of these features can make the beam-beam effect challenging. In this paper, we present simulation studies of the beam-beam effect in ELIC using a self-consistent strong-strong beam-beam simulation code developed at Lawrence Berkeley National Laboratory. This simulation study is used for validating the ELIC design and for searching for an optimal parameter set.

  14. Ion bunch length effects on the beam-beam interaction and its compensation in a high-luminosity ring-ring electron-ion collider

    SciTech Connect (OSTI)

    Montag C.; Oeftiger, A.; Fischer, W.

    2012-05-20

    One of the luminosity limits in a ring-ring electron-ion collider is the beam-beam effect on the electrons. In the limit of short ion bunches, simulation studies have shown that this limit can be significantly increased by head-on beam-beam compensation with an electron lens. However, with an ion bunch length comparable to the beta-function at the IP in conjunction with a large beam-beam parameter, the electrons perform a sizeable fraction of a betatron oscillation period inside the long ion bunches. We present recent simulation results on the compensation of this beam-beam interaction with multiple electron lenses.

  15. Latest Results from BNL and RHIC--2013

    E-Print Network [OSTI]

    Tannenbaum, M J

    2014-01-01

    A selection of results from the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL) from 2012 to 2013 is presented together with a few newsworthy developments in this period. The move of the g-2 magnet from BNL to Fermilab for the "fifth muon g-2 experiment" inspired a brief discussion of the original g-2 experiments at CERN. Highlights of the past year include a change in the measurement of the suppression of large transverse momentum ($p_T$) particles in the Quark Gluon Plasma to a measure of the fractional shift in the observed $p_T$ spectrum from the expected A+A spectrum for independent collisions as an estimate of the energy loss in the medium. The p+Pb run at LHC in early 2013 spurred new or improved measurements in d+Au at RHIC which included the observation of elliptical flow in d+Au collisions and measurements of transverse energy ($E_T$) spectra in p-p, d+Au and Au+Au collisions at 200 GeV nucleon-nucleon c.m. energy which demonstrated that constituent quarks are the fund...

  16. Gluon saturation and pseudo-rapidity distributions of charged hadrons at RHIC energy regions

    E-Print Network [OSTI]

    Xin-Bin Wei; Sheng-Qin Feng

    2014-11-20

    We modified the gluon saturation model by rescaling the momentum fraction according to saturation momentum and introduced the Cooper-Frye hydrodynamic evolution to systematically study the pseudo-rapidity distributions of final charged hadrons at different energies and different centralities for Au-Au collisions in relativistic heavy-ion collisions at BNL Relativistic Heavy Ion Collider (RHIC). The features of both gluon saturation and hydrodynamic evolution at different energies and different centralities for Au-Au collisions are investigated in this paper.

  17. Global Observables at RHIC

    E-Print Network [OSTI]

    A. Milov

    2006-10-17

    Main characteristics of the charged particle dN_ch/deta and transverse energy dE_T/deta production measured in Heavy Ion collisions at RHIC energies are presented in this article. Transformation of the pseudo-rapidity shape, relation to the incident energy and centrality profile are described in a systematic way. Centrality profile is shown to be closely bound to the number of nucleons participating in the collisions, at the same time an alternative approach to study the centrality behavior is also discussed.

  18. Reconstructed Jets at RHIC

    E-Print Network [OSTI]

    Sevil Salur

    2010-04-30

    To precisely measure jets over a large background such as pile up in high luminosity p+p collisions at LHC, a new generation of jet reconstruction algorithms is developed. These algorithms are also applicable to reconstruct jets in the heavy ion environment where large event multiplicities are produced. Energy loss in the medium created in heavy ion collisions are already observed indirectly via inclusive hadron distributions and di-hadron correlations. Jets can be used to study this energy loss in detail with reduced biases. We review the latest results on jet-medium interactions as seen in A+A collisions at RHIC, focusing on the recent progress on jet reconstruction in heavy ion collisions.

  19. The E-lens test bench for RHIC beam-beam compensation

    SciTech Connect (OSTI)

    Gu X.; Altinbas, F.Z.; Aronson, J.; Beebe, E. et al

    2012-05-20

    To compensate for the beam-beam effects from the proton-proton interactions at IP6 and IP8 in the Relativistic Heavy Ion Collider (RHIC), we are fabricating two electron lenses that we plan to install at RHIC IR10. Before installing the e-lenses, we are setting-up the e-lens test bench to test the electron gun, collector, GS1 coil, modulator, partial control system, some instrumentation, and the application software. Some e-lens power supplies, the electronics for current measurement will also be qualified on test bench. The test bench also was designed for measuring the properties of the cathode and the profile of the beam. In this paper, we introduce the layout and elements of the e-lens test bench; and we discuss its present status towards the end of this paper.

  20. Electron Spin Rotation And Matching Scheme For ELIC, A High-Luminosity Ring-Ring Electron-Ion Collider

    SciTech Connect (OSTI)

    Bogacz, A.; Chevtsov, P.; Derbenev, Y.; Krafft, G.; Zhang, Y.

    2009-08-04

    A unique design feature of a polarized Electron-Ion Collider (ELIC) based on CEBAF is its Figure-8 shaped storage rings for both electrons and ions, which significantly simplifies beam polarization maintenance and manipulation. The CEBAF accelerator is used as a full energy injector of polarized electron beams into the electron storage ring. While electron polarization is maintained vertical in arcs of the ring, a stable longitudinal spin at four collision points is achieved through vertical crossing bending magnets, solenoid spin rotators, and horizontal orbit bends. Spin matching technique needs to be implemented in order to enhance quantum self-polarization and minimize depolarization effects. In this paper, we also discuss several important issues related to the use of positron beams, radiative polarization and quantum depolarization effects, as well as spin in ELIC.

  1. Noise estimation of beam position monitors at RHIC

    SciTech Connect (OSTI)

    Shen, X.; Bai, M.; Lee, S. Y.

    2014-02-10

    Beam position monitors (BPM) are used to record the average orbits and transverse turn-by-turn displacements of the beam centroid motion. The Relativistic Hadron Ion Collider (RHIC) has 160 BPMs for each plane in each of the Blue and Yellow rings: 72 dual-plane BPMs in the insertion regions (IR) and 176 single-plane modules in the arcs. Each BPM is able to acquire 1024 or 4096 consecutive turn-by-turn beam positions. Inevitably, there are broadband noisy signals in the turn-by-turn data due to BPM electronics as well as other sources. A detailed study of the BPM noise performance is critical for reliable optics measurement and beam dynamics analysis based on turn-by-turn data.

  2. Modeling of RHIC insulating vacuum for system pumpdown characteristics

    SciTech Connect (OSTI)

    Todd, R.J.; Pate, D.J.; Welch, K.M.

    1993-06-01

    This paper presents a model for predicting the pumpdown characteristics of a 480 m RHIC (Relativistic Heavy Ion Collider) vacuum cryostat. The longitudinal and transverse conductances of a typical cryostat were calculated. A voltage analogue of these conductances was constructed for room temperature conditions. The total longitudinal conductance of a room temperature cryostat was thereby achieved. This conductance was then used to calculate the diameter of an equivalent long outgassing tube, having more convenient analytical expressions for pressure profiles when pumped. The equivalent of a unit outgassing rate for this tube was obtained using previously published MLI (multi-layer insulation) outgassing data. With this model one is then able to predict a cryostat pumpdown rate as a function of the location and size of roughing pumps.

  3. Anisotropic Flow from RHIC to the LHC

    E-Print Network [OSTI]

    Raimond Snellings

    2006-10-05

    Anisotropic flow is recognized as one of the main observables providing information on the early stage of a heavy-ion collision. At RHIC the large observed anisotropic flow and its successful description by ideal hydrodynamics is considered evidence for an early onset of thermalization and almost ideal fluid properties of the produced strongly coupled Quark Gluon Plasma. This write-up discusses some key RHIC anisotropic flow measurements and for anisotropic flow at the LHC some predictions.

  4. Direct Photons at RHIC

    E-Print Network [OSTI]

    G. David; for the PHENIX Collaboration

    2008-10-21

    Direct photons are ideal tools to investigate kinematical and thermodynamical conditions of heavy ion collisions since they are emitted from all stages of the collision and once produced they leave the interaction region without further modification by the medium. The PHENIX experiment at RHIC has measured direct photon production in p+p and Au+Au collisions at 200 GeV over a wide transverse momentum ($p_T$) range. The $p$ + $p$ measurements allow a fundamental test of QCD, and serve as a baseline when we try to disentangle more complex mechanisms producing high $p_T$ direct photons in Au+Au. As for thermal photons in Au+Au we overcome the difficulties due to the large background from hadronic decays by measuring "almost real" virtual photons which appear as low invariant mass $e^+e^-$ pairs: a significant excess of direct photons is measured above the above next-to-leading order perturbative quantum chromodynamics calculations. Additional insights on the origin of direct photons can be gained with the study of the azimuthal anisotropy which benefits from the increased statistics and reaction plane resolution achieved in RHIC Year-7 data.

  5. Stability of Single Particle Motion with Head-On Beam-Beam Compensation in the RHIC

    SciTech Connect (OSTI)

    Luo,Y.; Fischer, W.; Abreu, N.

    2008-05-01

    To compensate the large tune shift and tune spread generated by the head-on beam-beam interactions in the polarized proton run in the Relativistic Heavy Ion Collider (RHIC), we proposed a low energy electron beam with a Gaussian transverse profiles to collide head-on with the proton beam. In this article, with a weak-strong beam-beam interaction model, we investigate the stability of single particle motion in the presence of head-on beam-beam compensation. Tune footprints, tune diffusion, Lyapunov exponents, and 10{sup 6} turn dynamic apertures are calculated and compared between the cases without and with beam-beam compensation. A tune scan is performed and the possibility of increasing the bunch intensity is studied. The cause of tune footprint foldings is discussed, and the tune diffusion and Lyapunov exponent analysis are compared.

  6. Stochastic Boundary, Diffusion, Emittance Growth and Lifetime calculation for the RHIC e-lens

    SciTech Connect (OSTI)

    Abreu,N.P.; Fischer, W.; Luo, Y.; Robert-Demolaize, G.

    2009-01-20

    To compensate the large tune shift and tune spread generated by the head-on beam-beam interactions in polarized proton operation in the Relativistic Heavy Ion Collider (RHIC), a low energy electron beam with proper Gaussian transverse profiles was proposed to collide head-on with the proton beam. In this article, using a modified version of SixTrack [1], we investigate stability of the single particle in the presence of head-on beam-beam compensation. The Lyapunov exponent and action diffusion are calculated and compared between the cases without and with beam-beam compensation for two different working points and various bunch intensities. Using the action diffusion results the emittance growth rate and lifetime of the proton beam is also estimated for the different scenarios.

  7. Can Doubly Strange Dibaryon Resonances be Discovered at RHIC?

    E-Print Network [OSTI]

    S. D. Paganis; G. W. Hoffmann; R. L. Ray; J. -L. Tang; T. Udagawa; R. S. Longacre

    2000-06-12

    The baryon-baryon continuum invariant mass spectrum generated from relativistic nucleus + nucleus collision data may reveal the existence of doubly-strange dibaryons not stable against strong decay if they lie within a few MeV of threshold. Furthermore, since the dominant component of these states is a superposition of two color-octet clusters which can be produced intermediately in a color-deconfined quark-gluon plasma (QGP), an enhanced production of dibaryon resonances could be a signal of QGP formation. A total of eight, doubly-strange dibaryon states are considered for experimental search using the STAR detector (Solenoidal Tracker at RHIC) at the new Relativistic Heavy Ion Collider (RHIC). These states may decay to Lambda-Lambda and/or proton-Cascade-minus, depending on the resonance energy. STAR's large acceptance, precision tracking and vertex reconstruction capabilities, and large data volume capacity, make it an ideal instrument to use for such a search. Detector performance and analysis sensitivity are studied as a function of resonance production rate and width for one particular dibaryon which can directly strong decay to proton-Cascade-minus but not Lambda-Lambda. Results indicate that such resonances may be discovered using STAR if the resonance production rates are comparable to coalescence model predictions for dibaryon bound states.

  8. Electromagnetic Measurements at RHIC

    E-Print Network [OSTI]

    Hamagaki, Hideki

    Electromagnetic Measurements at RHIC Hideki Hamagaki Center for Nuclear Study University of Tokyo #12;2/10/2005 "Electromagnetic measurements at RHIC"@ICPAQGP 05 Hideki Hamagaki 2 Prologue · EM probe and where they are produced; #12;2/10/2005 "Electromagnetic measurements at RHIC"@ICPAQGP 05 Hideki Hamagaki

  9. Electromagnetic Measurements at RHIC

    E-Print Network [OSTI]

    Hamagaki, Hideki

    Electromagnetic Measurements at RHIC Hideki Hamagaki Center for Nuclear Study Graduate School of Science the University of Tokyo #12;2006/06/29 "Electromagnetic measurements at RHIC"@ATHIC 2006 Hideki;2006/06/29 "Electromagnetic measurements at RHIC"@ATHIC 2006 Hideki Hamagaki 3 Prologue ­ scope of EM measurements · EM

  10. Selected experimental results from heavy-ion collisions at LHC

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Singh, Ranbir; Kumar, Lokesh; Netrakanti, Pawan Kumar; Mohanty, Bedangadas

    2013-01-01

    We review a subset of experimental results from the heavy-ion collisions at the Large Hadron Collider (LHC) facility at CERN. Excellent consistency is observed across all the experiments at the LHC (at center of mass energysNN=2.76 TeV) for the measurements such as charged particle multiplicity density, azimuthal anisotropy coefficients, and nuclear modification factor of charged hadrons. Comparison to similar measurements from the Relativistic Heavy Ion Collider (RHIC) at lower energy (sNN=200 GeV) suggests that the system formed at LHC has a higher energy density and larger system size and lives for a longer time. These measurements aremore »compared to model calculations to obtain physical insights on the properties of matter created at the RHIC and LHC.« less

  11. Production, formation, and transport of high-brightness atomic hydrogen beam studies for the relativistic heavy ion collider polarized source upgrade

    SciTech Connect (OSTI)

    Kolmogorov, A. Stupishin, N.; Atoian, G.; Ritter, J.; Zelenski, A.; Davydenko, V.; Ivanov, A.; Novosibirsk State University, Novosibirsk

    2014-02-15

    The RHIC polarized H{sup ?} ion source had been successfully upgraded to higher intensity and polarization by using a very high brightness fast atomic beam source developed at BINP, Novosibirsk. In this source the proton beam is extracted by a four-grid multi-aperture ion optical system and neutralized in the H{sub 2} gas cell downstream from the grids. The proton beam is extracted from plasma emitter with a low transverse ion temperature of ?0.2 eV which is formed by plasma jet expansion from the arc plasma generator. The multi-hole grids are spherically shaped to produce “geometrical” beam focusing. Proton beam formation and transport of atomic beam were experimentally studied at test bench.

  12. Energy dependence of directed flow over a wide range of pseudorapidity in Au+Au collisions at RHIC

    E-Print Network [OSTI]

    B. B. Back; for the PHOBOS Collaboration

    2006-07-08

    We report on measurements of directed flow as a function of pseudorapidity in Au+Au collisions at energies of $\\sqrt{s_{_{NN}}} =$ 19.6, 62.4, 130 and 200 GeV as measured by the PHOBOS detector at the Relativistic Heavy Ion Collider (RHIC). These results are particularly valuable because of the extensive, continuous pseudorapidity coverage of the PHOBOS detector. There is no significant indication of structure near midrapidity and the data surprisingly exhibit extended longitudinal scaling similar to that seen for elliptic flow and charged particle pseudorapidity density.

  13. Hadronic resonance production in d+Au collisions at root S(NN) = 200 GeV measured at the BNL Relativistic Heavy Ion Collider 

    E-Print Network [OSTI]

    Abelev, B. I.; Aggarwal, M. M.; Ahammed, Z.; Anderson, B. D.; Arkhipkin, D.; Averichev, G. S.; Bai, Y.; Balewski, J.; Barannikova, O.; Barnby, L. S.; Baudot, J.; Baumgart, S.; Beavis, D. R.; Bellwied, R.; Benedosso, F.; Betts, R. R.; Bhardwaj, S.; Bhasin, A.; Bhati, A. K.; Bichsel, H.; Bielcik, J.; Bielcikova, J.; Biritz, B.; Bland, L. C.; Bombara, M.; Bonner, B. E.; Botje, M.; Bouchet, J.; Braidot, E.; Brandin, A. V.; Bruna; Bueltmann, S.; Burton, T. P.; Bystersky, M.; Cai, X. Z.; Caines, H.; Sanchez, M. Calderon de la Barca; Callner, J.; Catu, O.; Cebra, D.; Cendejas, R.; Cervantes, M. C.; Chajecki, Z.; Chaloupka, P.; Chattopdhyay, S.; Chen, H. F.; Chen, J. H.; Chen, J. Y.; Cheng, J.; Cherney, M.; Chikanian, A.; Choi, K. E.; Christie, W.; Chung, S. U.; Clarke, R. F.; Codrington, M. J. M.; Coffin, J. P.; Cormier, T. M.; Cosentino, M. R.; Cramer, J. G.; Crawford, H. J.; Das, D.; Dash, S.; Daugherity, M.; De Silva, C.; Dedovich, T. G.; DePhillips, M.; Derevschikov, A. A.; de Souza, R. Derradi; Didenko, L.; Djawotho, P.; Dogra, S. M.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Du, F.; Dunlop, J. C.; Mazumdar, M. R. Dutta; Edwards, W. R.; Efimov, L. G.; Elhalhuli, E.; Elnimr, M.; Emelianov, V.; Engelage, J.; Eppley, G.; Erazmus, B.; Estienne, M.; Eun, L.; Fachini, P.; Fatemi, R.; Fedorisin, J.; Feng, A.; Filip, P.; Finch, E.; Fine, V.; Fisyak, Y.; Gagliardi, Carl A.; Gaillard, L.; Gangaharan, D. R.; Ganti, M. S.; Garcia-Solis, E.; Ghazikhanian, V.; Ghosh, P.; Gorbunov, Y. N.; Gordon, A.; Grebenyuk, O.; Grosnick, D.; Grube, B.; Guertin, S. M.; Guimaraes, K. S. F. F.; Gupta, A.; Gupta, N.; Guryn, W.; Haag, B.; Hallman, T. J.; Hamed, A.; Harris, J. W.; He, W.; Heinz, M.; Hepplemann, S.; Hippolyte, B.; Hirsch, A.; Hoffman, A. M.; Hoffmann, G. W.; Hofman, D. J.; Hollis, R. S.; Huang, H. Z.; Humanic, T. J.; Igo, G.; Iordanova, A.; Jacobs, P.; Jacobs, W. W.; Jakl, P.; Jin, F.; Jones, P. G.; Joseph, J.; Judd, E. G.; Kabana, S.; Kajimoto, K.; Kang, K.; Kapitan, J.; Kaplan, M.; Keane, D.; Kechechyan, A.; Kettler, D.; Khodyrev, V. Yu; Kiryluk, J.; Kisiel, A.; Klein, S. R.; Knospe, A. G.; Kocoloski, A.; Koetke, D. D.; Kopytine, M.; Kotchenda, L.; Kouchpil, V.; Kravtsov, P.; Kravtsov, V. I.; Krueger, K.; Krus, M.; Kuhn, C.; Kumar, L.; Kurnadi, P.; Lamont, M. A. C.; Landgraf, J. M.; LaPointe, S.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, C. -H; LeVine, M. J.; Li, C.; Li, Y.; Lin, G.; Lin, X.; Lindenbaum, S. J.; Lisa, M. A.; Liu, F.; Liu, H.; Liu, J.; Liu, L.; Ljubicic, T.; Llope, W. J.; Longacre, R. S.; Love, W. A.; Lu, Y.; Ludlam, T.; Lynn, D.; Ma, G. L.; Ma, Y. G.; Mahapatra, D. P.; Majka, R.; Mall, M. I.; Mangotra, L. K.; Manweiler, R.; Margetis, S.; Markert, C.; Matis, H. S.; Matulenko, Yu A.; McShane, T. S.; Meschanin, A.; Millane, J.; Miller, M. L.; Minaev, N. G.; Mioduszewski, Saskia; Mischke, A.; Mishra, D. K.; Mitchell, J.; Mohanty, B.; Morozov, D. A.; Munhoz, M. G.; Nandi, B. K.; Nattrass, C.; Nayak, T. K.; Nelson, J. M.; Nepali, C.; Netrakanti, P. K.; Ng, M. J.; Nogach, L. V.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Okada, H.; Okorokov, V.; Olson, D.; Pachr, M.; Page, B. S.; Pal, S. K.; Pandit, Y.; Panebratsev, Y.; Pawlak, T.; Peitzmann, T.; Perevoztchikov, V.; Perkins, C.; Peryt, W.; Phatak, S. C.; Planinic, M.; Pluta, J.; Poljak, N.; Poskanzer, A. M.; Potukuchi, B. V. K. S.; Prindle, D.; Pruneau, C.; Pruthi, N. K.; Putschke, J.; Raniwala, R.; Raniwala, S.; Ray, R. L.; Reed, R.; Ridiger, A.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Rose, A.; Roy, C.; Ruan, L.; Russcher, M. J.; Rykov, V.; Sahoo, R.; Sakrejda, I.; Sakuma, T.; Salur, S.; Sandweiss, J.; Sarsour, M.; Schambach, J.; Scharenberg, R. P.; Schmitz, N.; Seger, J.; Selyuzhenkov, I.; Seyboth, P.; Shabetai, A.; Shahaliev, E.; Shao, M.; Sharma, M.; Shi, S. S.; Shi, X-H; Sichtermann, E. P.; Simon, F.; Singaraju, R. N.; Skoby, M. J.; Smirnov, N.; Snellings, R.; Sorensen, P.; Sowinski, J.; Spinka, H. M.; Srivastava, B.; Stadnik, A.; Stanislaus, T. D. S.; Staszak, D.; Strikhanov, M.; Stringfellow, B.; Suaide, A. A. P.; Suarez, M. C.; Subba, N. L.; Sumbera, M.; Sun, X. M.; Sun, Y.; Sun, Z.; Surrow, B.; Symons, T. J. M.; deToledo, A. Szanto; Takahashi, J.; Tang, A. H.; Tang, Z.; Tarnowsky, T.; Thein, D.; Thomas, J. H.; Tian, J.; Timmins, A. R.; Timoshenko, S.; Tlusty; Tokarev, M.; Trainor, T. A.; Tram, V. N.; Trattner, A. L.; Trentalange, S.; Tribble, Robert E.; Tsai, O. D.; Ulery, J.; Ullrich, T.; Underwood, D. G.; Van Buren, G.; van Leeuwen, M.; Molen, A. M. Vander; Vanfossen, J. A., Jr.; Varma, R.; Vasconcelos, G. M. S.; Vasilevski, I. M.; Vasiliev, A. N.; Videbaek, F.; Vigdor, S. E.; Viyogi, Y. P.; Vokal, S.; Voloshin, S. A.; Wada, M.; Waggoner, W. T.; Wang, F.; Wang, G.; Wang, J. S.; Wang, Q.; Wang, X.

    2008-01-01

    tracker at the BNL Relativistic Heavy Ion Collider). The masses and widths of these resonances are studied as a function of transverse momentum p(T). We observe that the resonance spectra follow a generalized scaling law with the transverse mass m...

  14. RHIC Operation and Plans for Upgrades Wolfram Fischer

    E-Print Network [OSTI]

    Ã? design 10Ã? achieved #12;Wolfram Fischer 7 Achieved parameters Mode No of bunches Ions/bunch [ 1 0 9] enhanced luminosity 60e9 Au intensity design luminosity Beamexperiments #12;Wolfram Fischer 10 RHIC Run-41 RHIC Operation and Plans for Upgrades Wolfram Fischer C-AD Machine Advisory Committee Meeting 10

  15. Recent Results from RHIC&Some Lessons for Cosmic-RayPhysicists

    SciTech Connect (OSTI)

    Klein, Spencer R.

    2006-10-01

    The Relativistic Heavy Ion Collider (RHIC) studies nuclear matter under a variety of conditions. Cold nuclear matter is probed with deuteron-gold collisions, while hot nuclear matter (possibly a quark-gluon plasma (QGP)) is created in heavy-ion collisions. The distribution of spin in polarized nucleons is measured with polarized proton collisions, and photoproduction is studied using the photons that accompany heavy nuclei. The deuteron-gold data shows less forward particle production than would be expected from a superposition of pp collisions, as expected due to saturation/shadowing. Particle production in AA collisions is well described by a model of an expanding fireball in thermal equilibrium. Strong hydrodynamic flow and jet quenching shows that the produced matter interacts very strongly. These phenomena are consistent with new non-perturbative interactions near the transition temperature to the QGP. This report discusses these results, and their implications for cosmic-ray physicists.

  16. Estimation of dibaryon (OO) yields at RHIC energies

    E-Print Network [OSTI]

    Zhong-Dao Lu

    2002-07-02

    The yields of dibaryon (Omega-Omega) in relativistic heavy ion collisions, especially at RHIC energies, are estimated by statistical model. The yields of hyperon Omega- and the ratio of dibaryon to Omega are also given.

  17. Weak-strong simulation on head-on beam-beam compensation in the RHIC

    SciTech Connect (OSTI)

    Luo,Y.; Fischer, W.; McIntosh, E.; Robert-Demolaize, G.; Abreu, N.; Beebe-Wang, J.; Montag, C.

    2009-05-04

    In the Relativistic Heavy Ion Collider (RHIC) beams collide in the two interaction points IP6 and IP8. To further increase the bunch intensity above 2 x 10{sup 11} or further reduce the transverse emittance in polarized proton operation, there will not be enough tune space between the current working area [2/3, 7/10] to hold the beam-beam generated tune spread. We proposed a low energy DC electron beam (e-lens) with similar Gaussian transverse profiles to collide with the proton beam at IP10. Early studies have shown that e-lens does reduce the proton-proton beam-beam tune spread. In this article, we carried out numerical simulation to investigate the effects of the head-on beam-beam effect on the proton's colliding beam lifetime and emittance growth. The preliminary results including scans of compensation strength, phase advances between IP8 and IP10, electron beam transverse sizes are presented. In these studies, the particle loss in the multi-particle simulation is used for the comparison between different conditions.

  18. The effect of head-on beam-beam compensation on the stochastic boundaries and particle diffusion in RHIC.

    SciTech Connect (OSTI)

    Abreu,N.; Beebe-Wang, J.; FischW; Luo, Y.; Robert-Demolaize, G.

    2008-06-23

    To compensate the effects from the head-on beam-beam interactions in the polarized proton operation in the Relativistic Heavy Ion Collider (RHIC), an electron lens (elens) is proposed to collide head-on with the proton beam. We used an extended version of SixTrack for multiparticle beam-beam simulation in order to study the effect of the e-lens on the stochastic boundary and also on diffusion. The stochastic boundary was analyzed using Lyapunov exponents and the diffusion was characterized as the increase in the rms spread of the action. For both studies the simulations were performed with and without the e-lens and with full and partial compensation. Using the simulated values of the diffusion an attempt to calculate the emittance growth rate is presented.

  19. Production of Quarkonia at RHIC

    E-Print Network [OSTI]

    Robert Vertesi

    2015-10-02

    The production of different quarkonium states provides unique insight to the hot and cold nuclear matter effects in the strongly interacting medium that is formed in high energy heavy ion collisions. While LHC explores the energy frontier, RHIC has a broad physics program to explore the nuclear modification at different energies in a wide range of systems. Some of the most interesting recent results on $J/\\psi$ and $\\Upsilon$ production in p+p, d+Au and A+A collisions from PHENIX and STAR are summarized in this work.

  20. Soft Physics from RHIC to LHC

    E-Print Network [OSTI]

    Peter Steinberg

    2009-03-09

    The RHIC program was intended to identify and study the quark-gluon plasma formed in the collision of heavy nuclei. The discovery of the "perfect liquid" is an essential step towards the understanding of the medium formed in these collisions. Much of data relevant to this was provided by the study of "soft" observables, which involve many particles of low momentum produced in nearly every event, rather than high momentum particles produced in rare events. The main results related to soft physics at RHIC are discussed, as well as their implications for the physics of the LHC heavy ion program.

  1. Open heavy flavor production at RHIC

    E-Print Network [OSTI]

    A. A. P. Suaide

    2007-02-16

    The study of heavy flavor production in relativistic heavy ion collisions is an extreme experimental challenge but provides important information on the properties of the Quark-Gluon Plasma (QGP) created in Au+Au collisions at RHIC. Heavy-quarks are believed to be produced in the initial stages of the collision, and are essential on the understanding of parton energy loss in the dense medium created in such environment. Moreover, heavy-quarks can help to investigate fundamental properties of QCD in elementary p+p collisions. In this work we review recent results on heavy flavor production and their interaction with the hot and dense medium at RHIC.

  2. Proceedings of RIKEN BNL Resarch Center Workshop: Fluctuations, Correlations and RHIC Low Energy Runs

    SciTech Connect (OSTI)

    Karsch, F.; Kojo, T.; Mukherjee, S.; Stephanov, M.; Xu, N.

    2011-10-27

    Most of our visible universe is made up of hadronic matter. Quantum Chromodynamics (QCD) is the theory of strong interaction that describes the hadronic matter. However, QCD predicts that at high enough temperatures and/or densities ordinary hadronic matter ceases to exist and a new form of matter is created, the so-called Quark Gluon Plasma (QGP). Non-perturbative lattice QCD simulations shows that for high temperature and small densities the transition from the hadronic to the QCD matter is not an actual phase transition, rather it takes place via a rapid crossover. On the other hand, it is generally believed that at zero temperature and high densities such a transition is an actual first order phase transition. Thus, in the temperature-density phase diagram of QCD, the first order phase transition line emanating from the zero temperature high density region ends at some higher temperature where the transition becomes a crossover. The point at which the first order transition line turns into a crossover is a second order phase transition point belonging to three dimensional Ising universality class. This point is known as the QCD Critical End Point (CEP). For the last couple of years the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory has been performing experiments at lower energies in search of the elusive QCD CEP. In general critical behaviors are manifested through appearance of long range correlations and increasing fluctuations associated with the presence of mass-less modes in the vicinity of a second order phase transition. Experimental signatures of the CEP are likely to be found in observables related to fluctuations and correlations. Thus, one of the major focuses of the RHIC low energy scan program is to measure various experimental observables connected to fluctuations and correlations. On the other hand, with the start of the RHIC low energy scan program, a flurry of activities are taking place to provide solid theoretical background for the search of the CEP using observables related to fluctuations and correlations. While new data are pouring in from the RHIC low energy scan program, many recent advances have also been made in the phenomenological and lattice gauge theory sides in order to have a better theoretical understanding of the wealth of new data. This workshop tried to create a synergy between the experimental, phenomenological and lattice QCD aspects of the fluctuation and correlation related studies of the RHIC low energy scan program. The workshop brought together all the leading experts from related fields under the same forum to share new ideas among themselves in order to streamline the continuing search of CEP in the RHIC low energy scan program.

  3. Cryogenic systems for proof of the principle experiment of coherent electron cooling at RHIC

    SciTech Connect (OSTI)

    Huang, Yuenian; Belomestnykh, Sergey; Brutus, Jean Clifford; Lederle, Dewey; Orfin, Paul; Skaritka, John; Soria, Victor; Tallerico, Thomas; Than, Roberto

    2014-01-29

    The Coherent electron Cooling (CeC) Proof of Principle (PoP) experiment is proposed to be installed in the Relativistic Heavy Ion Collider (RHIC) to demonstrate proton and ion beam cooling with this new technique that may increase the beam luminosity in certain cases, by as much as tenfold. Within the scope of this project, a 112 MHz, 2MeV Superconducting Radio Frequency (SRF) electron gun and a 704 MHz 20MeV 5-cell SRF cavity will be installed at IP2 in the RHIC ring. The superconducting RF electron gun will be cooled in a liquid helium bath at 4.4 K. The 704 MHz 5-cell SRF cavity will be cooled in a super-fluid helium bath at 2.0 K. This paper discusses the cryogenic systems designed for both cavities. For the 112 MHz cavity cryogenic system, a condenser/boiler heat exchanger is used to isolate the cavity helium bath from pressure pulses and microphonics noise sources. For the 704 MHz 5-cell SRF cavity, a heat exchanger is also used to isolate the SRF cavity helium bath from noise sources in the sub-atmospheric pumping system operating at room temperature. Detailed designs, thermal analyses and discussions for both systems will be presented in this paper.

  4. A mulitple cathode gun design for the eRHIC polarized electron source

    SciTech Connect (OSTI)

    Chang, X.; Ben-Zvi, I.; Kewisch, J.; Litvinenko, V.; Pikin, A.; Ptitsyn, V.; Rao, T.; Sheehy, B.; Skaritka, J.; Wang, E.; Wu, Q.; Xin, T.

    2011-03-28

    The future electron-ion collider eRHIC requires a high average current ({approx}50 mA), short bunch ({approx}3 mm), low emittance ({approx}20 {micro}m) polarized electron source. The maximum average current of a polarized electron source so far is more than 1 mA, but much less than 50 mA, from a GaAs:Cs cathode. One possible approach to overcome the average current limit and to achieve the required 50 mA beam for eRHIC, is to combine beamlets from multiple cathodes to one beam. In this paper, we present the feasibility studies of this technique. The future eRHIC project, next upgrade of RHIC, will be the first electron-heavy ion collider in the world. It requires polarized electron source with a high average current ({approx}50 mA), short bunch ({approx}3 mm), emittance of about 20 {micro}m and energy spread of {approx}1% at 10 MeV. The state-of-art polarized electron cathode can generate average current of about more than 1 mA, but much less than 50 mA. The current is limited by the low quantum efficiency, space charge and ultra-high vacuum requirement of the polarized cathode. A possible approach to achieve the 50 mA beam is to employ multiple cathodes, such as 20 cathodes, and funnel the multiple bunched beams from cathodes to the same axis. Fig.1 illustrates schematically the concept of combining the multiple beams. We name it as 'Gatling gun' because it bears functional similarity to a Gatling gun. Laser beams strike the cathodes sequentially with revolution frequency of 700 kHz. Each beam bunch is focused by a solenoid and is bent toward the combiner. The combiner with rotating bending field bends all bunches arriving the combiner with a rotational pattern to the same axis. The energy of each bunch is modified by a bunching cavity (112MHz) and a 3rd harmonic cavity (336MHz). The bunch length is compressed ballistically in the drift space and is frozen after energy has been boosted to 10 MeV by the Booster linac. Each beam bunch contains 3.5 nC charge. The space charge is very strong at energy of 200 keV. A long bunch, {sigma} of 250 ps, is adopted to reduce the space charge on cathode. To compress the beam to final length of 3 mm (10 ps) can be achieved by ballistic compression with a 3rd harmonic cavity.

  5. The Shape and Flow of Heavy Ion Collisions (490th Brookhaven Lecture)

    SciTech Connect (OSTI)

    Schenke, Bjoern

    2014-12-18

    The sun can’t do it, but colossal machines like the Relativistic Heavy Ion Collider (RHIC) at Brookhaven Lab and Large Hadron Collider (LHC) in Europe sure can. Quarks and gluons make up protons and neutrons found in the nucleus of every atom in the universe. At heavy ion colliders like RHIC and the LHC, scientists can create matter more than 100,000 times hotter than the center of the sun—so hot that protons and neutrons melt into a plasma of quarks and gluons. The particle collisions and emerging quark-gluon plasma hold keys to understanding how these fundamental particles interact with each other, which helps explain how everything is held together—from atomic nuclei to human beings to the biggest stars—how all matter has mass, and what the universe looked like microseconds after the Big Bang. Dr. Schenke discusses theory that details the shape and structure of heavy ion collisions. He will also explain how this theory and data from experiments at RHIC and the LHC are being used to determine properties of the quark-gluon plasma.

  6. RHIC electron lens test bench diagnostics

    SciTech Connect (OSTI)

    Gassner, D.; Beebe, E.; Fischer, W.; Gu, X.; Hamdi, K.; Hock, J.; Liu, C.; Miller, T.; Pikin, A.; Thieberger, P.

    2011-05-16

    An Electron Lens (E-Lens) system will be installed in RHIC to increase luminosity by counteracting the head-on beam-beam interaction. The proton beam collisions at the RHIC experimental locations will introduce a tune spread due to a difference of tune shifts between small and large amplitude particles. A low energy electron beam will be used to improve luminosity and lifetime of the colliding beams by reducing the betatron tune shift and spread. In preparation for the Electron Lens installation next year, a test bench facility will be used to gain experience with many sub-systems. This paper will discuss the diagnostics related to measuring the electron beam parameters.

  7. Exclusive Vector Meson Production in Relativistic Heavy Ion Collisions

    E-Print Network [OSTI]

    Spencer Klein; Joakim Nystrand

    1999-02-06

    Exclusive vector meson production reactions such as $Au + Au \\to Au + Au + V$, where $V=\\rho, \\omega, \\phi$ or $J/\\psi$ can proceed through photon-Pomeron and photon-meson interactions. Photons from the electromagnetic field of one nucleus interact coherently with the other nucleus. Photonuclear cross sections are scaled from $\\gamma p$ data, and convoluted with the photon spectrum to find the exclusive rates. The cross sections at the RHIC and LHC heavy ion colliders are huge, 10% of the total hadronic cross section at RHIC, and 50% at LHC. These accelerators may be useful as vector meson factories. With iodine beams at RHIC, 640 $\\rho$ are produced each second (10^{10}/year); with calcium at the LHC the rate is 240 kHz. The $\\phi$ rates are 39 Hz at RHIC and 15 kHz at LHC, while the $J/\\psi$ rate is 0.3 Hz at RHIC and 780 Hz at the LHC. Because of the coherent couplings, the reactions kinematics are similar to coherent two-photon interactions; we discuss the interplay between the two reactions.

  8. Experience with IBS-suppression lattice in RHIC

    SciTech Connect (OSTI)

    Litvinenko,V.N.; Luo, Y.; Ptitsyn, V.; Satogata, T.; Tepikian, S.; Bai, M.; Bruno, D.; Cameron, P.; Connolly, R.; Della Penna, A.; Drees, A.; Fedotov, A.; Ganetis, G.; Hoff, L.; Louie, W.; Malitsky, N.; Marr, G.; Marusic, A.; Montag, C.; Pilat, F.; Roser, T.; Trbojevic, D.; Tsoupas, N.

    2008-06-23

    An intra-beam scattering (IBS) is the limiting factor of the luminosity lifetime for RHIC operating with heavy ions. In order to suppress the IBS we designed and implemented new lattice with higher betatron tunes. This lattice had been developed during last three years and had been used for gold ions in yellow ring of the RHIC during d-Au part of the RHIC Run-8. The use of this lattice allowed both significant increases in the luminosity lifetime and the luminosity levels via reduction of beta-stars in the IPS. In this paper we report on the development, the tests and the performance of IBS-suppression lattice in RHIC, including the resulting increases in the peak and the average luminosity. We also report on our plans for future steps with the IBS suppression.

  9. High Precision Tune and Coupling Feedback and Beam Transfer Function Measurements in RHIC

    SciTech Connect (OSTI)

    Minty, M.; Curcio, A.; Dawson, C.; Degen, C.; Luo, Y.; Marr, G.; Martin, B.; Marusic, A.; Mernick, K.; Oddo, P.; Russo, T.; Schoefer, V.; Schroeder, R.; Schultheiss, C.; Wilinski, M.

    2010-05-23

    Precision measurement and control of the betatron tunes and betatron coupling in the Relativistic Heavy Ion Collider (RHIC) are required for establishing and maintaining both good operating conditions and, particularly during the ramp to high beam energies, high proton beam polarization. While the proof-of-principle for simultaneous tune and coupling feedback was successfully demonstrated earlier, routine application of these systems has only become possible recently. Following numerous modifications for improved measurement resolution and feedback control, the time required to establish full-energy beams with the betatron tunes and coupling regulated by feedback was reduced from several weeks to a few hours. A summary of these improvements, select measurements benefitting from the improved resolution and a review of system performance are the subject of this report.

