Sample records for nuclear collision length

  1. RELATIVISTIC NUCLEAR COLLISIONS: THEORY

    E-Print Network [OSTI]

    Gyulassy, M.

    2010-01-01T23:59:59.000Z

    Effects in Relativistic Nuclear Collisions", Preprint LBL-Pion Interferometry of Nuclear Collisions. 18.1 M.Gyulassy,was supported by the Office of Nuclear Physics of the U.S.

  2. Constraints on the Path-Length Dependence of Jet Quenching in Nuclear Collisions at RHIC and LHC

    E-Print Network [OSTI]

    Barbara Betz; Miklos Gyulassy

    2014-10-17T23:59:59.000Z

    Recent data on the high-pT pion nuclear modification factor, $R_{AA}(p_T)$, and its elliptic azimuthal asymmetry, $v_2(p_T)$, from RHIC/BNL and LHC/CERN are analyzed in terms of a wide class of jet-energy loss models coupled to different (2+1)d transverse plus Bjorken expanding hydrodynamic fields. We test the consistency of each model by demanding a simultaneous account of the azimuthal, the transverse momentum, and the centrality dependence of the data at both 0.2 and 2.76 ATeV energies. We find a rather broad class of jet-energy independent energy-loss models $dE/dx= \\kappa(T) x^z T^{2+z} \\zeta_q$ that, when coupled to bulk constrained temperature fields T(x,t), can account for the current data at the $\\chi^2energy-loss fluctuations via a convenient scaling factor distributed in a finite range $0energy loss model with a temperature-independent jet-medium coupling as well as a near-$T_c$ dominated, pQCD-inspired energy-loss scenario are shown to be inconsistent with the LHC data, once the parameters are constrained by fitting to RHIC results, we find several new solutions with a temperature-dependent jet-medium coupling. We conclude that the current level of statistical and systematic uncertainties of the measured data does not allow a constraint on the path-length exponent z to a range narrower than [0-2].

  3. Relativistic Nuclear Collisions

    E-Print Network [OSTI]

    Reinhard Stock

    2009-07-29T23:59:59.000Z

    A comprehensive introduction is given to the field of relativistic nuclear collisions, and the phase diagram of strongly interacting matter. The content of this complex of reviews is shown.

  4. PROBING DENSE NUCLEAR MATTER VIA NUCLEAR COLLISIONS

    E-Print Network [OSTI]

    Stocker, H.

    2012-01-01T23:59:59.000Z

    University of California. LBL-12095 Probing Dense NuclearMatter Nuclear Collisions* v~a H. Stocker, M.Gyulassy and J. Boguta Nuclear Science Division Lawrence

  5. Critical QCD in Nuclear Collisions

    E-Print Network [OSTI]

    N. G. Antoniou; Y. F. Contoyiannis; F. K. Diakonos; G. Mavromanolakis

    2005-05-20T23:59:59.000Z

    A detailed study of correlated scalars, produced in collisions of nuclei and associated with the $\\sigma$-field fluctuations, $(\\delta \\sigma)^2= $, at the QCD critical point (critical fluctuations), is performed on the basis of a critical event generator (Critical Monte-Carlo) developed in our previous work. The aim of this analysis is to reveal suitable observables of critical QCD in the multiparticle environment of simulated events and select appropriate signatures of the critical point, associated with new and strong effects in nuclear collisions.

  6. NUCLEAR FLUID DYNAMICS VERSUS INTRANUCLEAR CASCADE--POSSIBLE EVIDENCE FOR COLLECTIVE FLOW IN CENTRAL HIGH ENERGY NUCLEAR COLLISIONS

    E-Print Network [OSTI]

    Stocker, H.

    2012-01-01T23:59:59.000Z

    Flow in Central High Energy Nuclear Collisions H. Stockera,theoretical models of high energy nuclear collisions andunder Contract High energy nuclear collisions offer a unique

  7. Electromagnetic radiation from relativistic nuclear collisions

    E-Print Network [OSTI]

    Charles Gale; Kevin L. Haglin

    2003-06-16T23:59:59.000Z

    We review some of the results obtained in the study of the production of electromagnetic radiation in relativistic nuclear collisions. We concentrate on the emission of real photons and dileptons from the hot and dense strongly interacting phases of the reaction. We examine the contributions from the partonic sector, as well as those from the nonperturbative hadronic sector. We examine the current data, some of the predictions for future measurements, and comment on what has been learnt so far.

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

    E-Print Network [OSTI]

    Xu, Nu

    2006-01-01T23:59:59.000Z

    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

  9. Proposal for study of $\\pi^{-}$ nucleur collisions in nuclear emulsion exposed in a pulsed magnetic field

    E-Print Network [OSTI]

    CERN. Geneva. SPS Experiments Committee

    1980-01-01T23:59:59.000Z

    Proposal for study of $\\pi^{-}$ nucleur collisions in nuclear emulsion exposed in a pulsed magnetic field

  10. Transport-constrained extensions of collision and track length estimators for solutions of radiative transport problems

    SciTech Connect (OSTI)

    Kong, Rong, E-mail: kongr413@yahoo.com [Veros Software Inc., 2333 N. Broadway, Santa Ana, CA 92706 (United States)] [Veros Software Inc., 2333 N. Broadway, Santa Ana, CA 92706 (United States); Spanier, Jerome, E-mail: jspanier@uci.edu [Beckman Laser Institute and Medical Clinic, 1002 Health Science Road E., University of California, Irvine, CA 92612 (United States)] [Beckman Laser Institute and Medical Clinic, 1002 Health Science Road E., University of California, Irvine, CA 92612 (United States)

    2013-06-01T23:59:59.000Z

    In this paper we develop novel extensions of collision and track length estimators for the complete space-angle solutions of radiative transport problems. We derive the relevant equations, prove that our new estimators are unbiased, and compare their performance with that of more conventional estimators. Such comparisons based on numerical solutions of simple one dimensional slab problems indicate the the potential superiority of the new estimators for a wide variety of more general transport problems.

  11. Anisotropic Flow and Jet Quenching in Relativistic Nuclear Collisions

    E-Print Network [OSTI]

    Qin, Guang-You

    2015-01-01T23:59:59.000Z

    The exploration of the strong-interaction matter under extreme conditions is one of the main goals of relativistic heavy-ion collisions. We provide some of the main results on the novel properties of quark-gluon plasma, with particular focus given to the strong collectivity and the color opaqueness exhibited by such hot and dense matter produced in high-energy nuclear collisions at RHIC and the LHC.

  12. Anisotropic Flow and Jet Quenching in Relativistic Nuclear Collisions

    E-Print Network [OSTI]

    Guang-You Qin

    2015-02-09T23:59:59.000Z

    The exploration of the strong-interaction matter under extreme conditions is one of the main goals of relativistic heavy-ion collisions. We provide some of the main results on the novel properties of quark-gluon plasma, with particular focus given to the strong collectivity and the color opaqueness exhibited by such hot and dense matter produced in high-energy nuclear collisions at RHIC and the LHC.

  13. Gluon Radiation and Coherent States in Ultrarelativistic Nuclear Collisions

    E-Print Network [OSTI]

    Sergei G. Matinyan; Berndt Mueller; Dirk H. Rischke

    1997-05-14T23:59:59.000Z

    We explore the correspondence between classical gluon radiation and quantum radiation in a coherent state for gluons produced in ultrarelativistic nuclear collisions. The expectation value of the invariant momentum distribution of gluons in the coherent state is found to agree with the gluon number distribution obtained classically from the solution of the Yang-Mills equations. A criterion for the applicability of the coherent state formalism to the problem of radiation in ultrarelativistic nucleus-nucleus collisions is discussed. This criterion is found to be fulfilled for midrapidity gluons with perturbative transverse momenta larger than about 1-2 GeV and produced in collisions between valence partons.

  14. Multiphase transport model for relativistic nuclear collisions 

    E-Print Network [OSTI]

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

    2000-01-01T23:59:59.000Z

    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. Specifically, the Zhang's parton...

  15. Multiphase transport model for relativistic nuclear collisions

    E-Print Network [OSTI]

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

    2000-01-01T23:59:59.000Z

    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. Specifically, the Zhang's parton...

  16. Alternative ansatz to wounded nucleon and binary collision scaling in high-energy nuclear collisions

    E-Print Network [OSTI]

    J. Scott Moreland; Jonah E. Bernhard; Steffen A. Bass

    2015-06-07T23:59:59.000Z

    We introduce TRENTO, a new parametric initial condition model for high-energy nuclear collisions based on eikonal entropy deposition via a "reduced thickness" function. The model simultaneously describes experimental proton-proton, proton-nucleus, and nucleus-nucleus multiplicity distributions, and generates nucleus-nucleus eccentricity harmonics consistent with experimental flow constraints. In addition, the model is compatible with ultra-central uranium-uranium data unlike existing models that include binary collision terms.

  17. Hadron Production at Forward Rapidity in Nuclear Collisions at RHIC

    E-Print Network [OSTI]

    . The net-proton yield in the same system is compared with that from AGS and SPS energies to study the high collisions, hadron production, net-proton, nuclear mod- ification factor, Cronin effect, jet-quenching 1 of fluid dynamics in their interpretation. Hydrodynamics properties of the expanding matter created

  18. Nuclear effects on J/? production in proton-nucleus collisions

    E-Print Network [OSTI]

    Chun-Gui Duan; Jian-Chao Xu; Li-Hua Song

    2011-09-25T23:59:59.000Z

    The study of nuclear effects for J/{\\psi} production in proton-nucleus collisions is crucial for a correct interpretation of the J/{\\psi} suppression patterns experimentally observed in heavy-ion collisions. By means of three representative sets of nuclear parton distribution, the energy loss effect in the initial state and the nuclear absorption effect in the final state are taken into account in the uniform framework of the Glauber model. A leading order phenomenological analysis is performed on J/{\\psi} production cross-section ratios RW/Be(xF) for the E866 experimental data. The J/{\\psi} suppression is investigated quantitatively due to the different nuclear effects. It is shown that the energy loss effect with resulting in the suppression on RW/Be(xF) is more important than the nuclear effects on parton distributions in high xF region. The E866 data in the small xF keep out the nuclear gluon distribution with a large anti-shadowing effect. However, the new HERA-B measurement is not in support of the anti-shadowing effect in the nuclear gluon distribution. It is found that the J/{\\psi}-nucleon inelastic cross section {\\sigma} J/{\\psi} abs depends on the kinematical variable xF, and increases as xF in the region xF > 0.2. 1 Introduction

  19. Physics of Nuclear Collisions at High Energy

    SciTech Connect (OSTI)

    Hwa, Rudolph C.

    2012-05-01T23:59:59.000Z

    A wide range of problems has been investigated in the research program during the period of this grant. Although the major effort has been in the subject of heavy-ion collisions, we have also studied problems in biological and other physical systems. The method of analysis used in reducing complex data in multiparticle production to simple descriptions can also be applied to the study of complex systems of very different nature. Phase transition is an important phenomenon in many areas of physics, and for heavy-ion collisions we study the fluctuations of multiplicities at the critical point. Human brain activities as revealed in EEG also involve fluctuations in time series, and we have found that our experience enables us to find the appropriate quantification of the fluctuations in ways that can differentiate stroke and normal subjects. The main topic that characterizes the research at Oregon in heavy-ion collisions is the recombination model for the treatment of the hadronization process. We have avoided the hydrodynamical model partly because there is already a large community engaged in it, but more significantly we have found the assumption of rapid thermalization unconvincing. Recent results in studying LHC physics lead us to provide more evidence that shower partons are very important even at low p_T, but are ignored by hydro. It is not easy to work in an environment where the conventional wisdom regards our approach as being incorrect because it does not adhere to the standard paradigm. But that is just what a vibrant research community needs: unconventional approach may find evidences that can challenge the orthodoxy. An example is the usual belief that elliptic flow in fluid dynamics gives rise to azimuthal anisotropy. We claim that it is only sufficient but not necessary. With more data from LHC and more independent thinkers working on the subject what is sufficient as a theory may turn out to be incorrect in reality. Another area of investigation that has long been associated with this PI is the study of quark-hadron phase transition in heavy-ion collisions. Finally, at LHC enough particles are produced to make feasible the investigation of intermittency and erraticity indices that we have proposed as signatures of that phase transition.

  20. Nuclear absorption and $J/?$ suppression in Pb+Pb collisions

    E-Print Network [OSTI]

    A. K. Chaudhuri

    2002-03-18T23:59:59.000Z

    We have analyzed the NA58 data on $J/\\psi$ suppression in Pb+Pb collisions. $J/\\psi$ production is assumed to be a two step process, (i) formation of $c\\bar{c}$ pair, which is accurately calculable in QCD and (ii) formation of $J/\\psi$ meson from the $c\\bar{c}$ pair, which can be conveniently parameterized. In a pA/AA collision, a $c\\bar{c}$ pair gain relative square momentum as it passes through the nuclear medium and some of the $c\\bar{c}$ pairs can gain enough momentum to cross the threshold to become an open charm meson, leading to suppression in pA/AA collisions. A new prescription is proposed for the gain in momentum square, consistent with Krammer process. The model without any free parameter could explain the $E_T$ dependence of $J/\\psi$ over Drell-Yan ratio.

  1. Nuclear Fusion via Triple Collisions in Solar Plasma

    E-Print Network [OSTI]

    V. B. Belyaev; D. E. Monakhov; N. Shevchenko; S. A. Sofianos; S. A. Rakityansky; M. Braun; L. L. Howell; W. Sandhas

    1997-09-09T23:59:59.000Z

    We consider several nuclear fusion reactions that take place at the center of the sun, which are omitted in the standard pp-chain model. More specifically the reaction rates of the nonradiative production of ^3He, ^7Be, and ^8B nuclei in triple collisions involving electrons are estimated within the framework of the adiabatic approximation. These rates are compared with those of the corresponding binary fusion reactions.

  2. Charmonium Transverse Momentum Distribution in High Energy Nuclear Collisions

    E-Print Network [OSTI]

    Zebo Tang; Nu Xu; Kai Zhou; Pengfei Zhuang

    2014-09-19T23:59:59.000Z

    The Charmonium transverse momentum distribution is more sensitive to the nature of the hot QCD matter created in high energy nuclear collisions, in comparison with the yield. Taking a detailed transport approach for charmonium motion together with a hydrodynamic description for the medium evolution, the cancelation between the two hot nuclear matter effects, the dissociation and the regeneration, controls the charmonium transverse momentum distribution. Especially, the second moment of the distribution can be used to differentiate between the hot mediums produced at SPS, RHIC and LHC energies.

  3. JETS OF NUCLEAR MATTER FROM HIGH ENERGY HEAVY ION COLLISIONS

    SciTech Connect (OSTI)

    Stocker, H.; Csernai, L.P.; Graebner, G.; Buchwald, G.; Kruse, H.; Cusson, R.Y.; Maruhn, J.A.; Greiner, W.

    1980-11-01T23:59:59.000Z

    The nuclear fluid dynamical model with final thermal breakup is used to study the reactions {sup 20}Ne + {sup 238}U and {sup 40} Ar + {sup 40}Ca at E{sub LAB}=390 MeV/n. Calculated double differential cross sections d{sup 2}{sigma}/d{Omega}dE are in agreement with recent experimental data. It is shown that azimuthally dependent triple differential cross sections d{sup 3}{sigma}/dEd cos{theta}d{phi} yield considerably deeper insight into the collision process and allow for snapshots of the reactions. Strongly correlated jets of nuclear matter are predicted.

  4. Electromagnetic radiation from nuclear collisions at RHIC energies

    E-Print Network [OSTI]

    Simon Turbide; Charles Gale; Evan Frodermann; Ulrich Heinz

    2007-12-20T23:59:59.000Z

    The hot and dense strongly interacting matter created in collisions of heavy nuclei at RHIC energies is modeled with relativistic hydrodynamics, and the spectra of real and virtual photons produced at mid-rapidity in these events are calculated. Several different sources are considered, and their relative importance is compared. Specifically, we include jet fragmentation, jet-plasma interactions, the emission of radiation from the thermal medium and from primordial hard collisions. Our calculations consistently take into account jet energy loss, as evaluated in the AMY formalism. We obtain results for the spectra, the nuclear modification factor (R_AA), and the azimuthal anisotropy (v_2) that agree with the photon measurements performed by the PHENIX collaboration at RHIC.

  5. Investigation of Rare Particle Production in High Energy Nuclear Collisions

    SciTech Connect (OSTI)

    None

    1999-09-02T23:59:59.000Z

    Our program is an investigation of the hadronization process through measurement of rare particle production in high energy nuclear interactions. Such collisions of heavy nuclei provide an environment similar in energy density to the conditions in the Big Bang. We are currently involved in two major experiments to study this environment, E896 at the AGS and STAR at RHIC. We have completed our physics running of E896, a search for the H dibaryon and measurement of hyperon production in AuAu collisions, and are in the process of analyzing the data. We have produced the electronics and software for the STAR trigger and will begin to use these tools to search for anti-nuclei and strange hadrons when RHIC turns on later this year.

  6. The Nuclear Symmetry Energy in Heavy Ion Collisions

    E-Print Network [OSTI]

    Wolter, Hermann

    2015-01-01T23:59:59.000Z

    In this contribution I discuss the nuclear symmetry energy in the regime of hadronic degrees of freedom. The density dependence of the symmetry energy is important from very low densities in supernova explosions, to the structure of neutron-rich nuclei around saturation density, and to several times saturation density in neutron stars. Heavy ion collisions are the only means to study this density dependence in the laboratory. Numerical simulations of transport theories are used to extract the equation-of-state, and thus also the symmetry energy. I discuss some examples, which relate particularly to the high density symmetry energy, which is of particular interest today. I review the status and point out some open problems in the determination of the symmetry energy in heavy ion collisions.

  7. Yang-Mills Radiation in Ultra-relativistic Nuclear Collisions

    E-Print Network [OSTI]

    Miklos Gyulassy; Larry McLerran

    1997-04-16T23:59:59.000Z

    The classical Yang-Mills radiation computed in the McLerran-Venugopalan model is shown to be equivalent to the gluon bremsstrahlung distribution to lowest order in pQCD. The classical distribution is also shown to match smoothly onto the conventional pQCD mini-jet distribution at a scale characteristic of the initial parton transverse density of the system. The atomic number and energy dependence of that scale is computed from available structure function information. The limits of applicability of the classical Yang-Mills description of nuclear collisions at RHIC and LHC energies are discussed.

  8. Stress tensor and bulk viscosity in relativistic nuclear collisions

    E-Print Network [OSTI]

    Fries, Rainer J.; Mueller, Berndt; Schaefer, Andreas.

    2008-01-01T23:59:59.000Z

    produced. DOI: 10.1103/PhysRevC.78.034913 PACS number(s): 25.75.Ag, 25.75.Ld, 47.75.+f I. INTRODUCTION The formation of strongly interactingmatter at supranuclear energy densities has recently been studied in great detail in nuclear reactions... in noncentral collisions, characterized by the ?elliptic? flow parameter v2. These observations are commonly understood to imply that (i) the quark and gluon matter undergoes rapid equilibration with thermalization times smaller than 1 fm/c [5], and (ii...

  9. Dynamics of heavy flavor quarks in high energy nuclear collisions

    E-Print Network [OSTI]

    Andrea Beraudo

    2014-07-22T23:59:59.000Z

    A general overview on the role of heavy quarks as probes of the medium formed in high energy nuclear collisions is presented. Experimental data compared to model calculations at low and moderate pT are exploited to extract information on the transport coefficients of the medium, on possible modifications of heavy flavor hadronization in a hot environment and to provide quantitative answers to the issue of kinetic (and chemical, at conceivable future experimental facilities) thermalization of charm. Finally, the role of heavy flavor at high pT as a tool to study the mass and color-charge dependence the jet quenching is also analyzed.

  10. DDbar Correlations probing Thermalization in High-Energy Nuclear Collisions

    E-Print Network [OSTI]

    K. Schweda; X. Zhu; M. Bleicher; S. L. Huang; H. Stoecker; N. Xu; P. Zhuang

    2006-10-30T23:59:59.000Z

    We propose to measure azimuthal correlations of heavy-flavor hadrons to address the status of thermalization at the partonic stage of light quarks and gluons in high-energy nuclear collisions. In particular, we show that hadronic interactions at the late stage cannot significantly disturb the initial back-to-back azimuthal correlations of DDbar pairs. Thus, a decrease or the complete absence of these initial correlations does indicate frequent interactions of heavy-flavor quarks and also light partons in the partonic stage, which are essential for the early thermalization of light partons.

  11. A study of nuclear stopping in central symmetric nuclear collisions at intermediate energies

    E-Print Network [OSTI]

    C. Escano-Rodriguez; D. Durand; A. Chbihi; J. D. Frankland; the INDRA Collaboration

    2005-03-14T23:59:59.000Z

    Nuclear stopping has been investigated in central symmetric nuclear collisions at intermediate energies. Firstly, it is found that the isotropy ratio, Riso, reaches a minimum near the Fermi energy and saturates or slowly increases depending on the mass of the system as the beam energy increases. An approximate scaling based on the size of the system is found above the Fermi energy suggesting the increasing role of in-medium nucleon-nucleon collisions. Secondly, the charge density distributions in velocity space, dZ/dvk and dZ/dv?, reveal a strong memory of the entrance channel and, as such, a sizeable nuclear transparency in the intermediate energy range. Lastly, it is shown that the width of the transverse velocity distribution is proportional to the beam velocity.

  12. Nuclear Equation of State: Picture from Medium Energy Heavy Ion Collisions

    E-Print Network [OSTI]

    P. Danielewicz

    2005-12-02T23:59:59.000Z

    Characteristics of the nuclear equation of state (EOS) and its importance, in particular for astrophysics, are discussed. Selected observables in nuclear collisions are sensitive to the EOS and can be used to constrain it. For central collisions, these include collective flow asymmetries, subthreshold kaon yields and isospin diffusion. Comparisons between the data and transport theory suggest an energy per nucleon that rises relatively slowly with density for symmetric matter and symmetry energy that rises relatively quickly around the normal nuclear density.

  13. Nuclear like effects in proton-proton collisions at high energy

    E-Print Network [OSTI]

    L. Cunqueiro; J. Dias de Deus; C. Pajares

    2009-09-17T23:59:59.000Z

    We show that several effects considered nuclear effects are not nuclear in the sense that they do not only occur in nucleus-nucleus and hadron-nucleus collisions but, as well, they are present in hadron-hadron (proton-proton) collisions. The matter creation mechanism in hh, hA and AA collisions is always the same. The pT suppression of particles produced in large multiplicity events compared to low multiplicity events, the elliptic flow and the Cronin effect are predicted to occur in pp collisions at LHC energies as a consequence of the obtained high density partonic medium.

  14. A new explanation to the cold nuclear matter effects in heavy ion collisions

    E-Print Network [OSTI]

    Zhi-Feng Liu

    2014-11-23T23:59:59.000Z

    The J/Psi cross section ratios of p-A/p-p under different collision energy is calculated with cold nuclear matter effects redefined in this paper. The advantage of these new definitions is that all cold nuclear matter effects have clear physical origins.The radios are compared with the corresponding experiment data and that calculated with classic nuclear effects. The ratios calculated with new definitions can reproduce almost all existing J/Psi measurements in p-A collisions more accuratly than that calculated with classic nuclear effects. Hence, this paper presents a new approach to explain cold nuclear effects in the hardproduction of quarkonium.

  15. $J/?$ production in Au+Au collisions at RHIC and the nuclear absorption

    E-Print Network [OSTI]

    A. K. Chaudhuri

    2006-11-09T23:59:59.000Z

    It is shown that a QCD based nuclear absorption model, with few parameters fixed to reproduce experimental $J/\\psi$ yield in 200 GeV pp/pA and 450 GeV pA collisions can explain the preliminary PHENIX data on the centrality dependence of $J/\\psi$ suppression in Cu+Cu collisions at RHIC energy, $\\sqrt{s_{NN}}$=200 GeV. However, the model does not give satisfactory description to the preliminary PHENIX data on the centrality dependence of $J/\\psi$ suppression in Au+Au collisions. The analysis suggest that in Au+Au collisions, $J/\\psi$ are suppressed in a medium unlike the medium produced in SPS energy nuclear collisions or in RHIC energy Cu+Cu collisions.

  16. Minijet transverse energy production in the next-to-leading order in hadron and nuclear collisions

    E-Print Network [OSTI]

    A. V. Leonidov; D. M. Ostrovsky

    1998-11-23T23:59:59.000Z

    The transverse energy flow generated by minijets in hadron and nuclear collisions into a given rapidity window in the central region is calculated in the next-to-leading (NLO) order in QCD at RHIC and LHC energies. The NLO transverse energy production in pp collisions cross sections are larger than the LO ones by the factors of K_{RHIC} ~ 1.9 and K_{LHC} ~ 2.1 at RHIC and LHC energies correspondingly. These results were then used to calculate transverse energy spectrum in nuclear collisions in a Glauber geometrical model. We show that accounting for NLO corrections in the elementary pp collisions leads to a substantial broadening of the E_{perp} distribution for the nuclear ones, while its form remains practically unchanged.

  17. Initial state in relativistic nuclear collisions and Color Glass Condensate

    E-Print Network [OSTI]

    F. Gelis

    2014-12-01T23:59:59.000Z

    In this talk, I discuss recent works related to the pre-hydrodynamical stages of ultra-relativistic heavy ion collisions.

  18. Effective-energy budget in multiparticle production in nuclear collisions

    E-Print Network [OSTI]

    Aditya Nath Mishra; Raghunath Sahoo; Edward K. G. Sarkisyan; Alexander S. Sakharov

    2014-11-24T23:59:59.000Z

    The dependencies of charged particle pseudorapidity density and transverse energy pseudorapidity density at midrapidity on the collision energy and on the number of nucleon participants, or centrality, measured in nucleus-nucleus collisions are studied in the energy range spanning a few GeV to a few TeV per nucleon. The model in which the multiparticle production is driven by the dissipating effective energy of participants is introduced. The model is based on the earlier proposed approach, combining the constituent quark picture together with Landau relativistic hydrodynamics shown to interrelate the measurements from different types of collisions. Within this model, the dependence on the number of participants in heavy-ion collisions are found to be well described in terms of the effective energy defined as a centrality-dependent fraction of the collision energy. For both variables under study, the effective energy approach reveals a similarity in the energy dependence obtained for the most central collisions and centrality data in the entire available energy range. Predictions are made for the investigated dependencies for the forthcoming higher energy measurements in heavy-ion collisions at the LHC.

  19. Multihadron production dynamics exploring energy balance in hadronic to nuclear collisions

    E-Print Network [OSTI]

    Sarkisyan, Edward K G; Sahoo, Raghunath; Sakharov, Alexander S

    2015-01-01T23:59:59.000Z

    The multihadron production in nucleus-nucleus collisions and its interrelation with that in (anti)proton-proton interactions are studied by exploring the charged particle mean multiplicity collision-energy and centrality dependencies in the measurements to date. The study is performed in the framework of the recently proposed effective-energy approach which, under the proper scaling of the collision energy, combines the constituent quark picture with Landau relativistic hydrodynamics counting for the centrality-defined effective energy of participants and relating different types of collisions. Within this approach, the multiplicity energy dependence and the pseudorapidity spectra from the most central nuclear collisions are well reproduced. The study of the multiplicity centrality dependence reveals a new scaling between the measured pseudorapidity spectra and the calculations. By means of this scaling, called the energy balanced limiting fragmentation scaling, one reproduces the pseudorapidity spectra for a...

  20. INDEPENDENT PARTICLE ASPECTS OF NUCLEAR DYNAMICS

    E-Print Network [OSTI]

    Robel, M.C.

    2011-01-01T23:59:59.000Z

    situations: nuclear vibrations, fission, collisions, theformulae to nuclear vibrations, fission, collisions, thenuclear phenomena: nuclear vibrations, fission, collisions,

  1. J/Psi suppression in ultrarelativistic nuclear collisions 

    E-Print Network [OSTI]

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

    2000-01-01T23:59:59.000Z

    - though all these signals have been observed in heavy ion collisions at CERN SPS, alternative explanations without in- voking the formation of the quark-gluon plasma have also been proposed. As the QGP is expected to be produced at RHIC... experiments at the Relativistic Heavy Ion Collider ~RHIC!, which allows collisions at much high energies than those available previously, are expected to provide a better oppor- tunity to create the quark-gluon plasma and to study its prop- erties. Since...

  2. Nuclear modification and azimuthal anisotropy of D mesons produced in relativistic heavy ion collision

    E-Print Network [OSTI]

    Younus, Mohammed

    2015-01-01T23:59:59.000Z

    In this paper we present a phenomenological treatment of charm quark energy loss before fragmenting into D mesons and calculate nuclear modification factor, '$R_{AA}$' and azimuthal anisotropy, '$v_2$' of D mesons for lead on lead collision at LHC energy of $\\sqrt{s}$=2.76 A TeV.

  3. Probing Shadowed Nuclear Sea with Massive Gauge Bosons in the Future Heavy-Ion Collisions

    E-Print Network [OSTI]

    Ru, Peng; Wang, Enke; Zhang, Wei-Ning

    2015-01-01T23:59:59.000Z

    The production of the massive bosons $Z^0$ and $W^{\\pm}$ could provide an excellent tool to study cold nuclear matter effects and the modifications of nuclear parton distribution functions (nPDFs) relative to parton distribution functions (PDFs) of a free proton in high energy nuclear reactions at the LHC as well as in heavy-ion collisions (HIC) with much higher center-of mass energies available in the future colliders. In this paper we calculate the rapidity and transverse momentum distributions of the vector boson and their nuclear modification factors in p+Pb collisions at $\\sqrt{s_{NN}}=63$TeV and in Pb+Pb collisions at $\\sqrt{s_{NN}}=39$TeV in the framework of perturbative QCD by utilizing three parametrization sets of nPDFs: EPS09, DSSZ and nCTEQ. It is found that in heavy-ion collisions at such high colliding energies, both the rapidity distribution and the transverse momentum spectrum of vector bosons are considerably suppressed in wide kinematic regions with respect to p+p reactions due to large nucl...

  4. Low Energy Nuclear Structure from Ultra-relativistic Heavy-Light Ion collisions

    E-Print Network [OSTI]

    Enrique Ruiz Arriola; Wojciech Broniowski

    2014-11-21T23:59:59.000Z

    The search for specific signals in ultra-relativistic heavy-light ion collisions addressing intrinsic geometric features of nuclei may open a new window to low energy nuclear structure. We discuss specifically the phenomenon of {\\alpha}-clustering in $^{12}$C when colliding with $^{208}$Pb at almost the speed of light.

  5. Nuclear Stopping in Au Au Collisions at I. G. Bearden,7

    E-Print Network [OSTI]

    , Strasbourg, France 3 Institute of Nuclear Physics, Krakow, Poland 4 Smoluchkowski Institute of Physics, Jagiellonian University, Krakow, Poland 5 Johns Hopkins University, Baltimore, Maryland 21218, USA 6 New York, and increases to dN=dy 12 at y 3. The data show that collisions at this energy exhibit a high degree

  6. J/Psi suppression in ultrarelativistic nuclear collisions

    E-Print Network [OSTI]

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

    2000-01-01T23:59:59.000Z

    circles for Au1Au col- lisions and open circles for S1S collisions. The solid lines are polynomial fits to the above results using the form rc(t)5a01a1t1a2t21a3t3 for tmin,t,tmax , with rc(t) 5rc(tmin) for t,tmin and rc(t)50 for t.tmax . For the par...

  7. Low Density Nuclear Matter in Heavy Ion Collisions 

    E-Print Network [OSTI]

    Qin, Lijun

    2010-01-14T23:59:59.000Z

    The symmetry energy is the energy difference between symmetric nuclear matter and pure neutron matter at a given density. Around normal nuclear density, i.e. p/p0 =1, and temperature, i.e. T = 0, the symmetry energy is approximately 23.5 Me...

  8. Low Density Nuclear Matter in Heavy Ion Collisions

    E-Print Network [OSTI]

    Qin, Lijun

    2010-01-14T23:59:59.000Z

    2 ,a a = 93.15 MeV/c 2 , and the pairing term, B, is 0 MeV/c 2 for odd-even or even-odd nuclei, -11.2 MeV/c 2 for even-even nuclei and +11.2 MeV/c 2 for odd-odd nuclei [24, 25, 26, 27, 28]. A classical result is shown in the Fig. 2. 6 Fig. 2. Binding... dissertation project possible. vii TABLE OF CONTENTS CHAPTER Page I INTRODUCTION .......................... 1 A. General Picture of Heavy Ion Collisons ........... 1 B. Transport Models to Simulate Heavy Ion Collisions .... 2 C...

  9. A study of vorticity formation in high energy nuclear collisions

    E-Print Network [OSTI]

    Becattini, F; Rolando, V; Beraudo, A; Del Zanna, L; De Pace, A; Nardi, M; Pagliara, G; Chandra, V

    2015-01-01T23:59:59.000Z

    We present a quantitative study of vorticity formation in peripheral ultrarelativistic heavy ion collisions at sqrt(s_NN) = 200 GeV by using the ECHO-QGP numerical code, implementing relativistic dissipative hydrodynamics in the causal Israel-Stewart framework in 3+1 dimensions with an initial Bjorken flow profile. We consider and discuss different definitions of vorticity which are relevant in relativistic hydrodynamics. After demonstrating the excellent capabilities of our code, we show that, with the initial conditions needed to reproduce the measured directed flow in peripheral collisions corresponding to an average impact parameter b=11.6 fm and with the Bjorken flow profile for a viscous Quark Gluon Plasma with eta/s=0.16 fixed, a vorticity of up to 0.05 c/fm can develop at freezeout. The ensuing polarization of Lambda baryons is at most of the order of 1% at midrapidity. We show that the amount of developed directed flow is sensitive to both the initial angular momentum of the plasma and its viscosity.

  10. The effect of partonic wind on charm quark correlations in high-energy nuclear collisions

    E-Print Network [OSTI]

    X. Zhu; N. Xu; P. Zhuang

    2007-09-03T23:59:59.000Z

    In high-energy collisions, massive heavy quarks are produced back-to-back initially and they are sensitive to early dynamical conditions. The strong collective partonic wind from the fast expanding quark-gluon plasma created in high-energy nuclear collisions modifies the correlation pattern significantly. As a result, the angular correlation function for D$\\bar{\\rm D}$ pairs is suppressed at the angle $\\Delta\\phi=\\pi$. While the hot and dense medium in collisions at RHIC ($\\sqrt{s_{NN}}=200$ GeV) can only smear the initial back-to-back D$\\bar {\\rm D}$ correlation, a clear and strong near side D$\\bar{\\rm D}$ correlation is expected at LHC ($\\sqrt{s_{NN}}=5500$ GeV).

  11. On the balance energy and nuclear dynamics in peripheral heavy-ion collisions

    E-Print Network [OSTI]

    Rajiv Chugh; Rajeev K. Puri

    2010-03-16T23:59:59.000Z

    We present here the system size dependence of balance energy for semi-central and peripheral collisions using quantum molecular dynamics model. For this study, the reactions of $Ne^{20}+Ne^{20}$, $Ca^{40}+Ca^{40}$, $Ni^{58}+Ni^{58}$, $Nb^{93}+Nb^{93}$, $Xe^{131}+Xe^{131}$ and $Au^{197}+Au^{197}$ are simulated at different incident energies and impact parameters. A hard equation of state along with nucleon-nucleon cross-sections between 40 - 55 mb explains the data nicely. Interestingly, balance energy follows a power law $\\propto{A^{\\tau}}$ for the mass dependence at all colliding geometries. The power factor $\\tau$ is close to -1/3 in central collisions whereas it is -2/3 for peripheral collisions suggesting stronger system size dependence at peripheral geometries. This also suggests that in the absence of momentum dependent interactions, Coulomb's interaction plays an exceedingly significant role. These results are further analyzed for nuclear dynamics at the balance point.

  12. Probe the QCD phase diagram with ?-mesons in high energy nuclear collisions

    E-Print Network [OSTI]

    B. Mohanty; N. Xu

    2009-01-03T23:59:59.000Z

    High-energy nuclear collision provide a unique tool to study the strongly interacting medium. Recent results from the Relativistic Heavy Ion Collider (RHIC) on \\phi-meson production has revealed the formation of a dense partonic medium. The medium constituents are found to exhibit collective behaviour initiated due to partonic interactions in the medium. We present a brief review of the recent results on \\phi production in heavy-ion collisions at RHIC. One crucial question is where, in the phase diagram, does the transition happen for the matter changing from hadronic to partonic degrees of freedom. We discuss how \\phi-meson elliptic flow in heavy-ion collisions can be used for the search of the QCD phase boundary.

  13. On the balance energy and nuclear dynamics in peripheral heavy-ion collisions

    E-Print Network [OSTI]

    Chugh, Rajiv

    2010-01-01T23:59:59.000Z

    We present here the system size dependence of balance energy for semi-central and peripheral collisions using quantum molecular dynamics model. For this study, the reactions of $Ne^{20}+Ne^{20}$, $Ca^{40}+Ca^{40}$, $Ni^{58}+Ni^{58}$, $Nb^{93}+Nb^{93}$, $Xe^{131}+Xe^{131}$ and $Au^{197}+Au^{197}$ are simulated at different incident energies and impact parameters. A hard equation of state along with nucleon-nucleon cross-sections between 40 - 55 mb explains the data nicely. Interestingly, balance energy follows a power law $\\propto{A^{\\tau}}$ for the mass dependence at all colliding geometries. The power factor $\\tau$ is close to -1/3 in central collisions whereas it is -2/3 for peripheral collisions suggesting stronger system size dependence at peripheral geometries. This also suggests that in the absence of momentum dependent interactions, Coulomb's interaction plays an exceedingly significant role. These results are further analyzed for nuclear dynamics at the balance point.

  14. Nuclear absorption and anomalous $J/?$ suppression in Pb+Pb collisions

    E-Print Network [OSTI]

    A. K. Chaudhuri

    2003-07-31T23:59:59.000Z

    We discuss $J/\\psi$ suppression in a QCD based nuclear absorption model. Centrality dependence of $J/\\psi$ suppression in S+U and in Pb+Pb collisions are explained in the model. However, the model fails to explain the centrality dependence of $\\psi\\prime$ suppression. $\\psi\\prime$ suppression in S+U or in Pb+Pb collisions require additional suppression. Additional suppression of $\\psi\\prime$, due to hadronic comovers or due to QGP formation could not be distinguished in Pb+Pb collisions. We then show that the centrality dependence of the ratio, $\\psi\\prime$ over $J/\\psi$, could possibly distinguish two scenario (e.g. QGP or hadronic comover) at RHIC energy.

  15. Forward Lambda Production and Nuclear Stopping Power in d+Au Collisions at RHIC

    E-Print Network [OSTI]

    Frank Simon; for the STAR collaboration

    2006-02-09T23:59:59.000Z

    Using the forward time projection chambers of STAR we measure the centrality dependent Lambda and Anti-Lambda yields in d+Au collisions at \\sqrt{s_{NN} = 200 GeV at forward and backward rapidities. The contributions of different processes to particle production and baryon transport are probed exploiting the inherent asymmetry of the d+Au system. While the d side appears to be dominated by multiple independent nucleon-nucleon collisions, nuclear effects contribute significantly on the Au side. Using the constraint of baryon number conservation, the rapidity loss of baryons in the incoming deuteron can be estimated as a function of centrality. This is compared to a model and to similar measurements in Au+Au, which gives insights into the nuclear stopping power at relativistic energies.

  16. Effects of nuclear absorption on the antiLambda/antiproton ratio in relativistic heavy ion collisions

    E-Print Network [OSTI]

    Fuqiang Wang; Marlene Nahrgang; Marcus Bleicher

    2012-06-30T23:59:59.000Z

    An enhanced antiLambda/antiproton ratio in heavy-ion relative to p+p collisions has been proposed as one of the signatures for the Quark-Gluon Plasma (QGP) formation. A significantly large (antiLambda+antiSigma0+1.1*antiSigma-)/antiproton ratio of 3.5 has been observed in the mid-rapidity and low transverse momentum region in central Au+Au collisions at the nucleon-nucleon center-of-mass energy of 4.9 GeV at the Alternating Gradient Synchrotron (AGS). This is an order of magnitude larger than the values in peripheral Au+Au collisions and p+p collisions at the corresponding energy. By using the Ultra-relativistic Quantum Molecular Dynamics (UrQMD) transport model, we demonstrate that the observed large ratio can be explained by strong absorption of antiprotons (~99.9%) and antiLambdas (~99%) in dense nuclear matter created in central collisions. We find within the model that the initial antiLambda/antiproton ratio, mainly from string fragmentation, does not depend on the collision centrality, and is consistent with that observed in p+p collisions. This suggests that the observed large (antiLambda+antiSigma0+1.1*antiSigma-)/antiproton ratio at the AGS does not necessarily imply the formation of the QGP. We further study the excitation function of the ratio in UrQMD, which may help in the search and study of the QGP.

  17. Nuclear k_T in d+Au Collisions from Multiparticle Jet Reconstruction at STAR

    E-Print Network [OSTI]

    Thomas Henry

    2005-11-01T23:59:59.000Z

    This paper presents the most recent nuclear k_T measurements from STAR derived from multiparticle jet reconstruction of d+Au and p+p collisions at sqrt(s)=200 GeV. Since jets reconstructed from multiple particles are relatively free of fragmentation biases, nuclear k_T can be measured with greater certainty in this way than with traditional di-hadron correlations. Multi-particle jet reconstruction can also be used for a direct measurement of the fragmentation function.

  18. Thermal dileptons in high-energy nuclear collisions

    E-Print Network [OSTI]

    Sanja Damjanovic

    2008-12-16T23:59:59.000Z

    Clear signs of excess dileptons above the known sources were found at the SPS since long. However, a real clarification of these observations was only recently achieved by NA60, measuring dimuons with unprecedented precision in 158A GeV In-In collisions. The excess mass spectrum in the region M rho -> mu+mu- annihilation. The associated rho spectral function shows a strong broadening, but essentially no shift in mass. In the region M>1 GeV, the excess is found to be prompt, not due to enhanced charm production. The inverse slope parameter Teff associated with the transverse momentum spectra rises with mass up to the rho, followed by a sudden decline above. While the initial rise, coupled to a hierarchy in hadron freeze-out, points to radial flow of a hadronic decay source, the decline above signals a transition to a low-flow source, presumably of partonic origin. The mass spectra show the steep rise towards low masses characteristic for Planck-like radiation. The polarization of the excess referred to the Collins Soper frame is found to be isotropic. All observations are consistent with a global interpretation of the excess as thermal radiation. We conclude with a short discussion of a possible link to direct photons.

  19. 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

    2014-11-13T23:59:59.000Z

    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.

  20. Suppression of soft nuclear bremsstrahlung in proton-nucleus collisions

    E-Print Network [OSTI]

    M. J. van Goethem; L. Aphecetche; J. C. S. Bacelar; H. Delagrange; J. Diaz; D. d'Enterria; M. Hoefman; R. Holzmann; H. Huisman; N. Kalantar--Nayestanaki; A. Kugler; H. Loehner; G. Martinez; J. G. Messchendorp; R. W. Ostendorf; S. Schadmand; R. H. Siemssen; R. S. Simon; Y. Schutz; R. Turrisi; M. Volkerts; H. W. Wilschut

    2001-11-30T23:59:59.000Z

    Photon energy spectra up to the kinematic limit have been measured in 190 MeV proton reactions with light and heavy nuclei to investigate the influence of the multiple-scattering process on the photon production. Relative to the predictions of models based on a quasi-free production mechanism a strong suppression of bremsstrahlung is observed in the low-energy region of the photon spectrum. We attribute this effect to the interference of photon amplitudes due to multiple scattering of nucleons in the nuclear medium.

  1. A possible evidence of the hadron-quark-gluon mixed phase formation in nuclear collisions

    E-Print Network [OSTI]

    Kizka, V A; Bugaev, K A; Oliinychenko, D R

    2015-01-01T23:59:59.000Z

    The performed systematic meta-analysis of the quality of data description (QDD) of existing event generators of nucleus-nucleus collisions allows us to extract a very important physical information. Our meta-analysis is dealing with the results of 10 event generators which describe data measured in the range of center of mass collision energies from 3.1 GeV to 17.3 GeV. It considers the mean deviation squared per number of experimental points obtained by these event generators, i.e. the QDD, as the results of independent meta-measurements. These generators and their QDDs are divided in two groups. The first group includes the generators which account for the quark-gluon plasma formation during nuclear collisions (QGP models), while the second group includes the generators which do not assume the QGP formation in such collisions (hadron gas models). Comparing the QDD of more than a hundred of different data sets of strange hadrons by two groups of models, we found two regions of the equal quality description o...

  2. Nuclear absorption and anomalous J/psi suppression in Pb+Pb collisions

    E-Print Network [OSTI]

    A. K. Chaudhuri

    2002-07-29T23:59:59.000Z

    We have studied the J/psi suppression in 158 GeV/c Pb+Pb collisions at CERN SPS. J/psi production is assumed to be a two step process, (i) formation of c bar{c} pair, which is accurately calculable in QCD and (ii) formation of J/psi meson from the c bar{c} pair, which can be conveniently parameterized. In a pA/AA collision, as the c bar{c} pair pass through the nuclear medium, it gains relative square momentum. As a result, some of the c bar{c} pairs can gain enough momentum to cross the threshold to become open charm meson, leading to suppression in pA/AA collisions. The model without any free parameter could describe the of NA50 data on centrality dependence of the ratio's; J/psi over Drell-Yan, J/psi over minimum bias and also the Drell-Yan over minimum bias. The model was used to predict J/psi suppression at RHIC energy. At RHIC energy, hard processes may be important. With hard processes included, J/psi's are strongly suppressed, in agreement with other model calculations. We also show that centrality dependence of J/psi over minimum bias ratio can be used to determine the fraction of hard processes in the collision.

  3. Evidence for radial flow of thermal dileptons in high-energy nuclear collisions

    E-Print Network [OSTI]

    NA60 Collaboration; R. Arnaldi

    2007-11-12T23:59:59.000Z

    The NA60 experiment at the CERN SPS has studied low-mass dimuon production in 158 AGeV In-In collisions. An excess of pairs above the known meson decays has been reported before. We now present precision results on the associated transverse momentum spectra. The slope parameter Teff extracted from the spectra rises with dimuon mass up to the rho, followed by a sudden decline above. While the initial rise is consistent with the expectations for radial flow of a hadronic decay source, the decline signals a transition to an emission source with much smaller flow. This may well represent the first direct evidence for thermal radiation of partonic origin in nuclear collisions.

  4. Thermal hard-photons probing multifragmentation in nuclear collisions around the Fermi energy

    E-Print Network [OSTI]

    D. G. d'Enterria; G. Martínez

    2000-07-06T23:59:59.000Z

    Hard-photon (E$_{\\gamma} >$ 30 MeV) emission issuing from proton-neutron bremsstrahlung collisions is investigated in four different heavy-ion reactions at intermediate bombarding energies ($^{36}$Ar+$^{197}$Au, $^{107}$Ag, $^{58}$Ni, $^{12}$C at 60{\\it A} MeV) coupling the TAPS photon spectrometer with two charged-particle multidetectors covering more than 80% of the solid angle. The hard-photon spectra of the three heavier targets result from the combination of two distinct exponential distributions with different slope parameters, a result which deviates from the behaviour expected for hard-photon production just in first-chance proton-neutron collisions. The thermal origin of the steeper bremsstrahlung component is confirmed by the characteristics of its slope and angular distribution. Such thermal hard-photons convey undisturbed information of the thermodynamical state of hot and excited nuclear systems undergoing multifragmentation.

  5. Nuclear absorption of Charmoniums in pA and AA collisions

    E-Print Network [OSTI]

    A. K. Chaudhuri

    2003-05-19T23:59:59.000Z

    We have analysed the latest NA50 data on $J/\\psi$ production in pA and AA collisions. The $J/\\psi$ production is assumed to be a two step process, (i) formation of $c\\bar{c}$ pairs, perturbatively calculable, and (ii) formation of $J/\\psi$ from the pair, a non-perturbative process, which is conviniently parametrized. In a nuclear medium, as the $c\\bar{c}$ pair passes through the nuclear medium, it gain relative square momentum and some of the pairs can gain enough square momentum to cross the threshold for open charm meson, leading to suppression in nuclear medium. Few parameters of the model were fixed from the latest high statistics NA50 pA and NA38 SU total $J/\\psi$ cross sectional data. The model then reproduces the centrality dependence of $J/\\psi$ over Drell-Yan ration in 200 GeV/c S+U and 158 GeV/c Pb+Pb collisions. We also discuss the centrality dependence of $J/\\psi$ suppression at RHIC energy.