  10. Understanding the composition of nucleon spin with the PHENIX detector at RHIC

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Deshpande, Abhay

    2015-01-12

    The Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL) has just finished 14 years of operation. A significant fraction of these operating years were with polarized proton collisions at 62.4, 200, and 500 GeV center of mass, investigating various aspects of nucleon spin through longitudinal and transversely polarized collisions. These data have helped to address some of the most puzzling and fundamental questions in quantum chromodynamics including: what fraction of the nucleon’s spin originates in the gluon’s helicity contribution?, how polarized are the sea quarks?, and what if any, is the evidence for transverse motion of quarks inmore »polarized protons? These questions have been addressed by the PHENIX detector collaboration. We present in this review highlights of the PHENIX results and discuss their impact.« less

  11. Charmed hadron production at low transverse momentum in Au+Au collisions at RHIC

    E-Print Network [OSTI]

    B. I. Abelev

    2014-04-25

    We report measurements of charmed hadron production from hadronic ($D^{0}\\rightarrow K\\pi$) and semileptonic ($\\mu$ and $e$) decays in 200 GeV Au+Au collisions at RHIC. Analysis of the spectra indicates that charmed hadrons have a different radial flow pattern from light or multi-strange hadrons. Charm cross sections at mid-rapidity are extracted by combining the three independent measurements, covering the transverse momentum range that contributes to $\\sim$90% of the integrated cross section. The cross sections scale with number of binary collisions of the initial nucleons, a signature of charm production exclusively at the initial impact of colliding heavy ions. The implications for charm quark interaction and thermalization in the strongly interacting matter are discussed.

  12. Ballistic protons in incoherent exclusive vector meson production as a measure of rare parton fluctuations at an electron-ion collider

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Lappi, T.; Venugopalan, R.; Mantysaari, H.

    2015-02-25

    We argue that the proton multiplicities measured in Roman pot detectors at an electron ion collider can be used to determine centrality classes in incoherent diffractive scattering. Incoherent diffraction probes the fluctuations in the interaction strengths of multi-parton Fock states in the nuclear wavefunctions. In particular, the saturation scale that characterizes this multi-parton dynamics is significantly larger in central events relative to minimum bias events. As an application, we examine the centrality dependence of incoherent diffractive vector meson production. We identify an observable which is simultaneously very sensitive to centrality triggered parton fluctuations and insensitive to details of the model.

  13. Electromagnetic interactions at RHIC and LHC

    E-Print Network [OSTI]

    M. C. Guclu

    2008-11-15

    At LHC energies the Lorentz factor will be 3400 for the Pb + Pb collisions and the electromagnetic interactions will play important roles. Cross sections for the electromagnetic particle productions are very large and can not be ignored for the lifetimes of the beams and background. In this article, we are going to study some of the electromagnetic processes at RHIC and LHC and show the cross section calculations of the electron-positron pair production with the giant dipole resonance of the ions.

  14. The reconstructed Big Bang from RHIC data

    E-Print Network [OSTI]

    A. Ster; T. Csorgo

    2001-12-04

    The final state of $Au + Au$ collisions at sqrt{s}=130 AGeV at RHIC has been reconstructed within the framework of the Buda-Lund hydro model, by performing a simultaneous fit to preliminary PHENIX and STAR data on two-particle Bose-Einstein correlations and identified single particle spectra. The Hubble constant of the expanding final state of this heavy ion collision is determined to be H = = 0.77 +- 0.09.

  15. The Hot QCD White Paper: Exploring the Phases of QCD at RHIC and the LHC

    E-Print Network [OSTI]

    Yasuyuki Akiba; Aaron Angerami; Helen Caines; Anthony Frawley; Ulrich Heinz; Barbara Jacak; Jiangyong Jia; Tuomas Lappi; Wei Li; Abhijit Majumder; David Morrison; Mateusz Ploskon; Joern Putschke; Krishna Rajagopal; Ralf Rapp; Gunther Roland; Paul Sorensen; Urs Wiedemann; Nu Xu; W. A. Zajc

    2015-02-09

    The past decade has seen huge advances in experimental measurements made in heavy ion collisions at the Relativistic Heavy Ion Collider (RHIC) and more recently at the Large Hadron Collider (LHC). These new data, in combination with theoretical advances from calculations made in a variety of frameworks, have led to a broad and deep knowledge of the properties of thermal QCD matter. Increasingly quantitative descriptions of the quark-gluon plasma (QGP) created in these collisions have established that the QGP is a strongly coupled liquid with the lowest value of specific viscosity ever measured. However, much remains to be learned about the precise nature of the initial state from which this liquid forms, how its properties vary across its phase diagram and how, at a microscopic level, the collective properties of this liquid emerge from the interactions among the individual quarks and gluons that must be visible if the liquid is probed with sufficiently high resolution. This white paper, prepared by the Hot QCD Writing Group as part of the U.S. Long Range Plan for Nuclear Physics, reviews the recent progress in the field of hot QCD and outlines the scientific opportunities in the next decade for resolving the outstanding issues in the field.

  16. First Hints of Jet Quenching at RHIC

    E-Print Network [OSTI]

    A. Drees

    2001-05-25

    At this conference first data from RHIC has been presented. Spectra of charged hadrons and identified neutral pions obtained in central collisions exhibit a depletion at large transverse momenta compared to expectations deduced from $pp$ and $\\bar{p}p$ data and lower energy heavy ion data. While spectra measured in peripheral collisions exhibit the expected power-law shape, spectra from central collisions are closer to exponential. In addition, a significant azimuthal anisotropy of high momentum charged particle production has been found. All observations are in qualitative agreement with theoretical predictions that quark matter formed in heavy ion collisions quenches jet production.

  17. THE TWO STAGE CRYSTAL COLLIMATOR FOR RHIC.

    SciTech Connect (OSTI)

    FLILLER, R.P. III; DREES, A.; GASSNER, D.; HAMMONS, L.; MCINTYRE, G.; TRBOJEVIC, D.; BIRYUKOV, V.; CHESNOKOV, Y.; TEREKHOV, V.

    2001-06-18

    The use of a two stage crystal collimation system in the RHIC yellow ring is examined. The system includes a copper beam scraper and a bent silicon crystal. While scrapers were installed in both of the RHIC rings before the year 2000 run, the crystal is installed for the 2001 run in one ring only, forming a two stage collimation system there. We present simulations of the expected channeling through the bent silicon crystal for both protons and gold ions with various beam parameters. This gives a picture of the particle losses around the ring, and the expected channeling efficiency. These results are then used to optimize the beam parameters in the area of the crystal to obtain maximum channeling efficiency, minimize out-scattering in the secondary collimator, and reduce beam halo.

  18. PHENIX CDR update: An experiment to be performed at the Brookhaven National Laboratory relativistic heavy ion collider. Revision

    SciTech Connect (OSTI)

    Not Available

    1994-11-01

    The PHENIX Conceptual Design Report Update (CDR Update) is intended for use together with the Conceptual Design Report (CDR). The CDR Update is a companion document to the CDR, and it describes the collaboration`s progress since the CDR was submitted in January 1993. Therefore, this document concentrates on changes, refinements, and decisions that have been made over the past year. These documents together define the baseline PHENIX detector that the collaboration intends to build for operation at RHIC startup. In this chapter the current status of the detector and its motivation are briefly described. In Chapters 2 and 3 the detector and the physics performance are more fully developed. In Chapters 4 through 13 the details of the present design status, the technology choices, and the construction costs and schedules are presented. The physics goals of PHENIX collaboration have remained exactly as they were described in the CDR. Primary among these is the detection of a new phase of matter, the quark-gluon plasma (QGP), and the measurement of its properties. The PHENIX experiment will measure many of the best potential QGP signatures to see if any or all of these physics variables show anomalies simultaneously due to the formation of the QGP.

  19. Beam-Energy Dependence of Charge Balance Functions from Au+Au Collisions at RHIC

    E-Print Network [OSTI]

    STAR Collaboration

    2015-07-13

    Balance functions have been measured in terms of relative pseudorapidity ($\\Delta \\eta$) for charged particle pairs at the Relativistic Heavy-Ion Collider (RHIC) from Au+Au collisions at $\\sqrt{s_{\\rm NN}}$ = 7.7 GeV to 200 GeV using the STAR detector. These results are compared with balance functions measured at the Large Hadron Collider (LHC) from Pb+Pb collisions at $\\sqrt{s_{\\rm NN}}$ = 2.76 TeV by the ALICE Collaboration. The width of the balance function decreases as the collisions become more central and as the beam energy is increased. In contrast, the widths of the balance functions calculated using shuffled events show little dependence on centrality or beam energy and are larger than the observed widths. Balance function widths calculated using events generated by UrQMD are wider than the measured widths in central collisions and show little centrality dependence. The measured widths of the balance functions in central collisions are consistent with the delayed hadronization of a deconfined quark gluon plasma (QGP). The narrowing of the balance function in central collisions at $\\sqrt{s_{\\rm NN}}$ = 7.7 GeV implies that a QGP is still being created at this relatively low energy.

  20. Beam-Energy Dependence of Charge Balance Functions from Au+Au Collisions at RHIC

    E-Print Network [OSTI]

    ,

    2015-01-01

    Balance functions have been measured in terms of relative pseudorapidity ($\\Delta \\eta$) for charged particle pairs at the Relativistic Heavy-Ion Collider (RHIC) from Au+Au collisions at $\\sqrt{s_{\\rm NN}}$ = 7.7 GeV to 200 GeV using the STAR detector. These results are compared with balance functions measured at the Large Hadron Collider (LHC) from Pb+Pb collisions at $\\sqrt{s_{\\rm NN}}$ = 2.76 TeV by the ALICE Collaboration. The width of the balance function decreases as the collisions become more central and as the beam energy is increased. In contrast, the widths of the balance functions calculated using shuffled events show little dependence on centrality or beam energy and are larger than the observed widths. Balance function widths calculated using events generated by UrQMD are wider than the measured widths in central collisions and show little centrality dependence. The measured widths of the balance functions in central collisions are consistent with the delayed hadronization of a deconfined quark g...

  1. Heavy-flavor production in heavy-ion collisions and implications for the properties of hot QCD matter

    E-Print Network [OSTI]

    R. Averbeck

    2015-05-14

    Hadrons carrying open heavy flavor, i.e. single charm or bottom quarks, are among the key diagnostic tools available today for the hot and dense state of strongly interacting matter which is produced in collisions of heavy atomic nuclei at ultra-relativistic energies. First systematic heavy-flavor measurements in nucleus-nucleus collisions and the reference proton-proton system at Brookhaven National Laboratory's (BNL) Relativistic Heavy Ion Collider (RHIC) have led to tantalizing results. These studies are now continued and extended at RHIC and at CERN's Large Hadron Collider (LHC), where considerably higher collision energies are available. This review focuses on experimental results on open heavy-flavor observables at RHIC and the LHC published until July 2012. Yields of heavy-flavor hadrons and their decay products, their transverse momentum and rapidity distributions, as well as their azimuthal distributions with respect to the reaction plane in heavy-ion collisions are investigated. Various theoretical approaches are confronted with the data and implications for the properties of the hot and dense medium produced in ultra-relativistic heavy-ion collisions are discussed.

  2. The PHOBOS Perspective on Discoveries at RHIC

    E-Print Network [OSTI]

    B. B. Back et al

    2005-03-28

    This paper describes the conclusions that can be drawn from the data taken thus far with the PHOBOS detector at RHIC. In the most central Au+Au collisions at the highest beam energy, evidence is found for the formation of a very high energy density system whose description in terms of simple hadronic degrees of freedom is inappropriate. Furthermore, the constituents of this novel system are found to undergo a significant level of interaction. The properties of particle production at RHIC energies are shown to follow a number of simple scaling behaviors, some of which continue trends found at lower energies or in simpler systems. As a function of centrality, the total number of charged particles scales with the number of participating nucleons. When comparing Au+Au at different centralities, the dependence of the yield on the number of participants at higher pT (~4 GeV/c) is very similar to that at low transverse momentum. The measured values of charged particle pseudorapidity density and elliptic flow were found to be independent of energy over a broad range of pseudorapidities when effectively viewed in the rest frame of one of the colliding nuclei, a property we describe as "extended longitudinal scaling''. Finally, the centrality and energy dependences of several observables were found to factorize to a surprising degree.

  3. Particle production at RHIC energies

    E-Print Network [OSTI]

    R. Debbe; for the BRAHMS collaboration

    2003-08-06

    This paper presents recent results from the BRAHMS experiment at RHIC; including results on particle production in rapidity space extending from y=0 to y ~ 3 and on the transverse momentum distribution of fully identified charged particles. These results were obtained from the 5% most central Au-Au collisions recorded during RHIC Run-2 at sqrt{s_{NN}} = 200 GeV.

  4. Anion emission from water molecules colliding with positive ions: Identification of binary and many-body processes

    E-Print Network [OSTI]

    Chesnel, J -Y; Lattouf, E; Tanis, J A; Huber, B A; Bene, E; Kovács, S T S; Herczku, P; Méry, A; Poully, J -C; Rangama, J; Sulik, B

    2015-01-01

    It is shown that negative ions are ejected from gas-phase water molecules when bombarded with positive ions at keV energies typical of solar-wind velocities. This finding is relevant for studies of planetary and cometary atmospheres, as well as for radiolysis and radiobiology. Emission of both H- and heavier (O- and OH-) anions, with a larger yield for H-, was observed in 6.6-keV 16O+ + H2O collisions. The ex-perimental setup allowed separate identification of anions formed in collisions with many-body dynamics from those created in hard, binary collisions. Most of the ani-ons are emitted with low kinetic energy due to many-body processes. Model calcu-lations show that both nucleus-nucleus interactions and electronic excitations con-tribute to the observed large anion emission yield.

  5. Future Possibilities for Lepton-Hadron Collider Physics and Detectors

    E-Print Network [OSTI]

    Fleming, G; Lammers, S; Magill, S

    2001-01-01

    We have considered the physics opportunities of future lepton-hadron colliders and how these opportunities might be realized in a possible polarized eRHIC facility and an e-p collider as part of a staged or final version VLHC. We evaluated the physics priorities based on experience at HERA and, using simulated data for e-p collisions with sqrt(s) > 1 TeV, showed how detector designs would be impacted by the physics.

  6. Future Possibilities for Lepton-Hadron Collider Physics and Detectors

    E-Print Network [OSTI]

    G. Fleming; E. Kinney; S. Lammers; S. Magill

    2002-01-29

    We have considered the physics opportunities of future lepton-hadron colliders and how these opportunities might be realized in a possible polarized eRHIC facility and an e-p collider as part of a staged or final version VLHC. We evaluated the physics priorities based on experience at HERA and, using simulated data for e-p collisions with sqrt(s) > 1 TeV, showed how detector designs would be impacted by the physics.

  7. Commissioning of the EBIS-based heavy ion preinjector at Brookhaven

    SciTech Connect (OSTI)

    Alessi, J.; Beebe, E.; Binello, S.; Hoff, L.; Kondo, K.; Lambiase, R.; LoDestro, V.; Mapes, M.; McNerney, A.; Morris, J.; Okamura, M.; Pikin, A.I.; Raparia, D.; Ritter, J.; Smart, L.; Snydstrup, L.; Wilinski, M.; Zaltsman, A.; Schempp, A.; Ratzinger, U.; Kanesue, T.

    2010-09-12

    The status is presented of the commissioning of a new heavy ion preinjector at Brookhaven National Laboratory. This preinjector uses an Electron Beam Ion Source (EBIS), and an RFQ and IH Linac, both operating at 100.625 MHz, to produce 2 MeV/u ions of any species for use, after further acceleration, at the Relativistic Heavy Ion Collider (RHIC) and the NASA Space Radiation Laboratory (NSRL). Among the increased capabilities provided by this preinjector are the ability to produce ions of any species, and the ability to switch between multiple species in 1 second, to simultaneously meet the needs of both science programs. For initial setup, helium beam from EBIS was injected and circulated in the Booster synchrotron. Following this, accelerated Au{sup 32+} and Fe{sup 20+} beams were transported to the Booster injection point, fulfilling DOE requirements for project completion.

  8. Charged hadron transverse momentum spectra in Au+Au and d+Au collisions at 200 GeV per nucleon pair

    E-Print Network [OSTI]

    Kane, Jay Lawrence

    2005-01-01

    The Relativistic Heavy Ion Collider (RHIC) collides Au ions at a center of mass energy of 200 GeV per nucleon pair, which produces the most energetic collisions yet seen in the laboratory. RHIC has also collided proton ...

  9. RHIC PHYSICS: THE QUARK GLUON PLASMA AND THE COLOR GLASS CONDENSATE: 4 LECTURES

    SciTech Connect (OSTI)

    MCLERRAN,L.

    2003-01-01

    The purpose of these lectures is to provide an introduction to the physics issues which are being studied in the RHIC heavy ion program. These center around the production of new states of matter. The Quark Gluon Plasma is thermal matter which once existed in the big bang which may be made at RHIC. The Color Glass Condensate is a universal form of matter which controls the high energy limit of strong interactions. Both such forms of matter might be produced and probed at RHIC.

  10. R2D - The Case for a Comprehensive New RHIC-II Detector

    E-Print Network [OSTI]

    R. Bellwied

    2005-10-05

    A new detector concept (R2D) is needed to harvest the unique physics opportunities at RHIC-II during the LHC era. This concept is based on a high granularity hermetic array of detectors featuring high momentum particle identification and superior resolution for photon and onium measurements. Most components of R2D can also be applied to future electron-ion interactions. Thus, R2D allows us to perform precision QCD-type measurements at RHIC-II and eRHIC.

  11. R2D - The Case for a Comprehensive New RHIC-II Detector

    E-Print Network [OSTI]

    Bellwied, R

    2006-01-01

    A new detector concept (R2D) is needed to harvest the unique physics opportunities at RHIC-II during the LHC era. This concept is based on a high granularity hermetic array of detectors featuring high momentum particle identification and superior resolution for photon and onium measurements. Most components of R2D can also be applied to future electron-ion interactions. Thus, R2D allows us to perform precision QCD-type measurements at RHIC-II and eRHIC.

  12. Muon Collider

    SciTech Connect (OSTI)

    Palmer, R.

    2009-10-19

    Parameters are given of muon colliders with center of mass energies of 1.5 and 3 TeV. Pion production is from protons on a mercury target. Capture, decay, and phase rotation yields bunch trains of both muon signs. Six dimensional cooling reduces the emittances until the trains are merged into single bunches, one of each sign. Further cooling in 6 dimensions is then applied, followed by final transverse cooling in 50 T solenoids. After acceleration the muons enter the collider ring. Ongoing R&D is discussed.

  13. Azimuthal anisotropy and fundamental symmetries in QCD matter at RHIC

    E-Print Network [OSTI]

    V. A. Okorokov

    2008-09-18

    A study of collective behavior in heavy ion collisions provides one of the most sensitive and promising probes for investigation of possible formation of new extreme state of strong interacting matter and elucidating its properties. Systematic of experimental results for final state azimuthal anisotropy is presented for heavy ion interactions at RHIC. Experimental data for azimuthal anisotropy indicate that the final state strongly interacting matter under extreme conditions behaves as near-ideal liquid rather, than ideal gas of quarks and gluons. The strong quenching of jets and the dramatic modification of jet-like azimuthal correlations, observed in ${Au+Au}$ collisions, are evidences of the extreme energy loss of partons traversing matter which contains a large density of color charges. For the first time, dependence of the jet suppression on orientation of a jet with respect to the reaction plane is found at RHIC experimentally. The model of compound collective flow and corresponding analytic approach are discussed. The possible violations of $\\cal{P}$ and $\\cal{CP}$ symmetries of strong interactions in heavy ion collisions at different initial energies are considered. Thus, now the fact is established firmly, that extremely hot and dense matter created in relativistic heavy ion collisions at RHIC differs dramatically from everything that was observed and investigated before.

  14. Research and development of RHIC injection kicker upgrade with nano second FID pulse generator

    SciTech Connect (OSTI)

    Zhang W.; Sandberg, J.; Hahn, H.; Fischer, W.; Liaw, C.J.; Pai, C.; Tuozzolo, J.

    2012-05-20

    Our recent effort to test a 50 kV, 1 kA, 50 ns pulse width, 10 ns pulse rise time FID pulse generator with a 250 ft transmission cable, resistive load, and existing RHIC injection kicker magnet has produced unparalleled results. This is the very first attempt to drive a high strength fast kicker magnet with a nano second high pulsed power (50 MVA) generator for large accelerator and colliders. The technology is impressive. We report here the result and future plan of RHIC Injection kicker upgrade.

  15. Rapidity Dependence of $J/?$ Production at RHIC and LHC

    E-Print Network [OSTI]

    Yunpeng Liu; Zhen Qu; Nu Xu; Pengfei Zhuang

    2009-07-16

    The motion of charmonium in heavy ion collisions is described by a three dimensional transport equation with initial production and continuous regeneration in hot medium. The observation of apparently stronger $J/\\psi$ suppression at forward rapidity compared to that at midrapidity, so called $J/\\psi$ puzzle at RHIC, can well be explained by the competition between the two production mechanisms. At LHC, however, the rapidity dependence of the $J/\\psi$ production is dominated by the regeneration process.

  16. Transverse profile of the electron beam for the RHIC electron lenses

    SciTech Connect (OSTI)

    Gu, X.; Altinbas, Z.; Costanzo, M.; Fischer, W.; Gassner, D. M.; Hock, J.; Luo, Y.; Miller, T.; Tan, Y.; Thieberger, P.; Montag, C.; Pikin, A. I.

    2015-07-10

    To compensate for the beam-beam effects from the proton-proton interactions at the two interaction points IP6 and IP8 in the Relativistic Heavy Ion Collider (RHIC), we are constructing two electron lenses (e-lenses) that we plan to install in the interaction region IR10. Before installing them, the electron gun, collector, instrumentation were tested and the electron beam properties were qualified on an electron lens test bench. We will present the test results and discuss our measurement of the electron beam current and of the electron gun perveance. We achieved a maximum current of 1 A with 5 kV energy for both the pulsed- and the DC-beam (which is a long turn-by-turn pulse beam). We measured beam transverse profiles with an Yttrium Aluminum Garnet (YAG) screen and pinhole detector, and compared those to simulated beam profiles. Measurements of the pulsed electron beam stability were obtained by measuring the modulator voltage.

  17. Transverse profile of the electron beam for the RHIC electron lenses

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Gu, X.; Altinbas, Z.; Costanzo, M.; Fischer, W.; Gassner, D. M.; Hock, J.; Luo, Y.; Miller, T.; Tan, Y.; Thieberger, P.; et al

    2015-07-10

    To compensate for the beam-beam effects from the proton-proton interactions at the two interaction points IP6 and IP8 in the Relativistic Heavy Ion Collider (RHIC), we are constructing two electron lenses (e-lenses) that we plan to install in the interaction region IR10. Before installing them, the electron gun, collector, instrumentation were tested and the electron beam properties were qualified on an electron lens test bench. We will present the test results and discuss our measurement of the electron beam current and of the electron gun perveance. We achieved a maximum current of 1 A with 5 kV energy for bothmore »the pulsed- and the DC-beam (which is a long turn-by-turn pulse beam). We measured beam transverse profiles with an Yttrium Aluminum Garnet (YAG) screen and pinhole detector, and compared those to simulated beam profiles. Measurements of the pulsed electron beam stability were obtained by measuring the modulator voltage.« less

  18. On pseudorapidity distribution and speed of sound in high energy heavy ion collisions based on a new revised Landau hydrodynamic model

    E-Print Network [OSTI]

    Gao, Li-Na

    2015-01-01

    We propose a new revised Landau hydrodynamic model to study systematically the pseudorapidity distributions of charged particles produced in heavy ion collisions over an energy range from a few GeV to a few TeV per nucleon pair. The interacting system is divided into three sources namely the central, target, and projectile sources respectively. The large central source is described by the Landau hydrodynamic model and further revised by the contributions of the small target/projectile sources. In the calculation, to avoid the errors caused by an unapt conversion or non-division, the rapidity and pseudorapidity distributions are obtained respectively. The modeling results are in agreement with the available experimental data at relativistic heavy ion collider (RHIC), large hadron collider (LHC), and other energies for different centralities. The value of square speed of sound parameter in different collisions has been extracted by us from the widths of rapidity distributions. Our results show that, in heavy io...

  19. QGP time formation in holographic shock waves model of heavy ion collisions

    E-Print Network [OSTI]

    Aref'eva, Irina Ya

    2015-01-01

    We estimate the thermalization time in two colliding shock waves holographic model of heavy-ion collisions. For this purpose we model the process by the Vaidya metric with a horizon defined by the trapped surface location. We consider two bottom-up AdS/QCD models that give, within the colliding shock waves approach, the dependence of multiplicity on the energy compatible with RHIC and LHC results. One model is a bottom-up AdS/QCD confining model and the other is related to an anisotropic thermalization. We estimate the thermalization time and show that increasing the confining potential decreases the thermalization time as well as an anisotropy accelerates the thermalization.

  20. QGP time formation in holographic shock waves model of heavy ion collisions

    E-Print Network [OSTI]

    Irina Ya. Aref'eva

    2015-03-07

    We estimate the thermalization time in two colliding shock waves holographic model of heavy-ion collisions. For this purpose we model the process by the Vaidya metric with a horizon defined by the trapped surface location. We consider two bottom-up AdS/QCD models that give, within the colliding shock waves approach, the dependence of multiplicity on the energy compatible with RHIC and LHC results. One model is a bottom-up AdS/QCD confining model and the other is related to an anisotropic thermalization. We estimate the thermalization time and show that increasing the confining potential decreases the thermalization time as well as an anisotropy accelerates the thermalization.

  1. Transverse Energy Production at RHIC

    E-Print Network [OSTI]

    Qun Li; Yang Pang; Nu Xu

    1999-06-18

    We study the mechanism of transverse energy (E_T) production in Au+Au collisions at RHIC. The time evolution starting from the initial energy loss to the final E_T production is closely examined in transport models. The relationship between the experimentally measured E_T distribution and the maximum energy density achieved is discussed.

  2. Open Charm Production at RHIC

    E-Print Network [OSTI]

    Xin Dong

    2005-09-30

    Recent experimental measurements on open charm production in proton-proton, proton (deuteron)-nucleus and nucleus-nucleus collisions at RHIC are reviewed. A comparison with theoretical predictions is made. Some unsettled issues in open charm production call for precise measurements on directly reconstructed open charm hadrons.

  3. Cryogenic sub-system for the 56 MHz SRF storage cavity for RHIC

    SciTech Connect (OSTI)

    Huang, Y.; Than, R.; Orfin, P.; Lederle, D.; Tallerico, T.; Masi L.; Talty, P.; Zhang, Y.

    2011-03-28

    A 56 MHz Superconducting RF Storage Cavity is being constructed for the RHIC collider. This cavity is a quarter wave resonator that will be operated in a liquid helium bath at 4.4 K. The cavity requires an extremely quiet environment to maintain its operating frequency. The cavity, besides being engineered for a mechanically quiet system, also requires a quiet cryogenic system. The helium is taken from RHIC's main helium supply header at 3.5 atm, 5.3K at a phase separator tank. The boil-off is sent back to the RHIC refrigeration system to recover the cooling. To acoustically separate the RHIC helium supply and return lines, a condenser/boiler heat exchanger condenses the helium vapor generated in the RF cavity bath. A system description and operating parameters are given about the cryogen delivery system. The 56 MHz superconducting storage RF cavity project is making progress. The cryogenic system design is in its final stage. The helium supply lines have been tapped into the RHIC helium distribution lines. The plate-and-fin heat exchanger design is near completion and specification will be sent out for bid soon. The cold helium vapor heating system design will start soon as well. A booster compressor specification is underway. The first phase separator and transfer line design work is near completion and will be sent out for bid soon.

  4. NSAC Subcommittee on RHI RHIC Spin: Experimental Issues BNL, June 3rd 2004 RHIC SPIN: Experimental Issues

    E-Print Network [OSTI]

    Ohta, Shigemi

    NSAC Subcommittee on RHI RHIC Spin: Experimental Issues BNL, June 3rd 2004 RHIC SPIN: Experimental Subcommittee on RHI RHIC Spin: Experimental Issues BNL, June 3rd 2004 Spin Physics at RHIC o Spin Structure Subcommittee on RHI RHIC Spin: Experimental Issues BNL, June 3rd 2004 Parton Distribution functions (PDF

  5. Spin Physics Program at RHIC-PHENIX

    E-Print Network [OSTI]

    K. Aoki; for the PHENIX Collaboration

    2007-09-03

    Longitudinal spin physics program at RHIC-PHENIX is introduced. Recent results of pi0 cross section and A_LL are presented and discussed.

  6. Ultra-Peripheral Collisions at RHIC

    E-Print Network [OSTI]

    Joakim Nystrand

    2008-01-23

    This presentation summarizes the results on ultra-peripheral collisions obtained at RHIC. It also discusses some aspects of the corresponding electromagnetic interactions in pp and pbarp collisions.

  7. Eccentricity fluctuations from the Color Glass Condensate at RHIC and LHC

    E-Print Network [OSTI]

    H. -J. Drescher; Y. Nara

    2007-07-02

    In this brief note, we determine the fluctuations of the initial eccentricity in heavy-ion collisions caused by fluctuations of the nucleon configurations. This is done via a Monte-Carlo implementation of a Color Glass Condensate $k_t$-factorization approach. The eccentricity fluctuations are found to nearly saturate elliptic flow fluctuations measured recently at RHIC. Extrapolations to LHC energies are shown.

  8. Conference on the Intersections of Particle and Nuclear Physics 2003: Relativistic Heavy Ion Parallel Session Summary

    E-Print Network [OSTI]

    J. L. Nagle; T. Hallman

    2003-08-19

    The Relativistic Heavy Ion Collider (RHIC) came online in 2000, and the last three years have provided a wealth of new experimental data and theoretical work in this new energy frontier for nuclear physics. The transition from quarks and gluons bound into hadrons to a deconfined quark-gluon plasma is expected to occur at these energies, and the effort to understand the time evolution of these complex systems has been significantly advanced. The heavy ion parallel session talks from the Conference on the Intersections of Particle and Nuclear Physics (CIPANP) 2003 are posted at: http://www.phenix.bnl.gov/WWW/publish/nagle/CIPANP/. We provide a brief summary of these sessions here.

  9. System size and energy dependence of $?$ meson production at RHIC

    E-Print Network [OSTI]

    J. H. Chen

    2008-04-28

    We present a system size and energy dependence of $\\phi$ meson production in Cu+Cu and Au+Au collisions at $\\sqrt{s_{NN}}$=62.4 GeV and 200 GeV measured by the STAR experiment at RHIC. We find that the number of participant scaled $\\phi$ meson yields in heavy ion collisions over that of p+p collisions are larger than 1 and increase with collision energy. We compare the results with those of open-strange particles and discuss the physics implication.

  10. COLLECTIVE EFFECTS IN THE RHIC-II ELECTRON COOLER

    SciTech Connect (OSTI)

    POZDEYEV,E.; BEN-ZVI, I.; FEDOTOV, A.; KAYRAN, D.; LITVINENKO, V.; WANG, G.

    2007-06-25

    Electron cooling at RHIC-I1 upgrade imposes strict requirements on the quality of the electron beam at the cooling section. Beam current dependent effects such as the space charge, wake fields, CSR in bending magnets, trapped ions, etc., will tend to spoil the beam quality and decrease the cooling efficiency. In this paper, we estimate the defocusing effect of the space charge at the cooling section and describe our plan to compensate the defocusing space charge force by focusing solenoids. We also estimate the energy and emittance growth cased by wake fields. Finally, we discuss ion trapping in the electron cooler and consider different techniques to minimize the effect of ion trapping.

  11. Photons and Exclusive Processes at Hadron Colliders

    E-Print Network [OSTI]

    Joakim Nystrand

    2010-01-26

    The theoretical and experimental aspects of particle production from the strong equivalent photon fluxes present at high energy hadron colliders are reviewed. The goal is to show how photons at hadron colliders can improve what we have learnt from experiments with lepton beams. Experiments during the last 5-10 years have shown the feasibility of studying photoproduction in proton-proton and heavy-ion collisions. The experimental and theoretical development has revealed new opportunities as well as challenges.

  12. ? production as a probe for early state dynamics in high energy nuclear collisions at RHIC

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Liu, Yunpeng; Chen, Baoyi; Xu, Nu; Zhuang, Pengfei

    2011-02-01

    ? production in heavy ion collisions at RHIC energy is investigated. While the transverse momentum spectra of the ground state ?(1s) are controlled by the initial state Cronin effect, the excited bb? states are characterized by the competition between the cold and hot nuclear matter effects and sensitive to the dissociation temperatures determined by the heavy quark potential. We emphasize that it is necessary to measure the excited heavy quark states in order to extract the early stage information in high energy nuclear collisions at RHIC.

  13. Optics measurements and corrections at RHIC

    SciTech Connect (OSTI)

    Bai M.; Aronson, J.; Blaskiewicz, M.; Luo, Y.; Robert-Demolaize, G.; White, S.

    2012-05-20

    The further improvement of RHIC luminosity performance requires more precise understanding of the RHIC modeling. Hence, it is necessary to minimize the beta-beat, deviation of measured beta function from the calculated beta functions based on an model. The correction of betabeat also opens up the possibility of exploring operating RHIC polarized protons at a working point near integer, a prefered choice for both luminosity as well as beam polarization. The segment-by-segment technique for reducing beta-beat demonstrated in the LHC operation for reducing the beta-beat was first tested in RHIC during its polarized proton operation in 2011. It was then fully implemented during the RHIC polarized proton operation in 2012. This paper reports the commissioning results. Future plan is also presented.

  14. Hadron Production in Heavy Ion Collisions

    E-Print Network [OSTI]

    Helmut Oeschler; Hans Georg Ritter; Nu Xu

    2009-08-12

    We review hadron production in heavy ion collisions with emphasis on pion and kaon production at energies below 2 AGeV and on partonic collectivity at RHIC energies.

  15. Review of Current FFAG Lattice Studies in North America

    E-Print Network [OSTI]

    2004-01-01

    and V. Ptitsyn, eds. , “eRHIC Zero th -Order Design Report,”Electron Acceleration for eRHIC with non-Scaling FFAG,” topasses through the RF. The eRHIC electron-ion collider [5

  16. System size dependence of transverse momentum correlations at $\\sqrt{s_{NN}}=$ 62.4 and 200 GeV at the BNL Relativistic Heavy Ion Collider

    E-Print Network [OSTI]

    STAR Collaboration; L. Adamczyk; J. K. Adkins; G. Agakishiev; M. M. Aggarwal; Z. Ahammed; I. Alekseev; J. Alford; C. D. Anson; A. Aparin; D. Arkhipkin; E. Aschenauer; G. S. Averichev; J. Balewski; A. Banerjee; Z. Barnovska; D. R. Beavis; R. Bellwied; M. J. Betancourt; R. R. Betts; A. Bhasin; A. K. Bhati; Bhattarai; H. Bichsel; J. Bielcik; J. Bielcikova; L. C. Bland; I. G. Bordyuzhin; W. Borowski; J. Bouchet; A. V. Brandin; S. G. Brovko; E. Bruna; S. Bültmann; I. Bunzarov; T. P. Burton; J. Butterworth; H. Caines; M. Calderón de la Barca Sánchez; D. Cebra; R. Cendejas; M. C. Cervantes; P. Chaloupka; Z. Chang; S. Chattopadhyay; H. F. Chen; J. H. Chen; J. Y. Chen; L. Chen; J. Cheng; M. Cherney; A. Chikanian; W. Christie; P. Chung; J. Chwastowski; M. J. M. Codrington; R. Corliss; J. G. Cramer; H. J. Crawford; X. Cui; S. Das; A. Davila Leyva; L. C. De Silva; R. R. Debbe; T. G. Dedovich; J. Deng; R. Derradi de Souza; S. Dhamija; B. di Ruzza; L. Didenko; Dilks; F. Ding; A. Dion; P. Djawotho; X. Dong; J. L. Drachenberg; J. E. Draper; C. M. Du; L. E. Dunkelberger; J. C. Dunlop; L. G. Efimov; M. Elnimr; J. Engelage; K. S. Engle; G. Eppley; L. Eun; O. Evdokimov; R. Fatemi; S. Fazio; J. Fedorisin; R. G. Fersch; P. Filip; E. Finch; Y. Fisyak; C. E. Flores; C. A. Gagliardi; D. R. Gangadharan; D. Garand; F. Geurts; A. Gibson; S. Gliske; O. G. Grebenyuk; D. Grosnick; Y. Guo; A. Gupta; S. Gupta; W. Guryn; B. Haag; O. Hajkova; A. Hamed; L-X. Han; R. Haque; J. W. Harris; J. P. Hays-Wehle; S. Heppelmann; A. Hirsch; G. W. Hoffmann; D. J. Hofman; S. Horvat; B. Huang; H. Z. Huang; P. Huck; T. J. Humanic; G. Igo; W. W. Jacobs; C. Jena; E. G. Judd; S. Kabana; K. Kang; K. Kauder; H. W. Ke; D. Keane; A. Kechechyan; A. Kesich; D. P. Kikola; J. Kiryluk; I. Kisel; A. Kisiel; D. D. Koetke; T. Kollegger; J. Konzer; I. Koralt; W. Korsch; L. Kotchenda; P. Kravtsov; K. Krueger; I. Kulakov; L. Kumar; R. A. Kycia; M. A. C. Lamont; J. M. Landgraf; K. D. Landry; S. LaPointe; J. Lauret; A. Lebedev; R. Lednicky; J. H. Lee; W. Leight; M. J. LeVine; C. Li; W. Li; X. Li; X. Li; Y. Li; Z. M. Li; L. M. Lima; M. A. Lisa; F. Liu; T. Ljubicic; W. J. Llope; R. S. Longacre; X. Luo; G. L. Ma; Y. G. Ma; D. M. M. D. Madagodagettige Don; D. P. Mahapatra; R. Majka; S. Margetis; C. Markert; H. Masui; H. S. Matis; D. McDonald; T. S. McShane; S. Mioduszewski; M. K. Mitrovski; Y. Mohammed; B. Mohanty; M. M. Mondal; M. G. Munhoz; M. K. Mustafa; M. Naglis; B. K. Nandi; Md. Nasim; T. K. Nayak; J. M. Nelson; L. V. Nogach; J. Novak; G. Odyniec; A. Ogawa; K. Oh; A. Ohlson; V. Okorokov; E. W. Oldag; R. A. N. Oliveira; D. Olson; M. Pachr; B. S. Page; S. K. Pal; Y. X. Pan; Y. Pandit; Y. Panebratsev; T. Pawlak; B. Pawlik; H. Pei; C. Perkins; W. Peryt; P. Pile; M. Planinic; J. Pluta; D. Plyku; N. Poljak; J. Porter; A. M. Poskanzer; C. B. Powell; C. Pruneau; N. K. Pruthi; M. Przybycien; P. R. Pujahari; J. Putschke; H. Qiu; S. Ramachandran; R. Raniwala; S. Raniwala; R. L. Ray; C. K. Riley; H. G. Ritter; J. B. Roberts; O. V. Rogachevskiy; J. L. Romero; J. F. Ross; A. Roy; L. Ruan; J. Rusnak; N. R. Sahoo; P. K. Sahu; I. Sakrejda; S. Salur; A. Sandacz; J. Sandweiss; E. Sangaline; A. Sarkar; J. Schambach; R. P. Scharenberg; A. M. Schmah; B. Schmidke; N. Schmitz; T. R. Schuster; J. Seger; P. Seyboth; N. Shah; E. Shahaliev; M. Shao; B. Sharma; M. Sharma; W. Q. Shen; S. S. Shi; Q. Y. Shou; E. P. Sichtermann; R. N. Singaraju; M. J. Skoby; D. Smirnov; N. Smirnov; D. Solanki; P. Sorensen; U. G. deSouza; H. M. Spinka; B. Srivastava; T. D. S. Stanislaus; J. R. Stevens; R. Stock; M. Strikhanov; B. Stringfellow; A. A. P. Suaide; M. C. Suarez; M. Sumbera; X. M. Sun; Y. Sun; Z. Sun; B. Surrow; D. N. Svirida; T. J. M. Symons; A. Szanto de Toledo; J. Takahashi; A. H. Tang; Z. Tang; L. H. Tarini; T. Tarnowsky; J. H. Thomas; A. R. Timmins; D. Tlusty; M. Tokarev; S. Trentalange; R. E. Tribble; P. Tribedy; B. A. Trzeciak; O. D. Tsai; J. Turnau; T. Ullrich; D. G. Underwood; G. Van Buren; G. van Nieuwenhuizen; J. A. Vanfossen, Jr.; R. Varma; G. M. S. Vasconcelos; R. Vertesi; F. Videbæk; Y. P. Viyogi; S. Vokal; S. A. Voloshin; A. Vossen; M. Wada; M. Walker; F. Wang; G. Wang; H. Wang; J. S. Wang; Q. Wang; X. L. Wang; Y. Wang; G. Webb; J. C. Webb; G. D. Westfall; H. Wieman; S. W. Wissink; R. Witt; Y. F. Wu; Z. Xiao; W. Xie; K. Xin; H. Xu; N. Xu; Q. H. Xu; W. Xu; Y. Xu; Z. Xu; Yan; C. Yang; Y. Yang; Y. Yang; P. Yepes; L. Yi; K. Yip; I-K. Yoo; Y. Zawisza; H. Zbroszczyk; W. Zha; J. B. Zhang; S. Zhang; X. P. Zhang; Y. Zhang; Z. P. Zhang; F. Zhao; J. Zhao; C. Zhong; X. Zhu; Y. H. Zhu; Y. Zoulkarneeva; M. Zyzak

    2013-08-09

    We present a study of the average transverse momentum ($p_t$) fluctuations and $p_t$ correlations for charged particles produced in Cu+Cu collisions at midrapidity for $\\sqrt{s_{NN}} =$ 62.4 and 200 GeV. These results are compared with those published for Au+Au collisions at the same energies, to explore the system size dependence. In addition to the collision energy and system size dependence, the $p_t$ correlation results have been studied as functions of the collision centralities, the ranges in $p_t$, the pseudorapidity $\\eta$, and the azimuthal angle $\\phi$. The square root of the measured $p_t$ correlations when scaled by mean $p_t$ is found to be independent of both colliding beam energy and system size studied. Transport-based model calculations are found to have a better quantitative agreement with the measurements compared to models which incorporate only jetlike correlations.

  17. Colliding Crystalline Beams

    E-Print Network [OSTI]

    Wei, J.

    2008-01-01

    6] J. Wei, et ai, Crystalline Beams and Related Issues,LABORATORY Colliding Crystalline Beams Jie Wei and A.M.CBP Note-262 Colliding Crystalline Beams* Jie Wei Brookhaven

  18. Simulations of beam-beam and beam-wire interactions in RHIC

    SciTech Connect (OSTI)

    Kim, Hyung J.; Sen, Tanaji; /Fermilab; Abreu, Natalia P.; Fischer, Wolfram; /Brookhaven

    2009-02-01

    The beam-beam interaction is one of the dominant sources of emittance growth and luminosity lifetime deterioration. A current carrying wire has been proposed to compensate long-range beam-beam effects in the LHC and strong localized long-range beam-beam effects are experimentally investigated in the RHIC collider. Tune shift, beam transfer function, and beam loss rate are measured in dedicated experiments. In this paper, they report on simulations to study the effect of beam-wire interactions based on diffusive apertures, beam loss rates, and beam transfer function using a parallelized weak-strong beam simulation code (BBSIMC). The simulation results are compared with measurements performed in RHIC during 2007 and 2008.

  19. Future of the Beam Energy Scan program at RHIC

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Odyniec, Grazyna; Bravina, L.; Foka, Y.; Kabana, S.

    2015-05-29

    The first exploratory phase of a very successful Beam Energy Scan Program at RHIC was completed in 2014 with Au+Au collisions at energies ranging from 7 to 39 GeV. Data sets taken earlier extended the upper limit of energy range to the ?sNN of 200 GeV. This provided an initial look into the uncharted territory of the QCD phase diagram, which is considered to be the single most important graph of our field. The main results from BES phase I, although effected by large statistical errors (steeply increasing with decreasing energy), suggest that the highest potential for discovery of themore »QCD Critical Point lies bellow ?sNN 20 GeV. Here, we discuss the plans and the preparation for phase II of the BES program, with an order of magnitude larger statistics, which is planned for 2018-2019. The BES II will focus on Au+Au collisions at ?sNN from 20 to 7 GeV in collider mode, and from ?sNN 7 to 3.5 GeV in the fixed target mode, which will be run concurrently with the collider mode operation.« less

  20. Central exclusive production at RHIC

    SciTech Connect (OSTI)

    Adamczyk, Leszek; Guryn, W?odek; Turnau, Jacek

    2014-11-10

    The present status and future plans of the physics program of Central Exclusive Production (CEP) at RHIC are described. The measurements are based on the detection of the forward protons from the Double Pomeron Exchange (DPE) process in the Roman Pot system and of the recoil system of charged particles from the DPE process measured in the STAR experiment’s Time Projection Chamber (TPC). The data described here were taken using polarized proton-proton collisions at ps = 200 GeV. The preliminary spectra of two pion and four pion invariant mass reconstructed by STAR TPC in central region of pseudo-rapidity |#17;| < 1, are presented. Near future plans to take data with the current system at center-of-mass energy ps = 200 GeV and plans to upgrade the forward proton tagging sys- tem are presented. Also a possible addition of the Roman Pots to the sPHENIX detector is discussed.

  1. Central exclusive production at RHIC

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Adamczyk, Leszek; Guryn, W?odek; Turnau, Jacek

    2014-11-10

    The present status and future plans of the physics program of Central Exclusive Production (CEP) at RHIC are described. The measurements are based on the detection of the forward protons from the Double Pomeron Exchange (DPE) process in the Roman Pot system and of the recoil system of charged particles from the DPE process measured in the STAR experiment’s Time Projection Chamber (TPC). The data described here were taken using polarized proton-proton collisions at ps = 200 GeV. The preliminary spectra of two pion and four pion invariant mass reconstructed by STAR TPC in central region of pseudo-rapidity |#17;| more »1, are presented. Near future plans to take data with the current system at center-of-mass energy ps = 200 GeV and plans to upgrade the forward proton tagging sys- tem are presented. Also a possible addition of the Roman Pots to the sPHENIX detector is discussed.« less

  2. Central Exclusive Production at RHIC

    SciTech Connect (OSTI)

    Adamczyk, Leszek [Faculty of Physics and Applied Computer Science , AGH - University of Science and Technology, Krakow, (Poland); Guryn, Wlodek [Brookhaven National Laboratory (BNL), Upton, NY (United States); Turnau, Jacek [Institute of Nuclear Physics, Krakow, (Poland)

    2014-11-10

    The present status and future plans of the physics program of Central Exclusive Production (CEP) at RHIC are described. The measurements are based on the detection of the forward protons from the Double Pomeron Exchange (DPE) process in the Roman Pot system and of the recoil system of charged particles from the DPE process measured in the STAR experiment’s Time Projection Chamber (TPC). The data described here were taken using polarized proton-proton collisions at ps = 200 GeV. The preliminary spectra of two pion and four pion invariant mass reconstructed by STAR TPC in central region of pseudo-rapidity |#17;| < 1, are presented. Near future plans to take data with the current system at center-of-mass energy ps = 200 GeV and plans to upgrade the forward proton tagging sys- tem are presented. Also a possible addition of the Roman Pots to the sPHENIX detector is discussed.

  3. Fermilab Today

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Ion Collider (RHIC), as it's called, recently came out of hibernation equipped with new gear for spilling the secrets of atoms. RHIC pales next to Europe's Large Hadron Collider...

  4. Simulation of Electron Cloud Density Distributions in RHIC Dipoles at Injection and Transition and Estimates for Scrubbing Times

    SciTech Connect (OSTI)

    He,P.; Blaskiewicz, M.; Fischer, W.

    2009-01-02

    In this report we summarize electron-cloud simulations for the RHIC dipole regions at injection and transition to estimate if scrubbing over practical time scales at injection would reduce the electron cloud density at transition to significantly lower values. The lower electron cloud density at transition will allow for an increase in the ion intensity.

  5. Transport properties of the fluid produced at RHIC

    E-Print Network [OSTI]

    Rajeev S. Bhalerao

    2010-03-17

    It is by now well known that the relativistic heavy-ion collisions at RHIC, BNL have produced a strongly interacting fluid with remarkable properties, among them the lowest ever observed ratio of the coefficient of shear viscosity to entropy density. Arguments based on ideas from the String Theory, in particular the AdS/CFT correspondence, led to the conjecture --- now known to be violated --- that there is an absolute lower limit $1/4 \\pi$ on the value of this ratio. Causal viscous hydrodynamics calculations together with the RHIC data have put an upper limit on this ratio, a small multiple of $1/4 \\pi$, in the relevant temperature regime. Less well-determined is the ratio of the coefficient of bulk viscosity to entropy density. These transport coefficients have also been studied nonperturbatively in the lattice QCD framework, and perturbatively in the limit of high-temperature QCD. Another interesting transport coefficient is the coefficient of diffusion which is also being studied in this context. I review some of these recent developments and then discuss the opportunities presented by the anticipated LHC data, for the general nuclear physics audience.

  6. Chemical properties of super-hadronic matter created in relativistic heavy ion collisions

    E-Print Network [OSTI]

    Scott Pratt; Claudia Ratti; William Patrick McCormack

    2014-09-07

    Preliminary charge balance functions from the STAR Collaboration at the Relativistic Heavy Ion Collider (RHIC) are compared to a model where quarks are produced in two waves. If a chemically equilibrated quark-gluon plasma (QGP) is created the strength and diffusive spread of the first wave should be governed by the chemical composition of the QGP, while the second wave should be determined by the increased number of quarks required to make the observed final-state hadrons. A simple model parameterizes the chemistry of the super-hadronic matter and the two correlation lengths for the two waves. Calculations are compared to preliminary data from the STAR Collaboration. The chemistry of the super-hadronic matter appears to be within 20\\% of expectations from lattice gauge theory.

  7. Constraints on models for the initial collision geometry in ultra relativistic heavy ion collisions

    E-Print Network [OSTI]

    Roy A. Lacey; Rui Wei; N. N. Ajitanand; J. M. Alexander; X. Gong; J. Jia; A. Taranenko; R. Pak; Horst Stocker

    2010-05-21

    Monte Carlo (MC) simulations are used to compute the centrality dependence of the collision zone eccentricities ($\\epsilon_{2,4}$), for both spherical and deformed ground state nuclei, for different model scenarios. Sizable model dependent differences are observed. They indicate that measurements of the $2^{\\text{nd}}$ and $4^{\\text{th}}$ order Fourier flow coefficients $v_{2,4}$, expressed as the ratio $\\frac{v_4}{(v_2)^2}$, can provide robust constraints for distinguishing between different theoretical models for the initial-state eccentricity. Such constraints could remove one of the largest impediments to a more precise determination of the specific viscosity from precision $v_{2,4}$ measurements at the Relativistic Heavy Ion Collider (RHIC).

  8. Photon-Photon Colliders

    E-Print Network [OSTI]

    Sessler, Andrew M.

    2008-01-01

    diverse pairs of particles are produced. In photon-photon colliders. the intensity of the light is so strongunpolarized electrons or photons and fully polarized photons

  9. Challenging the utility of third-order azimuth harmonics in the description of ultra-relativistic heavy-ion collisions

    E-Print Network [OSTI]

    R. L. Ray; D. J. Prindle; T. A. Trainor

    2013-08-20

    In recent years it has become conventional practice to include higher-order cylindrical harmonics in the phenomenological description of two-particle angular correlations from ultra-relativistic heavy-ion collisions. These model elements, whose dependence on relative azimuth angle has the form $\\cos[m(\\phi_1-\\phi_2)]$ where $m > 2$, were introduced to support a hydrodynamic flow interpretation of the same-side ($|\\phi_1-\\phi_2| 2$ harmonics are not required by the data, that they destabilize the fitting models, and that their net effect is to decompose the same-side peak into two components, one being dependent on and the other being independent of relative pseudorapidity. Thus we are lead to question whether descriptions of angular correlation data including higher-order harmonics inform our understanding of the same-side peak or heavy-ion collisions in general. Results from analysis of two-dimensional angular correlation data from the Relativistic Heavy-Ion Collider (RHIC) and the Large Hadron Collider (LHC) show that the RHIC data do not exclude a single-Gaussian hypothesis for the same-side peak. We find that the net effect of including the $m = 3$ harmonic or azimuth sextupole in the fitting model is the inclusion of small non-Gaussian dependence in the mathematical description of the same-side peak. Those non-Gaussian effects are systematically insignificant and can be accommodated by minor perturbations to the same-side 2D Gaussian peak model, which act locally at small relative azimuth. We also demonstrate that the 0-1% 2D angular correlation data for 2.76 TeV Pb+Pb collisions from ATLAS, which display an away-side double peak on azimuth, do not require a sextupole and exclude a positive same-side sextupole.

  10. Muon Muon Collider: Feasibility Study

    SciTech Connect (OSTI)

    Gallardo, J.C.; Palmer, R.B.; Tollestrup, A.V.; Sessler, A.M.; Skrinsky, A.N.; Ankenbrandt, C.; Geer, S.; Griffin, J.; Johnstone, C.; Lebrun, P.; McInturff, A.; Mills, Frederick E.; Mokhov, N.; Moretti, A.; Neuffer, D.; Ng, K.Y.; Noble, R.; Novitski, I.; Popovic, M.; Qian, C.; Van Ginneken, A. ,

    2012-04-05

    A feasibility study is presented of a 2 + 2 TeV muon collider with a luminosity of L = 10{sup 35} cm{sup -2}s{sup -1}. The resulting design is not optimized for performance, and certainly not for cost; however, it does suffice - we believe - to allow us to make a credible case, that a muon collider is a serious possibility for particle physics and, therefore, worthy of R and D support so that the reality of, and interest in, a muon collider can be better assayed. The goal of this support would be to completely assess the physics potential and to evaluate the cost and development of the necessary technology. The muon collider complex consists of components which first produce copious pions, then capture the pions and the resulting muons from their decay; this is followed by an ionization cooling channel to reduce the longitudinal and transverse emittance of the muon beam. The next stage is to accelerate the muons and, finally, inject them into a collider ring wich has a small beta function at the colliding point. This is the first attempt at a point design and it will require further study and optimization. Experimental work will be needed to verify the validity of diverse crucial elements in the design. Muons because of their large mass compared to an electron, do not produce significant synchrotron radiation. As a result there is negligible beamstrahlung and high energy collisions are not limited by this phenomena. In addition, muons can be accelerated in circular devices which will be considerably smaller than two full-energy linacs as required in an e{sup +} - e{sup -} collider. A hadron collider would require a CM energy 5 to 10 times higher than 4 TeV to have an equivalent energy reach. Since the accelerator size is limited by the strength of bending magnets, the hadron collider for the same physics reach would have to be much larger than the muon collider. In addition, muon collisions should be cleaner than hadron collisions. There are many detailed particle reactions which are open to a muon collider and the physics of such reactions - what one learns and the necessary luminosity to see interesting events - are described in detail. Most of the physics accesible to an e{sup +} - e{sup -} collider could be studied in a muon collider. In addition the production of Higgs bosons in the s-channel will allow the measurement of Higgs masses and total widths to high precision; likewise, t{bar t} and W{sup +}W{sup -} threshold studies would yield m{sub t} and m{sub w} to great accuracy. These reactions are at low center of mass energy (if the MSSM is correct) and the luminosity and {Delta}p/p of the beams required for these measurements is detailed in the Physics Chapter. On the other hand, at 2 + 2 TeV, a luminosity of L {approx} 10{sup 35} cm{sup -2}s{sup -1} is desirable for studies such as, the scattering of longitudinal W bosons or the production of heavy scalar particles. Not explored in this work, but worth noting, are the opportunities for muon-proton and muon-heavy ion collisions as well as the enormous richness of such a facility for fixed target physics provided by the intense beams of neutrinos, muons, pions, kaons, antiprotons and spallation neutrons. To see all the interesting physics described herein requires a careful study of the operation of a detector in the very large background. Three sources of background have been identified. The first is from any halo accompanying the muon beams in the collider ring. Very carefully prepared beams will have to be injected and maintained. The second is due to the fact that on average 35% of the muon energy appears in its decay electron. The energy of the electron subsequently is converted into EM showers either from the synchrotron radiation they emit in the collider magnetic field or from direct collision with the surrounding material. The decays that occur as the beams traverse the low beta insert are of particular concern for detector backgrounds. A third source of background is e{sup +} - e{sup -} pair creation from {mu}{sup +} - {mu}{sup -} interaction. Studies of

  11. Review of Forward Physics at RHIC

    E-Print Network [OSTI]

    R. Debbe

    2006-09-20

    The RHIC high energy collision of species ranging from p+p, p(d)+A to A+A provide access to the {small-x} component of the hadron wave function. The RHIC program has brought renewed interest in that subject with its ability to reach values of the parton momentum fraction smaller than 0.01 with studies of particle production at high rapidity. Furthermore, the use of heavy nuclei in the p(d)+A collisions facilitates the study of saturation effects in the gluonic component of the nuclei because the appropriate scale for that regime grows as A^1/3. We review the experimental results of the RHIC program that have relevance to {small-x} emphasizing the physics extracted from d+Au collisions and their comparison to p+p collisions at the same energy.

  12. RHIC BPM SYSTEM MODIFICATIONS AND PERFORMANCE.

    SciTech Connect (OSTI)

    SATOGATA, T.; CALAGA, R.; CAMERON, P.; ET AL.

    2005-05-16

    The RHIC beam position monitor (BPM) system provides independent average orbit and turn-by-turn (TBT) position measurements. In each ring, there are 162 measurement locations per plane (horizontal and vertical) for a total of 648 BPM planes in the RHIC machine. During 2003 and 2004 shutdowns, BPM processing electronics were moved from the RHIC tunnel to controls alcoves to reduce radiation impact, and the analog signal paths of several dozen modules were modified to eliminate gain-switching relays and improve signal stability. This paper presents results of improved system performance, including stability for interaction region beam-based alignment efforts. We also summarize performance of recently-added DSP profile scan capability, and improved million-turn TBT acquisition channels for 10 Hz triplet vibration, nonlinear dynamics, and echo studies.

  13. SYSTEMATIC STUDIES OF HEAVY ION COLLISIONS TO SEARCH FOR QUARK-GLUON PLASMA

    SciTech Connect (OSTI)

    Fuqiang Wang

    2007-11-29

    This is the final technical report for DOE Outstanding Junior Investigator (OJI) Award, 'Systematic Studies of Heavy Ion Collisions to Search for Quark-Gluon Plasma', grant DE-FG02-02ER41219, Principal Investigator (PI) Fuqiang Wang. The research under the grant was divided into two phases. The first concentrated on systematic studies of soft hadron production at low transverse momentum (p{sub T}), in particular the production of (anti-)baryon and strangeness in heavy ion collisions at RHIC energies. The second concentrated on measurements of di-hadron and multi-hadron jet-correlations and investigations of medium response to jets. The research was conducted at the Relativistic Heavy-Ion Collider (RHIC) at BNL with the Solenoidal Tracker At RHIC (STAR) experiment. The total grant is $214,000. The grant established a PC farm solely used for this research. The PC farm consists of 8 nodes with a total of 16 CPUs and 3 disk servers of total 2 TB shared storage. The current balance of the grant is $19,985. The positive balance is because an initial purchase of $22,600 for the PC farm came out of the PI's start-up fund due to the lateness of the award. The PC farm is an integral part of the Purdue Physics Department's computer cluster. The grant supported two Ph.D. graduate students. Levente Molnar was supported from July 2002 to December 2003, and worked on soft hadron production. His thesis title is Systematics of Identified Particle Production in pp, d-Au and Au-Au Collisions at RHIC Energies. He graduated in 2006 and now is a Postdoctoral fellow at INFN Sezione di Bari, Italy working on the ALICE experiment at the LHC. Jason Ulery was supported from January 2004 to July 2007. His thesis title is Two- and Three-Particle Jet-Like Correlations. He defended his thesis in October 2007 and is moving to Frankfurt University, Germany to work on the ALICE experiment at the LHC. The research by this grant resulted in 7 journal publications (2 PRL, 1 PLB, 1 PRC, 2 submitted and 1 in preparation), and 14 invited talks and 10 contributed talks at major conferences. These are listed at end of this report.

  14. The Potential of the Linac-Ring Type Colliders for Particle and Nuclear Physics

    E-Print Network [OSTI]

    A. K. Ciftci; E. Recepoglu; S. Sultansoy; O. Yavas; M. Yilmaz

    2003-10-02

    Linac-ring type colliders will open new windows for both energy frontier and particle factories. Concerning the first direction, these machines seem to be a sole way to TeV scale in lepton-hadron collisison at constituent level. An essential advantage of the linac-ring type lepton-hadron colliders is the possibility of the construction of gamma-p, gamma-A and FELgamma-A colliders based on them. Today, eRHIC, THERA (TESLA on HERA)and Linac*LHC can be considered as realistic candidates for future lepton-hadron and photon hadron colliders. When it comes to factories, one can reach essentially higher luminosities comparing to standard ring-ring type machines. For example, L=10^34 cm^-2 s^-1 can be achieved for phi and charm-tau factories. In this presentation we briefly discuss the parameters and physics search potential of the linac-ring type machines.

  15. RHIC Enhanced Luminosity Program Wolfram Fischer

    E-Print Network [OSTI]

    experiments ~ 5% maintenance and access goal 100h/week #12;Wolfram Fischer 9 Enhanced Design Parameters #12;Wolfram Fischer 10 Enhanced Design Parameters (~2008*) Parameter unit Achieved Enhanced design Au1 RHIC Enhanced Luminosity Program Wolfram Fischer Science and Technology Review by the Office

  16. The International Linear Collider

    E-Print Network [OSTI]

    Jim Brau; Paul Grannis; Mike Harrison; Michael Peskin; Marc Ross; Harry Weerts

    2013-04-09

    We present a brief summary of the International Linear Collider as documented in the 2013 Technical Design Report. The Technical Design Report has detailed descriptions of the accelerator baseline design for a 500 GeV e+e- linear collider, the R&D program that has demonstrated its feasibility, the physics goals and expected sensitivities, and the description of the ILD and SiD detectors and their capabilities.

  17. 405th Brookhaven Lecture

    ScienceCinema (OSTI)

    Vadim Ptitsyn

    2010-09-01

    "E-RHIC - Future Electron-Ion Collider at BNL. While RHIC scientists continue their quest to look deep into nuclear phenomena resulting from collisions of ion beams and beams of polarized protons, new design work is under way for a possible extension of RHIC to include e-RHIC, a 10-billion electron volt, high-intensity polarized proton beam.

  18. PROCEEDINGS OF RIKEN BNL RESEARCH CENTER WORKSHOP, VOLUME 57, HIGH PT PHYSICS AT RHIC, DECEMBER 2-6, 2003

    SciTech Connect (OSTI)

    Kretzer, Stefan; Venugopalan, Raju; Vogelsang, Werner

    2004-02-18

    The AuAu, dAu, and pp collision modes of the RHIC collider at BNL have led to the publication of exciting high p{perpendicular} particle production data. There have also been two physics runs with polarized protons, and preliminary results on the double-spin asymmetry for pion production had been presented very recently. The ontological questions behind these measurements are fascinating: Did RHIC collisions create a Quark-Gluon-Plasma phase and did they verify the Color Glass Condensate as the high energy limit of QCD? Will the Spin Crisis finally be resolved in terms of gluon polarization and what new surprises are we yet to meet for Transverse Spin? Phenomena related to sub-microscopic questions as important as these call for interpretations that are footed in solid theory. At large p{perpendicular}, perturbative concepts are legitimately expected to provide useful approaches. The corresponding hard parton dynamics are, in several ways, key to unraveling the initial or final state and collisional phase of hard scattering events in vacuum as well as in hot or cold nuclear matter. Before the advent of RHIC data, a RIKEN-BNL workshop had been held at BNL in March 1999 on ''Hard Parton Physics in High Energy Nuclear Collisions''. The 2003 workshop on ''High p{perpendicular} Physics at RHIC'' was a logical continuation of this previous workshop. It gave the opportunity to revisit the 1999 expectations in the light of what has been found in the meantime and, at the same time, to critically discuss the underlying theoretical concepts. We brought together theorists who have done seminal work on the foundations of parton phenomenology in field theory, with theorists and experimentalists who are presently working on RHIC phenomenology. The participants were both from a high-energy physics and nuclear physics background and it remains only to be said here that this chemistry worked perfectly and the workshop was a great success.

  19. Relativistic Heavy Ion Collider Funding Agencies

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Promotion of Science National Council for Scientific and Technological Development, Brazil Research Supporting Foundation of the State of Sao Paulo, Brazil National Natural...

  20. Quarkonium formation time in relativistic heavy-ion collisions

    E-Print Network [OSTI]

    Taesoo Song; Che Ming Ko; Su Houng Lee

    2015-02-19

    We calculate the quarkonium formation time in relativistic heavy-ion collisions from the space-time correlator of heavy quark vector currents in a hydrodynamics background with the initial nonequilibrium stage expanding only in the longitudinal direction. Using in-medium quarkonia properties determined with the heavy quark potential taken to be the free energy from lattice calculations and the fact that quarkonia can only be formed below their dissociation temperatures due to color screening, we find that $\\Upsilon$(1S), $\\Upsilon$(2S), $\\Upsilon$(3S), $J/\\psi$ and $\\psi^\\prime$ are formed, respectively, at 1.2, 6.6, 8.8, 5.8, and 11.0 fm/c after the quark pair are produced in central Au+Au collisions at the top energy of Relativistic Heavy Ion Collider (RHIC), and these times become shorter in semi-central collisions. We further show, as an example, that including the effect of formation time enhances appreciably the survivability of $\\Upsilon$(1S) in the produced hot dense matter.

  1. Beam physics in future electron hadron colliders

    E-Print Network [OSTI]

    Valloni, A; Klein, M; Schulte, D; Zimmermann, F

    2013-01-01

    High-energy electron-hadron collisions could support a rich research programme in particle and nuclear physics. Several future projects are being proposed around the world, in particular eRHIC at BNL, MEIC at TJNAF in the US, and LHeC at CERN in Europe. This paper will highlight some of the accelerator physics issues, and describe related technical developments and challenges for these machines. In particular, optics design and beam dynamics studies are discussed, including longitudinal phase space manipulation, coherent synchrotron radiation, beam-beam kink instability, ion effects, as well as mitigation measures for beam break up and for space-charge induced emittance growth, all of which could limit the machine performance. Finally, first steps are presented towards an LHeC R&D facility, which should investigate relevant beam-physics processes.

  2. The International Linear Collider

    E-Print Network [OSTI]

    Barish, Barry

    2013-01-01

    In this article, we describe the key features of the recently completed technical design for the International Linear Collider (ILC), a 200-500 GeV linear electron-positron collider (expandable to 1 TeV) that is based on 1.3 GHz superconducting radio-frequency (SCRF) technology. The machine parameters and detector characteristics have been chosen to complement the Large Hadron Collider physics, including the discovery of the Higgs boson, and to further exploit this new particle physics energy frontier with a precision instrument. The linear collider design is the result of nearly twenty years of R&D, resulting in a mature conceptual design for the ILC project that reflects an international consensus. We summarize the physics goals and capability of the ILC, the enabling R&D and resulting accelerator design, as well as the concepts for two complementary detectors. The ILC is technically ready to be proposed and built as a next generation lepton collider, perhaps to be built in stages beginning as a Hig...

  3. Photon collider at TESLA

    E-Print Network [OSTI]

    Valery Telnov

    2001-03-06

    High energy photon colliders (gamma-gamma, gamma-electron) based on backward Compton scattering of laser light is a very natural addition to e+e- linear colliders. In this report we consider this option for the TESLA project. Recent study has shown that the horizontal emittance in the TESLA damping ring can be further decreased by a factor of four. In this case the gamma-gamma luminosity luminosity in the high energy part of spectrum can reach (1/3)L_{e+e-}. Typical cross sections of interesting processes in gamma-gamma collisions are higher than those in e+e- collisions by about one order of magnitude, so the number of events in gamma-gamma collisions will be more than that in e+e- collisions. Photon colliders can, certainly, give additional information and they are the best for the study of many phenomena. The main question is now the technical feasibility. The key new element in photon colliders is a very powerful laser system. An external optical cavity is a promising approach for the TESLA project. A free electron laser is another option. However, a more straightforward solution is ``an optical storage ring (optical trap)'' with diode pumped solid state laser injector which is today technically feasible. This paper briefly reviews the status of a photon collider based at TESLA, its possible parameters and existing problems.

  4. RHIC Au beam in Run 2014

    SciTech Connect (OSTI)

    Zhang, S. Y.

    2014-09-15

    Au beam at the RHIC ramp in run 2014 is reviewed together with the run 2011 and run 2012. Observed bunch length and longitudinal emittance are compared with the IBS simulations. The IBS growth rate of the longitudinal emittance in run 2014 is similar to run 2011, and both are larger than run 2012. This is explained by the large transverse emittance at high intensity observed in run 2012, but not in run 2014. The big improvement of the AGS ramping in run 2014 might be related to this change. The importance of the injector intensity improvement in run 2014 is emphasized, which gives rise to the initial luminosity improvement of 50% in run 2014, compared with the previous Au-Au run 2011. In addition, a modified IBS model, which is calibrated using the RHIC Au runs from 9.8 GeV/n to 100 GeV/n, is presented and used in the study.

  5. Azimuthal Jet Tomography at RHIC and LHC

    E-Print Network [OSTI]

    Barbara Betz; Miklos Gyulassy

    2014-02-14

    A generic jet-energy loss model that is coupled to state-of-the-art hydrodynamic fields and interpolates between a wide class of running coupling pQCD-based and AdS/CFT-inspired models is compared to recent data on the azimuthal and transverse momentum dependence of high-pT pion nuclear modification factors and high-pT elliptic flow measured at RHIC and LHC. We find that RHIC data are surprisingly consistent with various scenarios considered. However, extrapolations to LHC energies favor running coupling pQCD-based models of jet-energy loss. While conformal holographic models are shown to be inconsistent with data, recent non-conformal generalizations of AdS holography may provide an alternative description.

  6. Ferrite HOM Absorber for the RHIC ERL

    SciTech Connect (OSTI)

    Hahn,H.; Choi, E.M.; Hammons, L.

    2008-10-01

    A superconducting Energy Recovery Linac is under construction at Brookhaven National Laboratory to serve as test bed for RHIC upgrades. The damping of higher-order modes in the superconducting five-cell cavity for the Energy-Recovery linac at RHIC is performed exclusively by two ferrite absorbers. The ferrite properties have been measured in ferrite-loaded pill box cavities resulting in the permeability values given by a first-order Debye model for the tiled absorber structure and an equivalent permeability value for computer simulations with solid ring dampers. Measured and simulated results for the higher-order modes in the prototype copper cavity are discussed. First room-temperature measurements of the finished niobium cavity are presented which confirm the effective damping of higher-order modes in the ERL. by the ferrite absorbers.

  7. The "Hot" Science of RHIC Status and Future

    E-Print Network [OSTI]

    The "Hot" Science of RHIC Status and Future Berndt Mueller Brookhaven National Laboratory Associate #12;RHIC NSRL LINAC Booster AGS Tandems STAR 6:00 o'clock PHENIX 8:00 o'clock (PHOBOS) 10:00 o Friday, April 5, 13 #12;RHIC NSRL LINAC Booster AGS Tandems STAR 6:00 o'clock PHENIX 8:00 o'clock (PHOBOS

  8. Analysis of RHIC beam dump pre-fires

    SciTech Connect (OSTI)

    Zhang, W.; Ahrens, L.; Fischer, W.; Hahn, H.; Mi, J.; Sandberg, J.; Tan, Y.

    2011-03-28

    It has been speculated that the beam may cause instability of the RHIC Beam Abort Kickers. In this study, we explore the available data of past beam operations, the device history of key modulator components, and the radiation patterns to examine the correlations. The RHIC beam abort kicker system was designed and built in the 90's. Over last decade, we have made many improvements to bring the RHIC beam abort kicker system to a stable operational state. However, the challenge continues. We present the analysis of the pre-fire, an unrequested discharge of kicker, issues which relates to the RHIC machine safety and operational stability.

  9. Proceedings of RIKEN BNL Research Center Workshop: Brookhaven Summer Program on Quarkonium Production in Elementary and Heavy Ion Collisions

    SciTech Connect (OSTI)

    Dumitru, A.; Lourenco, C.; Petreczky, P.; Qiu, J., Ruan, L.

    2011-08-03

    Understanding the structure of the hadron is of fundamental importance in subatomic physics. Production of heavy quarkonia is arguably one of the most fascinating subjects in strong interaction physics. It offers unique perspectives into the formation of QCD bound states. Heavy quarkonia are among the most studied particles both theoretically and experimentally. They have been, and continue to be, the focus of measurements in all high energy colliders around the world. Because of their distinct multiple mass scales, heavy quarkonia were suggested as a probe of the hot quark-gluon matter produced in heavy-ion collisions; and their production has been one of the main subjects of the experimental heavy-ion programs at the SPS and RHIC. However, since the discovery of J/psi at Brookhaven National Laboratory and SLAC National Accelerator Laboratory over 36 years ago, theorists still have not been able to fully understand the production mechanism of heavy quarkonia, although major progresses have been made in recent years. With this in mind, a two-week program on quarkonium production was organized at BNL on June 6-17, 2011. Many new experimental data from LHC and from RHIC were presented during the program, including results from the LHC heavy ion run. To analyze and correctly interpret these measurements, and in order to quantify properties of the hot matter produced in heavy-ion collisions, it is necessary to improve our theoretical understanding of quarkonium production. Therefore, a wide range of theoretical aspects on the production mechanism in the vacuum as well as in cold nuclear and hot quark-gluon medium were discussed during the program from the controlled calculations in QCD and its effective theories such as NRQCD to various models, and to the first principle lattice calculation. The scientific program was divided into three major scientific parts: basic production mechanism for heavy quarkonium in vacuum or in high energy elementary collisions; the formation of quarkonium in nuclear medium as well as the strong interacting quark-gluon matter produced in heavy ion collisions; and heavy quarkonium properties from the first principle lattice calculations. The heavy quarkonium production at a future Electron-Ion Collider (EIC) was also discussed at the meeting. The highlight of the meeting was the apparent success of the NRQCD approach at next-to-leading order in the description of the quarkonium production in proton-proton, electron-proton and electron positron collisions. Still many questions remain open in lattice calculations of in-medium quarkonium properties and in the area of cold nuclear matter effects.

  10. The Muon Collider

    SciTech Connect (OSTI)

    Zisman, Michael S

    2010-05-17

    We describe the scientific motivation for a new type of accelerator, the muon collider. This accelerator would permit an energy-frontier scientific program and yet would fit on the site of an existing laboratory. Such a device is quite challenging, and requires a substantial R&D program. After describing the ingredients of the facility, the ongoing R&D activities of the Muon Accelerator Program are discussed. A possible U.S. scenario that could lead to a muon collider at Fermilab is briefly mentioned.

  11. The Muon Collider

    SciTech Connect (OSTI)

    Zisman, Michael S.

    2011-01-05

    We describe the scientific motivation for a new type of accelerator, the muon collider. This accelerator would permit an energy-frontier scientific program and yet would fit on the site of an existing laboratory. Such a device is quite challenging, and requires a substantial R&D program. After describing the ingredients of the facility, the ongoing R&D activities of the Muon Accelerator Program are discussed. A possible U.S. scenario that could lead to a muon collider at Fermilab is briefly mentioned.

  12. The International Linear Collider

    E-Print Network [OSTI]

    Marco Battaglia

    2007-05-28

    The International Linear Collider (ILC) is the next large scale project in accelerator particle physics. Colliding electrons with positrons at energies from 0.3 TeV up to about 1 TeV, the ILC is expected to provide the accuracy needed to complement the LHC data and extend the sensitivity to new phenomena at the high energy frontier and answer some of the fundamental questions in particle physics and in its relation to Cosmology. This paper reviews some highlights of the ILC physics program and some of the major challenges for the accelerator and detector design.

  13. International linear collider reference design report

    E-Print Network [OSTI]

    Aarons, G.

    2008-01-01

    A. Loew, et al. , “International Linear Collider Technologyfor the International Linear Collider”, in preparation [37]for the International Linear Collider,” in PAC05,http://

  14. Jets in 200 GeV p+p and d+Au collisions from the STAR experiment at RHIC

    E-Print Network [OSTI]

    Jan Kapitan; for the STAR Collaboration

    2010-11-24

    Full jet reconstruction in heavy-ion collisions is a promising tool for the quantitative study of properties of the dense medium produced at RHIC. Measurements of d+Au collisions are important to disentangle initial state nuclear effects from medium-induced kT broadening and jet quenching. Study of jet production and properties in d+Au in combination with similar studies in p+p is an important baseline measurement needed to better understand heavy-ion results. We present mid-rapidity inclusive jet pT spectra and di-jet correlations (kT) in 200 GeV p+p and d+Au collisions from the 2007-2008 RHIC run. We discuss the methods used to correct the data for detector effects and for background in d+Au collisions.

  15. Thermal Radiation from Heavy Ion Collisions at RHIC

    E-Print Network [OSTI]

    Jan-e Alam

    2007-03-19

    The direct photon spectrum measured by the PHENIX collaboration in Au + Au collisions at sqrt{s_{NN}}=200 GeV has been analyzed. It has been shown that the data can be reproduced reasonably well by assuming a deconfined state of thermalized quarks and gluons. The effects of the equation of state on the value of the initial temperature have been studied. The modifications of hadronic properties at non-zero temperature have been taken in to account.

  16. High density matter in AGS, SPS and RHIC collisions: Proceedings. Volume 9

    SciTech Connect (OSTI)

    NONE

    1998-12-01

    This 1-day workshop focused on phenomenological models regarding the specific question of the maximum energy density achievable in collisions at AGS, SPS and RHIC. The idea was to have 30-minute (or less) presentations of each model--but not the model as a whole, rather then that strongly narrowed to the above physics question. The key topics addressed were: (1) to estimate the energy density in heavy-ion collisions within a model, and to discuss its physical implications; (2) to suggest experimental observables that may confirm the correctness of a model approach--with respect to the energy density estimate; (3) to compare with existing data from AGS and SPS heavy-ion collisions, and to give predictions for the future RHIC experiments. G. Ogilvie started up the workshop with a critical summary of experimental manifestations of high-density matter at the AGS, and gave a personal outlook on RHIC physics. R. Mattiello talked about his newly developed hadron cascade model for applications to AGS and SPS collisions. Next, D. Kharzeev gave a nice introduction of the Glauber approach to high-energy collisions and illustrated the predictive power of this approach in nucleus-nucleus collisions at the SPS. It followed S. Vance with a presentation of the baryon-junction model to explain the observed baryon stopping phenomenon in collisions of heavy nuclei. S. Bass continued with a broad perspective of the UrQMD model, and provided insight into the details of the microscopic dynamical features of nuclear collisions at high energy. J. Sandweiss and J. Kapusta addressed the interesting aspect of photon production in peripherical nuclear collisions due to intense electromagnetic bremstrahlung by the highly charged, fast moving ions. Finally, H. Sorge closed up the one-day workshop with a presentation of his recent work with the RQMD model. This report consists of a summary and vugraphs of the presentations.

  17. Stochastic Cooling in Muon Colliders

    E-Print Network [OSTI]

    Barletta, W.A.

    2008-01-01

    Research Division Stochastic Cooling in Muon Colliders W.A.AC03-76SFOOO98. STOCHASTIC COOLING IN MUON COLLIDERS Williamcan consider the stochastic cooling option as more than a

  18. Elliptic Flow and Shear Viscosity within a Transport Approach from RHIC to LHC Energy

    E-Print Network [OSTI]

    S. Plumari; V. Greco

    2011-10-11

    We have investigated the build up of anisotropic flows within a parton cascade approach at fixed shear viscosity to entropy density \\eta/s to study the generation of collective flows in ultra-relativistic heavy ion collisions. We present a study of the impact of a temperature dependent \\eta/s(T) on the generation of the elliptic flow at both RHIC and LHC. Finally we show that the transport approach, thanks to its wide validity range, is able to describe naturally the rise - fall and saturation of the v_2(p_T) observed at LHC.