  6. Forward Lambda Production and Nuclear Stopping Power in d + Au Collisions at sqrt(s_NN) = 200 GeV

    E-Print Network [OSTI]

    STAR Collaboration; B. I. Abelev

    2007-12-21T23:59:59.000Z

    We report the measurement of Lamda and Anti-Lamda yields and inverse slope parameters in d + Au collisions at sqrt(s_NN) = 200 GeV at forward and backward rapidities (y = +- 2.75), using data from the STAR forward time projection chambers. The contributions of different processes to baryon transport and particle production are probed exploiting the inherent asymmetry of the d + Au system. Comparisons to model calculations show that the baryon transport on the deuteron side is consistent with multiple collisions of the deuteron nucleons with gold participants. On the gold side HIJING based models do not describe the measured particle yields while models with initial state nuclear effects and/or hadronic rescattering do. The multichain model can provide a good description of the net baryon density in d + Au collisions at energies available at the BNL Relativistic Heavy Ion Collider, and the derived parameters of the model agree with those from nuclear collisions at lower energies.

  7. Overview of event-by-event analysis of high energy nuclear collisions

    E-Print Network [OSTI]

    Tapan K. Nayak

    2007-06-19T23:59:59.000Z

    The event-by-event analysis of high energy nuclear collisions aims at revealing the richness of the underlying event structures and provide unique measures of dynamical fluctuations associated with QGP phase transition. The major challenge in these studies is to separate the dynamical fluctuations from the many other sources which contribute to the measured values. We present the fluctuations in terms of event multiplicity, mean transverse momentum, elliptic flow, source sizes, particle ratios and net charge distributions. In addition, we discuss the effect of long range correlations, disoriented chiral condensates and presence of jets. A brief review of various probes used for fluctuation studies and available experimental results are presented.

  8. Particle distribution and nuclear stopping in Au-Au collisions at $\\sqrt{s_{NN}}$=200 GeV

    E-Print Network [OSTI]

    L. L. Zhu; C. B. Yang

    2006-05-18T23:59:59.000Z

    The transverse momentum distribution of produced charged particles is investigated for gold-gold collisions at $\\sqrt{s_{NN}}=200$ GeV. A simple parameterization is suggested for the particle distribution based on the nuclear stopping effect. The model can fit very well both the transverse momentum distributions at different pseudo-rapidities and the pseudo-rapidity distributions at different centralities. The ratio of rapidity distributions for peripheral and central collisions is calculated and compared with the data.

  9. Testing nuclear parton distributions with pA collisions at the LHC

    E-Print Network [OSTI]

    Paloma Quiroga-Arias; Jose Guilherme Milhano; Urs Achin Wiedemann

    2010-02-12T23:59:59.000Z

    Global perturbative QCD analyses, based on large data sets from electron-proton and hadron collider experiments, provide tight constraints on the parton distribution function (PDF) in the proton. The extension of these analyses to nuclear parton distributions (nPDF) has attracted much interest in recent years. nPDFs are needed as benchmarks for the characterization of hot QCD matter in nucleus-nucleus collisions, and attract further interest since they may show novel signatures of non-linear density-dependent QCD evolution. However, it is not known from first principles whether the factorization of long-range phenomena into process-independent parton distribution, which underlies global PDF extractions for the proton, extends to nuclear effects. As a consequence, assessing the reliability of nPDFs for benchmark calculations goes beyond testing the numerical accuracy of their extraction and requires phenomenological tests of the factorization assumption. Here we argue that a proton-nucleus collision program at the LHC would provide a set of measurements allowing for unprecedented tests of the factorization assumption underlying global nPDF fits.

  10. Testing collinear factorization and nuclear parton distributions with pA collisions at the LHC

    E-Print Network [OSTI]

    Paloma Quiroga-Arias; Jose Guilherme Milhano; Urs Achim Wiedemann

    2010-10-07T23:59:59.000Z

    Global perturbative QCD analyses, based on large data sets from electron-proton and hadron collider experiments, provide tight constraints on the parton distribution function (PDF) in the proton. The extension of these analyses to nuclear parton distributions (nPDF) has attracted much interest in recent years. nPDFs are needed as benchmarks for the characterization of hot QCD matter in nucleus-nucleus collisions, and attract further interest since they may show novel signatures of non- linear density-dependent QCD evolution. However, it is not known from first principles whether the factorization of long-range phenomena into process-independent parton distribution, which underlies global PDF extractions for the proton, extends to nuclear effects. As a consequence, assessing the reliability of nPDFs for benchmark calculations goes beyond testing the numerical accuracy of their extraction and requires phenomenological tests of the factorization assumption. Here we argue that a proton-nucleus collision program at the LHC would provide a set of measurements allowing for unprecedented tests of the factorization assumption underlying global nPDF fits.

  11. Energy and Atomic Mass Dependence of Nuclear Stopping Power in Relativistic Heavy-Ion Collisions in Interacting Gluon Model

    E-Print Network [OSTI]

    Q. J. Liu; W. Q. Chao; G. Wilk

    1995-04-05T23:59:59.000Z

    We present a Monte-Carlo simulation of energy deposition process in relativistic heavy-ion collisions based on a new realization of the Interacting-Gluon-Model (IGM) for high energy $N-N$ collisions. In particular we show results for proton spectra from collisions of $E_{lab}=200 \\ GeV/N$ $^{32}$S beam incident on $^{32}$S target and analyze the energy and mass dependence of nuclear stopping power predicted by our model. Theoretical predictions for proton rapidity distributions of both $^{208}$Pb + $^{208}$Pb collisions at $E_{lab}=160 \\ GeV/N$ CERN SPS and $^{197}$Au + $^{197}$Au at $\\sqrt{s_{NN}}=200 \\ GeV$ BNL RHIC are given.

  12. Nuclear matter effects on J/? production in asymmetric Cu+Au collisions at ?SNN=200 GeV

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

    Adare, A.

    2014-12-01T23:59:59.000Z

    We report on J/? production from asymmetric Cu+Au heavy-ion collisions at ?sNN =200 GeV at the Relativistic Heavy Ion Collider at both forward (Cu-going direction) and backward (Au-going direction) rapidities. The nuclear modification of J/? yields in Cu+Au collisions in the Au-going direction is found to be comparable to that in Au+Au collisions when plotted as a function of the number of participating nucleons. In the Cu-going direction, J/? production shows a stronger suppression. This difference is comparable in magnitude and has the same sign as the difference expected from shadowing effects due to stronger low-x gluon suppression in themore »larger Au nucleus. The relative suppression is opposite to that expected from hot nuclear matter dissociation, since a higher energy density is expected in the Au-going direction.« less

  13. Hadronic rescattering effects on multi-strange hadrons in high-energy nuclear collisions

    E-Print Network [OSTI]

    Takeuchi, Shiori; Hirano, Tetsufumi; Huovinen, Pasi; Nara, Yasushi

    2015-01-01T23:59:59.000Z

    We study the effects of hadronic rescattering on hadron distributions in high-energy nuclear collisions by using an integrated dynamical approach. This approach is based on a hybrid model combining (3+1)-dimensional ideal hydrodynamics for the quark gluon plasma (QGP), and a transport model for the hadron resonance gas. Since the hadron distributions are the result of the entire expansion history of the system, understanding the QGP properties requires investigating how rescattering during the hadronic stage affects the final distributions of hadrons. We include multi-strange hadrons in our study, and quantify the effects of hadronic rescattering on their mean transverse momenta and elliptic flow. We find that multi-strange hadrons scatter less during the hadronic stage than non-strange particles, and thus their distributions reflect the properties of the system in an earlier stage than the distributions of non-strange particles.

  14. Fluctuations of Conserved Quantities in High Energy Nuclear Collisions at RHIC

    E-Print Network [OSTI]

    Xiaofeng Luo

    2015-01-13T23:59:59.000Z

    Fluctuations of conserved quantities in heavy-ion collisions are used to probe the phase transition and the QCD critical point for the strongly interacting hot and dense nuclear matter. The STAR experiment has carried out moment analysis of net-proton (proxy for net-baryon (B)), net-kaon (proxy for net-strangeness (S)), and net-charge (Q). These measurements are important for understanding the quantum chromodynamics phase diagram. We present the analysis techniques used in the moment analysis by the STAR experiment and discuss the moments of net-proton and net-charge distributions from the first phase of the Beam Energy Scan program at the Relativistic Heavy Ion Collider.

  15. Fluctuations of Conserved Quantities in High Energy Nuclear Collisions at RHIC

    E-Print Network [OSTI]

    Luo, Xiaofeng

    2015-01-01T23:59:59.000Z

    Fluctuations of conserved quantities in heavy-ion collisions are used to probe the phase transition and the QCD critical point for the strongly interacting hot and dense nuclear matter. The STAR experiment has carried out moment analysis of net-proton (proxy for net-baryon (B)), net-kaon (proxy for net-strangeness (S)), and net-charge (Q). These measurements are important for understanding the quantum chromodynamics phase diagram. We present the analysis techniques used in the moment analysis by the STAR experiment and discuss the moments of net-proton and net-charge distributions from the first phase of the Beam Energy Scan program at the Relativistic Heavy Ion Collider.

  16. Development of Commercial-Length Nuclear Fuel Post-Irradiation Examination Capabilities at the Oak Ridge National Laboratory

    SciTech Connect (OSTI)

    Ott, Larry J [ORNL; Spellman, Donald J [ORNL; Bevard, Bruce Balkcom [ORNL; Chesser, Joel B [ORNL; Morris, Robert Noel [ORNL

    2009-01-01T23:59:59.000Z

    The U.S. Department of Energy Fissile Materials Disposition Program is pursuing disposal of surplus weapons-usable plutonium by reactor irradiation as the fissile constituent of mixed oxide (MOX) fuel. Lead test assemblies (LTAs) have been irradiated for approximately 36 months in Duke Energy s Catawba-1 nuclear power plant. Per the MOX fuel qualification plan, destructive post-irradiation examinations (PIEs) are to be performed on second-cycle rods (irradiated to an average burnup of approximately 42 GWd/MTHM). These LTA bundles are planned to be returned to the reactor and further irradiated to approximately 52 GWd/MTHM. Nondestructive and destructive PIEs of these commercially irradiated weapons-derived MOX fuel rods will be conducted at the Oak Ridge National Laboratory (ORNL) in the Irradiated Fuels Examination Laboratory (IFEL). PIE began in early 2009. In order to support the examination of the irradiated full-length (~3.66 m) MOX fuel rods, ORNL in 2004 began to develop the necessary infrastructure and equipment for the needed full-scope PIE capabilities. The preparations included modifying the IFEL building to handle a commercial spent-fuel shipping cask; procurement of cask-handling equipment and a skid to move the cask inside the building; development of in-cell handling equipment for cask unloading; and design, fabrication, and testing of the automated, state-of-the-art PIE examination equipment. This paper describes these activities and the full-scope PIE capabilities available at ORNL for commercial full-length fuel rods.

  17. Nuclear modification and elliptic flow measurements for $?$ mesons at $\\sqrt{s_{NN}}$ = 200 GeV d+Au and Au+Au collisions by PHENIX

    E-Print Network [OSTI]

    Dipali Pal

    2005-10-06T23:59:59.000Z

    We report the first results of the nuclear modification factors and elliptic flow of the phi mesons measured by the PHENIX experiment at RHIC in high luminosity Au+Au collisions at sqrt(sNN) = 200 GeV. The nuclear modification factors R_AA and R_CP of the phi follow the same trend of suppression as pi0's in Au+Au collisions. In d+Au collisions at sqrt(sNN) = 200 GeV, the phi mesons are not suppressed. The elliptic flow of the phi mesons, measured in the minimum bias Au+Au events, is statistically consistent with other identified particles.

  18. Search for the QCD critical point in nuclear collisions at the CERN SPS

    E-Print Network [OSTI]

    The NA49 Collaboration; N. G. Antoniou; F. K. Diakonos; G. Mavromanolakis

    2010-05-19T23:59:59.000Z

    Pion production in nuclear collisions at the SPS is investigated with the aim to search, in a restricted domain of the phase diagram, for power-laws in the behavior of correlations which are compatible with critical QCD. We have analyzed interactions of nuclei of different size (p+p, C+C, Si+Si, Pb+Pb) at 158$A$ GeV adopting, as appropriate observables, scaled factorial moments in a search for intermittent fluctuations in transverse dimensions. The analysis is performed for $\\pi^+\\pi^-$ pairs with invariant mass very close to the two-pion threshold. In this sector one may capture critical fluctuations of the sigma component in a hadronic medium, even if the $\\sigma$-meson has no well defined vacuum state. It turns out that for the Pb+Pb system the proposed analysis technique cannot be applied without entering the invariant mass region with strong Coulomb correlations. As a result the treatment becomes inconclusive in this case. Our results for the other systems indicate the presence of power-law fluctuations in the freeze-out state of Si+Si approaching in size the prediction of critical QCD.

  19. Ramifications of the Nuclear Symmetry Energy for Neutron Stars, Nuclei, and Heavy-Ion Collisions

    E-Print Network [OSTI]

    Andrew W. Steiner; Bao-An Li; Madappa Prakash

    2007-11-29T23:59:59.000Z

    The pervasive role of the nuclear symmetry energy in establishing some nuclear static and dynamical properties, and in governing some attributes of neutron star properties is highlighted.

  20. THE LOW-TEMPERATURE NUCLEAR SPIN EQUILIBRIUM OF H{sup +} {sub 3} IN COLLISIONS WITH H{sub 2}

    SciTech Connect (OSTI)

    Grussie, F.; Berg, M. H.; Wolf, A.; Kreckel, H. [Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg (Germany); Crabtree, K. N.; McCall, B. J. [Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801 (United States); Gaertner, S.; Schlemmer, S., E-mail: holger.kreckel@mpi-hd.mpg.de [I. Physikalisches Institut, Universitaet zu Koeln, Zuelpicher Str. 77, D-50937 Koeln (Germany)

    2012-11-01T23:59:59.000Z

    Recent observations of H{sub 2} and H{sup +} {sub 3} in diffuse interstellar sightlines revealed a difference in the nuclear spin excitation temperatures of the two species. This discrepancy comes as a surprise, as H{sup +} {sub 3} and H{sub 2} should undergo frequent thermalizing collisions in molecular clouds. Non-thermal behavior of the fundamental H{sup +} {sub 3}/H{sub 2} collision system at low temperatures was considered as a possible cause for the observed irregular populations. Here, we present measurements of the steady-state ortho/para ratio of H{sup +} {sub 3} in collisions with H{sub 2} molecules in a temperature-variable radiofrequency ion trap between 45 and 100 K. The experimental results are close to the expected thermal outcome and they agree very well with a previous micro-canonical model. We briefly discuss the implications of the experimental results for the chemistry of the diffuse interstellar medium.

  1. Azimuthal jet flavor tomography with CUJET2.0 of nuclear collisions at RHIC and LHC

    E-Print Network [OSTI]

    Jiechen Xu; Alessandro Buzzatti; Miklos Gyulassy

    2014-08-08T23:59:59.000Z

    A perturbative QCD based jet tomographic Monte Carlo model, CUJET2.0, is presented to predict jet quenching observables in relativistic heavy ion collisions at RHIC/BNL and LHC/CERN energies. This model generalizes the DGLV theory of flavor dependent radiative energy loss by including multi-scale running strong coupling effects. It generalizes CUJET1.0 by computing jet path integrations though more realistic 2+1D transverse and longitudinally expanding viscous hydrodynamical fields contrained by fits to low $p_T$ flow data. The CUJET2.0 output depends on three control parameters, $(\\alpha_{max},f_E,f_M)$, corresponding to an assumed upper bound on the vacuum running coupling in the infrared and two chromo-electric and magnetic QGP screening mass scales $(f_E \\mu(T), f_M \\mu(T))$ where $\\mu(T)$ is the 1-loop Debye mass. We compare numerical results as a function of $\\alpha_{max}$ for pure and deformed HTL dynamically enhanced scattering cases corresponding to $(f_E=1,2, f_M=0)$ to data of the nuclear modification factor, $R^f_{AA}(p_T,\\phi; \\sqrt{s}, b)$ for jet fragment flavors $f=\\pi,D, B, e$ at $\\sqrt{s}=0.2-2.76$ ATeV c.m. energies per nucleon pair and with impact parameter $b=2.4, 7.5$ fm. A $\\chi^2$ analysis is presented and shows that $R^\\pi_{AA}$ data from RHIC and LHC are consistent with CUJET2.0 at the $\\chi^2/d.o.f< 2$ level for $\\alpha_{max}=0.23-0.30$. The corresponding $\\hat{q}(E_{jet}, T)/T^3$ effective jet transport coefficient field of this model is computed to facilitate comparison to other jet tomographic models in the literature. The predicted elliptic asymmetry, $v_2(p_T;\\sqrt{s},b)$ is, however, found to significantly underestimated relative to RHIC and LHC data. We find the $\\chi^2_{v_2}$ analysis shows that $v_2$ is very sensitive to allowing even as little as 10\\% variations of the path averaged $\\alpha_{max}$ along in and out of reaction plane paths.

  2. Nuclear Effects on Hadron Production in d+Au and p+p Collisions at sqrt(s_NN)=200 GeV

    E-Print Network [OSTI]

    PHENIX Collaboration; S. S. Adler

    2006-03-08T23:59:59.000Z

    PHENIX has measured the centrality dependence of mid-rapidity pion, kaon and proton transverse momentum distributions in d+Au and p+p collisions at sqrt(s_NN) = 200 GeV. The p+p data provide a reference for nuclear effects in d+Au and previously measured Au+Au collisions. Hadron production is enhanced in d+Au, relative to independent nucleon-nucleon scattering, as was observed in lower energy collisions. The nuclear modification factor for (anti) protons is larger than that for pions. The difference increases with centrality, but is not sufficient to account for the abundance of baryon production observed in central Au+Au collisions at RHIC. The centrality dependence in d+Au shows that the nuclear modification factor increases gradually with the number of collisions suffered by each participant nucleon. We also present comparisons with lower energy data as well as with parton recombination and other theoretical models of nuclear effects on particle production.

  3. Sensitivity of Pion versus Parton-Jet Nuclear Modification Factors to the Path-Length Dependence of Jet-Energy Loss at RHIC and LHC

    E-Print Network [OSTI]

    Betz, Barbara

    2015-01-01T23:59:59.000Z

    We compare the jet-path length and beam-energy dependence of the pion nuclear modification factor and a parton-jet nuclear modification factor at RHIC and LHC. We contrast predictions based on a linear pQCD and a highly non-linear hybrid-AdS holographic model of jet-energy loss. We find that both models require a reduction of the jet-medium coupling from RHIC to LHC to account for the measured pion nuclear modification factor. In case of the parton-jet nuclear modification factor, however, which serves as a lower bound for the LO jet nuclear modification factor of reconstructed jets, the extracted data can be characterized without a reduced jet-medium coupling at LHC energies. We conclude that while reconstructed jets are sensitive to both quarks and gluons and thus provide more information than the pion nuclear modification factor, their information regarding the jet-medium coupling is limited due to the superimposition with NLO and medium effects. Hence, a detailed description of the underlying physics requ...

  4. NUCLEAR SCIENCE ANNUAL REPORT 1977-1978

    E-Print Network [OSTI]

    Schroeder, L.S.

    2011-01-01T23:59:59.000Z

    A Relation Between Nuclear Dynamics and the RenormalizationMultiplicity Distributions in Nuclear Collision M. GyulassyHigh Energy Nuclear Collisions in the Resonance Dominated

  5. HARD PARTON PHYSICS IN HIGH ENERGY NUCLEAR COLLISIONS. PROCEEDINGS OF RIKEN BNL RESEARCH CENTER WORKSHOP, VOLUME 17

    SciTech Connect (OSTI)

    CARROLL,J.

    1999-09-10T23:59:59.000Z

    The RIKEN-BNL center workshop on ''Hard parton physics in high energy nuclear collisions'' was held at BNL from March 1st-5th! 1999. The focus of the workshop was on hard probes of nucleus-nucleus collisions that will be measured at RHIC with the PHENIX and STAR detectors. There were about 45 speakers and over 70 registered participants at the workshop, with roughly a quarter of the speakers from overseas. About 60% of the talks were theory talks. A nice overview of theory for RHIC was provided by George Sterman. The theoretical talks were on a wide range of topics in QCD which can be classified under the following: (a) energy loss and the Landau-Pomeranchuk-Migdal effect; (b) minijet production and equilibration; (c) small x physics and initial conditions; (d) nuclear parton distributions and shadowing; (e) spin physics; (f) photon, di-lepton, and charm production; and (g) hadronization, and simulations of high pt physics in event generators. Several of the experimental talks discussed the capabilities of the PHENIX and STAR detectors at RHIC in measuring high pt particles in heavy ion collisions. In general, these talks were included in the relevant theory sessions. A session was set aside to discuss the spin program at RHIC with polarized proton beams. In addition, there were speakers from 08, HERA, the fixed target experiments at Fermilab, and the CERN fixed target Pb+Pb program, who provided additional perspective on a range of issues of relevance to RHIC; from jets at the Tevatron, to saturation of parton distributions at HERA, and recent puzzling data on direct photon production in fixed target experiments, among others.

  6. Nuclear astrophysics studies with ultra-peripheral heavy-ion collisions

    E-Print Network [OSTI]

    C. A. Bertulani

    2009-12-17T23:59:59.000Z

    I describe in very simple terms the theoretical tools needed to investigate ultra-peripheral nuclear reactions for nuclear astrophysics purposes. For a more detailed account, see arXiv:0908.4307.

  7. $\\eta$ meson production of high-energy nuclear collisions at NLO

    E-Print Network [OSTI]

    Dai, Wei; Zhang, Ben-Wei; Wang, Enke

    2015-01-01T23:59:59.000Z

    The transverse momentum spectrum of $\\eta$ meson in relativistic heavy-ion collisions is studied at the next-to-leading-order (NLO) within the perturbative QCD, where the jet quenching effect in the QGP is incorporated with the effectively medium-modified $\\eta$ fragmentation functions using the higher-twist approach. We show that the theoretical simulations could give nice descriptions of PHENIX data on $\\eta$ meson in both $\\rm p+p$ and central $\\rm Au+Au$ collisions at the RHIC, and also provide numerical predictions of $\\eta$ spectra in central $\\rm Pb+Pb$ collisions with $\\sqrt{s_{NN}}=2.76$~TeV at the LHC. The ratios of $\\eta/\\pi^0$ in $\\rm p+p$ and in central $\\rm Au+Au$ collisions at $200$~GeV are found to overlap in a wide $p_T$ region, which matches well the measured ratio $\\eta / \\pi^0$ by PHENIX. We demonstrate that, at the asymptotic region when $p_{T} \\rightarrow \\infty$ the ratios of $\\eta/\\pi^{0}$ in both $\\rm Au+Au$ and $\\rm p+p$ are almost determined only by quark jets fragmentation and thus...

  8. Classical Gluon Radiation in Ultrarelativistic Nuclear Collisions: Space-Time Structure, Instabilities, and Thermalization

    E-Print Network [OSTI]

    S. G. Matinyan; B. Mueller; D. H. Rischke

    1997-08-28T23:59:59.000Z

    We investigate the space-time structure of the classical gluon field produced in an ultrarelativistic collision between color charges. The classical solution which was computed previously in a perturbative approach is shown to become unstable on account of the non-Abelian self-interaction neglected in the perturbative solution scheme. The time scale for growth of the instabilities is found to be of the order of the distance between the colliding color charges. We argue that these instabilities will eventually lead to thermalization of gluons produced in an ultrarelativistic collision between heavy nuclei. The rate of thermalization is estimated to be of order $g^2 \\mu$, where $g$ is the strong coupling constant and $\\mu^2$ the transverse color charge density of an ultrarelativistic nucleus.

  9. Energy dependence of space-time extent of pion source in nuclear collisions

    E-Print Network [OSTI]

    Okorokov, V A

    2015-01-01T23:59:59.000Z

    Energy dependence of space-time parameters of pion emission region at freeze-out is studied for collisions of various ions and for all experimentally available energies. The using of femtoscopic radii scaled on the averaged radius of colliding ions is suggested. This approach allows the expansion of the set of interaction types, in particular, on collisions of non-symmetrical ion beams which can be studied within the framework of common treatment. There is no sharp changing of femtoscopic parameter values with increasing of initial energy. Analytic functions suggested for smooth approximations of energy dependence of femtoscopic parameters demonstrate reasonable agreement with most of experimental data at $\\sqrt{s_{NN}} \\geq 5$ GeV. Estimations of some observables are obtained for energies of the LHC and FCC project.

  10. Energy dependence of space-time extent of pion source in nuclear collisions

    E-Print Network [OSTI]

    V. A. Okorokov

    2015-04-30T23:59:59.000Z

    Energy dependence of space-time parameters of pion emission region at freeze-out is studied for collisions of various ions and for all experimentally available energies. The using of femtoscopic radii scaled on the averaged radius of colliding ions is suggested. This approach allows the expansion of the set of interaction types, in particular, on collisions of non-symmetrical ion beams which can be studied within the framework of common treatment. There is no sharp changing of femtoscopic parameter values with increasing of initial energy. Analytic functions suggested for smooth approximations of energy dependence of femtoscopic parameters demonstrate reasonable agreement with most of experimental data at $\\sqrt{s_{NN}} \\geq 5$ GeV. Estimations of some observables are obtained for energies of the LHC and FCC project.

  11. De-Confinement and Clustering of Color Sources in Nuclear Collisions

    E-Print Network [OSTI]

    Braun, M A; Hirsch, A S; Pajares, C; Scharenberg, R P; Srivastava, B K

    2015-01-01T23:59:59.000Z

    A brief introduction of the relationship of string percolation to the Quantum Chromo Dynamics (QCD) phase diagram is presented. The behavior of the Polyakov loop close to the critical temperature is studied in terms of the color fields inside the clusters of overlapping strings, which are produced in high energy hadronic collisions. The non-Abelian nature of the color fields implies an enhancement of the transverse momentum and a suppression of the multiplicities relative to the non overlapping case. The prediction of this framework are compared with experimental results from the SPS, RHIC and LHC for $pp$ and AA collisions. Rapidity distributions, probability distributions of transverse momentum and multiplicities, Bose-Einstein correlations, elliptic flow and ridge structures are used to evaluate these comparison. The thermodynamical quantities, the temperature, and energy density derived from RHIC and LHC data and Color String Percolation Model (CSPM) are used to obtain the shear viscosity to entropy densi...

  12. Hybrid model calculations of direct photons in high-energy nuclear collisions

    E-Print Network [OSTI]

    Björn Bäuchle; Marcus Bleicher

    2010-03-04T23:59:59.000Z

    Direct photon emission in heavy-ion collisions is calculated within a relativistic micro+macro hybrid model and compared to the microscopic transport model UrQMD. In the hybrid approach, the high-density part of the evolution is replaced by an ideal 3-dimensional hydrodynamic calculation. This allows to examine the effects of viscosity and full local thermalization, in comparison of the transport model to the ideal fluid-dynamics. We study the origin of high-p_T photons as well as the impact of elementary high-sqrt(s) collisions. We further explore the contribution of different production channels and non-thermal radiation to the spectrum of direct photons. Detailed comparison to the measurements by the WA98-collaboration are also undertaken.

  13. Long range rapidity correlations and jet production in high energy nuclear collisions

    SciTech Connect (OSTI)

    STAR Collaboration; Abelev, Betty

    2010-07-05T23:59:59.000Z

    The STAR Collaboration at RHIC presents a systematic study of high transverse momentum charged di-hadron correlations at small azimuthal pair separation {Delta}{phi}, in d+Au and central Au+Au collisions at {radical}s{sub NN} = 200 GeV. Significant correlated yield for pairs with large longitudinal separation {Delta}{eta} is observed in central Au+Au, in contrast to d+Au collisions. The associated yield distribution in {Delta}{eta} x {delta}{phi} can be decomposed into a narrow jet-like peak at small angular separation which has a similar shape to that found in d+Au collisions, and a component which is narrow in {Delta}{phi} and depends only weakly on {Delta}{eta}, the 'ridge'. Using two systematically independent analyses, finite ridge yield is found to persist for trigger p{sub t} > 6 GeV/c, indicating that it is correlated with jet production. The transverse momentum spectrum of hadrons comprising the ridge is found to be similar to that of bulk particle production in the measured range (2 < p{sub t} < 4 GeV/c).

  14. Production of e+e- Pairs Accompanied by Nuclear Dissociation in Ultra-peripheral Heavy Ion Collisions

    SciTech Connect (OSTI)

    Adams, J.; Adler, C.; Aggarwal, M.M.; Ahammed, Z.; Allgower, C.; Amonett, J.; Anderson, B.D.; Anderson, M.; Arkhipkin, D.; Averichev, G.S.; Bai, Y.; Balewski, J.; Barannikova, O.; Barnby, L.S.; Baudot, J.; Bekele, S.; Belaga, V.V.; Bellwied, R.; Berger, J.; Bichsel, H.; Billmeier, A.; Bland, L.C.; Blyth, C.O.; Bonner, B.E.; Boucham, A.; Brandin, A.; Bravar, A.; Cadman, R.V.; Caines, H.; Calderon de la Barca Sanchez, M.; Cardenas, A.; Carroll, J.; Castillo, J.; Castro, M.; Cebra, D.; Chaloupka, P.; Chattopadhyay, S.; Chen, Y.; Chernenko, S.P.; Cherney, M.; Chikanian, A.; Choi, B.; Christie, W.; Coffin, J.P.; Cormier, T.M.; Corral, M.M.; Cramer, J.G.; Crawford, H.J.; Deng, W.S.; Derevschikov, A.A.; Didenko, L.; Dietel, T.; Draper, J.E.; Dunin, V.B.; Dunlop, J.C.; Eckardt, V.; Efimov, L.G.; Emelianov, V.; Engelage, J.; Eppley, G.; Erazmus, B.; Fachini, P.; Faine, V.; Faivre, J.; Fatemi, R.; Filimonov, K.; Finch, E.; Fisyak, Y.; Flierl, D.; Foley, K.J.; Fu, J.; Gagliardi, C.A.; Gagunashvili, N.; Gans, J.; Gaudichet, L.; Germain, M.; Geurts, F.; Ghazikhanian, V.; Grachov, O.; Grigoriev, V.; Guedon, M.; Guertin, S.M.; Gushin, E.; Hallman, T.J.; Hardtke, D.; Harris, J.W.; Heinz, M.; Henry, T.W.; Heppelmann, S.; Herston, T.; Hippolyte, B.; Hirsch, A.; Hjort, E.; Hoffmann, G.W.; Horsley, M.; Huang, H.Z.; Humanic, T.J.; Igo, G.; Ishihara, A.; Ivanshin, Yu.I.; Jacobs, P.; Jacobs, W.W.; Janik, M.; Johnson, I.; Jones, P.G.; Judd, E.G.; Kaneta, M.; Kaplan, M.; Keane, D.; Kiryluk, J.; Kisiel, A.; Klay, J.; Klein, S.R.; Klyachko, A.; Kollegger, T.; Konstantinov, A.; Kopytine, S.M.; Kotchenda, L.; Kovalenko, A.D.; Kramer, M.; Kravtsov, P.; Krueger, K.; Kuhn, C.; Kulikov, A.I.; Kunde, G.J.; Kunz, C.L.; Kutuev, R.K.; Kuznetsov, A.A.; Lamont, M.A.C.; Landgraf, J.M.; Lange, S.; Lansdell, C.P.; Lasiuk, B.; Laue, F.; Lauret, J.; Lebedev, A.; Lednicky, R.; Leontiev, V.M.; LeVine, M.J.; Li, Q.; Lindenbaum, S.J.; Lisa, M.A.; Liu, F.; Liu, L.; Liu, Z.; et al.

    2004-04-07T23:59:59.000Z

    We present the first data on e{sup +}e{sup -} pair production accompanied by nuclear breakup in ultra-peripheral gold-gold collisions at a center of mass energy of 200 GeV per nucleon pair. The nuclear breakup requirement selects events at small impact parameters, where higher-order corrections to the pair production cross section should be enhanced. We compare the pair kinematic distributions with two calculations: one based on the equivalent photon approximation, and the other using lowest-order quantum electrodynamics (QED); the latter includes the photon virtuality. The cross section, pair mass, rapidity and angular distributions are in good agreement with both calculations. The pair transverse momentum, p{sub T}, spectrum agrees with the QED calculation, but not with the equivalent photon approach. We set limits on higher-order contributions to the cross section. The e{sup +} and e{sup -} p{sub T} spectra are similar, with no evidence for interference effects due to higher-order diagrams.

  15. Heavy flavours in high-energy nuclear collisions: quenching, flow and correlations

    E-Print Network [OSTI]

    A. Beraudo; A. De Pace; M. Monteno; M. Nardi; F. Prino

    2014-12-01T23:59:59.000Z

    We present results for the quenching, elliptic flow and azimuthal correlations of heavy flavour particles in high-energy nucleus-nucleus collisions obtained through the POWLANG transport setup, developed in the past to study the propagation of heavy quarks in the Quark-Gluon Plasma and here extended to include a modeling of their hadronization in the presence of a medium. Hadronization is described as occurring via the fragmentation of strings with endpoints given by the heavy (anti-)quark Q(Qbar) and a thermal parton $qbar(q)$ from the medium. The flow of the light quarks is shown to affect significantly the R_AA} and v_2 of the final D mesons, leading to a better agreement with the experimental data.

  16. Observable measures of critical behavior in high-energy nuclear collisions

    E-Print Network [OSTI]

    Rudolph C. Hwa

    2000-07-19T23:59:59.000Z

    Critical behaviors of quark-hadron phase transition in high-energy heavy-ion collisions are investigated with the aim of identifying hadronic observables. The surface of the plasma cylinder is mapped onto a 2D lattice. The Ising model is used to simulate configurations corresponding to cross-over transitions in accordance to the findings of QCD lattice gauge theory. Hadrons are formed in clusters of all sizes. Various measures are examined to quantify the fluctuations of the cluster sizes and of the voids among the clusters. The canonical power-law behaviors near the critical temperature are found for appropriately chosen measures. Since the temperature is not directly observable, attention is given to the problem of finding observable measures. It is demonstrated that for the measures considered the dependence on the final-state randomization is weak. Thus the critical behavior of the measures proposed is likely to survive the scattering effect of the hadron gas in the final state.

  17. Jet quenching as a probe of the phases of QCD in relativistic nuclear collisions

    SciTech Connect (OSTI)

    Tarasov, Yu. A. [Russian Research Center 'Kurchatov Institute', RU-123182, Moscow (Russian Federation)

    2007-11-15T23:59:59.000Z

    We investigate the energy loss of gluon and quark jets in quark-gluon plasma produced in central Au+Au collisions at RHIC energy ({radical}(s{sub NN})=200 GeV). We use the effective quasiparticle model for investigation of physical characteristics of initial and mixed phases in expanding plasma. In the present work we calculate the quenching weight, i.e., the probability of medium-induced gluon radiation. We show that suppression of {pi}{sup 0} spectra is described correctly by quasiparticle model with increase of running coupling in the region of phase transition (at T{yields}T{sub c} from above) in agreement with recent lattice calculations and with PHENIX data. We show also that quasiparticle model with decrease of running coupling close to phase transition does not give correct description of this suppression.

  18. J/$?$ production and nuclear effects in p-Pb collisions at $\\sqrt{s_{\\rm NN}}=5.02$ TeV

    E-Print Network [OSTI]

    ALICE Collaboration

    2014-11-20T23:59:59.000Z

    Inclusive J/$\\psi$ production has been studied with the ALICE detector in p-Pb collisions at the nucleon-nucleon center of mass energy $\\sqrt{s_{\\rm NN}}$ = 5.02 TeV at the CERN LHC. The measurement is performed in the center of mass rapidity domains $2.03nuclear modification factor $R_{\\rm pPb}$ for the rapidities under study are presented. While at forward rapidity, corresponding to the proton direction, a suppression of the J/$\\psi$ yield with respect to binary-scaled pp collisions is observed, in the backward region no suppression is present. The ratio of the forward and backward yields is also measured differentially in rapidity and transverse momentum. Theoretical predictions based on nuclear shadowing, as well as on models including, in addition, a contribution from partonic energy loss, are in fair agreement with the experimental results.

  19. Nuclear modification factor in intermediate-energy heavy-ion collisions

    E-Print Network [OSTI]

    M. Lv; Y. G. Ma; G. Q. Zhang; J. H. Chen; D. Q. Fang

    2014-04-16T23:59:59.000Z

    The transverse momentum dependent nuclear modification factors (NMF), namely $R_{CP}$, is investigated for protons produced in Au + Au at 1$A$ GeV within the framework of the isospin-dependent quantum molecular dynamics (IQMD) model. It is found that the radial collective motion during the expansion stage affects the NMF at low transverse momentum a lot. By fitting the transverse mass spectra of protons with the distribution function from the Blast-Wave model, the magnitude of radial flow can be extracted. After removing the contribution from radial flow, the $R_{CP}$ can be regarded as a thermal one and is found to keep unitary at transverse momentum lower than 0.6 GeV/c and enhance at higher transverse momentum, which can be attributed to Cronin effect.

  20. Study of $J/?$ production and cold nuclear matter effects in $p$Pb collisions at $\\sqrt{s_{NN}}=5 \\mathrm{TeV}$

    E-Print Network [OSTI]

    LHCb collaboration; R. Aaij; B. Adeva; M. Adinolfi; C. Adrover; A. Affolder; Z. Ajaltouni; J. Albrecht; F. Alessio; M. Alexander; S. Ali; G. Alkhazov; P. Alvarez Cartelle; A. A. Alves Jr; S. Amato; S. Amerio; Y. Amhis; L. Anderlini; J. Anderson; R. Andreassen; J. E. Andrews; R. B. Appleby; O. Aquines Gutierrez; F. Archilli; A. Artamonov; M. Artuso; E. Aslanides; G. Auriemma; M. Baalouch; S. Bachmann; J. J. Back; A. Badalov; C. Baesso; V. Balagura; W. Baldini; R. J. Barlow; C. Barschel; S. Barsuk; W. Barter; Th. Bauer; A. Bay; J. Beddow; F. Bedeschi; I. Bediaga; S. Belogurov; K. Belous; I. Belyaev; E. Ben-Haim; G. Bencivenni; S. Benson; J. Benton; A. Berezhnoy; R. Bernet; M. -O. Bettler; M. van Beuzekom; A. Bien; S. Bifani; T. Bird; A. Bizzeti; P. M. Bj\\ornstad; T. Blake; F. Blanc; J. Blouw; S. Blusk; V. Bocci; A. Bondar; N. Bondar; W. Bonivento; S. Borghi; A. Borgia; T. J. V. Bowcock; E. Bowen; C. Bozzi; T. Brambach; J. van den Brand; J. Bressieux; D. Brett; M. Britsch; T. Britton; N. H. Brook; H. Brown; A. Bursche; G. Busetto; J. Buytaert; S. Cadeddu; O. Callot; M. Calvi; M. Calvo Gomez; A. Camboni; P. Campana; D. Campora Perez; A. Carbone; G. Carboni; R. Cardinale; A. Cardini; H. Carranza-Mejia; L. Carson; K. Carvalho Akiba; G. Casse; L. Cassina; L. Castillo Garcia; M. Cattaneo; Ch. Cauet; R. Cenci; M. Charles; Ph. Charpentier; S. -F. Cheung; N. Chiapolini; M. Chrzaszcz; K. Ciba; X. Cid Vidal; G. Ciezarek; P. E. L. Clarke; M. Clemencic; H. V. Cliff; J. Closier; C. Coca; V. Coco; J. Cogan; E. Cogneras; P. Collins; A. Comerma-Montells; A. Contu; A. Cook; M. Coombes; S. Coquereau; G. Corti; B. Couturier; G. A. Cowan; D. C. Craik; S. Cunliffe; R. Currie; C. D'Ambrosio; P. David; P. N. Y. David; A. Davis; I. De Bonis; K. De Bruyn; S. De Capua; M. De Cian; J. M. De Miranda; L. De Paula; W. De Silva; P. De Simone; D. Decamp; M. Deckenhoff; L. Del Buono; N. Déléage; D. Derkach; O. Deschamps; F. Dettori; A. Di Canto; H. Dijkstra; M. Dogaru; S. Donleavy; F. Dordei; A. Dosil Suárez; D. Dossett; A. Dovbnya; F. Dupertuis; P. Durante; R. Dzhelyadin; A. Dziurda; A. Dzyuba; S. Easo; U. Egede; V. Egorychev; S. Eidelman; D. van Eijk; S. Eisenhardt; U. Eitschberger; R. Ekelhof; L. Eklund; I. El Rifai; Ch. Elsasser; A. Falabella; C. Färber; C. Farinelli; S. Farry; D. Ferguson; V. Fernandez Albor; F. Ferreira Rodrigues; M. Ferro-Luzzi; S. Filippov; M. Fiore; C. Fitzpatrick; M. Fontana; F. Fontanelli; R. Forty; O. Francisco; M. Frank; C. Frei; M. Frosini; E. Furfaro; A. Gallas Torreira; D. Galli; M. Gandelman; P. Gandini; Y. Gao; J. Garofoli; P. Garosi; J. Garra Tico; L. Garrido; C. Gaspar; R. Gauld; E. Gersabeck; M. Gersabeck; T. Gershon; Ph. Ghez; V. Gibson; L. Giubega; V. V. Gligorov; C. Göbel; D. Golubkov; A. Golutvin; A. Gomes; P. Gorbounov; H. Gordon; M. Grabalosa Gándara; R. Graciani Diaz; L. A. Granado Cardoso; E. Graugés; G. Graziani; A. Grecu; E. Greening; S. Gregson; P. Griffith; O. Grünberg; B. Gui; E. Gushchin; Yu. Guz; T. Gys; C. Hadjivasiliou; G. Haefeli; C. Haen; S. C. Haines; S. Hall; B. Hamilton; T. Hampson; S. Hansmann-Menzemer; N. Harnew; S. T. Harnew; J. Harrison; T. Hartmann; J. He; T. Head; V. Heijne; K. Hennessy; P. Henrard; J. A. Hernando Morata; E. van Herwijnen; M. Heß; A. Hicheur; E. Hicks; D. Hill; M. Hoballah; C. Hombach; W. Hulsbergen; P. Hunt; T. Huse; N. Hussain; D. Hutchcroft; D. Hynds; V. Iakovenko; M. Idzik; P. Ilten; R. Jacobsson; A. Jaeger; E. Jans; P. Jaton; A. Jawahery; F. Jing; M. John; D. Johnson; C. R. Jones; C. Joram; B. Jost; M. Kaballo; S. Kandybei; W. Kanso; M. Karacson; T. M. Karbach; I. R. Kenyon; T. Ketel; B. Khanji; O. Kochebina; I. Komarov; R. F. Koopman; P. Koppenburg; M. Korolev; A. Kozlinskiy; L. Kravchuk; K. Kreplin; M. Kreps; G. Krocker; P. Krokovny; F. Kruse; M. Kucharczyk; V. Kudryavtsev; K. Kurek; T. Kvaratskheliya; V. N. La Thi; D. Lacarrere; G. Lafferty; A. Lai; D. Lambert; R. W. Lambert; E. Lanciotti; G. Lanfranchi; C. Langenbruch; T. Latham; C. Lazzeroni; R. Le Gac; J. van Leerdam; J. -P. Lees; R. Lefčvre; A. Leflat; J. Lefrançois; S. Leo; O. Leroy; T. Lesiak; B. Leverington; Y. Li; L. Li Gioi; M. Liles; R. Lindner; C. Linn; B. Liu; G. Liu; S. Lohn; I. Longstaff; J. H. Lopes; N. Lopez-March; H. Lu; D. Lucchesi; J. Luisier; H. Luo; O. Lupton; F. Machefert; I. V. Machikhiliyan; F. Maciuc; O. Maev; S. Malde; G. Manca; G. Mancinelli; J. Maratas; U. Marconi; P. Marino; R. Märki; J. Marks; G. Martellotti; A. Martens; A. Martín Sánchez; M. Martinelli; D. Martinez Santos; D. Martins Tostes; A. Martynov; A. Massafferri; R. Matev; Z. Mathe; C. Matteuzzi; E. Maurice; A. Mazurov; J. McCarthy; A. McNab; R. McNulty; B. McSkelly; B. Meadows; F. Meier; M. Meissner; M. Merk; D. A. Milanes; M. -N. Minard; J. Molina Rodriguez; S. Monteil; D. Moran; P. Morawski; A. Mordŕ; M. J. Morello; R. Mountain; I. Mous; F. Muheim; K. Müller

    2014-03-25T23:59:59.000Z

    The production of $J/\\psi$ mesons with rapidity $1.5collisions at a nucleon-nucleon centre-of-mass energy $\\sqrt{s_{NN}}=5 \\mathrm{TeV}$. The analysis is based on a data sample corresponding to an integrated luminosity of about $1.6 \\mathrm{nb}^{-1}$. For the first time the nuclear modification factor and forward-backward production ratio are determined separately for prompt $J/\\psi$ mesons and $J/\\psi$ from $b$-hadron decays. Clear suppression of prompt $J/\\psi$ production with respect to proton-proton collisions at large rapidity is observed, while the production of $J/\\psi$ from $b$-hadron decays is less suppressed. These results show good agreement with available theoretical predictions. The measurement shows that cold nuclear matter effects are important for interpretations of the related quark-gluon plasma signatures in heavy-ion collisions.

  1. Two-Photon Interactions with Nuclear Breakup in Relativistic Heavy Ion Collisions

    SciTech Connect (OSTI)

    Baltz, Anthony J.; Gorbunov, Yuri; R Klein, Spencer; Nystrand, Joakim

    2010-07-07T23:59:59.000Z

    Highly charged relativistic heavy ions have high cross-sections for two-photon interactions. The photon flux is high enough that two-photon interactions may be accompanied by additional photonuclear interactions. Except for the shared impact parameter, these interactions are independent. Additional interactions like mutual Coulomb excitation are of experimental interest, since the neutrons from the nuclear dissociation provide a simple, relatively unbiased trigger. We calculate the cross sections, rapidity, mass and transverse momentum (p{sub T}) distributions for exclusive {gamma}{gamma} production of mesons and lepton pairs, and for {gamma}{gamma} reactions accompanied by mutual Coulomb dissociation. The cross-sections for {gamma}{gamma} interactions accompanied by multiple neutron emission (XnXn) and single neutron emission (1n1n) are about 1/10 and 1/100 of that for the unaccompanied {gamma}{gamma} interactions. We discuss the accuracy with which these cross-sections may be calculated. The typical p{sub T} of {gamma}{gamma} final states is several times smaller than for comparable coherent photonuclear interactions, so p{sub T} may be an effective tool for separating the two classes of interactions.

  2. Nuclear stopping and rapidity loss in Au+Au collisions at sNN =62.4 GeV

    E-Print Network [OSTI]

    M. Smoluchowski Inst. of Physics, Jagiellonian University, Krakow, Poland eNew York University, New York, USA, f energy are discussed. PACS numbers: 25.75 Dw. In collisions between gold nuclei at the top en- ergy ( s. The energy required for producing these parti- cles comes from the kinetic energy lost by the baryons

  3. Particle spectra and HBT radii for simulated central nuclear collisions of C+C, Al+Al, Cu+Cu, Au+Au, and Pb+Pb from Sqrt(s)=62.4-2760 GeV

    E-Print Network [OSTI]

    M. Habich; J. L. Nagle; P. Romatschke

    2015-02-23T23:59:59.000Z

    We study the temperature profile, pion spectra and HBT radii in central symmetric and boost-invariant nuclear collisions using a super hybrid model for heavy-ion collisions (SONIC) combining pre-equilibrium flow with viscous hydrodynamics and late-stage hadronic rescatterings. In particular, we simulate Pb+Pb collisions at Sqrt(s)=2.76 TeV, Au+Au, Cu+Cu, Al+Al, and C+C collisions at Sqrt(s)=200 GeV and Au+Au, Cu+Cu collisions at Sqrt(s)=62.4 GeV. We find that SONIC provides a good match to the pion spectra and HBT radii for all collision systems and energies, confirming earlier work that a combination of pre-equilibrium flow, viscosity and QCD equation of state can resolve the so-called HBT puzzle. For reference, we also show p+p collisions at Sqrt(s)=7 TeV. We make tabulated data for the 2+1 dimensional temperature evolution of all systems publicly available for the use in future jet energy loss or similar studies.