  19. Two-Photon Physics in Nucleus-Nucleus Collisions at RHIC

    E-Print Network [OSTI]

    Joakim Nystrand; Spencer Klein; the STAR Collaboration

    1998-11-18

    Ultra-relativistic heavy-ions carry strong electromagnetic and nuclear fields. Interactions between these fields in peripheral nucleus-nucleus collisions can probe many interesting physics topics. This presentation will focus on coherent two-photon and photonuclear processes at RHIC. The rates for these interactions will be high. The coherent coupling of all the protons in the nucleus enhances the equivalent photon flux by a factor Z^2 up to an energy of ~3 GeV. The plans for studying coherent interactions with the STAR experiment will be discussed. Experimental techniques for separating signal from background will be presented.

  20. PROCEEDINGS OF RIKEN BNL RESEARCH CENTER WORKSHOP ON SPIN PHYSICS AT RHIC IN YEAR-1 AND BEYOND.

    SciTech Connect (OSTI)

    BLAND, L.; BOER, D.; SAITO, N.; VOGELSANG, W.

    2001-05-14

    The much anticipated RHIC spin physics program will commence this fall when the first physics run with colliding beams of polarized protons is expected. More specifically, the planned year-1 RHIC-Spin measurements are (1) the double-spin asymmetry A{sub LL}{sup {pi}} in production of pions by collisions of longitudinally polarized protons (in order to obtain first information on the proton's spin-dependent gluon density, {Delta}g); (2) the transverse single-spin asymmetry A{sub N}{sup {pi}} for pion production. These two reactions provided part of the motivation for our workshop. On the first day there were informative talks on the specific plans of STAR (by Rakness) and PHENIX (by Goto) for the polarized run of Year-1. Some of the theoretical questions related to the double-spin asymmetry A{sub LL}{sup {pi}} were discussed on the first day by Vogelsang and Kretzer, which centered mostly around the questions of how well the unpolarized fragmentation functions are known, the need for next-to-leading order calculations, and on how sensitive the asymmetry is to the possible {Delta}g distributions. Vetterli presented HERMES measurements of fragmentation functions, which overlap in Q{sup 2} with the future lower-p{sub T} measurements at RHIC.

  1. RECENT RESULTS WITH AU IONS EXTRACTED FROM AN EBIS USING AN 8A ELECTRON BEAM AT BNL *

    E-Print Network [OSTI]

    Source (EBIS), which is a prototype for an EBIS that could meet requirements for a RHIC preinjector. RHIC INTRODUCTION At Brookhaven National Laboratory an EBIS is being developed to provide gold ions with charge state 32+ sufficient for injection into the Booster without stripping. Requirements for the intensity

  2. ACCELERATION OF ELECTRONS WITH THE RACETRACK NON-SCALING FFAG FOR E-RHIC

    SciTech Connect (OSTI)

    TRBOJEVIC,D.; BLASKIEWICZ, M.; LITVINENKO, V.; PTITSYN, V.; ROSER, T.

    2007-06-25

    The future relativistic electron hadron collider: e-RHIC requires acceleration of electrons to 10 GeV. In the case that the super conducting linac is selected for acceleration, an energy recovery scheme is required. We propose to study a possibility of using the non-scaling Fixed-Field Gradient-Accelerator (NS-FFAG) for different energies. The beam will be accelerated by the superconducting linac at the top of the sine function, brought back to the front of the linac by the non-scaling FFAG and repeating this few times until the total energy of 20 GeV is reached. After collisions the beam is brought back by the non-scaling FFAG and decelerated (on the lower RF phase) in the same sequence but in the reverse order. Conventional and non-conventional beam dynamic issues will be discussed, like the transit time matching effect and the time of flight adjustments.

  3. The Working Group M5 on Lepton-Hadron Colliders Conveners: Ilan Ben-Zvi and Georg H. Hoffstaetter

    E-Print Network [OSTI]

    Hoffstaetter, Georg

    ........................................................................... 28 3. eRHIC, Electron-Hadron Collisions with RHIC

  4. The RHIC SPIN Program: Achievements and Future Opportunities

    E-Print Network [OSTI]

    Elke-Caroline Aschenauer; Alexander Bazilevsky; Markus Diehl; James Drachenberg; Kjeld Oleg Eyser; Renee Fatemi; Carl Gagliardi; Zhongbo Kang; Yuri V. Kovchegov; John Lajoie; Jeong-Hun Lee; Emanuele-R. Nocera; Daniel Pitonyak; Alexei Prokudin; Rodolfo Sassot; Ralf Seidl; Ernst Sichtermann; Matt Sievert; Bernd Surrow; Marco Stratmann; Werner Vogelsang; Anselm Vossen; Scott W. Wissink; Feng Yuan

    2015-01-07

    Time and again, spin has been a key element in the exploration of fundamental physics. Spin-dependent observables have often revealed deficits in the assumed theoretical framework and have led to novel developments and concepts. Spin is exploited in many parity-violating experiments searching for physics beyond the Standard Model or studying the nature of nucleon-nucleon forces. The RHIC spin program plays a special role in this grand scheme: it uses spin to study how a complex many-body system such as the proton arises from the dynamics of QCD. Many exciting results from RHIC spin have emerged to date, most of them from RHIC running after the 2007 Long Range Plan. In this document we present highlights from the RHIC program to date and lay out the roadmap for the significant advances that are possible with future RHIC running.

  5. Exploring the Universe Within

    ScienceCinema (OSTI)

    John Marburger

    2010-01-08

    A guided tour of Brookhaven's Relativistic Heavy Ion Collider (RHIC) conducted by past Laboratory Director John Marburger. RHIC is a world-class scientific research facility that began operation in 2000, following 10 years of development and construction.

  6. Physics Reach at Future Colliders

    SciTech Connect (OSTI)

    Krawczyk, Maria [Institute of Theoretical Physics, University of Warsaw, ul. Hoz-dota 69, 00-681 Warsaw (Poland); CERN, CH-1211 Geneva 23 (Switzerland)

    2007-11-27

    The physics reach at future colliders is discussed, with focus on the Higgs sector. First we present the Standard Model and some results obtained at the existing high-energy hadron collider, Tevatron, together with the corresponding expectations for the Large Hadron Collider (LHC), which starts operating in 2008. Then we discuss important low energy measurements: the anomalous magnetic moment for muon and the leptonic B-decay together with b{yields}s{gamma}. Finally the potential of the planned e{sup +}e{sup -} International Linear Collider (ILC) and its possible option Photon Linear Collider (PLC), e{gamma} and {gamma}{gamma}, is shortly presented.

  7. Construction progress of the RHIC electron lenses

    SciTech Connect (OSTI)

    Fischer W.; Altinbas, Z.; Anerella, M.; Beebe, E.; et al

    2012-05-20

    In polarized proton operation the RHIC performance is limited by the head-on beam-beam effect. To overcome this limitation two electron lenses are under construction. We give an overview of the construction progress. Guns, collectors and the warm electron beam transport solenoids with their power supplies have been constructed. The superconducting solenoids that guide the electron beam during the interaction with the proton beam are near completion. A test stand has been set up to verify the performance of the gun, collector and some of the instrumentation. The infrastructure is being prepared for installation, and simulations continue to optimize the performance.

  8. RHIC spin physics: Proceedings. Volume 7

    SciTech Connect (OSTI)

    1998-12-01

    This proceedings compiles one-page summaries and five transparencies for each talk, with the intention that the speaker should include a web location for additional information in the summary. Also, email addresses are given with the participant list. The order follows the agenda: gluon, polarimetry, accelerator, W production and quark/antiquark polarization, parity violation searches, transversity, single transverse spin, small angle elastic scattering, and the final talk on ep collisions at RHIC. The authors begin the Proceedings with the full set of transparencies from Bob Jaffe`s colloquium on spin, by popular request.

  9. Neutrinos and Collider Physics

    E-Print Network [OSTI]

    Deppisch, Frank F; Pilaftsis, Apostolos

    2015-01-01

    We review the collider phenomenology of neutrino physics and the synergetic aspects at energy, intensity and cosmic frontiers to test the new physics behind the neutrino mass mechanism. In particular, we focus on seesaw models within the minimal setup as well as with extended gauge and/or Higgs sectors, and on supersymmetric neutrino mass models with seesaw mechanism and with $R$-parity violation. In the simplest Type-I seesaw scenario with sterile neutrinos, we summarize and update the current experimental constraints on the sterile neutrino mass and its mixing with the active neutrinos. We also discuss the future experimental prospects of testing the seesaw mechanism at colliders and in related low-energy searches for rare processes, such as lepton flavor violation and neutrinoless double beta decay. The implications of the discovery of lepton number violation at the LHC for leptogenesis are also studied.

  10. Neutrinos and Collider Physics

    E-Print Network [OSTI]

    Frank F. Deppisch; P. S. Bhupal Dev; Apostolos Pilaftsis

    2015-08-04

    We review the collider phenomenology of neutrino physics and the synergetic aspects at energy, intensity and cosmic frontiers to test the new physics behind the neutrino mass mechanism. In particular, we focus on seesaw models within the minimal setup as well as with extended gauge and/or Higgs sectors, and on supersymmetric neutrino mass models with seesaw mechanism and with $R$-parity violation. In the simplest Type-I seesaw scenario with sterile neutrinos, we summarize and update the current experimental constraints on the sterile neutrino mass and its mixing with the active neutrinos. We also discuss the future experimental prospects of testing the seesaw mechanism at colliders and in related low-energy searches for rare processes, such as lepton flavor violation and neutrinoless double beta decay. The implications of the discovery of lepton number violation at the LHC for leptogenesis are also studied.

  11. The International Linear Collider

    E-Print Network [OSTI]

    Karsten Buesser

    2013-06-13

    The International Linear Collider (ILC) is a proposed electron-positron collider for the centre-of-mass energy range of 200 to 500 GeV and with upgrade options towards 1 TeV. The ILC would be the ideal tool to explore with high precision the properties of the new Higgs-like particle that has recently been discovered at the LHC with a mass of around 125 GeV. The ILC accelerator design is based on the mature superconducting technology that has been developed in the TESLA collaboration and that is currently being used for the European XFEL. The exploitation of the huge physics potential of the ILC is a challenge for the design of the ILC detectors.

  12. Quark-Gluon Plasma: a New State of Matter

    ScienceCinema (OSTI)

    Brookhaven Lab

    2010-01-08

    Physicist Peter Steinberg explains the nature of the quark gluon plasma (QGP), a new state of matter produced at Brookhaven Lab's Relativistic Heavy Ion Collider (RHIC).

  13. Baryon Number Fluctuations from a Crossover Equation of State Compared to Heavy-Ion Collision Measurements in the Beam Energy Range $\\sqrt{s_{NN}}$ = 7.7 to 200 GeV

    E-Print Network [OSTI]

    M. Albright; J. Kapusta; C. Young

    2015-06-10

    Fluctuations of the proton number distribution in central Au-Au collisions have been measured by the STAR collaboration in a beam energy scan at the Relativistic Heavy Ion Collider (RHIC). The motivation is a search for evidence of a critical point in the equation of state. It was found that the skewness and kurtosis display an interesting energy dependence. We compare these measurements to an equation of state which smoothly interpolates between an excluded volume hadron resonance gas at low energy density to a perturbative plasma of quarks and gluons at high energy density. This crossover equation of state agrees very well with the lattice QCD equation of state. The crossover equation of state can reproduce the data if the fluctuations are frozen at a temperature significantly lower than the average chemical freeze-out.

  14. Heavy Ion Fusion Science Virtual National Laboratory

    E-Print Network [OSTI]

    to today's large NP accelerators like GSI-FAIR, RHIC economical for 1-2 GWe baseload power plants. Heavy chambers. · Competitive economics: projected in several power plant studies and with no high levelSlide 1 Heavy Ion Fusion Science Virtual National Laboratory Briefing for the National Academy

  15. Cold nuclear matter effects on the color singlet J/psi production in d-Au collisions at RHIC

    E-Print Network [OSTI]

    Zefang Jiang; Shengqin Feng; Zhongbao Yin; Yafei Shi; Xianbao Yuan

    2014-11-13

    We use a Modified DKLMT model (called M-DKLMT model) to study the cold nuclear matter (CNM) effects on the color singlet J/psi production in dAu collisions at RHIC. The cold nuclear effect of dipole-nucleus interactions has been investigated by introducing a nuclear geometric effect function f({\\xi}) to study the nuclear geometry distribution effect in relativistic heavy-ion collisions. The dependencies of nuclear modification factors (RdA) on rapidity and centrality are studied and compared to experimental data. It is found that the M-DKLMT model can well describe the experimental results at both forward- and mid-rapidity regions in dAu collisions at RHIC.

  16. $g_{1}$ at low x and low $Q^{2}$ with Polarized ep Colliders

    E-Print Network [OSTI]

    Bass, S D; Bass, Steven D.; De Roeck, A

    2001-01-01

    Measurements of g_1 at low x and low Q^2 are expected to provide a sensitive probe of the transition from Regge to perturbative QCD dynamics, offering a new testing ground for models of small x physics. We discuss the potential of polarized ep colliders (Polarized HERA and eRHIC) to investigate this physics --- varying Q^2 between 0.01 and 1 GeV^2 --- and to constrain the high-energy part of the Drell-Hearn-Gerasimov sum-rule for polarized photoproduction.

  17. Photoproduction of single inclusive jets at future ep colliders in next-to-leading order QCD

    E-Print Network [OSTI]

    Jäger, B

    2008-01-01

    A next-to-leading order QCD calculation for single-inclusive jet photoproduction in unpolarized and longitudinally polarized lepton-hadron collisions is presented which consistently includes ``direct'' and ``resolved'' photon contributions. The computation is performed within the ``small-cone approximation'' in a largely analytical form. Phenomenological aspects of jet production at future ep colliders such as the CERN-LHeC and the polarized BNL-eRHIC are discussed, placing particular emphasis on the perturbative stability of the predictions and the possibility to constrain the parton content of the photon.

  18. Photoproduction of single inclusive jets at future ep colliders in next-to-leading order QCD

    E-Print Network [OSTI]

    B. Jager

    2008-07-01

    A next-to-leading order QCD calculation for single-inclusive jet photoproduction in unpolarized and longitudinally polarized lepton-hadron collisions is presented which consistently includes ``direct'' and ``resolved'' photon contributions. The computation is performed within the ``small-cone approximation'' in a largely analytical form. Phenomenological aspects of jet production at future ep colliders such as the CERN-LHeC and the polarized BNL-eRHIC are discussed, placing particular emphasis on the perturbative stability of the predictions and the possibility to constrain the parton content of the photon.

  19. g_1 at low x and low Q^2 with Polarized ep Colliders

    E-Print Network [OSTI]

    Steven D. Bass; Albert De Roeck

    2000-08-28

    Measurements of g_1 at low x and low Q^2 are expected to provide a sensitive probe of the transition from Regge to perturbative QCD dynamics, offering a new testing ground for models of small x physics. We discuss the potential of polarized ep colliders (Polarized HERA and eRHIC) to investigate this physics --- varying Q^2 between 0.01 and 1 GeV^2 --- and to constrain the high-energy part of the Drell-Hearn-Gerasimov sum-rule for polarized photoproduction.

  20. Muon Colliders and Neutrino Factories

    SciTech Connect (OSTI)

    Geer, Steve; /Fermilab

    2009-11-01

    Over the past decade, there has been significant progress in developing the concepts and technologies needed to produce, capture, and accelerate {Omicron}(10{sup 21}) muons per year. These developments have paved the way for a new type of neutrino source (neutrino factory) and a new type of very high energy lepton-antilepton collider (muon collider). This article reviews the motivation, design, and research and development for future neutrino factories and muon colliders.

  1. Muon colliders and neutrino factories

    SciTech Connect (OSTI)

    Geer, S.; /Fermilab

    2010-09-01

    Over the last decade there has been significant progress in developing the concepts and technologies needed to produce, capture and accelerate {Omicron}(10{sup 21}) muons/year. This development prepares the way for a new type of neutrino source (Neutrino Factory) and a new type of very high energy lepton-antilepton collider (Muon Collider). This article reviews the motivation, design and R&D for Neutrino Factories and Muon Colliders.

  2. Positrons for linear colliders

    SciTech Connect (OSTI)

    Ecklund, S.

    1987-11-01

    The requirements of a positron source for a linear collider are briefly reviewed, followed by methods of positron production and production of photons by electromagnetic cascade showers. Cross sections for the electromagnetic cascade shower processes of positron-electron pair production and Compton scattering are compared. A program used for Monte Carlo analysis of electromagnetic cascades is briefly discussed, and positron distributions obtained from several runs of the program are discussed. Photons from synchrotron radiation and from channeling are also mentioned briefly, as well as positron collection, transverse focusing techniques, and longitudinal capture. Computer ray tracing is then briefly discussed, followed by space-charge effects and thermal heating and stress due to showers. (LEW)

  3. International Linear Collider Technical Design Report - Volume...

    Office of Scientific and Technical Information (OSTI)

    Technical Report: International Linear Collider Technical Design Report - Volume 2: Physics Citation Details In-Document Search Title: International Linear Collider Technical...

  4. Study of freeze-out dynamics in STAR at RHIC Beam Energy Scan Program

    E-Print Network [OSTI]

    Sabita Das; for the STAR collaboration

    2014-12-01

    The STAR detector at RHIC, due to its large uniform acceptance and excellent particle identification capabilities, has measured a variety of hadron species ($\\pi^{\\pm}$, $K^{\\pm}$, $p$, $\\bar{p}$, $K^{0}_{S}$, $\\Lambda$, $\\bar{\\Lambda}$, $\\Xi^{-}$, $\\bar{\\Xi}^{+}$) produced in Au+Au collisions at $\\sqrt {s_{NN}}= 7.7$, 11.5, 27 and 39 GeV. These data are part of the Beam Energy Scan (BES) program at RHIC and provide an opportunity to measure the yields and transverse momentum spectra ($p_{T}$) of the particles produced in the collisions. The corresponding measurements allow to study the freeze-out properties and dynamics of heavy ion collisions. A statistical thermal model analysis of particle production in BES energies in both grand canonical and strangeness canonical ensembles, is used to extract the chemical freeze-out parameters. The $p_{T}$ spectra, particle ratios, and the energy and centrality dependence of freeze-out parameters determined from the thermal fit of particle ratios are discussed.

  5. The standard model and colliders

    SciTech Connect (OSTI)

    Hinchliffe, I.

    1987-03-01

    Some topics in the standard model of strong and electroweak interactions are discussed, as well as how these topics are relevant for the high energy colliders which will become operational in the next few years. The radiative corrections in the Glashow-Weinberg-Salam model are discussed, stressing how these corrections may be measured at LEP and the SLC. CP violation is discussed briefly, followed by a discussion of the Higgs boson and the searches which are relevant to hadron colliders are then discussed. Some of the problems which the standard model does not solve are discussed, and the energy ranges accessible to the new colliders are indicated. (LEW)

  6. Determination of Dark Matter Properties at High-Energy Colliders

    E-Print Network [OSTI]

    Baltz, Edward A.

    2009-01-01

    at the planned International Linear Collider (ILC) will makecollider, the International Linear Collider (ILC), which

  7. Search for: All records | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    Heavy Ion Collider (RHIC) at Brookhaven Lab and Large Hadron Collider (LHC) in Europe sure can. Quarks and gluons make up protons and neutrons found in the nucleus of every...

  8. Beam collimation at hadron colliders

    SciTech Connect (OSTI)

    Nikolai V. Mokhov

    2003-08-12

    Operational and accidental beam losses in hadron colliders can have a serious impact on machine and detector performance, resulting in effects ranging from minor to catastrophic. Principles and realization are described for a reliable beam collimation system required to sustain favorable background conditions in the collider detectors, provide quench stability of superconducting magnets, minimize irradiation of accelerator equipment, maintain operational reliability over the life of the machine, and reduce the impact of radiation on personnel and the environment. Based on detailed Monte-Carlo simulations, such a system has been designed and incorporated in the Tevatron collider. Its performance, comparison to measurements and possible ways to further improve the collimation efficiency are described in detail. Specifics of the collimation systems designed for the SSC, LHC, VLHC, and HERA colliders are discussed.

  9. Jet production at hadron colliders

    E-Print Network [OSTI]

    Jouttenus, Teppo T. (Teppo Tapani)

    2012-01-01

    Hadronic jets feature in many final states of interest in modern collider experiments. They form a significant Standard Model background for many proposed new physics processes and also probe QCD interactions at several ...

  10. EIS-0138: Superconducting Super Collider

    Broader source: Energy.gov [DOE]

    The U.S. Department of Energy developed this EIS to analyze the potential environmental impacts of constructing the Superconducting Super Collider, a large proton accelerator, at each of seven alternative locations.

  11. System size and energy dependence of high pT hadron production measured with PHENIX experiment at RHIC

    E-Print Network [OSTI]

    Takao Sakaguchi

    2007-03-16

    PHENIX has measured high transverse momentum (pT) identified hadrons in different collision species and energies in the last five RHIC runs. The systematic study of the high pT hadron production provides an idea on interaction of hard scattered partons and the matter created in relativistic heavy ion collision. The eta/pi0 ratio is measured in Au+Au collisions, which gives a hint on the system thermalization and particle production. A future measurement of hadron and photon measurement is discussed.

  12. Systematics of the charged-hadron P_T spectrum and the nuclear suppression factor in heavy-ion collisions from sqrt{s}=200 GeV to sqrt{s} =2.76 TeV

    E-Print Network [OSTI]

    Thorsten Renk; Hannu Holopainen; Risto Paatelainen; Kari J. Eskola

    2011-06-01

    In this paper, our goal is to make a simultaneous analysis of the high- and low-P_T parts of the charged-hadron P_T spectrum measured by the ALICE collaboration in central Pb-Pb collisions at sqrt{s}=2.76 TeV at the Large Hadron Collider (LHC), based on models which have been successfully applied and constrained in Au-Au collisions at Relativistic Heavy Ion Collider (RHIC). For the hydrodynamical modeling with which we obtain the low-P_T spectrum, we have computed the initial conditions based on perturbative QCD (pQCD) minijet production and saturation. The sensitivity of the obtained charged-hadron P_T spectrum on the hydrodynamic model parameters is studied. For the high-P_T part, we apply a number of parton-medium interaction models, which are tuned to describe the nuclear suppression factor R_AA measured at the RHIC in central Au-Au collisions at sqrt{s}=200 GeV. We find that the higher kinematic reach of the LHC, manifest in the hardening of the pQCD parton spectral slope, is in principle very efficient in discriminating the various models. However, due to the uncertainties in the p-p baseline, none of the tested models can be firmly ruled out with the present ALICE data. Comparison with the LHC data in this approach also shows that the matching of the hydrodynamic and pQCD+jet quenching components leaves fairly little room for other hadron production mechanisms in the cross-over region P_T=4-5 GeV.

  13. Hard and soft probe - medium interactions in a 3D hydro+micro approach at RHIC

    E-Print Network [OSTI]

    Bass, S A; Ruppert, J; Nonaka, C

    2007-01-01

    We utilize a 3D hybrid hydro+micro model for a comprehensive and consistent description of soft and hard particle production in ultra-relativistic heavy-ion collisions at RHIC. In the soft sector we focus on the dynamics of (multi-)strange baryons, where a clear strangeness dependence of their collision rates and freeze-out is observed. In the hard sector we study the radiative energy loss of hard partons in a soft medium in the multiple soft scattering approximation. While the nuclear suppression factor $R_{AA}$ does not reflect the high quality of the medium description (except in a reduced systematic uncertainty in extracting the quenching power of the medium), the hydrodynamical model also allows to study different centralities and in particular the angular variation of $R_{AA}$ with respect to the reaction plane, allowing for a controlled variation of the in-medium path-length.

  14. LHC beam-beam compensation studies at RHIC

    SciTech Connect (OSTI)

    Fischer,W.; Abreu, N.; Calaga, R.; Robert-Demolaize, G.; Luo, Y.; Montag, C.

    2009-05-04

    Long-range and head-on beam-beam effects are expected to limit the LHC performance with design parameters. To mitigate long-range effects current carrying wires parallel to the beam were proposed. Two such wires are installed in RHIC where they allow studying the effect of strong long-range beam-beam effects, as well as the compensation of a single long-range interaction. The tests provide benchmark data for simulations and analytical treatments. To reduce the head-on beam-beam effect electron lenses were proposed for both the LHC and RHIC. We present the experimental long-range beam-beam program and report on head-on compensations studies at RHIC, which are based on simulations.

  15. Transverse impedance measurement in RHIC and the AGS

    SciTech Connect (OSTI)

    Biancacci, Nicolo; Blaskiewicz, M.; Dutheil, Y.; Liu, C.; Mernick, M.; Minty, M.; White, S. M.

    2014-05-12

    The RHIC luminosity upgrade program aims for an increase of the polarized proton luminosity by a factor 2. To achieve this goal a significant increase in the beam intensity is foreseen. The beam coupling impedance could therefore represent a source of detrimental effects for beam quality and stability at high bunch intensities. For this reason it is essential to quantify the accelerator impedance budget and the major impedance sources, and possibly cure them. In this MD note we summarize the results of the 2013 transverse impedance measurements in the AGS and RHIC. The studies have been performed measuring the tune shift as a function of bunch intensity and deriving the total accelerator machine transverse impedance. For RHIC, we could obtain first promising results of impedance localization measurements as well.

  16. An alternative model of jet suppression at RHIC energies

    E-Print Network [OSTI]

    Lietava, R; Pisútová, N; Tomasik, Boris; Lietava, Roman; Pisut, Jan; Pisutova, Neva; Tomasik, Boris

    2003-01-01

    We propose a simple Glauber-type mechanism for suppression of jet production up to transverse momenta of about 10 GeV/c at RHIC. For processes in this kinematic region, the formation time is smaller than the interval between two successive hard partonic collisions and the subsequent collision influences the jet production. Number of jets then roughly scales with the number of participants. Proportionality to the number of binary collisions is recovered for very high transverse momenta. The model predicts suppression of jet production in d+Au collisions at RHIC.

  17. An alternative model of jet suppression at RHIC energies

    E-Print Network [OSTI]

    Roman Lietava; Jan Pisut; Neva Pisutova; Boris Tomasik

    2003-02-10

    We propose a simple Glauber-type mechanism for suppression of jet production up to transverse momenta of about 10 GeV/c at RHIC. For processes in this kinematic region, the formation time is smaller than the interval between two successive hard partonic collisions and the subsequent collision influences the jet production. Number of jets then roughly scales with the number of participants. Proportionality to the number of binary collisions is recovered for very high transverse momenta. The model predicts suppression of jet production in d+Au collisions at RHIC.

  18. Ion bombardment in RF photoguns

    SciTech Connect (OSTI)

    Pozdeyev,E.; Kayran, D.; Litvinenko, V. N.

    2009-05-04

    A linac-ring eRHIC design requires a high-intensity CW source of polarized electrons. An SRF gun is viable option that can deliver the required beam. Numerical simulations presented elsewhere have shown that ion bombardment can occur in an RF gun, possibly limiting lifetime of a NEA GaAs cathode. In this paper, we analytically solve the equations of motion of ions in an RF gun using the ponderomotive potential of the Rf field. We apply the method to the BNL 1/2-cell SRF photogun and demonstrate that a significant portion of ions produced in the gun can reach the cathode if no special precautions are taken. Also, the paper discusses possible mitigation techniques that can reduce the rate of ion bombardment.

  19. Photon and dilepton production in high energy heavy ion collisions

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Sakaguchi, Takao

    2015-05-07

    The recent results on direct photons and dileptons in high energy heavy ion collisions, obtained particularly at RHIC and LHC are reviewed. The results are new not only in terms of the probes, but also in terms of the precision. We shall discuss the physics learned from the results.

  20. Absence of anomalous stopping in heavy ion collisions

    E-Print Network [OSTI]

    A. Capella

    2002-05-21

    We show that the baryon stopping observed in heavy ion collisions both at CERN-SPS and at RHIC can be derived from the one observed in proton-proton collisions. No increase in the size of the baryon junction component is required between small size $(pp)$ and large size (AA) systems.

  1. A THEORY UPGRADE FOR RHIC: Towards a Quantitative Understanding of

    E-Print Network [OSTI]

    Gustafsson, Torgny

    is of an enabling nature, comparable to the construction and upgrades of facilities and instruments which enable #12;I. The Challenge The RHIC facility provides a unique environment for studying QCD bulk matter, suggesting a strongly coupled medium. Third, large domains in parameter space for the equation of state have

  2. TEST EBIS Operation and Component Development for the RHIC EBIS

    E-Print Network [OSTI]

    and silicon, which are extracted directly from the Booster ring, the first of three synchrotrons in the RHICTEST EBIS Operation and Component Development for the RHIC EBIS Edward N. Beebe, James G. Alessi, David Graham, Ahovi Kponou, Alexander Pikin, Krsto Prelec, John Ritter, Vladimir Zajic Brookhaven

  3. Mass, Spin, and Physics Beyond the Standard Model at Colliders

    E-Print Network [OSTI]

    Klemm, William Lathrop

    2011-01-01

    Proceedings of 2005 International Linear Collider Workshop (of Supersymmetry,” International Linear Collider Workshop (proposed for the International Linear Collider (ILC), it was

  4. Multi-Stage Bunch Compressors for the International Linear Collider

    E-Print Network [OSTI]

    Tenenbaum, Peter G.; Raubenheimer, Tor O.; Wolski, Andrzej

    2005-01-01

    FOR THE INTERNATIONAL LINEAR COLLIDER ? P. Tenenbaum † ,goals, the International Linear Collider (ILC) requires acompressors for the International Linear Collider. Each of

  5. Recent results in relativistic heavy ion collisions: from ``a new state of matter'' to "the perfect fluid"

    E-Print Network [OSTI]

    M. J. Tannenbaum

    2006-07-28

    Experimental Physics with Relativistic Heavy Ions dates from 1992 when a beam of 197Au of energy greater than 10A GeV/c first became available at the Alternating Gradient Synchrotron (AGS) at Brookhaven National Laboratory (BNL) soon followed in 1994 by a 208Pb beam of 158A GeV/c at the Super Proton Synchrotron (SPS) at CERN (European Center for Nuclear Research). Previous pioneering measurements at the Berkeley Bevalac in the late 1970's and early 1980's were at much lower bombarding energies (~ 1 A GeV/c) where nuclear breakup rather than particle production is the dominant inelastic process in A+A collisions. More recently, starting in 2000, the Relativistic Heavy Ion Collider (RHIC) at BNL has produced head-on collisions of two 100A GeV beams of fully stripped Au ions, corresponding to nucleon-nucleon center-of-mass energy, sqrt(sNN)=200 GeV, total c.m. energy 200A GeV. The objective of this research program is to produce nuclear matter with extreme density and temperature, possibly resulting in a state of matter where the quarks and gluons normally confined inside individual nucleons (r < 1 fm) are free to act over distances an order of magnitude larger. Progress from the period 1992 to the present will be reviewed, with reference to previous results from light ion and proton-proton collisions where appropriate. Emphasis will be placed on the measurements which formed the basis for the announcements by the two major laboratories: "A new state of matter", by CERN on Feb 10, 2000 and "The perfect fluid", by BNL on April 19, 2005.

  6. Measurement of pi0 and eta Mesons with PHENIX in sqrt(s_NN) = 200 GeV Au+Au Collisions at RHIC

    E-Print Network [OSTI]

    B. Sahlmueller; for the PHENIX collaboration

    2008-06-02

    The pi0 meson has been a crucial proble for observing jet quenching in ultrarelativistic heavy-ion collisions at RHIC. Measurements of the eta meson in the same collisions have also shed light on a possible dependence of the observed suppression on the particle species. The preliminary pi0 nuclear modification factor R_AA from the 2004 RHIC run allowed a first systematic comparison between a precise measurement with high statistics and theoretical calculations, constraining model parameters such as the initial gluon density dN^g/dy, and the transport coefficient qhat. The final pi0 spectra and R_AA are shown as well as the first eta results obtained with both PHENIX electromagnetic calorimeters.

  7. Beam-energy dependence of charge separation along the magnetic field in Au+Au collisions at RHIC

    E-Print Network [OSTI]

    STAR Collaboration; L. Adamczyk; J. K. Adkins; G. Agakishiev; M. M. Aggarwal; Z. Ahammed; I. Alekseev; J. Alford; C. D. Anson; A. Aparin; D. Arkhipkin; E. C. Aschenauer; G. S. Averichev; A. Banerjee; D. R. Beavis; R. Bellwied; A. Bhasin; A. K. Bhati; P. Bhattarai; H. Bichsel; J. Bielcik; J. Bielcikova; L. C. Bland; I. G. Bordyuzhin; W. Borowski; J. Bouchet; A. V. Brandin; S. G. Brovko; S. Bültmann; I. Bunzarov; T. P. Burton; J. Butterworth; H. Caines; M. Calderón de la Barca Sánchez; D. Cebra; R. Cendejas; M. C. Cervantes; P. Chaloupka; Z. Chang; S. Chattopadhyay; H. F. Chen; J. H. Chen; L. Chen; J. Cheng; M. Cherney; A. Chikanian; W. Christie; J. Chwastowski; M. J. M. Codrington; G. Contin; J. G. Cramer; H. J. Crawford; X. Cui; S. Das; A. Davila Leyva; L. C. De Silva; R. R. Debbe; T. G. Dedovich; J. Deng; A. A. Derevschikov; R. Derradi de Souza; S. Dhamija; B. di Ruzza; L. Didenko; C. Dilks; F. Ding; P. Djawotho; X. Dong; J. L. Drachenberg; J. E. Draper; C. M. Du; L. E. Dunkelberger; J. C. Dunlop; L. G. Efimov; J. Engelage; K. S. Engle; G. Eppley; L. Eun; O. Evdokimov; O. Eyser; R. Fatemi; S. Fazio; J. Fedorisin; P. Filip; E. Finch; Y. Fisyak; C. E. Flores; C. A. Gagliardi; D. R. Gangadharan; D. Garand; F. Geurts; A. Gibson; M. Girard; S. Gliske; L. Greiner; D. Grosnick; D. S. Gunarathne; Y. Guo; A. Gupta; S. Gupta; W. Guryn; B. Haag; A. Hamed; L-X. Han; R. Haque; J. W. Harris; S. Heppelmann; A. Hirsch; G. W. Hoffmann; D. J. Hofman; S. Horvat; B. Huang; H. Z. Huang; X. Huang; P. Huck; T. J. Humanic; G. Igo; W. W. Jacobs; H. Jang; E. G. Judd; S. Kabana; D. Kalinkin; K. Kang; K. Kauder; H. W. Ke; D. Keane; A. Kechechyan; A. Kesich; Z. H. Khan; D. P. Kikola; I. Kisel; A. Kisiel; D. D. Koetke; T. Kollegger; J. Konzer; I. Koralt; L. K. Kosarzewski; L. Kotchenda; A. F. Kraishan; P. Kravtsov; K. Krueger; I. Kulakov; L. Kumar; R. A. Kycia; M. A. C. Lamont; J. M. Landgraf; K. D. Landry; J. Lauret; A. Lebedev; R. Lednicky; J. H. Lee; M. J. LeVine; C. Li; W. Li; X. Li; X. Li; Y. Li; Z. M. Li; M. A. Lisa; F. Liu; T. Ljubicic; W. J. Llope; M. Lomnitz; R. S. Longacre; X. Luo; G. L. Ma; Y. G. Ma; D. M. M. D. Madagodagettige Don; D. P. Mahapatra; R. Majka; S. Margetis; C. Markert; H. Masui; H. S. Matis; D. McDonald; T. S. McShane; N. G. Minaev; S. Mioduszewski; B. Mohanty; M. M. Mondal; D. A. Morozov; M. K. Mustafa; B. K. Nandi; Md. Nasim; T. K. Nayak; J. M. Nelson; G. Nigmatkulov; L. V. Nogach; S. Y. Noh; J. Novak; S. B. Nurushev; G. Odyniec; A. Ogawa; K. Oh; A. Ohlson; V. Okorokov; E. W. Oldag; D. L. Olvitt Jr.; M. Pachr; B. S. Page; S. K. Pal; Y. X. Pan; Y. Pandit; Y. Panebratsev; T. Pawlak; B. Pawlik; H. Pei; C. Perkins; W. Peryt; P. Pile; M. Planinic; J. Pluta; N. Poljak; K. Poniatowska; J. Porter; A. M. Poskanzer; N. K. Pruthi; M. Przybycien; P. R. Pujahari; J. Putschke; H. Qiu; A. Quintero; S. Ramachandran; R. Raniwala; S. Raniwala; R. L. Ray; C. K. Riley; H. G. Ritter; J. B. Roberts; O. V. Rogachevskiy; J. L. Romero; J. F. Ross; A. Roy; L. Ruan; J. Rusnak; O. Rusnakova; N. R. Sahoo; P. K. Sahu; I. Sakrejda; S. Salur; J. Sandweiss; E. Sangaline; A. Sarkar; J. Schambach; R. P. Scharenberg; A. M. Schmah; W. B. Schmidke; N. Schmitz; J. Seger; P. Seyboth; N. Shah; E. Shahaliev; P. V. Shanmuganathan; M. Shao; B. Sharma; W. Q. Shen; S. S. Shi; Q. Y. Shou; E. P. Sichtermann; R. N. Singaraju; M. J. Skoby; D. Smirnov; N. Smirnov; D. Solanki; P. Sorensen; H. M. Spinka; B. Srivastava; T. D. S. Stanislaus; J. R. Stevens; R. Stock; M. Strikhanov; B. Stringfellow; M. Sumbera; X. Sun; X. M. Sun; Y. Sun; Z. Sun; B. Surrow; D. N. Svirida; T. J. M. Symons; M. A. Szelezniak; J. Takahashi; A. H. Tang; Z. Tang; T. Tarnowsky; J. H. Thomas; A. R. Timmins; D. Tlusty; M. Tokarev; S. Trentalange; R. E. Tribble; P. Tribedy; B. A. Trzeciak; O. D. Tsai; J. Turnau; T. Ullrich; D. G. Underwood; G. Van Buren; G. van Nieuwenhuizen; M. Vandenbroucke; J. A. Vanfossen, Jr.; R. Varma; G. M. S. Vasconcelos; A. N. Vasiliev; R. Vertesi; F. Videbæk; Y. P. Viyogi; S. Vokal; A. Vossen; M. Wada; F. Wang; G. Wang; H. Wang; J. S. Wang; X. L. Wang; Y. Wang; Y. Wang; G. Webb; J. C. Webb; G. D. Westfall; H. Wieman; S. W. Wissink; R. Witt; Y. F. Wu; Z. Xiao; W. Xie; K. Xin; H. Xu; J. Xu; N. Xu; Q. H. Xu; Y. Xu; Z. Xu; W. Yan; C. Yang; Y. Yang; Y. Yang; Z. Ye; P. Yepes; L. Yi; K. Yip; I-K. Yoo; N. Yu; Y. Zawisza; H. Zbroszczyk; W. Zha; J. B. Zhang; J. L. Zhang; S. Zhang; X. P. Zhang; Y. Zhang; Z. P. Zhang; F. Zhao; J. Zhao; C. Zhong; X. Zhu; Y. H. Zhu; Y. Zoulkarneeva; M. Zyzak

    2014-07-15

    Local parity-odd domains are theorized to form inside a Quark-Gluon-Plasma (QGP) which has been produced in high-energy heavy-ion collisions. The local parity-odd domains manifest themselves as charge separation along the magnetic field axis via the chiral magnetic effect (CME). The experimental observation of charge separation has previously been reported for heavy-ion collisions at the top RHIC energies. In this paper, we present the results of the beam-energy dependence of the charge correlations in Au+Au collisions at midrapidity for center-of-mass energies of 7.7, 11.5, 19.6, 27, 39 and 62.4 GeV from the STAR experiment. After background subtraction, the signal gradually reduces with decreased beam energy, and tends to vanish by 7.7 GeV. The implications of these results for the CME will be discussed.

  8. BFKL dynamics at hadron colliders

    E-Print Network [OSTI]

    Carlo Ewerz; Lynne H. Orr; W. James Stirling; Bryan R. Webber

    1999-12-22

    Hadron colliders can provide important tests of BFKL `small-x' dynamics. We discuss two examples of such tests, the inclusive dijet jet cross section at large rapidity separation and the number of associated `mini-jets' in Higgs boson production.

  9. Colliding axisymmetric pp-waves

    E-Print Network [OSTI]

    B. V. Ivanov

    1997-10-21

    An exact solution is found describing the collision of axisymmetric pp-waves with M=0. They are impulsive in character and their coordinate singularities become point curvature singularities at the boundaries of the interaction region. The solution is conformally flat. Concrete examples are given, involving an ultrarelativistic black hole against a burst of pure radiation or two colliding beam- like waves.

  10. Muon Colliders: The Next Frontier

    ScienceCinema (OSTI)

    Tourun, Yagmur [Illinois Institute of Technology, Chicago, Illinois, United States

    2010-01-08

    Muon Colliders provide a path to the energy frontier in particle physics but have been regarded to be "at least 20 years away" for 20 years. I will review recent progress in design studies and hardware R&D and show that a Muon Collider can be established as a real option for the post-LHC era if the current vigorous R&D effort revitalized by the Muon Collider Task Force at Fermilab can be supported to its conclusion. All critical technologies are being addressed and no show-stoppers have emerged. Detector backgrounds have been studied in detail and appear to be manageable and the physics can be done with existing detector technology. A muon facility can be built through a staged scenario starting from a low-energy muon source with unprecedented intensity for exquisite reach for rare processes, followed by a Neutrino Factory with ultrapure neutrino beams with unparalleled sensitivity for disentangling neutrino mixing, leading to an energy frontier Muon Collider with excellent energy resolution.

  11. Physics at high energy photon photon colliders

    SciTech Connect (OSTI)

    Chanowitz, M.S.

    1994-06-01

    I review the physic prospects for high energy photon photon colliders, emphasizing results presented at the LBL Gamma Gamma Collider Workshop. Advantages and difficulties are reported for studies of QCD, the electroweak gauge sector, supersymmetry, and electroweak symmetry breaking.

  12. Proceedings of the International Linear Collider Workshop

    E-Print Network [OSTI]

    Proceedings of the International Linear Collider Workshop LCWS 2007 ILC 2007 Volume 1 Edited by Ariane Frey Sabine Riemann #12;Impressum Proceedings of the International Linear Collider Workshop LCWS

  13. Muon Collider Physics at Very High Energies

    E-Print Network [OSTI]

    M. S. Berger

    2000-01-03

    Muon colliders might greatly extend the energy frontier of collider physics. One can contemplate circular colliders with center-of-mass energies in excess of 10 TeV. Some physics issues that might be relevant at such a machine are discussed.

  14. Multiphase transport model for relativistic nuclear collisions 

    E-Print Network [OSTI]

    Zhang, B.; Ko, Che Ming; Li, Ba; Lin, ZW.

    2000-01-01

    To study heavy ion collisions at energies available from the Relativistic Heavy Ion Collider (RHIC), we have developed a multiphase transport model that includes both initial partonic and final hadronic interactions. ...

  15. Nuclear effects on hadron production in d plus Au collisions at root S(NN)=200 GeV revealed by comparison with p plus p data 

    E-Print Network [OSTI]

    Adler, S. S.; Afanasiev, S.; Aidala, C.; Ajitanand, N. N.; Akiba, Y.; Al-Jamel, A.; Alexander, J.; Aoki, K.; Aphecetche, L.; Armendariz, R.; Aronson, S. H.; Averbeck, R.; Awes, T. C.; Babintsev, V.; Baldisseri, A.; Barish, K. N.; Barnes, P. D.; Bassalleck, B.; Bathe, S.; Batsouli, S.; Baublis, V.; Bauer, F.; Bazilevsky, A.; Belikov, S.; Bjorndal, M. T.; Boissevain, J. G.; Borel, H.; Brooks, M. L.; Brown, D. S.; Bruner, N.; Bucher, D.; Buesching, H.; Bumazhnov, V.; Bunce, G.; Burward-Hoy, J. M.; Butsyk, S.; Camard, X.; Chand, P.; Chang, W. C.; Chernichenko, S.; Chi, C. Y.; Chiba, J.; Chiu, M.; Choi, I. J.; Choudhury, R. K.; Chujo, T.; Cianciolo, V.; Cobigo, Y.; Cole, B. A.; Comets, M. P.; Constantin, P.; Csanad, M.; Csorgo, T.; Cussonneau, J. P.; d'Enterria, D.; Das, K.; David, G.; Deak, F.; Delagrange, H.; Denisov, A.; Deshpande, A.; Desmond, E. J.; Devismes, A.; Dietzsch, O.; Drachenberg, J. L.; Drapier, O.; Drees, A.; Durum, A.; Dutta, D.; Dzhordzhadze, V.; Efremenko, Y. V.; En'yo, H.; Espagnon, B.; Esumi, S.; Fields, D. E.; Finck, C.; Fleuret, F.; Fokin, S. L.; Fox, B. D.; Fraenkel, Z.; Frantz, J. E.; Franz, A.; Frawley, A. D.; Fukao, Y.; Fung, S. -Y; Gadrat, S.; Germain, M.; Glenn, A.; Gonin, M.; Gosset, J.; Goto, Y.; de Cassagnac, R. Granier; Grau, N.; Greene, S. V.; Perdekamp, M. Grosse; Gustafsson, H. -A; Hachiya, T.; Haggerty, J. S.; Hamagaki, H.; Hansen, A. G.; Hartouni, E. P.; Harvey, M.; Hasuko, K.; Hayano, R.; He, X.; Heffner, M.; Hemmick, T. K.; Heuser, J. M.; Hidas, P.; Hiejima, H.; Hill, J. C.; Hobbs, R.; Holzmann, W.; Homma, K.; Hong, B.; Hoover, A.; Horaguchi, T.; Ichihara, T.; Ikonnikov, V. V.; Imai, K.; Inaba, M.; Inuzuka, M.; Isenhower, D.; Isenhower, L.; Ishihara, M.; Issah, M.; Isupov, A.; Jacak, B. V.; Jia, J.; Jinnouchi, O.; Johnson, B. M.; Johnson, S. C.; Joo, K. S.; Jouan, D.; Kajihara, F.; Kametani, S.; Kamihara, N.; Kaneta, M.; Kang, J. H.; Katou, K.; Kawabata, T.; Kazantsev, A. V.; Kelly, S.; Khachaturov, B.; Khanzadeev, A.; Kikuchi, J.; Kim, D. J.; Kim, E.; Kim, G. -B; Kim, H. J.; Kinney, E.; Kiss, A.; Kistenev, E.; Kiyomichi, A.; Klein-Boesing, C.; Kobayashi, H.; Kochenda, L.; Kochetkov, V.; Kohara, R.; Komkov, B.; Konno, M.; Kotchetkov, D.; Kozlov, A.; Kroon, P. J.; Kuberg, C. H.; Kunde, G. J.; Kurita, K.; Kweon, M. J.; Kwon, Y.; Kyle, G. S.; Lacey, R.; Lajoie, J. G.; Le Bornec, Y.; Lebedev, A.; Leckey, S.; Lee, D. M.; Leitch, M. J.; Leite, M. A. L.; Li, X. H.; Lim, H.; Litvinenko, A.; Liu, M. X.; Maguire, C. F.; Makdisi, Y. I.; Malakhov, A.; Manko, V. I.; Mao, Y.; Martinez, G.; Masui, H.; Matathias, F.; Matsumoto, T.; McCain, M. C.; McGaughey, P. L.; Miake, Y.; Miller, T. E.; Milov, A.; Mioduszewski, Saskia; Mishra, G. C.; Mitchell, J. T.; Mohanty, A. K.; Morrison, D. P.; Moss, J. M.; Mukhopadhyay, D.; Muniruzzaman, M.; Nagamiya, S.; Nagle, J. L.; Nakamura, T.; Newby, J.; Nyanin, A. S.; Nystrand, J.; O'Brien, E.; Ogilvie, C. A.; Ohnishi, H.; Ojha, I. D.; Okada, H.; Okada, K.; Oskarsson, A.; Otterlund, I.; Oyama, K.; Ozawa, K.; Pal, D.; Palounek, A. P. T.; Pantuev, V.; Papavassiliou, V.; Park, J.; Park, W. J.; Pate, S. F.; Pei, H.; Penev, V.; Peng, J. -C; Pereira, H.; Peresedov, V.; Pierson, A.; Pinkenburg, C.; Pisani, R. P.; Purschke, M. L.; Purwar, A. K.; Qualls, J. M.; Rak, J.; Ravinovich, I.; Read, K. F.; Reuter, M.; Reygers, K.; Riabov, V.; Riabov, Y.; Roche, G.; Romana, A.; Rosati, M.; Rosendahl, S. S. E.; Rosnet, P.; Rykov, V. L.; Ryu, S. S.; Saito, N.; Sakaguchi, T.; Sakai, S.; Samsonov, V.; Sanfratello, L.; Santo, R.; Sato, H. D.; Sato, S.; Sawada, S.; Schutz, Y.; Semenov, V.; Seto, R.; Shea, T. K.; Shein, I.; Shibata, T. -A; Shigaki, K.; Shimomura, M.; Sickles, A.; Silva, C. L.; Silvermyr, D.; Sim, K. S.; Soldatov, A.; Soltz, R. A.; Sondheim, W. E.; Sorensen, S. P.; Sourikova, I. V.; Staley, F.; Stankus, P. W.; Stenlund, E.; Stepanov, M.; Ster, A.; Stoll, S. P.; Sugitate, T.; Sullivan, J. P.; Takagi, S.; Takagui, E. M.; Taketani, A.; Tanaka, K. H.; Tanaka, Y.; Tanida, K.; Tannenbaum, M. J.; Taranenko, A.; Tarjan, P.; Thomas, T. L.; Togawa, M.; Tojo, J.; Torii, H.; Towell, R. S.; Tram, V-N; Tserruya, I.; Tsuchimoto, Y.; Tydesjo, H.; Tyurin, N.; Uam, T. J.; van Hecke, H. W.; Velkovska, J.; Velkovsky, M.; Veszpremi, V.; Vinogradov, A. A.; Volkov, M. A.; Vznuzdaev, E.; Wang, X. R.; Watanabe, Y.; White, S. N.; Willis, N.; Wohn, F. K.; Woody, C. L.; Xie, W.; Yanovich, A.; Yokkaichi, S.; Young, G. R.; Yushmanov, I. E.; Zajc, W. A.; Zhang, C.; Zhou, S.; Zimanyi, J.; Zolin, L.; Zong, X.; PHENIX Collaboration.

    2006-01-01

    To study heavy ion collisions at energies available from the Relativistic Heavy Ion Collider (RHIC), we have developed a multiphase transport model that includes both initial partonic and final hadronic interactions. ...

  16. Study of QGP with probes associated with photon at RHIC-PHENIX

    E-Print Network [OSTI]

    Yoki Aramaki; for the PHENIX Collaboration

    2009-06-12

    When heavy ions with high energy collide, a hot and dense matter is produced. As the matter expands, the matter undergoes cross-over phase transition from partonic matter to hadronic matter. Jets are created by high pT partons in the early phase of the collisions. Leptons and photons can penetrate the matter without strong interaction. For that reason, jets, leptons and photons are good probes to study the partonic matter in the early phase of the collisions. We report about two probes associated with photon and their results for PHENIX.

  17. Reduction of beta* and increase of luminosity at RHIC

    SciTech Connect (OSTI)

    Pilat,F.; Bai, M.; Bruno, D.; Cameron, P.; Della Penna, A.; Drees, A.; Litvinenko, V.; Luo, Y.; Malitsky, N.; Marr, G.; Ptitsyn, V.; Satogata, T.; Tepikian, S.; Trbojevic, D.

    2009-05-04

    The reduction of {beta}* beyond the 1m design value at RHIC has been consistently achieved over the last 6 years of RHIC operations, resulting in an increase of luminosity for different running modes and species. During the recent 2007-08 deuteron-gold run the reduction to 0.70 from the design 1m achieved a 30% increase in delivered luminosity. The key ingredients allowing the reduction have been the capability of efficiently developing ramps with tune and coupling feedback, orbit corrections on the ramp, and collimation, to minimize beam losses in the final focus triplets, the main aperture limitations for the collision optics. We will describe the operational strategy used to reduce the {beta}*, at first squeezing the beam at store, to test feasibility, followed by the operationally preferred option of squeezing the beam during acceleration, and the resulting luminosity increase. We will conclude with future plans for the beta squeeze.

  18. Absolute beam emittance measurements at RHIC using ionization profile monitors

    SciTech Connect (OSTI)

    Minty, M.; Connolly, R; Liu, C.; Summers, T.; Tepikian, S.

    2014-08-15

    In the past, comparisons between emittance measurements obtained using ionization profile monitors, Vernier scans (using as input the measured rates from the zero degree counters, or ZDCs), the polarimeters and the Schottky detectors evidenced significant variations of up to 100%. In this report we present studies of the RHIC ionization profile monitors (IPMs). After identifying and correcting for two systematic instrumental errors in the beam size measurements, we present experimental results showing that the remaining dominant error in beam emittance measurements at RHIC using the IPMs was imprecise knowledge of the local beta functions. After removal of the systematic errors and implementation of measured beta functions, precise emittance measurements result. Also, consistency between the emittances measured by the IPMs and those derived from the ZDCs was demonstrated.

  19. 423rd Brookhaven Lecture

    ScienceCinema (OSTI)

    Mei Bai

    2010-09-01

    Among other things, scientists at BNL's Relativistic Heavy Ion Collider (RHIC) are studying a fundamental question of particle physics: What is responsible for proton "spin"? Physicist Mei Bai discusses this topic at the 423rd Brookhaven Lecture, "RHIC: The Worlds First High-Energy, Polarized-Proton Collider."

  20. Conventional power sources for colliders

    SciTech Connect (OSTI)

    Allen, M.A.

    1987-07-01

    At SLAC we are developing high peak-power klystrons to explore the limits of use of conventional power sources in future linear colliders. In an experimental tube we have achieved 150 MW at 1 ..mu..sec pulse width at 2856 MHz. In production tubes for SLAC Linear Collider (SLC) we routinely achieve 67 MW at 3.5 ..mu..sec pulse width and 180 pps. Over 200 of the klystrons are in routine operation in SLC. An experimental klystron at 8.568 GHz is presently under construction with a design objective of 30 MW at 1 ..mu..sec. A program is starting on the relativistic klystron whose performance will be analyzed in the exploration of the limits of klystrons at very short pulse widths.

  1. Simulations of Gaussian electron guns for RHIC electron lens

    SciTech Connect (OSTI)

    Pikin, A.

    2014-02-28

    Simulations of two versions of the electron gun for RHIC electron lens are presented. The electron guns have to generate an electron beam with Gaussian radial profile of the electron beam density. To achieve the Gaussian electron emission profile on the cathode we used a combination of the gun electrodes and shaping of the cathode surface. Dependence of electron gun performance parameters on the geometry of electrodes and the margins for electrodes positioning are presented.

  2. Shooting string holography of jet quenching at RHIC and LHC

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Ficnar, Andrej; Gubser, Steven S.; Gyulassy, Miklos

    2014-10-13

    We derive a new formula for jet energy loss using finite endpoint momentum shooting strings initial conditions in SYM plasmas to overcome the difficulties of previous falling string holographic scenarios. We apply the new formula to compute the nuclear modification factor RAA and the elliptic flow parameter v2 of light hadrons at RHIC and LHC. We show furthermore that Gauss–Bonnet quadratic curvature corrections to the AdS5 geometry improve the agreement with the recent data.

  3. Systematic Study of Directed Flow at RHIC Energies

    E-Print Network [OSTI]

    Alice C. Mignerey; for the Phobos Collaboration

    2005-10-10

    Directed flow, v1, of charged hardons has been measured in Au-Au collisions at RHIC for center-of-mass energies sqrt(sNN) = 19.6, 130, 62.4, and 200 GeV using the PHOBOS detector. The large acceptance of PHOBOS for charged particles allows measurements over the full range of pseudorapidity |eta| energies. Comparison is made to a mixed harmonic method for the highest energy, and compared to similar results from the STAR collaboration.

  4. STAR Heavy Flavor Tracker Detects Signs of Charm at RHIC | U...

    Office of Science (SC) Website

    STAR Heavy Flavor Tracker Detects Signs of Charm at RHIC Nuclear Physics (NP) NP Home About Research Facilities Science Highlights Benefits of NP Funding Opportunities Nuclear...

  5. Emission characteristics and dynamics of the stagnation layer in colliding laser produced plasmas

    E-Print Network [OSTI]

    Harilal, S. S.

    Emission characteristics and dynamics of the stagnation layer in colliding laser produced plasmas P been investigated using time and space resolved optical emission spectroscopies and spectrally and angularly resolved fast imaging. The emission results highlight a difference in neutral atom and ion

  6. 9-D polarized proton transport in the MEIC figure-8 collider ring: first steps

    SciTech Connect (OSTI)

    Meot, F.; Morozov, V. S.

    2014-10-24

    Spin tracking studies in the MEIC figure-8 collider ion ring are presented, based on a very preliminary design of the lattice. They provide numerical illustrations of some of the aspects of the figure-8 concept, including spin-rotator based spin control, and lay out the path towards a complete spin tracking simulation of a figure-8 ring.

  7. Heavy-Ion Physics with CMS

    E-Print Network [OSTI]

    Aneta Iordanova

    2008-06-06

    This article presents a brief overview of the CMS experiment capabilities to study the hot and dense matter created in relativistic heavy-ion collisions. The CERN Large Hadron Collider will provide collisions of Pb nuclei at 5.5 TeV per nucleon. The CMS heavy ion group has developed a plethora of physics analyses addressing many important aspects of heavy-ion physics in preparation for a competitive and successful program.

  8. A large hadron electron collider at CERN

    SciTech Connect (OSTI)

    Abelleira Fernandez, J. L.

    2015-04-06

    This document provides a brief overview of the recently published report on the design of the Large Hadron Electron Collider (LHeC), which comprises its physics programme, accelerator physics, technology and main detector concepts. The LHeC exploits and develops challenging, though principally existing, accelerator and detector technologies. This summary is complemented by brief illustrations of some of the highlights of the physics programme, which relies on a vastly extended kinematic range, luminosity and unprecedented precision in deep inelastic scattering. Illustrations are provided regarding high precision QCD, new physics (Higgs, SUSY) and eletron-ion physics. The LHeC is designed to run synchronously with the LHC in the twenties and to achieve an integrated luminosity of O(100)fb–1. It will become the cleanest high resolution microscope of mankind and will substantially extend as well as complement the investigation of the physics of the TeV energy scale, which has been enabled by the LHC.

  9. Detector Background at Muon Colliders

    SciTech Connect (OSTI)

    Mokhov, N.V.; Striganov, S.I.; /Fermilab

    2011-09-01

    Physics goals of a Muon Collider (MC) can only be reached with appropriate design of the ring, interaction region (IR), high-field superconducting magnets, machine-detector interface (MDI) and detector. Results of the most recent realistic simulation studies are presented for a 1.5-TeV MC. It is shown that appropriately designed IR and MDI with sophisticated shielding in the detector have a potential to substantially suppress the background rates in the MC detector. The main characteristics of backgrounds are studied.

  10. Tevatron instrumentation: boosting collider performance

    SciTech Connect (OSTI)

    Shiltsev, Vladimir; Jansson, Andreas; Moore, Ronald; /Fermilab

    2006-05-01

    The Tevatron in Collider Run II (2001-present) is operating with six times more bunches, many times higher beam intensities and luminosities than in Run I (1992-1995). Beam diagnostics were crucial for the machine start-up and the never-ending luminosity upgrade campaign. We present the overall picture of the Tevatron diagnostics development for Run II, outline machine needs for new instrumentation, present several notable examples that led to Tevatron performance improvements, and discuss the lessons for the next big machines--LHC and ILC.

  11. Twistor Spinoffs for Collider Physics

    SciTech Connect (OSTI)

    Dixon, Lance

    2005-12-19

    Finding the adding up of Feynman diagrams tedious? Hidden symmetries found in the sums of diagrams suggest there is a better way to predict the results of particle collisions - in the past two years, spin-offs of a new theory, known as the Twistor String Theory, have led to the development of efficient alternatives to Feynman diagrams which can be useful for work at the Tevatron, the LHC and for future research at the International Linear Collider. Come see what this 'twistor' is all about!

  12. Muon Colliders and Neutrino Factories

    E-Print Network [OSTI]

    Daniel M. Kaplan; for the MAP; MICE Collaborations

    2014-12-10

    Muon colliders and neutrino factories are attractive options for future facilities aimed at achieving the highest lepton-antilepton collision energies and precision measurements of Higgs boson and neutrino mixing matrix parameters. The facility performance and cost depend on how well a beam of muons can be cooled. Recent progress in muon cooling design studies and prototype tests nourishes the hope that such facilities could be built starting in the coming decade. The status of the key technologies and their various demonstration experiments is summarized. Prospects "post-P5" are also discussed.

  13. International Workshop on Linear Colliders 2010

    ScienceCinema (OSTI)

    None

    2011-10-06

    IWLC2010 International Workshop on Linear Colliders 2010ECFA-CLIC-ILC joint meeting: Monday 18 October - Friday 22 October 2010Venue: CERN and CICG (International Conference Centre Geneva, Switzerland) This year, the International Workshop on Linear Colliders organized by the European Committee for Future Accelerators (ECFA) will study the physics, detectors and accelerator complex of a linear collider covering both CLIC and ILC options.Contact Workshop Secretariat  IWLC2010 is hosted by CERN

  14. Prospects for Colliders and Collider Physics to the 1 PeV Energy Scale

    E-Print Network [OSTI]

    B. J. King

    2000-05-04

    A review is given of the prospects for future colliders and collider physics at the energy frontier. A proof-of-plausibility scenario is presented for maximizing our progress in elementary particle physics by extending the energy reach of hadron and lepton colliders as quickly and economically as might be technically and financially feasible. The scenario comprises 5 colliders beyond the LHC -- one each of e+e- and hadron colliders and three muon colliders -- and is able to hold to the historical rate of progress in the log-energy reach of hadron and lepton colliders, reaching the 1 PeV constituent mass scale by the early 2040's. The technical and fiscal requirements for the feasibility of the scenario are assessed and relevant long-term R&D projects are identified. Considerations of both cost and logistics seem to strongly favor housing most or all of the colliders in the scenario in a new world high energy physics laboratory

  15. International Linear Collider Technical Design Report - Volume...

    Office of Scientific and Technical Information (OSTI)

    Linear Collider Technical Design Report - Volume 2: Physics Baer, Howard; Barklow, Tim; Fujii, Keisuke; Gao, Yuanning; Hoang, Andre; Kanemura, Shinya; List, Jenny; Logan, Heather...

  16. JLab Supports International Linear Collider Cavity Development...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Supports International Linear Collider Cavity Development Work NEWPORT NEWS, Va. Feb. 12, 2008 - It's not often that major-league baseball and nuclear physics get to share the...

  17. Plenary: Photon-Photon and Electron-Photon Colliders Mayda M. Velasco

    E-Print Network [OSTI]

    electron-positron colliders like the Interna- tional Linear Collider (ILC) and/or Compact LInear Collider

  18. Comparison of the Window-Frame RHIC-abort kicker with C-type Kicker

    SciTech Connect (OSTI)

    Tsoupas, N.; Hahn, H.; Meng, W.; Severance, Michael; McMahan, Brandon

    2014-08-26

    The high intensity proton bunches (~2.5x1011 p/bunch ) circulating in RHIC increase the temperature of the ferrite-made RHIC-abort-kickers above the Curie point; as a result, the kickers cannot provide the required field to abort the beam at the beam dump. A team of experts in the CAD department worked on modifying the design of the window-frame RHIC-abort kicker to minimize the hysteresis losses responsible for the increase of the ferrite’s temperature. In this technical note we report some results from the study of two possible modifications of the window-frame RHIC-abort kicker, and we compare these results with those of a propose C-type RHIC-abort kicker. We also include an Appendix where we describe a method which may further reduce the hysteresis losses of the window-frame kicker.

  19. ACCELERATOR PHYSICS ISSUES FOR FUTURE ELECTRON-ION COLLIDERS

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    be very high in order to avoid excessive power budgets. This requires the use of a superconduct- ing linac. Energy recovery has already been successfully demonstrated at the...

  20. Test of Chemical freeze-out at RHIC

    E-Print Network [OSTI]

    Jun Takahashi; for the STAR Collaboration

    2008-12-22

    We present the results of a systematic test applying statistical thermal model fits in a consistent way for different particle ratios, and different system sizes using the various particle yields measured in the STAR experiment. Comparison between central and peripheral Au+Au and Cu+Cu collisions with data from p+p collisions provides an interesting tool to verify the dependence with the system size. We also present a study of the rapidity dependence of the thermal fit parameters using available data from RHIC in the forward rapidity regions and also using different parameterization for the rapidity distribution of different particles.

  1. K*0(892) and phi(1020) resonance production at RHIC

    E-Print Network [OSTI]

    Lokesh Kumar

    2015-06-27

    The measurement of resonance production in ultrarelativistic heavy-ion collisions provides a glimpse of the hadronic medium properties and its evolution at different stages. Resonances decaying into hadrons are used to estimate the time span and hadronic interaction cross section in the hadronic phase between chemical and kinetic freeze-out. Specifically, the comparison of K*0(892) and phi(1020) resonances is interesting as the lifetimes of these particles differ by about a factor of 10. Moreover, the nuclear modification factor and azimuthal anisotropy measurements of mesonic resonances, which measure parton energy loss in medium and reflect partonic collectivity, can also probe particle-species and mass ordering. The K*0(892) and phi(1020) resonance production at mid-rapidity (|y|<0.5), measured in high energy (Au+Au, Cu+Cu, d+Au and p+p) collisions at RHIC with STAR experiment, reconstructed by their hadronic decay in Kpi and KK, respectively, are discussed. Mesons' spectra, yields, mean transverse momentum, nuclear modification factor, and azimuthal anisotropy are discussed as a function of centrality and collision energy.

  2. Exclusive processes in electron-ion collisions in the dipole formalism

    SciTech Connect (OSTI)

    Cazaroto, E. R.; Navarra, F. S. [Instituto de Fisica, Universidade de Sao Paulo, C.P. 66318, 05314-970 Sao Paulo, SP (Brazil); Carvalho, F. [Departamento de Ciencias Exatas e da Terra, Universidade Federal de Sao Paulo, Campus Diadema, Rua Prof. Artur Riedel, 275, Jd. Eldorado, 09972-270 Diadema, SP (Brazil); Goncalves, V. P. [Instituto de Fisica e Matematica, Universidade Federal de Pelotas, Caixa Postal 354, 96010-900 Pelotas, RS (Brazil)

    2013-03-25

    We compare the predictions of two saturation models for production of vector mesons and of photons in electron-ion collisions. The models considered are the b-CGC and the rcBK. The calculations were made in the kinematical range of the LHeC and of the future eRHIC.

  3. Event simulation for colliders - A basic overview

    E-Print Network [OSTI]

    Christian Reuschle

    2014-11-26

    In this article we will discuss the basic calculational concepts to simulate particle physics events at high energy colliders. We will mainly focus on the physics in hadron colliders and particularly on the simulation of the perturbative parts, where we will in turn focus on the next-to-leading order QCD corrections.

  4. Solenoid and monocusp ion source

    DOE Patents [OSTI]

    Brainard, John Paul (Albuquerque, NM); Burns, Erskine John Thomas (Albuquerque, NM); Draper, Charles Hadley (Albuquerque, NM)

    1997-01-01

    An ion source which generates hydrogen ions having high atomic purity incorporates a solenoidal permanent magnets to increase the electron path length. In a sealed envelope, electrons emitted from a cathode traverse the magnetic field lines of a solenoid and a monocusp magnet between the cathode and a reflector at the monocusp. As electrons collide with gas, the molecular gas forms a plasma. An anode grazes the outer boundary of the plasma. Molecular ions and high energy electrons remain substantially on the cathode side of the cusp, but as the ions and electrons are scattered to the aperture side of the cusp, additional collisions create atomic ions. The increased electron path length allows for smaller diameters and lower operating pressures.

  5. Solenoid and monocusp ion source

    DOE Patents [OSTI]

    Brainard, J.P.; Burns, E.J.T.; Draper, C.H.

    1997-10-07

    An ion source which generates hydrogen ions having high atomic purity incorporates a solenoidal permanent magnets to increase the electron path length. In a sealed envelope, electrons emitted from a cathode traverse the magnetic field lines of a solenoid and a monocusp magnet between the cathode and a reflector at the monocusp. As electrons collide with gas, the molecular gas forms a plasma. An anode grazes the outer boundary of the plasma. Molecular ions and high energy electrons remain substantially on the cathode side of the cusp, but as the ions and electrons are scattered to the aperture side of the cusp, additional collisions create atomic ions. The increased electron path length allows for smaller diameters and lower operating pressures. 6 figs.

  6. Statistical analysis of multipole components in the magnetic field of the RHIC arc regions

    SciTech Connect (OSTI)

    Beebe-Wang,J.; Jain, A.

    2009-05-04

    The existence of multipolar components in the dipole and quadrupole magnets is one of the factors limiting the beam stability in the RHIC operations. Therefore, the statistical properties of the non-linear fields are crucial for understanding the beam behavior and for achieving the superior performance in RHIC. In an earlier work [1], the field quality analysis of the RHIC interaction regions (IR) was presented. Furthermore, a procedure for developing non-linear IR models constructed from measured multipolar data of RHIC IR magnets was described. However, the field quality in the regions outside of the RHIC IR had not yet been addressed. In this paper, we present the statistical analysis of multipolar components in the magnetic fields of the RHIC arc regions. The emphasis is on the lower order components, especially the sextupole in the arc dipole and the 12-pole in the quadrupole magnets, since they are shown to have the strongest effects on the beam stability. Finally, the inclusion of the measured multipolar components data of RHIC arc regions and their statistical properties into tracking models is discussed.

  7. Updates to the International Linear Collider Damping Rings Baseline...

    Office of Scientific and Technical Information (OSTI)

    Updates to the International Linear Collider Damping Rings Baseline Design Citation Details In-Document Search Title: Updates to the International Linear Collider Damping Rings...

  8. Beam-beam Effects of 'Gear-changing' in Ring-Ring Colliders

    E-Print Network [OSTI]

    Hao, Yue; Ptitsyn, Vadim

    2013-01-01

    In ring-ring colliders, the collision frequency determines the bunch structures, e.g. the time between the bunches in both rings should be identical. Because of relatively low relativistic speed of the hadron beam in sub-TeV hadron-hadron- and electron-ions-colliders, scanning the hadron beam's energy would require either a change in the circumference of one of the rings, or a switching of the bunch (harmonic) number in a ring. The later would cause so-called 'gear-changing', i.e. the change of the colliding bunches turn by turn. In this article, we study the difficulties in beam dynamics in this 'gear-changing' scheme.

  9. Ultraviolet energy dependence of particle production sources in relativistic heavy-ion collisions

    E-Print Network [OSTI]

    Georg Wolschin

    2015-01-13

    The energy dependence of particle production sources in relativistic heavy-ion collisions is investigated from RHIC to LHC energies. Whereas charged-hadron production in the fragmentation sources follows a ln(s_NN/s_0) law, particle production in the mid-rapidity gluon-gluon source exhibits a much stronger dependence proportional to ln^3(s_NN/s_0), and becomes dominant between RHIC and LHC energies. The production of particles with pseudorapidities beyond the beam rapidity is also discussed.

  10. The effects of betatron phase advances on beam-beam and its compensation in RHIC

    SciTech Connect (OSTI)

    Luo, Y.; Fischer, W.; Gu, X.; Tepikian, S.; Trbojevic, D.

    2011-03-28

    In this article we perform simulation studies to investigate the effects of betatron phase advances between the beam-beam interaction points on half-integer resonance driving term, second order chromaticty and dynamic aperture in RHIC. The betatron phase advances are adjusted with artificial matrices inserted in the middle of arcs. The lattices for the 2011 RHIC polarized proton (p-p) run and 2010 RHIC Au-Au runs are used in this study. We also scan the betatron phase advances between IP8 and the electron lens for the proposed Blue ring lattice with head-on beam-beam compensation.

  11. On the Future High Energy Colliders

    E-Print Network [OSTI]

    Shiltsev, Vladimir

    2015-01-01

    High energy particle colliders have been in the forefront of particle physics for more than three decades. At present the near term US, European and international strategies of the particle physics community are centered on full exploitation of the physics potential of the Large Hadron Collider (LHC) through its high-luminosity upgrade (HL-LHC). A number of the next generation collider facilities have been proposed and are currently under consideration for the medium and far-future of accelerator-based high energy physics. In this paper we offer a uniform approach to evaluation of various accelerators based on the feasibility of their energy reach, performance potential and cost range.

  12. On the Future High Energy Colliders

    E-Print Network [OSTI]

    Vladimir Shiltsev

    2015-09-28

    High energy particle colliders have been in the forefront of particle physics for more than three decades. At present the near term US, European and international strategies of the particle physics community are centered on full exploitation of the physics potential of the Large Hadron Collider (LHC) through its high-luminosity upgrade (HL-LHC). A number of the next generation collider facilities have been proposed and are currently under consideration for the medium and far-future of accelerator-based high energy physics. In this paper we offer a uniform approach to evaluation of various accelerators based on the feasibility of their energy reach, performance potential and cost range.

  13. Heavy Ion Collisions at the LHC - Last Call for Predictions

    E-Print Network [OSTI]

    S. Abreu; S. V. Akkelin; J. Alam; J. L. Albacete; A. Andronic; D. Antonov; F. Arleo; N. Armesto; I. C. Arsene; G. G. Barnafoldi; J. Barrette; B. Bauchle; F. Becattini; B. Betz; M. Bleicher; M. Bluhm; D. Boer; F. W. Bopp; P. Braun-Munzinger; L. Bravina; W. Busza; M. Cacciari; A. Capella; J. Casalderrey-Solana; R. Chatterjee; L. -W. Chen; J. Cleymans; B. A. Cole; Z. Conesa Del Valle; L. P. Csernai; L. Cunqueiro; A. Dainese; J. Dias de Deus H. -T. Ding; M. Djordjevic; H. Drescher; I. M. Dremin A. Dumitru; A. El; R. Engel; D. d'Enterria; K. J. Eskola; G. Fai; E. G. Ferreiro; R. J. Fries; E. Frodermann; H. Fujii; C. Gale; F. Gelis; V. P. Goncalves; V. Greco; C. Greiner; M. Gyulassy; H. van Hees; U. Heinz; H. Honkanen; W. A. Horowitz; E. Iancu; G. Ingelman; J. Jalilian-Marian; S. Jeon; A. B. Kaidalov; B. Kampfer; Z. -B. Kang; Iu. A. Karpenko; G. Kestin; D. Kharzeev; C. M. Ko; B. Koch; B. Kopeliovich; M. Kozlov; I. Kraus; I. Kuznetsova; S. H. Lee; R. Lednicky; J. Letessier; E. Levin; B. -A. Li; Z. -W. Lin; H. Liu; W. Liu; C. Loizides; I. P. Lokhtin; M. V. T. Machado; L. V. Malinina; A. M. Managadze; M. L. Mangano; M. Mannarelli; C. Manuel; G. Martinez; J. G. Milhano; A. Mocsy; D. Molnar; M. Nardi; J. K. Nayak; H. Niemi; H. Oeschler; J. -Y. Ollitrault; G. Paic; C. Pajares; V. S. Pantuev; G. Papp; D. Peressounko; P. Petreczky; S. V. Petrushanko; F. Piccinini; T. Pierog; H. J. Pirner; S. Porteboeuf; I. Potashnikova; G. Y. Qin; J. -W. Qiu; J. Rafelski; K. Rajagopal; J. Ranft; R. Rapp; S. S. Rasanen; J. Rathsman; P. Rau; K. Redlich; T. Renk; A. H. Rezaeian; D. Rischke; S. Roesler; J. Ruppert; P. V. Ruuskanen; C. A. Salgado; S. Sapeta; I. Sarcevic; S. Sarkar; L. I. Sarycheva; I. Schmidt; A. I. Shoshi; B. Sinha; Yu. M. Sinyukov; A. M. Snigirev; D. K. Srivastava; J. Stachel; A. Stasto; H. Stocker; C. Yu. Teplov; R. L. Thews; G. Torrieri; V. Topor Pop; D. N. Triantafyllopoulos; K. L. Tuchin; S. Turbide; K. Tywoniuk; A. Utermann; R. Venugopalan; I. Vitev; R. Vogt; E. Wang; X. N. Wang; K. Werner; E. Wessels; S. Wheaton; S. Wicks; U. A. Wiedemann; G. Wolschin; B. -W. Xiao; Z. Xu; S. Yasui; E. Zabrodin; K. Zapp; B. Zhang; B. -W. Zhang; H. Zhang; D. Zhou

    2007-11-06

    This writeup is a compilation of the predictions for the forthcoming Heavy Ion Program at the Large Hadron Collider, as presented at the CERN Theory Institute 'Heavy Ion Collisions at the LHC - Last Call for Predictions', held from May 14th to June 10th 2007.

  14. Helium release rates and ODH calculations from RHIC magnet cooling line failure

    SciTech Connect (OSTI)

    Liaw, C.J.; Than, Y.; Tuozzolo, J.

    2011-03-28

    A catastrophic failure of the magnet cooling lines, similar to the LHC superconducting bus failure incident, could discharge cold helium into the RHIC tunnel and cause an Oxygen Deficiency Hazard (ODH) problem. A SINDA/FLUINT{reg_sign} model, which simulated the 4.5K/4 atm helium flowing through the magnet cooling system distribution lines, then through a line break into the insulating vacuum volumes and discharging via the reliefs into the RHIC tunnel, had been developed. Arc flash energy deposition and heat load from the ambient temperature cryostat surfaces are included in the simulations. Three typical areas: the sextant arc, the Triplet/DX/D0 magnets, and the injection area, had been analyzed. Results, including helium discharge rates, helium inventory loss, and the resulting oxygen concentration in the RHIC tunnel area, are reported. Good agreement had been achieved when comparing the simulation results, a RHIC sector depressurization test measurement, and some simple analytical calculations.

  15. Partonic EoS in High-Energy Nuclear Collisions at RHIC

    E-Print Network [OSTI]

    Xu, Nu

    2006-01-01

    Partonic EoS in High-Energy Nuclear Collisions at RHIC Nu Xuproperties. In high-energy nuclear collisions, the term ?owthe early stage of high-energy nuclear collision, both the

  16. Physics studies at a future linear collider 

    E-Print Network [OSTI]

    Tabassam, Hajrah

    2012-06-22

    With the start of the Large Hadron Collider(LHC) at CERN, we will obtain a new understanding of the physics beyond our current limits. New discoveries will be made; but we will require a deeper understanding, which the ...

  17. Future Colliders Beyond the Standard Model

    E-Print Network [OSTI]

    Murayama, Hitoshi

    17 Future Colliders Beyond the Standard Model By the early 1980s there were persuasive arguments the default future of international high energy physics. The LHC project calls for two multipurpose detectors

  18. Colliding cascades model for earthquake prediction

    E-Print Network [OSTI]

    2000-10-12

    on a direct cascade that would deliver energy from the largest size scales ... The general objective of the colliding cascades model has been to reproduce the ..... earthquake and critical phase transitions studied in statistical physics, where the

  19. Structure and Dynamics of Colliding Plasma Jets

    E-Print Network [OSTI]

    Ryutov, D.

    Monoenergetic-proton radiographs of laser-generated, high-Mach-number plasma jets colliding at various angles shed light on the structures and dynamics of these collisions. The observations compare favorably with results ...

  20. Ion source

    DOE Patents [OSTI]

    Leung, Ka-Ngo (Hercules, CA); Ehlers, Kenneth W. (Alamo, CA)

    1984-01-01

    A magnetic filter for an ion source reduces the production of undesired ion species and improves the ion beam quality. High-energy ionizing electrons are confined by the magnetic filter to an ion source region, where the high-energy electrons ionize gas molecules. One embodiment of the magnetic filter uses permanent magnets oriented to establish a magnetic field transverse to the direction of travel of ions from the ion source region to the ion extraction region. In another embodiment, low energy 16 eV electrons are injected into the ion source to dissociate gas molecules and undesired ion species into desired ion species.