  4. Study of $?$ production and cold nuclear matter effects in pPb collisions at $\\sqrt{s_{NN}}=5~\\mathrm{TeV}$

    E-Print Network [OSTI]

    LHCb collaboration; R. Aaij; B. Adeva; M. Adinolfi; A. Affolder; Z. Ajaltouni; J. Albrecht; F. Alessio; M. Alexander; S. Ali; G. Alkhazov; P. Alvarez Cartelle; A. A. Alves Jr; S. Amato; S. Amerio; Y. Amhis; L. An; L. Anderlini; J. Anderson; R. Andreassen; M. Andreotti; J. E. Andrews; R. B. Appleby; O. Aquines Gutierrez; F. Archilli; A. Artamonov; M. Artuso; E. Aslanides; G. Auriemma; M. Baalouch; S. Bachmann; J. J. Back; A. Badalov; V. Balagura; W. Baldini; R. J. Barlow; C. Barschel; S. Barsuk; W. Barter; V. Batozskaya; A. Bay; L. Beaucourt; J. Beddow; F. Bedeschi; I. Bediaga; S. Belogurov; K. Belous; I. Belyaev; E. Ben-Haim; G. Bencivenni; S. Benson; J. Benton; A. Berezhnoy; R. Bernet; M. -O. Bettler; M. van Beuzekom; A. Bien; S. Bifani; T. Bird; A. Bizzeti; P. M. Bjřrnstad; T. Blake; F. Blanc; J. Blouw; S. Blusk; V. Bocci; A. Bondar; N. Bondar; W. Bonivento; S. Borghi; A. Borgia; M. Borsato; T. J. V. Bowcock; E. Bowen; C. Bozzi; T. Brambach; J. van den Brand; J. Bressieux; D. Brett; M. Britsch; T. Britton; J. Brodzicka; N. H. Brook; H. Brown; A. Bursche; G. Busetto; J. Buytaert; S. Cadeddu; R. Calabrese; M. Calvi; M. Calvo Gomez; A. Camboni; P. Campana; D. Campora Perez; A. Carbone; G. Carboni; R. Cardinale; A. Cardini; H. Carranza-Mejia; L. Carson; K. Carvalho Akiba; G. Casse; L. Cassina; L. Castillo Garcia; M. Cattaneo; Ch. Cauet; R. Cenci; M. Charles; Ph. Charpentier; S. Chen; S. -F. Cheung; N. Chiapolini; M. Chrzaszcz; K. Ciba; X. Cid Vidal; G. Ciezarek; P. E. L. Clarke; M. Clemencic; H. V. Cliff; J. Closier; V. Coco; J. Cogan; E. Cogneras; P. Collins; A. Comerma-Montells; A. Contu; A. Cook; M. Coombes; S. Coquereau; G. Corti; M. Corvo; I. Counts; B. Couturier; G. A. Cowan; D. C. Craik; M. Cruz Torres; S. Cunliffe; R. Currie; C. D'Ambrosio; J. Dalseno; P. David; P. N. Y. David; A. Davis; K. De Bruyn; S. De Capua; M. De Cian; J. M. De Miranda; L. De Paula; W. De Silva; P. De Simone; D. Decamp; M. Deckenhoff; L. Del Buono; N. Déléage; D. Derkach; O. Deschamps; F. Dettori; A. Di Canto; H. Dijkstra; S. Donleavy; F. Dordei; M. Dorigo; A. Dosil Suárez; D. Dossett; A. Dovbnya; G. Dujany; F. Dupertuis; P. Durante; R. Dzhelyadin; A. Dziurda; A. Dzyuba; S. Easo; U. Egede; V. Egorychev; S. Eidelman; S. Eisenhardt; U. Eitschberger; R. Ekelhof; L. Eklund; I. El Rifai; Ch. Elsasser; S. Ely; S. Esen; T. Evans; A. Falabella; C. Färber; C. Farinelli; N. Farley; S. Farry; D. Ferguson; V. Fernandez Albor; F. Ferreira Rodrigues; M. Ferro-Luzzi; S. Filippov; M. Fiore; M. Fiorini; M. Firlej; C. Fitzpatrick; T. Fiutowski; M. Fontana; F. Fontanelli; R. Forty; O. Francisco; M. Frank; C. Frei; M. Frosini; J. Fu; E. Furfaro; A. Gallas Torreira; D. Galli; S. Gallorini; S. Gambetta; M. Gandelman; P. Gandini; Y. Gao; J. Garofoli; J. Garra Tico; L. Garrido; C. Gaspar; R. Gauld; L. Gavardi; E. Gersabeck; M. Gersabeck; T. Gershon; Ph. Ghez; A. Gianelle; S. Giani'; V. Gibson; L. Giubega; V. V. Gligorov; C. Göbel; D. Golubkov; A. Golutvin; A. Gomes; H. Gordon; C. Gotti; M. Grabalosa Gándara; R. Graciani Diaz; L. A. Granado Cardoso; E. Graugés; G. Graziani; A. Grecu; E. Greening; S. Gregson; P. Griffith; L. Grillo; O. Grünberg; B. Gui; E. Gushchin; Yu. Guz; T. Gys; C. Hadjivasiliou; G. Haefeli; C. Haen; S. C. Haines; S. Hall; B. Hamilton; T. Hampson; X. Han; S. Hansmann-Menzemer; N. Harnew; S. T. Harnew; J. Harrison; T. Hartmann; J. He; T. Head; V. Heijne; K. Hennessy; P. Henrard; L. Henry; J. A. Hernando Morata; E. van Herwijnen; M. Heß; A. Hicheur; D. Hill; M. Hoballah; C. Hombach; W. Hulsbergen; P. Hunt; N. Hussain; D. Hutchcroft; D. Hynds; M. Idzik; P. Ilten; R. Jacobsson; A. Jaeger; J. Jalocha; E. Jans; P. Jaton; A. Jawahery; M. Jezabek; F. Jing; M. John; D. Johnson; C. R. Jones; C. Joram; B. Jost; N. Jurik; M. Kaballo; S. Kandybei; W. Kanso; M. Karacson; T. M. Karbach; M. Kelsey; I. R. Kenyon; T. Ketel; B. Khanji; C. Khurewathanakul; S. Klaver; O. Kochebina; M. Kolpin; I. Komarov; R. F. Koopman; P. Koppenburg; M. Korolev; A. Kozlinskiy; L. Kravchuk; K. Kreplin; M. Kreps; G. Krocker; P. Krokovny; F. Kruse; M. Kucharczyk; V. Kudryavtsev; K. Kurek; T. Kvaratskheliya; V. N. La Thi; D. Lacarrere; G. Lafferty; A. Lai; D. Lambert; R. W. Lambert; E. Lanciotti; G. Lanfranchi; C. Langenbruch; B. Langhans; T. Latham; C. Lazzeroni; R. Le Gac; J. van Leerdam; J. -P. Lees; R. Lefčvre; A. Leflat; J. Lefrançois; S. Leo; O. Leroy; T. Lesiak; B. Leverington; Y. Li; M. Liles; R. Lindner; C. Linn; F. Lionetto; B. Liu; G. Liu; S. Lohn; I. Longstaff; J. H. Lopes; N. Lopez-March; P. Lowdon; H. Lu; D. Lucchesi; H. Luo; A. Lupato; E. Luppi; O. Lupton; F. Machefert; I. V. Machikhiliyan; F. Maciuc; O. Maev; S. Malde; G. Manca; G. Mancinelli; M. Manzali; J. Maratas; J. F. Marchand; U. Marconi; C. Marin Benito; P. Marino; R. Märki; J. Marks; G. Martellotti; A. Martens; A. Martín Sánchez; M. Martinelli

    2014-10-15T23:59:59.000Z

    Production of $\\Upsilon$ mesons in proton-lead collisions at a nucleon-nucleon centre-of-mass energy $\\sqrt{s_{NN}}=5 \\mathrm{TeV}$ is studied with the LHCb detector. The analysis is based on a data sample corresponding to an integrated luminosity of $1.6 \\mathrm{nb}^{-1}$. The $\\Upsilon$ mesons of transverse momenta up to $15 \\mathrm{GeV}/c$ are reconstructed in the dimuon decay mode. The rapidity coverage in the centre-of-mass system is $1.5nuclear modification factor for $\\Upsilon(1S)$ mesons are determined. The data are compatible with the predictions for a suppression of $\\Upsilon(1S)$ production with respect to proton-proton collisions in the forward region, and an enhancement in the backward region. The suppression is found to be smaller than in the case of prompt $J/\\psi$ mesons.

  5. Confronting fluctuations of conserved charges in central nuclear collisions at the LHC with predictions from Lattice QCD

    E-Print Network [OSTI]

    Peter Braun-Munzinger; Alexander Kalweit; Krzysztof Redlich; Johanna Stachel

    2015-05-06T23:59:59.000Z

    We construct net baryon number and strangeness susceptibilities as well as correlations between electric charge and strangeness from experimental data of the ALICE Collaboration at the CERN LHC. The data were taken in Pb-Pb collisions at $\\sqrt{s_{NN}}$=2.76 TeV. The resulting fluctuations and correlations are consistent with Lattice QCD results at the chiral crossover pseudocritical temperature $T_c\\simeq 155$ MeV. This agreement lends strong support to the assumption that the fireball created in these collisions is of thermal origin and exhibits characteristic properties expected in QCD at the transition from the quark gluon plasma to the hadronic phase. The volume of the fireball for one unit of rapidity at $T_c$ is found to exceed 4000 fm$^3$. A detailed discussion on uncertainties in the temperature and volume of the fireball is presented. The results are linked to pion interferometry measurements and predictions from percolation theory.

  6. $J/?$ suppression in Pb+Pb collisions, a conventional description

    E-Print Network [OSTI]

    A. K. Chaudhuri

    2001-09-17T23:59:59.000Z

    We have analyzed the latest NA50 data on $J/\\psi$ suppression in Pb + Pb collisions. $J/\\psi$ production is assumed to be a two step process, (i) formation of $c\\bar{c}$ pair, which is accurately calculable in QCD and (ii) formation of $J/\\psi$ meson from the $c\\bar{c}$ pair, which can be conveniently parameterized. In a pA/AA collision, the as the $c\\bar{c}$ pair pass through the nuclear medium, it gain relative square momentum at the rate of $\\epsilon^2$ per unit path length. As a result, some of the $c\\bar{c}$ pairs can gain enough momentum to cross the threshold to become an open charm meson, leading to suppression in pA/AA collisions. The parameters of the model were fixed from experimental data on the total $J/\\psi$ cross section as a function of effective nuclear length. The model without any free parameter, give excellent description of NA50 data on $E_T$ dependence of $J/\\psi$ to Drell-Yan ratio. The model was applied to predict the $E_T$ dependence of $J/\\psi$ at RHIC energy. Much larger suppression of $J/\\psi$, in agreement with other model calculations are predicted.

  7. Jet quenching and neutral pion production in Au+Au collisions at RHIC

    E-Print Network [OSTI]

    A. K. Chaudhuri

    2005-06-01T23:59:59.000Z

    In the jet quenching model, we have analysed the PHENIX data on nuclear modification factor of $\\pi^0$, in Au+Au collisions at $\\sqrt{s}$=200 GeV, and extracted the initial gluon density of the medium produced. In jet quenching, partons lose energy in the medium, depending on the medium density as well as on the in-medium path length. Systematic analysis indicate that in most central (0-10% centrality) collisions, medium density is very large $dN_g/dy \\sim$ 2150. Medium density decreases exponentially as the collision centrality decreases and in very peripheral (70-92% centrality) collisions, $dN_g/dy \\sim$ 3. Initial energy density of the medium also decreases smoothly from $\\epsilon_0 \\sim$ 20 $GeV/fm^3$ in most central collisions to $\\epsilon_0 \\sim$ 3 $GeV/fm^3$ in most peripheral collisions. Very large $dN_g/dy$ or $\\epsilon_0$ indicate very dense matter formation in central Au+Au collisions.

  8. A hybrid model for studying nuclear multifragmentation around Fermi energy domain: Case for central collision of Xe on Sn

    E-Print Network [OSTI]

    Mallik, S; Gupta, S Das

    2015-01-01T23:59:59.000Z

    Experimental data for central collisions of $^{129}$Xe on $^{119}$Sn at beam energies of (a) 32 MeV/nucleon, (b) 39 MeV/nucleon, (c) 45 MeV/nucleon and (d) 50 MeV/nucleon are compared with results calculated using a hybrid model. We use a transport model (BUU) to obtain the excitation energy per nucleon in the center of mass of the multifragmenting system. The canonical thermodynamic model is then used to determine the temperature which would lead to this excitation energy. With this temperature we use the canonical thermodynamic model to calculate various experimental data such as multiplicities of different composites, probability distribution of the largest cluster etc. Agreement with data establishes the validity of the model.

  9. A hybrid model for studying nuclear multifragmentation around Fermi energy domain: Case for central collision of Xe on Sn

    E-Print Network [OSTI]

    S. Mallik; G. Chaudhuri; S. Das Gupta

    2015-03-17T23:59:59.000Z

    Experimental data for central collisions of $^{129}$Xe on $^{119}$Sn at beam energies of (a) 32 MeV/nucleon, (b) 39 MeV/nucleon, (c) 45 MeV/nucleon and (d) 50 MeV/nucleon are compared with results calculated using a hybrid model. We use a transport model (BUU) to obtain the excitation energy per nucleon in the center of mass of the multifragmenting system. The canonical thermodynamic model is then used to determine the temperature which would lead to this excitation energy. With this temperature we use the canonical thermodynamic model to calculate various experimental data such as multiplicities of different composites, probability distribution of the largest cluster etc. Agreement with data establishes the validity of the model.

  10. Rapidity and transverse-momentum dependence of the inclusive J/psi nuclear modification factor in p-Pb collisions at ?s_NN = 5.02 TeV

    E-Print Network [OSTI]

    The ALICE Collaboration, CERN; The ALICE collaboration

    2015-01-01T23:59:59.000Z

    The ALICE Collaboration has studied the transverse-momentum (pT) dependence of the inclusive J/psi production in p-Pb collisions at ?s_NN = 5.02 TeV, in three center-of-mass rapidity (y_cms) regions, down to zero pT. Results in the forward and backward rapidity ranges (2.03 nuclear modification factor are presented for each of the rapidity intervals, as well as the J/psi mean pT values. Forward and mid-rapidity results show a suppression of the J/psi yield, with respect to pp collisions, which decreases with increasing pT. At backward rapidity no significant J/psi suppression is observed. Theoretical models including a combination of cold nuclear matter effects such as shadowing and partonic energy loss, are in fair agreement...

  11. Nuclear Science Division Annual Report 1984-85

    E-Print Network [OSTI]

    Mahoney Editor, Jeannette

    2010-01-01T23:59:59.000Z

    M. Xcssi. and W. Wolf. Nuclear-Reaction-Time Studies of U +K° Produced in Relativistic Nuclear Collisions Phys. Lett.Momentum Distributions of Nuclear Fragments in im Collisions

  12. NUCLEAR CHEMISTRY DIV. ANNUAL REPORT 1980-81

    E-Print Network [OSTI]

    Cerny, J.

    2010-01-01T23:59:59.000Z

    Polarization Phenomena in Nuclear Physics-1980, AIP Conf.Barrett and D.F. Jackson, Nuclear Sizes and Structure, (K Production in Relativistic Nuclear Collisions A. Shor, K.

  13. Rapidity and transverse-momentum dependence of the inclusive J/$\\mathbf?$ nuclear modification factor in p-Pb collisions at $\\mathbf{\\sqrt{\\textit{s}_{NN}}}=5.02$ TeV

    E-Print Network [OSTI]

    ALICE Collaboration

    2015-03-24T23:59:59.000Z

    We have studied the transverse-momentum ($p_{\\rm T}$) dependence of the inclusive J/$\\psi$ production in p-Pb collisions at $\\sqrt{s_{\\rm NN}} = 5.02$ TeV, in three center-of-mass rapidity ($y_{\\rm cms}$) regions, down to zero $p_{\\rm T}$. Results in the forward and backward rapidity ranges ($2.03 nuclear modification factor are presented for each of the rapidity intervals, as well as the J/$\\psi$ mean $p_{\\rm T}$ values. Forward and mid-rapidity results show a suppression of the J/$\\psi$ yield, with respect to pp collisions, which decreases with increasing $p_{\\rm T}$. At backward rapidity no significant J/$\\psi$ suppression is observed. Theoretical models including a combination of cold nuclear matter effects such as shadowing and partonic energy loss, are in fair agreement with the data, except at forward rapidity and low transverse momentum. The implications of the p-Pb results for the evaluation of cold nuclear matter effects on J/$\\psi$ production in Pb-Pb collisions are also discussed.

  14. Strangeness production from pp collisions

    E-Print Network [OSTI]

    Bing-Song Zou; Ju-Jun Xie

    2009-10-23T23:59:59.000Z

    The study of the strangeness production from pp collisions plays important roles in two aspects: exploring the properties of baryon resonances involved and understanding the strangeness production from heavy ion collisions to explore the properties of high energy and high density nuclear matter. Here we review our recent studies on several most important channels for the strangeness production from pp collisions. The previously ignored contributions from Delta*(1620) and N*(1535) resonances are found to play dominant role for the pp --> n K+ Sigma+, pp --> pK+ Lambda and pp --> pp phi reactions near-thresholds. These contributions should be included for further studies on the strangeness production from both pp collisions and heavy ion collisions.

  15. Observation of $D^0$ meson nuclear modifications in Au+Au collisions at $\\sqrt{s_{_{\\mathrm{NN}}}}$ = 200 GeV

    E-Print Network [OSTI]

    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. Videbćk; 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

    2014-09-09T23:59:59.000Z

    We report the first measurement of charmed-hadron ($D^0$) production via the hadronic decay channel ($D^0\\rightarrow K^- + \\pi^+$) in Au+Au collisions at $\\sqrt{s_{_{\\mathrm{NN}}}}$ = 200\\,GeV with the STAR experiment. The charm production cross-section per nucleon-nucleon collision at mid-rapidity scales with the number of binary collisions, $N_{bin}$, from $p$+$p$ to central Au+Au collisions. The $D^0$ meson yields in central Au+Au collisions are strongly suppressed compared to those in $p$+$p$ scaled by $N_{bin}$, for transverse momenta $p_{T}>3$ GeV/$c$, demonstrating significant energy loss of charm quarks in the hot and dense medium. An enhancement at intermediate $p_{T}$ is also observed. Model calculations including strong charm-medium interactions and coalescence hadronization describe our measurements.

  16. Atomic Collision and Ionization Effects in Oxides. | EMSL

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

    is a challenging area for scientific research. Citation: Zhang Y, IT Bae, and WJ Weber.2008."Atomic Collision and Ionization Effects in Oxides."Nuclear Instruments and...

  17. Simulation of collision cascades and thermal spikes in ceramics...

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

    formed and mainly isolated Frenkel pairs are produced. Citation: Devanathan R, and WJ Weber.2010."Simulation of collision cascades and thermal spikes in ceramics."Nuclear...

  18. atomic collision cascades: Topics by E-print Network

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

    implications. Leszek Motyka; Mariusz Sadzikowski 1999-12-04 2 Parton Cascades in High Energy Nuclear Collisions Nuclear Theory (arXiv) Summary: This is a review of the parton...

  19. Jets in relativistic heavy ion collisions

    SciTech Connect (OSTI)

    Wang, Xin-Nian; Gyulassy, M.

    1990-09-01T23:59:59.000Z

    Several aspects of hard and semihard QCD jets in relativistic heavy ion collisions are discussed, including multiproduction of minijets and the interaction of a jet with dense nuclear matter. The reduction of jet quenching effect in deconfined phase of nuclear matter is speculated to provide a signature of the formation of quark gluon plasma. HIJING Monte Carlo program which can simulate events of jets production and quenching in heavy ion collisions is briefly described. 35 refs., 13 figs.

  20. Jet Production in p-Pb Collisions

    E-Print Network [OSTI]

    Megan Connors; for the ALICE Collaboration

    2014-09-19T23:59:59.000Z

    One of the major results from the study of high energy heavy ion collisions is the observation of jet quenching. The suppression of the number of jets observed in heavy ion collisions relative to pp collisions at the same energy scaled by the number of binary collisions, is attributed to partonic energy loss in the quark gluon plasma (QGP). However, cold nuclear matter effects due to the presence of a nucleus in the initial state could also influence this measurement. To disentangle these effects p-Pb collisions are studied, where QGP formation is not expected to occur and only cold nuclear matter effects are present. In addition to being an important baseline for understanding jet quenching, jets in p-Pb collisions may also be used to provide constraints on the nuclear parton distribution functions. Fully reconstructed jets measured using the ALICE tracking system and electro-magnetic calorimeter in p-Pb collisions at $\\sqrt{s_{NN}}=5.02$ TeV are reported. In addition to the spectra, studies of the jet fragmentation behavior in p-Pb collisions are also presented.

  1. Editorial: Redefining Length

    SciTech Connect (OSTI)

    Sprouse, Gene D. [American Physical Society (United States)

    2011-07-15T23:59:59.000Z

    Technological changes have moved publishing to electronic-first publication where the print version has been relegated to simply another display mode. Distribution in HTML and EPUB formats, for example, changes the reading environment and reduces the need for strict pagination. Therefore, in an effort to streamline the calculation of length, the APS journals will no longer use the printed page as the determining factor for length. Instead the journals will now use word counts (or word equivalents for tables, figures, and equations) to establish length; for details please see http://publish.aps.org/authors/length-guide. The title, byline, abstract, acknowledgment, and references will not be included in these counts allowing authors the freedom to appropriately credit coworkers, funding sources, and the previous literature, bringing all relevant references to the attention of readers. This new method for determining length will be easier for authors to calculate in advance, and lead to fewer length-associated revisions in proof, yet still retain the quality of concise communication that is a virtue of short papers.

  2. atomic scattering length: Topics by E-print Network

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

    15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Atomic-Molecular Condensates with Large Positive Scattering Length Nuclear Theory (arXiv) Summary: We show that...

  3. Rapidity and transverse-momentum dependence of the inclusive J/$\\mathbf{\\psi}$ nuclear modification factor in p-Pb collisions at $\\mathbf{\\sqrt{\\textit{s}_{NN}}}=5.02$ TeV

    E-Print Network [OSTI]

    Adam, Jaroslav; Aggarwal, Madan Mohan; Aglieri Rinella, Gianluca; Agnello, Michelangelo; Agrawal, Neelima; Ahammed, Zubayer; Ahmed, Ijaz; Ahn, Sang Un; Aimo, Ilaria; Aiola, Salvatore; Ajaz, Muhammad; Akindinov, Alexander; Alam, Sk Noor; Aleksandrov, Dmitry; Alessandro, Bruno; Alexandre, Didier; Alfaro Molina, Jose Ruben; Alici, Andrea; Alkin, Anton; Alme, Johan; Alt, Torsten; Altinpinar, Sedat; Altsybeev, Igor; Alves Garcia Prado, Caio; Andrei, Cristian; Andronic, Anton; Anguelov, Venelin; Anielski, Jonas; Anticic, Tome; Antinori, Federico; Antonioli, Pietro; Aphecetche, Laurent Bernard; Appelshaeuser, Harald; Arcelli, Silvia; Armesto Perez, Nestor; Arnaldi, Roberta; Aronsson, Tomas; Arsene, Ionut Cristian; Arslandok, Mesut; Augustinus, Andre; Averbeck, Ralf Peter; Azmi, Mohd Danish; Bach, Matthias Jakob; Badala, Angela; Baek, Yong Wook; Bagnasco, Stefano; Bailhache, Raphaelle Marie; Bala, Renu; Baldisseri, Alberto; Baltasar Dos Santos Pedrosa, Fernando; Baral, Rama Chandra; Barbano, Anastasia Maria; Barbera, Roberto; Barile, Francesco; Barnafoldi, Gergely Gabor; Barnby, Lee Stuart; Ramillien Barret, Valerie; Bartalini, Paolo; Bartke, Jerzy Gustaw; Bartsch, Esther; Basile, Maurizio; Bastid, Nicole; Basu, Sumit; Bathen, Bastian; Batigne, Guillaume; Batista Camejo, Arianna; Batyunya, Boris; Batzing, Paul Christoph; Bearden, Ian Gardner; Beck, Hans; Bedda, Cristina; Behera, Nirbhay Kumar; Belikov, Iouri; Bellini, Francesca; Bello Martinez, Hector; Bellwied, Rene; Belmont Iii, Ronald John; Belmont Moreno, Ernesto; Belyaev, Vladimir; Bencedi, Gyula; Beole, Stefania; Berceanu, Ionela; Bercuci, Alexandru; Berdnikov, Yaroslav; Berenyi, Daniel; Bertens, Redmer Alexander; Berzano, Dario; Betev, Latchezar; Bhasin, Anju; Bhat, Inayat Rasool; Bhati, Ashok Kumar; Bhattacharjee, Buddhadeb; Bhom, Jihyun; Bianchi, Livio; Bianchi, Nicola; Bianchin, Chiara; Bielcik, Jaroslav; Bielcikova, Jana; Bilandzic, Ante; Biswas, Saikat; Bjelogrlic, Sandro; Blanco, Fernando; Blau, Dmitry; Blume, Christoph; Bock, Friederike; Bogdanov, Alexey; Boggild, Hans; Boldizsar, Laszlo; Bombara, Marek; Book, Julian Heinz; Borel, Herve; Borissov, Alexander; Borri, Marcello; Bossu, Francesco; Botje, Michiel; Botta, Elena; Boettger, Stefan; Braun-Munzinger, Peter; Bregant, Marco; Breitner, Timo Gunther; Broker, Theo Alexander; Browning, Tyler Allen; Broz, Michal; Brucken, Erik Jens; Bruna, Elena; Bruno, Giuseppe Eugenio; Budnikov, Dmitry; Buesching, Henner; Bufalino, Stefania; Buncic, Predrag; Busch, Oliver; Buthelezi, Edith Zinhle; Buxton, Jesse Thomas; Caffarri, Davide; Cai, Xu; Caines, Helen Louise; Calero Diaz, Liliet; Caliva, Alberto; Calvo Villar, Ernesto; Camerini, Paolo; Carena, Francesco; Carena, Wisla; Castillo Castellanos, Javier Ernesto; Castro, Andrew John; Casula, Ester Anna Rita; Cavicchioli, Costanza; Ceballos Sanchez, Cesar; Cepila, Jan; Cerello, Piergiorgio; Chang, Beomsu; Chapeland, Sylvain; Chartier, Marielle; Charvet, Jean-Luc Fernand; Chattopadhyay, Subhasis; Chattopadhyay, Sukalyan; Chelnokov, Volodymyr; Cherney, Michael Gerard; Cheshkov, Cvetan Valeriev; Cheynis, Brigitte; Chibante Barroso, Vasco Miguel; Dobrigkeit Chinellato, David; Chochula, Peter; Choi, Kyungeon; Chojnacki, Marek; Choudhury, Subikash; Christakoglou, Panagiotis; Christensen, Christian Holm; Christiansen, Peter; Chujo, Tatsuya; Chung, Suh-Urk; Cicalo, Corrado; Cifarelli, Luisa; Cindolo, Federico; Cleymans, Jean Willy Andre; Colamaria, Fabio Filippo; Colella, Domenico; Collu, Alberto; Colocci, Manuel; Conesa Balbastre, Gustavo; Conesa Del Valle, Zaida; Connors, Megan Elizabeth; Contreras Nuno, Jesus Guillermo; Cormier, Thomas Michael; Corrales Morales, Yasser; Cortes Maldonado, Ismael; Cortese, Pietro; Cosentino, Mauro Rogerio; Costa, Filippo; Crochet, Philippe; Cruz Albino, Rigoberto; Cuautle Flores, Eleazar; Cunqueiro Mendez, Leticia; Dahms, Torsten; Dainese, Andrea; Danu, Andrea; Das, Debasish; Das, Indranil; Das, Supriya; Dash, Ajay Kumar; Dash, Sadhana; De, Sudipan; De Caro, Annalisa; De Cataldo, Giacinto; De Cuveland, Jan; De Falco, Alessandro; De Gruttola, Daniele; De Marco, Nora; De Pasquale, Salvatore; Deisting, Alexander; Deloff, Andrzej; Denes, Ervin Sandor; D'Erasmo, Ginevra; Di Bari, Domenico; Di Mauro, Antonio; Di Nezza, Pasquale; Diaz Corchero, Miguel Angel; Dietel, Thomas; Dillenseger, Pascal; Divia, Roberto; Djuvsland, Oeystein; Dobrin, Alexandru Florin; Dobrowolski, Tadeusz Antoni; Domenicis Gimenez, Diogenes; Donigus, Benjamin; Dordic, Olja; Dubey, Anand Kumar; Dubla, Andrea; Ducroux, Laurent

    2015-01-01T23:59:59.000Z

    We have studied the transverse-momentum ($p_{\\rm T}$) dependence of the inclusive J/$\\psi$ production in p-Pb collisions at $\\sqrt{s_{\\rm NN}} = 5.02$ TeV, in three center-of-mass rapidity ($y_{\\rm cms}$) regions, down to zero $p_{\\rm T}$. Results in the forward and backward rapidity ranges ($2.03 < y_{\\rm cms} < 3.53$ and $-4.46 nuclear modification factor are presented for each of the rapidity intervals, as well as the J/$\\psi$ mean $p_{\\rm T}$ values. Forward and mid-rapidity results show a suppression of the J/$\\psi$ yield, with respect to pp collisions, which decreases with increasing $p_{\\rm T}$. At backward rapidity no significant J/$\\psi$ suppression is observed. Theoretical models including a combinatio...

  4. Scattering lengths for collisions of hydrogen and deuterium atoms

    E-Print Network [OSTI]

    Chu, X.; Jamieson, M.J.

    Chu,X. Jamieson,M.J. Dalgarno,A. Journal of Physics B: Atomic, Molecular and Optical Physics, Vol. 36 pp L415-L418

  5. Core-Corona Separation in Ultrarelativistic Heavy Ion Collisions

    SciTech Connect (OSTI)

    Werner, Klaus [SUBATECH, University of Nantes-IN2P3/CNRS-EMN, Nantes 44000 (France)

    2007-04-13T23:59:59.000Z

    Simple geometrical considerations show that the collision zone in high energy nuclear collisions may be divided into a central part ('core'), with high energy densities, and a peripheral part ('corona'), with smaller energy densities, more like in pp or pA collisions. We present calculations that allow us to separate these two contributions, and which show that the corona contribution is quite small (but not negligible) for central collisions, but gets increasingly important with decreasing centrality. We will discuss consequences concerning results obtained in heavy ion collisions at the BNL Relativistic Heavy Ion Collider and CERN Super Proton Synchrotron.

  6. Proc. 23rd Winter Workshop on Nuclear Dynamics (2007) 000000

    E-Print Network [OSTI]

    2007-01-01T23:59:59.000Z

    Proc. 23rd Winter Workshop on Nuclear Dynamics (2007) 000­000 23rd Winter Workshop on Nuclear collisions, where such nuclear effects should not be present. The RHIC experiments have also explored Au

  7. Measurements of Dihadron Correlations Relative to the Event Plane in Au+Au Collisions at $\\sqrt{s_{NN}}=200$ GeV

    E-Print Network [OSTI]

    H. Agakishiev; M. M. Aggarwal; Z. Ahammed; A. V. Alakhverdyants; I. Alekseev; J. Alford; B. D. Anderson; C. D. Anson; D. Arkhipkin; G. S. Averichev; J. Balewski; D. R. Beavis; N. K. Behera; R. Bellwied; M. J. Betancourt; R. R. Betts; A. Bhasin; A. K. Bhati; H. Bichsel; J. Bielcik; J. Bielcikova; B. Biritz; L. C. Bland; W. Borowski; J. Bouchet; E. Braidot; A. V. Brandin; A. Bridgeman; S. G. Brovko; E. Bruna; S. Bueltmann; I. Bunzarov; T. P. Burton; X. Z. Cai; H. Caines; M. Calderón de la Barca Sánchez; D. Cebra; R. Cendejas; M. C. Cervantes; Z. Chajecki; P. Chaloupka; S. Chattopadhyay; H. F. Chen; J. H. Chen; J. Y. Chen; L. Chen; J. Cheng; M. Cherney; A. Chikanian; K. E. Choi; W. Christie; P. Chung; M. J. M. Codrington; R. Corliss; J. G. Cramer; H. J. Crawford; S. Dash; A. Davila Leyva; L. C. De Silva; R. R. Debbe; T. G. Dedovich; A. A. Derevschikov; R. Derradi de Souza; L. Didenko; P. Djawotho; S. M. Dogra; X. Dong; J. L. Drachenberg; J. E. Draper; J. C. Dunlop; L. G. Efimov; M. Elnimr; J. Engelage; G. Eppley; M. Estienne; L. Eun; O. Evdokimov; R. Fatemi; J. Fedorisin; R. G. Fersch; P. Filip; E. Finch; V. Fine; Y. Fisyak; C. A. Gagliardi; D. R. Gangadharan; A. Geromitsos; F. Geurts; P. Ghosh; Y. N. Gorbunov; A. Gordon; O. Grebenyuk; D. Grosnick; S. M. Guertin; A. Gupta; W. Guryn; B. Haag; O. Hajkova; A. Hamed; L-X. Han; J. W. Harris; J. P. Hays-Wehle; M. Heinz; S. Heppelmann; A. Hirsch; E. Hjort; G. W. Hoffmann; D. J. Hofman; B. Huang; H. Z. Huang; T. J. Humanic; L. Huo; G. Igo; P. Jacobs; W. W. Jacobs; C. Jena; F. Jin; J. Joseph; E. G. Judd; S. Kabana; K. Kang; J. Kapitan; K. Kauder; H. Ke; D. Keane; A. Kechechyan; D. Kettler; D. P. Kikola; J. Kiryluk; A. Kisiel; V. Kizka; A. G. Knospe; D. D. Koetke; T. Kollegger; J. Konzer; I. Koralt; L. Koroleva; W. Korsch; L. Kotchenda; V. Kouchpil; P. Kravtsov; K. Krueger; M. Krus; L. Kumar; P. Kurnadi; M. A. C. Lamont; J. M. Landgraf; S. LaPointe; J. Lauret; A. Lebedev; R. Lednicky; J. H. Lee; W. Leight; M. J. LeVine; C. Li; L. Li; N. Li; W. Li; X. Li; X. Li; Y. Li; Z. M. Li; M. A. Lisa; F. Liu; H. Liu; J. Liu; T. Ljubicic; W. J. Llope; R. S. Longacre; W. A. Love; Y. Lu; E. V. Lukashov; X. Luo; G. L. Ma; Y. G. Ma; D. P. Mahapatra; R. Majka; O. I. Mall; L. K. Mangotra; R. Manweiler; S. Margetis; C. Markert; H. Masui; H. S. Matis; Yu. A. Matulenko; D. McDonald; T. S. McShane; A. Meschanin; R. Milner; N. G. Minaev; S. Mioduszewski; A. Mischke; M. K. Mitrovski; B. Mohanty; M. M. Mondal; B. Morozov; D. A. Morozov; M. G. Munhoz; M. Naglis; B. K. Nandi; T. K. Nayak; P. K. Netrakanti; L. V. Nogach; S. B. Nurushev; G. Odyniec; A. Ogawa; Oh; Ohlson; V. Okorokov; E. W. Oldag; D. Olson; M. Pachr; B. S. Page; S. K. Pal; Y. Pandit; Y. Panebratsev; T. Pawlak; H. Pei; T. Peitzmann; C. Perkins; W. Peryt; S. C. Phatak; P. Pile; M. Planinic; M. A. Ploskon; J. Pluta; D. Plyku; N. Poljak; A. M. Poskanzer; B. V. K. S. Potukuchi; C. B. Powell; D. Prindle; C. Pruneau; N. K. Pruthi; P. R. Pujahari; J. Putschke; H. Qiu; R. Raniwala; S. Raniwala; R. L. Ray; R. Redwine; R. Reed; H. G. Ritter; J. B. Roberts; O. V. Rogachevskiy; J. L. Romero; A. Rose; L. Ruan; J. Rusnak; N. R. Sahoo; S. Sakai; I. Sakrejda; T. Sakuma; S. Salur; J. Sandweiss; E. Sangaline; A. Sarkar; J. Schambach; R. P. Scharenberg; A. M. Schmah; T. R. Schuster; J. Seele; J. Seger; I. Selyuzhenkov; P. Seyboth; E. Shahaliev; M. Shao; M. Sharma; S. S. Shi; Q. Y. Shou; E. P. Sichtermann; F. Simon; R. N. Singaraju; M. J. Skoby; N. Smirnov; H. M. Spinka; B. Srivastava; T. D. S. Stanislaus; D. Staszak; S. G. Steadman; J. R. Stevens; R. Stock; M. Strikhanov; B. Stringfellow; A. A. P. Suaide; M. C. Suarez; N. L. Subba; 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; D. Thein; J. H. Thomas; J. Tian; A. R. Timmins; D. Tlusty; M. Tokarev; V. N. Tram; S. Trentalange; R. E. Tribble; Tribedy; O. D. Tsai; T. Ullrich; D. G. Underwood; G. Van Buren; G. van Nieuwenhuizen; J. A. Vanfossen, Jr.; R. Varma; G. M. S. Vasconcelos; A. N. Vasiliev; F. Videbćk; Y. P. Viyogi; S. Vokal; 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; C. Whitten Jr.; H. Wieman; S. W. Wissink; R. Witt; W. Witzke; Y. F. Wu; Xiao; W. Xie; H. Xu; N. Xu; Q. H. Xu; W. Xu; Y. Xu; Z. Xu; L. Xue; Y. Yang; P. Yepes; K. Yip; I-K. Yoo; M. Zawisza; H. Zbroszczyk; W. Zhan; J. B. Zhang; S. Zhang; W. M. Zhang; X. P. Zhang; Y. Zhang; Z. P. Zhang; J. Zhao; C. Zhong; W. Zhou; X. Zhu; Y. H. Zhu; R. Zoulkarneev; Y. Zoulkarneeva

    2013-05-16T23:59:59.000Z

    Dihadron azimuthal correlations containing a high transverse momentum ($\\pt$) trigger particle are sensitive to the properties of the nuclear medium created at RHIC through the strong interactions occurring between the traversing parton and the medium, i.e. jet-quenching. Previous measurements revealed a strong modification to dihadron azimuthal correlations in Au+Au collisions with respect to \\pp\\ and \\dAu\\ collisions. The modification increases with the collision centrality, suggesting a path-length dependence to the jet-quenching effect. This paper reports STAR measurements of dihadron azimuthal correlations in mid-central (20-60\\%) Au+Au collisions at $\\snn=200$~GeV as a function of the trigger particle's azimuthal angle relative to the event plane, $\\phis=|\\phit-\\psiEP|$. The azimuthal correlation is studied as a function of both the trigger and associated particle $\\pt$. The subtractions of the combinatorial background and anisotropic flow, assuming Zero Yield At Minimum (\\zyam), are described. The away-side correlation is strongly modified, and the modification varies with $\\phis$, which is expected to be related to the path-length that the away-side parton traverses. The pseudo-rapidity ($\\deta$) dependence of the near-side correlation, sensitive to long range $\\deta$ correlations (the ridge), is also investigated. The ridge and jet-like components of the near-side correlation are studied as a function of $\\phis$. The ridge appears to drop with increasing $\\phis$ while the jet-like component remains approximately constant. ...

  8. New results on nuclear dependence of J/psi and psi' production in 450 GeV pA collisions

    E-Print Network [OSTI]

    R. Shahoyan

    2002-07-03T23:59:59.000Z

    To understand the reliability of the charmonia suppression as a signature of the Quark-Gluon Plasma formation in nucleus-nucleus collisions it is important first to understand the details of the production of J/psi and psi' in pA interactions and the difference in the suppression of these two states. This report presents the results of the study by the NA50 collaboration of the J/psi and psi' production in pA interactions at 450 GeV beam energy and its dependence on rapidity. It is shown that the psi' suffers more suppression than the J/psi, which is consistent with a similar observation made at 800 GeV beam energy by the E866/NuSea collaboration.

  9. arc-continent collision origin: Topics by E-print Network

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

    Piero Olla 2008-01-23 51 Lepton-pair production in nuclear collisions - past, present, future Nuclear Experiment (arXiv) Summary: The key results on lepton-pair production...

  10. Collisions of Nuclei: New Ideas for Hard

    E-Print Network [OSTI]

    cosmic rays impacting on planetary objects. In the lab: high energy nuclear collisions! BNL RHIC Au environment Summary [With W. Liu, Phys.Rev.C77:054902,2008 Phys.Rev.C78:037902,2008] [In progress, with R Pb+Pb @ s = 5.5 TeV First run 2010 ? ???? #12;TIFR 2009 7Rainer Fries Sketch of a HE Nuclear

  11. agip nucleare: Topics by E-print Network

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

    shadowing in high-energy nuclear collisions are presented. N. Armesto 2006-07-05 3 Nuclear Power CiteSeer Summary: this report does not contain recommendations or solutions...

  12. Core-Corona Separation in Ultra-Relativistic Heavy Ion Collisions

    E-Print Network [OSTI]

    Klaus Werner

    2007-04-10T23:59:59.000Z

    Simple geometrical considerations show that the collision zone in high energy nuclear collisions may be divided into a central part (``core''), with high energy densities, and a peripheral part (``corona''), with smaller energy densities, more like in pp or pA collisions. We present calculations which allow to separate these two contributions, and which show that the corona contribution is quite small (but not negligible) for central collisions, but gets increasingly important with decreasing centrality. We will discuss consequences concerning results obtained in heavy ion collisions at the Relativistic Heavy Ion Collider (RHIC) and the Super Proton Synchrotron (SPS).

  13. Neutron transport analysis for nuclear reactor design

    DOE Patents [OSTI]

    Vujic, Jasmina L. (Lisle, IL)

    1993-01-01T23:59:59.000Z

    Replacing regular mesh-dependent ray tracing modules in a collision/transfer probability (CTP) code with a ray tracing module based upon combinatorial geometry of a modified geometrical module (GMC) provides a general geometry transfer theory code in two dimensions (2D) for analyzing nuclear reactor design and control. The primary modification of the GMC module involves generation of a fixed inner frame and a rotating outer frame, where the inner frame contains all reactor regions of interest, e.g., part of a reactor assembly, an assembly, or several assemblies, and the outer frame, with a set of parallel equidistant rays (lines) attached to it, rotates around the inner frame. The modified GMC module allows for determining for each parallel ray (line), the intersections with zone boundaries, the path length between the intersections, the total number of zones on a track, the zone and medium numbers, and the intersections with the outer surface, which parameters may be used in the CTP code to calculate collision/transfer probability and cross-section values.

  14. Neutron transport analysis for nuclear reactor design

    DOE Patents [OSTI]

    Vujic, J.L.

    1993-11-30T23:59:59.000Z

    Replacing regular mesh-dependent ray tracing modules in a collision/transfer probability (CTP) code with a ray tracing module based upon combinatorial geometry of a modified geometrical module (GMC) provides a general geometry transfer theory code in two dimensions (2D) for analyzing nuclear reactor design and control. The primary modification of the GMC module involves generation of a fixed inner frame and a rotating outer frame, where the inner frame contains all reactor regions of interest, e.g., part of a reactor assembly, an assembly, or several assemblies, and the outer frame, with a set of parallel equidistant rays (lines) attached to it, rotates around the inner frame. The modified GMC module allows for determining for each parallel ray (line), the intersections with zone boundaries, the path length between the intersections, the total number of zones on a track, the zone and medium numbers, and the intersections with the outer surface, which parameters may be used in the CTP code to calculate collision/transfer probability and cross-section values. 28 figures.

  15. Multiphase transport model for heavy ion collisions at RHIC

    E-Print Network [OSTI]

    Zi-wei Lin; Subrata Pal; C. M. Ko; Bao-An Li; Bin Zhang

    2001-05-18T23:59:59.000Z

    Using a multiphase transport model (AMPT) with both partonic and hadronic interactions, we study the multiplicity and transverse momentum distributions of charged particles such as pions, kaons and protons in central Au+Au collisions at RHIC energies. Effects due to nuclear shadowing and jet quenching on these observables are also studied. We further show preliminary results on the production of multistrange baryons from the strangeness-exchange reactions during the hadronic stage of heavy ion collisions.

  16. First Order Phase Transition in Intermediate Energy Heavy Ion Collisions

    E-Print Network [OSTI]

    J. Pan; S. Das Gupta; M. Grant

    1997-11-01T23:59:59.000Z

    We model the disassembly of an excited nuclear system formed as a result of a heavy ion collision. We find that, as the beam energy in central collisions in varied, the dissociating system crosses a liquid-gas coexistence curve, resulting in a first-order phase transition. Accessible experimental signatures are identified: a peak in specific heat, a power-law yield for composites, and a maximum in the second moment of the yield distribution.

  17. Continuously variable focal length lens

    DOE Patents [OSTI]

    Adams, Bernhard W; Chollet, Matthieu C

    2013-12-17T23:59:59.000Z

    A material preferably in crystal form having a low atomic number such as beryllium (Z=4) provides for the focusing of x-rays in a continuously variable manner. The material is provided with plural spaced curvilinear, optically matched slots and/or recesses through which an x-ray beam is directed. The focal length of the material may be decreased or increased by increasing or decreasing, respectively, the number of slots (or recesses) through which the x-ray beam is directed, while fine tuning of the focal length is accomplished by rotation of the material so as to change the path length of the x-ray beam through the aligned cylindrical slows. X-ray analysis of a fixed point in a solid material may be performed by scanning the energy of the x-ray beam while rotating the material to maintain the beam's focal point at a fixed point in the specimen undergoing analysis.

  18. Continuous lengths of oxide superconductors

    DOE Patents [OSTI]

    Kroeger, Donald M. (Knoxville, TN); List, III, Frederick A. (Andersonville, TN)

    2000-01-01T23:59:59.000Z

    A layered oxide superconductor prepared by depositing a superconductor precursor powder on a continuous length of a first substrate ribbon. A continuous length of a second substrate ribbon is overlaid on the first substrate ribbon. Sufficient pressure is applied to form a bound layered superconductor precursor powder between the first substrate ribbon and the second substrate ribbon. The layered superconductor precursor is then heat treated to establish the oxide superconducting phase. The layered oxide superconductor has a smooth interface between the substrate and the oxide superconductor.

  19. Inclusive Jet Spectra in p-Pb Collisions at ALICE

    E-Print Network [OSTI]

    Megan Connors; for the ALICE Collaboration

    2014-09-11T23:59:59.000Z

    Jet suppression has been observed in central heavy ion collisions. This suppression is attributed to partonic energy loss in the Quark Gluon Plasma (QGP) formed in such collisions. However, this measurement is influenced by all stages of the collision. It is expected that in p-Pb collisions similar initial conditions occur as in Pb-Pb collisions without creating a QGP, allowing modification to the jet spectra due to cold nuclear matter effects to be quantified. Inclusive jet spectra in p-Pb collisions at $\\sqrt{s_{\\rm NN}} = 5.02$ TeV measured by ALICE are presented. Jets are reconstructed via the anti-k$_{\\rm T}$ algorithm with different resolution parameters by combining charged tracks measured in the ALICE tracking system with the neutral energy deposited in the electromagnetic calorimeter. The jet spectra can be used to determine a nuclear modification factor $R_{\\rm pPb}$ while the jet profile in p-Pb is studied by dividing spectra measured with different resolution parameters and comparing to the same ratio measured in pp collisions.

  20. ? Production in Heavy Ion Collisions at LHC

    E-Print Network [OSTI]

    Kai Zhou; Nu Xu; Pengfei Zhuang

    2014-08-19T23:59:59.000Z

    We investigate the {\\Upsilon} production in heavy ion collisions at LHC energy in the frame of a dynamical transport approach. Both the initial production and in-medium regeneration and both the cold and hot nuclear matter effects are included in the calculations. In comparison with the ground state {\\Upsilon}(1s), the excited state {\\Upsilon}(2s) is much more sensitive to the heavy quark potential at finite temperature.

  1. Energy loss of charm quarks from $J/?$ production in cold nuclear matter

    E-Print Network [OSTI]

    Li-Hua Song; Wen-Dan Miao; Chun-Gui Duan

    2013-12-15T23:59:59.000Z

    $J/\\psi$ suppression in p-A collisions is studied by considering the nuclear effects on parton distribution, energy loss of beam proton and the finial state energy loss of color octet $c\\overline{c}$. The leading-order computations for $J/\\psi$ production cross-section ratios $R_{W/Be}(x_{F})$ are presented and compared with the selected E866 experimental data with the $c\\overline{c}$ remaining colored on its entire path in the medium. It is shown that the combination of the different nuclear effects accounts quite well for the observed $J/\\psi$ suppression in the experimental data. It is found that the $J/\\psi$ suppression on $R_{W/Be}(x_{F})$ from the initial state nuclear effects is more important than that induced by the energy loss of color octet $c\\overline{c}$ in the large $x_F$ region. Whether the $c\\overline{c}$ pair energy loss is linear or quadratic with the path length is not determined. The obtained $c\\overline{c}$ pair energy loss per unit path length $\\alpha=2.78\\pm0.81$ GeV/fm, which indicates that the heavy quark in cold nuclear matter can lose more energy compared to the outgoing light quark.