  1. Large Scale Computing and Storage Requirements for Nuclear Physics Research

    E-Print Network [OSTI]

    Gerber, Richard A.

    2012-01-01

    electron-ion collider (MEIC, a JLAB concept). The presentbeam-beam simulations for MEIC, RHIC and LHC • Argonneat BNL and also to support MEIC design studies at JLAB. The

  2. Measurement of charged particle multiplicity distribution in Au + Au collisions up to 200 GeV

    E-Print Network [OSTI]

    Sarin, Pradeep, 1975-

    2003-01-01

    Au+Au collisions in the Relativistic Heavy Ion Collider (RHIC) herald a new era of opportunities for studying hadronic matter under conditions of high energy density and nucleon density. The theory of strong interactions, ...

  3. Identified particle production, azimuthal anisotropy, and interferometry measurements in Au+Au collisions at [sqrt]sNN=9.2 GeV

    E-Print Network [OSTI]

    Surrow, Bernd

    We present the first measurements of identified hadron production, azimuthal anisotropy, and pion interferometry from Au+Au collisions below the nominal injection energy at the BNL Relativistic Heavy-Ion Collider (RHIC) ...

  4. Photon Linear Collider Gamma-Gamma Summary

    SciTech Connect (OSTI)

    Gronberg, J

    2012-02-27

    High energy photon - photon collisions can be achieved by adding high average power short-pulse lasers to the Linear Collider, enabling an expanded physics program for the facility. The technology required to realize a photon linear collider continues to mature. Compton back-scattering technology is being developed around the world for low energy light source applications and high average power lasers are being developed for Inertial Confinement Fusion.

  5. Quark-gluon plasma in the early Universe and in ultra-relativistic heavy-ion collisions

    SciTech Connect (OSTI)

    Greco, V.

    2014-05-09

    We briefly give an elementary introduction to the expansion of the Early Universe till when the phase transition of the quark-gluon plasma to a hadronic matter takes place. Then we describe some main element of the study of QGP by mean of ultra-relativistic heavy-ion collisions (uRHIC's)

  6. International linear collider reference design report

    SciTech Connect (OSTI)

    Aarons, G.

    2007-06-22

    The International Linear Collider will give physicists a new cosmic doorway to explore energy regimes beyond the reach of today's accelerators. A proposed electron-positron collider, the ILC will complement the Large Hadron Collider, a proton-proton collider at the European Center for Nuclear Research (CERN) in Geneva, Switzerland, together unlocking some of the deepest mysteries in the universe. With LHC discoveries pointing the way, the ILC -- a true precision machine -- will provide the missing pieces of the puzzle. Consisting of two linear accelerators that face each other, the ILC will hurl some 10 billion electrons and their anti-particles, positrons, toward each other at nearly the speed of light. Superconducting accelerator cavities operating at temperatures near absolute zero give the particles more and more energy until they smash in a blazing crossfire at the centre of the machine. Stretching approximately 35 kilometres in length, the beams collide 14,000 times every second at extremely high energies -- 500 billion-electron-volts (GeV). Each spectacular collision creates an array of new particles that could answer some of the most fundamental questions of all time. The current baseline design allows for an upgrade to a 50-kilometre, 1 trillion-electron-volt (TeV) machine during the second stage of the project. This reference design provides the first detailed technical snapshot of the proposed future electron-positron collider, defining in detail the technical parameters and components that make up each section of the 31-kilometer long accelerator. The report will guide the development of the worldwide R&D program, motivate international industrial studies and serve as the basis for the final engineering design needed to make an official project proposal later this decade.

  7. The Next Linear Collider: NLC2001

    SciTech Connect (OSTI)

    D. Burke et al.

    2002-01-14

    Recent studies in elementary particle physics have made the need for an e{sup +}e{sup -} linear collider able to reach energies of 500 GeV and above with high luminosity more compelling than ever [1]. Observations and measurements completed in the last five years at the SLC (SLAC), LEP (CERN), and the Tevatron (FNAL) can be explained only by the existence of at least one particle or interaction that has not yet been directly observed in experiment. The Higgs boson of the Standard Model could be that particle. The data point strongly to a mass for the Higgs boson that is just beyond the reach of existing colliders. This brings great urgency and excitement to the potential for discovery at the upgraded Tevatron early in this decade, and almost assures that later experiments at the LHC will find new physics. But the next generation of experiments to be mounted by the world-wide particle physics community must not only find this new physics, they must find out what it is. These experiments must also define the next important threshold in energy. The need is to understand physics at the TeV energy scale as well as the physics at the 100-GeV energy scale is now understood. This will require both the LHC and a companion linear electron-positron collider. A first Zeroth-Order Design Report (ZDR) [2] for a second-generation electron-positron linear collider, the Next Linear Collider (NLC), was published five years ago. The NLC design is based on a high-frequency room-temperature rf accelerator. Its goal is exploration of elementary particle physics at the TeV center-of-mass energy, while learning how to design and build colliders at still higher energies. Many advances in accelerator technologies and improvements in the design of the NLC have been made since 1996. This Report is a brief update of the ZDR.

  8. PERFORMANCE SUMMARY OF THE HELICAL MAGNETS FOR RHIC.

    SciTech Connect (OSTI)

    WILLEN,E.; ANERELLA,M.; ESCALLIER,J.; GANETIS,G.; GHOSH,A.; GUPTA,R.; HARRISON,M.; JAIN,A.; MACKAY,W.; MARONE,A.; MURATORE,J.; PLATE,S.; THOMAS,R.; WANDERER,P.; WU,K.C.; OKAMURA,M.

    2003-05-12

    A series of four Snake and eight Rotator superconducting helical magnet assemblies has been built and installed in RHIC to control the polarization of protons during acceleration and storage in that machine. Each of these assemblies consists of four 2.4 m long dipole magnets in each of which the field rotates through 360 degrees along the magnet's length. The magnets were made by winding one millimeter diameter superconducting 7-strand cable into slots milled into thick-walled aluminum tubes. The magnets produce 4 Tesla field at a current of 320 amperes and are quench-protected with 0.050 ohm resistors placed across the winding in each slot. A total of 48 of these 2.4 m magnets has been built, tested and installed. This paper summarizes their quench performance as well as their field uniformity, of which the integral field is the most critical. All magnets reached the required operating field level of 4 T, and the integral field of the magnets was generally about half of the maximum permissible level of 0.050 Tesla meters.

  9. STUDY OF THE RHIC BPM SMA CONNECTOR FAILURE PROBLEM

    SciTech Connect (OSTI)

    LIAW,C.; SIKORA, R.; SCHROEDER, R.

    2007-06-25

    About 730 BPMs are mounted on the RHIC CQS and Triplet super-conducting magnets. Semi-rigid coaxial cables are used to bring the electrical signal from the BPM feedthroughs to the outside flanges. at the ambient temperature. Every year around 10 cables will lose their signals during the operation. The connection usually failed at the warm end of the cable. The problems were either the solder joint failed or the center conductor retracted out of the SMA connector. Finite element analyses were performed to understand the failure mechanism of the solder joint. The results showed that (1) The SMA center conductor can separate from the mating connector due to the thermal retraction. (2) The maximum thermal stress at the warm end solder joint can exceed the material strength of the Pb37/Sn63 solder material and (3) The magnet ramping frequency (-10 Hz), during the machine startup, can possibly resonant the coaxial cable and damage the solder joints, especially when a fracture is initiated. Test results confirmed that by using the silver bearing solder material (a higher strength material) and by crimping the cable at the locations close to the SMA connector (to prevent the center conductor from retracting) can effectively resolve the connector failure problem.

  10. Direct photons measured by the PHENIX experiment at RHIC

    E-Print Network [OSTI]

    Stefan Bathe; for the PHENIX Collaboration

    2006-09-19

    Results from the PHENIX experiment at RHIC on direct photon production in p+p, d+Au, and Au+Au collisions at sqrt(s_NN) = 200 GeV are presented. In p+p collisions, direct photon production at high p_T behaves as expected from perturbative QCD calculations. The p+p measurement serves as a baseline for direct photon production in Au+Au collisions. In d+Au collisions, no effects of cold nuclear matter are found within the large uncertainty of the measurement. In Au+Au collisions, the production of high p_T direct photons scales as expected for particle production in hard scatterings. This supports jet quenching models, which attribute the suppression of high p_T hadrons to the energy loss of fast partons in the medium produced in the collision. Low p_T direct photons, measured via e+e- pairs with small invariant mass, are possibly related to the production of thermal direct photons.

  11. Conceptual design report for the Solenoidal Tracker at RHIC

    SciTech Connect (OSTI)

    The STAR Collaboration

    1992-06-15

    The Solenoidal Tracker At RHIC (STAR) will search for signatures of quark-gluon plasma (QGP) formation and investigate the behavior of strongly interacting matter at high energy density. The emphasis win be the correlation of many observables on an event-by-event basis. In the absence of definitive signatures for the QGP, it is imperative that such correlations be used to identify special events and possible signatures. This requires a flexible detection system that can simultaneously measure many experimental observables. The physics goals dictate the design of star and it`s experiment. To meet the design criteria, tracking, momentum analysis, and particle identification of most of the charged particles at midrapidity are necessary. The tracking must operate in conditions at higher than the expected maximum charged particle multiplicities for central Au + Au collisions. Particle identification of pions/kaons for p < 0.7 GeV/c and kaons/protons for p < 1 GeV/c, as well as measurement of decay particles and reconstruction of secondary vertices will be possible. A two-track resolution of 2 cm at 2 m radial distance from, the interaction is expected. Momentum resolution of {Delta}p/p {approximately} 0.02 at p = 0.1 GeV/c is required to accomplish the physics, and,{Delta}p/p of several percent at p = 10 GeV/c is sufficient to accurately measure the rapidly failing spectra at high Pt and particles from mini-jets and jets.

  12. Conceptual design report for the Solenoidal Tracker at RHIC

    SciTech Connect (OSTI)

    Not Available

    1992-06-15

    The Solenoidal Tracker At RHIC (STAR) will search for signatures of quark-gluon plasma (QGP) formation and investigate the behavior of strongly interacting matter at high energy density. The emphasis win be the correlation of many observables on an event-by-event basis. In the absence of definitive signatures for the QGP, it is imperative that such correlations be used to identify special events and possible signatures. This requires a flexible detection system that can simultaneously measure many experimental observables. The physics goals dictate the design of star and it's experiment. To meet the design criteria, tracking, momentum analysis, and particle identification of most of the charged particles at midrapidity are necessary. The tracking must operate in conditions at higher than the expected maximum charged particle multiplicities for central Au + Au collisions. Particle identification of pions/kaons for p < 0.7 GeV/c and kaons/protons for p < 1 GeV/c, as well as measurement of decay particles and reconstruction of secondary vertices will be possible. A two-track resolution of 2 cm at 2 m radial distance from, the interaction is expected. Momentum resolution of {Delta}p/p {approximately} 0.02 at p = 0.1 GeV/c is required to accomplish the physics, and,{Delta}p/p of several percent at p = 10 GeV/c is sufficient to accurately measure the rapidly failing spectra at high Pt and particles from mini-jets and jets.

  13. Beam instrumentation for the Tevatron Collider

    SciTech Connect (OSTI)

    Moore, Ronald S.; Jansson, Andreas; Shiltsev, Vladimir; /Fermilab

    2009-10-01

    The Tevatron in Collider Run II (2001-present) is operating with six times more bunches and many times higher beam intensities and luminosities than in Run I (1992-1995). Beam diagnostics were crucial for the machine start-up and the never-ending luminosity upgrade campaign. We present the overall picture of the Tevatron diagnostics development for Run II, outline machine needs for new instrumentation, present several notable examples that led to Tevatron performance improvements, and discuss the lessons for future colliders.

  14. Tevatron Collider Program - Physics, Results, Future?

    E-Print Network [OSTI]

    Krzysztof Sliwa

    2012-01-03

    An overview of more than 25 years of the Tevatron Collider program at Fermi National Accelerator Laboratory in Batavia, near Chicago, Illinois, USA, is presented. The physics goals of the program itself, the Tevatron accelerator design characteristics and some of its achievements are described. A selected set of the past and ongoing physics analyses and measurements performed by CDF and D0 collaborations are summarized. Also, in view of the modified plans and schedule of the Large Hadron Collider (LHC) at CERN, the future of the Tevatron program is discussed.

  15. Top quark studies at hadron colliders

    SciTech Connect (OSTI)

    Sinervo, P.K. [Univ. of Toronto, Ontario (Canada)

    1997-01-01

    The techniques used to study top quarks at hadron colliders are presented. The analyses that discovered the top quark are described, with emphasis on the techniques used to tag b quark jets in candidate events. The most recent measurements of top quark properties by the CDF and DO Collaborations are reviewed, including the top quark cross section, mass, branching fractions, and production properties. Future top quark studies at hadron colliders are discussed, and predictions for event yields and uncertainties in the measurements of top quark properties are presented.

  16. Investigation into electron cloud effects in the International Linear Collider positron damping ring

    E-Print Network [OSTI]

    Crittenden, J.?A.

    2014-01-01

    cloud effects in the International Linear Collider positroninstability in the International Linear Collider positronin the proposed International Linear Collider (ILC) [3].

  17. Polarized Ion Beams in Figure-8 Rings of JLab's MEIC

    SciTech Connect (OSTI)

    Derbenev, Yaroslav; Lin, Fanglei; Morozov, Vasiliy; Zhang, Yuhong; Kondratenko, Anatoliy; Kondratenko, M.A.; Filatov, Yury

    2014-07-01

    The Medium-energy Electron-Ion Collider (MEIC) proposed by Jefferson Lab is designed to provide high polarization of both colliding beams. One of the unique features of JLab's MEIC is figure-8 shape of its rings. It allows preservation and control of polarization of all ion species including small-anomalous-magnetic-moment deuterons during their acceleration and storage. The figure-8 design conceptually expands the capability of obtaining polarized high-energy beams in comparison to conventional designs because of its property of having no preferred periodic spin direction. This allows one to control effectively the beam polarization by means of magnetic insertions with small field integrals. We present a complete scheme for preserving the ion polarization during all stages of acceleration and its control in the collider's experimental straights.

  18. 410th Brookhaven Lecture

    ScienceCinema (OSTI)

    Peter Steinberg

    2010-09-01

    In a lecture titled "Hotter, Denser, Faster, Smaller...and Nearly Perfect: What's the Matter at RHIC?", Steinberg discusses the basic physics of the quark-gluon plasma and BNL's Relativistic Heavy Ion Collider, with a focus on several intriguing results from RHIC's recently ended PHOBOS experiment.

  19. Long-Range Pseudorapidity Correlations at High pT in sqrt(S_NN) = 200 GeV Au+Au Collisions with STAR 

    E-Print Network [OSTI]

    Codrington, Martin John Michael

    2012-10-19

    at the Relativistic Heavy Ion Collider (RHIC), and the related discovery of the quenching of the away-side jet in these collisions, the role of jets as key probes of the QGP was re-affirmed. The Solenoidal Tracker At RHIC (STAR) detector system, which is suited...

  20. Long-range beam-beam interactions in RHIC

    E-Print Network [OSTI]

    Sen, Tanaji

    stronger diffusion for protons than for heavier ions (without BB) Particles trapped in islands 2 orders cooled heat sinks - on vertically movable stand (60mm movement) please comment #12;Wolfram Fischer 20

  1. NNLO Benchmarks for Gauge and Higgs Boson Production at TeV Hadron Colliders

    E-Print Network [OSTI]

    S. Alekhin; J. Blümlein; P. Jimenez-Delgado; S. Moch; E. Reya

    2010-11-29

    The inclusive production cross sections for $W^+, W^-$ and $Z^0$-bosons form important benchmarks for the physics at hadron colliders. We perform a detailed comparison of the predictions for these standard candles based on recent next-to-next-to-leading order (NNLO) parton parameterizations and new analyses including the combined HERA data, compare to all available experimental results, and discuss the predictions for present and upcoming RHIC, SPS, Tevatron and LHC energies. The rates for gauge boson production at the LHC can be rather confidently predicted with an accuracy of better than about 10% at NNLO. We also present detailed NNLO predictions for the Higgs boson production cross sections for Tevatron and LHC energies (1.96, 7, 8, 14 TeV), and propose a possible method to monitor the gluon distribution experimentally in the kinematic region close to the mass range expected for the Higgs boson. The production cross sections of the Higgs boson at the LHC are presently predicted with an accuracy of about 10--17%. The inclusion of the NNLO contributions is mandatory for achieving such accuracies since the total uncertainties are substantially larger at NLO.

  2. Precision Measurements at a Muon Collider

    E-Print Network [OSTI]

    S. Dawson

    1995-12-08

    We discuss the potential for making precision measurements of $M_W$ and $M_T$ at a muon collider and the motivations for each measurement. A comparison is made with the precision measurements expected at other facilities. The measurement of the top quark decay width is also discussed.

  3. Physics Case for the International Linear Collider

    E-Print Network [OSTI]

    Keisuke Fujii; Christophe Grojean; Michael E. Peskin; Tim Barklow; Yuanning Gao; Shinya Kanemura; Hyungdo Kim; Jenny List; Mihoko Nojiri; Maxim Perelstein; Roman Poeschl; Juergen Reuter; Frank Simon; Tomohiko Tanabe; Jaehoon Yu; James D. Wells; Hitoshi Murayama; Hitoshi Yamamoto

    2015-06-26

    We summarize the physics case for the International Linear Collider (ILC). We review the key motivations for the ILC presented in the literature, updating the projected measurement uncertainties for the ILC experiments in accord with the expected schedule of operation of the accelerator and the results of the most recent simulation studies.

  4. Physics Case for the International Linear Collider

    E-Print Network [OSTI]

    Fujii, Keisuke; Peskin, Michael E; Barklow, Tim; Gao, Yuanning; Kanemura, Shinya; Kim, Hyungdo; List, Jenny; Nojiri, Mihoko; Perelstein, Maxim; Poeschl, Roman; Reuter, Juergen; Simon, Frank; Tanabe, Tomohiko; Yu, Jaehoon; Wells, James D; Murayama, Hitoshi; Yamamoto, Hitoshi

    2015-01-01

    We summarize the physics case for the International Linear Collider (ILC). We review the key motivations for the ILC presented in the literature, updating the projected measurement uncertainties for the ILC experiments in accord with the expected schedule of operation of the accelerator and the results of the most recent simulation studies.

  5. Jets in Particle Colliders Andrew Wong!

    E-Print Network [OSTI]

    Budker, Dmitry

    Jets in Particle Colliders Andrew Wong! #12;Topics · What are jets? · How are they produced? · What do we use to study jets? #12;What are jets? · Bunch of different jets #12;Pretty picture! #12;What's in a jet? · Hadrons ­ Kaons, Pions, Protons, Neutrons · Leptons ­ Mainly electrons and muons · These have

  6. PHYSICS WITH AND PHYSICS OF COLLIDING ELECTRON BEAMS

    E-Print Network [OSTI]

    Pellegrini, Claudio

    2008-01-01

    contributed so much to the physics of colliding beams, theyto reap so little from the physics with colliding beams.Conference on High-Energy Physics, Vienna" September 1968 (

  7. Exploring Geometries of SRF Cavities for a Future Muon Collider

    E-Print Network [OSTI]

    Geng, Rong-Li

    application of super- conducting RF cavities in a future muon collider. Such RF cavities are expected to workExploring Geometries of SRF Cavities for a Future Muon Collider Rong-Li Geng LEPP, Cornell

  8. AN OPTIMIZED SUPERFERRIC WIGGLER DESIGN FOR THE INTERNATIONAL LINEAR COLLIDER

    E-Print Network [OSTI]

    AN OPTIMIZED SUPERFERRIC WIGGLER DESIGN FOR THE INTERNATIONAL LINEAR COLLIDER DAMPING RINGS Urban ALL RIGHTS RESERVED #12;AN OPTIMIZED SUPERFERRIC WIGGLER DESIGN FOR THE INTERNATIONAL LINEAR Linear Collider (ILC) damping rings. Results from optimizations of the parameters of this wiggler

  9. AN OPTIMIZED SUPERFERRIC WIGGLER DESIGN FOR THE INTERNATIONAL LINEAR COLLIDER

    E-Print Network [OSTI]

    AN OPTIMIZED SUPERFERRIC WIGGLER DESIGN FOR THE INTERNATIONAL LINEAR COLLIDER DAMPING RINGS Urban ALL RIGHTS RESERVED #12; AN OPTIMIZED SUPERFERRIC WIGGLER DESIGN FOR THE INTERNATIONAL LINEAR Linear Collider (ILC) damping rings. Results from optimizations of the parameters of this wiggler

  10. Fluctuations of charge separation perpendicular to the event plane and local parity violation in sqrt(sNN)=200 GeV Au+Au collisions at RHIC

    E-Print Network [OSTI]

    STAR Collaboration; L. Adamczyk; J. K. Adkins; G. Agakishiev; M. M. Aggarwal; Z. Ahammed; I. Alekseev; J. Alford; C. D. Anson; A. Aparin; D. Arkhipkin; E. Aschenauer; G. S. Averichev; J. Balewski; A. Banerjee; Z. Barnovska; D. R. Beavis; R. Bellwied; M. J. Betancourt; R. R. Betts; A. Bhasin; A. K. Bhati; Bhattarai; H. Bichsel; J. Bielcik; J. Bielcikova; L. C. Bland; I. G. Bordyuzhin; W. Borowski; J. Bouchet; A. V. Brandin; S. G. Brovko; E. Bruna; S. Bültmann; I. Bunzarov; T. P. Burton; J. Butterworth; H. Caines; M. Calderón de la Barca Sánchez; D. Cebra; R. Cendejas; M. C. Cervantes; P. Chaloupka; Z. Chang; S. Chattopadhyay; H. F. Chen; J. H. Chen; J. Y. Chen; L. Chen; J. Cheng; M. Cherney; A. Chikanian; W. Christie; P. Chung; J. Chwastowski; M. J. M. Codrington; R. Corliss; J. G. Cramer; H. J. Crawford; X. Cui; S. Das; A. Davila Leyva; L. C. De Silva; R. R. Debbe; T. G. Dedovich; J. Deng; R. Derradi de Souza; S. Dhamija; B. di Ruzza; L. Didenko; Dilks; F. Ding; A. Dion; P. Djawotho; X. Dong; J. L. Drachenberg; J. E. Draper; C. M. Du; L. E. Dunkelberger; J. C. Dunlop; L. G. Efimov; M. Elnimr; J. Engelage; K. S. Engle; G. Eppley; L. Eun; O. Evdokimov; R. Fatemi; S. Fazio; J. Fedorisin; R. G. Fersch; P. Filip; E. Finch; Y. Fisyak; C. E. Flores; C. A. Gagliardi; D. R. Gangadharan; D. Garand; F. Geurts; A. Gibson; S. Gliske; O. G. Grebenyuk; D. Grosnick; Y. Guo; A. Gupta; S. Gupta; W. Guryn; B. Haag; O. Hajkova; A. Hamed; L-X. Han; R. Haque; J. W. Harris; J. P. Hays-Wehle; S. Heppelmann; A. Hirsch; G. W. Hoffmann; D. J. Hofman; S. Horvat; B. Huang; H. Z. Huang; P. Huck; T. J. Humanic; G. Igo; W. W. Jacobs; C. Jena; E. G. Judd; S. Kabana; K. Kang; K. Kauder; H. W. Ke; D. Keane; A. Kechechyan; A. Kesich; D. P. Kikola; J. Kiryluk; I. Kisel; A. Kisiel; D. D. Koetke; T. Kollegger; J. Konzer; I. Koralt; W. Korsch; L. Kotchenda; P. Kravtsov; K. Krueger; I. Kulakov; L. Kumar; R. A. Kycia; M. A. C. Lamont; J. M. Landgraf; K. D. Landry; S. LaPointe; J. Lauret; A. Lebedev; R. Lednicky; J. H. Lee; W. Leight; M. J. LeVine; C. Li; W. Li; X. Li; X. Li; Y. Li; Z. M. Li; L. M. Lima; M. A. Lisa; F. Liu; T. Ljubicic; W. J. Llope; R. S. Longacre; X. Luo; G. L. Ma; Y. G. Ma; D. M. M. D. Madagodagettige Don; D. P. Mahapatra; R. Majka; S. Margetis; C. Markert; H. Masui; H. S. Matis; D. McDonald; T. S. McShane; S. Mioduszewski; M. K. Mitrovski; Y. Mohammed; B. Mohanty; M. M. Mondal; M. G. Munhoz; M. K. Mustafa; M. Naglis; B. K. Nandi; Md. Nasim; T. K. Nayak; J. M. Nelson; L. V. Nogach; J. Novak; G. Odyniec; A. Ogawa; K. Oh; A. Ohlson; V. Okorokov; E. W. Oldag; R. A. N. Oliveira; D. Olson; M. Pachr; B. S. Page; S. K. Pal; Y. X. Pan; Y. Pandit; Y. Panebratsev; T. Pawlak; B. Pawlik; H. Pei; C. Perkins; W. Peryt; P. Pile; M. Planinic; J. Pluta; D. Plyku; N. Poljak; J. Porter; A. M. Poskanzer; C. B. Powell; C. Pruneau; N. K. Pruthi; M. Przybycien; P. R. Pujahari; J. Putschke; H. Qiu; S. Ramachandran; R. Raniwala; S. Raniwala; R. L. Ray; C. K. Riley; H. G. Ritter; J. B. Roberts; O. V. Rogachevskiy; J. L. Romero; J. F. Ross; A. Roy; L. Ruan; J. Rusnak; N. R. Sahoo; P. K. Sahu; I. Sakrejda; S. Salur; A. Sandacz; J. Sandweiss; E. Sangaline; A. Sarkar; J. Schambach; R. P. Scharenberg; A. M. Schmah; B. Schmidke; N. Schmitz; T. R. Schuster; J. Seger; P. Seyboth; N. Shah; E. Shahaliev; M. Shao; B. Sharma; M. Sharma; W. Q. Shen; S. S. Shi; Q. Y. Shou; E. P. Sichtermann; R. N. Singaraju; M. J. Skoby; D. Smirnov; N. Smirnov; D. Solanki; P. Sorensen; U. G. deSouza; H. M. Spinka; B. Srivastava; T. D. S. Stanislaus; J. R. Stevens; R. Stock; M. Strikhanov; B. Stringfellow; A. A. P. Suaide; M. C. Suarez; M. Sumbera; X. M. Sun; Y. Sun; Z. Sun; B. Surrow; D. N. Svirida; T. J. M. Symons; A. Szanto de Toledo; J. Takahashi; A. H. Tang; Z. Tang; L. H. Tarini; T. Tarnowsky; J. H. Thomas; A. R. Timmins; D. Tlusty; M. Tokarev; S. Trentalange; R. E. Tribble; P. Tribedy; B. A. Trzeciak; O. D. Tsai; J. Turnau; T. Ullrich; D. G. Underwood; G. Van Buren; G. van Nieuwenhuizen; J. A. Vanfossen, Jr.; R. Varma; G. M. S. Vasconcelos; R. Vertesi; F. Videbæk; Y. P. Viyogi; S. Vokal; S. A. Voloshin; A. Vossen; M. Wada; M. Walker; F. Wang; G. Wang; H. Wang; J. S. Wang; Q. Wang; X. L. Wang; Y. Wang; G. Webb; J. C. Webb; G. D. Westfall; H. Wieman; S. W. Wissink; R. Witt; Y. F. Wu; Z. Xiao; W. Xie; K. Xin; H. Xu; N. Xu; Q. H. Xu; W. Xu; Y. Xu; Z. Xu; Yan; C. Yang; Y. Yang; Y. Yang; P. Yepes; L. Yi; K. Yip; I-K. Yoo; Y. Zawisza; H. Zbroszczyk; W. Zha; J. B. Zhang; S. Zhang; X. P. Zhang; Y. Zhang; Z. P. Zhang; F. Zhao; J. Zhao; C. Zhong; X. Zhu; Y. H. Zhu; Y. Zoulkarneeva; M. Zyzak

    2013-10-21

    Previous experimental results based on data (15 million events) collected by the STAR detector at RHIC suggest event-by-event charge separation fluctuations perpendicular to the event plane in non-central heavy-ion collisions. Here we present the correlator previously used split into its two component parts to reveal correlations parallel and perpendicular to the event plane. The results are from a high statistics 200 GeV Au+Au collisions data set (57 million events) collected by the STAR experiment. We explicitly count units of charge separation from which we find clear evidence for more charge separation fluctuations perpendicular than parallel to the event plane. We also employ a modified correlator to study the possible P-even background in same and opposite charge correlations, and find that the P-even background may largely be explained by momentum conservation and collective motion.

  11. NUMERICAL STUDIES OF THE FRICTION FORCE FOR THE RHIC ELECTRON COOLER.

    SciTech Connect (OSTI)

    FEDOTOV,A.V.; BEN-ZVI,I.; LITVINENKO, V.

    2005-05-16

    Accurate calculation of electron cooling times requires an accurate description of the dynamical friction force. The proposed RHIC cooler will require {approx}55 MeV electrons, which must be obtained from an RF linac, leading to very high transverse electron temperatures. A strong solenoid will be used to magnetize the electrons and suppress the transverse temperature, but the achievable magnetized cooling logarithm will not be large. In this paper, we explore the magnetized friction force for parameters of the RHIC cooler, using the VORPAL code [l]. VORPAL can simulate dynamical friction and diffusion coefficients directly from first principles [2]. Various aspects of the fiction force are addressed for the problem of high-energy electron cooling in the RHIC regime.

  12. Linear Collider Physics Resource Book Snowmass 2001

    SciTech Connect (OSTI)

    Ronan (Editor), M.T.

    2001-06-01

    The American particle physics community can look forward to a well-conceived and vital program of experimentation for the next ten years, using both colliders and fixed target beams to study a wide variety of pressing questions. Beyond 2010, these programs will be reaching the end of their expected lives. The CERN LHC will provide an experimental program of the first importance. But beyond the LHC, the American community needs a coherent plan. The Snowmass 2001 Workshop and the deliberations of the HEPAP subpanel offer a rare opportunity to engage the full community in planning our future for the next decade or more. A major accelerator project requires a decade from the beginning of an engineering design to the receipt of the first data. So it is now time to decide whether to begin a new accelerator project that will operate in the years soon after 2010. We believe that the world high-energy physics community needs such a project. With the great promise of discovery in physics at the next energy scale, and with the opportunity for the uncovering of profound insights, we cannot allow our field to contract to a single experimental program at a single laboratory in the world. We believe that an e{sup +}e{sup -} linear collider is an excellent choice for the next major project in high-energy physics. Applying experimental techniques very different from those used at hadron colliders, an e{sup +}e{sup -} linear collider will allow us to build on the discoveries made at the Tevatron and the LHC, and to add a level of precision and clarity that will be necessary to understand the physics of the next energy scale. It is not necessary to anticipate specific results from the hadron collider programs to argue for constructing an e{sup +}e{sup -} linear collider; in any scenario that is now discussed, physics will benefit from the new information that e{sup +}e{sup -} experiments can provide. This last point merits further emphasis. If a new accelerator could be designed and built in a few years, it would make sense to wait for the results of each accelerator before planning the next one. Thus, we would wait for the results from the Tevatron before planning the LHC experiments, and wait for the LHC before planning any later stage. In reality accelerators require a long time to construct, and they require such specialized resources and human talent that delay can cripple what would be promising opportunities. In any event, we believe that the case for the linear collider is so compelling and robust that we can justify this facility on the basis of our current knowledge, even before the Tevatron and LHC experiments are done. The physics prospects for the linear collider have been studied intensively for more than a decade, and arguments for the importance of its experimental program have been developed from many different points of view. This book provides an introduction and a guide to this literature. We hope that it will allow physicists new to the consideration of linear collider physics to start from their own personal perspectives and develop their own assessments of the opportunities afforded by a linear collider.

  13. Towards a Future Linear Collider and The Linear Collider Studies at CERN

    ScienceCinema (OSTI)

    None

    2011-10-06

    During the week 18-22 October, more than 400 physicists will meet at CERN and in the CICG (International Conference Centre Geneva) to review the global progress towards a future linear collider. The 2010 International Workshop on Linear Colliders will study the physics, detectors and accelerator complex of a linear collider covering both the CLIC and ILC options. Among the topics presented and discussed will be the progress towards the CLIC Conceptual Design Report in 2011, the ILC Technical Design Report in 2012, physics and detector studies linked to these reports, and an increasing numbers of common working group activities. The seminar will give an overview of these topics and also CERN?s linear collider studies, focusing on current activities and initial plans for the period 2011-16. n.b: The Council Chamber is also reserved for this colloquium with a live transmission from the Main Auditorium.

  14. Druid, displaying root module used for linear collider detectors

    E-Print Network [OSTI]

    Ruan, M

    2015-01-01

    Based on the ROOT TEve/TGeo classes and the standard linear collider data structure, a dedicated linear collider event display has been developed. It supports the latest detector models for both International Linear Collider and Compact Linear Collider as well as the CALICE test beam prototypes. It can be used to visualise event information at the generation, simulation and reconstruction levels. Many options are provided in an intuitive interface. It has been heavily employed in a variety of analyses.

  15. Luminosity Measurement at the International Linear Collider

    E-Print Network [OSTI]

    Iftach Sadeh

    2010-10-28

    The International Linear Collider (ILC) is a proposed electron-positron collider with a center-of-mass energy of 500~GeV, and a peak luminosity of $2 \\cdot 10^{34}~\\mathrm{cm}^{-2}\\mathrm{s}^{-1}$. The ILC will complement the Large Hadron Collider, a proton-proton accelerator, and provide precision measurements, which may help in solving some of the fundamental questions at the frontier of scientific research, such as the origin of mass and the possible existence of new principles of nature. The linear collider community has set a goal to achieve a precision of $10^{-4}$ on the luminosity measurement at the ILC. This may be accomplished by constructing a finely granulated calorimeter, which will measure Bhabha scattering at small angles. The Bhabha cross-section is theoretically known to great precision, yet the rate of Bhabha scattering events, which would be measured by the luminosity detector, will be influenced by beam-beam effects, and by the inherent energy spread of the collider. The electroweak radiative effects can be calculated to high precision and partially checked with events with final state photon radiation by distinguishing between the observable energy deposits of electrons and of photons in the luminosity calorimeter, using a clustering algorithm. In order to achieve the design goal, the geometrical parameters of the calorimeter need to be reevaluated. This must be done in a generalized manner, so as to facilitate future modifications, the need for which is foreseen, due to expected changes in the detector concept. This work demonstrates that the clustering approach is viable, and that a luminosity calorimeter may be designed to match the precision requirements on the luminosity measurement.

  16. CLIC e+e- Linear Collider Studies

    E-Print Network [OSTI]

    Dominik Dannheim; Philippe Lebrun; Lucie Linssen; Daniel Schulte; Frank Simon; Steinar Stapnes; Nobukazu Toge; Harry Weerts; James Wells

    2012-08-07

    This document provides input from the CLIC e+e- linear collider studies to the update process of the European Strategy for Particle Physics. It is submitted on behalf of the CLIC/CTF3 collaboration and the CLIC physics and detector study. It describes the exploration of fundamental questions in particle physics at the energy frontier with a future TeV-scale e+e- linear collider based on the Compact Linear Collider (CLIC) two-beam acceleration technique. A high-luminosity high-energy e+e- collider allows for the exploration of Standard Model physics, such as precise measurements of the Higgs, top and gauge sectors, as well as for a multitude of searches for New Physics, either through direct discovery or indirectly, via high-precision observables. Given the current state of knowledge, following the observation of a \\sim125 GeV Higgs-like particle at the LHC, and pending further LHC results at 8 TeV and 14 TeV, a linear e+e- collider built and operated in centre-of-mass energy stages from a few-hundred GeV up to a few TeV will be an ideal physics exploration tool, complementing the LHC. Two example scenarios are presented for a CLIC accelerator built in three main stages of 500 GeV, 1.4 (1.5) TeV, and 3 TeV, together with the layout and performance of the experiments and accompanied by cost estimates. The resulting CLIC physics potential and measurement precisions are illustrated through detector simulations under realistic beam conditions.

  17. COLLIDING PULSE INJECTION CONTROL IN A LASER-PLASMA ACCELERATOR

    E-Print Network [OSTI]

    Geddes, Cameron Guy Robinson

    COLLIDING PULSE INJECTION CONTROL IN A LASER-PLASMA ACCELERATOR C.G.R. Geddes , G.R. Plateau, M is presented using the beat between two 'collid- ing' laser pulses to kick electrons into the plasma wake laser pulses [12, 13, 14, 15]. In the colliding pulse technique, the ponderomotive force of the beat

  18. Longitudinal emittance measurements in the Booster and AGS during the 2014 RHIC gold run

    SciTech Connect (OSTI)

    Zeno, K.

    2014-08-18

    This note describes longitudinal emittance measurements that were made in the Booster and AGS during the 2014 RHIC Gold run. It also contains an overview of the longitudinal aspects of their setup during this run. Each bunch intended for RHIC is composed of beam from 4 Booster cycles, and there are two of them per AGS cycle. For each of the 8 Booster cycles required to produce the 2 bunches in the AGS, a beam pulse from EVIS is injected into the Booster and captured in four h=4 buckets. Then those bunches are accelerated to a porch where they are merged into 2 bunches and then into 1 bunch.

  19. Linear optics measurements and corrections using an AC dipole in RHIC

    SciTech Connect (OSTI)

    Wang, G.; Bai, M.; Yang, L.

    2010-05-23

    We report recent experimental results on linear optics measurements and corrections using ac dipole. In RHIC 2009 run, the concept of the SVD correction algorithm is tested at injection energy for both identifying the artificial gradient errors and correcting it using the trim quadrupoles. The measured phase beatings were reduced by 30% and 40% respectively for two dedicated experiments. In RHIC 2010 run, ac dipole is used to measure {beta}* and chromatic {beta} function. For the 0.65m {beta}* lattice, we observed a factor of 3 discrepancy between model and measured chromatic {beta} function in the yellow ring.

  20. Off-momentum beta-beat correction in the RHIC proton run

    SciTech Connect (OSTI)

    Luo Y.; Bai, M.; Fischer, W.; Marusic, A.; Mernick, K.; White, S.

    2012-05-20

    In this article, we will review the techniques to measure the off-momentum {beta}-beat and the correction algorithms with the chromatic arc sextupoles in RHIC. We will focus on the measurement and correction of the off-momentum {beta}*-beat at the interaction points. The off-momentum {beta}* is measured with the quadrupole strength change and a high resolution phase lock loop tune meter. The results of off-momentum {beta}* correction performed in a dedicated beam experiment in the 2012 RHIC 250 GeV polarized proton run are presented.

  1. Effects of EoS in viscous hydro+cascade model for the RHIC Beam Energy Scan

    E-Print Network [OSTI]

    Karpenko, Iu; Huovinen, P; Petersen, H

    2016-01-01

    A state-of-the-art 3+1 dimensional cascade + viscous hydro + cascade model vHLLE+UrQMD has been applied to heavy ion collisions in RHIC Beam Energy Scan range $\\sqrt{s_{\\rm NN}}=7.7\\dots 200$ GeV. Based on comparison to available experimental data it was estimated that an effective value of shear viscosity over entropy density ratio $\\eta/s$ in hydrodynamic stage has to decrease from $\\eta/s=0.2$ to $0.08$ as collision energy increases from $\\sqrt{s_{\\rm NN}} = 7.7$ to $39$ GeV, and to stay at $\\eta/s=0.08$ for $39\\le\\sqrt{s_{\\rm NN}}\\le200$ GeV. In this work we show how an equation of state with first order phase transition affects the hydrodynamic evolution at those collision energies and changes the results of the model as compared to "default scenario" with a crossover type EoS from chiral model.

  2. Effects of EoS in viscous hydro+cascade model for the RHIC Beam Energy Scan

    E-Print Network [OSTI]

    Iu. Karpenko; M. Bleicher; P. Huovinen; H. Petersen

    2016-01-05

    A state-of-the-art 3+1 dimensional cascade + viscous hydro + cascade model vHLLE+UrQMD has been applied to heavy ion collisions in RHIC Beam Energy Scan range $\\sqrt{s_{\\rm NN}}=7.7\\dots 200$ GeV. Based on comparison to available experimental data it was estimated that an effective value of shear viscosity over entropy density ratio $\\eta/s$ in hydrodynamic stage has to decrease from $\\eta/s=0.2$ to $0.08$ as collision energy increases from $\\sqrt{s_{\\rm NN}} = 7.7$ to $39$ GeV, and to stay at $\\eta/s=0.08$ for $39\\le\\sqrt{s_{\\rm NN}}\\le200$ GeV. In this work we show how an equation of state with first order phase transition affects the hydrodynamic evolution at those collision energies and changes the results of the model as compared to "default scenario" with a crossover type EoS from chiral model.

  3. Exploring the QCD Phase Structure with Beam Energy Scan in Heavy-ion Collisions

    E-Print Network [OSTI]

    Luo, Xiaofeng

    2016-01-01

    Beam energy scan programs in heavy-ion collisions aim to explore the QCD phase structure at high baryon density. Sensitive observables are applied to probe the signatures of the QCD phase transition and critical point in heavy-ion collisions at RHIC and SPS. Intriguing structures, such as dip, peak and oscillation, have been observed in the energy dependence of various observables. In this paper, an overview is given and corresponding physics implications will be discussed for the experimental highlights from the beam energy scan programs at the STAR, PHENIX and NA61/SHINE experiments. Furthermore, the beam energy scan phase II at RHIC (2019-2020) and other future experimental facilities for studying the physics at low energies will be also discussed.

  4. Status and Promise of Particle Interferometry in Heavy-Ion Collisions

    E-Print Network [OSTI]

    Selemon Bekele; Fabio Braghin; Zbigniew Chajecki; Paul Chung; John G. Cramer; Tamas Csorgo; Hans Eggers; Sean Gavin; Frederique Grassi; Yogiro Hama; Adam Kisiel; Che-Ming Ko; Tomoi Koide; Gastao Krein; Roy Lacey; Richard Lednicky; Michael A. Lisa; Wesley Metzger; Dariusz Miskowiec; Kenji Morita; Sandra S. Padula; Scott Pratt; Wei-Liang Qian; Vladislav Simak; Yuri Sinyukov; Michal Sumbera; Bernardo M. Tavares; Giuseppe Verde; Detlef Zschiesche

    2007-06-06

    After five years of running at RHIC, and on the eve of the LHC heavy-ion program, we highlight the status of femtoscopic measurements. We emphasize the role interferometry plays in addressing fundamental questions about the state of matter created in such collisions, and present an enumerated list of measurements, analyses and calculations that are needed to advance the field in the coming years.

  5. Hydro-inspired parameterizations of freeze-out in relativistic heavy-ion collisions

    E-Print Network [OSTI]

    Wojciech Florkowski; Wojciech Broniowski

    2004-10-19

    Popular parameterizations of the freeze-out conditions in relativistic heavy-ion collisions are discussed. Similarities and differences between the blast-wave model and the single-freeze-out model, both used recently to interpret the RHIC data, are outlined. A non-boost-invariant extension of the single-freeze-out model is proposed and applied to describe the recent BRAHMS data.

  6. Energy Dependence of Moments of Net-proton Multiplicity Distributions at RHIC

    E-Print Network [OSTI]

    STAR Collaboration; L. Adamczyk; J. K. Adkins; G. Agakishiev; M. M. Aggarwal; Z. Ahammed; I. Alekseev; J. Alford; C. D. Anson; A. Aparin; D. Arkhipkin; E. C. Aschenauer; G. S. Averichev; J. Balewski; A. Banerjee; Z. Barnovska; D. R. Beavis; R. Bellwied; A. Bhasin; A. K. Bhati; P. Bhattarai; H. Bichsel; J. Bielcik; J. Bielcikova; L. C. Bland; I. G. Bordyuzhin; W. Borowski; J. Bouchet; A. V. Brandin; S. G. Brovko; S. Bültmann; I. Bunzarov; T. P. Burton; J. Butterworth; H. Caines; M. Calderóndela Barca Sánchez; D. Cebra; R. Cendejas; M. C. Cervantes; P. Chaloupka; Z. Chang; S. Chattopadhyay; H. F. Chen; J. H. Chen; L. Chen; J. Cheng; M. Cherney; A. Chikanian; W. Christie; J. Chwastowski; M. J. M. Codrington; R. Corliss; J. G. Cramer; H. J. Crawford; X. Cui; S. Das; A. Davila Leyva; L. C. De Silva; R. R. Debbe; T. G. Dedovich; J. Deng; A. A. Derevschikov; R. Derradi de Souza; S. Dhamija; B. di Ruzza; L. Didenko; C. Dilks; F. Ding; P. Djawotho; X. Dong; J. L. Drachenberg; J. E. Draper; C. M. Du; L. E. Dunkelberger; J. C. Dunlop; L. G. Efimov; J. Engelage; K. S. Engle; G. Eppley; L. Eun; O. Evdokimov; R. Fatemi; S. Fazio; J. Fedorisin; P. Filip; E. Finch; Y. Fisyak; C. E. Flores; C. A. Gagliardi; D. R. Gangadharan; D. Garand; F. Geurts; A. Gibson; M. Girard; S. Gliske; D. Grosnick; Y. Guo; A. Gupta; S. Gupta; W. Guryn; B. Haag; O. Hajkova; A. Hamed; L-X. Han; R. Haque; J. W. Harris; J. P. Hays-Wehle; S. Heppelmann; A. Hirsch; G. W. Hoffmann; D. J. Hofman; S. Horvat; B. Huang; H. Z. Huang; P. Huck; T. J. Humanic; G. Igo; W. W. Jacobs; H. Jang; E. G. Judd; S. Kabana; D. Kalinkin; K. Kang; K. Kauder; H. W. Ke; D. Keane; A. Kechechyan; A. Kesich; Z. H. Khan; D. P. Kikola; I. Kisel; A. Kisiel; D. D. Koetke; T. Kollegger; J. Konzer; I. Koralt; W. Korsch; L. Kotchenda; P. Kravtsov; K. Krueger; I. Kulakov; L. Kumar; R. A. Kycia; M. A. C. Lamont; J. M. Landgraf; K. D. Landry; J. Lauret; A. Lebedev; R. Lednicky; J. H. Lee; W. Leight; M. J. LeVine; C. Li; W. Li; X. Li; X. Li; Y. Li; Z. M. Li; L. M. Lima; M. A. Lisa; F. Liu; T. Ljubicic; W. J. Llope; R. S. Longacre; X. Luo; G. L. Ma; Y. G. Ma; D. M. M. D. Madagodagettige Don; D. P. Mahapatra; R. Majka; S. Margetis; C. Markert; H. Masui; H. S. Matis; D. McDonald; T. S. McShane; N. G. Minaev; S. Mioduszewski; B. Mohanty; M. M. Mondal; D. A. Morozov; M. G. Munhoz; M. K. Mustafa; B. K. Nandi; Md. Nasim; T. K. Nayak; J. M. Nelson; L. V. Nogach; S. Y. Noh; J. Novak; S. B. Nurushev; G. Odyniec; A. Ogawa; K. Oh; A. Ohlson; V. Okorokov; E. W. Oldag; R. A. N. Oliveira; M. Pachr; B. S. Page; S. K. Pal; Y. X. Pan; Y. Pandit; Y. Panebratsev; T. Pawlak; B. Pawlik; H. Pei; C. Perkins; W. Peryt; A. Peterson; P. Pile; M. Planinic; J. Pluta; D. Plyku; N. Poljak; J. Porter; A. M. Poskanzer; N. K. Pruthi; M. Przybycien; P. R. Pujahari; H. Qiu; A. Quintero; S. Ramachandran; R. Raniwala; S. Raniwala; R. L. Ray; C. K. Riley; H. G. Ritter; J. B. Roberts; O. V. Rogachevskiy; J. L. Romero; J. F. Ross; A. Roy; L. Ruan; J. Rusnak; N. R. Sahoo; P. K. Sahu; I. Sakrejda; S. Salur; A. Sandacz; J. Sandweiss; E. Sangaline; A. Sarkar; J. Schambach; R. P. Scharenberg; A. M. Schmah; W. B. Schmidke; N. Schmitz; J. Seger; P. Seyboth; N. Shah; E. Shahaliev; P. V. Shanmuganathan; M. Shao; B. Sharma; W. Q. Shen; S. S. Shi; Q. Y. Shou; E. P. Sichtermann; R. N. Singaraju; M. J. Skoby; D. Smirnov; N. Smirnov; D. Solanki; P. Sorensen; U. G. deSouza; H. M. Spinka; B. Srivastava; T. D. S. Stanislaus; J. R. Stevens; R. Stock; M. Strikhanov; B. Stringfellow; A. A. P. Suaide; M. Sumbera; X. Sun; X. M. Sun; Y. Sun; Z. Sun; B. Surrow; D. N. Svirida; T. J. M. Symons; A. Szanto de Toledo; J. Takahashi; A. H. Tang; Z. Tang; T. Tarnowsky; J. H. Thomas; A. R. Timmins; D. Tlusty; M. Tokarev; S. Trentalange; R. E. Tribble; P. Tribedy; B. A. Trzeciak; O. D. Tsai; J. Turnau; T. Ullrich; D. G. Underwood; G. Van Buren; G. van Nieuwenhuizen; J. A. Vanfossen, Jr.; R. Varma; G. M. S. Vasconcelos; A. N. Vasiliev; R. Vertesi; F. Videbæk; Y. P. Viyogi; S. Vokal; A. Vossen; M. Wada; M. Walker; F. Wang; G. Wang; H. Wang; J. S. Wang; X. L. Wang; Y. Wang; Y. Wang; G. Webb; J. C. Webb; G. D. Westfall; H. Wieman; S. W. Wissink; R. Witt; Y. F. Wu; Z. Xiao; W. Xie; K. Xin; H. Xu; N. Xu; Q. H. Xu; Y. Xu; Z. Xu; W. Yan; C. Yang; Y. Yang; Y. Yang; Z. Ye; P. Yepes; L. Yi; K. Yip; I-K. Yoo; Y. Zawisza; H. Zbroszczyk; W. Zha; J. B. Zhang; S. Zhang; X. P. Zhang; Y. Zhang; Z. P. Zhang; F. Zhao; J. Zhao; C. Zhong; X. Zhu; Y. H. Zhu; Y. Zoulkarneeva; M. Zyzak

    2013-09-23

    We report the beam energy (\\sqrt s_{NN} = 7.7 - 200 GeV) and collision centrality dependence of the mean (M), standard deviation (\\sigma), skewness (S), and kurtosis (\\kappa) of the net-proton multiplicity distributions in Au+Au collisions. The measurements are carried out by the STAR experiment at midrapidity (|y| < 0.5) and within the transverse momentum range 0.4 < pT < 0.8 GeV/c in the first phase of the Beam Energy Scan program at the Relativistic Heavy Ion Collider. These measurements are important for understanding the Quantum Chromodynamic (QCD) phase diagram. The products of the moments, S\\sigma and \\kappa\\sigma^{2}, are sensitive to the correlation length of the hot and dense medium created in the collisions and are related to the ratios of baryon number susceptibilities of corresponding orders. The products of moments are found to have values significantly below the Skellam expectation and close to expectations based on independent proton and anti-proton production. The measurements are compared to a transport model calculation to understand the effect of acceptance and baryon number conservation, and also to a hadron resonance gas model.

  7. Collider signature of T-quarks

    SciTech Connect (OSTI)

    Carena, Marcela; Hubisz, Jay; /Fermilab; Perelstein, Maxim; /Cornell U., LEPP; Verdier, Patrice; /Lyon, IPN

    2006-10-01

    Little Higgs models with T Parity contain new vector-like fermions, the T-odd quarks or ''T-quarks'', which can be produced at hadron colliders with a QCD-strength cross section. Events with two acoplanar jets and large missing transverse energy provide a simple signature of T-quark production. We show that searches for this signature with the Tevatron Run II data can probe a significant part of the Little Higgs model parameter space not accessible to previous experiments, exploring T-quark masses up to about 400 GeV. This reach covers parts of the parameter space where the lightest T-odd particle can account for the observed dark matter relic abundance. We also comment on the prospects for this search at the Large Hadron Collider (LHC).

  8. Physics at International Linear Collider (ILC)

    E-Print Network [OSTI]

    Hitoshi Yamamoto

    2007-09-06

    International Linear Collider (ILC) is an electron-positron collider with the initial center-of-mass energy of 500 GeV which is upgradable to about 1 TeV later on. Its goal is to study the physics at TeV scale with unprecedented high sensitivities. The main topics include precision measurements of the Higgs particle properties, studies of supersymmtric particles and the underlying theoretical structure if supersymmetry turns out to be realized in nature, probing alternative possibilities for the origin of mass, and the cosmological connections thereof. In many channels, Higgs and leptonic sector in particular, ILC is substantially more sensitive than LHC, and is complementary to LHC overall. In this short article, we will have a quick look at the capabilities of ILC.

  9. Luminosity Spectrum Reconstruction at Linear Colliders

    E-Print Network [OSTI]

    Stéphane Poss; André Sailer

    2014-04-11

    A good knowledge of the luminosity spectrum is mandatory for many measurements at future e+e- colliders. As the beam-parameters determining the luminosity spectrum cannot be measured precisely, the luminosity spectrum has to be measured through a gauge process with the detector. The measured distributions, used to reconstruct the spectrum, depend on Initial State Radiation, cross-section, and Final State Radiation. To extract the basic luminosity spectrum, a parametric model of the luminosity spectrum is created, in this case the spectrum at the 3 TeV Compact Linear Collider (CLIC). The model is used within a reweighting technique to extract the luminosity spectrum from measured Bhabha event observables, taking all relevant effects into account. The centre-of-mass energy spectrum is reconstructed within 5% over the full validity range of the model. The reconstructed spectrum does not result in a significant bias or systematic uncertainty in the exemplary physics benchmark process of smuon pair production.

  10. HBT puzzle at RHIC AMPT model with String Melting

    E-Print Network [OSTI]

    Lin, Zi-wei

    /RsideSmall radii Small duration time dt by Stephen Johnson at RWW02 One way out: Hydro Softest point in EOS Measured extensively in heavy ion collisions reasonably described by models (hydro-ph/01120062 recent hydro studies: #12;HIJING energy in strings(soft) and minijet partons(hard) ZPC (Zhang

  11. The Dark Penguin Shines Light at Colliders

    E-Print Network [OSTI]

    Primulando, Reinard; Tsai, Yuhsin

    2015-01-01

    Collider experiments are one of the most promising ways to constrain Dark Matter (DM) interactions. For several types of DM-Standard Model couplings, a meaningful interpretation of the results requires to go beyond effective field theory, considering simplified models with light mediators. This is especially important in the case of loop-mediated interactions. In this paper we perform the first simplified model study of the magnetic dipole interacting DM, by including the one-loop momentum-dependent form factors that mediate the coupling -- given by the Dark Penguin -- in collider processes. We compute bounds from the monojet, monophoton, and diphoton searches at the $8$ and $14$ TeV LHC, and compare the results to those of direct and indirect detection experiments. Future searches at the $100$ TeV hadron collider and at the ILC are also addressed. We find that the optimal search strategy requires loose cuts on the missing transverse energy, to capture the enhancement of the form factors near the threshold fo...

  12. Structure and Dynamics of Colliding Plasma Jets

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Li, C.; Ryutov, D.; Hu, S.; Rosenberg, M.; Zylstra, A.; Seguin, F.; Frenje, J.; Casey, D.; Gatu Johnson, M.; Manuel, M.; et al

    2013-12-01

    Monoenergetic-proton radiographs of laser-generated, high-Mach-number plasma jets colliding at various angles shed light on the structures and dynamics of these collisions. The observations compare favorably with results from 2D hydrodynamic simulations of multistream plasma jets, and also with results from an analytic treatment of electron flow and magnetic field advection. In collisions of two noncollinear jets, the observed flow structure is similar to the analytic model’s prediction of a characteristic feature with a narrow structure pointing in one direction and a much thicker one pointing in the opposite direction. Spontaneous magnetic fields, largely azimuthal around the colliding jets and generatedmore »by the well-known ?Te ×?ne Biermann battery effect near the periphery of the laser spots, are demonstrated to be “frozen in” the plasma (due to high magnetic Reynolds number RM ~5×10?) and advected along the jet streamlines of the electron flow. These studies provide novel insight into the interactions and dynamics of colliding plasma jets.« less

  13. Structure and Dynamics of Colliding Plasma Jets

    SciTech Connect (OSTI)

    Li, C.; Ryutov, D.; Hu, S.; Rosenberg, M.; Zylstra, A.; Seguin, F.; Frenje, J.; Casey, D.; Gatu Johnson, M.; Manuel, M.; Rinderknecht, H.; Petrasso, R.; Amendt, P.; Park, H.; Remington, B.; Wilks, S.; Betti, R.; Froula, D.; Knauer, J.; Meyerhofer, D.; Drake, R.; Kuranz, C.; Young, R.; Koenig, M.

    2013-12-01

    Monoenergetic-proton radiographs of laser-generated, high-Mach-number plasma jets colliding at various angles shed light on the structures and dynamics of these collisions. The observations compare favorably with results from 2D hydrodynamic simulations of multistream plasma jets, and also with results from an analytic treatment of electron flow and magnetic field advection. In collisions of two noncollinear jets, the observed flow structure is similar to the analytic model’s prediction of a characteristic feature with a narrow structure pointing in one direction and a much thicker one pointing in the opposite direction. Spontaneous magnetic fields, largely azimuthal around the colliding jets and generated by the well-known ?Te ×?ne Biermann battery effect near the periphery of the laser spots, are demonstrated to be “frozen in” the plasma (due to high magnetic Reynolds number RM ~5×10?) and advected along the jet streamlines of the electron flow. These studies provide novel insight into the interactions and dynamics of colliding plasma jets.

  14. Low Mass Vector Meson Measurements via Di-electrons at RHIC by the PHENIX Experiment

    E-Print Network [OSTI]

    Deepali Sharma; for the PHENIX Collaboration

    2009-01-21

    The PHENIX experiment at RHIC has measured $\\omega$ and $\\phi$ mesons in $p+p$, $d+Au$ and $Au+Au$ collisions at \\sqn = 200 GeV via both hadronic and di-electron decay channels. The transverse momentum spectra as measured in different decay modes and at different centralities are shown and discussed here.

  15. Parametrization for chemical freeze-out conditions from net-charge fluctuations measured at RHIC

    E-Print Network [OSTI]

    M. Bluhm; P. Alba; W. Alberico; R. Bellwied; V. Mantovani Sarti; M. Nahrgang; C. Ratti

    2014-12-18

    We discuss details of our thermal model applied to extract chemical freeze-out conditions from fluctuations in the net-electric charge and net-proton number measured at RHIC. A parametrization for these conditions as a function of the beam energy is given.

  16. Wake fields and energy spread for the eRHIC ERL

    SciTech Connect (OSTI)

    Fedotov, A.; Kayran, D.

    2011-10-16

    Wake fields in high-current ERLs can cause significant beam quality degradations. Here we summarize effects of coherent synchrotron radiation, resistive wall, accelerating cavities and wall roughness for ERL parameters of the eRHIC project. A possibility of compensation of such correlated energy spread is also presented. An emphasis in the discussion is made on the suppression of coherent synchrotron radiation due to shielding and a possible reduction of wall roughness effects for realistic surfaces. In this report we discuss the wake fields with a focus on their effect on the energy spread of the beam. Other effects of wake fields are addressed elsewhere. An energy spread builds up during a pass though a very long beam transport in the eRHIC ERL under design. Such energy spread become important when beam is decelerated to low energy, and needs to be corrected. Several effects, such as Coherent Synchrotron Radiation (CSR), Resistive Wall (RW), accelerating RF cavities (RF) and Wall Roughness (WR) were considered. In this paper, we briefly summarize major contributions to energy spread from the wake fields for eRHIC parameters, and present possible energy spread compensation for decelerated beam. In the rest of the report we discuss effects which we believe are suppressed for the eRHIC parameters.

  17. Higher order QED in high mass e+ e- pairs production at RHIC

    E-Print Network [OSTI]

    Anthony J. Baltz; Joakim Nystrand

    2010-03-19

    Lowest order and higher order QED calculations have been carried out for the RHIC high mass e+ e- pairs observed by PHENIX with single ZDC triggers. The lowest order QED results for the experimental acceptance are about two standard deviations larger than the PHENIX data. Corresponding higher order QED calculations are within one standard deviation of the data.

  18. Electron lenses for compensation of beam-beam effects: Tevatron, RHIC, LHC

    SciTech Connect (OSTI)

    Shiltsev, V.; /Fermilab

    2007-12-01

    Since previous BEAM'06 workshop a year ago, significant progress has been made in the field of beam-beam compensation (BBC)--it has been experimentally demonstrated that both Tevatron Electron Lenses (TEL) significantly improve proton and luminosity lifetimes in high-luminosity stores. This article summarizes these results and discusses prospects of the BBC in Tevatron, RHIC and LHC.

  19. Rapidity Dependence of Strangeness Production in Central Au+Au Collisions at RHIC

    E-Print Network [OSTI]

    Rapidity Dependence of Strangeness Production in Central Au+Au Collisions at RHIC D. Ouerdanea for the BRAHMS Collaboration a Niels Bohr Institute, University of Copenhagen, Denmark Abstract. We have measured measurement is used to complete and further discuss the energy and rapidity systematics of strangeness

  20. DESIGN STUDY OF THE DIPOLE MAGNET FOR THE RHIC EBIS HIGH ENERGY TRANSPORT LINE

    E-Print Network [OSTI]

    DESIGN The bending section in EBIS HEBT line consists of two identical H type magnets with a slit betweenDESIGN STUDY OF THE DIPOLE MAGNET FOR THE RHIC EBIS HIGH ENERGY TRANSPORT LINE Takeshi Kanesue magnet body should be laminated. In this paper, design methods of the dipole magnet to optimize magnetic

  1. PROCEEDINGS OF RIKEN BNL RESEARCH CENTER WORKSHOP ENTITLED "ODDERON SEARCHES AT RHIC" (VOLUME 76)

    SciTech Connect (OSTI)

    ORGANIZERS: GURYN, W.; KOVCHEGOV, Y.; VOGELSANG, W.; TRUEMAN, L.

    2005-10-25

    The Odderon, a charge-conjugation-odd partner of the Pomeron, has been a puzzle ever since its introduction in 1973. The Pomeron describes a colorless exchange with vacuum quantum numbers in the t-channel of hadronic scattering at high energies. The concept was originally formulated for the non-perturbative regime of Quantum Chromodynamics (QCD). In perturbation theory, the simplest picture of the Poineron is that of a two-gluon exchange process, whereas an Odderon can be thought of as an exchange of three gluons. Both the Pomeron and the Odderon are expected in QCD. However, while there exists plenty of experimental data that could be successfully described by Pomeron exchanges (for example in electron-proton and hadron-hadron scattering at high energies), no experimental sign of the Odderon has been observed. One of the very few hints so far is the difference in the diffractive minima of elastic proton-proton and proton-antiproton scattering measured at the ISR. The Odderon has recently received renewed attention by QCD researchers, mainly for the following two reasons. First of all, RHIC has entered the scene, offering exciting unique new opportunities for Odderon searches. RHIC provides collisions of nuclei at center-of-mass energies far exceeding those at all previous experiments. RHIC also provides collisions of protons of the highest center-of-mass energy, and in the interval, which has not been explored previously in p {bar p} collisions. In addition, it also has the unique feature of polarization for the proton beams, promising to become a crucial tool in Odderon searches. Indeed, theorists have proposed possible signatures of the Odderon in some spin asymmetries measurable at RHIC. Qualitatively unique signals should be seen in these observables if the Odderon coupling is large. Secondly, the Odderon has recently been shown to naturally emerge from the Color Glass Condensate (CGC), a theory for the high-energy asymptotics of QCD. It has been argued that saturation/CGC effects tend to decrease the Odderon intercept, possibly providing an explanation for the lack of experimental evidence for the Odderon so far. This has added further motivation for pursuing searches for the Odderon. During the workshop the status of the Odderon in QCD and its phenomenology were reviewed. The participants also agreed on the most promising observables for the Odderon search at RHIC, which we list. The conclusion of the workshop is that the best available setup to address experimental questions related to the search for the Odderon at RHIC is the proposed combination of STAR experiment and Roman pots of pp2pp experiment, described in the proposal ''Physics with Tagged Forward Protons with the STAR detector at RHIC''.

  2. Steffen A. Bass CTEQ 2004 Summer School #1 Dynamic Modeling of RHIC CollisionsDynamic Modeling of RHIC Collisions

    E-Print Network [OSTI]

    Bass, Steffen A.

    -ion collisions? · Introduction: the basics of kinetic theory · Examples of transport models and their application-equilibrium QGP and hydrodynamic expansion hadronization hadronic phase and freeze-out · rigorous calculation and data Transport-Theory: · only observe the final state · rely on QGP signatures predicted by Theory

  3. Partonic effects on the elliptic flow at relativistic heavy ion collisions 

    E-Print Network [OSTI]

    Lin, ZW; Ko, Che Ming.

    2002-01-01

    The elliptic flow in heavy ion collisions at the Relativistic Heavy Ion Collider is studied in a multiphase transport model. By converting the strings in the high energy density regions into partons, we find that the final elliptic flow is sensitive...

  4. Complementarity of the CERN Large Hadron Collider and the $e^+e^-$ International Linear Collider

    E-Print Network [OSTI]

    S. Y. Choi

    2008-09-10

    The next-generation high-energy facilities, the CERN Large Hadron Collider (LHC) and the prospective $e^+e^-$ International Linear Collider (ILC), are expected to unravel new structures of matter and forces from the electroweak scale to the TeV scale. In this report we review the complementary role of LHC and ILC in drawing a comprehensive and high-precision picture of the mechanism breaking the electroweak symmetries and generating mass, and the unification of forces in the frame of supersymmetry.

  5. SciDAC advances in beam dynamics simulation: from light sources to colliders

    E-Print Network [OSTI]

    Qiang, J.

    2008-01-01

    accelerator facilities, e.g. LCLS, RHIC, Tevatron, LHC,generation and transport in the LCLS photoinjector. Figure 2vertical offsets through the LCLS photoinjector. With such a

  6. SciDAC advances in beam dynamics simulation: from light sources to colliders

    E-Print Network [OSTI]

    Qiang, Ji

    2009-01-01

    accelerator facilities, e.g. LCLS, RHIC, Tevatron, LHC,generation and transport in the LCLS photoinjector. Figure 2vertical offsets through the LCLS photoinjector. With such a

  7. Photoproduction in Ultra-Peripheral Heavy-Ion Collisions

    E-Print Network [OSTI]

    Joakim Nystrand

    2008-02-13

    The strong electromagnetic fields present in ultra-peripheral collisions of heavy-ions offer a possibility to study two-photon and photonuclear collisions complementary to similar studies with lepton beams but over an increased photon energy range. This presentation will give an overview of photoproduction at hadron colliders.

  8. B Physics Theory for Hadron Colliders

    E-Print Network [OSTI]

    G. Buchalla

    2008-09-03

    A short overview of theoretical methods for B physics at hadron colliders is presented. The main emphasis is on the theory of two-body hadronic B decays, which provide a rich field of investigation in particular for the Tevatron and the LHC. The subject holds both interesting theoretical challenges as well as many opportunities for flavor studies and new physics tests. A brief review of the current status and recent developments is given. A few additional topics in B physics are also mentioned.

  9. Physics at the $e^+ e^-$ Linear Collider

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Moortgat-Picka, G.; Kronfeld, A. S.

    2015-08-14

    A comprehensive review of physics at an e+e? linear collider in the energy range of s?=92 GeV–3 TeV is presented in view of recent and expected LHC results, experiments from low-energy as well as astroparticle physics. The report focusses in particular on Higgs-boson, top-quark and electroweak precision physics, but also discusses several models of beyond the standard model physics such as supersymmetry, little Higgs models and extra gauge bosons. The connection to cosmology has been analysed as well.

  10. LHC - Large Hadon Collider Exhibition LEPFest 2000

    E-Print Network [OSTI]

    2000-01-01

    The Large Hadron Collider (LHC) will accelerate two proton beams to an energy corresponding to about 7,000 times their mass (7000 GeV). The collision of the two beams reproduces the conditions in the Universe when it was about 10 -1 2 sec old. Many innovative techniques - such as cooling with superfluid helium, the extensive use of high temperature superconducting cables, the two-in-one design for super-conducting dipole magnets, and new ultra-high vacuum technologies - had to be developed to make its construc-tion possible.

  11. Physics at the International Linear Collider

    E-Print Network [OSTI]

    J. List

    2006-05-18

    The International Linear Collider (ILC) is the next large project in accelerator based particle physics. It is complementary to the LHC in many aspects. Measurements from both machines together will finally shed light onto the known deficiencies of the Standard Model of particle physics and allow to unveil a possible underlying more fundamental theory. Here, the possibilities of the ILC will be discussed with special emphasis on the Higgs sector and on topics with a strong connection to cosmological questions like extra dimensions or dark matter candidates.

  12. Positron Polarization at the International Linear Collider

    E-Print Network [OSTI]

    P. Osland; N. Paver

    2005-07-15

    We review some recent arguments supporting the upgrade of the International Linear Collider by a polarized positron beam, in addition to the polarized electron beam. The examples presented here mainly focus on the impact of positron polarization on items relevant to new physics searches, such as the identification of novel interactions in fermion-pair production and the formulation of new CP-sensitive observables. In particular, in addition to the benefits from positron and electron longitudinal polarizations, the advantages in this field of having transverse polarization of both beams are emphasized.

  13. HEP Collider HPC Use, Prospects and Wishes

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would likeUniverse (Journalvivo Low-Dose Lowï‚— WeUpdateScience DeadlinesHEP Collider HPC

  14. Michael Schmitt Physics at a -Collider 20-March-2001 1 Physics at a -Collider

    E-Print Network [OSTI]

    Schmitt, Michael

    . emphasizes diboson over difermion production { in contrast to e + e machines. #15; Pair-production of charged of speci#12;c CP #15; Since photons couple only to electric charge, production of neutral particles to be tied to the data { not unlike hadronic machines. #12; Michael Schmitt Physics at a -Collider 20-March

  15. Low-mass dielectrons from the PHENIX experiment at RHIC

    E-Print Network [OSTI]

    Alexander Kozlov

    2006-11-14

    The production of the low-mass dielectrons is considered to be a powerful tool to study the properties of the hot and dense matter created in the ultra-relativistic heavy-ion collisions. We present the preliminary results on the first measurements of the low-mass dielectron continuum in Au+Au collisions and the phi meson production measured in Au+Au and d+Au collisions at sqrt{s_NN} = 200 GeV performed by the PHENIX experiment.

  16. LASER-PLASMA-ACCELERATOR-BASED GAMMA GAMMA COLLIDERS

    E-Print Network [OSTI]

    Schroeder, C. B.

    2010-01-01

    LASER-PLASMA-ACCELERATOR-BASED ?? COLLIDERS ? C. B.linear col- lider based on laser-plasma-accelerators arediscussed, and a laser-plasma-accelerator-based gamma-

  17. A young person's view of the Superconducting Super Collider

    SciTech Connect (OSTI)

    Moya, A.

    1990-08-01

    This report gives a simple description of the Superconducting Super Collider, how it works, and what it is used for. (LSP)

  18. Far Future Colliders and Required R&D Program

    SciTech Connect (OSTI)

    Shiltsev, V.; /Fermilab

    2012-06-01

    Particle colliders for high energy physics have been in the forefront of scientific discoveries for more than half a century. The accelerator technology of the collider has progressed immensely, while the beam energy, luminosity, facility size and the cost have grown by several orders of magnitude. The method of colliding beams has not fully exhausted its potential but its pace of progress has greatly slowed down. In this paper we very briefly review the R&D toward near future colliders and make an attempt to look beyond the current horizon and outline the changes in the paradigm required for the next breakthroughs.

  19. Klystron switching power supplies for the Internation Linear Collider

    SciTech Connect (OSTI)

    Fraioli, Andrea; /Cassino U. /INFN, Pisa

    2009-12-01

    The International Linear Collider is a majestic High Energy Physics particle accelerator that will give physicists a new cosmic doorway to explore energy regimes beyond the reach of today's accelerators. ILC will complement the Large Hadron Collider (LHC), a proton-proton collider at the European Center for Nuclear Research (CERN) in Geneva, Switzerland, by producing electron-positron collisions at center of mass energy of about 500 GeV. In particular, the subject of this dissertation is the R&D for a solid state Marx Modulator and relative switching power supply for the International Linear Collider Main LINAC Radio Frequency stations.

  20. EBIS PREINJECTOR CONSTRUCTION STATUS* , D. Barton, E. Beebe, S. Bellavia, O. Gould, A. Kponou, R. Lambiase, E. Lessard,

    E-Print Network [OSTI]

    Abstract A new heavy ion preinjector is presently under construction at Brookhaven National Laboratory the preinjector to the heavy ion injection point of the Booster Synchrotron. This preinjector will replace two for both the Relativistic Heavy Ion Collider (RHIC) and NASA Space Radiation Laboratory (NSRL

  1. Precision Polarimetry at the International Linear Collider

    E-Print Network [OSTI]

    C. Helebrant; D. Käfer; J. List

    2008-10-13

    The International Linear Collider (ILC) will collide polarised electrons and positrons at beam energies of 45.6 GeV to 250 GeV and optionally up to 500 GeV. To fully exploit the physics potential of this machine, not only the luminosity and beam energy have to be known precisely, but also the polarisation of the particles has to be measured with an unprecedented precision of dP/P ~ 0.25% for both beams. An overall concept of high precision polarisation measurements at high beam energies will be presented. The focus will be on the polarimeters (up- and downstream of the e+e- interaction point) embedded in the ILC beam delivery system. Some challenges concerning the design of the Compton spectrometers and the appropriate Cherenkov detectors for each polarimeter are discussed. Detailed studies of photodetectors and their readout electronics are presented focusing specifically on the linearity of the device, since this is expected to be the limiting factor on the precision of the polarisation measurement at the ILC.

  2. Systematic Studies of Jet Quenching in Hot Nuclear Matter 

    E-Print Network [OSTI]

    Delgado, Andrea

    2011-05-04

    at machines like the Relativistic Heavy Ion Collider (RHIC) and the Large Hadron Collider (LHC) we can create and investigate tiny bubbles of Quark Gluon Plasma for very short periods of time before they cool and decay. We can use so-called QCD jets i...

  3. Probing properties of hot and dense QCD matter with heavy flavor in the PHENIX experiment at RHIC

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Nouicer, Rachid

    2015-05-29

    Hadrons carrying heavy quarks, i.e. charm or bottom, are important probes of the hot and dense medium created in relativistic heavy ion collisions. Heavy quark-antiquark pairs are mainly produced in initial hard scattering processes of partons. While some of the produced pairs form bound quarkonia, the vast majority hadronize into particles carrying open heavy flavor. Heavy quark production has been studied by the PHENIX experiment at RHIC via measurements of single leptons from semi-leptonic decays in both the electron channel at mid-rapidity and in the muon channel at forward rapidity. A large suppression and azimuthal anisotropy of single electrons havemore »been observed in Au + Au collisions at 200 GeV. These results suggest a large energy loss and flow of heavy quarks in the hot, dense matter. The PHENIX experiment has also measured J/? production at 200 GeV in p + p, d + Au, Cu + Cu and Au + Au collisions, both at mid- and forward-rapidities, and additionally Cu + Au and U + U at forward-rapidities. In the most energetic collisions, more suppression is observed at forward rapidity than at central rapidity. This can be interpreted either as a sign of quark recombination, or as a hint of additional cold nuclear matter effects. The centrality dependence of nuclear modification factor, RAA(pT), for J/? in U + U collisions at ?sNN = 193 GeV shows a similar trend to the lighter systems, Au + Au and Cu + Cu, at similar energy 200 GeV.« less

  4. A Proposal for the Muon Piston Calorimeter Extension (MPC-EX) to the PHENIX Experiment at RHIC

    E-Print Network [OSTI]

    S. Campbell; R. Hollis; A. Iordanova; E. Kistenev; X. Jiang; Y. Kwon; J. Lajoie; J. Perry; R. Seto; A. Sukhanov; A. Timilsina; for the PHENIX Collaboration

    2013-01-07

    The PHENIX MPC-EX detector is a Si-W preshower extension to the existing PHENIX Muon Piston Calorimeters (MPC). The MPC-EX will consist of eight layers of alternating W absorber and Si mini-pad sensors and will be installed in time for RHIC Run-15. Covering a large pseudorapidity range, 3.1 energies > 80 GeV, a factor of four improvement over current capabilities. Not only will the MPC-EX strengthen PHENIX's existing forward neutral pion and jet measurements, it also provides the necessary neutral pion rejection to make a prompt photon measurement feasible in both p+A and p+p collisions. With this neutral pion rejection, prompt (direct + fragmentation) photon yields at high p_T, p_T > 3 GeV, can be statistically extracted using a double ratio method. In p+A collisions direct photons at forward rapidities are optimally sensitive to the gluon distribution because, unlike pions, direct photons are only produced by processes that are directly sensitive to the gluon distribution at leading order. A measurement of the forward prompt photon R_pA will cleanly access and greatly expand our understanding of the gluon nuclear parton distribution functions and provide important information about the initial state in heavy ion collisions. In transversely polarized p+p collisions the MPC-EX will make possible a measurement of the prompt photon single spin asymmetry A_N, and will help elucidate the correlation of valence partons in the proton with the proton spin.

  5. A feasibility experiment at RHIC to measure the analyzing power for Drell-Yan production (ANDY)

    E-Print Network [OSTI]

    L. Nogach; for the ANDY collaboration

    2011-12-08

    Large transverse single spin asymmetries (SSA) were measured for pions produced in pp-collisions up to RHIC energies. Sizeable SSA were also found in semi-inclusive deep inelastic scattering (SIDIS). Theory can explain such spin effects by going beyond collinear leading-twist perturbative QCD (pQCD) to include transverse momentum dependent (TMD) distribution and fragmentation functions. One of the most interesting TMDs is the Sivers function, which provides information on the correlation between the transverse spin of the nucleon and the transverse momentum distributions of the partons in the nucleon. It is particularly intriguing that theory predicts the Sivers function will change sign from SIDIS to Drell-Yan (DY) production. ANDY is aiming to test that prediction and to establish requirements for future upgrades at RHIC to study DY production. The experiment configuration, achievements to date, status and plans are discussed.

  6. A feasibility experiment at RHIC to measure the analyzing power for Drell-Yan production (ANDY)

    E-Print Network [OSTI]

    Nogach, L

    2011-01-01

    Large transverse single spin asymmetries (SSA) were measured for pions produced in pp-collisions up to RHIC energies. Sizeable SSA were also found in semi-inclusive deep inelastic scattering (SIDIS). Theory can explain such spin effects by going beyond collinear leading-twist perturbative QCD (pQCD) to include transverse momentum dependent (TMD) distribution and fragmentation functions. One of the most interesting TMDs is the Sivers function, which provides information on the correlation between the transverse spin of the nucleon and the transverse momentum distributions of the partons in the nucleon. It is particularly intriguing that theory predicts the Sivers function will change sign from SIDIS to Drell-Yan (DY) production. ANDY is aiming to test that prediction and to establish requirements for future upgrades at RHIC to study DY production. The experiment configuration, achievements to date, status and plans are discussed.

  7. Obtaining the Specific Heat of Hadronic Matter from CERN/RHIC Experiments

    E-Print Network [OSTI]

    Aram Mekjian

    2005-03-03

    The specific heat of hot hadronic matter is related to particle production yields from experiments done at CERN/RHIC. The mass fluctuation of excited hadrons plays an important role. Connections of the specific heat, mean hadronic mass excited and its fluctuation with properties of baryon and electric chemical potentials (value, slope and curvature) are also developed. A possible divergence of the specific heat as 1/(To-T)^2 is discussed. Some connections with net charge fluctuations are noted.