  2. Measurement of Inclusive Jet Charged-Particle Fragmentation Functions in Pb+Pb Collisions at ?s[subscript NN] = 2.76 TeV with the ATLAS Detector

    E-Print Network [OSTI]

    Taylor, Frank E.

    Measurements of charged-particle fragmentation functions of jets produced in ultra-relativistic nuclear collisions can provide insight into the modification of parton showers in the hot, dense medium created in the collisions. ...

  3. Early hydrodynamic evolution of a stellar collision

    SciTech Connect (OSTI)

    Kushnir, Doron; Katz, Boaz [Institute for Advanced Study, Einstein Drive, Princeton, NJ 08540 (United States)

    2014-04-20T23:59:59.000Z

    The early phase of the hydrodynamic evolution following the collision of two stars is analyzed. Two strong shocks propagate from the contact surface and move toward the center of each star at a velocity that is a small fraction of the velocity of the approaching stars. The shocked region near the contact surface has a planar symmetry and a uniform pressure. The density vanishes at the (Lagrangian) surface of contact, and the speed of sound diverges there. The temperature, however, reaches a finite value, since as the density vanishes, the finite pressure is radiation dominated. For carbon-oxygen white dwarf (CO WD) collisions, this temperature is too low for any appreciable nuclear burning shortly after the collision, which allows for a significant fraction of the mass to be highly compressed to the density required for efficient {sup 56}Ni production in the detonation wave that follows. This property is crucial for the viability of collisions of typical CO WD as progenitors of type Ia supernovae, since otherwise only massive (>0.9 M {sub ?}) CO WDs would have led to such explosions (as required by all other progenitor models). The divergence of the speed of sound limits numerical studies of stellar collisions, as it makes convergence tests exceedingly expensive unless dedicated schemes are used. We provide a new one-dimensional Lagrangian numerical scheme to achieve this. A self-similar planar solution is derived for zero-impact parameter collisions between two identical stars, under some simplifying assumptions (including a power-law density profile), which is the planar version of previous piston problems that were studied in cylindrical and spherical symmetries.

  4. Radiological consequences of ship collisions that might occur in U.S. Ports during the shipment of foreign research reactor spent nuclear fuel to the United States in break-bulk freighters

    SciTech Connect (OSTI)

    Sprung, J.L.; Bespalko, S.J.; Massey, C.D.; Yoshimura, R. [Sandia National Laboratory, Albuquerque, NM (United States); Johnson, J.D. [GRAM Inc., Albuquerque, NM (United States); Reardon, P.C. [PCRT Technologies, Albuquerque, NM (United States); Ebert, M.W.; Gallagher D.W. [Science Applications International Corp., Reston, VA (United States)

    1996-08-01T23:59:59.000Z

    Accident source terms, source term probabilities, consequences, and risks are developed for ship collisions that might occur in U.S. ports during the shipment of spent fuel from foreign research reactors to the United States in break-bulk freighters.

  5. Precision Measurement of the n-3He Incoherent Scattering Length Using Neutron Interferometry

    E-Print Network [OSTI]

    M. G. Huber; M. Arif; T. C. Black; W. C. Chen; T. R. Gentile; D. S. Hussey; D. Pushin; F. E. Wietfeldt; L. Yang

    2009-05-12T23:59:59.000Z

    We report the first measurement of the low-energy neutron-$^3$He incoherent scattering length using neutron interferometry: $b_i' = (-2.512\\pm 0.012{statistical}\\pm0.014{systematic})$ fm. This is in good agreement with a recent calculation using the AV18+3N potential. The neutron-$^3$He scattering lengths are important for testing and developing nuclear potential models that include three nucleon forces, effective field theories for few-body nuclear systems, and neutron scattering measurements of quantum excitations in liquid helium. This work demonstrates the first use of a polarized nuclear target in a neutron interferometer.

  6. Jet Reconstruction in Heavy Ion Collisions

    E-Print Network [OSTI]

    Sevil Salur

    2009-05-12T23:59:59.000Z

    Measurements of strong suppression of inclusive hadron distributions and di-hadron correlations at high $p_{T}$, while providing evidence for partonic energy loss, also suffer from geometric biases due to the competition of energy loss and fragmentation. The measurements of fully reconstructed jets is expected to lack these biases as the energy flow is measured independently of the fragmentation details. In this article, we review the recent results from the heavy ion collisions collected by the STAR experiment at RHIC on direct jet reconstruction utilizing the modern sequential recombination and cone jet reconstruction algorithms together with their background subtraction techniques. In order to assess the jet reconstruction biases a comparison with the jet cross section measurement in $\\sqrt{s}=200$ GeV p+p collisions scaled by the number of binary nucleon-nucleon collisions to account for nuclear geometric effects is performed. Comparison of the inclusive jet cross section obtained in central Au+Au events with that in $p+p$ collisions, published previously by STAR, suggests that unbiased jet reconstruction in the complex heavy ion environment indeed may be possible.

  7. Azimuthal anisotropy in U+U collisions at STAR

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

    Wang, Hui; Sorensen, Paul

    2014-12-01T23:59:59.000Z

    The azimuthal anisotropy of particle production is commonly used in high-energy nuclear collisions to study the early evolution of the expanding system. The prolate shape of uranium nuclei makes it possible to study how the geometry of the colliding nuclei affects #12;final state anisotropies. It also provides a unique opportunity to understand how entropy is produced in heavy ion collisions. In this paper, the two- and four- particle cumulant v2 (v2{2} and v2{4}) from U+U collisions at ?sNN = 193 GeV and Au+Au collisions at ?sNN = 200 GeV for inclusive charged hadrons will be presented. The STAR Zero Degreemore »Calorimeters are used to select very central collisions. Differences were observed between the multiplicity dependence of v2{2} for most central Au+Au and U+U collisions. The multiplicity dependence of v2{2} in central collisions were compared to Monte Carlo Glauber model predictions and it was seen that this model cannot explain the present results. (auth)« less

  8. Azimuthal anisotropy in U+U collisions at STAR

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

    Wang, Hui; Sorensen, Paul

    2014-12-01T23:59:59.000Z

    The azimuthal anisotropy of particle production is commonly used in high-energy nuclear collisions to study the early evolution of the expanding system. The prolate shape of uranium nuclei makes it possible to study how the geometry of the colliding nuclei affects #12;final state anisotropies. It also provides a unique opportunity to understand how entropy is produced in heavy ion collisions. In this paper, the two- and four- particle cumulant v2 (v2{2} and v2{4}) from U+U collisions at ?sNN = 193 GeV and Au+Au collisions at ?sNN = 200 GeV for inclusive charged hadrons will be presented. The STAR Zero Degree Calorimeters are used to select very central collisions. Differences were observed between the multiplicity dependence of v2{2} for most central Au+Au and U+U collisions. The multiplicity dependence of v2{2} in central collisions were compared to Monte Carlo Glauber model predictions and it was seen that this model cannot explain the present results. (auth)

  9. Nuclear Physics of Neutron Stars

    E-Print Network [OSTI]

    J. Piekarewicz

    2009-01-28T23:59:59.000Z

    Understanding the equation of state (EOS) of cold nuclear matter, namely, the relation between the pressure and energy density, is a central goal of nuclear physics that cuts across a variety of disciplines. Indeed, the limits of nuclear existence, the collision of heavy ions, the structure of neutron stars, and the dynamics of core-collapse supernova, all depend critically on the equation of state of hadronic matter. In this contribution I will concentrate on the special role that nuclear physics plays in constraining the EOS of cold baryonic matter and its impact on the properties of neutron stars.

  10. Glauber model for heavy ion collisions from low energies to high energies

    E-Print Network [OSTI]

    P. Shukla

    2001-12-13T23:59:59.000Z

    The Glauber model is extensively applied to heavy ion collision for describing a number of interaction processes over a wide range of energies from near the Coulomb barrier to higher energies. The model gives the nucleus-nucleus interaction in terms of interaction between the constituent nucleons with a given density distribution. The model is a semiclassical model picturing the nuclear collision in the impact parameter representation where the nuclei move along the collision direction in a straight path. In these lectures we derive this model and discuss its applications in variety of problems in nuclear and high energy physics.

  11. Antiflow of kaons in relativistic heavy ion collisions

    E-Print Network [OSTI]

    Pal, S.; Ko, Che Ming; Lin, ZW; Zhang, B.

    2000-01-01T23:59:59.000Z

    We compare relativistic transport model calculations to recent data on the sideward flow of neutral strange K-s(0) mesons for Au+Au collisions at 6A GeV. A soft nuclear equation of state is found to describe very well the positive proton flow data...

  12. A short course on Relativistic Heavy Ion Collisions

    E-Print Network [OSTI]

    A. K. Chaudhuri

    2012-07-23T23:59:59.000Z

    Some ideas/concepts in relativistic heavy ion collisions are discussed. To a large extent, the discussions are non-comprehensive and non-rigorous. It is intended for fresh graduate students of Homi Bhabha National Institute, Kolkata Centre, who are intending to pursue career in theoretical /experimental high energy nuclear physics. Comments and criticisms will be appreciated.

  13. A short course on Relativistic Heavy Ion Collisions

    E-Print Network [OSTI]

    Chaudhuri, A K

    2012-01-01T23:59:59.000Z

    Some ideas/concepts in relativistic heavy ion collisions are discussed. To a large extent, the discussions are non-comprehensive and non-rigorous. It is intended for fresh graduate students of Homi Bhabha National Institute, Kolkata Centre, who are intending to pursue career in theoretical /experimental high energy nuclear physics. Comments and criticisms will be appreciated.

  14. Initiative in Nuclear Theory at the Variable Energy Cyclotron Centre

    E-Print Network [OSTI]

    D. K. Srivastava; J. Alam; D. N. Basu; A. K. Chaudhuri; J. N. De; K. Krishan; S. Pal

    2005-06-24T23:59:59.000Z

    We recall the path breaking contributions of the nuclear theory group of the Variable Energy Cyclotron Centre, Kolkata. From a beginning of just one person in 1970s, the group has steadily developed into a leading group in the country today, with seminal contributions to almost the entire range of nuclear physics, viz., low energy nuclear reactions, nuclear structure, deep inelastic collisions, fission, liquid to gas phase transitions, nuclear matter, equation of state, mass formulae, neutron stars, relativistic heavy ion collisions, medium modification of hadron properties, quark gluon plasma, and cosmology of early universe.

  15. Jet absorption and corona effect at RHIC. Extracting collision geometry from experimental data

    E-Print Network [OSTI]

    V. S. Pantuev

    2007-05-14T23:59:59.000Z

    We demonstrate a possible existence of a finite formation time of strongly interacting plasma in nuclear collisions at RHIC from recent experimental data. To show this, we use a simple model based on Monte Carlo simulation of nucleus-nucleus collisions with realistic nuclear density distribution. The most striking feature of the experimental data - an absence of absorption of high transverse momentum pions in the reaction plane direction for mid-peripheral collisions - points to the presence of a surface zone with no absorption and strong suppression in the inner core. A natural interpretation of such a zone could be the plasma formation time T~2-3 fm/c. The existence of a formation time could dramatically change our understanding of many experimentally observed features. With this assumption we describe the angular anisotropy of high transverse momentum pions with respect to the reaction plane and the centrality dependence of nuclear modification factor in Au+Au and Cu+Cu collisions.

  16. Effects of momentum-dependent nuclear potential on two-nucleon correlation functions and light cluster production in intermediate energy heavy-ion collisions RID A-2398-2009

    E-Print Network [OSTI]

    Chen, LW; Ko, Che Ming; Li, Ba.

    2004-01-01T23:59:59.000Z

    Using an isospin- and momentum-dependent transport model, we study the effects due to the momentum dependence of isoscalar nuclear potential as well as that of symmetry potential on two-nucleon correlation functions and light cluster production...

  17. Resonant electron-CF collision processes

    SciTech Connect (OSTI)

    Trevisan, Cynthia S.; Orel, Ann E.; Rescigno, Thomas N.

    2005-03-18T23:59:59.000Z

    Electronic structure methods are combined with variationalfixed-nuclei electron scattering calculations and nuclear dynamicsstudies to characterize resonant vibrational excitation and electronattachment processes in collisions between low-energy electrons and CFradicals. Several low-lying negative ion states are found which give riseto strong vibrational excitation and which are expected to dominate thelow-energy electron scattering cross sections. We have also studiedseveral processes which could lead to production of negative ions (F- andC-), However, in contrast to other recent predictions, we do not find CFin itsground state to be a significant source of negative ion productionwhen interacting with thermal electrons.

  18. Microscope collision protection apparatus

    DOE Patents [OSTI]

    DeNure, Charles R. (Pocatello, ID)

    2001-10-23T23:59:59.000Z

    A microscope collision protection apparatus for a remote control microscope which protects the optical and associated components from damage in the event of an uncontrolled collision with a specimen, regardless of the specimen size or shape. In a preferred embodiment, the apparatus includes a counterbalanced slide for mounting the microscope's optical components. This slide replaces the rigid mounts on conventional upright microscopes with a precision ball bearing slide. As the specimen contacts an optical component, the contacting force will move the slide and the optical components mounted thereon. This movement will protect the optical and associated components from damage as the movement causes a limit switch to be actuated, thereby stopping all motors responsible for the collision.

  19. Thermally Fluctuating Second-Order Viscous Hydrodynamics and Heavy-Ion Collisions

    E-Print Network [OSTI]

    C. Young; J. I. Kapusta; C. Gale; S. Jeon; B. Schenke

    2014-07-03T23:59:59.000Z

    The fluctuation-dissipation theorem requires the presence of thermal noise in viscous fluids. The time and length scales of heavy ion collisions are small enough so that the thermal noise can have a measurable effect on observables. Thermal noise is included in numerical simulations of high energy lead-lead collisions, increasing average values of the momentum eccentricity and contributing to its event by event fluctuations.

  20. Viscosity of High Energy Nuclear Fluids

    E-Print Network [OSTI]

    V. Parihar; A. Widom; D. Drosdoff; Y. N. Srivastava

    2007-03-15T23:59:59.000Z

    Relativistic high energy heavy ion collision cross sections have been interpreted in terms of almost ideal liquid droplets of nuclear matter. The experimental low viscosity of these nuclear fluids have been of considerable recent quantum chromodynamic interest. The viscosity is here discussed in terms of the string fragmentation models wherein the temperature dependence of the nuclear fluid viscosity obeys the Vogel-Fulcher-Tammann law.

  1. Multiplicities in Pb-Pb central collisions at the LHC from running coupling evolution and RHIC data

    E-Print Network [OSTI]

    Javier L. Albacete

    2007-07-18T23:59:59.000Z

    Predictions for the pseudorapidity density of charged particles produced in Pb-Pb central collisions at $\\sqrt{s_{NN}}=5.5$ TeV are presented. Particle production in such collisions is computed in the framework of k_t-factorization, using running coupling non-linear evolution to determine the transverse momentum and rapidity dependence of the nuclear unintegrated gluon distributions.

  2. Photon-photon collisions

    SciTech Connect (OSTI)

    Brodsky, S.J.

    1988-07-01T23:59:59.000Z

    Highlights of the VIIIth International Workshop on Photon-Photon Collisions are reviewed. New experimental and theoretical results were reported in virtually every area of ..gamma gamma.. physics, particularly in exotic resonance production and tests of quantum chromodynamics where asymptotic freedom and factorization theorems provide predictions for both inclusive and exclusive ..gamma gamma.. reactions at high momentum transfer. 73 refs., 12 figs.

  3. Nuclear Engineering Nuclear Criticality Safety

    E-Print Network [OSTI]

    Kemner, Ken

    development, Nuclear Operations Division (NOD) waste management and storage activities and other laboratoryNuclear Engineering Nuclear Criticality Safety The Nuclear Engineering Division (NE) of Argonne National Laboratory is experienced in performing criticality safety and shielding evaluations for nuclear

  4. Nuclear reactor

    DOE Patents [OSTI]

    Thomson, Wallace B. (Severna Park, MD)

    2004-03-16T23:59:59.000Z

    A nuclear reactor comprising a cylindrical pressure vessel, an elongated annular core centrally disposed within and spaced from the pressure vessel, and a plurality of ducts disposed longitudinally of the pressure vessel about the periphery thereof, said core comprising an annular active portion, an annular reflector just inside the active portion, and an annular reflector just outside the active a portion, said annular active portion comprising rectangular slab, porous fuel elements radially disposed around the inner reflector and extending the length of the active portion, wedge-shaped, porous moderator elements disposed adjacent one face of each fuel element and extending the length of the fuel element, the fuel and moderator elements being oriented so that the fuel elements face each other and the moderator elements do likewise, adjacent moderator elements being spaced to provide air inlet channels, and adjacent fuel elements being spaced to provide air outlet channels which communicate with the interior of the peripheral ducts, and means for introducing air into the air inlet channels which passes through the porous moderator elements and porous fuel elements to the outlet channel.

  5. Pion and photon production in heavy ion collisions

    E-Print Network [OSTI]

    G. David

    2009-03-02T23:59:59.000Z

    Measurement of neutral pions and direct photons are closely connected experimentally, on the other hand they probe quite different aspects of relativistic heavy ion collisions. In this short review of the $\\pi^0$ results from the PHENIX experiment at RHIC our focus is on the $\\phi$-integrated nuclear modification factor, its energy and system size dependence, and the impact of these results on parton energy loss models. We also discuss the current status of high $p_T$ and thermal direct photon measurements both in $p$ + $p$ and Au+Au collisions. Recognizing the advantages of measuring not only the "signal", but also all the "references" needed for proper interpretation in the same experiments (with same or similar systematics) we argue that RHIC should regularly include $d$ + A and even $d$ + $d$ collisions into its system size and energy scan.

  6. Environmental Stresses Disrupt Telomere Length Homeostasis

    E-Print Network [OSTI]

    Shamir, Ron

    Environmental Stresses Disrupt Telomere Length Homeostasis Gal Hagit Romano1,2,3. , Yaniv Harari1 and Biotechnology, Tel Aviv University, Tel Aviv, Israel, 2 Blavatnik School of Computer Science, Tel Aviv response to environmental signals. These results demonstrate that telomere length can be manipulated

  7. Variable Length Path Coupling Thomas P. Hayes

    E-Print Network [OSTI]

    Hayes, Thomas

    length path coupling theorem, we im- prove the upper bound on the mixing time of the Glauber dynamics . By a "coupling" for this chain, we will mean a joint stochastic process (Xt, Yt) on × such that eachVariable Length Path Coupling Thomas P. Hayes Eric Vigoda July 17, 2006 Abstract We present a new

  8. Measurement of inclusive jet spectra in pp, p-Pb, and Pb-Pb collisions with the ALICE detector

    E-Print Network [OSTI]

    Rüdiger Haake; for the ALICE Collaboration

    2014-10-16T23:59:59.000Z

    Highly energetic jets are sensitive probes for the kinematic properties and the topology of high energy hadron collisions. Jets are collimated sprays of charged and neutral particles, which are produced in fragmentation of hard scattered partons from an early stage of the collision. In ALICE, jets have been measured in pp, p-Pb, and Pb-Pb collisions at several collision energies. While analyses of Pb-Pb events unveil properties of the hot and dense medium formed in heavy-ion collisions, pp and p-Pb collisions can shed light on hadronization and cold nuclear matter effects in jet production. Additionally, pp and p-Pb serve as a baseline for disentangling hot and cold nuclear matter effects. A possible modification of the initial state is tested in p-Pb analyses. For the extraction of a jet signal, the exact evaluation of the background from the underlying event is an especially important ingredient. Due to the different nature of underlying events, each collision system requires a different analysis technique for removing the effect of the background on the jet sample. The focus of this publication is on the ALICE measurements of nuclear modification factors connecting p-Pb and Pb-Pb events to pp collisions. Furthermore, the radial jet structure is explored by comparing jet spectra reconstructed with different resolution parameters.

  9. Proc. 19th Winter Workshop on Nuclear Dynamics (2003) 000000

    E-Print Network [OSTI]

    Bauer, Wolfgang

    2003-01-01T23:59:59.000Z

    Proc. 19th Winter Workshop on Nuclear Dynamics (2003) 000­000 19th Winter Workshop on Nuclear and Nuclear Collisions via the Test Particle Method - Similarities and Differences Wolfgang Bauer1,a 1 momentum. PACS: 24.10.-i, 24.10.Lx, 25.70.-z, 25.75.-q, 26.50.+x, 97.60.Bw 1. Nuclear Dynamics Wong [1

  10. Equilibrium in heavy ion collisions

    E-Print Network [OSTI]

    Koch, Volker; Majumder, Abhijit

    2008-01-01T23:59:59.000Z

    Proc. 19th Winter Workshop on Nuclear Dynamics (2003)000 19th Winter Workshop on Nuclear Dynamics Breckenridge,

  11. Jet measurements in p+p and d+Au collisions with STAR at RHIC

    E-Print Network [OSTI]

    Jan Kapitan; for the STAR Collaboration

    2010-12-02T23:59:59.000Z

    Full jet reconstruction in heavy-ion collisions is a promising tool for the quantitative study of properties of the dense medium produced at RHIC. In addition to baseline measurements in p+p, results from d+Au collisions are needed to disentangle initial state nuclear effects from medium-induced k_T broadening and jet quenching. We present mid-rapidity inclusive jet p_T spectra and di-jet correlations (k_T) in 200~GeV p+p and d+Au collisions from the 2007-2008 RHIC run.

  12. Heavy-flavour production and multiplicity dependence in pp and p--Pb collisions with ALICE

    E-Print Network [OSTI]

    Elena Bruna; for the ALICE Collaboration

    2014-09-17T23:59:59.000Z

    The production of heavy quarks in pp collisions provides a precision test of perturbative QCD calculations at the LHC energies. More complex collision systems like p--Pb collisions allow studies of cold nuclear matter effects, such as modifications of the parton distribution functions at small x and of the $\\kt$ broadening effect. We present the ALICE results of prompt D-meson production as a function of the charged-particle multiplicity, in pp and p--Pb collisions at $\\sqrt{s}=7$ TeV and $\\sqrt{s_{NN}}=5.02$ TeV respectively. The per-event yield of D mesons in different multiplicity and $\\pt$ intervals are compared for pp and p--Pb collisions to study the contribution of multi-parton interactions to open-charm production. Angular correlations of prompt D mesons and heavy-flavour decay electrons with charged hadrons in pp and p-Pb collisions are also shown in different kinematic ranges and compared to pQCD models. These measurements provide information on the charm fragmentation processes, on cold nuclear matter effects on charm production, and on the participation of charm in the collective motion arising in small collision systems like p-Pb.

  13. Planning under uncertainty for dynamic collision avoidance

    E-Print Network [OSTI]

    Temizer, Selim, 1977-

    2011-01-01T23:59:59.000Z

    We approach dynamic collision avoidance problem from the perspective of designing collision avoidance systems for unmanned aerial vehicles. Before unmanned aircraft can fly safely in civil airspace, robust airborne collision ...

  14. Isotope analysis in central heavy ion collisions at intermediate energies

    E-Print Network [OSTI]

    NUCL-EX Collaboration; :; E. Geraci; U. Abbondanno; L. Bardelli; S. Barlini; M. Bini; M. Bruno; F. Cannata; G. Casini; M. Chiari; M. D'Agostino; J. DeSanctis; A. Giussani; F. Gramegna; V. L. Kravchuk; A. L. Lanchais; P. Marini; A. Moroni; A. Nannini; A. Olmi; A. Ordine; G. Pasquali; S. Piantelli; G. Poggi; G. Vannini

    2006-09-29T23:59:59.000Z

    Symmetry energy is a key quantity in the study of the equation of state of asymmetric nuclear matter. Heavy ion collisions at low and intermediate energies, performed at Laboratori Nazionali di Legnaro and Laboratori Nazionali del Sud, can be used to extract information on the symmetry energy coefficient Csym, which is currently poorly known but relevant both for astrophysics and for structure of exotic nuclei.

  15. Effect of Minimal lengths on Electron Magnetism

    E-Print Network [OSTI]

    Khireddine Nouicer

    2007-07-13T23:59:59.000Z

    We study the magnetic properties of electron in a constant magnetic field and confined by a isotropic two dimensional harmonic oscillator on a space where the coordinates and momenta operators obey generalized commutation relations leading to the appearance of a minimal length. Using the momentum space representation we determine exactly the energy eigenvalues and eigenfunctions. We prove that the usual degeneracy of Landau levels is removed by the presence of the minimal length in the limits of weak and strong magnetic field.The thermodynamical properties of the system, at high temperature, are also investigated showing a new magnetic behavior in terms of the minimal length.

  16. Recent results on electroweak probes in lead-lead and proton-lead collisions from the ATLAS Detector at the LHC

    E-Print Network [OSTI]

    Brooks, William; The ATLAS collaboration

    2015-01-01T23:59:59.000Z

    Photons and weak bosons do not interact strongly with the dense and hot medium formed in nuclear collisions, and thus they should be sensitive to the nuclear modification of parton distribution functions (nPDFs). In particular, proton-lead collisions provide an excellent opportunity to test nPDFs in a less dense environment than lead-lead. The ATLAS detector, optimized for searching new physics in proton-proton collisions, is especially well equipped to measure photons, Z and W bosons in the high occupancy environment produced in heavy ion collisions. Using the full data samples of 2.76 TeV lead-lead and 5.02 TeV proton-lead collisions we will present recent results on the prompt photon, Z and W boson yields as a function of centrality, transverse momentum and rapidity, from the ATLAS experiment. The binary collision scaling of the yields will be discussed in detail.

  17. Effects of collisions and finite length on plasma waves in a single-species plasma column

    E-Print Network [OSTI]

    Anderson, Michael Wesley

    2011-01-01T23:59:59.000Z

    1.6) is ignored, the kinetic expression (1.5) is recoveredin Eq. (4.9), the kinetic expression (3.49) is recovered byof this expression in the linearized Dougherty kinetic

  18. S-wave scattering lengths and effective ranges for collisions of ground state Be atoms

    E-Print Network [OSTI]

    Jamieson, M.J.

    Jamieson,M.J. Cheung,A.S.C. Ouerdane,H. Jeung,G.H. Geum,N. Journal of Physics B, Volume 40 pp 3497-3504

  19. Nuclear Structure

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

    - A250 region - K-isomers, highest neutron orbitals, reduced pairing, higher order multipole shapes Chowdhury ATLAS User Workshop May 15, 2014 * Deep-inelastic collisions with...

  20. "Evidence for double-electron capture in the H9 -He collision"

    E-Print Network [OSTI]

    Boyer, Edmond

    V/amu have been prepared in a high-energy cluster facility consisting of a cryogenic cluster jet expansion selected high-energy projectile pulse (pulse length of 100 ms, repetition frequency of 1 Hz) consisting collision has been evidenced using the accelerator mass spectrometry method associated to a multi

  1. Sixteenth International Conference on the physics of electronic and atomic collisions

    SciTech Connect (OSTI)

    Dalgarno, A.; Freund, R.S.; Lubell, M.S.; Lucatorto, T.B. (eds.)

    1989-01-01T23:59:59.000Z

    This report contains abstracts of papers on the following topics: photons, electron-atom collisions; electron-molecule collisions; electron-ion collisions; collisions involving exotic species; ion- atom collisions, ion-molecule or atom-molecule collisions; atom-atom collisions; ion-ion collisions; collisions involving rydberg atoms; field assisted collisions; collisions involving clusters and collisions involving condensed matter.

  2. Inheritance of Cotton Fiber Length and Strength

    E-Print Network [OSTI]

    Joy, Kolbyn Seth

    2014-04-23T23:59:59.000Z

    hybrids. General combining ability (GCA) and specific combining ability (SCA) were estimated according to Griffing’s diallel Model I, Method 4 for lint percent, high volume instrument (HVI) upper half mean length (UHML), fiber bundle strength (Str...

  3. Carbon Nanotubes: Measuring Dispersion and Length

    SciTech Connect (OSTI)

    Fagan, Jeffrey A.; Bauer, Barry J.; Hobbie, Erik K.; Becker, Matthew L.; Hight-Walker, Angela; Simpson, Jeffrey R.; Chun, Jaehun; Obrzut, Jan; Bajpai, Vardhan; Phelan, Fred R.; Simien, Daneesh; Yeon Huh, Ji; Migler, Kalman B.

    2011-03-01T23:59:59.000Z

    Advanced technological uses of single-wall carbon nanotubes (SWCNTs) rely on the production of single length and chirality populations that are currently only available through liquid phase post processing. The foundation of all of these processing steps is the attainment of individualized nanotube dispersion in solution; an understanding of the collodial properties of the dispersed SWCNTs can then be used to designed appropriate conditions for separations. In many instances nanotube size, particularly length, is especially active in determining the achievable properties from a given population, and thus there is a critical need for measurement technologies for both length distribution and effective separation techniques. In this Progress Report, we document the current state of the art for measuring dispersion and length populations, including separations, and use examples to demonstrate the desirability of addressing these parameters.

  4. A length operator for canonical quantum gravity

    E-Print Network [OSTI]

    T. Thiemann

    1996-06-29T23:59:59.000Z

    We construct an operator that measures the length of a curve in four-dimensional Lorentzian vacuum quantum gravity. We work in a representation in which a $SU(2)$ connection is diagonal and it is therefore surprising that the operator obtained after regularization is densely defined, does not suffer from factor ordering singularities and does not require any renormalization. We show that the length operator admits self-adjoint extensions and compute part of its spectrum which like its companions, the volume and area operators already constructed in the literature, is purely discrete and roughly is quantized in units of the Planck length. The length operator contains full and direct information about all the components of the metric tensor which faciliates the construction of a new type of weave states which approximate a given classical 3-geometry.

  5. The rapidity and centrality dependence of nuclear modification factors at RHIC - what does bulk particle production tell us about the nuclear medium?

    E-Print Network [OSTI]

    B. H. Samset; for the BRAHMS Collaboration

    2004-03-31T23:59:59.000Z

    The BRAHMS experiment at RHIC has measured the production of charged hadrons as a function of pseudorapidity and transverse momentum in Au+Au, d+Au and p+p collisions at a common energy of sqrt(s_NN)=200GeV, and from these spectra we construct the nuclear modification factors for both ``hot'' and ``cold'' nuclear matter. In this contribution I will show how these factors evolve with pseudorapidity and collision centrality. We see a Cronin-like enhancement in d+Au collisions at midrapidity, going to a strong suppression at eta >= 2. In central Au+Au collisions we find a suppression both at mid- and forward rapidities that vanishes for peripheral collisions. We interpret this as signs of several different medium related effects modifying bulk particle production in Au+Au and d+Au collisions at RHIC energies.

  6. Nuclear Resonance Fluorescence for Nuclear Materials Assay

    E-Print Network [OSTI]

    Quiter, Brian Joseph

    2010-01-01T23:59:59.000Z

    Potential of Nuclear Resonance Fluorescence . . . . . . . .2.9.1 Nuclear ThomsonSections . . . . . . . . . . . . . . . Nuclear Resonance

  7. A comparison of methods for evaluating structure during ship collisions

    SciTech Connect (OSTI)

    Ammerman, D.J.; Daidola, J.C.

    1996-10-01T23:59:59.000Z

    A comparison is provided of the results of various methods for evaluating structure during a ship-to-ship collision. The baseline vessel utilized in the analyses is a 67.4 meter in length displacement hull struck by an identical vessel traveling at speeds ranging from 10 to 30 knots. The structural response of the struck vessel and motion of both the struck and striking vessels are assessed by finite element analysis. These same results are then compared to predictions utilizing the {open_quotes}Tanker Structural Analysis for Minor Collisions{close_quotes} (TSAMC) Method, the Minorsky Method, the Haywood Collision Process, and comparison to full-scale tests. Consideration is given to the nature of structural deformation, absorbed energy, penetration, rigid body motion, and virtual mass affecting the hydrodynamic response. Insights are provided with regard to the calibration of the finite element model which was achievable through utilizing the more empirical analyses and the extent to which the finite element analysis is able to simulate the entire collision event. 7 refs., 8 figs., 4 tabs.

  8. Actinide collisions for QED and superheavy elements with the time-dependent Hartree-Fock theory and the Balian-Veneroni variational

    E-Print Network [OSTI]

    Boyer, Edmond

    Department of Nuclear Physics, Research School of Physics and Engineering, Australian National University-nucleon transfer in actinide collisions could also be used as an alternative way to fusion in order to produce in such a collision are computed. The produced nuclei are more neutron-rich than those formed in fusion reactions

  9. Squeezing and entangling nuclear spins in helium 3

    E-Print Network [OSTI]

    Gael Reinaudi; Alice Sinatra; Aurelien Dantan; Michel Pinard

    2006-01-09T23:59:59.000Z

    We present a realistic model for transferring the squeezing or the entanglement of optical field modes to the collective ground state nuclear spin of $^3$He using metastability exchange collisions. We discuss in detail the requirements for obtaining good quantum state transfer efficiency and study the possibility to readout the nuclear spin state optically.

  10. Analysis and Optimization of "Full-Length" Diodes

    SciTech Connect (OSTI)

    Schock, Alfred

    2012-01-19T23:59:59.000Z

    A method of analyzing the axial variation of the heat generation rate, temperature, voltage, current density and emitter heat flux in a thermionic converter is described. The method is particularly useful for the case of "long" diodes, each extending over the full length of the reactor core. For a given diode geometry and fuel distribution, the analysis combines a nuclear solution of the axial fission density profile with the iterative solution of four differential equations representing the thermal, electrical, and thermionic interactions within the diode. The digital computer program developed to solve these equations can also perform a design optimization with respect to lead resistance, load voltage, and emitter thickness, for a specified maximum emitter temperature. Typical results are presented, and the use of this analysis for predicting the diode operating characteristics is illustrated.

  11. Sighting optics including an optical element having a first focal length and a second focal length

    DOE Patents [OSTI]

    Crandall, David Lynn (Idaho Falls, ID)

    2011-08-01T23:59:59.000Z

    One embodiment of sighting optics according to the teachings provided herein may include a front sight and a rear sight positioned in spaced-apart relation. The rear sight includes an optical element having a first focal length and a second focal length. The first focal length is selected so that it is about equal to a distance separating the optical element and the front sight and the second focal length is selected so that it is about equal to a target distance. The optical element thus brings into simultaneous focus, for a user, images of the front sight and the target.

  12. MODELING LONGITUDINAL DAMAGE IN SHIP COLLISIONS

    E-Print Network [OSTI]

    Brown, Alan

    . Performing Organization Name and Address Department of Aerospace and Ocean Engineering. 10. Work Unit No made excellent progress towards predicting damage penetration in ship collisions. This project focuses collision data for penetrating collisions. 17. Key Words ship collisions, longitudinal ship damage 18

  13. Absorption Lengths in the Holographic Plasma

    E-Print Network [OSTI]

    Irene Amado; Carlos Hoyos; Karl Landsteiner; Sergio Montero

    2007-07-11T23:59:59.000Z

    We consider the effect of a periodic perturbation with frequency $\\omega$ on the holographic N=4 plasma represented by the planar AdS black hole. The response of the system is given by exponentially decaying waves. The corresponding complex wave numbers can be found by solving wave equations in the AdS black hole background with infalling boundary conditions on the horizon in an analogous way as in the calculation of quasinormal modes. The complex momentum eigenvalues have an interpretation as poles of the retarded Green's functions, where the inverse of the imaginary part gives an absorption length $\\lambda$. At zero frequency we obtain the screening length for a static field. These are directly related to the glueball masses in the dimensionally reduced theory. We also point out that the longest screening length corresponds to an operator with non-vanishing R-charge and thus does not have an interpretation as a QCD3 glueball.

  14. Charm and bottom production in inclusive double Pomeron exchange in heavy-ion collisions at energies available at the CERN Large Hadron Collider

    SciTech Connect (OSTI)

    Gay Ducati, M. B.; Machado, M. M.; Machado, M. V. T. [High Energy Physics Phenomenology Group, GFPAE, IF-UFRGS Caixa Postal 15051, CEP 91501-970, Porto Alegre, RS (Brazil)

    2011-01-15T23:59:59.000Z

    The inclusive double Pomeron exchange cross section for heavy-quark pair production is calculated for nucleus-nucleus collisions at the Large Hadron Collider. The present estimate is based on hard diffractive factorization, corrected by absorptive corrections and nuclear effects. The theoretical uncertainties for nuclear collisions are investigated and a comparison to other approaches is presented. The production channels giving a similar final state configuration are discussed as well.

  15. Crystal diffraction lens with variable focal length

    DOE Patents [OSTI]

    Smither, R.K.

    1991-04-02T23:59:59.000Z

    A method and apparatus for altering the focal length of a focusing element of one of a plurality of pre-determined focal lengths by changing heat transfer within selected portions of the element by controlled quantities is disclosed. Control over heat transfer is accomplished by manipulating one or more of a number of variables, including: the amount of heat or cold applied to surfaces; type of fluids pumped through channels for heating and cooling; temperatures, directions of flow and rates of flow of fluids; and placement of channels. 19 figures.

  16. Apparatus for fabricating continuous lengths of superconductor

    DOE Patents [OSTI]

    Kroeger, Donald M. (Knoxville, TN); List, III, Frederick A. (Andersonville, TN)

    2002-01-01T23:59:59.000Z

    A process and apparatus for manufacturing a superconductor. The process is accomplished by depositing a superconductor precursor powder on a continuous length of a first substrate ribbon, overlaying a continuous length of a second substrate ribbon on said first substrate ribbon, and applying sufficient pressure to form a bound layered superconductor comprising a layer of said superconducting precursor powder between said first substrate ribbon and said second substrates ribbon. The layered superconductor is then heat treated to establish the superconducting phase of said superconductor precursor powder.

  17. Apparatus for fabricating continuous lengths of superconductor

    DOE Patents [OSTI]

    Kroeger, Donald M. (Knoxville, TN); List, III, Frederick A. (Andersonville, TN)

    2001-01-01T23:59:59.000Z

    A process and apparatus for manufacturing a superconductor. The process is accomplished by depositing a superconductor precursor powder on a continuous length of a first substrate ribbon, overlaying a continuous length of a second substrate ribbon on said first substrate ribbon, and applying sufficient pressure to form a bound layered superconductor comprising a layer of said superconducting precursor powder between said first substrate ribbon and said second substrates ribbon. The layered superconductor is then heat treated to establish the superconducting phase of said superconductor precursor powder.

  18. Nuclear Physics

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

    Underground Research Facility in South Dakota, which will search for neutrinoless double-beta decay. Strong Los Alamos programs in nuclear data and nuclear theory supports...

  19. EA Systems Examples Induction and Recursion Length Measuring the Universe Analysis Number systems of different lengths,

    E-Print Network [OSTI]

    Forster, T.E.

    EA Systems Examples Induction and Recursion Length Measuring the Universe Analysis Number systems of Mathematics University of Bristol April 21, 2008 Richard.Pettigrew@bris.ac.uk Natural number systems and infinitesimal analysis #12;EA Systems Examples Induction and Recursion Length Measuring the Universe Analysis

  20. Anti-flow of K$^0_s$ Mesons in 6 AGeV Au + Au Collisions

    E-Print Network [OSTI]

    P. Chung; N. N. Ajitanand; J. M. Alexander; M. Anderson; D. Best; F. P. Brady; T. Case; W. Caskey; D. Cebra; J. L. Chance; B. Cole; K. Crowe; A. Das; J. E. Draper; M. L. Gilkes; S. Gushue; M. Heffner; A. S. Hirsch; E. L. Hjort; L. Huo; M. Justice; M. Kaplan; D. Keane; J. C. Kintner; J. Klay; D. Krofcheck; R. A. Lacey; J. Lauret; M. A. Lisa; H. Liu; Y. M. Liu; R. McGrath; Z. Milosevich; G. Odyniec; D. L. Olson; S. Y. Panitkin; C. Pinkenburg; N. T. Porile; G. Rai; H. G. Ritter; J. L. Romero; R. Scharenberg; L. Schroeder; B. Srivastava; N. T. BStone; T. J. M. Symons; T. Wienold; R. Witt J. Whitfield; L. Wood; W. N. Zhang

    2001-01-06T23:59:59.000Z

    We have measured the sideward flow of neutral strange ($K^0_s$) mesons in 6 AGeV Au + Au collisions. A prominent anti-flow signal is observed for an impact parameter range (b $\\lesssim 7$ fm) which spans central and mid-central events. Since the $K^0_s$ scattering cross section is relatively small in nuclear matter, this observation suggests that the in-medium kaon vector potential plays an important role in high density nuclear matter.

  1. Subthreshold Production of Kaons and Antikaons in Nucleus-Nucleus Collisions at Equivalent Beam Energies

    SciTech Connect (OSTI)

    Barth, R.; Senger, P.; Ahner, W.; Debowski, M.; Grosse, E.; Koczon, P.; Miskowiec, D.; Schwab, E.; Schicker, R. [Gesellschaft fuer Schwerionenforschung, D-64220 Darmstadt (Germany)] [Gesellschaft fuer Schwerionenforschung, D-64220 Darmstadt (Germany); Muentz, C.; Oeschler, H.; Sturm, C.; Wagner, A. [Technische Hochschule Darmstadt, D-64289 Darmstadt (Germany)] [Technische Hochschule Darmstadt, D-64289 Darmstadt (Germany); Beckerle, P.; Bormann, C.; Brill, D.; Schwab, E.; Shin, Y.; Stroebele, H. [Johann Wolfgang Goethe Universitaet, D-60325 Frankfurt am Main (Germany)] [Johann Wolfgang Goethe Universitaet, D-60325 Frankfurt am Main (Germany); Kohlmeyer, B.; Puehlhofer, F.; Speer, J.; Voelkel, K. [Phillips Universitaet, D-35037 Marburg (Germany)] [Phillips Universitaet, D-35037 Marburg (Germany); Cieslak, M.; Walus, W. [Jagiellonian University, PL-30-059 Krakow (Poland)] [Jagiellonian University, PL-30-059 Krakow (Poland)

    1997-05-01T23:59:59.000Z

    Kaon production has been studied in Ni+Ni collisions at beam energies of 0.8{endash}1.8GeV/nucleon with the kaon spectrometer at GSI. The K{sup +} production cross section increases as E{sup 5.3{plus_minus}0.2}{sub beam} . Both K{sup +} and K{sup -} mesons are predominantly produced in central collisions. The K{sup -}/K{sup +} ratio measured at equivalent beam energies below the respective particle production threshold is considerably larger for Ni+Ni collisions than for nucleon-nucleon collisions near threshold. This is evidence for an enhanced K{sup -} production in the nuclear medium. {copyright} {ital 1997} {ital The American Physical Society}

  2. Forward hadron production in ultraperipheral proton-heavy-ion collisions at the LHC and RHIC

    E-Print Network [OSTI]

    Mitsuka, Gaku

    2015-01-01T23:59:59.000Z

    We discuss hadron production in the forward rapidity region in ultraperipheral proton-lead collisions at the LHC and proton-gold collisions at RHIC. Our discussion is based on the Monte Carlo simulations of the interactions of virtual photons emitted by a fast moving nucleus with a proton beam. We simulate the virtual photon flux with the STARLIGHT event generator and then particle production with the SOPHIA, DPMJET, and PYTHIA event generators. We show the rapidity distributions of charged and neutral particles, and the momentum distributions of neutral pions and neutrons at forward rapidities. According to the Monte Carlo simulations, we find large cross sections of ultraperipheral collisions for particle production especially in the very forward region, leading to substantial background contributions to investigations of collective nuclear effects and spin physics. Finally we can distinguish between proton-nucleus inelastic interactions and ultraperipheral collisions with additional requirements of either ...

  3. Avoiding character collisions in games

    E-Print Network [OSTI]

    Calderon, Manuel

    1999-01-01T23:59:59.000Z

    that solves this problem for situations with at least thirty characters. A program was written to test and demonstrate the method. This method might also contribute to the solution of collision avoidance problems in robotics....

  4. Jet measurements in proton-proton collisions with the ALICE experiment at LHC

    E-Print Network [OSTI]

    Michal Vajzer

    2013-01-13T23:59:59.000Z

    The study of jets, collimated sprays of particles associated with hard partons, is an important tool in testing perturbative quantum chromodynamics (pQCD) and probing hot and dense nuclear matter created in high energy heavy-ion collisions. Jets enable the study of hard scatterings, fragmentation and hadronisation and their modification in the presence of a nuclear medium with respect to baseline vacuum measurements, which is acquired from jet measurements in proton-proton collisions. We have analysed data from proton-proton collisions at s= \\sqrt{s} = 7 TeV measured by the ALICE experiment at the LHC and reconstructed the inclusive spectra of charged particle jets at mid- rapidity using anti-kT clustering algorithm. We present the jet spectra corrected for detector effects using several unfolding methods. Furthermore, we examine various properties of jets, such as their charged particle multiplicity and jet shapes.

  5. Estimate of the single diffractive heavy quark production in heavy ion collisions at the CERN LHC

    SciTech Connect (OSTI)

    Gay Ducati, M. B.; Machado, M. M. [High Energy Physics Phenomenology Group, GFPAE, IF-UFRGS, Caixa Postal 15051, CEP 91501-970, Porto Alegre, RS (Brazil); Machado, M. V. T. [Universidade Federal do Pampa. Centro de Ciencias Exatas e Tecnologicas, Campus de Bage, Rua Carlos Barbosa. CEP 96400-970. Bage, RS (Brazil)

    2010-03-01T23:59:59.000Z

    The single diffractive cross section for heavy quarks production is calculated at next-to-leading order (for nucleus-nucleus collisions. Such processes are expected to occur at the LHC, where the nuclei involved are lead at {radical}(s)=5.5 TeV and calcium at {radical}(s)=6.3 TeV. We start using the hard diffractive factorization formalism, taking into account a recent experimental parametrization for the Pomeron structure function (DPDF). Absorptive corrections are accounted for by the multiple Pomeron contributions considering a gap survival probability, where its theoretical uncertainty for nuclear collisions is discussed. We estimate the diffractive ratios for the single diffraction process in nuclear coherent/incoherent collisions at the LHC.

  6. Nuclear weapons and nuclear war

    SciTech Connect (OSTI)

    Cassel, C.; McCally, M.; Abraham, H.

    1984-01-01T23:59:59.000Z

    This book examines the potential radiation hazards and environmental impacts of nuclear weapons. Topics considered include medical responsibility and thermonuclear war, the threat of nuclear war, nuclear weaponry, biological effects, radiation injury, decontamination, long-term effects, ecological effects, psychological aspects, the economic implications of nuclear weapons and war, ethics, civil defense, arms control, nuclear winter, and long-term biological consequences of nuclear war.

  7. Jet studies 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

    2011-06-17T23:59:59.000Z

    Recent progress in full jet reconstruction in heavy-ion collisions at RHIC makes it a promising tool for the quantitative study of the QCD at high energy density. Measurements in d+Au collisions are important to disentangle initial state nuclear effects from medium-induced k_T broadening and jet quenching. Furthermore, comparison to measurements in p+p gives access to cold nuclear matter effects. Inclusive jet p_T spectra and di-jet correlations (k_T) in 200 GeV p+p and d+Au collisions from the 2007-2008 RHIC run are presented.

  8. Nuclear Matter and Nuclear Dynamics

    E-Print Network [OSTI]

    M Colonna

    2009-02-26T23:59:59.000Z

    Highlights on the recent research activity, carried out by the Italian Community involved in the "Nuclear Matter and Nuclear Dynamics" field, will be presented.

  9. Jet tomography of AA-collisions at RHIC and LHC energies

    E-Print Network [OSTI]

    Zakharov, B G

    2013-01-01T23:59:59.000Z

    We present our recent results on jet tomography of AA-collisions at RHIC and LHC. We focus on flavor dependence of the nuclear modification factor. The computations are performed accounting for radiative and collisional parton energy loss with running coupling constant.

  10. Jet and Leading Hadron Production in High-energy Heavy-ion Collisions

    E-Print Network [OSTI]

    Xin-Nian Wang

    2005-10-31T23:59:59.000Z

    Jet tomography has become a powerful tool for the study of properties of dense matter in high-energy heavy-ion collisions. I will discuss recent progresses in the phenomenological study of jet quenching, including momentum, colliding energy and nuclear size dependence of single hadron suppression, modification of dihadron correlations and the soft hadron distribution associated with a quenched jet.

  11. Pauling bond strength, bond length and electron density distribution...

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

    Pauling bond strength, bond length and electron density distribution. Pauling bond strength, bond length and electron density distribution. Abstract: A power law regression...