  8. RHIC 12x150A current lead temperature controller: design and implementation

    SciTech Connect (OSTI)

    Mi, C.; Seberg, S.; Ganetis, Hamdi, K.; Louie, W.; Heppner, G.; Jamilkowski, J.; Bruno, D.; DiLieto, A.; Sirio, C.; Tuozzolo, J.; Sandberg, J.; Unger, K.

    2011-03-28

    There are 60 12 x 150A current leads distributed in six RHIC service buildings; each lead delivers power supply current from room temperature to cryogenic temperature in RHIC. Due to the humid environment, condensation occurs frequently and ice forms quickly during operation, especially during an extensive storage period. These conditions generate warnings and alarms to which personnel must respond and establish temporary solutions to keep the machine operating. In here, we designed a temperature control system to avoid such situations. This paper discusses its design, implementation, and some results. There are six service buildings in the RHIC complex; each building has two valve boxes that transfer room-temperature current cables from the power supplies into superconducting leads, and then transport them into the RHIC tunnel. In there, the transition between the room-temperature lead into superconducting lead is critical and essential; smooth running during the physics store is crucial for the machine's continuing operation. One of the problems that often occurred previously was the icing of these current leads that could result in a potential leakage current onto ground, thereby preventing a continuous supply of physics store. Fig. 1 illustrates a typical example on a power lead. Among the modifications of the design of the valve box, we list below the new requirements for designing the temperature controller to prevent icing occurring: (1) Remotely control, monitor, and record each current lead's temperature in real time. Prevent icing or overheating of a power lead. (2) Include a temperature alarm for the high/low level threshold. In this paper we discuss the design, implementation, upgrades to, and operation of this new system.

  9. Extraction and transformation of proton beam at RHIC using bent crystals

    SciTech Connect (OSTI)

    Nurushev, S.B.; Krivosheev, O.E.; Pivovarov, Y.L.; Potylitsin, A.P.

    1995-09-01

    The effect of transformation of polarization of relativistic protons using extraction and deflection by bent crystal is investigated by means of computer simulation. The 250 {ital GeV}/{ital c} proton beam from RHIC can be deflected to an angle, {theta}{sub {ital p}}=3 mrad with simultaneous transformation of initial longitudinal polarization to transverse polarization. {copyright} {ital 1995 American Institute of Physics.}

  10. Strange particles production in relativistic nucleus-nucleus collisions at the RHIC BES energy region

    E-Print Network [OSTI]

    Zhang, Cong-Cong; Feng, Sheng-Qin; Yin, Zhong-Bao

    2015-01-01

    The parton and hadron cascade model PACIAE is utilized to investigate strange particle productions in Au + Au collision at $\\sqrt{s}$=62.4 GeV in different centralities and at $\\sqrt{s}$= 39, 11.5 and 7.7 GeV in the most central collision, respectively. It is shown that the transverse momentum distributions of strange particles by the PACIAE model fit well the RHIC BES experimental results.

  11. Spin effects in diffractive $ Q \\bar Q$ production at BNL eRHIC

    E-Print Network [OSTI]

    S. V. Goloskokov

    2004-06-16

    We discuss quark-antiquark leptoproduction within a QCD two-gluon exchange model at small $x$. The double spin asymmetries for longitudinally polarized leptons and transversely polarized protons in diffractive $Q \\bar Q$ production are analysed at eRHIC energies. The predicted $A_{lT}$ asymmetry is large and can be used to obtain information on the polarized generalized gluon distributions in the proton.

  12. Spin effects in diffractive $ Q \\bar Q$ production at eRHIC

    E-Print Network [OSTI]

    Goloskokov, S V

    2004-01-01

    We discuss quark-antiquark leptoproduction within a QCD two-gluon exchange model at small $x$. The double spin asymmetries for longitudinally polarized leptons and transversely polarized protons in diffractive $Q \\bar Q$ production are analysed at eRHIC energies. The predicted $A_{lT}$ asymmetry is large and can be used to obtain information on the polarized generalized gluon distributions in the proton.

  13. J/Psi and Psi' Polarizations in Polarized Proton-Proton Collisions at the RHIC

    E-Print Network [OSTI]

    Gouranga C. Nayak; J. Smith

    2005-12-07

    We study inclusive heavy quarkonium production with definite polarizations in polarized proton-proton collisions using the non-relativistic QCD color-octet mechanism. We present results for rapidity distributions of cross sections and spin asymmetries for the production of J/psi and psi' with specific polarizations in polarized p-p collisions at \\sqrt s = 200 GeV and 500 GeV at the RHIC within the PHENIX detector acceptance range.

  14. Alternative Contributions to the Angular Correlations Observed at RHIC Associated with Parity Fluctuations

    E-Print Network [OSTI]

    Scott Pratt

    2010-02-09

    Recent measurements at RHIC of angular correlations of same-sign vs. opposite sign pairs have been interpreted as evidence for large-scale fluctuations of parity-odd fields. In this paper, we provide alternative explanations of the same phenomena based on correlations from charge and momentum conservation overlaid with elliptic flow. These effects are shown to produce correlations with similar magnitudes as those measured. Other correlations are also considered, but estimates of their size suggest they are inconsequential.

  15. Buda-Lund hydro model and the elliptic flow at RHIC

    E-Print Network [OSTI]

    M. Csanad; T. Csorgo; B. Lorstad

    2004-02-12

    The ellipsoidally symmetric Buda-Lund hydrodynamic model describes naturally the transverse momentum and the pseudorapidity dependence of the elliptic flow in Au+Au collisions at $\\sqrt{s_{NN}} = 130$ and 200 GeV. The result confirms the indication of quark deconfinement in Au+Au collisions at RHIC, obtained from Buda-Lund hydro model fits to combined spectra and HBT radii of BRAHMS, PHOBOS, PHENIX and STAR.

  16. Experience with low-energy gold-gold operations in RHIC during FY 2010

    SciTech Connect (OSTI)

    Montag, C.; Satogata, T.; Ahrens, L.A.; Bai, M.; Beebe-Wang, J.; Blacker, I.; et al

    2011-10-07

    During Run-10, RHIC operated at several different Au-Au collision energies, as requested mainly by the STAR collaboration in a quest to search for the critical point in the QGP phase diagram. The center-of-mass energies {radical}s{sub NN} are listed in Table 1, together with the respective start and end dates and the duration of the respective run at each energy. While STAR defines 'low energy' as anything below {radical}s{sub NN} = 39 GeV, we focus in the scope of this paper on energies below the regular RHIC injection energy of {radical}s{sub NN} {approx} 20 GeV, since this energy regime is particularly challenging for stable RHIC operations. Figures 1 and 2 show the evolution of beam intensity and luminosity during the course of the {radical}s{sub NN} = 7.7 GeV and 11.5 GeV run. In the following sections we will recapitulate the modifications during the run that led to significant performance improvements, and summarize what was learned at the various energies for possible application in future runs.

  17. A Complete Onium Program with R2D at RHIC II

    E-Print Network [OSTI]

    Richard Witt

    2006-05-16

    Following on the discovery of a strongly interacting quark-gluon plasma (QGP) at RHIC, a program of detailed quarkonia measurements is crucial to understanding the nature of deconfinement. Lattice QCD calculations suggest a sequential melting of the quarkonia states in the deconfined medium. Such a melting would lead to a suppression in the measured charmonium and bottomonium yields. However, distinguishing a true suppression from shadowing, absorption, and recombination effects requires detailed measurements of the charmonium states (J/psi, psi', and chi_c) and bottomonium states (Y(1S), Y(2S), and Y(3S)). Also, since measurements are needed not only in A+A, but also in p+p for determining primary yields and in p+A for evaluating absorption, the detector should perform well in all collision environments. To fully realize the program outlined above, a new detector will be required at RHIC-II. We present a proposal for a complete quarkonia program and the abilities of a new detector, R2D, to meet the stated requirements. Comparisons will be made with proposed upgrades to existing RHIC detectors and with the upcoming LHC program.

  18. Interactions of $B_{c}$ Meson in Relativistic Heavy-Ion Collisions

    E-Print Network [OSTI]

    Irfan, Shaheen; Masud, Bilal

    2015-01-01

    We calculate the absorbtion cross-sections of $B_{c}$ mesons by $\\pi$ and $\\rho$ mesons including anomalous processes using an effective hadronic Lagrangian. The enhancement of Bc production is expected due to QGP formation in heavy-ion experiments. However it is also expected that the production rate of Bc meson can be affected due to the interaction with comovers. These processes are relevant for experiments at RHIC. Thermal average cross-sections of $B_{c}$ are evaluated with form factor when a cut off parameter in it is 1 and 2 GeV. Using these thermal average cross-sections in the kinetic equation we investigate the time evolution of $B_{c}$ mesons due to dissociation in the hadronic matter formed at RHIC.

  19. Colliding Laser Pulses for Laser-Plasma Accelerator Injection Control

    E-Print Network [OSTI]

    Geddes, Cameron Guy Robinson

    Colliding Laser Pulses for Laser-Plasma Accelerator Injection Control G. R. Plateau, , C. G. R acceleration is a key challenge to achieve compact, reliable, tunable laser-plasma accelerators (LPA) [1, 2]. In colliding pulse injection the beat between multiple laser pulses can be used to control energy, energy

  20. VEPP-2000 COLLIDER CONTROL SYSTEM* A.Senchenko1,#

    E-Print Network [OSTI]

    Kozak, Victor R.

    VEPP-2000 COLLIDER CONTROL SYSTEM* A.Senchenko1,# , D.Berkaev1,2 , O.Gorbatenko1 , A.Kasaev1 , I of interacting subsystems responding on different acceleration facility parts. Control system software is based presents architecture, implementation and functionality of hardware and software of the collider control

  1. The Neutrino Factory and Muon Collider Collaboration Considerations on

    E-Print Network [OSTI]

    McDonald, Kirk

    Plenary Meeting, KEK Jan 24, 2006 http://puhep1.princeton.edu/mumu/target/ (Presented by M. Zisman) Kirk T.) Kirk T. McDonald ISS Plenary Meeting, KEK, Jan 24, 2006 2 #12;The Neutrino Factory and Muon Collider". Kirk T. McDonald ISS Plenary Meeting, KEK, Jan 24, 2006 3 #12;The Neutrino Factory and Muon Collider

  2. Helmholtz Alliance Linear Collider Forum Proceedings of the Workshops

    E-Print Network [OSTI]

    Helmholtz Alliance Linear Collider Forum Proceedings of the Workshops Hamburg, Munich, Hamburg 2010 of the Helmholtz Alliance Linear Collider Forum 2010­2012, Hamburg, M¨unchen, Hamburg, Germany Conference homepage, Internationales Congress Center, Dresden (at the 4th Annual Workshop of the Helmholtz Alliance `Physics

  3. CLIC Drive Beam and LHC Based Fel-Nucleus Collider

    E-Print Network [OSTI]

    H. Braun; R. Corsini; S. Sultansoy; O. Yavas

    2005-08-09

    The feasibility of a CLIC-LHC based FEL-nucleus collider is investigated. It is shown that the proposed scheme satisfies all requirements of an ideal photon source for the Nuclear Resonance Fluorescence method. The physics potential of the proposed collider is illustrated for a beam of Pb nuclei.

  4. CONTROL SYSTEM OF VEPP-2000 COLLIDER (SOFTWARE, HARDWARE)

    E-Print Network [OSTI]

    Kozak, Victor R.

    CONTROL SYSTEM OF VEPP-2000 COLLIDER (SOFTWARE, HARDWARE) D.E.Berkaev, P.B.Cheblakov, V, implementation and functionality of the software of the collider control system. The software according. Control system software is based on several TCP/IP connected PC platforms working under operating system

  5. The Higgs Physics Programme at the International Linear Collider

    E-Print Network [OSTI]

    Felix Sefkow

    2014-10-13

    The talk summarises the case for Higgs physics in $e^+e^-$ collisions and explains how Higgs parameters can be extracted in a model-independent way at the International Linear Collider (ILC). The expected precision will be discussed in the context of projections for the experiments at the Large Hadron Collider (LHC).

  6. The Higgs Physics Programme at the International Linear Collider

    E-Print Network [OSTI]

    Sefkow, Felix

    2014-01-01

    The talk summarises the case for Higgs physics in $e^+e^-$ collisions and explains how Higgs parameters can be extracted in a model-independent way at the International Linear Collider (ILC). The expected precision will be discussed in the context of projections for the experiments at the Large Hadron Collider (LHC).

  7. Energy Content of Colliding Plane Waves using Approximate Noether Symmetries

    E-Print Network [OSTI]

    M. Sharif; Saira Waheed

    2011-09-19

    This paper is devoted to study the energy content of colliding plane waves using approximate Noether symmetries. For this purpose, we use approximate Lie symmetry method of Lagrangian for differential equations. We formulate the first-order perturbed Lagrangian for colliding plane electromagnetic and gravitational waves. It is shown that in both cases, there does not exist

  8. EIS-0138-S: Superconducting Super Collider, Supplemental, Waxahatchie, Texas

    Broader source: Energy.gov [DOE]

    The U.S. Department of Energy developed this supplementary statement to analyze the environmental impacts of design modifications to the Superconducting Super Collider that were made following the publication of the Record of Decision that selected Ellis County, Texas, as the location of the laboratory facility. This statement supplements DOE/EIS-0138, Superconducting Super Collider.

  9. PION PRODUCTION FOR NEUTRINO FACTORIES AND MUON COLLIDERS

    E-Print Network [OSTI]

    McDonald, Kirk

    PION PRODUCTION FOR NEUTRINO FACTORIES AND MUON COLLIDERS Workshop on Applications of High production for nufact/mu-collider - N.V. Mokhov Outline · Pion Production and Collection · Event Generators-independent analysis of HARP data 2 #12;AHIPA Workshop, Fermilab, October 19-21, 2009 Pion production for nufact

  10. News from CERN, LHC Status and Strategy for Linear Colliders

    E-Print Network [OSTI]

    Rolf-Dieter Heuer

    2012-02-27

    This paper presents the latest development at CERN, concentrating on the status of the LHC and the strategy for future linear colliders. The immediate plans include the exploitation of the LHC at its design luminosity and energy as well as upgrades to the LHC (luminosity and energy) and to its injectors. This may be complemented by a linear electron-positron collider, based on the technology being developed by the Compact Linear Collider and by the International Linear Collider and/or by a high-energy electron-proton collider. This contribution describes the various future directions, all of which have a unique value to add to experimental particle physics, and concludes by outlining key messages for the way forward.

  11. Fragmentation of colliding planetesimals with water content

    E-Print Network [OSTI]

    Maindl, Thomas I; Schäfer, Christoph; Speith, Roland

    2014-01-01

    We investigate the outcome of collisions of Ceres-sized planetesimals composed of a rocky core and a shell of water ice. These collisions are not only relevant for explaining the formation of planetary embryos in early planetary systems, but also provide insight into the formation of asteroid families and possible water transport via colliding small bodies. Earlier studies show characteristic collision velocities exceeding the bodies' mutual escape velocity which - along with the distribution of the impact angles - cover the collision outcome regimes 'partial accretion', 'erosion', and 'hit-and-run' leading to different expected fragmentation scenarios. Existing collision simulations use bodies composed of strengthless material; we study the distribution of fragments and their water contents considering the full elasto-plastic continuum mechanics equations also including brittle failure and fragmentation.

  12. Another Detector for the International Linear Collider

    E-Print Network [OSTI]

    Nural Akchurin; Sehwook Lee; Richard Wigmans; Hanna Arnold; Aaron Bazal; Robert Basili; John Hauptman; Tim Overton; Andrew Priest; Bingzhe Zhao; Alexander Mikhailichenko; Michele Cascella; Franco Grancagnolo; Giovanni Tassielli; Franco Bedeschi; Fabrizio Scuri; Sung Keun Park; Fedor Ignatov; Gabriella Gaudio; Michele Livan

    2013-07-25

    We describe another detectora designed for the International Linear Collider based on several tested instrumentation innovations in order to achieve the necessary experi- mental goal of a detecter that is 2-to-10 times better than the already excellent SLC and LEP detectors, in particular, (1) dual-readout calorimeter system based on the RD52/DREAM measurements at CERN, (2) a cluster-counting drift chamber based on the successful kloe chamber at Frascati, and (3) a second solenoid to return the magnetic flux without iron. A high-performance pixel vertex chamber is presently undefined. We discuss particle identification, momentum and energy resolutions, and the machine-detector interface that together offer the possibility of a very high-performance detector for $e^+e^-$physics up to $\\sqrt{s} = 1$ TeV.

  13. Detectors for Linear Colliders: Calorimetry at a Future Electron-Positron Collider (3/4)

    ScienceCinema (OSTI)

    None

    2011-10-06

    Calorimetry will play a central role in determining the physics reach at a future e+e- collider. The requirements for calorimetry place the emphasis on achieving an excellent jet energy resolution. The currently favoured option for calorimetry at a future e+e- collider is the concept of high granularity particle flow calorimetry. Here granularity and a high pattern recognition capability is more important than the single particle calorimetric response. In this lecture I will describe the recent progress in understanding the reach of high granularity particle flow calorimetry and the related R&D; efforts which concentrate on test beam demonstrations of the technological options for highly granular calorimeters. I will also discuss alternatives to particle flow, for example the technique of dual readout calorimetry.

  14. Collider Phenomenology with Split-UED

    SciTech Connect (OSTI)

    Kong, Kyoungchul; /SLAC; Park, Seong Chan; /Tokyo U., IPMU; Rizzo, Thomas G.; /SLAC

    2011-12-15

    We investigate the collider implications of Split Universal Extra Dimensions. The non-vanishing fermion mass in the bulk, which is consistent with the KK-parity, largely modifies the phenomenology of Minimal Universal Extra Dimensions. We scrutinize the behavior of couplings and study the discovery reach of the Tevatron and the LHC for level-2 Kaluza-Klein modes in the dilepton channel, which would indicates the presence of the extra dimensions. Observation of large event rates for dilepton resonances can result from a nontrivial fermion mass profile along the extra dimensions, which, in turn, may corroborate extra dimensional explanation for the observation of the positron excess in cosmic rays. The Minimal Universal Extra Dimensions scenario has received great attention. Recently non-vanishing bulk fermion masses have been introduced without spoiling the virtue of KK-parity. The fermion profiles are no longer simple sine/cosine functions and depend upon the specific values of bulk parameters. The profiles of fermions are split along the extra dimensions while the wave functions of the bosons remain the same as in UED. A simple introduction of a KK-parity conserving bulk fermion mass has significant influences on collider aspects as well as astrophysical implications of UED. For instance, the DM annihilation fraction into certain SM fermion pairs is either enhanced or reduced (compared to the MUED case) so that one can perhaps explain the PAMELA positron excess while suppressing the anti-proton flux. In this paper, we have concentrated on collider phenomenology of Split Universal Extra Dimensions. We have revisited the KK decomposition in detail and analyzed wave function overlaps to compute relevant couplings for collider studies. We have discussed general collider implication for level-1 KK modes and level-2 KK with non-zero bulk mass and have computed LHC reach for the EW level-2 KK bosons, {gamma}{sub 2} and Z{sub 2}, in the dilepton channel. The LHC should able to cover the large parameter space (up to M{sub V{sub 2}} {approx} 1.5 TeV for {mu}L {ge} 1) even with early data assuming {approx}100 pb{sup -1} or less. The existence of double resonances is one essential feature arising from extra dimensional models. Whether or not one can see double resonances depends both on how degenerate the two resonances are and on the mass resolution of the detector. The very high P{sub T} from the decay makes resolution in dimuon channel worse than in dielectron final state. This is because one can reconstruct electron from ECAL but muon momentum reconstruction relies on its track, which is barely curved in this case. Further indication for SUED might be the discovery of W'-like signature of mass close to Z{sub 2}. The MUED predicts a somewhat lower event rate due to 1-loop suppressed coupling of level-2 bosons to SM fermion pair, while it exists at tree level in SUED. Therefore in UED, one has to rely on indirect production of level-2 bosons, whose collider study requires complete knowledge of the model: the mass spectrum and all the couplings. On the other hand, in the large {mu} limit of SUED, the dependence on mass spectrum is diminished since level-2 KK bosons decay only into SM fermion pairs. This allows us to estimate the signal rate from their direct production, so that they can be discovered at the early phase of the LHC. The indirect production mechanism only increases production cross sections, improving our results. Once a discovery has been made, one should try to reconstruct events and do further measurements such as spin and coupling determination, with more accumulated data, which might discriminate KK resonances from other Z' models. The coupling measurement is directly related to the determination of the bulk masses. A challenging issue might be the existence of two resonances which are rather close to each other.

  15. Universal Behavior of Charged Particle Production in Heavy Ion Collisions

    E-Print Network [OSTI]

    Peter Steinberg; PHOBOS Collaboration

    2002-11-01

    The PHOBOS experiment at RHIC has measured the multiplicity of primary charged particles as a function of centrality and pseudorapidity in Au+Au collisions at sqrt(s_NN) = 19.6, 130 and 200 GeV. Two kinds of universal behavior are observed in charged particle production in heavy ion collisions. The first is that forward particle production, over a range of energies, follows a universal limiting curve with a non-trivial centrality dependence. The second arises from comparisons with pp/pbar-p and e+e- data. N_tot/(N_part/2) in nuclear collisions at high energy scales with sqrt(s) in a similar way as N_tot in e+e- collisions and has a very weak centrality dependence. This feature may be related to a reduction in the leading particle effect due to the multiple collisions suffered per participant in heavy ion collisions.

  16. Partonic effects on higher-order anisotropic flows in relativistic heavy-ion collisions RID A-2398-2009 

    E-Print Network [OSTI]

    Chen, LW; Ko, Che Ming; Lin, ZW.

    2004-01-01

    Higher-order anisotropic flows v(4) and v(6) of charged hadrons in heavy-ion collisions at the Relativistic Heavy Ion Collider are studied in a multiphase transport model that has previously been used successfully for describing the elliptic flow v...

  17. Forschung fr den International Linear Collider Abbildung 55: Simuliertes Ereignis im Kalorimeter Prototypen fr den ILC. Drei Detektoren

    E-Print Network [OSTI]

    Forschung für den International Linear Collider Abbildung 55: Simuliertes Ereignis im Kalorimeter #12;Forschung für den International Linear Collider Forschung für den International Linear Collider Treffen der Maschinenexperten, eindrucks- voll demonstriert. Der Name ,,International Linear Collider

  18. Single-Bunch Instability Driven by the Electron Cloud Effect in the Positron Damping Ring of the International Linear Collider

    E-Print Network [OSTI]

    2005-01-01

    RING OF THE INTERNATIONAL LINEAR COLLIDER* M. Pivi # , T.DR) of the International Linear Collider (ILC), an electron

  19. TOP AND HIGGS PHYSICS AT THE HADRON COLLIDERS

    SciTech Connect (OSTI)

    Jabeen, Shabnam

    2013-10-20

    This review summarizes the recent results for top quark and Higgs boson measurements from experiments at Tevatron, a proton–antiproton collider at a center-of-mass energy of ? s =1 . 96 TeV, and the Large Hadron Collider, a proton–proton collider at a center- of-mass energy of ? s = 7 TeV. These results include the discovery of a Higgs-like boson and measurement of its various properties, and measurements in the top quark sector, e.g. top quark mass, spin, charge asymmetry and production of single top quark.

  20. Laser cooling of electron beams for linear colliders

    E-Print Network [OSTI]

    Valery Telnov

    2013-10-24

    A novel method of electron beam cooling is considered which can be used for linear colliders. The electron beam is cooled during collision with focused powerful laser pulse. With reasonable laser parameters (laser flash energy about 10 J) one can decrease transverse beam emittances by a factor about 10 per one stage. The ultimate transverse emittances are much below those achievable by other methods. Beam depolarization during cooling is about 5--15 % for one stage. This method is especially useful for photon colliders and opens new possibilities for e+e- colliders.

  1. LCFIPlus: A Framework for Jet Analysis in Linear Collider Studies

    E-Print Network [OSTI]

    Taikan Suehara; Tomohiko Tanabe

    2015-06-28

    We report on the progress in flavor identification tools developed for a future $e^+e^-$ linear collider such as the International Linear Collider (ILC) and Compact Linear Collider (CLIC). Building on the work carried out by the LCFIVertex collaboration, we employ new strategies in vertex finding and jet finding, and introduce new discriminating variables for jet flavor identification. We present the performance of the new algorithms in the conditions simulated using a detector concept designed for the ILC. The algorithms have been successfully used in ILC physics simulation studies, such as those presented in the ILC Technical Design Report.

  2. LCFIPlus: A Framework for Jet Analysis in Linear Collider Studies

    E-Print Network [OSTI]

    Suehara, Taikan

    2015-01-01

    We report on the progress in flavor identification tools developed for a future $e^+e^-$ linear collider such as the International Linear Collider (ILC) and Compact Linear Collider (CLIC). Building on the work carried out by the LCFIVertex collaboration, we employ new strategies in vertex finding and jet finding, and introduce new discriminating variables for jet flavor identification. We present the performance of the new algorithms in the conditions simulated using a detector concept designed for the ILC. The algorithms have been successfully used in ILC physics simulation studies, such as those presented in the ILC Technical Design Report.

  3. New Methods of Particle Collimation in Colliders

    SciTech Connect (OSTI)

    Stancari, Giulio; /Fermilab

    2011-10-01

    The collimation system is an essential part of the design of any high-power accelerator. Its functions include protection of components from accidental and intentional energy deposition, reduction of backgrounds, and beam diagnostics. Conventional multi-stage systems based on scatterers and absorbers offer robust shielding and efficient collection of losses. Two complementary concepts have been proposed to address some of the limitations of conventional systems: channeling and volume reflection in bent crystals and collimation with hollow electron beams. The main focus of this paper is the hollow electron beam collimator, a novel concept based on the interaction of the circulating beam with a 5-keV, magnetically confined, pulsed hollow electron beam in a 2-m-long section of the ring. The electrons enclose the circulating beam, kicking halo particles transversely and leaving the beam core unperturbed. By acting as a tunable diffusion enhancer and not as a hard aperture limitation, the hollow electron beam collimator extends conventional collimation systems beyond the intensity limits imposed by tolerable losses. The concept was tested experimentally at the Fermilab Tevatron proton-antiproton collider. Results on the collimation of 980-GeV antiprotons are presented, together with prospects for the future.

  4. The Next Linear Collider Klystron Development Program*

    E-Print Network [OSTI]

    E. Jongewaard; G. Caryotakis; C. Pearson; R. M. Phillips; D. Sprehn; A. Vlieks

    2000-08-19

    Klystrons capable of 75 MW output power at 11.4 GHz have been under development at SLAC for the last decade. The work has been part of the program to realize all the components necessary for the construction of the Next Linear Collider (NLC). The effort has produced a family of solenoid-focused 50 MW klystrons, which are currently powering a 0.5 GeV test accelerator at SLAC and several test stands, where high power components are evaluated and fundamental research is performed studying rf breakdown and dark current production. Continuing development has resulted in a Periodic Permanent Magnet (PPM) focused 50 MW klystron, tested at SLAC and subsequently contracted for manufacture by industry in England and Japan. A 75 MW version of that PPM klystron was built at SLAC and reached 75 MW, with 2.8 microsecond pulses. Based on this design, a prototype 75 MW klystron, designed for low-cost manufacture, is currently under development at SLAC, and will eventually be procured from industry in modest quantities for advanced NLC tests. Beyond these developments, the design of Multiple Beam Klystrons (MBKs) is under study at SLAC. MBKs offer the possibility of considerably lower modulator costs by producing comparable power to the klystrons now available, at much lower voltages. * This work supported by the Department of Energy under contract DE-AC03-76SF00515

  5. SSC 50 mm collider dipole cryostat design

    SciTech Connect (OSTI)

    Nicol, T.H.

    1992-04-01

    The cryostat of a Superconducting Super Collider (SSC) dipole magnet consists of all magnet components except the magnet assembly itself. It serves to support the magnet accurately and reliably within the vacuum vessel, provide all required cryogenic piping, and to insulate the cold mass from heat radiated and conducted from the environment. It must function reliably during storage, shipping and handling, normal magnet operation, quenches, and seismic excitations, and must be manufacturable at low cost. The major components of the cryostat are the vacuum vessel, thermal shields, multilayer insulation system, cryogenic piping, interconnections, and suspension system. The overall design of a cryostat for superconducting accelerator magnets requires consideration of fluid flow, proper selection of materials for their thermal and structural performance at both ambient and operating temperature, and knowledge of the environment to which the magnets will be subjected over the course of their expected operating life. This paper describes the design of the current SSC dipole magnet cryostat and includes discussions on the structural and thermal considerations involved in the development of each of the major systems.

  6. Cryostat design for the Superconducting Super Collider

    SciTech Connect (OSTI)

    Nicol, T.H.

    1990-09-01

    The cryostat of an SSC dipole magnet consists of all magnet components except the cold mass assembly. It serves to support the cold mass accurately and reliably within the vacuum vessel, provide all required cryogenic piping, and to insulate the cold mass from heat radiated and conducted from the environment. It must function reliably during storage, shipping and handling, normal magnet operation, quenches, and seismic excitations and must be manufacturable at low cost. The major components of the cryostat are the vacuum vessel, thermal shields, multilayer insulation (MLI) system, cryogenic piping, interconnections, and suspension system. The overall design of a cryostat for superconducting accelerator magnets requires consideration of fluid flow, proper selection of materials for their thermal and structural performance at both ambient and operating temperature, and knowledge of the environment to which the magnets will be subjected over the course their 25 year expected life. This paper describes the design of the current SSC collider dipole magnet cryostat and includes discussions on the thermal, structural, and dynamic considerations involved in the development of each of the major systems. 7 refs., 4 figs.

  7. Adaptive Finite Elements and Colliding Black Holes

    E-Print Network [OSTI]

    Douglas N. Arnold; Arup Mukherjee; Luc Pouly

    1997-09-15

    According to the theory of general relativity, the relative acceleration of masses generates gravitational radiation. Although gravitational radiation has not yet been detected, it is believed that extremely violent cosmic events, such as the collision of black holes, should generate gravity waves of sufficient amplitude to detect on earth. The massive Laser Interferometer Gravitational-wave Observatory, or LIGO, is now being constructed to detect gravity waves. Consequently there is great interest in the computer simulation of black hole collisions and similar events, based on the numerical solution of the Einstein field equations. In this note we introduce the scientific, mathematical, and computational problems and discuss the development of a computer code to solve the initial data problem for colliding black holes, a nonlinear elliptic boundary value problem posed in an unbounded three dimensional domain which is a key step in solving the full field equations. The code is based on finite elements, adaptive meshes, and a multigrid solution process. Here we will particularly emphasize the mathematical and algorithmic issues arising in the generation of adaptive tetrahedral meshes.

  8. Long-Range And Head-On Beam-Beam Compensation Studies in RHIC With Lessons for the LHC

    SciTech Connect (OSTI)

    Fischer, W.; Luo, Y.; Abreu, N.; Calaga, R.; Montag, C.; Robert-Demolaize, G.; Dorda, U.; Koutchouk, J.P.; Sterbini, G.; Zimmermann, F.; Kim, H.J.; Sen, T.; Shiltsev, V.; Valishev, A.; Qiang, J.; Kabel, A.; /SLAC

    2011-11-28

    Long-range as well as head-on beam-beam effects are expected to limit the LHC performance with design parameters. They are are also important consideration for the LHC upgrades. To mitigate long-range effects, current carrying wires parallel to the beam were proposed. Two such wires are installed in RHIC where they allow studying the effect of strong long-range beam-beam effects, as well as the compensation of a single long-range interaction. The tests provide benchmark data for simulations and analytical treatments. Electron lenses were proposed for both RHIC and the LHC to reduce the head-on beam-beam effect. We present the experimental long-range beam-beam program at RHIC and report on head-on compensations studies based on simulations.

  9. Long-range and head-on beam-beam compensation studies in RHIC with lessons for the LHC

    SciTech Connect (OSTI)

    Fischer, W.; Luo, Y.; Abreu, N.; Calaga, R.; Montag, C.; Robert-Demolaize, G.; Dorda, U.; Koutchouk, J.-P.; Sterbini, G.; Zimmermann, F.; Kim, H.-J.; Sen, T.; Shiltsev, V.; Valishev, A.; Qiang, J.; Kabel, A.

    2009-01-12

    Long-range as well as head-on beam-beam effects are expected to limit the LHC performance with design parameters. They are also important consideration for the LHC upgrades. To mitigate long-range effects, current carrying wires parallel to the beam were proposed. Two such wires are installed in RHIC where they allow studying the effect of strong long-range beam-beam effects, as well as the compensation of a single long-range interaction. The tests provide benchmark data for simulations and analytical treatments. Electron lenses were proposed for both RHIC and the LHC to reduce the head-on beam-beam effect. We present the experimental long-range beam-beam program at RHIC and report on head-on compensations studies based on simulations.

  10. Helium pressures in RHIC vacuum cryostats and relief valve requirements from magnet cooling line failure

    SciTech Connect (OSTI)

    Liaw, C.J.; Than, Y.; Tuozzolo, J.

    2011-03-28

    A catastrophic failure of the RHIC magnet cooling lines, similar to the LHC superconducting bus failure incident, would pressurize the insulating vacuum in the magnet and transfer line cryostats. Insufficient relief valves on the cryostats could cause a structural failure. A SINDA/FLUINT{reg_sign} model, which simulated the 4.5K/4 atm helium flowing through the magnet cooling system distribution lines, then through a line break into the vacuum cryostat and discharging via the reliefs into the RHIC tunnel, had been developed to calculate the helium pressure inside the cryostat. Arc flash energy deposition and heat load from the ambient temperature cryostat surfaces were included in the simulations. Three typical areas: the sextant arc, the Triplet/DX/D0 magnets, and the injection area, had been analyzed. Existing relief valve sizes were reviewed to make sure that the maximum stresses, caused by the calculated maximum pressures inside the cryostats, did not exceed the allowable stresses, based on the ASME Code B31.3 and ANSYS results. The conclusions are as follows: (1) The S/F simulation results show that the highest internal pressure in the cryostats, due to the magnet line failure, is {approx}37 psig (255115 Pa); (2) Based on the simulation, the temperature on the cryostat chamber, INJ Q8-Q9, could drop to 228 K, which is lower than the material minimum design temperature allowed by the Code; (3) Based on the ASME Code and ANSYS results, the reliefs on all the cryostats inside the RHIC tunnel are adequate to protect the vacuum chambers when the magnet cooling lines fail; and (4) In addition to the pressure loading, the thermal deformations, due to the temperature decrease on the cryostat chambers, could also cause a high stress on the chamber, if not properly supported.

  11. Grid Interface Challenges and Candidate Solutions for the Compact Linear Collider’s (CLIC) Klystron Modulators

    E-Print Network [OSTI]

    Aguglia, D; Watson, A; Clare, J; Wheeler, P

    2014-01-01

    The Compact Linear Collider (CLIC) is a linear electron-positron accelerator under study at CERN, in view of exploring a new leptons collision energy region (0.5TeV to 5TeV). This complex requires ~1600 klystrons fed by highly efficient and controllable power electronics for a convenient power connection to the utility grid. This paper presents the challenges and evaluates several possible structures for the power system. Discussion are provided regarding the candidate topologies according to the converters’ ratings / number and considering reliability, modularity, and redundancy.

  12. The polarized electron beam for the SLAC Linear Collider

    E-Print Network [OSTI]

    M. Woods

    1996-11-09

    The SLAC Linear Collider has been colliding a polarized electron beam with an unpolarized positron beam at the Z^0 resonance for the SLD experiment since 1992. An electron beam polarization of close to 80% has been achieved for the experiment at luminosities up to 8x10^29 cm^-2 s^-1. This is the world's first and only linear collider, and is a successful prototype for the next generation of high energy electron linear colliders. This paper discusses polarized beam operation for the SLC, and includes aspects of the polarized source, spin transport and polarimetry. Presented at the 12th International Symposium on High Energy Spin Physics held at Amsterdam, The Netherlands September 10-14, 1996.

  13. Mass, Spin, and Physics Beyond the Standard Model at Colliders

    E-Print Network [OSTI]

    Klemm, William Lathrop

    2011-01-01

    E. Skillman, “New BBN limits on physics beyond the standardH. Simmons, “Multi - jet physics at hadron colliders,” Nucl.Group], “Review of particle physics,” Phys. Lett. B [108] J.

  14. SPADs for Vertex Tracker detectors in Future Colliders

    E-Print Network [OSTI]

    Vilella, E; Vila, A; Dieguez, A

    2015-01-01

    Physics aims at the future linear colliders impose such stringent requirements on detector systems that exceed those met by any previous technology. Amongst other novel technologies, SPADs (Single Photon Avalanche Diodes) detectors are being developed to track high energy particles at ILC (International Linear Collider) and CLIC (Compact LInear Collider). These sensors offer outstanding qualities, such as an extraordinary high sensitivity, ultra-fast response time and virtually infinite gain, in addition to compatibility with standard CMOS technologies. As a result, SPAD detectors enable the direct conversion of a single particle event onto a CMOS digital signal in the sub-nanosecond time scale, which leads to the possibility of single BX (bunch crossing) resolution at some particle colliders. However, SPAD detectors suffer from two main problems, namely the noise pulses generated by the sensor and the low fill-factor. The noise pulses worsen the detector occupancy, while the low fill-factor reduces the detec...

  15. Rhetorical strategies in the campaign for the Superconducting Super Collider 

    E-Print Network [OSTI]

    Taylor, Karen Michelle

    1996-01-01

    The campaign supporting the development and construction of the Superconducting Super Collider provides opportunities to further investigate the rhetoric of science as it borders on political rhetoric. Aristotelian rhetorical theory is used....

  16. TESLA*HERA as Lepton (Photon)-Hadron Collider

    E-Print Network [OSTI]

    O. Yavas; A. K. Ciftci; S. Sultansoy

    2000-04-11

    New facilities for particle and nuclear physics research, which will be available due to constructing the TESLA linear electron-positron collider tangentially to the HERA proton ring, are discussed.

  17. Chemical freeze-out parameters in Beam Energy Scan Program of STAR at RHIC

    E-Print Network [OSTI]

    Sabita Das

    2014-12-01

    The STAR experiment at RHIC has completed its first phase of the Beam Energy Scan (BES-I) program to understand the phase structure of the quantum chromodynamics (QCD). The bulk properties of the system formed in Au+Au collisions at different center of mass energy $\\sqrt{s_{NN}} = $ 7.7, 11.5, 19.6, 27, and 39 GeV have been studied from the data collected in the year 2010 and 2011. The centrality and energy dependence of mid-rapidity ($|y|$ chemical freeze-out parameters are extracted using measured particle ratios within the framework of a statistical model.

  18. A precise in situ calibration of the RHIC H-Jet polarimeter

    SciTech Connect (OSTI)

    Poblaguev, A. A.

    2014-03-05

    Two new methods of calibration of the hydrogen jet target polarimeter (H-Jet) at RHIC are discussed. First method is based on the measurement of low amplitude signal time of fast particles penetrating through detector. The second, geometry based, method employs correlation between z-coordinate of the recoil proton and its kinetic energy. Both methods can be used for in situ calibration of the H-Jet polarimeter. These two methods are compared with a traditional calibration of the H-Jet which uses ?-sources.

  19. Electroweak symmetry breaking by strong dynamics and the collider phenomenology

    SciTech Connect (OSTI)

    Timothy L. Barklow et al.

    2002-12-23

    We discuss the possible signatures in the electroweak symmetry breaking sector by new strong dynamics at future hadron colliders such as the Tevatron upgrade, the LHC and VLHC, and e{sup +}e{sup -} linear colliders. Examples include a heavy Higgs-like scalar resonance, a heavy Technicolor-like vector resonance and pseudo-Goldstone states, non-resonance signatures via enhanced gauge-boson scattering and fermion compositeness.

  20. The Higgs boson and the International Linear Collider

    E-Print Network [OSTI]

    Borzumati, Francesca

    2014-01-01

    The Higgs boson will be subject of intense experimental searches in future high-energy experiments. In addition to the effort made at the Large Hadron Collider, where it was discovered, it will be the major subject of study at the International Linear Collider. We review here the reasons for that and some of the issues to be tackled at this future accelerator, in particular that of the precision of the Higgs-boson couplings.