  12. Two-pion Bose-Einstein correlations in pp collisions at sqrt(s)=900 GeV

    E-Print Network [OSTI]

    K. Aamodt; N. Abel; U. Abeysekara; A. Abrahantes Quintana; A. Abramyan; D. Adamova; M. M. Aggarwal; G. Aglieri Rinella; A. G. Agocs; S. Aguilar Salazar; Z. Ahammed; A. Ahmad; N. Ahmad; S. U. Ahn; R. Akimoto; A. Akindinov; D. Aleksandrov; B. Alessandro; R. Alfaro Molina; A. Alici; E. Almaraz Avina; J. Alme; T. Alt; V. Altini; S. Altinpinar; C. Andrei; A. Andronic; G. Anelli; V. Angelov; C. Anson; T. Anticic; F. Antinori; S. Antinori; K. Antipin; D. Antonczyk; P. Antonioli; A. Anzo; L. Aphecetche; H. Appelshauser; S. Arcelli; R. Arceo; A. Arend; N. Armesto; R. Arnaldi; T. Aronsson; I. C. Arsene; A. Asryan; A. Augustinus; R. Averbeck; T. C. Awes; J. Aysto; M. D. Azmi; S. Bablok; M. Bach; A. Badala; Y. W. Baek; S. Bagnasco; R. Bailhache; R. Bala; A. Baldisseri; A. Baldit; J. Ban; R. Barbera; G. G. Barnafoldi; L. S. Barnby; V. Barret; J. Bartke; F. Barile; M. Basile; V. Basmanov; N. Bastid; B. Bathen; G. Batigne; B. Batyunya; C. Baumann; I. G. Bearden; B. Becker; I. Belikov; R. Bellwied; E. Belmont-Moreno; A. Belogianni; L. Benhabib; S. Beole; I. Berceanu; A. Bercuci; E. Berdermann; Y. Berdnikov; L. Betev; A. Bhasin; A. K. Bhati; L. Bianchi; N. Bianchi; C. Bianchin; J. Bielcik; J. Bielcikova; A. Bilandzic; L. Bimbot; E. Biolcati; A. Blanc; F. Blanco; F. Blanco; D. Blau; C. Blume; M. Boccioli; N. Bock; A. Bogdanov; H. Boggild; M. Bogolyubsky; J. Bohm; L. Boldizsar; M. Bombara; C. Bombonati; M. Bondila; H. Borel; A. Borisov; C. Bortolin; S. Bose; L. Bosisio; F. Bossu; M. Botje; S. Bottger; G. Bourdaud; B. Boyer; M. Braun; P. Braun-Munzinger; L. Bravina; M. Bregant; T. Breitner; G. Bruckner; R. Brun; E. Bruna; G. E. Bruno; D. Budnikov; H. Buesching; P. Buncic; O. Busch; Z. Buthelezi; D. Caffarri; X. Cai; H. Caines; E. Calvo; E. Camacho; P. Camerini; M. Campbell; V. Canoa Roman; G. P. Capitani; G. Cara Romeo; F. Carena; W. Carena; F. Carminati; A. Casanova Diaz; M. Caselle; J. Castillo Castellanos; J. F. Castillo Hernandez; V. Catanescu; E. Cattaruzza; C. Cavicchioli; P. Cerello; V. Chambert; B. Chang; S. Chapeland; A. Charpy; J. L. Charvet; S. Chattopadhyay; S. Chattopadhyay; M. Cherney; C. Cheshkov; B. Cheynis; E. Chiavassa; V. Chibante Barroso; D. D. Chinellato; P. Chochula; K. Choi; M. Chojnacki; P. Christakoglou; C. H. Christensen; P. Christiansen; T. Chujo; F. Chuman; C. Cicalo; L. Cifarelli; F. Cindolo; J. Cleymans; O. Cobanoglu; J. -P. Coffin; S. Coli; A. Colla; G. Conesa Balbastre; Z. Conesa del Valle; E. S. Conner; P. Constantin; G. Contin; J. G. Contreras; Y. Corrales Morales; T. M. Cormier; P. Cortese; I. Cortes Maldonado; M. R. Cosentino; F. Costa; M. E. Cotallo; E. Crescio; P. Crochet; E. Cuautle; L. Cunqueiro; J. Cussonneau; A. Dainese; H. H. Dalsgaard; A. Danu; I. Das; A. Dash; S. Dash; G. O. V. de Barros; A. De Caro; G. de Cataldo; J. de Cuveland; A. De Falco; M. De Gaspari; J. de Groot; D. De Gruttola; N. De Marco; S. De Pasquale; R. De Remigis; R. de Rooij; G. de Vaux; H. Delagrange; Y. Delgado; G. Dellacasa; A. Deloff; V. Demanov; E. Denes; A. Deppman; G. D'Erasmo; D. Derkach; A. Devaux; D. Di Bari; C. Di Giglio; S. Di Liberto; A. Di Mauro; P. Di Nezza; M. Dialinas; L. Diaz; R. Diaz; T. Dietel; R. Divia; O. Djuvsland; V. Dobretsov; A. Dobrin; T. Dobrowolski; B. Donigus; I. Dominguez; D. M. M. Don; O. Dordic; A. K. Dubey; J. Dubuisson; L. Ducroux; P. Dupieux; A. K. Dutta Majumdar; M. R. Dutta Majumdar; D. Elia; D. Emschermann; A. Enokizono; B. Espagnon; M. Estienne; S. Esumi; D. Evans; S. Evrard; G. Eyyubova; C. W. Fabjan; D. Fabris; J. Faivre; D. Falchieri; A. Fantoni; M. Fasel; O. Fateev; R. Fearick; A. Fedunov; D. Fehlker; V. Fekete; D. Felea; B. Fenton-Olsen; G. Feofilov; A. Fernandez Tellez; E. G. Ferreiro; A. Ferretti; R. Ferretti; M. A. S. Figueredo; S. Filchagin; R. Fini; F. M. Fionda; E. M. Fiore; M. Floris; Z. Fodor; S. Foertsch; P. Foka; S. Fokin; F. Formenti; E. Fragiacomo; M. Fragkiadakis; U. Frankenfeld; A. Frolov; U. Fuchs; F. Furano; C. Furget; M. Fusco Girard; J. J. Gaardhoje; S. Gadrat; M. Gagliardi; A. Gago; M. Gallio; P. Ganoti; M. S. Ganti; C. Garabatos; C. Garcia Trapaga; J. Gebelein; R. Gemme; M. Germain; A. Gheata; M. Gheata; B. Ghidini; P. Ghosh; G. Giraudo; P. Giubellino; E. Gladysz-Dziadus; R. Glasow; P. Glassel; A. Glenn; R. Gomez Jimenez; H. Gonzalez Santos; L. H. Gonzalez-Trueba; P. Gonzalez-Zamora; S. Gorbunov; Y. Gorbunov; S. Gotovac; H. Gottschlag; V. Grabski; R. Grajcarek; A. Grelli; A. Grigoras; C. Grigoras; V. Grigoriev; A. Grigoryan; S. Grigoryan; B. Grinyov; N. Grion; P. Gros; J. F. Grosse-Oetringhaus; J. -Y. Grossiord; R. Grosso; F. Guber; R. Guernane; C. Guerra; B. Guerzoni; K. Gulbrandsen; H. Gulkanyan; T. Gunji; A. Gupta; R. Gupta; H. -A. Gustafsson; H. Gutbrod; O. Haaland; C. Hadjidakis; M. Haiduc; H. Hamagaki; G. Hamar; J. Hamblen; B. H. Han; J. W. Harris; M. Hartig; A. Harutyunyan; D. Hasch

    2010-07-03T23:59:59.000Z

    We report on the measurement of two-pion correlation functions from pp collisions at sqrt(s)=900 GeV performed by the ALICE experiment at the Large Hadron Collider. Our analysis shows an increase of the HBT radius with increasing event multiplicity, in line with other measurements done in particle- and nuclear collisions. Conversely, the strong decrease of the radius with increasing transverse momentum, as observed at RHIC and at Tevatron, is not manifest in our data.

  13. Reaction product characteristics of the 65Cu+232Th violent collision at 35MeV/nucleon

    SciTech Connect (OSTI)

    Majka, Z.; Cibor, J.; Kozik, T. [Jagellonian Univ., Krakow (Poland)] [and others

    1995-12-01T23:59:59.000Z

    An exclusive experiment that imposed strong restrictive conditions has been performed at the Texas A&M K-500 superconducting cyclotron facility to study the formation and decay of hot nuclear system in the 35 AMeV 63Cu+232Th collision. Dynamical aspects of the collision between the projectile and target were simulated by the computer code CHIMERA which is based on the molecular dynamics concept.

  14. Temperature of projectile like fragments in heavy ion collisions

    E-Print Network [OSTI]

    Gupta, S Das; Chaudhuri, G

    2013-01-01T23:59:59.000Z

    A model in which a projectile like fragment can be simply regarded as a remnant after removal of some part of the projectile leads to an excited fragment. This excitation energy can be calculated with a Hamiltonian that gives correct nuclear matter binding, compressibility and density distribution in finite nuclei. In heavy ion collisions the model produces a dependence of excitation energy on impact parameter which appears to be correct but the magnitude of the excitation energy falls short. It is argued that dynamic effects left out in the model will increase this magnitude. The model can be directly extended to include dynamics but at the expense of increased computation. For many calculations for observables, a temperature is an easier tool to use rather than an excitation energy. Hence temperature dependences on impact parameter in heavy ion collisions are displayed.

  15. Temperature of projectile like fragments in heavy ion collisions

    E-Print Network [OSTI]

    S. Das Gupta; S. Mallik; G. Chaudhuri

    2013-09-27T23:59:59.000Z

    A model in which a projectile like fragment can be simply regarded as a remnant after removal of some part of the projectile leads to an excited fragment. This excitation energy can be calculated with a Hamiltonian that gives correct nuclear matter binding, compressibility and density distribution in finite nuclei. In heavy ion collisions the model produces a dependence of excitation energy on impact parameter which appears to be correct but the magnitude of the excitation energy falls short. It is argued that dynamic effects left out in the model will increase this magnitude. The model can be directly extended to include dynamics but at the expense of increased computation. For many calculations for observables, a temperature is an easier tool to use rather than an excitation energy. Hence temperature dependences on impact parameter in heavy ion collisions are displayed.

  16. New hydrocracking catalysts increase throughput, run length

    SciTech Connect (OSTI)

    Huizinga, T. [Shell Internationale Petroleum Mij., The Hague (Netherlands); Theunissen, J.M.H. [Rayong Refinery Co. Ltd., Rayong (Thailand); Minderhoud, H.; Veen, R. van [Koninklijke/Shell-Lab., Amsterdam (Netherlands)

    1995-06-26T23:59:59.000Z

    An improved, second-stage hydrocracking catalyst has been developed by combining stabilized Y zeolites with amorphous silica alumina cracking components. A commercial application of this catalyst, along with a new, first-stage zeolitic hydrocracking catalyst, resulted in increased unit throughput and cycle length. The paper discusses the hydrocracking process, first-stage catalysts, second-stage catalysts, hydrogenation process, commercial results, and product properties.

  17. Pairing Effects in Nuclear Fusion Reaction

    E-Print Network [OSTI]

    Shuichiro Ebata; Takashi Nakatsukasa

    2013-09-29T23:59:59.000Z

    We simulate a heavy-ion collision using the canonical-basis time-dependent Hartree-Fock-Bogoliubov theory (Cb-TDHFB) treating pairing correlation in the three-dimensional coordinate space. We apply the Cb-TDHFB to 22O+22O collision with a contact-type pairing energy functional, and compare results of Cb-TDHFB and TDHF to investigate the effects of pairing correlations in nuclear fusion. Our results seem to indicate that pairing effects do not increase the fusion cross section in this system.

  18. Measurement of jet $p_{\\rm T}$ spectra and $R_{\\rm AA}$ in pp and Pb-Pb collisions at $\\sqrt{s_{\\rm NN}}$ = 2.76 TeV with the ALICE detector

    E-Print Network [OSTI]

    Salvatore Aiola; for the ALICE Collaboration

    2014-12-08T23:59:59.000Z

    Hard-scattered partons provide an ideal probe for the study of the Quark-Gluon Plasma because they are produced prior to the formation of the QCD medium in heavy-ion collisions. Jet production is therefore susceptible to modifications induced by the presence of the medium ("jet quenching"). Both RHIC and LHC experiments have provided compelling evidence of jet quenching. Jets are reconstructed in ALICE utilizing the central tracking system for the charged constituents and the Electromagnetic Calorimeter for the neutral constituents. Jet spectra are reported for central (0-10%) and semi-central (10-30%) Pb-Pb events at $\\sqrt{s_{\\rm NN}}=2.76$ TeV. The nuclear modification factor, determined using a pp baseline measured at the same collisional energy, shows a strong suppression of jet production in central Pb-Pb collisions with the expected centrality ordering. Observations are in qualitative agreement with medium-induced energy loss models. Furthermore, indication of a path-length dependence of jet suppression is inferred from measurements of the yields relative to the orientation of the event plane.

  19. Length and Energy of Quadratic Bezier Curves and Applications

    E-Print Network [OSTI]

    Hoffmann, Christoph M.

    Length and Energy of Quadratic B´ezier Curves and Applications Young Joon Ahn a , Christoph for the arc length and the bending energy of quadratic B´ezier curves. The formulae are in terms control point is analyzed for curves of fixed arc length or bending energy. In the case of arc length

  20. Nuclear Resonance Fluorescence for Nuclear Materials Assay

    E-Print Network [OSTI]

    Quiter, Brian Joseph

    2010-01-01T23:59:59.000Z

    to Journal of Nuclear Technology. [46] C.J. Hagmann and J.Library for Nuclear Science and Technology,” Nuclear Dataof Standards and Technology daughter nuclear data processing

  1. Nuclear reactor safety device

    DOE Patents [OSTI]

    Hutter, E.

    1983-08-15T23:59:59.000Z

    A safety device is described for use in a nuclear reactor for axially repositioning a control rod with respect to the reactor core in the event of a thermal excursion. It comprises a laminated strip helically configured to form a tube, said tube being in operative relation to said control rod. The laminated strip is formed of at least two materials having different thermal coefficients of expansion, and is helically configured such that the material forming the outer lamina of the tube has a greater thermal coefficient of expansion than the material forming the inner lamina of said tube. In the event of a thermal excursion the laminated strip will tend to curl inwardly so that said tube will increase in length, whereby as said tube increases in length it exerts a force on said control rod to axially reposition said control rod with respect to said core.

  2. {phi} meson production in Au + Au and p + p collisions at {radical}s{sub NN}=200 GeV

    SciTech Connect (OSTI)

    Adams, J.; Adler, C.; Aggarwal, M.M.; Ahammed, Z.; Amonett, J.; Anderson, B.D.; Arkhipkin, D.; Averichev, G.S.; Badyal, S.K.; Balewski, J.; Barannikova, O.; Barnby, L.S.; Baudot, J.; Bekele, S.; Belaga, V.V.; Bellwied, R.; Berger, J.; Bezverkhny, B.I.; Bhardwaj, S.; Bhati, A.K.; Bichsel, H.; Billmeier, A.; Bland, L.C.; Blyth, C.O.; Bonner, B.E.; Botje, M.; Boucham, A.; Brandin, A.; Bravar, A.; Cadman, R.V.; Cai, X.Z.; Caines, H.; Calderon de la Barca Sanchez, M.; Carroll, J.; Castillo, J.; Cebra, D.; Chaloupka, P.; Chattopadhyay, S.; Chen, H.F.; Chen, Y.; Chernenko, S.P.; Cherney, M.; Chikanian, A.; Christie, W.; Coffin, J.P.; Cormier, T.M.; Cramer, J.G.; Crawford, H.J.; Das, D.; Das, S.; Derevschikov, A.A.; Didenko, L.; Dietel, T.; Dong, W.J.; Dong, X.; Draper, J.E.; Du, F.; Dubey, A.K.; Dunin, V.B.; Dunlop, J.C.; Dutta Majumdar, M.R.; Eckardt, V.; Efimov, L.G.; Emelianov, V.; Engelage, J.; Eppley, G.; Erazmus, B.; Estienne, M.; Fachini, P.; Faine, V.; Faivre, J.; Fatemi, R.; Filimonov, K.; Filip, P.; Finch, E.; Fisyak, Y.; Flierl, D.; Foley, K.J.; Fu, J.; Gagliardi, C.A.; Gagunashvili, N.; Gans, J.; Ganti, M.S.; Gaudichet, L.; Germain, M.; Geurts, F.; Ghazikhanian, V.; Ghosh, P.; Gonzalez, J.E.; Grachov, O.; Grebenyuk, O.; Gronstal, S.; Grosnick, D.; Guedon, M.; Guertin, S.M.; Gupta, A.; Gutierrez, T.D.; Hallman, T.J.; Hamed, A.; Hardtke, D.; Harris, J.W.; Heinz, M.; Henry, T.W.; Heppelmann, S.; Hippolyte, B.; Hirsch, A.; Hjort, E.; Hoffmann, G.W.; Horsley, M.; Huang, H.Z.; Huang, S.L.; Hughes, E.; Humanic, T.J.; Igo, G.; Ishihara, A.; Jacobs, P.; Jacobs, W.W.; Janik, M.; Johnson, I.; Jones, P.G.; Judd, E.G.; Kabana, S.; Kaplan, M.; Keane, D.; Khodyrev; Kiryluk, J.; Kisiel, A.; Klay, J.; Klein, S.R.; Klyachko, A.; Koetke, D.D.; Kollegger, T.; Kopytine, S.M.; Kotchenda, L.; Kovalenko, A.D.; Kramer, M.; Kravtsov, P.; Kravstov, V.I.; Krueger, K.; Kuhn, C.; Kulikov, A.I.; Kumar, A.; Kunde, G.J.; Kunz, C.L.; Kutuev, R.Kh.; et al.

    2004-06-01T23:59:59.000Z

    We report the STAR measurement of {psi} meson production in Au + Au and p + p collisions at {radical}s{sub NN} = 200 GeV. Using the event mixing technique, the {psi} spectra and yields are obtained at midrapidity for five centrality bins in Au+Au collisions and for non-singly-diffractive p+p collisions. It is found that the {psi} transverse momentum distributions from Au+Au collisions are better fitted with a single-exponential while the p+p spectrum is better described by a double-exponential distribution. The measured nuclear modification factors indicate that {psi} production in central Au+Au collisions is suppressed relative to peripheral collisions when scaled by the number of binary collisions (). The systematics of versus centrality and the constant {psi}/K{sup -} ratio versus beam species, centrality, and collision energy rule out kaon coalescence as the dominant mechanism for {psi} production.

  3. Subthreshold Antiproton Production in Nucleus-Nucleus Collisions

    E-Print Network [OSTI]

    Ko, Che Ming; Xia, L. H.

    1989-01-01T23:59:59.000Z

    77843 (Received 17 May 1989) Antiproton production from the secondary process pp~ pp is studied for nucleus-nucleus col- lisions at energies which are below the threshold for its production from the nucleon-nucleon reac- tion in the free space... of the Dirac sea in the presence of dense nuclear matter. The measured antiproton to negative pion ratio for the collision of two Si nuclei at an incident energy of 2. 1 GeV/nucleon has a surprisingly large value of about 4.3x10 . This is 3 orders...

  4. TREKisM At Length Issue 2

    E-Print Network [OSTI]

    Multiple Contributors

    1981-01-01T23:59:59.000Z

    . "Triskelian Fledgeling" — by Vel Jaeger "Kelvan Exile" — by Vel Jaeger 111. Romulan Astronomy — by Robert S. Sayes 113c Trek-M's Speak their Minds on ST:TMP 121. A Glance Backwards - reactions to TaL I (first issue of TREKisM at Length) 122. Trivia Quizes #3...\\un Speck run. "fynjrur^run. -Storu Ipu1- 'The^dds" UYena T^fc* Ink.nc l'*- bjj rafrick La\\fena ^aq Kidd LuckICKU ©/980' -14- 0N CONVENTIONAL OCCASIONS The following Is a conglomeration of reports, Interviews, and reminiscences from TREKisM members...

  5. TREKiSM At Length Issue 5

    E-Print Network [OSTI]

    Multiple Contributors

    1988-01-01T23:59:59.000Z

    Trek IV! SHALOM PAX PEACE to us all in 1986 Table of Contents TITLE AUTHOR ARTIST PAGE I. DATA ENTRIES FROST ON THE TYPEWRITER V.L. Thorn LaVena Kay Kldd 2 "Trek Omen" V.L. Thorn 6 (originally appeared In TREKisM #26) JAMES T. KIRK vs THE COMPUTER... appeared in TREKisM at Length III) TALES FROM THE VULCAN HEARTH Karen C. Hunter 53 HOW THE VULCANS LOST THEIR WINGS 54 THE SKY GOD'S DAUGHTER 56 THE GIFT OF THE GODS LaVena Kay Kldd 57 "Sul Generis" V.L. Thorn 58 "Cat-Kin" Emily Ross 60 (originally appeared...

  6. Property:Length (m) | Open Energy Information

    Open Energy Info (EERE)

    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 Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov YouKizildere I Geothermal PwerPerkins County, Nebraska:PrecourtOid JumpEligSysSize JumpTechDsc JumpAlpha3 JumpLabLength (m)

  7. Event characterization in (very) asymmetric collisions

    E-Print Network [OSTI]

    G. David

    2014-09-24T23:59:59.000Z

    Event-by-event reconstruction of the collision geometry using some incarnation of the Glauber-model is a widely accepted method in studying heavy ion collisions. While there is no known problem with the procedure when applied to the collision of two large ions, we will argue that in very asymmetric collisions, like $p(d)$+A with at least one hard scattering process occuring the event geometry deduced with the simple Glauber-model may be biased.

  8. Diffractive bremsstrahlung in hadronic collisions

    E-Print Network [OSTI]

    Pasechnik, Roman; Potashnikova, Irina

    2015-01-01T23:59:59.000Z

    Production of heavy photons (Drell-Yan), gauge bosons, Higgs bosons, heavy flavors, which is treated within the QCD parton model as a result of hard parton-parton collision, can be considered as a bremsstrahlung process in the target rest frame. In this review, we discuss the basic features of the diffractive channels of these processes in the framework of color dipole approach. The main observation is a dramatic breakdown of diffractive QCD factorisation due to the interplay between soft and hard interactions, which dominates these processes. This observation is crucial for phenomenological studies of diffractive reactions in high-energy hadronic collisions.

  9. Nuclear reactor reflector

    DOE Patents [OSTI]

    Hopkins, Ronald J. (Pensacola, FL); Land, John T. (Pensacola, FL); Misvel, Michael C. (Pensacola, FL)

    1994-01-01T23:59:59.000Z

    A nuclear reactor reflector is disclosed that comprises a stack of reflector blocks with vertical water flow passages to cool the reflector. The interface between blocks is opposite support points for reactor fuel rods. Water flows between the reflector and the reactor barrel from passages in a bottom block. The top block contains a flange to limit this flow and the flange has a slot to receive an alignment pin that is welded to the barrel. The pin is held in the slot by two removable shims. Alignment bars extend the length of the stack in slots machined in each block when the stack is assembled.

  10. Nuclear reactor reflector

    DOE Patents [OSTI]

    Hopkins, R.J.; Land, J.T.; Misvel, M.C.

    1994-06-07T23:59:59.000Z

    A nuclear reactor reflector is disclosed that comprises a stack of reflector blocks with vertical water flow passages to cool the reflector. The interface between blocks is opposite support points for reactor fuel rods. Water flows between the reflector and the reactor barrel from passages in a bottom block. The top block contains a flange to limit this flow and the flange has a slot to receive an alignment pin that is welded to the barrel. The pin is held in the slot by two removable shims. Alignment bars extend the length of the stack in slots machined in each block when the stack is assembled. 12 figs.

  11. Nuclear Engineer

    Broader source: Energy.gov [DOE]

    This position is located in the Nuclear Safety Division which has specific responsibility for managing the development, analysis, review, and approval of non-reactor nuclear facility safety bases...

  12. Nuclear Navy

    SciTech Connect (OSTI)

    Not Available

    1994-01-01T23:59:59.000Z

    This video tells the story of the Navy's development of nuclear power and its application in long-range submarines and the growing nuclear surface force. Narrated by Frank Blair.

  13. Nuclear Navy

    SciTech Connect (OSTI)

    NONE

    1994-12-31T23:59:59.000Z

    This video tells the story of the Navy`s development of nuclear power and its application in long-range submarines and the growing nuclear surface force. Narrated by Frank Blair.

  14. Nuclear Engineer

    Broader source: Energy.gov [DOE]

    This position is located in the Nuclear Safety Division (NSD) which has specific responsibility for managing the development, analysis, review, and approval of non-reactor nuclear facility safety...

  15. Gamma-radiation as a Signature of Ultra Peripheral Ion Collisions at LHC energies

    E-Print Network [OSTI]

    Yu. V. Kharlov; V. L. Korotkikh

    2004-01-13T23:59:59.000Z

    We study the peripheral ion collisions at LHC energies in which a nucleus is excited to the discrete state and then emits $\\gamma$-rays. Large nuclear Lorenz factor allows to observe the high energy photons up to a few ten GeV and in the region of angles of a few hundred micro-radians around the beam direction. These photons can be used for tagging the events with particle production in the central rapidity region in the ultra-peripheral collisions. For that it is necessary to have an electromagnetic detector in front of the zero degree calorimeter in the LHC experiments.

  16. New isospin e ffects in central heavy-ion collisions at Fermi energies

    E-Print Network [OSTI]

    F. Gagnon-Moisan; E. Galichet; M. -F. Rivet; B. Borderie; M. Colonna; R. Roy; G. Ademard; M. Boisjoli; E. Bonnet; R. Bougault; A. Chbihi; J. D. Frankland; D. Guinet; P. Lautesse; E. Legou ee; N. Le Neindre; L. Manduci; P. Marini; P. Napolitani; M. Pârlog; P. Pawlowski; E. Rosato; M. Vigilante

    2012-09-28T23:59:59.000Z

    Isospin e ffects on multifragmentation properties were studied thanks to nuclear collisions between di fferent isotopes of xenon beams and tin targets. It is shown that, in central collisions leading to multifragmentation, the mean number of fragments and their mean kinetic energy increase with the neutron-richness of the total system. Comparisons with a stochastic transport model allow to attribute the multiplicity increase to the multifragmentation stage, before secondary decay. The total charge bound in fragments is proposed as an alternate variable to quantify preequilibrium emission and to investigate symmetry energy e ffects.

  17. Scaling patterns for the suppression of charged hadron yields in Pb+Pb collisions at Root_s = 2.76 TeV: Constraints on transport coefficients

    E-Print Network [OSTI]

    Roy A. Lacey; N. N. Ajitanand; J. M. Alexander; J. Jia; A. Taranenko

    2012-02-24T23:59:59.000Z

    Suppression measurements for charged hadrons are used to investigate the path length (L) and transverse momentum (p_T) dependent jet quenching patterns of the hot and dense QCD medium produced in Pb+Pb collisions at Root_s =2.76 TeV at the LHC. The observed scaling patterns, which are similar to those observed for Au+Au collisions at Root_s = 0.20 TeV at RHIC, show the trends predicted for jet-medium interactions dominated by radiative energy loss. They also allow a simple estimate of the transport coefficient $\\hat{q}$, which suggests that the medium produced in LHC collisions is somewhat less opaque than that produced at RHIC, if the same parton-medium coupling strength is assumed. The higher temperature produced in LHC collisions could reduce the parton-medium coupling strength to give identical values for $\\hat{q}$ in LHC and RHIC collisions.

  18. Pion Interferometry in Au+Au and Cu+Cu Collisions at sqrt sNN = 62.4 and 200 GeV

    SciTech Connect (OSTI)

    STAR Collaboration; Abelev, B.I.

    2009-08-24T23:59:59.000Z

    We present a systematic analysis of two-pion interferometry in Au+Au collisions at {radical}sNN = 62.4 GeV and Cu+Cu collisions at {radical}sNN = 62.4 and 200 GeV using the STAR detector at RHIC. The multiplicity and transverse momentum dependences of the extracted correlation lengths (radii) are studied. The scaling with charged particle multiplicity of the apparent system volume at final interaction is studied for the RHIC energy domain. The multiplicity scaling of the measured correlation radii is found to be independent of colliding system and collision energy.

  19. Nuclear weapons, nuclear effects, nuclear war

    SciTech Connect (OSTI)

    Bing, G.F.

    1991-08-20T23:59:59.000Z

    This paper provides a brief and mostly non-technical description of the militarily important features of nuclear weapons, of the physical phenomena associated with individual explosions, and of the expected or possible results of the use of many weapons in a nuclear war. Most emphasis is on the effects of so-called ``strategic exchanges.``

  20. Interception of comets and asteroids on collision course with earth

    SciTech Connect (OSTI)

    Solem, J.C.

    1992-03-01T23:59:59.000Z

    I derive expressions for the weight and range of applicability of interceptors capable of deflecting a comet or asteroid on collision course with Earth. The expressions use a fairly general relationship between the energy deposited and the mass of material blown off the astral assailant. To assess the probability that the astral assailant will fracture, I also calculate the fraction of the astral assailant`s mass that will be blown off. The interaction is calculated for both kinetic-energy deflection and nuclear-explosive deflection. In the nuclear-explosive case, I calculate the interceptor mass and cratering effect for detonations above the surface and below the surface as well as directly on the surface of the astral assailant. Because the wide range of densities and material properties that the astral assailant may possess, the principal value of this work is to show the relationships among the salient parameters of the problem.

  1. Interception of comets and asteroids on collision course with earth

    SciTech Connect (OSTI)

    Solem, J.C.

    1992-01-01T23:59:59.000Z

    I derive expressions for the weight and range of applicability of interceptors capable of deflecting a comet or asteroid on collision course with Earth. The expressions use a fairly general relationship between the energy deposited and the mass of material blown off the astral assailant. To assess the probability that the astral assailant will fracture, I also calculate the fraction of the astral assailant's mass that will be blown off. The interaction is calculated for both kinetic-energy deflection and nuclear-explosive deflection. In the nuclear-explosive case, I calculate the interceptor mass and cratering effect for detonations above the surface and below the surface as well as directly on the surface of the astral assailant. Because the wide range of densities and material properties that the astral assailant may possess, the principal value of this work is to show the relationships among the salient parameters of the problem.

  2. Elliptic flow in heavy ion collisions near the balance energy

    E-Print Network [OSTI]

    Yu-Ming Zheng; C. M. Ko; Bao-An Li; Bin Zhang

    1999-06-24T23:59:59.000Z

    The proton elliptic flow in collisions of Ca on Ca at energies from 30 to 100 MeV/nucleon is studied in an isospin-dependent transport model. With increasing incident energy, the elliptic flow shows a transition from positive to negative flow. Its magnitude depends on both the nuclear equation of state (EOS) and the nucleon-nucleon scattering cross section. Different elliptic flows are obtained for a stiff EOS with free nucleon-nucleon cross sections and a soft EOS with reduced nucleon-nucleon cross sections, although both lead to vanishing in-plane transverse flow at the same balance energy. The study of both in-plane and elliptic flows at intermediate energies thus provides a means to extract simultaneously the information on the nuclear equation of state and the nucleon-nucleon scattering cross section in medium.

  3. Medium induced jet absorption at relativistic heavy ion collisions

    E-Print Network [OSTI]

    Axel Drees; Haidong Feng; Jiangyong Jia

    2005-05-31T23:59:59.000Z

    The dense medium created in Au + Au collisions at the Relativistic Heavy-Ion Collider (RHIC) significantly suppresses particle production from hard scattering processes and their characteristic back-to-back angular correlation. We present a simple model of jet absorption in dense matter which incorporates a realistic nuclear geometry. Our calculations are performed at the jet level and assume independent jet fragmentation in the vacuum. This model describes quantitatively the centrality dependence of the observed suppression of the high $p_T$ hadron yield and of the back-to-back angular correlations. The azimuthal anisotropy of high $p_T$ particle production can not be accounted for using a realistic nuclear geometry.

  4. Stellar mixing length theory with entropy rain

    E-Print Network [OSTI]

    Brandenburg, Axel

    2015-01-01T23:59:59.000Z

    Stellar mixing length theory is modified to include the effects of a nongradient term that originates from the motion of convective elements with entropy perturbations of either sign. It is argued that such a term, first studied by Deardorff in the meteorological context, represents the effects of thin intense downdrafts caused by the rapid cooling in the granulation layer at the top of the convection zone. They transport heat nonlocally, as originally anticipated by Spruit in the 1990s, who describes the convection in the strongly stratified simulations of Stein & Nordlund as entropy rain. Although our model has ill-determined free parameters, it demonstrates that solutions can be found that look similar to the original ones, except that the deeper layers are now Schwarzschild stable, so no giant cells are produced and the typical convective scale is that of granules even at larger depth. Consequences for modeling solar differential, the global dynamo, and sunspots are briefly discussed.

  5. Energy Loss in Nuclear Drell-Yan Process

    E-Print Network [OSTI]

    Jian-Jun Yang; Guang-Lie Li

    1998-05-21T23:59:59.000Z

    By means of the nuclear parton distributions which can be used to provide a good explanation for the EMC effect in the whole x range, we investigate the energy loss effect in nuclear Drell-Yan process. When the cross section of lepton pair production is considered varying with the center-of-mass energy of the nucleon-nucleon collision, we find that the nuclear Drell-Yan(DY) ratio is suppressed due to the energy loss, which balances the overestimate of the DY ratio only in consideration of the effect of nuclear parton distributions.

  6. Stress tensor and bulk viscosity in relativistic nuclear collisions 

    E-Print Network [OSTI]

    Fries, Rainer J.; Mueller, Berndt; Schaefer, Andreas.

    2008-01-01T23:59:59.000Z

    Station, Texas 77843, USA 2RIKEN/BNL Research Center, Brookhaven National Laboratory, Upton, New York 11973, USA 3Yukawa Institute of Theoretical Physics, Kyoto University, Kyoto 606-8502, Japan 4Department of Physics, Duke University, Durham, North... at the Relativistic Heavy Ion Collider (RHIC). The analysis of the data collected in these experiments [1?4] has shown that the matter flows very rapidly at the moment of its breakup into free-streaming hadrons. The collective flow also exhibits a large anisotropy...

  7. Decoherence and entropy production in relativistic nuclear collisions 

    E-Print Network [OSTI]

    Fries, Rainer J.; Mueller, Berndt; Schaefer, Andreas.

    2009-01-01T23:59:59.000Z

    /BNL Research Center, Brookhaven National Laboratory, Upton, New York 11973, USA Berndt Mu?ller Department of Physics, Duke University, Durham, North Carolina 27708, USA Andreas Scha?fer Institut fu?r Theoretische Physik, Universita?t Regensburg, D-93040... Collider (RHIC) in recent years to explore the formation and the properties of the quark gluon plasma (QGP). One striking discovery was the fact that ideal hydrodynamics could describe many salient features of the expansion and cooling of the fireball...

  8. Decoherence and entropy production in relativistic nuclear collisions

    E-Print Network [OSTI]

    Fries, Rainer J.; Mueller, Berndt; Schaefer, Andreas.

    2009-01-01T23:59:59.000Z

    ? ? k?)N ? 2e?? 2(k?02+k?2) . (15) To determine the normalization constant N we could calculate the energy density of gluons in the nucleus, ?g ? Eg V = 1 V T ? dt Tr [HD], but we will see later that our final result does not depend on N... ? ? 1 0 du u2 [e?au ? 2e?(a+b)u + e?(a+2b)u]. (32) After two partial integrations this can be brought into the form ?I2 = 2(2pi )5 #14; 2 ? 4 ( N2c ? 1 )2 N2c { ?[e?au ? 2e(a+b)u + e?(a+2b)u] ? ? 1 0 du ln u[a2e?au ? 2(a + b)2e...

  9. IN SEARCH OF HIGH DENSITY COLLECTIVE PHENOMENA IN NUCLEAR COLLISION

    E-Print Network [OSTI]

    Gyulassy, M.

    2010-01-01T23:59:59.000Z

    42, 1448 (1979). P. J. Siemens, J. 0. Rasmussen, Phys. Rev.Discussions with P. Siemens, J. Randrup, and W. D. Myersl . , and interpreted by P. Siemens as evidence for a blast

  10. PION, LIGHT FRAGMENT AND ENTROPY PRODUCTION IN NUCLEAR COLLISIONS

    E-Print Network [OSTI]

    Stocker, Horst

    2013-01-01T23:59:59.000Z

    Rev. C23 (1981) 1282. P. Siemens, J. Kapusta, Phys. Rev.I. Mishustin, I. Myhrer, P. Siemens, Phys. Lett. 958 (1980)private communications. P. Siemens, J. Rasmussen, Phys. Rev.

  11. Nuclear spectroscopic studies

    SciTech Connect (OSTI)

    Bingham, C.R.; Guidry, M.W.; Riedinger, L.L.; Sorensen, S.P.

    1993-02-08T23:59:59.000Z

    The Nuclear Physics group at the University of Tennessee, Knoxville is involved in several aspects of heavy-ion physics including both nuclear structure and reaction mechanisms. While our main emphasis is on experimental problems involving heavy-ion accelerators, we have maintained a strong collaboration with several theorists in order to best pursue the physics of our measurements. During the last year we have led several experiments at the Holifield Heavy Ion Research Facility and participated in others at Argonne National Laboratory. Also, we continue to be very active in the collaboration to study ultra-relativistic heavy ion physics utilizing the SPS accelerator at CERN in Geneva, Switzerland and in a RHIC detector R D project. Our experimental work is in four broad areas: (1) the structure of nuclei at high angular momentum, (2) heavy-ion induced transfer reactions, (3) the structure of nuclei far from stability, and (4) ultra-relativistic heavy-ion physics. The results of studies in these particular areas will be described in this document in sections IIA, IIB, IIC, and IID, respectively. Areas (1), (3), and (4) concentrate on the structure of nuclear matter in extreme conditions of rotational motion, imbalance of neutrons and protons, or very high temperature and density. Area (2) pursues the transfer of nucleons to states with high angular momentum, both to learn about their structure and to understand the transfer of particles, energy, and angular momentum in collisions between heavy ions. An important component of our program is the strong emphasis on the theoretical aspects of nuclear structure and reactions.

  12. Precision neutron interferometric measurement of the nd coherent neutron scattering length and consequences for models of three-nucleon forces

    E-Print Network [OSTI]

    T. C. Black; P. R. Huffman; D. L. Jacobson; W. M. Snow; K. Schoen; M. Arif; H. Kaiser; S. K. Lamoreaux; S. A. Werner

    2003-05-21T23:59:59.000Z

    We have performed the first high precision measurement of the coherent neutron scattering length of deuterium in a pure sample using neutron interferometry. We find b_nd = (6.665 +/- 0.004) fm in agreement with the world average of previous measurements using different techniques, b_nd = (6.6730 +/- 0.0045) fm. We compare the new world average for the nd coherent scattering length b_nd = (6.669 +/- 0.003) fm to calculations of the doublet and quartet scattering lengths from several modern nucleon-nucleon potential models with three-nucleon force (3NF) additions and show that almost all theories are in serious disagreement with experiment. This comparison is a more stringent test of the models than past comparisons with the less precisely-determined nuclear doublet scattering length of a_nd = (0.65 +/- 0.04) fm.

  13. Geometric Solutions for the Neutrino Oscillation Length Resonance

    E-Print Network [OSTI]

    Jason Pruet; George M. Fuller

    1999-04-02T23:59:59.000Z

    We give a geometric interpretation of the neutrino 'oscillation length resonance' recently discovered by Petcov. We use this picture to identify two new solutions for oscillation length resonances in a 3-layer earth model.

  14. Low-coherent WDM reflectometry for accurate fiber length monitoring

    E-Print Network [OSTI]

    Hui, Rongqing; Thomas, J.; Allen, Christopher Thomas; Fu, B.; Gao, S.

    2003-01-01T23:59:59.000Z

    A fiber-optic low-coherent reflectometer was developed to accurately monitor fiber length variation. A large length-coverage range was obtained by using a fiber Bragg grating array in a wavelength-division-multiplexing ...

  15. Dictionaries Using Variable-Length Keys and Data, with Applications *

    E-Print Network [OSTI]

    Blelloch, Guy E.

    (Isil- logn, 1) + Itil) and Isil is the length of bit string si. We assume a word length w > log m. We present string Isil > 1, Itil > 1 for all bit-strings si and ti. Fox' fixed-length keys the dictionary problem

  16. J/$?$ production in In-In and p-A collisions

    E-Print Network [OSTI]

    E. Scomparin

    2007-03-20T23:59:59.000Z

    The NA60 experiment studies dimuon production in In-In and p-A collisions at the CERN SPS. We report recent results on \\jpsi production, measured through its muon pair decay. As a function of centrality, we show that in In-In the \\jpsi yield is suppressed beyond expectations from nuclear absorption. We present also for the first time results on \\jpsi production in p-A collisions at 158 GeV, the same energy of the nucleus-nucleus data. For both p-A and In-In we show preliminary results on \\psip suppression. Finally, we have studied the kinematical distributions of the \\jpsi produced in In-In collisions. We present results on transverse momentum and rapidity, as well as on the angular distribution of the \\jpsi decay products.

  17. Study of jet fragmentation in p+p collisions at 200 GeV in the STAR experiment

    E-Print Network [OSTI]

    Elena Bruna; for the STAR Collaboration

    2009-02-12T23:59:59.000Z

    The measurement of jet fragmentation functions in p+p collisions at 200 GeV is of great interest because it provides a baseline to study jet quenching in heavy-ion collisions. It is expected that jet quenching in nuclear matter modifies the jet energy and multiplicity distributions, as well as the jet hadrochemical composition. Therefore, a systematic study of the fragmentation functions for charged hadrons and identified particles is a goal both in p+p and Au+Au collisions at RHIC. Studying fragmentation functions for identified particles is interesting in p+p by itself because it provides a test of NLO calculations at RHIC energies. We present a systematic comparison of jet energy spectra and fragment distributions using different jet-finding algorithms in p+p collisions in STAR. Fragmentation functions of charged and neutral strange particles are also reported for different jet energies.

  18. Centrality dependence of high $p_T$ suppression in Au+Au collisions suggest quark matter formation

    E-Print Network [OSTI]

    A. K. Chaudhuri

    2004-05-12T23:59:59.000Z

    In a pQCD-based model, we have analyzed the STAR data on the high $p_T$ suppression of charged hadrons, in Au+Au collisions at $\\sqrt{s}$=200 GeV. In the jet quenching or the energy loss picture, $p_T$ spectra of charged hadrons as well as the $p_T$ dependence of nuclear modification factor, in all the centrality ranges, are well explained, with nearly a constant relative energy loss, $\\Delta E/E=0.56\\pm 0.03$. Centrality independence of relative energy loss indicate that the matter produced in central and in peripheral collisions are different, otherwise relative energy loss would have shown strong centrality dependence. Qualitatively, centrality independence of relative energy loss can be understood, if in central Au+Au collisions deconfined matter is produced and the matter remain confined in peripheral collisions.

  19. Nuclear Structure and Dynamics from the Fully Unrestricted Skyrme-Hartree-Fock

    E-Print Network [OSTI]

    Stevenson, Paul

    and friendly environment in which to study nuclear physics. Special mention goes to my fellow theoristsNuclear Structure and Dynamics from the Fully Unrestricted Skyrme-Hartree-Fock Model A thesis performed for 16 O + 16 O and 28 Si + 16 O collisions at a variety of centre-of-mass energies and impact

  20. Fragile Signs of Criticality in the Nuclear Multifragmentation

    E-Print Network [OSTI]

    K. K. Gudima; M. Ploszajczak; V. D. Toneev

    2001-06-08T23:59:59.000Z

    Deviations from an idealized equilibrium phase transition picture in nuclear multifragmentation is studied in terms of the entropic index. We investigate different heat-capacity features in the canonical quantum statistical model of nuclear multifragmentation generalized in the framework of Tsallis nonextensive thermostatistics. We find that the negative branch of heat capacity observed in quasi-peripheral Au+Au collisions is caused primarily by the non-generic nonextensivity effects.

  1. Stopping effects in U+U collisions with a beam energy of 520 MeV/nucleon

    E-Print Network [OSTI]

    Xiao-Feng Luo; Xin Dong; Ming Shao; Ke-Jun Wu; Cheng Li; Hong-Fang Chen; Hu-Shan Xu

    2007-11-18T23:59:59.000Z

    A Relativistic Transport Model (ART1.0) is applied to simulate the stopping effects in tip-tip and body-body U+U collisions, at a beam kinetic energy of 520 MeV/nucleon. Our simulation results have demonstrated that both central collisions of the two extreme orientations can achieve full stopping, and also form a bulk of hot, dense nuclear matter with a sufficiently large volume and long duration, due to the largely deformed uranium nuclei. The nucleon sideward flow in the tip-tip collisions is nearly 3 times larger than that in body-body ones at normalized impact parameter $b/b_{max}EoS, respectively. The Cooling Storage Ring (CSR) External Target Facility (ETF) to be built at Lanzhou, China, delivering the uranium beam up to 520 MeV/nucleon is expected to make significant contribution to explore the nuclear equation of state (EoS).

  2. Centrality dependence of the charged-particle multiplicity density at mid-rapidity in Pb-Pb collisions at sqrt(sNN) = 2.76 TeV

    E-Print Network [OSTI]

    ALICE Collaboration; K. Aamodt; A. Abrahantes Quintana; D. Adamová; A. M. Adare; M. M. Aggarwal; G. Aglieri Rinella; A. G. Agocs; S. Aguilar Salazar; Z. Ahammed; N. Ahmad; A. Ahmad Masoodi; S. U. Ahn; A. Akindinov; D. Aleksandrov; B. Alessandro; R. Alfaro Molina; A. Alici; A. Alkin; E. Almaráz Avińa; T. Alt; V. Altini; S. Altinpinar; I. Altsybeev; C. Andrei; A. Andronic; V. Anguelov; C. Anson; T. Anti\\vci?; F. Antinori; P. Antonioli; L. Aphecetche; H. Appelshäuser; N. Arbor; S. Arcelli; A. Arend; N. Armesto; R. Arnaldi; T. Aronsson; I. C. Arsene; A. Asryan; A. Augustinus; R. Averbeck; T. C. Awes; J. Äystö; M. D. Azmi; M. Bach; A. Badalŕ; Y. W. Baek; S. Bagnasco; R. Bailhache; R. Bala; R. Baldini Ferroli; A. Baldisseri; A. Baldit; J. Bán; R. Barbera; F. Barile; G. G. Barnaföldi; L. S. Barnby; V. Barret; J. Bartke; M. Basile; N. Bastid; B. Bathen; G. Batigne; B. Batyunya; C. Baumann; I. G. Bearden; H. Beck; I. Belikov; F. Bellini; R. Bellwied; E. Belmont-Moreno; S. Beole; I. Berceanu; A. Bercuci; E. Berdermann; Y. Berdnikov; L. Betev; A. Bhasin; A. K. Bhati; L. Bianchi; N. Bianchi; C. Bianchin; J. Biel\\vc\\'\\ik; J. Biel\\vc\\'\\iková; A. Bilandzic; E. Biolcati; A. Blanc; F. Blanco; F. Blanco; D. Blau; C. Blume; M. Boccioli; N. Bock; A. Bogdanov; H. B\\oggild; M. Bogolyubsky; L. Boldizsár; M. Bombara; C. Bombonati; J. Book; H. Borel; C. Bortolin; S. Bose; F. Bossú; M. Botje; S. Böttger; B. Boyer; P. Braun-Munzinger; L. Bravina; M. Bregant; T. Breitner; M. Broz; R. Brun; E. Bruna; G. E. Bruno; D. Budnikov; H. Buesching; O. Busch; Z. Buthelezi; D. Caffarri; X. Cai; H. Caines; E. Calvo Villar; P. Camerini; V. Canoa Roman; G. Cara Romeo; F. Carena; W. Carena; F. Carminati; A. Casanova D\\'\\iaz; M. Caselle; J. Castillo Castellanos; V. Catanescu; C. Cavicchioli; P. Cerello; B. Chang; S. Chapeland; J. L. Charvet; S. Chattopadhyay; S. Chattopadhyay; M. Cherney; C. Cheshkov; B. Cheynis; E. Chiavassa; V. Chibante Barroso; D. D. Chinellato; P. Chochula; M. Chojnacki; P. Christakoglou; C. H. Christensen; P. Christiansen; T. Chujo; C. Cicalo; L. Cifarelli; F. Cindolo; J. Cleymans; F. Coccetti; J. -P. Coffin; S. Coli; G. Conesa Balbastre; Z. Conesa del Valle; P. Constantin; G. Contin; J. G. Contreras; T. M. Cormier; Y. Corrales Morales; I. Cortés Maldonado; P. Cortese; M. R. Cosentino; F. Costa; M. E. Cotallo; E. Crescio; P. Crochet; E. Cuautle; L. Cunqueiro; G. D Erasmo; A. Dainese; H. H. Dalsgaard; A. Danu; D. Das; I. Das; A. Dash; S. Dash; S. De; A. De Azevedo Moregula; G. O. V. de Barros; A. De Caro; G. de Cataldo; J. de Cuveland; A. De Falco; D. De Gruttola; N. De Marco; S. De Pasquale; R. De Remigis; R. de Rooij; H. Delagrange; Y. Delgado Mercado; G. Dellacasa; A. Deloff; V. Demanov; E. Dénes; A. Deppman; D. Di Bari; C. Di Giglio; S. Di Liberto; A. Di Mauro; P. Di Nezza; T. Dietel; R. Diviŕ; Ř. Djuvsland; A. Dobrin; T. Dobrowolski; I. Dom\\'\\inguez; B. Dönigus; O. Dordic; O. Driga; A. K. Dubey; L. Ducroux; P. Dupieux; A. K. Dutta Majumdar; M. R. Dutta Majumdar; D. Elia; D. Emschermann; H. Engel; H. A. Erdal; B. Espagnon; M. Estienne; S. Esumi; D. Evans; S. Evrard; G. Eyyubova; C. W. Fabjan; D. Fabris; J. Faivre; D. Falchieri; A. Fantoni; M. Fasel; R. Fearick; A. Fedunov; D. Fehlker; V. Fekete; D. Felea; G. Feofilov; A. Fernández Téllez; A. Ferretti; R. Ferretti; M. A. S. Figueredo; S. Filchagin; R. Fini; D. Finogeev; F. M. Fionda; E. M. Fiore; M. Floris; S. Foertsch; P. Foka; S. Fokin; E. Fragiacomo; M. Fragkiadakis; U. Frankenfeld; U. Fuchs; F. Furano; C. Furget; M. Fusco Girard; J. J. Gaardh\\oje; S. Gadrat; M. Gagliardi; A. Gago; M. Gallio; P. Ganoti; C. Garabatos; R. Gemme; J. Gerhard; M. Germain; C. Geuna; A. Gheata; M. Gheata; B. Ghidini; P. Ghosh; M. R. Girard; G. Giraudo; P. Giubellino; E. Gladysz-Dziadus; P. Glässel; R. Gomez; L. H. González-Trueba; P. González-Zamora; H. González Santos; S. Gorbunov; S. Gotovac; V. Grabski; R. Grajcarek; A. Grelli; A. Grigoras; C. Grigoras; V. Grigoriev; A. Grigoryan; S. Grigoryan; B. Grinyov; N. Grion; P. Gros; J. F. Grosse-Oetringhaus; J. -Y. Grossiord; R. Grosso; F. Guber; R. Guernane; C. Guerra Gutierrez; B. Guerzoni; K. Gulbrandsen; H. Gulkanyan; T. Gunji; A. Gupta; R. Gupta; H. Gutbrod; Ř. Haaland; C. Hadjidakis; M. Haiduc; H. Hamagaki; G. Hamar; J. W. Harris; M. Hartig; D. Hasch; D. Hasegan; D. Hatzifotiadou; A. Hayrapetyan; M. Heide; M. Heinz; H. Helstrup; A. Herghelegiu; C. Hernández; G. Herrera Corral; N. Herrmann; K. F. Hetland; B. Hicks; P. T. Hille; B. Hippolyte; T. Horaguchi; Y. Hori; P. Hristov; I. H\\vrivná\\vcová; M. Huang; S. Huber; T. J. Humanic; D. S. Hwang; R. Ichou; R. Ilkaev; I. Ilkiv; M. Inaba; E. Incani; G. M. Innocenti; P. G. Innocenti; M. Ippolitov; M. Irfan; C. Ivan; A. Ivanov; M. Ivanov; V. Ivanov; A. Jacho\\lkowski; P. M. Jacobs; L. Jancurová

    2011-02-04T23:59:59.000Z

    The centrality dependence of the charged-particle multiplicity density at mid-rapidity in Pb-Pb collisions at sqrt(sNN) = 2.76 TeV is presented. The charged-particle density normalized per participating nucleon pair increases by about a factor 2 from peripheral (70-80%) to central (0-5%) collisions. The centrality dependence is found to be similar to that observed at lower collision energies. The data are compared with models based on different mechanisms for particle production in nuclear collisions.

  3. Global versus Nuclear Starbursts

    E-Print Network [OSTI]

    Francoise Combes

    2001-06-24T23:59:59.000Z

    The strongest starbursts are observed towards galaxy nuclei, or circumnuclear regions. However in interacting galaxies, star formation is also triggered in overlap regions far from nuclei, in spiral arms and sometimes in tidal tails. What is the relative importance of these starbursts? What kind of starformation is dominating, as a function of redshift? These different starbursts occur in different dynamical conditions (global and local): gravitational instabilities, density waves, radial flows, shear, cloud collisions, density accumulations, and they have been investigated with the help of numerical simulations. Gravitational instabilities are necessary to initiate star formation, but they are not sufficient; galactic disks are self-regulated through these instabilities to have their Toomre Q parameter of the order of 1, and thus this criterium is in practice unable to predict the onset of intense star formation. Super star clusters are a characteristic SF mode in starbursts, and might be due to the rapid formation of large gas complexes. Star formation can propagate radially inwards, due to gravity torques and gas inflow, but also outwards, due to superwinds, and energy outflows: both expanding or collapsing waves are observed in circumnuclear regions. Mergers are more efficient in forming stars at high redshift, because of larger gas content, and shorter dynamical times. The relation between nuclear starbursts and nuclear activity is based on the same fueling mechanisms, but also on reciprocal triggering and regulations.

  4. 2013 Nuclear Workforce Development ...

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

    Nuclear Workforce Development Day Tuesday, October 22, 2013 Nuclear Medicine Topics: Pathways of Practice in Nuclear Medicine Radiopharmacy Patient Care ...

  5. Nuclear Counterterrorism

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2013-08-26T23:59:59.000Z

    The Order defines requirements for the protection of sensitive improvised nuclear device information and provides a framework to support DOE activities related to nuclear counterterrorism. (A supplemental DOE Manual, Control of and Access to Improvised Nuclear Device Information, provides requirements and procedures for protecting Sigma 20 information.) Appendices A and B are Official Use Only. Point of contact is Adam Boyd (NA-82), 202-586-0010. Cancels DOE O 457.1 and DOE M 457.1-1.

  6. Nuclear Power

    E-Print Network [OSTI]

    Vilhena and Bardo E.J. Bodmann Carbon-#1;? in Terrestrial and Aquatic Environment of Ignalina Nuclear Power Plant: Sources of Production, Releases and Dose Estimates #3;?? Jonas Mazeika Impact of radionuclide discharges from Temel?n Nuclear Power... (chapter 5), ? Instrumentation and control (chapter 6), ? Diagnostics (chapter 7), ? Safety evaluation methods (chapters 6, 8, 9 and 10), ? Environment and nuclear power plants (chapters 11 - 15), ? Human factors (chapter 16), ? Software development...

  7. Compact noninvasive electron bunch-length monitor

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

    Roberts, B.; Mammei, R. R.; Poelker, M.; McCarter, J. L.

    2012-12-01T23:59:59.000Z

    A compact rf cavity was constructed that simultaneously resonates at many harmonic modes when excited by a repetitive bunched electron beam passing through its bore. The excitation of these modes provides a Fourier description of the temporal characteristics of the bunch train. The cavity was used to noninvasively characterize electron bunches produced from thin and thick GaAs photocathodes inside a DC high voltage photogun illuminated with 37 ps (full width half maximum, FWHM) laser pulses at repetition rates near 1500 MHz, at average beam current from 5 to 500????A , and at beam energy from 75 to 195 keV. The cavity bunch-length monitor could detect electron bunches as short as 57 ps (FWHM) when connected directly to a sampling oscilloscope, and could clearly distinguish bunches with varying degrees of space-charge induced growth and with different tail signatures. Efforts are under way to detect shorter bunches by designing cavities with increased bandwidth. This demonstration lends credibility to the idea that these cavities could also be used for other applications, including bunching and shaping, when driven with external rf.

  8. Isospin dependent properties of asymmetric nuclear matter

    SciTech Connect (OSTI)

    Chowdhury, P. Roy [Saha Institute of Nuclear Physics, 1/AF Bidhan Nagar, Kolkata 700 064 (India); Basu, D. N. [Variable Energy Cyclotron Centre, 1/AF Bidhan Nagar, Kolkata 700 064 (India); Samanta, C. [Saha Institute of Nuclear Physics, 1/AF Bidhan Nagar, Kolkata 700 064 (India); Physics Department, Virginia Commonwealth University, Richmond, Virginia 232840 (United States); Physics Department, University of Richmond, Virginia 23173 (United States)

    2009-07-15T23:59:59.000Z

    The density dependence of nuclear symmetry energy is determined from a systematic study of the isospin dependent bulk properties of asymmetric nuclear matter using the isoscalar and isovector components of the density dependent M3Y interaction. The incompressibility K{sub {infinity}} for the symmetric nuclear matter, the isospin dependent part K{sub asy} of the isobaric incompressibility, and the slope L are all in excellent agreement with the constraints recently extracted from measured isotopic dependence of the giant monopole resonances in even-A Sn isotopes, from the neutron skin thickness of nuclei, and from analyses of experimental data on isospin diffusion and isotopic scaling in intermediate energy heavy-ion collisions. This work provides a fundamental basis for the understanding of nuclear matter under extreme conditions and validates the important empirical constraints obtained from recent experimental data.

  9. Isospin dependent properties of asymmetric nuclear matter

    E-Print Network [OSTI]

    P. Roy Chowdhury; D. N. Basu; C. Samanta

    2009-07-15T23:59:59.000Z

    The density dependence of nuclear symmetry energy is determined from a systematic study of the isospin dependent bulk properties of asymmetric nuclear matter using the isoscalar and the isovector components of density dependent M3Y interaction. The incompressibility $K_\\infty$ for the symmetric nuclear matter, the isospin dependent part $K_{asy}$ of the isobaric incompressibility and the slope $L$ are all in excellent agreement with the constraints recently extracted from measured isotopic dependence of the giant monopole resonances in even-A Sn isotopes, from the neutron skin thickness of nuclei and from analyses of experimental data on isospin diffusion and isotopic scaling in intermediate energy heavy-ion collisions. This work provides a fundamental basis for the understanding of nuclear matter under extreme conditions, and validates the important empirical constraints obtained from recent experimental data.

  10. Measurement of ?(1S+2S+3S) production in p+p and Au+Au collisions at ?sNN=200 GeV

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

    Adare, A. [Univ. of Colorado, Boulder, CO (United States)

    2015-02-01T23:59:59.000Z

    Measurements of bottomonium production in heavy ion and p+p collisions at the Relativistic Heavy Ion Collider (RHIC) are presented. The inclusive yield of the three ? states, ?(1S + 2S + 3S), was measured in the PHENIX experiment via electron-positron decay pairs at midrapidity for Au+Au and p+p collisions at ?sNN = 200 GeV. The ?(1S + 2S + 3S) ? e?e? differential cross section at midrapidity was found to be Beed?/dy = 108 ± 38 (stat) ± 15 (syst) ± 11 (luminosity) pb in p+p collisions. The nuclear modification factor in the 30% most central Au+Au collisions indicates a suppression of the total ? state yield relative to the extrapolation from p+p collision data. The suppression is consistent with measurements at higher energies by the CMS experiment at the Large Hadron Collider.

  11. Measurement of ?(1S+2S+3S) production in p+p and Au+Au collisions at ?sNN=200 GeV

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

    Adare, A.

    2015-02-01T23:59:59.000Z

    Measurements of bottomonium production in heavy ion and p+p collisions at the Relativistic Heavy Ion Collider (RHIC) are presented. The inclusive yield of the three ? states, ?(1S + 2S + 3S), was measured in the PHENIX experiment via electron-positron decay pairs at midrapidity for Au+Au and p+p collisions at ?sNN = 200 GeV. The ?(1S + 2S + 3S) ? e?e? differential cross section at midrapidity was found to be Beed?/dy = 108 ± 38 (stat) ± 15 (syst) ± 11 (luminosity) pb in p+p collisions. The nuclear modification factor in the 30% most central Au+Au collisions indicates amore »suppression of the total ? state yield relative to the extrapolation from p+p collision data. The suppression is consistent with measurements at higher energies by the CMS experiment at the Large Hadron Collider.« less

  12. NUCLEAR CHEMISTRY DIV. ANNUAL REPORT 1980-81

    E-Print Network [OSTI]

    Cerny, J.

    2010-01-01T23:59:59.000Z

    or estimated nuclear properties, and agreement with theagreement with much more complicated many-body calcu­ lations suggests that the low-density properties of nuclearnuclear collisions is studied in a simple bounce-off model. The calculated momentum transfers are in agreement

  13. Critical Temperature for the Nuclear Liquid-Gas Phase Transition

    E-Print Network [OSTI]

    V. A. Karnaukhov; H. Oeschler; S. P. Avdeyev; E. V. Duginova; V. K. Rodionov; A. Budzanowski; W. Karcz; O. V. Bochkarev; E. A. Kuzmin; L. V. Chulkov; E. Norbeck; A. S. Botvina

    2003-02-07T23:59:59.000Z

    The charge distribution of the intermediate mass fragments produced in p (8.1 GeV) + Au collisions is analyzed in the framework of the statistical multifragmentation model with the critical temperature for the nuclear liquid-gas phase transition $T_c$ as a free parameter. It is found that $T_c=20\\pm3$ MeV (90% CL).

  14. Nuclear Physics Laboratory annual report, University of Washington April 1992

    SciTech Connect (OSTI)

    Cramer, John G.; Ramirez, Maria G.

    1992-01-01T23:59:59.000Z

    This report contains short discusses on topics in the following areas: astrophysics; giant resonances and photonuclear reactions; nucleus-nucleus reactions; fundamental symmetries; accelerator mass spectrometry; medium energy nuclear physics; ultra-relativistic heavy ion collisions; cluster fusion; instrumentation; van de graaff accelerators and ion sources; and computer data acquisition systems. (LSP)

  15. Nuclear Physics Laboratory annual report, University of Washington April 1992

    SciTech Connect (OSTI)

    Not Available

    1992-07-01T23:59:59.000Z

    This report contains short discusses on topics in the following areas: astrophysics; giant resonances and photonuclear reactions; nucleus-nucleus reactions; fundamental symmetries; accelerator mass spectrometry; medium energy nuclear physics; ultra-relativistic heavy ion collisions; cluster fusion; instrumentation; van de graaff accelerators and ion sources; and computer data acquisition systems. (LSP)

  16. Measurement of heavy-flavor production in Pb-Pb collisions at the LHC with ALICE

    E-Print Network [OSTI]

    Robert Grajcarek; for the ALICE Collaboration

    2012-09-10T23:59:59.000Z

    A Large Ion Collider Experiment (ALICE) at the Large Hadron Collider (LHC) has been built in order to study the Quark-Gluon Plasma (QGP) created in high-energy nuclear collisions. As heavy-flavor quarks are produced at the early stage of the collision, they serve as sensitive probes for the QGP. The ALICE detector with its capabilities such as particle identification, secondary vertexing and tracking in a high multiplicity environment can address, among other measurements, the heavy-flavor sector in heavy-ion collisions. We present latest results on the measurement of the nuclear modification factor of open heavy-flavors as well as on the measurement of open heavy-flavor azimuthal anisotropy v2 in Pb-Pb collisions at sqrt(s) = 2.76 TeV. Open charmed hadrons are reconstructed in the hadronic decay channels D0->Kpi, D+->Kpipi, and D*+->D0pi applying a secondary decay-vertex topology. Complementary measurements are performed by detecting electrons (muons) from semi-leptonic decays of open heavy-flavor hadrons in the central (forward) rapidity region.

  17. Searching for Jets in Heavy Ion Collisions

    E-Print Network [OSTI]

    Salur, Sevil

    2008-01-01T23:59:59.000Z

    Proc. 24th Winter Workshop on Nuclear Dynamics (2008)000–000 24th Winter Workshop on Nuclear Dynamics South

  18. Measurement of beauty-hadron decay electrons in Pb--Pb collisions at sqrt(s_NN) = 2.76 TeV with ALICE

    E-Print Network [OSTI]

    Martin Völkl; for the ALICE Collaboration

    2014-12-08T23:59:59.000Z

    The ALICE Collaboration at the LHC studies heavy-ion collisions to investigate the properties of the Quark-Gluon Plasma (QGP). Heavy quarks (charm and beauty) are effective probes for this purpose. Both their energy loss in the medium as well as their possible thermalization yield information about the medium properties. Experimentally, the reconstruction of hadrons with charm valence quarks is possible. For hadrons with beauty valence quarks a promising strategy is the measurement of their decay electrons. To separate these from the background electrons (mainly from charm hadron decays, photon conversions or light-meson decays) the large decay length of beauty hadrons can be utilized. It leads to a relatively large typical impact parameter of the decay electrons. By comparing the impact parameter distribution of the signal electrons with those from the background sources, the signal can be statistically separated from the background. For this purpose a maximum likelihood fit is employed using impact parameter distribution templates from simulations. The resulting nuclear modification factor for electrons from beauty-hadron decays shows a sizeable suppression for p_T > 3 GeV, albeit still with large uncertainties.

  19. Evolution of event-by-event ET fluctuations over collision centrality in RHIC interactions

    SciTech Connect (OSTI)

    Armendariz, Raul [Department of Physics, New Mexico State University, Las Cruces, NM (United States)

    2006-07-11T23:59:59.000Z

    Preliminary results are presented for two analyses of transverse energy (ET) production measured with the electromagnetic calorimeters (EMC) of the Pioneering High Energy Nuclear Interaction Experiment (PHENIX), in relativistic nuclear interactions in Au+Au heavy-ion collisions created by the Relativistic Heavy Ion Collider (RHIC), at Brookhaven National Laboratory. Event-by-event ET distributions made across collision centrality were used in (1) measurements of 200 GeV , and (2) measurements of 200 GeV and 62.4 GeV ET distribution relative fluctuations {sigma}/ and {sigma}2/, where {sigma} is the standard deviation, and {sigma}2 the variance of each semi-inclusive distribution. Event centrality was selected in 5% wide bins and each bin represented by a modeled mean number of participant nucleons .

  20. Jets and dijets in Au+Au and p+p collisions at RHIC

    SciTech Connect (OSTI)

    Hardtke, D.; STAR Collaboration

    2002-12-09T23:59:59.000Z

    Recent data from RHIC suggest novel nuclear effects in the production of high p{sub T} hadrons. We present results from the STAR detector on high p{sub T} angular correlations in Au+Au and p+p collisions at {radical}S = 200 GeV/c. These two-particle angular correlation measurements verify the presence of a partonic hard scattering and fragmentation component at high p{sub T} in both central and peripheral Au+Au collisions. When triggering on a leading hadron with p{sub T}>4 GeV, we observe a quantitative agreement between the jet cone properties in p+p and all centralities of Au+Au collisions. This quantitative agreement indicates that nearly all hadrons with p{sub T}>4 GeV/c come from jet fragmentation and that jet fragmentation properties are not substantially modified in Au+Au collisions. STAR has also measured the strength of back-to-back high p{sub T} charged hadron correlations, and observes a small suppression of the back-to-back correlation strength in peripheral collisions, and a nearly complete disappearance o f back-to-back correlations in central Au+Au events. These phenomena, together with the observed strong suppression of inclusive yields and large value of elliptic flow at high p{sub T}, are consistent with a model where high p{sub T} hadrons come from partons created near the surface of the collision region, and where partons that originate or propagate towards the center of the collision region are substantially slowed or completely absorbed.

  1. $J/?$ suppression and $p_T$ spectra in RHIC and LHC energy collisions

    E-Print Network [OSTI]

    A. K. Chaudhuri

    2008-11-24T23:59:59.000Z

    In a hydrodynamic model, we have studied $J/\\psi$ production in Au+Au/Cu+Cu collisions at RHIC energy $\\sqrt{s}$=200 GeV. At the initial time, $J/\\psi$'s are randomly distributed in the fluid. As the fluid evolve in time, the free streaming $J/\\psi$'s are dissolved if the local fluid temperature exceeds a threshold temperature $T_{J/\\psi}$. Sequential melting of charmonium states ($\\chi_c$, $\\psi\\prime$ and $J/\\psi$), with melting temperatures $T_{\\chi_c}=T_{\\psi\\prime} \\approx 1.2T_c$, $T_{J/\\psi} \\approx2T_c$ and feed-down fraction $F\\approx 0.3$, explains the PHENIX data on the centrality dependence of $J/\\psi$ suppression in Au+Au collisions. $J/\\psi$ $p_T$ spectra and the nuclear modification factor in Au+Au collisions are also well explained in the model. The model however over predict centrality dependence of $J/\\psi$ suppression in Cu+Cu collisions by 20-30%. The $J/\\psi$ $p_T$ spectra are under predicted by 20-30%. The model predict that in central Pb+Pb collisions at LHC energy, $\\sqrt{s}$=5500 GeV, $J/\\psi$'s are suppressed by a factor of $\\sim$ 10. The model predicted $J/\\psi$ $p_T$ distribution in Pb+Pb collisions at LHC is similar to that in Au+Au collisions at RHIC.

  2. $J/?$ production in Au+Au/Cu+Cu collisions at $\\sqrt{s}_{NN}$=200 GeV and the threshold model

    E-Print Network [OSTI]

    A. K. Chaudhuri

    2006-10-09T23:59:59.000Z

    Using the QGP motivated threshold model, where all the $J/\\psi$'s are suppressed above a threshold density, we have analyzed the preliminary PHENIX data on the centrality dependence of nuclear modification factor for $J/\\psi$'s in Cu+Cu and in Au+Au collisions, at RHIC energy, $\\sqrt{s}_{NN}$=200 GeV. Centrality dependence of $J/\\psi$ suppression in Au+Au collisions are well explained in the model for threshold densities in ranges of 3.6-3.7 $fm^{-2}$. $J/\\psi$ suppression in Cu+Cu collisions on the other hand are not explained in the model.

  3. Full jet reconstruction in 200 GeV p+p, d+Au and Au+Au collisions by STAR

    E-Print Network [OSTI]

    Jan Kapitan; for the STAR Collaboration

    2009-09-16T23:59:59.000Z

    Measurements of inclusive hadron suppression and di-hadron azimuthal correlations have provided important insights into jet quenching in hot QCD matter. However, they do not provide access to the energy of the hard scattering and are limited in their sensitivity since they can be affected by biases toward hard fragmentation and small energy loss. Full jet reconstruction in heavy-ion collisions enables a complete study of the modification of jet structure due to energy loss, but is challenging due to the high multiplicity environment. Study of jet production and properties in d+Au and p+p collisions provides important baseline measurement for jet studies in heavy-ion collisions. We report measurements of fully reconstructed jets in p+p, d+Au and Au+Au collisions at $\\sqrt{s_\\mathrm{NN}} = 200 \\mathrm{GeV}$ from the STAR experiment at RHIC. Measurement of initial state nuclear effects in d+Au collisions utilizing di-jet azimuthal correlations is presented together with similar measurement in p+p collisions. Inclusive jet $\\pt$ spectra and fragmentation functions in p+p and central Au+Au collisions are reported, with subsequent studies of jet nuclear modification factor, jet energy profile and modifications in the fragmentation function due to jet quenching.

  4. On the accuracy of using Fokker Planck equation in heavy ion collision

    E-Print Network [OSTI]

    Dutta, Nirupam

    2015-01-01T23:59:59.000Z

    Application of Fokker-Planck equation to heavy quark transport in the evolving medium created in heavy ion collision is critically scrutinised. We realise that the approach introduces a moderate uncertainty in drag and diffusion coefficients culminating in huge ambiguity in the theoretical prediction of nuclear modification factor $R_{AA}$. Quantitative estimation of the error is presented by considering recent developments in this field.

  5. Chemistry-nuclear chemistry division. Progress report, October 1979-September 1980

    SciTech Connect (OSTI)

    Ryan, R.R. (comp.)

    1981-05-01T23:59:59.000Z

    This report presents the research and development programs pursued by the Chemistry-Nuclear Chemistry Division of the Los Alamos National Laboratory. Topics covered include advanced analytical methods, atmospheric chemistry and transport, biochemistry, biomedical research, element migration and fixation, inorganic chemistry, isotope separation and analysis, atomic and molecular collisions, molecular spectroscopy, muonic x rays, nuclear cosmochemistry, nuclear structure and reactions, radiochemical separations, theoretical chemistry, and unclassified weapons research.

  6. National Nuclear Security Administration | National Nuclear Security...

    National Nuclear Security Administration (NNSA)

    National Nuclear Security Administration | National Nuclear Security Administration Facebook Twitter Youtube Flickr RSS People Mission Managing the Stockpile Preventing...

  7. Nuclear war, nuclear proliferation, and their consequences

    SciTech Connect (OSTI)

    Aga Khan, S.

    1986-01-01T23:59:59.000Z

    This book presents papers on nuclear weapons proliferation. Topics considered include the Nuclear Non-Proliferation Treaty and its future, the spread of nuclear weapons among nations, the link between horizontal and vertical proliferation, national security, nuclear disarmament, the impact of nuclear weapons on Third World regional conflicts, the global effects of a nuclear war, medical effects on human populations, the nuclear winter, the nuclear arms race, and arms control.

  8. NUCLEAR PLANT OPERATIONS AND

    E-Print Network [OSTI]

    Pázsit, Imre

    NUCLEAR PLANT OPERATIONS AND CONTROL KEYWORDS: neutron flux, cur- rent noise, vibration diagnostics: Swedish Nuclear Powe

  9. Nuclear Energy Density Functionals: What do we really know?

    E-Print Network [OSTI]

    Bulgac, Aurel; Jin, Shi

    2015-01-01T23:59:59.000Z

    We present the simplest nuclear energy density functional (NEDF) to date, determined by only 4 significant phenomenological parameters, yet capable of fitting measured nuclear masses with better accuracy than the Bethe-Weizs\\"acker mass formula, while also describing density structures (charge radii, neutron skins etc.) and time-dependent phenomena (induced fission, giant resonances, low energy nuclear collisions, etc.). The 4 significant parameters are necessary to describe bulk nuclear properties (binding energies and charge radii); an additional 2 to 3 parameters have little influence on the bulk nuclear properties, but allow independent control of the density dependence of the symmetry energy and isovector excitations, in particular the Thomas-Reiche-Kuhn sum rule. This Hohenberg-Kohn-style of density functional theory successfully realizes Weizs\\"acker's ideas and provides a computationally tractable model for a variety of static nuclear properties and dynamics, from finite nuclei to neutron stars, where...

  10. Nuclear Counterterrorism

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2006-02-07T23:59:59.000Z

    The Order defines requirements for the protection of sensitive improvised nuclear device information and provides a framework to support DOE activities related to nuclear counterterrorism. (A supplemental DOE Manual, Control of and Access to Improvised Nuclear Device Information, provides requirements and procedures for protecting Sigma 20 information. The Manual is Official Use Only, and is not available on the Directives Portal. The point of contact for the Manual is Randall Weidman, NA-121.2, 202-586-4582.) Canceled by DOE O 457.1A

  11. Structuring Materials on Multiple Length Scales for Energy Application...

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

    Structuring Materials on Multiple Length Scales for Energy Applications October 25, 2012 at 3pm36-428 Adreas Stein Department of Chemistry, University of Minnesota astein...

  12. Ultra-low-loss tapered optical fibers with minimal lengths

    E-Print Network [OSTI]

    Ryutaro Nagai; Takao Aoki

    2014-11-09T23:59:59.000Z

    We design and fabricate ultra-low-loss tapered optical fibers (TOFs) with minimal lengths. We first optimize variations of the torch scan length using the flame-brush method for fabricating TOFs with taper angles that satisfy the adiabaticity criteria. We accordingly fabricate TOFs with optimal shapes and compare their transmission to TOFs with a constant taper angle and TOFs with an exponential shape. The highest transmission measured for TOFs with an optimal shape is in excess of 99.7 % with a total TOF length of only 23 mm, whereas TOFs with a constant taper angle of 2 mrad reach 99.6 % transmission for a 63 mm TOF length.

  13. Energy transport through rare collisions

    E-Print Network [OSTI]

    François Huveneers

    2011-07-14T23:59:59.000Z

    We study a one-dimensional hamiltonian chain of masses perturbed by an energy conserving noise. The dynamics is such that, according to its hamiltonian part, particles move freely in cells and interact with their neighbors through collisions, made possible by a small overlap of size $\\epsilon > 0$ between near cells. The noise only randomly flips the velocity of the particles. If $\\epsilon \\rightarrow 0$, and if time is rescaled by a factor $1/{\\epsilon}$, we show that energy evolves autonomously according to a stochastic equation, which hydrodynamic limit is known in some cases. In particular, if only two different energies are present, the limiting process coincides with the simple symmetric exclusion process.

  14. Energy flow observables in hadronic collisions

    E-Print Network [OSTI]

    F. Hautmann

    2012-05-24T23:59:59.000Z

    We present recent QCD calculations of energy flow distributions associated with the production of jets at wide rapidity separations in high-energy hadron collisions, and discuss the role of these observables to analyze contributions from parton showering and from multiple parton collisions.

  15. Iron Air collision with high density QCD

    E-Print Network [OSTI]

    Hans-Joachim Drescher

    2006-12-08T23:59:59.000Z

    The color glass condensate approach describes successfully heavy ion collisions at RHIC. We investigate Iron-air collisions within this approach and compare results to event generators commonly used in air shower simulations. We estimate uncertainties in the extrapolation to GZK energies and discuss implications for air shower simulations.

  16. Chemistry-Nuclear Chemistry Division. Progress report, October 1980-September 1981

    SciTech Connect (OSTI)

    Ryan, R.R. (comp.)

    1982-05-01T23:59:59.000Z

    This report describes major progress in the research and development programs pursued by the Chemistry-Nuclear Chemistry Division of the Los Alamos National Laboratory during FY 1981. Topics covered include advanced analytical methods, atmospheric chemistry and transport, biochemistry, biomedical research, medical radioisotopes research, element migration and fixation, nuclear waste isolation research, inorganic and structural chemistry, isotope separation, analysis and applications, the newly established Nuclear Magnetic Resonance Center, atomic and molecular collisions, molecular spectroscopy, nuclear cosmochemistry, nuclear structure and reactions, pion charge exchange, radiochemical separations, theoretical chemistry, and unclassified weapons research.

  17. Nuclear Celebrations

    E-Print Network [OSTI]

    Hacker, Randi; Tsutsui, William

    2006-11-01T23:59:59.000Z

    Broadcast Transcript: The North Korean situation is frightening for many reasons but none, perhaps, more eerily disturbing than images of North Koreans celebrating in brightly colored costumes just days after the nation's underground nuclear test...

  18. Suppression of Y production in d + Au + and Au + Au collisions at ?sNN =200 GeV

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

    none,

    2014-07-01T23:59:59.000Z

    We report measurements of Upsilon meson production in p + p, d +Au, and Au+Aucollisions using the STAR detector at RHIC. We compare the Upsilon yield to the measured cross section in p + p collisions in order to quantify any modifications of the yield in cold nuclear matter using d +Au data and in hot nuclear matter using Au+Au data separated into three centrality classes. Our p +p measurement is based on three times the statistics of our previous result. We obtain a nuclear modification factor for Upsilon (1S + 2S + 3S) in the rapidity range |y| more »1 in d + Au collisions of RdAu = 0.79 ± 0.24(stat.) ± 0.03(syst.) ± 0.10(p + p syst.). A comparison with models including shadowing and initial state part on energy loss indicates the presence of additional cold-nuclear matter suppression. Similarly, in the top 10% most-central Au + Au collisions, we measure a nuclear modification factor of R AA = 0.49 ±0.1(stat.) ±0.02(syst.) ±0.06(p + p syst.), which is a larger suppression factor than that seen in cold nuclear matter. Our results are consistent with complete suppression of excited-state Upsilon mesons in Au + Au collisions. The additional suppression in Au + Au is consistent with the level expected in model calculations that include the presence of a hot, deconfined Quark–Gluon Plasma. However, understanding the suppression seen in d + Au is still needed before any definitive statements about the nature of the suppression in Au + Au can be made.« less

  19. Suppression of upsilon Production in d + Au and Au + Au collisions at root s=200 GeV

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

    Adamczyk, L.; STAR Collaboration

    2014-07-01T23:59:59.000Z

    We report measurements of Upsilon meson production in p + p, d +Au, and Au+Aucollisions using the STAR detector at RHIC. We compare the Upsilon yield to the measured cross section in p + p collisions in order to quantify any modifications of the yield in cold nuclear matter using d +Au data and in hot nuclear matter using Au+Au data separated into three centrality classes. Our p +p measurement is based on three times the statistics of our previous result. We obtain a nuclear modification factor for Upsilon (1S + 2S + 3S) in the rapidity range |y| more »1 in d + Au collisions of RdAu = 0.79 ± 0.24(stat.) ± 0.03(syst.) ± 0.10(p + p syst.). A comparison with models including shadowing and initial state part on energy loss indicates the presence of additional cold-nuclear matter suppression. Similarly, in the top 10% most-central Au + Au collisions, we measure a nuclear modification factor of R AA = 0.49 ±0.1(stat.) ±0.02(syst.) ±0.06(p + p syst.), which is a larger suppression factor than that seen in cold nuclear matter. Our results are consistent with complete suppression of excited-state Upsilon mesons in Au + Au collisions. The additional suppression in Au + Au is consistent with the level expected in model calculations that include the presence of a hot, deconfined Quark–Gluon Plasma. However, understanding the suppression seen in d + Au is still needed before any definitive statements about the nature of the suppression in Au + Au can be made.« less

  20. Nuclear Nonproliferation

    SciTech Connect (OSTI)

    Atkins-Duffin, C E

    2008-12-10T23:59:59.000Z

    With an explosion equivalent of about 20kT of TNT, the Trinity test was the first demonstration of a nuclear weapon. Conducted on July 16, 1945 in Alamogordo, NM this site is now a Registered National Historic Landmark. The concept and applicability of nuclear power was demonstrated on December 20, 1951 with the Experimental Breeder Reactor Number One (EBR-1) lit four light bulbs. This reactor is now a Registered National Historic Landmark, located near Arco, ID. From that moment forward it had been clearly demonstrated that nuclear energy has both peaceful and military applications and that the civilian and military fuel cycles can overlap. For the more than fifty years since the Atoms for Peace program, a key objective of nuclear policy has been to enable the wider peaceful use of nuclear energy while preventing the spread of nuclear weapons. Volumes have been written on the impact of these two actions on the world by advocates and critics; pundits and practioners; politicians and technologists. The nations of the world have woven together a delicate balance of treaties, agreements, frameworks and handshakes that are representative of the timeframe in which they were constructed and how they have evolved in time. Collectively these vehicles attempt to keep political will, nuclear materials and technology in check. This paper captures only the briefest abstract of the more significant aspects on the Nonproliferation Regime. Of particular relevance to this discussion is the special nonproliferation sensitivity associated with the uranium isotope separation and spent fuel reprocessing aspects of the nuclear fuel cycle.

  1. Nuclear reactor safety device

    DOE Patents [OSTI]

    Hutter, Ernest (Wilmette, IL)

    1986-01-01T23:59:59.000Z

    A safety device is disclosed for use in a nuclear reactor for axially repositioning a control rod with respect to the reactor core in the event of an upward thermal excursion. Such safety device comprises a laminated helical ribbon configured as a tube-like helical coil having contiguous helical turns with slidably abutting edges. The helical coil is disclosed as a portion of a drive member connected axially to the control rod. The laminated ribbon is formed of outer and inner laminae. The material of the outer lamina has a greater thermal coefficient of expansion than the material of the inner lamina. In the event of an upward thermal excursion, the laminated helical coil curls inwardly to a smaller diameter. Such inward curling causes the total length of the helical coil to increase by a substantial increment, so that the control rod is axially repositioned by a corresponding amount to reduce the power output of the reactor.

  2. Centrality dependence of strangeness production in heavy-ion collisions as a geometrical effect of core-corona superposition

    E-Print Network [OSTI]

    F. Becattini; J. Manninen

    2008-11-23T23:59:59.000Z

    It is shown that data on strange particle production as a function of centrality in Au-Au collisions at \\sqrt(s)_{NN}= 200 GeV can be explained with a superposition of emission from a hadron gas at full chemical equilibrium (core) and from nucleon-nucleon collisions at the boundary (corona) of the overlapping region of the two colliding nuclei. This model nicely accounts for the enhancement of phi meson and strange particle production as a function of centrality observed in relativistic heavy ion collisions at that energy. The enhancement is mainly a geometrical effect, that is the increasing weight of the core with respect to corona for higher centrality, while strangeness canonical suppression in the core seems to play a role only in very peripheral collisions. This model, if confirmed at lower energy, would settle the long-standing problem of strangeness under-saturation in relativistic heavy ion collisions, parametrized by $\\gs$. Furthermore, it would give a unique tool to locate the onset of deconfinement in nuclear collisions both as a function of energy and centrality if this is to be associated to the onset of the formation of a fully equilibrated core.

  3. Sighting optics including an optical element having a first focal length and a second focal length and methods for sighting

    DOE Patents [OSTI]

    Crandall, David Lynn

    2011-08-16T23:59:59.000Z

    Sighting optics include a front sight and a rear sight positioned in a spaced-apart relation. The rear sight includes an optical element having a first focal length and a second focal length. The first focal length is selected so that it is about equal to a distance separating the optical element and the front sight and the second focal length is selected so that it is about equal to a target distance. The optical element thus brings into simultaneous focus for a user images of the front sight and the target.

  4. Nuclear Science/Nuclear Chemistry

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOnItemResearch > TheNuclear Astrophysics One of the greatNuclear Science/Nuclear

  5. Measurement of K0S and K*0 in p+p, d+Au, and Cu+Cu collisions at sqrt SNN = 200 GeV

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

    Adare, A.; Aidala, C.

    2014-11-01T23:59:59.000Z

    The PHENIX experiment at the Relativistic Heavy Ion Collider has performed a systematic study of K0S and K*0 meson production at midrapidity in p+p, d+Au, and Cu+Cu collisions at sqrt SNN = 200 GeV. The K0S and K*0 mesons are reconstructed via their K0S and ?0(???)?0 (???) and K*0 ? K ±#25;?± decay modes, respectively. The measured transverse-momentum spectra are used to determine the nuclear modification factor of K0S and K*0 mesons in d+Au and Cu+Cu collisions at different centralities. In the d+Au collisions, the nuclear modification factor of K0S and K*0 mesons is almost constant as a function ofmore »transverse momentum and is consistent with unity showing that cold-nuclear-matter effects do not play a significant role in the measured kinematic range. In Cu+Cu collisions, within the uncertainties no nuclear modification is registered in peripheral collisions. In central collisions, both mesons show suppression relative to the expectations from the p+p yield scaled by the number of binary nucleon-nucleon collisions in the Cu+Cu system. In the pT range 2–5 GeV/c, the strange mesons ( K0S, K*0) similarly to the #30;? meson with hidden strangeness, show an intermediate suppression between the more suppressed light quark mesons (?0) and the nonsuppressed baryons (p, p-bar). At higher transverse momentum, pT > 5 GeV/c, production of all particles is similarly suppressed by a factor of ?2. (auth)« less

  6. Measurement of K0S and K*0 in p+p, d+Au, and Cu+Cu collisions at sqrt SNN = 200 GeV

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

    Adare, A. [Univ. of Colorado, Boulder, CO (United States); Aidala, C. [Columbia Univ., New York, NY (United States). et al.

    2014-11-01T23:59:59.000Z

    The PHENIX experiment at the Relativistic Heavy Ion Collider has performed a systematic study of K0S and K*0 meson production at midrapidity in p+p, d+Au, and Cu+Cu collisions at sqrt SNN = 200 GeV. The K0S and K*0 mesons are reconstructed via their K0S and ?0(???)?0 (???) and K*0 ? K ±#25;?± decay modes, respectively. The measured transverse-momentum spectra are used to determine the nuclear modification factor of K0S and K*0 mesons in d+Au and Cu+Cu collisions at different centralities. In the d+Au collisions, the nuclear modification factor of K0S and K*0 mesons is almost constant as a function of transverse momentum and is consistent with unity showing that cold-nuclear-matter effects do not play a significant role in the measured kinematic range. In Cu+Cu collisions, within the uncertainties no nuclear modification is registered in peripheral collisions. In central collisions, both mesons show suppression relative to the expectations from the p+p yield scaled by the number of binary nucleon-nucleon collisions in the Cu+Cu system. In the pT range 2–5 GeV/c, the strange mesons ( K0S, K*0) similarly to the #30;? meson with hidden strangeness, show an intermediate suppression between the more suppressed light quark mesons (?0) and the nonsuppressed baryons (p, p-bar). At higher transverse momentum, pT > 5 GeV/c, production of all particles is similarly suppressed by a factor of ?2. (auth)

  7. Simulating Collisions for Hydrokinetic Turbines

    SciTech Connect (OSTI)

    Richmond, Marshall C.; Romero Gomez, Pedro DJ; Rakowski, Cynthia L.

    2013-10-01T23:59:59.000Z

    Evaluations of blade-strike on an axial-flow Marine Hydrokinetic turbine were conducted using a conventional methodology as well as an alternative modeling approach proposed in the present document. The proposed methodology integrates the following components into a Computa- tional Fluid Dynamics (CFD) model: (i) advanced eddy-resolving flow simulations, (ii) ambient turbulence based on field data, (iii) moving turbine blades in highly transient flows, and (iv) Lagrangian particles to mimic the potential fish pathways. The sensitivity of blade-strike prob- ability to the following conditions was also evaluated: (i) to the turbulent environment, (ii) to fish size and (iii) to mean stream flow velocity. The proposed methodology provided fraction of collisions and offered the capability of analyzing the causal relationships between the flow envi- ronment and resulting strikes on rotating blades. Overall, the conventional methodology largely overestimates the probability of strike, and lacks the ability to produce potential fish and aquatic biota trajectories as they interact with the rotating turbine. By using a set of experimental corre- lations of exposure-response of living fish colliding on moving blades, the occurrence, frequency and intensity of the particle collisions was next used to calculate the survival rate of fish crossing the MHK turbine. This step indicated survival rates always greater than 98%. Although the proposed CFD framework is computationally more expensive, it provides the advantage of evaluating multiple mechanisms of stress and injury of hydrokinetic turbine devices on fish.

  8. Observation of structure in laser-induced Penning and associative ionization in crossed-beam Na+Na collisions

    SciTech Connect (OSTI)

    Polak-Dingels, P.; Delpech, J.; Weiner, J.

    1980-06-23T23:59:59.000Z

    The results of double-laser experiments in which Na/sup +//sub 2/ and Na/sup +/ are produced in crossed-alkali beams under single-collision conditions in the presence of strong optical fields are reported. Structure in the mass-selected product ion intensity as a function laser frequency is observed when the optical field is strongly focused and tuned far off atomic or dimer transitions. These measurements are the first to show that nuclear motion of the quasimolecular collision intermediate plays an important role in laser-induced collisional ionization.

  9. A Study of Query Length Avi Arampatzis1

    E-Print Network [OSTI]

    Arampatzis, Avi

    length, and fit power-law and Poisson distribu- tions to four different query sets. We provide and a power-law distribution for longer queries, that better fits real query length distributions than earlier proposals. Categories and Subject Descriptors: H.3 [Information Storage and Re- trieval]: H.3.3 Information

  10. On Termination and Derivation Lengths for Ground Rewrite Systems

    E-Print Network [OSTI]

    Giesl, Juergen

    On Termination and Derivation Lengths for Ground Rewrite Systems Dieter Hofbauer 1 Universit¨at GH@theory.informatik.uni­kassel.de Abstract. It is shown that for terminating ground term rewrite systems the length of derivations a suitable interpretation into the natural numbers. Terminating ground systems are not necessarily

  11. Scaling Behavior and Equilibrium Lengths of Knotted Polymers

    E-Print Network [OSTI]

    Bigelow, Stephen

    Scaling Behavior and Equilibrium Lengths of Knotted Polymers Eric Rawdon Akos Dobay John C. Kern numerical simulations to investigate how the chain length and topology of freely fluctuating knotted polymer of a characteristic changes with the chain size and how this change depends on the topology of the modeled polymers

  12. Macroscopic/microscopic simulation of nuclear reactions at intermediate energies. Denis Lacroix, Aymeric Van Lauwe and Dominique Durand

    E-Print Network [OSTI]

    Boyer, Edmond

    Macroscopic/microscopic simulation of nuclear reactions at intermediate energies. Denis Lacroix- tion of nuclear collisions in the intermediate energy range is presented. The model simulates events for reactions close to the fusion barrier (5-10 MeV/A) up to higher energy (100 MeV/A) and it gives access

  13. Nuclear Science Division annual report, July 1, 1981-September 30, 1982

    SciTech Connect (OSTI)

    Mahoney, J. (ed.)

    1983-06-01T23:59:59.000Z

    This report summarizes the scientific research carried out within the Nuclear Science Division between July 1, 1981, and September 30, 1982. Heavy-ion investigations continue to dominate the experimental and theoretical research efforts. Complementary programs in light-ion nuclear science, in nuclear data evaluation, and in the development of advanced instrumentation are also carried out. Results from Bevalac experiments employing a wide variety of heavy ion beams, along with new or upgraded detector facilities (HISS, the Plastic Ball, and the streamer chamber) are contained in this report. These relativistic experiments have shed important light on the degree of equilibration for central collisions, the time evolution of a nuclear collision, the nuclear density and compressional energy of these collisions, and strange particle production. Reaction mechanism work dominates the heavy-ion research at the 88-Inch Cyclotron and the SuperHILAC. Recent experiments have contributed to our understanding of the nature of light-particle emission in deep-inelastic collisions, of peripheral reactions, incomplete fusion, fission, and evaporation. Nuclear structure investigations at these accelerators continue to be directed toward the understanding of the behavior of nuclei at high angular momentum. Research in the area of exotic nuclei has led to the observation at the 88-Inch Cyclotron of the ..beta..-delayed proton decay of odd-odd T/sub z/ = -2 nuclides; ..beta..-delayed proton emitters in the rare earth region are being investigated at the SuperHILAC.

  14. Nuclear Proliferation Technology Trends Analysis

    SciTech Connect (OSTI)

    Zentner, Michael D.; Coles, Garill A.; Talbert, Robert J.

    2005-10-04T23:59:59.000Z

    A process is underway to develop mature, integrated methodologies to address nonproliferation issues. A variety of methodologies (both qualitative and quantitative) are being considered. All have one thing in common, a need for a consistent set of proliferation related data that can be used as a basis for application. One approach to providing a basis for predicting and evaluating future proliferation events is to understand past proliferation events, that is, the different paths that have actually been taken to acquire or attempt to acquire special nuclear material. In order to provide this information, this report describing previous material acquisition activities (obtained from open source material) has been prepared. This report describes how, based on an evaluation of historical trends in nuclear technology development, conclusions can be reached concerning: (1) The length of time it takes to acquire a technology; (2) The length of time it takes for production of special nuclear material to begin; and (3) The type of approaches taken for acquiring the technology. In addition to examining time constants, the report is intended to provide information that could be used to support the use of the different non-proliferation analysis methodologies. Accordingly, each section includes: (1) Technology description; (2) Technology origin; (3) Basic theory; (4) Important components/materials; (5) Technology development; (6) Technological difficulties involved in use; (7) Changes/improvements in technology; (8) Countries that have used/attempted to use the technology; (9) Technology Information; (10) Acquisition approaches; (11) Time constants for technology development; and (12) Required Concurrent Technologies.

  15. EMC effect and jet energy loss in relativistic deuteron-nucleus collisions

    E-Print Network [OSTI]

    B. A. Cole; G. G. Barnafoldi; P. Levai; G. Papp; G. Fai

    2007-02-09T23:59:59.000Z

    We investigate the influence of modified nuclear parton distribution functions (PDFs) on high-pT hadron production at RHIC and LHC energies using a pQCD-improved parton model. For application at RHIC, we focus on the possible contribution of the EMC modification of the nuclear PDFs in the x > 0.3 region to the observed suppression of pi0 production at pT > 10 GeV/c in dAu collisions. We study three different parameterizations of the nuclear PDF modifications and find that they give consistent results for R_dAu(pT) for neutral pions in the region 10 GeV/c EMC suppression of the parton distributions in the Au nucleus does not strongly influence the R_dAu for pi0 in the pT region where the suppression is observed. Using the HKN parameterization, we evaluate systematic errors in the theoretical R_dAu(pT) resulting from uncertainties in the nuclear PDFs. The measured nuclear modification factor is inconsistent with the pQCD model result for pT > 10 GeV/c even when the systematic uncertainties in the nuclear PDFs are accounted for. The inclusion of a small final-state energy loss can reduce the discrepancy with the data, but we cannot perfectly reproduce the pT dependence of the measured R_dAu(pT). For the LHC, we find that shadowing of the nuclear PDFs produces a large suppression in the yield of hadrons with pT < 100 GeV/c in p(d)A collisions.

  16. Portable 543 nm length standard and magnetic-induced zero-crossing shift on length standard transition

    E-Print Network [OSTI]

    Shy,Jow-Tsong

    a convenient and objective length standard for use in both academic and industrial applications. Ever since the ve- locity of light in a vacuum was defined as 299 792 458 m/s in 1983,1 atom or molecule of the primary length-standard lasers,16 and some inter- comparisons were held thereafter.11,14 Therefore

  17. CHARACTERIZATION OF WILD PIG VEHICLE COLLISIONS

    SciTech Connect (OSTI)

    Mayer, J; Paul E. Johns, P

    2007-05-23T23:59:59.000Z

    Wild pig (Sus scrofa) collisions with vehicles are known to occur in the United States, but only minimal information describing these accidents has been reported. In an effort to better characterize these accidents, data were collected from 179 wild pig-vehicle collisions from a location in west central South Carolina. Data included accident parameters pertaining to the animals involved, time, location, and human impacts. The age structure of the animals involved was significantly older than that found in the population. Most collisions involved single animals; however, up to seven animals were involved in individual accidents. As the number of animals per collision increased, the age and body mass of the individuals involved decreased. The percentage of males was significantly higher in the single-animal accidents. Annual attrition due to vehicle collisions averaged 0.8 percent of the population. Wild pig-vehicle collisions occurred year-round and throughout the 24-hour daily time period. Most accidents were at night. The presence of lateral barriers was significantly more frequent at the collision locations. Human injuries were infrequent but potentially serious. The mean vehicle damage estimate was $1,173.

  18. NUCLEAR PROXIMITY FORCES

    E-Print Network [OSTI]

    Randrup, J.

    2011-01-01T23:59:59.000Z

    One might summarize of nuclear potential energy has beendegree of freedom) for the nuclear interaction between anyUniversity of California. Nuclear Proximity Forces 'I< at

  19. Nuclear scales

    SciTech Connect (OSTI)

    Friar, J.L.

    1998-12-01T23:59:59.000Z

    Nuclear scales are discussed from the nuclear physics viewpoint. The conventional nuclear potential is characterized as a black box that interpolates nucleon-nucleon (NN) data, while being constrained by the best possible theoretical input. The latter consists of the longer-range parts of the NN force (e.g., OPEP, TPEP, the {pi}-{gamma} force), which can be calculated using chiral perturbation theory and gauged using modern phase-shift analyses. The shorter-range parts of the force are effectively parameterized by moments of the interaction that are independent of the details of the force model, in analogy to chiral perturbation theory. Results of GFMC calculations in light nuclei are interpreted in terms of fundamental scales, which are in good agreement with expectations from chiral effective field theories. Problems with spin-orbit-type observables are noted.

  20. Nuclear winter

    SciTech Connect (OSTI)

    Ehrlich, A.

    1984-04-01T23:59:59.000Z

    The 13 speakers at the October 1983 Conference on the World After Nuclear War each contributed specialized knowledge to the climatic and biological effects of nuclear war. The author highlights the findings of the TTAPS (named for its authors) study and confirmation by Soviet scientists on the nuclear winter. Atmospheric consequences would come from debris blocking sunlight and creating conditions of cold and darkness that could preclude the continued existence of life. The biological consequences of cold and darkness would be reduced photosynthesis, devastating losses of food, damage and death from ionizing radiation, and a breakdown of ecosystems. Impacts on the human population would be intensified by a breakdown in social services. The author summarizes points of discussion during the conference. 4 references.

  1. Nuclear Physics

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of Science (SC)Integrated CodesTransparencyDOE Project TapsDOERecovery NuclearSensor NodesNuclear

  2. Exploiting Universality in Atoms with Large Scattering Lengths

    SciTech Connect (OSTI)

    Braaten, Eric

    2012-05-31T23:59:59.000Z

    The focus of this research project was atoms with scattering lengths that are large compared to the range of their interactions and which therefore exhibit universal behavior at sufficiently low energies. Recent dramatic advances in cooling atoms and in manipulating their scattering lengths have made this phenomenon of practical importance for controlling ultracold atoms and molecules. This research project was aimed at developing a systematically improvable method for calculating few-body observables for atoms with large scattering lengths starting from the universal results as a first approximation. Significant progress towards this goal was made during the five years of the project.

  3. Hydrogen atom in momentum space with a minimal length

    E-Print Network [OSTI]

    Djamil Bouaziz; Nourredine Ferkous

    2010-09-05T23:59:59.000Z

    A momentum representation treatment of the hydrogen atom problem with a generalized uncertainty relation,which leads to a minimal length ({\\Delta}X_{i})_{min}= \\hbar \\sqrt(3{\\beta}+{\\beta}'), is presented. We show that the distance squared operator can be factorized in the case {\\beta}'=2{\\beta}. We analytically solve the s-wave bound-state equation. The leading correction to the energy spectrum caused by the minimal length depends on \\sqrt{\\beta}. An upper bound for the minimal length is found to be about 10^{-9} fm.

  4. Inflationary universe in the presence of a minimal measurable length

    E-Print Network [OSTI]

    A. Mohammadi; Ahmed Farag Ali; T. Golanbari; A. Aghamohammadi; Kh. Saaidi; Mir Faizal

    2015-05-17T23:59:59.000Z

    In this paper, we will study the effect of having a minimum measurable length on inflationary cosmology. We will analyse the inflationary cosmology in the Jacobson approach. In this approach, gravity is viewed as an emergent thermodynamical phenomena. We will demonstrate that the existence of a minimum measurable length will modify the Friedmann equations in the Jacobson approach. We will use this modified Friedmann equation to analyse the effect of minimum measurable length scale on inflationary cosmology. This analysis will be performed using the Hamiltonian-Jacobi approach. We compare our results to recent data, and find that our model may agree with the recent data.

  5. Inflationary universe in the presence of a minimal measurable length

    E-Print Network [OSTI]

    Mohammadi, A; Golanbari, T; Aghamohammadi, A; Saaidi, Kh; Faizal, Mir

    2015-01-01T23:59:59.000Z

    In this paper, we will study the effect of having a minimum measurable length on inflationary cosmology. We will analyse the inflationary cosmology in the Jacobson approach. In this approach, gravity is viewed as an emergent thermodynamical phenomena. We will demonstrate that the existence of a minimum measurable length will modify the Friedmann equations in the Jacobson approach. We will use this modified Friedmann equation to analyse the effect of minimum measurable length scale on inflationary cosmology. This analysis will be performed using the Hamiltonian-Jacobi approach. We compare our results to recent data, and find that our model may agree with the recent data.

  6. Role of density dependent symmetry energy in nuclear stopping

    E-Print Network [OSTI]

    Karan Singh Vinayak; Suneel Kumar

    2011-07-27T23:59:59.000Z

    Information about the nuclear matter under the extreme conditions of temperature and density and the role of symmetry energy under these conditions is still a topic of crucial importance in the present day nuclear physics research. The multifragmentation, collective flow and the nuclear stopping is among the various rare phenomenon which can be observed in heavy-ion collisions at intermediate energies. The nuclear stopping, which is sensitive towards the symmetry energy has gained a lot of interest because it provides the possibility to examine the degree of thermalization or equilibration in the matter. Aim of the present study is to pin down the nuclear stopping for the different forms of density dependent symmetry energy

  7. A coarse entropy-rigidity theorem and discrete length-volume inequalities

    E-Print Network [OSTI]

    Kinneberg, Kyle Edward

    2014-01-01T23:59:59.000Z

    A discrete length-volume inequality . . . . . . . .v 3 Length-volume inequalities revisitedlength-volume inequality for cubes . . . . . . . . . . . .

  8. Jet measurements by the CMS experiment in pp and PbPb collisions

    E-Print Network [OSTI]

    Christof Roland for the CMS Collaboration

    2011-07-15T23:59:59.000Z

    The energy loss of fast partons traversing the strongly interacting matter produced in high-energy nuclear collisions is one of the most interesting observables to probe the nature of the produced medium. The multipurpose Compact Muon Solenoid (CMS) detector is well designed to measure these hard scattering processes with its high resolution calorimeters and high precision silicon tracker. Analyzing data from pp and PbPb collisions at a center-of-mass energy of 2.76 TeV parton energy loss is observed as a significant imbalance of dijet transverse momentum. To gain further understanding of the parton energy loss mechanism the redistribution of the quenched jet energy was studied using the transverse momentum balance of charged tracks projected onto the direction of the leading jet. In contrast to pp collisions, a large fraction the momentum balance for asymmetric jets is found to be carried by low momentum particles at large angular distance to the jet axis. Further, the fragmentation functions for leading and subleading jets were reconstructed and were found to be unmodified compared to measurements in pp collisions. The results yield a detailed picture of parton propagation in the hot QCD medium.

  9. Forward hadron production in ultraperipheral proton-heavy-ion collisions at the LHC and RHIC

    E-Print Network [OSTI]

    Gaku Mitsuka

    2015-03-12T23:59:59.000Z

    We discuss hadron production in the forward rapidity region in ultraperipheral proton-lead collisions at the LHC and proton-gold collisions at RHIC. Our discussion is based on the Monte Carlo simulations of the interactions of virtual photons emitted by a fast moving nucleus with a proton beam. We simulate the virtual photon flux with the STARLIGHT event generator and then particle production with the SOPHIA, DPMJET, and PYTHIA event generators. We show the rapidity distributions of charged and neutral particles, and the momentum distributions of neutral pions and neutrons at forward rapidities. According to the Monte Carlo simulations, we find large cross sections of ultraperipheral collisions for particle production especially in the very forward region, leading to substantial background contributions to investigations of collective nuclear effects and spin physics. Finally we can distinguish between proton-nucleus inelastic interactions and ultraperipheral collisions with additional requirements of either of the charged particles at midrapidity and a certain level of activities at negative forward rapidity.

  10. Suppression of Upsilon Production in d+Au and Au+Au Collisions at sqrt(s_NN) = 200 GeV

    E-Print Network [OSTI]

    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; 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; Y. Guo; A. Gupta; S. Gupta; W. Guryn; B. Haag; O. Hajkova; A. Hamed; L-X. Han; R. Haque; J. W. Harris; S. Heppelmann; K. Hill; 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. 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; 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; 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. G. Munhoz; 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; 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; N. Poljak; 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; 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; 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; 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; J. A. Vanfossen, Jr.; R. Varma; G. M. S. Vasconcelos; A. N. Vasiliev; R. Vertesi; F. Videbćk; 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; G. Wimsatt; 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

    2015-01-21T23:59:59.000Z

    We report measurements of Upsilon meson production in p+p, d+Au, and Au+Au collisions using the STAR detector at RHIC. We compare the Upsilon yield to the measured cross section in p+p collisions in order to quantify any modifications of the yield in cold nuclear matter using d+Au data and in hot nuclear matter using Au+Au data separated into three centrality classes. Our p+p measurement is based on three times the statistics of our previous result. We obtain a nuclear modification factor for Upsilon(1S+2S+3S) in the rapidity range |y|<1 in d+Au collisions of R_dAu = 0.79 +/- 0.24 (stat.) +/- 0.03 (sys.) +/- 0.10 (pp sys.). A comparison with models including shadowing and initial state parton energy loss indicates the presence of additional cold-nuclear matter suppression. Similarly, in the top 10% most-central Au+Au collisions, we measure a nuclear modification factor of R_AA=0.49 +/- 0.1 (stat.) +/- 0.02 (sys.) +/- 0.06 (pp sys.), which is a larger suppression factor than that seen in cold nuclear matter. Our results are consistent with complete suppression of excited-state Upsilon mesons in Au+Au collisions. The additional suppression in Au+Au is consistent with the level expected in model calculations that include the presence of a hot, deconfined Quark-Gluon Plasma. However, understanding the suppression seen in d+Au is still needed before any definitive statements about the nature of the suppression in Au+Au can be made.

  11. Stopping effects in U+U collisions with a beam energy of 520 MeV/nucleon

    E-Print Network [OSTI]

    Luo, Xiao-Feng; Shao, Ming; Wu, Ke-Jun; Li, Cheng; Chen, Hong-Fang

    2007-01-01T23:59:59.000Z

    A Relativistic Transport Model (ART1.0) is applied to simulate the stopping effects in tip-tip and body-body U+U collisions, at a beam kinetic energy of 520 MeV/nucleon. Our simulation results have demonstrated that both central collisions of the two extreme orientations can achieve full stopping, and also form a bulk of hot, dense nuclear matter with a sufficiently large volume and long duration, due to the largely deformed uranium nuclei. The nucleon sideward flow in the tip-tip collisions is nearly 3 times larger than that in body-body ones at normalized impact parameter $b/b_{max}EoS, respectively. The Cooling Storage Ring (CSR) External Target Facility (ETF) to be built at Lanzhou, China...

  12. Scaling Properties of Hyperon Production in Au + Au Collisions at sqrt sNN = 200 GeV

    SciTech Connect (OSTI)

    Adams, J.

    2006-06-08T23:59:59.000Z

    We present the scaling properties of Lambda, Xi, and their anti-particles produced at mid-rapidity in Au+Au collisions at RHIC at psNN = 200 GeV. The yield of multi-strange baryons per participant nucleon increases from peripheral to central collisions more rapidly than the Lambda yield, which appears to correspond to an increasing strange quark density of matter produced. The value of the strange phase space occupancy factor gamma s, obtained from a thermal model fit to the data, approaches unity for the most central collisions. We also show that the nuclear modification factors, RCP, of Lambda and Xi are consistent with each other and with that of protons in the transverse momentum range2.0< pT< 5.0 GeV/c. This scaling behaviour is consistent with a scenario of hadron formation from constituent quark degrees of freedom through quark recombination or coalescence.

  13. Energy dependence of pi-zero production in Cu+Cu collisions at sqrt(s_NN) = 22.4, 62.4, and 200 GeV

    E-Print Network [OSTI]

    PHENIX Collaboration; A. Adare

    2008-01-29T23:59:59.000Z

    Neutral pion transverse momentum (pT) spectra at mid-rapidity (|y| zero yields in p+p collisions scaled by the number of inelastic nucleon-nucleon collisions (Ncoll) at the respective energies, the pi-zero yields for pT \\ge 2 GeV/c in central Cu+Cu collisions at 62.4 and 200 GeV are suppressed, whereas an enhancement is observed at 22.4 GeV. A comparison with a jet quenching model suggests that final state parton energy loss dominates in central Cu+Cu collisions at 62.4 GeV and 200 GeV, while the enhancement at 22.4 GeV is consistent with nuclear modifications in the initial state alone.

  14. Suppression of high transverse momentum D mesons in central Pb--Pb collisions at $\\sqrt{s_{NN}}=2.76$ TeV

    E-Print Network [OSTI]

    ALICE Collaboration; B. Abelev; J. Adam; D. Adamová; A. M. Adare; M. M. Aggarwal; G. Aglieri Rinella; A. G. Agocs; A. Agostinelli; S. Aguilar Salazar; Z. Ahammed; N. Ahmad; A. Ahmad Masoodi; S. U. Ahn; A. Akindinov; D. Aleksandrov; B. Alessandro; R. Alfaro Molina; A. Alici; A. Alkin; E. Almaráz Avińa; J. Alme; T. Alt; V. Altini; S. Altinpinar; I. Altsybeev; C. Andrei; A. Andronic; V. Anguelov; J. Anielski; C. Anson; T. Anticic; F. Antinori; P. Antonioli; L. Aphecetche; H. Appelshäuser; N. Arbor; S. Arcelli; A. Arend; N. Armesto; R. Arnaldi; T. Aronsson; I. C. Arsene; M. Arslandok; A. Asryan; A. Augustinus; R. Averbeck; T. C. Awes; J. Äystö; M. D. Azmi; M. Bach; A. Badalŕ; Y. W. Baek; R. Bailhache; R. Bala; R. Baldini Ferroli; A. Baldisseri; A. Baldit; F. Baltasar Dos Santos Pedrosa; J. Bán; R. C. Baral; R. Barbera; F. Barile; G. G. Barnaföldi; L. S. Barnby; V. Barret; J. Bartke; M. Basile; N. Bastid; S. Basu; B. Bathen; G. Batigne; B. Batyunya; C. Baumann; I. G. Bearden; H. Beck; I. Belikov; F. Bellini; R. Bellwied; E. Belmont-Moreno; G. Bencedi; S. Beole; I. Berceanu; A. Bercuci; Y. Berdnikov; D. Berenyi; D. Berzano; L. Betev; A. Bhasin; A. K. Bhati; J. Bhom; N. Bianchi; L. Bianchi; C. Bianchin; J. Bielcík; J. Bielcíková; A. Bilandzic; S. Bjelogrlic; F. Blanco; F. Blanco; D. Blau; C. Blume; M. Boccioli; N. Bock; A. Bogdanov; H. Břggild; M. Bogolyubsky; L. Boldizsár; M. Bombara; J. Book; H. Borel; A. Borissov; S. Bose; F. Bossú; M. Botje; S. Böttger; B. Boyer; E. Braidot; P. Braun-Munzinger; M. Bregant; T. Breitner; T. A. Browning; M. Broz; R. Brun; E. Bruna; G. E. Bruno; D. Budnikov; H. Buesching; S. Bufalino; K. Bugaiev; O. Busch; Z. Buthelezi; D. Caballero Orduna; D. Caffarri; X. Cai; H. Caines; E. Calvo Villar; P. Camerini; V. Canoa Roman; G. Cara Romeo; W. Carena; F. Carena; N. Carlin Filho; F. Carminati; C. A. Carrillo Montoya; A. Casanova Díaz; J. Castillo Castellanos; J. F. Castillo Hernandez; E. A. R. Casula; V. Catanescu; C. Cavicchioli; C. Ceballos Sanchez; J. Cepila; P. Cerello; B. Chang; S. Chapeland; J. L. Charvet; S. Chattopadhyay; S. Chattopadhyay; I. Chawla; M. Cherney; C. Cheshkov; B. Cheynis; V. Chibante Barroso; D. D. Chinellato; P. Chochula; M. Chojnacki; S. Choudhury; P. Christakoglou; C. H. Christensen; P. Christiansen; T. Chujo; S. U. Chung; C. Cicalo; L. Cifarelli; F. Cindolo; J. Cleymans; F. Coccetti; F. Colamaria; D. Colella; G. Conesa Balbastre; Z. Conesa del Valle; P. Constantin; G. Contin; J. G. Contreras; T. M. Cormier; Y. Corrales Morales; P. Cortese; I. Cortés Maldonado; M. R. Cosentino; F. Costa; M. E. Cotallo; E. Crescio; P. Crochet; E. Cruz Alaniz; E. Cuautle; L. Cunqueiro; A. Dainese; H. H. Dalsgaard; A. Danu; K. Das; I. Das; D. Das; A. Dash; S. Dash; S. De; G. O. V. de Barros; A. De Caro; G. de Cataldo; J. de Cuveland; A. De Falco; D. De Gruttola; H. Delagrange; E. Del Castillo Sanchez; A. Deloff; V. Demanov; N. De Marco; E. Dénes; S. De Pasquale; A. Deppman; G. D Erasmo; R. de Rooij; M. A. Diaz Corchero; D. Di Bari; T. Dietel; C. Di Giglio; S. Di Liberto; A. Di Mauro; P. Di Nezza; R. Diviŕ; Ř. Djuvsland; A. Dobrin; T. Dobrowolski; I. Domínguez; B. Dönigus; O. Dordic; O. Driga; A. K. Dubey; L. Ducroux; P. Dupieux; A. K. Dutta Majumdar; M. R. Dutta Majumdar; D. Elia; D. Emschermann; H. Engel; H. A. Erdal; B. Espagnon; M. Estienne; S. Esumi; D. Evans; G. Eyyubova; D. Fabris; J. Faivre; D. Falchieri; A. Fantoni; M. Fasel; R. Fearick; A. Fedunov; D. Fehlker; L. Feldkamp; D. Felea; B. Fenton-Olsen; G. Feofilov; A. Fernández Téllez; A. Ferretti; R. Ferretti; J. Figiel; M. A. S. Figueredo; S. Filchagin; D. Finogeev; F. M. Fionda; E. M. Fiore; M. Floris; S. Foertsch; P. Foka; S. Fokin; E. Fragiacomo; M. Fragkiadakis; U. Frankenfeld; U. Fuchs; C. Furget; M. Fusco Girard; J. J. Gaardhřje; M. Gagliardi; A. Gago; M. Gallio; D. R. Gangadharan; P. Ganoti; C. Garabatos; E. Garcia-Solis; I. Garishvili; J. Gerhard; M. Germain; C. Geuna; M. Gheata; A. Gheata; B. Ghidini; P. Ghosh; P. Gianotti; M. R. Girard; P. Giubellino; E. Gladysz-Dziadus; P. Glässel; R. Gomez; E. G. Ferreiro; L. H. González-Trueba; P. González-Zamora; S. Gorbunov; A. Goswami; S. Gotovac; V. Grabski; L. K. Graczykowski; R. Grajcarek; A. Grelli; C. Grigoras; A. Grigoras; V. Grigoriev; S. Grigoryan; A. Grigoryan; B. Grinyov; N. Grion; P. Gros; J. F. Grosse-Oetringhaus; J. -Y. Grossiord; R. Grosso; F. Guber; R. Guernane; C. Guerra Gutierrez; B. Guerzoni; M. Guilbaud; K. Gulbrandsen; T. Gunji; R. Gupta; A. Gupta; H. Gutbrod; Ř. Haaland; C. Hadjidakis; M. Haiduc; H. Hamagaki; G. Hamar; B. H. Han; L. D. Hanratty; A. Hansen; Z. Harmanova; J. W. Harris; M. Hartig; D. Hasegan; D. Hatzifotiadou; A. Hayrapetyan; S. T. Heckel; M. Heide; H. Helstrup; A. Herghelegiu; G. Herrera Corral; N. Herrmann; K. F. Hetland

    2012-10-12T23:59:59.000Z

    The production of the prompt charm mesons $D^0$, $D^+$, $D^{*+}$, and their antiparticles, was measured with the ALICE detector in Pb-Pb collisions at the LHC, at a centre-of-mass energy $\\sqrt{s_{NN}}=2.76$ TeV per nucleon--nucleon collision. The $\\pt$-differential production yields in the range $2nuclear modification factor $R_{AA}$ with respect to a proton-proton reference obtained from the cross section measured at $\\sqrt{s}=7$ TeV and scaled to $\\sqrt{s}=2.76$ TeV. For the three meson species, $R_{AA}$ shows a suppression by a factor 3-4, for transverse momenta larger than 5 GeV/c in the 20% most central collisions. The suppression is reduced for peripheral collisions.

  15. Analysis of Wet Weather Related Collision Concentration Locations: Empirical Assessment of Continuous Risk Profile

    E-Print Network [OSTI]

    Oh, Soonmi; Chung, Koohong; Ragland, David R; Chan, Ching-Yao

    2009-01-01T23:59:59.000Z

    Analysis of Wet Weather Related Collision ConcentrationThe CRP plot displays wet weather related collision profilefactors responsible for wet weather related collisions is

  16. Partonic coalescence in relativistic heavy ion collisions

    E-Print Network [OSTI]

    Greco, V.; Ko, Che Ming; Levai, P.

    2003-01-01T23:59:59.000Z

    Using a covariant coalescence model, we study hadron production in relativistic heavy ion collisions from both soft partons in the quark-gluon plasma and hard partons in minijets. Including transverse flow of soft partons and independent...

  17. Hadron Production in Heavy Ion Collisions

    E-Print Network [OSTI]

    Helmut Oeschler; Hans Georg Ritter; Nu Xu

    2009-08-12T23:59:59.000Z

    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.

  18. Physics in Collision 2009 -- Kobe, Japan

    ScienceCinema (OSTI)

    Dr. Yuji Yamazaki

    2010-01-08T23:59:59.000Z

    Dr. Yuji Yamazaki, a host of the Physics in Collision 2009 conference, and Dr. Thomas Muller, who will host the conference in 2010, talk about PIC 2009 in Kobe, Japan.

  19. Collision of Polymers in a Vacuum

    E-Print Network [OSTI]

    J. M. Deutsch

    2010-10-12T23:59:59.000Z

    In a number of experimental situations, single polymer molecules can be suspended in a vacuum. Here collisions between such molecules are considered. The limit of high collision velocity is investigated numerically for a variety of conditions. The distribution of contact times, scattering angles, and final velocities are analyzed. In this limit, self avoiding chains are found to become highly stretched as they collide with each other, and have a distribution of scattering times that depends on the scattering angle. The velocity of the molecules after the collisions is similar to predictions of a model assuming thermal equilibration of molecules during the collision. The most important difference is a significant subset of molecules that inelastically scatter but do not substantially change direction.

  20. Nuclear Golf

    E-Print Network [OSTI]

    Hacker, Randi; Tsutsui, William

    2006-12-06T23:59:59.000Z

    Broadcast Transcript: Pay no attention to that nuclear warhead behind the 18th hole; just shout "Fore!" and drive your Titleist down the fairway. In a development that is bizarre even by North Korean standards, the country is making a move to sell...

  1. FEL GAIN LENGTH AND TAPER MEASUREMENTS AT LCLS

    E-Print Network [OSTI]

    Ratner, D.

    2010-01-01T23:59:59.000Z

    taper mea- surements from LCLS. We ?nd gain lengths of ? 2.9AND TAPER MEASUREMENTS AT LCLS ? D. Ratner † , A. Brachmann,et al. , First Results of the LCLS Laser-Heater Sys- tem,

  2. amyloid fibril length: Topics by E-print Network

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

    22 23 24 25 Next Page Last Page Topic Index 1 Intrinsic Linear Heterogeneity of Amyloid Beta Protein Fibrils Revealed by Higher Resolution Mass-per-length Determinations* Chemistry...

  3. Formation lengths of hadrons in lepto-production

    E-Print Network [OSTI]

    Levon Grigoryan

    2012-09-28T23:59:59.000Z

    The average formation lengths of the hadrons produced during the deep inelastic scattering (DIS) of leptons on protons are studied in the framework of the symmetric Lund model. It is shown that these formation lengths essentially depend on the electric charges of the hadron. For electro-production and charged current (CC) neutrino-production, the average formation lengths of positively charged particles are larger than those of negatively charged antiparticles. This situation is reversed for CC antineutrino-production. In all the mentioned cases, the main mechanism is the direct production of hadrons. The additional mechanism of hadron production, through the decay of resonances, is essential only for pions and leads to a decrease in the average formation lengths.

  4. Applying Vocal Tract Length Normalization to Meeting Recordings 

    E-Print Network [OSTI]

    Garau, Giulia; Renals, Steve; Hain, Thomas

    2005-01-01T23:59:59.000Z

    Vocal Tract Length Normalisation (VTLN) is a commonly used technique to normalise for inter-speaker variability. It is based on the speaker-specific warping of the frequency axis, parameterised by a scalar warp factor. ...

  5. Inferring the Rate-Length Law of Protein Folding

    E-Print Network [OSTI]

    Lane, Thomas J

    2013-01-01T23:59:59.000Z

    We investigate the rate-length scaling law of protein folding, a key undetermined scaling law in the analytical theory of protein folding. We demonstrate that chain length is a dominant factor determining folding times, and that the unambiguous determination of the way chain length corre- lates with folding times could provide key mechanistic insight into the folding process. Four specific proposed laws (power law, exponential, and two stretched exponentials) are tested against one an- other, and it is found that the power law best explains the data. At the same time, the fit power law results in rates that are very fast, nearly unreasonably so in a biological context. We show that any of the proposed forms are viable, conclude that more data is necessary to unequivocally infer the rate-length law, and that such data could be obtained through a small number of protein folding experiments on large protein domains.

  6. FEL GAIN LENGTH AND TAPER MEASUREMENTS AT LCLS

    E-Print Network [OSTI]

    Ratner, D.

    2010-01-01T23:59:59.000Z

    more than double the coherent, FEL power over the satura-FEL GAIN LENGTH AND TAPER MEASUREMENTS AT LCLS ? D.Figure 11: Post-saturation FEL pulse energy for a taper with

  7. Scaling of Anisotropic Flows in Intermediate Energy and Ultra-relativistic Heavy Ion Collisions

    E-Print Network [OSTI]

    Y. G. Ma

    2006-11-30T23:59:59.000Z

    Anisotropic flows ($v_2$ and $v_4$) of hadrons and light nuclear clusters are studied by a partonic transport model and nucleonic transport model, respectively, in ultra-relativistic and intermediate energy heavy ion collisions. Both number-of-constituent-quark scaling of hadrons, especially for $\\phi$ meson which is composed of strange quarks, and number-of-nucleon scaling of light nuclear clusters are discussed and explored for the elliptic flow ($v_2$). The ratios of $v_4/v_2^2$ of hadrons and nuclear clusters are, respectively, calculated and they show different constant values which are independent of transverse momentum. The above phenomena can be understood, respectively, by the coalescence mechanism in quark-level or nucleon-level.

  8. Hydrogen-atom spectrum under a minimal-length hypothesis

    E-Print Network [OSTI]

    Sandor Benczik; Lay Nam Chang; Djordje Minic; Tatsu Takeuchi

    2005-07-08T23:59:59.000Z

    The energy spectrum of the Coulomb potential with minimal length commutation relations $[X_i, P_j] = i\\hbar\\{\\delta_{ij}(1+\\beta P^2) + \\beta'P_iP_j\\}$ is determined both numerically and perturbatively for arbitrary values of $\\beta'/\\beta$ and angular momenta $\\ell$. The constraint on the minimal length scale from precision hydrogen spectroscopy data is of order of a few GeV$\

  9. Coulomb collision effects on linear Landau damping

    SciTech Connect (OSTI)

    Callen, J. D., E-mail: callen@engr.wisc.edu [University of Wisconsin, Madison, Wisconsin 53706-1609 (United States)

    2014-05-15T23:59:59.000Z

    Coulomb collisions at rate ? produce slightly probabilistic rather than fully deterministic charged particle trajectories in weakly collisional plasmas. Their diffusive velocity scattering effects on the response to a wave yield an effective collision rate ?{sub eff} ? ? and a narrow dissipative boundary layer for particles with velocities near the wave phase velocity. These dissipative effects produce temporal irreversibility for times t???1/?{sub eff} during Landau damping of a small amplitude Langmuir wave.

  10. Nuclear Forensics | National Nuclear Security Administration

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

    Forensics | National Nuclear Security Administration Facebook Twitter Youtube Flickr RSS People Mission Managing the Stockpile Preventing Proliferation Powering the Nuclear Navy...

  11. Nuclear Incident Team | National Nuclear Security Administration

    National Nuclear Security Administration (NNSA)

    Incident Team | National Nuclear Security Administration Facebook Twitter Youtube Flickr RSS People Mission Managing the Stockpile Preventing Proliferation Powering the Nuclear...

  12. Curved and diffuse interface effects on the nuclear surface tension

    E-Print Network [OSTI]

    V. M. Kolomietz; S. V. Lukyanov; A. I. Sanzhur

    2012-01-30T23:59:59.000Z

    We redefine the surface tension coefficient for a nuclear Fermi-liquid drop with a finite diffuse layer. Following Gibbs-Tolman concept, we introduce the equimolar radius R_e of sharp surface droplet at which the surface tension is applied and the radius of tension surface R_s which provides the minimum of the surface tension coefficient \\sigma. This procedure allows us to derive both the surface tension and the corresponding curvature correction (Tolman length) correctly for the curved and diffuse interface. We point out that the curvature correction depends significantly on the finite diffuse interface. This fact is missed in traditional nuclear considerations of curvature correction to the surface tension. We show that Tolman's length \\xi is negative for nuclear Fermi-liquid drop. The value of the Tolman length is only slightly sensitive to the Skyrme force parametrization and equals \\xi=-0.36 fm.

  13. Sequential melting of charmonium states in an expanding Quark Gluon Plasma and $J/?$ suppression at RHIC and LHC energy collisions

    E-Print Network [OSTI]

    A. K. Chaudhuri

    2008-07-04T23:59:59.000Z

    We have developed a hydrodynamic model to study sequential melting of charmonium states in an expanding QGP medium. According to the initial fluid temperature profile, $J/\\psi$'s are randomly distributed in the transverse plane. As the fluid evolve in time, the free streaming $J/\\psi$'s are suppressed if the local fluid temperature exceed a critical temperature. PHENIX data on the centrality dependence of $J/\\psi$ suppression in Au+Au collisions at mid-rapidity are explained by sequential melting of the charmonium states, $\\chi_c$, $\\psi\\prime$ and $J/\\psi$, in the expanding medium. The critical temperatures $T_{J/\\psi} \\approx2.09T_c$ and $T_\\chi=T_{\\chi_c}=T_{\\psi\\prime} \\approx 1.1T_c$ agree with lattice motivated calculations. The feed-down fraction $F$ depend on whether the cold nuclear matter effect is included or not. It changes from $F=0.3$ with cold nuclear matter effect included to $F=0.5$ when the effect is neglected. Model fails to reproduce the PHENIX data on the centrality dependence of $J/\\psi$ suppression in Cu+Cu collisions at mid-rapidity, indicating that the mechanism of $J/\\psi$ suppression is different in Au+Au and in Cu+Cu collisions. We also use the model to predict for the centrality dependence of $J/\\psi$ suppression in Pb+Pb collisions at LHC energy, $\\sqrt{s}$=5500 GeV. In LHC energy, $J/\\psi$'s are more suppressed in mid central collisions than in Au+Au collisions at RHIC energy.

  14. Antenna mechanism of length control of actin cables

    E-Print Network [OSTI]

    Lishibanya Mohapatra; Bruce L. Goode; Jane Kondev

    2015-05-02T23:59:59.000Z

    Actin cables are linear cytoskeletal structures that serve as tracks for myosin-based intracellular transport of vesicles and organelles in both yeast and mammalian cells. In a yeast cell undergoing budding, cables are in constant dynamic turnover yet some cables grow from the bud neck toward the back of the mother cell until their length roughly equals the diameter of the mother cell. This raises the question: how is the length of these cables controlled? Here we describe a novel molecular mechanism for cable length control inspired by recent experimental observations in cells. This antenna mechanism involves three key proteins: formins, which polymerize actin, Smy1 proteins, which bind formins and inhibit actin polymerization, and myosin motors, which deliver Smy1 to formins, leading to a length-dependent actin polymerization rate. We compute the probability distribution of cable lengths as a function of several experimentally tuneable parameters such as the formin-binding affinity of Smy1 and the concentration of myosin motors delivering Smy1. These results provide testable predictions of the antenna mechanism of actin-cable length control.

  15. WORKSHOP ON NUCLEAR DYNAMICS

    E-Print Network [OSTI]

    Myers, W.D.

    2010-01-01T23:59:59.000Z

    L. Wilets, "Theories of Nuclear Fission", Clarendon Press,of the nuclear force, result in lower calculated fission

  16. National Nuclear Security Administration

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

    FROM: SUBJECT: USIUK Memorandum of Understanding between National Nuclear Security Administration's (NNSA) Associate Administrator for Defense Nuclear Security (AADNS)...

  17. Dynamic nuclear polarization in biomolecular solid state NMR : methods and applications in peptides and membrane proteins

    E-Print Network [OSTI]

    Bajaj, Vikram Singh

    2007-01-01T23:59:59.000Z

    Solid state NMR can probe structure and dynamics on length scales from the atomic to the supramolecular. However, low sensitivity limits its application in macromolecules. NMR sensitivity can be improved by dynamic nuclear ...

  18. INSTRUCTIONS FOR SUBMITTING NUCLEAR

    E-Print Network [OSTI]

    waste management proceedings. Keywords Nuclear, nuclear power plant, spent fuel, nuclear waste, data of Submitted Data 3 NUCLEAR POWER PLANT DATA REQUESTS 6 A. Environmental Impacts 6 B. Spent Fuel Generation 8 C. Spent Nuclear Fuel Storage 9 D. Spent Nuclear Fuel Transport and Disposal Issues 10 E. Interim Spent

  19. Energy Dependence of the Transverse Momentum Distributions of Charged Particles in pp Collisions Measured by ALICE

    E-Print Network [OSTI]

    ALICE Collaboration

    2014-11-04T23:59:59.000Z

    Differential cross sections of charged particles in inelastic pp collisions as a function of $p_{\\rm T}$ have been measured at $\\sqrt{s}=$ 0.9, 2.76 and 7 TeV at the LHC. The $p_{\\rm T}$ spectra are compared to NLO-pQCD calculations. Though the differential cross section for an individual $\\sqrt{s}$ cannot be described by NLO-pQCD, the relative increase of cross section with $\\sqrt{s}$ is in agreement with NLO-pQCD. Based on these measurements and observations, procedures are discussed to construct pp reference spectra at $\\sqrt{s} =$ 2.76 and 5.02 TeV up to $p_{\\rm T}$ = 50 GeV/$c$ as required for the calculation of the nuclear modification factor in nucleus-nucleus and proton-nucleus collisions.

  20. Nuclear multifragmentation and fission: similarity and differences

    E-Print Network [OSTI]

    V. Karnaukhov; H. Oeschler; S. Avdeyev; V. Rodionov; V. Kirakosyan; A. Simonenko; P. Rukoyatkin; A. Budzanowski; W. Karcz; I. Skwirczynska; B. Czech; L. Chulkov; E. Kuzmin; E. Norbeck; A. Botvina

    2006-02-10T23:59:59.000Z

    Thermal multifragmentation of hot nuclei is interpreted as the nuclear liquid--fog phase transition deep inside the spinodal region. The experimental data for p(8.1GeV) + Au collisions are analyzed. It is concluded that the decay process of hot nuclei is characterized by two size parameters: transition state and freeze-out volumes. The similarity between dynamics of fragmentation and ordinary fission is discussed. The IMF emission time is related to the mean rupture time at the multi-scission point, which corresponds to the kinetic freeze-out configuration.

  1. Pseudo-critical clusterization in nuclear multifragmentation

    E-Print Network [OSTI]

    Diego Gruyer; J. D. Frankland; R. Botet; M. Ploszajczak; E. Bonnet; A. Chbihi; P. Marini

    2013-08-24T23:59:59.000Z

    In this contribution we show that the biggest fragment charge distribution in central collisions of Xe+Sn leading to multifragmentation is an admixture of two asymptotic distributions observed for the lowest and highest bombarding energies. The evolution of the relative weights of the two components with bombarding energy is shown to be analogous to that observed as a function of time for the largest cluster produced in irreversible aggregation for a finite system. We infer that the size distribution of the largest fragment in nuclear multifragmentation is also characteristic of the time scale of the process, which is largely determined by the onset of radial expansion in this energy range.

  2. Nuclear spectroscopic studies. Progress report

    SciTech Connect (OSTI)

    Bingham, C.R.; Guidry, M.W.; Riedinger, L.L.; Sorensen, S.P.

    1993-02-08T23:59:59.000Z

    The Nuclear Physics group at the University of Tennessee, Knoxville is involved in several aspects of heavy-ion physics including both nuclear structure and reaction mechanisms. While our main emphasis is on experimental problems involving heavy-ion accelerators, we have maintained a strong collaboration with several theorists in order to best pursue the physics of our measurements. During the last year we have led several experiments at the Holifield Heavy Ion Research Facility and participated in others at Argonne National Laboratory. Also, we continue to be very active in the collaboration to study ultra-relativistic heavy ion physics utilizing the SPS accelerator at CERN in Geneva, Switzerland and in a RHIC detector R&D project. Our experimental work is in four broad areas: (1) the structure of nuclei at high angular momentum, (2) heavy-ion induced transfer reactions, (3) the structure of nuclei far from stability, and (4) ultra-relativistic heavy-ion physics. The results of studies in these particular areas will be described in this document in sections IIA, IIB, IIC, and IID, respectively. Areas (1), (3), and (4) concentrate on the structure of nuclear matter in extreme conditions of rotational motion, imbalance of neutrons and protons, or very high temperature and density. Area (2) pursues the transfer of nucleons to states with high angular momentum, both to learn about their structure and to understand the transfer of particles, energy, and angular momentum in collisions between heavy ions. An important component of our program is the strong emphasis on the theoretical aspects of nuclear structure and reactions.

  3. Neutral Pion Production in Au+Au Collisions at sqrt sNN = 200 GeV

    SciTech Connect (OSTI)

    STAR Collaboration; Abelev, B. I.

    2009-10-23T23:59:59.000Z

    The results of mid-rapidity (0 < y < 0.8) neutral pion spectra over an extended transverse momentum range (1 < p{sub T} < 12 GeV/c) in {radical}s{sub NN} = 200 GeV Au+Au collisions, measured by the STAR experiment, are presented. The neutral pions are reconstructed from photons measured either by the STAR Barrel Electro-Magnetic Calorimeter (BEMC) or by the Time Projection Chamber (TPC) via tracking of conversion electron-positron pairs. Our measurements are compared to previously published {pi}{sup {+-}} and {pi}{sup 0} results. The nuclear modification factors R{sub CP} and R{sub AA} of {pi}{sup 0} are also presented as a function of p{sub T}. In the most central Au+Au collisions, the binary collision scaled {pi}{sup 0} yield at high p{sub T} is suppressed by a factor of about 5 compared to the expectation from the yield of p+p collisions. Such a large suppression is in agreement with previous observations for light quark mesons and is consistent with the scenario that partons suffer considerable energy loss in the dense medium formed in central nucleus-nucleus collisions at RHIC.

  4. Suppression of upsilon Production in d + Au and Au + Au collisions at root s=200 GeV

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

    Adamczyk, L.; STAR Collaboration

    2014-07-01T23:59:59.000Z

    We report measurements of Upsilon meson production in p + p, d +Au, and Au+Aucollisions using the STAR detector at RHIC. We compare the Upsilon yield to the measured cross section in p + p collisions in order to quantify any modifications of the yield in cold nuclear matter using d +Au data and in hot nuclear matter using Au+Au data separated into three centrality classes. Our p +p measurement is based on three times the statistics of our previous result. We obtain a nuclear modification factor for Upsilon (1S + 2S + 3S) in the rapidity range |y| dAu = 0.79 ± 0.24(stat.) ± 0.03(syst.) ± 0.10(p + p syst.). A comparison with models including shadowing and initial state part on energy loss indicates the presence of additional cold-nuclear matter suppression. Similarly, in the top 10% most-central Au + Au collisions, we measure a nuclear modification factor of R AA = 0.49 ±0.1(stat.) ±0.02(syst.) ±0.06(p + p syst.), which is a larger suppression factor than that seen in cold nuclear matter. Our results are consistent with complete suppression of excited-state Upsilon mesons in Au + Au collisions. The additional suppression in Au + Au is consistent with the level expected in model calculations that include the presence of a hot, deconfined Quark–Gluon Plasma. However, understanding the suppression seen in d + Au is still needed before any definitive statements about the nature of the suppression in Au + Au can be made.

  5. Feedback Mechanism for Microtubule Length Regulation by Stathmin Gradients

    E-Print Network [OSTI]

    Maria Zeitz; Jan Kierfeld

    2014-12-09T23:59:59.000Z

    We formulate and analyze a theoretical model for the regulation of microtubule (MT) polymerization dynamics by the signaling proteins Rac1 and stathmin. In cells, the MT growth rate is inhibited by cytosolic stathmin, which, in turn, is inactivated by Rac1. Growing MTs activate Rac1 at the cell edge, which closes a positive feedback loop. We investigate both tubulin sequestering and catastrophe promotion as mechanisms for MT growth inhibition by stathmin. For a homogeneous stathmin concentration in the absence of Rac1, we find a switch-like regulation of the MT mean length by stathmin. For constitutively active Rac1 at the cell edge, stathmin is deactivated locally, which establishes a spatial gradient of active stathmin. In this gradient, we find a stationary bimodal MT length distributions for both mechanisms of MT growth inhibition by stathmin. One subpopulation of the bimodal length distribution can be identified with fast growing and long pioneering MTs in the region near the cell edge, which have been observed experimentally. The feedback loop is closed through Rac1 activation by MTs. For tubulin sequestering by stathmin, this establishes a bistable switch with two stable states: one stable state corresponds to upregulated MT mean length and bimodal MT length distributions, i.e., pioneering MTs; the other stable state corresponds to an interrupted feedback with short MTs. Stochastic effects as well as external perturbations can trigger switching events. For catastrophe promoting stathmin we do not find bistability.

  6. Nuclear photonics

    SciTech Connect (OSTI)

    Habs, D.; Guenther, M. M.; Jentschel, M.; Thirolf, P. G. [Ludwig-Maximilians-Universitaet Muenchen, D-85748 Garching (Germany); Max Planck Institut fuer Quantenoptik, D-85748 Garching (Germany); Institut Laue-Langevin, F-38042 Grenoble (Germany); Ludwig-Maximilians-Universitaet Muenchen, D-85748 Garching (Germany)

    2012-07-09T23:59:59.000Z

    With the planned new {gamma}-beam facilities like MEGa-ray at LLNL (USA) or ELI-NP at Bucharest (Romania) with 10{sup 13}{gamma}/s and a band width of {Delta}E{gamma}/E{gamma} Almost-Equal-To 10{sup -3}, a new era of {gamma} beams with energies up to 20MeV comes into operation, compared to the present world-leading HI{gamma}S facility at Duke University (USA) with 10{sup 8}{gamma}/s and {Delta}E{gamma}/E{gamma} Almost-Equal-To 3 Dot-Operator 10{sup -2}. In the long run even a seeded quantum FEL for {gamma} beams may become possible, with much higher brilliance and spectral flux. At the same time new exciting possibilities open up for focused {gamma} beams. Here we describe a new experiment at the {gamma} beam of the ILL reactor (Grenoble, France), where we observed for the first time that the index of refraction for {gamma} beams is determined by virtual pair creation. Using a combination of refractive and reflective optics, efficient monochromators for {gamma} beams are being developed. Thus, we have to optimize the total system: the {gamma}-beam facility, the {gamma}-beam optics and {gamma} detectors. We can trade {gamma} intensity for band width, going down to {Delta}E{gamma}/E{gamma} Almost-Equal-To 10{sup -6} and address individual nuclear levels. The term 'nuclear photonics' stresses the importance of nuclear applications. We can address with {gamma}-beams individual nuclear isotopes and not just elements like with X-ray beams. Compared to X rays, {gamma} beams can penetrate much deeper into big samples like radioactive waste barrels, motors or batteries. We can perform tomography and microscopy studies by focusing down to {mu}m resolution using Nuclear Resonance Fluorescence (NRF) for detection with eV resolution and high spatial resolution at the same time. We discuss the dominating M1 and E1 excitations like the scissors mode, two-phonon quadrupole octupole excitations, pygmy dipole excitations or giant dipole excitations under the new facet of applications. We find many new applications in biomedicine, green energy, radioactive waste management or homeland security. Also more brilliant secondary beams of neutrons and positrons can be produced.

  7. Isospin Effects in Heavy-Ion Collisions: Some Results From CHIMERA Experiments At LNS And Perspectives With Radioactive Beams

    SciTech Connect (OSTI)

    Cardella, G.; De Filippo, E.; Pagano, A.; Papa, M.; Pirrone, S.; Verde, G. [INFN, Sez di Catania, Via S. Sofia 64-95123 Catania (Italy); Amorini, F.; Cavallaro, S.; Lombardo, I.; Porto, F.; Rizzo, F.; Russotto, P. [INFN Lab. Naz. del Sud, Via S. Sofia 44-95123 Catania (Italy); Dep. of Phys. and Astr. Univ. Catania Via S. Sofia 64-95123 Catania (Italy); Anzalone, A.; Maiolino, C. [INFN Lab. Naz. del Sud, Via S. Sofia 44-95123 Catania (Italy); Arena, N.; Geraci, E.; Grassi, L.; Lo Nigro, S.; Politi, G. [INFN, Sez di Catania, Via S. Sofia 64-95123 Catania (Italy); Dep. of Phys. and Astr. Univ. Catania Via S. Sofia 64-95123 Catania (Italy); Auditore, L. [INFN and Dep. of Phys. Univ. Messina (Italy)] (and others)

    2009-05-04T23:59:59.000Z

    CHIMERA is a 4{pi} multidetector for charged particles available at Laboratori Nazionali del Sud (INFN-LNS). A new method to measure the time scale of the emission of nuclear fragments is described, together with some applications in the field of the isospin dynamics of heavy-ion collisions. Competition between fusion-like and binary reactions near the energy threshold for nuclear multifragmentation is discussed. Opportunities are pointed out to use the detector at low and intermediate energies using the kinematical-coincidence method.

  8. Collision-free and Smooth Trajectory Computation in Cluttered Environments and Liangjun Zhang 2

    E-Print Network [OSTI]

    North Carolina at Chapel Hill, University of

    wiper. Left: a jerky, piecewise lin- ear collision-free path for the wiper. Right: a smooth collision

  9. Kaonic hydrogen atom and kaon-proton scattering length

    E-Print Network [OSTI]

    Y. Yan

    2009-05-29T23:59:59.000Z

    Kaonic hydrogen is studied with various realistic potentials in an accurate numerical approach based on Sturmian functions. The kaon-proton scattering length extracted from the 1s energy shift of the kaonic hydrogen by applying the Deser-Trueman formula is severely inconsistent with the one derived by directly solving the scattering Schoedinger equation. We pay special attention to the recent measurement of the energy shift and decay width of the 1s kaonic hydrogen state by the DEAR Collaboration. After taking into account the large discrepancy between the extracted and directly-evaluated scattering lengths, we found theoretical predictions of most chiral SU(3) based models for the kaonic hydrogen decay width are consistent with the DEAR data. We warn the SIDDHARTA collaboration that it may not be reasonable to extract kaon-nucleon scattering lengths, by using the Coulomb-interaction corrected Deser-Truemab formula, from the planned measurement of kaonic hydrogen.

  10. Critical Waves and the Length Problem of Biology

    E-Print Network [OSTI]

    Laughlin, R B

    2015-01-01T23:59:59.000Z

    It is pointed out that the mystery of how biological systems measure their lengths vanishes away if one premises that they have discovered a way to generate linear waves analogous to compressional sound. These can be used to detect length at either large or small scales using echo timing and fringe counting. It is shown that suitable linear chemical potential waves can, in fact, be manufactured by tuning to criticality conventional reaction-diffusion with a small number substances. Min oscillations in E. coli are cited as precedent resonant length measurement using chemical potential waves analogous to laser detection. Mitotic structures in eucaryotes are identified as candidates for such an effect at higher frequency. The engineering principle is shown to be very general and functionally the same as that used by hearing organs. PNAS Significance Statement: This paper invokes physical principles to address the question of how living things might use reaction-diffusion to measure out and regulate the many thou...

  11. Pumping current of a Luttinger liquid with finite length

    E-Print Network [OSTI]

    Sebastián Franchino Vińas; Pablo Pisani; Mariano Salvay

    2012-03-16T23:59:59.000Z

    We study transport properties in a Tomonaga-Luttinger liquid in the presence of two time-dependent point like weak impurities, taking into account finite-length effects. By employing analytical methods and performing a perturbation theory, we compute the backscattering pumping current (I_bs) in different regimes which can be established in relation to the oscillatory frequency of the impurities and to the frequency related to the length and the renormalized velocity (by the electron-electron interactions) of the charge density modes. We investigate the role played by the spatial position of the impurity potentials. We also show how the previous infinite length results for I_bs are modified by the finite size of the system.

  12. Security and Use Control of Nuclear Explosives and Nuclear Weapons...

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

    4C, Security and Use Control of Nuclear Explosives and Nuclear Weapons by LtCol Karl Basham Functional areas: Nuclear Explosives, Nuclear Weapons, Security The Order establishes...

  13. Nuclear Dependence of the Production of \\Upsilon Resonances at 800 GeV D. M. Alde, H. W. Baer, T. A. Carey, G. T. Garvey, A. Klein,

    E-Print Network [OSTI]

    , particularly in connection with J=/ production in high­energy heavy ion collisions. 1\\Gamma6 Nuclear dependenceNuclear Dependence of the Production of \\Upsilon Resonances at 800 GeV D. M. Alde, H. W. Baer, T. A. Barlett, G. W. Hoffmann University of Texas, Austin, Texas 78712 1 #12; Abstract The yields of the 1S

  14. Determining the density dependence of the nuclear symmetry energy using heavy-ion reactions

    E-Print Network [OSTI]

    Lie-Wen Chen; Che Ming Ko; Bao-An Li; Gao-Chan Yong

    2007-11-12T23:59:59.000Z

    We review recent progress in the determination of the subsaturation density behavior of the nuclear symmetry energy from heavy-ion collisions as well as the theoretical progress in probing the high density behavior of the symmetry energy in heavy-ion reactions induced by high energy radioactive beams. We further discuss the implications of these results for the nuclear effective interactions and the neutron skin thickness of heavy nuclei.

  15. Phase diagram for the asymmetric nuclear matter in the multifragmentation model

    E-Print Network [OSTI]

    G. Chaudhuri; S. Das Gupta

    2009-08-11T23:59:59.000Z

    We assume that, in equilibrium, nuclear matter at reduced density and moderate finite temperature, breaks up into many fragments. A strong support to this assumption is provided by date accumulated from intermediate energy heavy ion collisions. The break-up of hot and expanded nuclear matter according to rules of equilibrium statistical mechanics is the multifragmentation model. The model gives a first order phase transition. This is studied in detail here. Phase-equilibrium lines for different degrees of asymmetry are computed.

  16. Radiation re-solution of fission gas in non-oxide nuclear fuel

    SciTech Connect (OSTI)

    Christopher Matthews; Daniel Schwen; Andrew C. Klein

    2014-12-01T23:59:59.000Z

    Renewed interest in fast nuclear reactors is creating a need for better understanding of fission gas bubble behavior in non-oxide fuels to support very long fuel lifetimes. Collisions between fission fragments and their subsequent cascades can knock fission gas atoms out of bubbles and back into the fuel lattice. We showed that these collisions can be treated as using the so-called ‘‘homogenous’’ atom-by-atom re-solution theory and calculated using the Binary Collision Approximation code 3DOT. The calculations showed that there is a decrease in the re-solution parameter as bubble radius increases until about 50 nm, at which the re-solution parameter stays nearly constant. Furthermore, our model shows ion cascades created in the fuel result in many more implanted fission gas atoms than collisions directly with fission fragments. This calculated re-solution parameter can be used to find a re-solution rate for future bubble simulations.

  17. FEL GAIN LENGTH AND TAPER MEASUREMENTS AT LCLS

    SciTech Connect (OSTI)

    Ratner, D.; Fawley, W. M.; Brachmann, A.; Decker, F.J.; Ding, Y.; Dowell, D.; Emma, P.; Frisch, J.; Gilevich, S.; Hays, G.; Hering, P.; Huang, Z.; Loos, H.; Miahnahri, A.; Nuhn, H.D.; Turner, J.; Welch, J.; White, W.; Wu, J.; Xiang, D.; Yocky, G.; Fawley, W. M.

    2009-08-14T23:59:59.000Z

    We present experimental studies of the gain length and saturation power level from 1.5 nm to 1.5 Angstroms at the Linac Coherent Light Source (LCLS). By disrupting theFEL process with an orbit kick, we are able to measure the X-ray intensity as a function of undulator length. This kick method is cross-checked with the method of removing undulator sections. We also study the FEL-induced electron energy loss after saturation to determine the optimal taper of the undulator K values. The experimental results are compared to theory and simulations.

  18. Measurements of phi meson production in relativistic heavy-ion collisions at RHIC

    SciTech Connect (OSTI)

    STAR Coll

    2009-06-16T23:59:59.000Z

    We present results for the measurement of {phi} meson production via its charged kaon decay channel {phi} {yields} K{sup +}K{sup -} in Au + Au collisions at {radical}s{sub NN} = 62.4, 130, and 200 GeV, and in p + p and d + Au collisions at {radical}s{sub NN} = 200 GeV from the STAR experiment at the BNL Relativistic Heavy Ion Collider (RHIC). The midrapidity (|y| < 0.5) {phi} meson transverse momentum (p{sub T}) spectra in central Au + Au collisions are found to be well described by a single exponential distribution. On the other hand, the p{sub T} spectra from p + p, d + Au and peripheral Au + Au collisions show power-law tails at intermediate and high p{sub T} and are described better by Levy distributions. The constant {phi}/K{sup -} yield ratio vs beam species, collision centrality and colliding energy is in contradiction with expectations from models having kaon coalescence as the dominant mechanism for {phi} production at RHIC. The {Omega}/{phi} yield ratio as a function of p{sub T} is consistent with a model based on the recombination of thermal s quarks up to p{sub T} {approx} 4 GeV/c, but disagrees at higher transverse momenta. The measured nuclear modification factor, R{sub dAu}, for the {phi} meson increases above unity at intermediate p{sub T}, similar to that for pions and protons, while R{sub AA} is suppressed due to the energy loss effect in central Au + Au collisions. Number of constituent quark scaling of both R{sub cp} and v{sub 2} for the {phi} meson with respect to other hadrons in Au + Au collisions at {radical}s{sub NN} = 200 GeV at intermediate p{sub T} is observed. These observations support quark coalescence as being the dominant mechanism of hadronization in the intermediate p{sub T} region at RHIC.

  19. Nuclear shadowing and prompt photons at relativistic hadron colliders

    E-Print Network [OSTI]

    C. Brenner Mariotto; V. P. Goncalves

    2008-08-26T23:59:59.000Z

    The production of prompt photons at high energies provides a direct probe of the dynamics of the strong interactions. In particular, one expect that it could be used to constrain the behavior of the nuclear gluon distribution in $pA$ and $AA$ collisions. In this letter we investigate the influence of nuclear effects in the production of prompt photons and estimate the transverse momentum dependence of the nuclear ratios $R_{pA} = {\\frac{d\\sigma (pA)}{dy d^2 p_T}} / A {\\frac{d\\sigma (pp)}{dy d^2 p_T}}$ and $R_{AA} = {\\frac{d\\sigma (AA)}{dy d^2 p_T}} / A^2 {\\frac{d\\sigma (pp)}{dy d^2 p_T}}$ at RHIC and LHC energies. We demonstrate that the study of these observables can be useful to determine the magnitude of the shadowing and antishadowing effects in the nuclear gluon distribution.

  20. Experimental signals of the first phase transition of nuclear matter

    E-Print Network [OSTI]

    B. Borderie

    2001-02-26T23:59:59.000Z

    Vaporized and multifragmenting sources produced in heavy ion collisions at intermediate energies are good candidates to investigate the phase diagram of nuclear matter. The properties of highly excited nuclear sources which undergo a simultaneous disassembly into particles are found to sign the presence of a gas phase. For heavy nuclear sources produced in the Fermi energy domain, which undergo a simultaneous disassembly into particles and fragments, a fossil signal (fragment size correlations) reveals the origin of multifragmentation:spinodal instabilities which develop in the unstable coexistence region of the phase diagram of nuclear matter. Studies of fluctuations give a direct signature of a first order phase transition through measurements of a negative microcanonical heat capacity.

  1. atomic collision physics: Topics by E-print Network

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

    via condensate collisions Quantum Physics (arXiv) Summary: We perform a theoretical analysis of atomic four-wave mixing via a collision of two Bose-Einstein condensates of...

  2. Nuclear Astrophysics

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOnItemResearch > TheNuclear Astrophysics One of the great scientific challenges is

  3. Nuclear Forensics

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOnItemResearch > TheNuclear Astrophysics One of the great scientific

  4. Nuclear Energy!

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of Science (SC)Integrated CodesTransparencyDOE Project TapsDOE Directives,838Nuclear Detectionmore

  5. Nuclear Nonproliferation,

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of Science (SC)Integrated CodesTransparencyDOE Project TapsDOERecovery NuclearSensor Nodes for

  6. NUCLEAR ENERGY

    Office of Environmental Management (EM)

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742 33Frequently Asked QuestionsDepartment of Energyof Energy NREL:Education &NTSF NUCLEAR

  7. Dynamics of $K^+$ Production in Heavy Ion Collisions close to Threshold

    E-Print Network [OSTI]

    Christoph Hartnack

    2005-07-01T23:59:59.000Z

    In this article the production of $K^+$ at energies close to the threshold is studied in detail. The production mechanisms, the influence of in-medium effects, cross sections, the nuclear equation of state and the dynamics of the nucleons on the kaon dynamics are discussed. A special regard will be taken on the collision of Au+Au at 1.5 GeV, a reaction that has recently been analyzed in detail by experiments performed by the KaoS and FOPI collaborations at the SIS accelerator at GSI.

  8. Jet Quenching in Heavy-Ion Collisions - The Transition Era from RHIC to LHC

    E-Print Network [OSTI]

    Barbara Betz

    2012-11-26T23:59:59.000Z

    A status report on the jet quenching physics in heavy-ion collisions is given as it appears after more than 10 years of collecting and analysing data at the Relativistic Heavy Ion Collider (RHIC) and ~1.5 years of physics at the Large Hadron Collider (LHC). The (theoretical) predictions and expectations before the start of the LHC program are contrasted with the most recent experimental results, focussing on the nuclear modification factor R_{AA}, the elliptic flow v_2 of high-p_T particles, and on the problem of initial conditions.

  9. Free magnetized knots of parity-violating deconfined matter in heavy-ion collisions

    E-Print Network [OSTI]

    M. N. Chernodub

    2010-02-07T23:59:59.000Z

    We show that the local parity violation in the quark-gluon plasma supports existence of free (meta)stable knots of deconfined hot quark matter stabilized by superstrong magnetic fields. The magnetic field in the knots resembles the spheromak plasma state of the magnetic confinement approach to nuclear fusion. The size of the knot is quantized, being inversely proportional to the chiral conductivity of the quark-gluon plasma. The parity symmetry is broken inside the knot. Particles produced in the decays of the knots have unusual azimuthal distribution and specific flavor content. We argue that these knots may be created in noncentral heavy-ion collisions.

  10. Free magnetized knots of parity-violating deconfined matter in heavy-ion collisions

    E-Print Network [OSTI]

    Chernodub, M N

    2010-01-01T23:59:59.000Z

    We show that the local parity violation in the quark-gluon plasma supports existence of free (meta)stable knots of deconfined hot quark matter stabilized by superstrong magnetic fields. The magnetic field in the knots resembles the spheromak plasma state of the magnetic confinement approach to nuclear fusion. The size of the knot is quantized, being inversely proportional to the chiral conductivity of the quark-gluon plasma. The parity symmetry is broken inside the knot. Particles produced in the decays of the knots have unusual azimuthal distribution and specific flavor content. We argue that these knots may be created in noncentral heavy-ion collisions.

  11. Particle production in proton-proton collisions

    E-Print Network [OSTI]

    M. T. Ghoneim; M. T. Hussein; F. H. Sawy

    2014-10-27T23:59:59.000Z

    In this work, we present a study of particle production in proton-proton collisions using data that are collected from many experiments of relative wide range of reaction energies. These data include production of pions and heavier particles; like keons and lambda hyperons. Proton-proton collision is a simple system to investigate and to be considered a starting point that guides to more complicated processes of production in the proton-nucleus and the nucleus-nucleus collisions. In this paper, we are interested in the mechanisms that describe the process of particle production over a wide range of interaction energy, and how the physics of production changes with changing energy. Besides, this work may raise a question: are heavier particles than pions produced via the same mechanism(s) of producing pions, or these are created differently, being different in masses and other physical properties?

  12. Nuclear reactor engineering

    SciTech Connect (OSTI)

    Glasstone, S.; Sesonske, A.

    1981-01-01T23:59:59.000Z

    Chapters are presented concerning energy from nuclear fission; nuclear reactions and radiations; diffusion and slowing-down of neutrons; principles of reactor analysis; nuclear reactor kinetics and control; energy removal; non-fuel reactor materials; the reactor fuel system; radiation protection and environmental effects; nuclear reactor shielding; nuclear reactor safety; and power reactor systems.

  13. Light nuclei production in heavy ion collisions

    E-Print Network [OSTI]

    K. H. Khan; M. K. Suleymanov; Z. Wazir; E. U. Khan; Mahnaz Q. Haseeb; M. Ajaz

    2009-04-14T23:59:59.000Z

    Light nuclei production as a result of nuclear coalescence effect can give some signals on final state of Quark Gluon Plasma formation. We are studying the behavior of nuclear modification factor as a function of different variables using the simulated data coming from the FASTMC generator. This data is necessary to extract information on coalescence mechanism from experimental data on high energy nuclear-nuclear interactions.

  14. Nuclear Physics A 757 (2005) 127 Quarkgluon plasma and color glass condensate at

    E-Print Network [OSTI]

    Nuclear Physics A 757 (2005) 1­27 Quark­gluon plasma and color glass condensate at RHIC hadronic and partonic matter produced in ultrarelativistic heavy ion collisions at RHIC. A particular focus, the so-called quark­gluon plasma (QGP). We also discuss evidence for a possible precursor state

  15. Length control of microtubules by depolymerizing motor proteins

    E-Print Network [OSTI]

    Bindu S. Govindan; Manoj Gopalakrishnan; Debashish Chowdhury

    2008-07-08T23:59:59.000Z

    In many intracellular processes, the length distribution of microtubules is controlled by depolymerizing motor proteins. Experiments have shown that, following non-specific binding to the surface of a microtubule, depolymerizers are transported to the microtubule tip(s) by diffusion or directed walk and, then, depolymerize the microtubule from the tip(s) after accumulating there. We develop a quantitative model to study the depolymerizing action of such a generic motor protein, and its possible effects on the length distribution of microtubules. We show that, when the motor protein concentration in solution exceeds a critical value, a steady state is reached where the length distribution is, in general, non-monotonic with a single peak. However, for highly processive motors and large motor densities, this distribution effectively becomes an exponential decay. Our findings suggest that such motor proteins may be selectively used by the cell to ensure precise control of MT lengths. The model is also used to analyze experimental observations of motor-induced depolymerization.

  16. Performing local similarity searches with variable length seeds

    E-Print Network [OSTI]

    Csürös, Miklós

    Performing local similarity searches with variable length seeds Mikl´os Csur¨os D´epartement d manner. The algorithm uses a single parameter to control the speed of the similarity search there are many inventions that improve the speed of a full sensitivity search (e.g., [3]), a full-scale search

  17. Reinforcement Learning for Active Length Control of Shape Memory Alloys

    E-Print Network [OSTI]

    Valasek, John

    Reinforcement Learning for Active Length Control of Shape Memory Alloys Kenton Kirkpatrick John Valasek Aerospace Engineering Department Texas A&M University AIAA GNC Conference 21 August 2008 Honolulu;Kirkpatrick & Valasek - 5 Shape Memory Alloys (SMA) Metallic Alloys used as actuators Shape Memory Effect

  18. Multi-length Scale Modeling of CVD of Diamond Films

    E-Print Network [OSTI]

    Grujicic, Mica

    ) of single-- crystalline and polycrystalline diamond films in acrystalline and polycrystalline diamond filmsMulti-length Scale Modeling of CVD of Diamond Films M. Grujicic and S. G. LaiM. Grujicic and S. G-scale Modeling of CVD Deposition of Diamond Films RotatingRotating--disk Hotdisk Hot--filament CVD

  19. On Postnikov's Hook Length Formula for Binary Trees

    E-Print Network [OSTI]

    Chen, Bill

    note that Seo [7] also found combinatorial proof of the identity (1). Further studies related to Postnikov's hook length formula (1) have been carried out by Du and Liu [1], Gessel and Seo [2], Liu [4., 28 (2007), 1312-1321. [2] I. M. Gessel and S. Seo, A refinement of Cayley's formula for trees

  20. Long-length contaminated equipment burial containers fabrication process procedures

    SciTech Connect (OSTI)

    McCormick, W.A., Fluor Daniel Hanford

    1997-03-11T23:59:59.000Z

    These special process procedures cover the detailed step-by-step procedures required by the supplier who will manufacture the Long-Length Contaminated Equipment (LLCE) Burial Container design. Also included are detailed step-by-step procedures required by the disposal process for completion of the LLCE Burial Containers at Hanford.

  1. Corrigendum to “Suppression of ? production in d+Au and Au+Au collisions at ? SNN = 200 GeV" [Phys. Lett. B 735 (2014) 127-137

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

    Adamczyk, L. [AGH Univ. of Science and Technology, Cracow (Poland)

    2015-04-01T23:59:59.000Z

    We report measurements of ? meson production in p + p, d + Au, and Au+Au collisions using the STAR detector at RHIC. We compare the ? yield to the measured cross section in p + p collisions in order to quantify any modifications of the yield in cold nuclear matter using d + Au data and in hot nuclear matter using Au+Au data separated into three centrality classes. Our p + p measurement is based on three times the statistics of our previous result. We obtain a nuclear modification factor for Upsilon (1S + 2S + 3S) in the rapidity range |y| dAu = 0.79 ± 0.24(stat.) ± 0.03(syst.) ± 0.10(p + p syst.). A comparison with models including shadowing and initial state parton energy loss indicates the presence of additional cold-nuclear matter suppression. Similarly, in the top 10% most-central Au + Au collisions, we measure a nuclear modification factor of R AA = 0.49 ±0.1(stat.) ±0.02(syst.) ±0.06(p + p syst.), which is a larger suppression factor than that seen in cold nuclear matter. Our results are consistent with complete suppression of excited-state Upsilon mesons in Au + Au collisions. The additional suppression in Au + Au is consistent with the level expected in model calculations that include the presence of a hot, deconfined Quark–Gluon Plasma. However, understanding the suppression seen in d + Au is still needed before any definitive statements about the nature of the suppression in Au + Au can be made.

  2. Corrigendum to “Suppression of ? production in d+Au and Au+Au collisions at ? SNN = 200 GeV" [Phys. Lett. B 735 (2014) 127-137

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

    Adamczyk, L.

    2015-04-01T23:59:59.000Z

    We report measurements of ? meson production in p + p, d + Au, and Au+Au collisions using the STAR detector at RHIC. We compare the ? yield to the measured cross section in p + p collisions in order to quantify any modifications of the yield in cold nuclear matter using d + Au data and in hot nuclear matter using Au+Au data separated into three centrality classes. Our p + p measurement is based on three times the statistics of our previous result. We obtain a nuclear modification factor for Upsilon (1S + 2S + 3S) in themore »rapidity range |y| dAu = 0.79 ± 0.24(stat.) ± 0.03(syst.) ± 0.10(p + p syst.). A comparison with models including shadowing and initial state parton energy loss indicates the presence of additional cold-nuclear matter suppression. Similarly, in the top 10% most-central Au + Au collisions, we measure a nuclear modification factor of R AA = 0.49 ±0.1(stat.) ±0.02(syst.) ±0.06(p + p syst.), which is a larger suppression factor than that seen in cold nuclear matter. Our results are consistent with complete suppression of excited-state Upsilon mesons in Au + Au collisions. The additional suppression in Au + Au is consistent with the level expected in model calculations that include the presence of a hot, deconfined Quark–Gluon Plasma. However, understanding the suppression seen in d + Au is still needed before any definitive statements about the nature of the suppression in Au + Au can be made.« less

  3. Eccentricity distributions in nucleus-nucleus collisions

    E-Print Network [OSTI]

    Li Yan; Jean-Yves Ollitrault; Arthur M. Poskanzer

    2014-09-03T23:59:59.000Z

    We propose a new parametrization of the distribution of the initial eccentricity in a nucleus-nucleus collision at a fixed centrality, which we name the Elliptic Power distribution. It is a two-parameter distribution, where one of the parameters corresponds to the intrinsic eccentricity, while the other parameter controls the magnitude of eccentricity fluctuations. Unlike the previously used Bessel- Gaussian distribution, which becomes worse for more peripheral collisions, the new Elliptic Power distribution fits several Monte Carlo models of the initial state for all centralities.

  4. Full Jet Reconstruction in Heavy Ion Collisions

    E-Print Network [OSTI]

    Sevil Salur

    2009-09-16T23:59:59.000Z

    Full jet reconstruction has traditionally been thought to be difficult in heavy ion events due to large multiplicity backgrounds. The search for new physics in high luminosity p+p collisions at the LHC similarly requires the precise measurement of jets over large backgrounds caused by pile up; this has motivated the development of a new generation of jet reconstruction algorithms which are also applicable in the heavy ion environment. We review the latest results on jet-medium interactions as seen in A+A collisions at RHIC, focusing on the new techniques for full jet reconstruction.

  5. On jet structure in heavy ion collisions

    E-Print Network [OSTI]

    I. P. Lokhtin; A. A. Alkin; A. M. Snigirev

    2015-04-19T23:59:59.000Z

    The LHC data on jet fragmentation function and jet shapes in PbPb collisions at center-of-mass energy 2.76 TeV per nucleon pair are analyzed and interpreted in the frameworks of PYQUEN jet quenching model. A specific modification of longitudinal and radial jet profiles in most central PbPb collisions as compared with pp data is close to that obtained with PYQUEN simulations taking into account wide-angle radiative and collisional partonic energy loss. The contribution of radiative and collisional loss to the medium-modified intra-jet structure is estimated.

  6. www.physicstoday.org November 2012 Physics Today 59 Nuclear energy can provide great

    E-Print Network [OSTI]

    www.physicstoday.org November 2012 Physics Today 59 Nuclear energy can provide great The Nuclear on keeping costs and book length in check. For example, most of the graphics use gray- scale, with only a few pages in the cen- ter providing color plates. In addition, in many places additional graphics could have

  7. Evaluation of the relationship between fracture conductivity, fracture fluid production, and effective fracture length

    E-Print Network [OSTI]

    Lolon, Elyezer P.

    2006-04-12T23:59:59.000Z

    Low-permeability gas wells often produce less than predicted after a fracture treatment. One of the reasons for this is that fracture lengths calculated after stimulation are often less than designed lengths. While actual fracture lengths may...

  8. Evaluation of the relationship between fracture conductivity, fracture fluid production, and effective fracture length 

    E-Print Network [OSTI]

    Lolon, Elyezer P.

    2006-04-12T23:59:59.000Z

    Low-permeability gas wells often produce less than predicted after a fracture treatment. One of the reasons for this is that fracture lengths calculated after stimulation are often less than designed lengths. While actual fracture lengths may...

  9. Association of length-slow silica with evaporites

    SciTech Connect (OSTI)

    Heaney, P.J. (Princeton Univ., Princeton, NJ (United States). Dept. of Geology); Sheppard, R.A. (Geological Survey, Denver, CO (United States). Denver Federal Center); Post, J.E. (Smithsonian Inst., Washington, DC (United States). Dept. of Mineral Sciences)

    1992-01-01T23:59:59.000Z

    In 1971, Folk and Pittman described the common occurrence of length-slow quartz (or lutecite) with evaporitic minerals, and they suggested that lutecite might be a useful indicator for vanished evaporites. However, the subsequent discoveries of length-slow silica in carbonate turbidites and in abyssal Pacific cherts revealed that lutecite is not restricted to near-surface deposits. Moreover, Kastner found that length-slow quartz could be crystallized in slightly alkaline solutions enriched in Mg[sup 2+], Na[sup +], and SO[sub 4][sup [minus]2]. Following these studies, researchers have cited the presence of lutecite in rock samples as suggestive but not compelling evidence for an evaporitic origin, and the precise nature of this form of silica has remained somewhat enigmatic. Investigations of chert nodules from evaporitic and non-evaporitic regimes support an identification of length-slow quartz'' with the mineral moganite, a polymorph of silica that is fibrous and optically length slow. Results are based upon X-ray powder diffraction of the chert, followed by Rietveld refinement of the X-ray patterns to quantify the weight fraction of quartz and moganite in each specimen. Most non-evaporitic chert appears to contain between 5 and 15 wt. % moganite, but evaporitic cherts often contain more than 20 wt. %. Cherts that have transformed from precursor magadiite can be particularly rich in moganite; samples from Lake Magadi, Kenya and from Harney Lake, Oregon revealed about equal parts moganite and quartz. However, the observation of decreasing abundances of moganite in rocks of increasing age indicates that moganite is metastable relative to quartz.

  10. NUCLEAR DEFORMATION ENERGIES

    E-Print Network [OSTI]

    Blocki, J.

    2009-01-01T23:59:59.000Z

    J.R. Nix, Theory of Nuclear Fission and Superheavy Nuclei,energy maps relevant for nuclear fission and nucleus-nucleusin connection with nuclear fission. The need for a better

  11. Office of Nuclear Safety

    Broader source: Energy.gov [DOE]

    The Office of Nuclear Safety establishes nuclear safety requirements and expectations for the Department to ensure protection of workers and the public from the hazards associated with nuclear operations with all Department operations.

  12. Nuclear Explosive Safety

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2015-01-26T23:59:59.000Z

    This Department of Energy (DOE) Order establishes requirements to implement the nuclear explosive safety (NES) elements of DOE O 452.1E, Nuclear Explosive and Weapon Surety Program, or successor directive, for routine and planned nuclear explosive operations (NEOs).

  13. Nuclear Explosive Safety

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2014-07-10T23:59:59.000Z

    The Order establishes requirements to implement the nuclear explosive safety (NES) elements of DOE O 452.1E, Nuclear Explosive and Weapon Surety Program, for routine and planned nuclear explosive operations (NEOs).

  14. NUCLEAR STRUCTURE DATABASE

    E-Print Network [OSTI]

    Firestone, R.B.

    2010-01-01T23:59:59.000Z

    CALIFORNIA NUCLEAR STRUCTURE DATABASE R. B. Firestone and E.11089 NUCLEAR STRUCTURE DATABASE by R.B. Firestone and E.iii- NUCLEAR STRUCTURE DATABASE R.B Firestone and E. Browne

  15. Nuclear Safety (Pennsylvania)

    Broader source: Energy.gov [DOE]

    The Nuclear Safety Division conducts a comprehensive nuclear power plant oversight review program of the nine reactors at the five nuclear power sites in Pennsylvania. It also monitors the...

  16. Nuclear Fuel Cycle & Vulnerabilities

    SciTech Connect (OSTI)

    Boyer, Brian D. [Los Alamos National Laboratory

    2012-06-18T23:59:59.000Z

    The objective of safeguards is the timely detection of diversion of significant quantities of nuclear material from peaceful nuclear activities to the manufacture of nuclear weapons or of other nuclear explosive devices or for purposes unknown, and deterrence of such diversion by the risk of early detection. The safeguards system should be designed to provide credible assurances that there has been no diversion of declared nuclear material and no undeclared nuclear material and activities.

  17. Inequalities for low-energy symmetric nuclear matter

    E-Print Network [OSTI]

    Dean Lee

    2004-07-24T23:59:59.000Z

    Using effective field theory we prove inequalities for the correlations of two-nucleon operators in low-energy symmetric nuclear matter. For physical values of operator coefficients in the effective Lagrangian, the S = 1, I = 0 channel correlations must have the lowest energy and longest correlation length in the two-nucleon sector. This result is valid at nonzero density and temperature.

  18. Nuclear Physics: Campaigns

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

    Free-Electron Laser (FEL) Medical Imaging Physics Topics Campaigns The Structure of the Nuclear Building Blocks The Structure of Nuclei Symmetry Tests in Nuclear Physics Meetings...

  19. Nuclear Power Overview

    Broader source: Energy.gov (indexed) [DOE]

    San Onofre Nuclear Generating Station San Onofre Nuclear Generating Station Bob Ashe-Everest Southern California Edison 10 Incoming New Fuel Inspecting New Fuel SONGS Unit 1 Fuel...

  20. Nuclear weapons modernizations

    SciTech Connect (OSTI)

    Kristensen, Hans M. [Federation of American Scientists, Washington, DC (United States)

    2014-05-09T23:59:59.000Z

    This article reviews the nuclear weapons modernization programs underway in the world's nine nuclear weapons states. It concludes that despite significant reductions in overall weapons inventories since the end of the Cold War, the pace of reductions is slowing - four of the nuclear weapons states are even increasing their arsenals, and all the nuclear weapons states are busy modernizing their remaining arsenals in what appears to be a dynamic and counterproductive nuclear competition. The author questions whether perpetual modernization combined with no specific plan for the elimination of nuclear weapons is consistent with the nuclear Non-Proliferation Treaty and concludes that new limits on nuclear modernizations are needed.

  1. Advancing Global Nuclear Security

    Broader source: Energy.gov [DOE]

    Today world leaders gathered at The Hague for the Nuclear Security Summit, a meeting to measure progress and take action to secure sensitive nuclear materials.

  2. Initialization of hydrodynamics in relativistic heavy ion collisions with an energy-momentum transport model

    E-Print Network [OSTI]

    V. Yu. Naboka; S. V. Akkelin; Iu. A. Karpenko; Yu. M. Sinyukov

    2015-01-14T23:59:59.000Z

    A key ingredient of hydrodynamical modeling of relativistic heavy ion collisions is thermal initial conditions, an input that is the consequence of a pre-thermal dynamics which is not completely understood yet. In the paper we employ a recently developed energy-momentum transport model of the pre-thermal stage to study influence of the alternative initial states in nucleus-nucleus collisions on flow and energy density distributions of the matter at the starting time of hydrodynamics. In particular, the dependence of the results on isotropic and anisotropic initial states is analyzed. It is found that at the thermalization time the transverse flow is larger and the maximal energy density is higher for the longitudinally squeezed initial momentum distributions. The results are also sensitive to the relaxation time parameter, equation of state at the thermalization time, and transverse profile of initial energy density distribution: Gaussian approximation, Glauber Monte Carlo profiles, etc. Also, test results ensure that the numerical code based on the energy-momentum transport model is capable of providing both averaged and fluctuating initial conditions for the hydrodynamic simulations of relativistic nuclear collisions.

  3. Alternative Scenarios of Relativistic Heavy-Ion Collisions: I. Baryon Stopping

    E-Print Network [OSTI]

    Yu. B. Ivanov

    2013-02-23T23:59:59.000Z

    Simulations of relativistic heavy-ion collisions within the three-fluid model employing a purely hadronic equation of state (EoS) and two versions of the EoS involving deconfinement transition are presented. The latter are an EoS with the first-order phase transition and that with a smooth crossover transition. The model setup is described in detail. The analysis is performed in a wide range of incident energies 2.7 GeV $< \\sqrt{s_{NN}} <$ 39 GeV in terms of the center-of-mass energy. Results on proton and net-proton rapidity distributions are reported. Comparison with available data indicate certain preference of the crossover EoS. It is found that predictions within deconfinement-transition scenarios exhibit a "peak-dip-peak-dip" irregularity in the incident energy dependence of the form of the net-proton rapidity distributions in central collisions. This irregularity is a signal of deconfinement onset occurring in the hot and dense stage of the nuclear collision.

  4. Nuclear / Radiological Advisory Team | National Nuclear Security...

    National Nuclear Security Administration (NNSA)

    Radiological Advisory Team | National Nuclear Security Administration Facebook Twitter Youtube Flickr RSS People Mission Managing the Stockpile Preventing Proliferation Powering...

  5. Nuclear Security Summit | National Nuclear Security Administration

    National Nuclear Security Administration (NNSA)

    Twitter Youtube Flickr RSS People Mission Managing the Stockpile Preventing Proliferation Powering the Nuclear Navy Emergency Response Recapitalizing Our Infrastructure...

  6. Nuclear Safeguards | National Nuclear Security Administration

    National Nuclear Security Administration (NNSA)

    Twitter Youtube Flickr RSS People Mission Managing the Stockpile Preventing Proliferation Powering the Nuclear Navy Emergency Response Recapitalizing Our Infrastructure...

  7. Studies of multiplicity in relativistic heavy-ion collisions

    E-Print Network [OSTI]

    B. B. Back

    2004-11-29T23:59:59.000Z

    In this talk I'll review the present status of charged particle multiplicity measurements from heavy-ion collisions. The characteristic features of multiplicity distributions obtained in Au+Au collisions will be discussed in terms of collision centrality and energy and compared to those of p+p collisions. Multiplicity measurements of d+Au collisions at 200 GeV nucleon-nucleon center-of-mass energy will also be discussed. The results will be compared to various theoretical models and simple scaling properties of the data will be identified.

  8. J/$?$ and $?$(2S) production in p-Pb collisions with ALICE at the LHC

    E-Print Network [OSTI]

    Marco Leoncino; for the ALICE collaboration

    2014-10-09T23:59:59.000Z

    The ALICE collaboration has studied the inclusive J/$\\psi$ and $\\psi(\\mathrm{2S})$ production in p-Pb collisions at $\\sqrt{s_{NN}}$ = 5.02 TeV at the CERN LHC. The J/$\\psi$ measurement is performed in the $\\mu^{+}\\mu^{-}$ ( - 4.46 agreement with theoretical predictions based on nuclear shadowing, as well as with models including, in addition, a contribution from partonic energy loss. Finally, the $\\psi(\\mathrm{2S})$ measurement in the $\\mu^{+}\\mu^{-}$ decay channel has been performed. In particular, a significantly smaller $\\psi(\\mathrm{2S})$ nuclear modification factor, with respect to the J$/\\psi$ one, has been observed.

  9. $J/?$ suppression in Pb+Pb collisions and $p_T$ broadening

    E-Print Network [OSTI]

    A. K. Chaudhuri

    2003-04-10T23:59:59.000Z

    We have analysed the NA50 data, on the centrality dependence of $p_T$ broadening of $J/\\psi$'s, in Pb+Pb collisions, at the CERN-SPS. The data were analysed in a QCD based model, where $J/\\psi$'s are suppressed in 'nuclear' medium. Without any free parameter, the model could explain the NA50 $p_T$ broadening data. The data were also analysed in a QGP based threshold model, where $J/\\psi$ suppression is 100% above a critical density. The QGP based model could not explain the NA50 $p_T$ broadening data. We have also predicted the centrality dependence of $J/\\psi$ suppression and $p_T$ broadening at RHIC energy. Both the models, the QGP based threshold model and the QCD based nuclear absorption model, predict $p_T$ broadening very close to each other.

  10. The quarkonium saga in heavy ion collisions

    E-Print Network [OSTI]

    Tserruya, Itzhak

    2013-01-01T23:59:59.000Z

    J/psi suppression was proposed more than 25 years ago as an unambiguous signature for the formation of the Quark Gluon Plasma in relativistic heavy ion collisions. After intensive efforts, both experimental and theoretical, the quarkonium saga remains exciting, producing surprising results and not fully understood. This talk focuses on recent results on quarkonium production at RHIC and the LHC.

  11. Sufficient Conditions for Collision-Resistant Hashing

    E-Print Network [OSTI]

    Ostrovsky, Rafail

    information retrieval (PIR) protocols and homomorphic one-way commitments. Keywords. Collision-resistant hash. A homomorphic encryption is a semantically secure encryption in which the plaintexts are taken from a group (single-server, sublinear-communication) one-round PIR protocol [15]. Since PIR is implied by homomorphic

  12. High energy photon-photon collisions

    SciTech Connect (OSTI)

    Brodsky, S.J. [Stanford Linear Accelerator Center, Menlo Park, CA (United States); Zerwas, P.M. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    1994-07-01T23:59:59.000Z

    The collisions of high energy photons produced at a electron-positron collider provide a comprehensive laboratory for testing QCD, electroweak interactions and extensions of the standard model. The luminosity and energy of the colliding photons produced by back-scattering laser beams is expected to be comparable to that of the primary e{sup +}e{sup {minus}} collisions. In this overview, we shall focus on tests of electroweak theory in photon-photon annihilation, particularly {gamma}{gamma} {yields} W{sup +}W{sup {minus}}, {gamma}{gamma} {yields} Higgs bosons, and higher-order loop processes, such as {gamma}{gamma} {yields} {gamma}{gamma}, Z{gamma} and ZZ. Since each photon can be resolved into a W{sup +}W{sup minus} pair, high energy photon-photon collisions can also provide a remarkably background-free laboratory for studying WW collisions and annihilation. We also review high energy {gamma}{gamma} tests of quantum chromodynamics, such as the scaling of the photon structure function, t{bar t} production, mini-jet processes, and diffractive reactions.

  13. Experience with Offset Collisions in the LHC

    E-Print Network [OSTI]

    Papotti, G; Calaga, R; Follin, F; Giachino, R; Herr, W; Miyamoto, R; Pieloni, T; Schaumann, M

    2011-01-01T23:59:59.000Z

    To keep the luminosity under control, some experiments require the adjustment of the luminosity during a fill, socalled luminosity levelling. One option is the separate the beams transversely and adjust the separation to the desired collision rate. The results from controlled experiments are reported and interpreted. The feasibility of this method for ultimate luminosities is discussed.

  14. PROMPT PHOTON PRODUCTION IN POLARIZED HADRON COLLISIONS.

    SciTech Connect (OSTI)

    VOGELSANG,W.

    2000-04-25T23:59:59.000Z

    We consider spin asymmetries for prompt photon production in collisions of longitudinally polarized hadrons. This reaction will be a key tool at the BNL-RHIC {rvec p}{rvec p} collider for determining the gluon spin density in a polarized proton. We study the effects of QCD corrections, such as all-order soft-gluon ''threshold'' resummations.

  15. Collision Avoidance in Depth Space I. INTRODUCTION

    E-Print Network [OSTI]

    De Luca, Alessandro

    ; compute distances between the obstacles and the robot; optionally project the results in the CartesianCollision Avoidance in Depth Space I. INTRODUCTION When humans and robots share the same work space, safety is the primary issue of concern [8]. Secondary but not negligible is to prevent robot damages due

  16. Causal dissipative hydrodynamics for heavy ion collisions

    E-Print Network [OSTI]

    Chaudhuri, A K

    2011-01-01T23:59:59.000Z

    We briefly discuss the recent developments in causal dissipative hydrodynamic for relativistic heavy ion collisions. Phenomenological estimate of QGP viscosity over entropy ratio from several experimental data, e.g. STAR's $\\phi$ meson data, centrality dependence of elliptic flow, universal scaling elliptic flow etc. are discussed. QGP viscosity, extracted from hydrodynamical model analysis can have very large systematic uncertainty due to uncertain initial conditions.

  17. Causal dissipative hydrodynamics for heavy ion collisions

    E-Print Network [OSTI]

    A. K. Chaudhuri

    2011-01-23T23:59:59.000Z

    We briefly discuss the recent developments in causal dissipative hydrodynamic for relativistic heavy ion collisions. Phenomenological estimate of QGP viscosity over entropy ratio from several experimental data, e.g. STAR's $\\phi$ meson data, centrality dependence of elliptic flow, universal scaling elliptic flow etc. are discussed. QGP viscosity, extracted from hydrodynamical model analysis can have very large systematic uncertainty due to uncertain initial conditions.

  18. High energy hadron-hadron collisions

    SciTech Connect (OSTI)

    Chou, T.T.

    1991-12-01T23:59:59.000Z

    Results of a study on high energy collision with the geometrical model are summarized in three parts: (1) the elastic hadron-hadron collision, (2) the inelastic hadron-hadron collision, and (3) the e{sup +}e{sup {minus}} annihilation. More recent studies are highlighted below. For elastic scattering, a modified form for the hadronic matter form factor of the proton was proposed which remains to be dipole in form but contains an energy-dependent range parameter. This new expression of the opacity function fits the elastic {bar p}p scattering very well from the ISR to S{bar p}pS energies. Extrapolation of this theory also yielded results in good agreement with the {bar p}p differential cross section measured at the Tevatron. For inelastic hadron-hadron collisions, we have made a systematic investigation of the single-particle momentum spectra in the entire S{bar p}pS energy region. Results are useful for the extrapolation of angular distribution to the higher SSC energies. In e{sup +}e{sup {minus}} annihilation, a detailed analysis of all available experimental multiplicity data from PETRA to LEP energies has been performed. We discovered that the cluster size of emitted hadrons increases steadily with energy and is close to 2 as we predicted.

  19. Grazing collisions of gravitational shock waves and entropy production in heavy ion collisions

    SciTech Connect (OSTI)

    Lin Shu; Shuryak, Edward [Department of Physics and Astronomy, SUNY, Stony Brook, New York 11794 (United States)

    2009-06-15T23:59:59.000Z

    AdS/CFT correspondence is now widely used for the study of strongly coupled plasmas, such as those produced in ultrarelativistic heavy ion collisions at the Relativistic Heavy Ion Collider. While properties of equilibrated plasma and small deviations from equilibrium are by now reasonably well understood, the plasma's initial formation and thermal equilibration is a much more challenging issue which remains to be studied. In the dual gravity language, these problems are related to the formation of bulk black holes, and studying trapped surfaces, as we do in this work, is a way to estimate the properties (temperature and entropy) of such black holes. Extending the work by Gubser et al. for central collisions, we find numerically trapped surfaces for noncentral collisions of ultrarelativistic black holes (gravitational shock waves) with different energies. We observe that beyond a certain critical impact parameter, the trapped surface does not exist, and we argue that there are some experimental indications for a similar jump in entropy production as a function of the impact parameter in real heavy ion collisions. We also present a simple solvable example of the so-called wall-on-wall collision, for colliding objects that depend on the holographic coordinate only. Finally, we critically discuss the applicability of the AdS/CFT approach to real-world heavy ion collisions.

  20. The Joys of Nuclear Engineering

    SciTech Connect (OSTI)

    Jon Carmack

    2009-10-02T23:59:59.000Z

    Nuclear fuels researcher Jon Carmack talks about the satisfactions of a career in nuclear engineering.

  1. The Joys of Nuclear Engineering

    ScienceCinema (OSTI)

    Jon Carmack

    2010-01-08T23:59:59.000Z

    Nuclear fuels researcher Jon Carmack talks about the satisfactions of a career in nuclear engineering.

  2. Dangerous implications of a minimum length in quantum gravity

    E-Print Network [OSTI]

    Cosimo Bambi; Katherine Freese

    2008-07-17T23:59:59.000Z

    The existence of a minimum length and a generalization of the Heisenberg uncertainty principle seem to be two fundamental ingredients required in any consistent theory of quantum gravity. In this letter we show that they would predict dangerous processes which are phenomenologically unacceptable. For example, long--lived virtual super--Planck mass black holes may lead to rapid proton decay. Possible solutions of this puzzle are briefly discussed.

  3. Critical Waves and the Length Problem of Biology

    E-Print Network [OSTI]

    R. B. Laughlin

    2015-04-17T23:59:59.000Z

    It is pointed out that the mystery of how biological systems measure their lengths vanishes away if one premises that they have discovered a way to generate linear waves analogous to compressional sound. These can be used to detect length at either large or small scales using echo timing and fringe counting. It is shown that suitable linear chemical potential waves can, in fact, be manufactured by tuning to criticality conventional reaction-diffusion with a small number substances. Min oscillations in E. coli are cited as precedent resonant length measurement using chemical potential waves analogous to laser detection. Mitotic structures in eucaryotes are identified as candidates for such an effect at higher frequency. The engineering principle is shown to be very general and functionally the same as that used by hearing organs. PNAS Significance Statement: This paper invokes physical principles to address the question of how living things might use reaction-diffusion to measure out and regulate the many thousands of lengths required to make their body parts and internal organs. It argues that two ideas have been missing. One is that oscillation is necessary to achieve the necessary design stability and plasticity. The other is that the system must be tuned to criticality to stabilize the propagation velocity, thus enabling clocks to function as meter sticks. The broader significance is twofold: First, a fundamental piece of the machinery of life is probably invisible to present-day biochemical methods because they are too slow. Second, the simplicity of growth and form identified a century ago by D'Arcy Thompson is probably a symptom of biological engineering strategies, not primitive law.

  4. Multi-length Scale Modeling of Titanium Nitride Coatings

    E-Print Network [OSTI]

    Grujicic, Mica

    Multi-length Scale Modeling of Titanium Nitride Coatings M. Grujicic and S. G. LaiM. Grujicic and S Conservation Circumferential Momentum Conservation Thermal Energy Balance Species Continuity Dependent of Titanium Nitride Surface Species TiCl4(S): NH2(S): TiCl2(S): NH(S): TiCl(S): N(S): Ti (S): N*(S): Ti*(S): N

  5. Magnetic field-line lengths inside interplanetary magnetic flux ropes

    E-Print Network [OSTI]

    Hu, Qiang; Krucker, Sam

    2015-01-01T23:59:59.000Z

    We report on the detailed and systematic study of field-line twist and length distributions within magnetic flux ropes embedded in Interplanetary Coronal Mass Ejections (ICMEs). The Grad-Shafranov reconstruction method is utilized together with a constant-twist nonlinear force-free (Gold-Hoyle) flux rope model to reveal the close relation between the field-line twist and length in cylindrical flux ropes, based on in-situ Wind spacecraft measurements. We show that the field-line twist distributions within interplanetary flux ropes are inconsistent with the Lundquist model. In particular we utilize the unique measurements of magnetic field-line lengths within selected ICME events as provided by Kahler et al. (2011) based on energetic electron burst observations at 1 AU and the associated type III radio emissions detected by the Wind spacecraft. These direct measurements are compared with our model calculations to help assess the flux-rope interpretation of the embedded magnetic structures. By using the differen...

  6. ANNOUNCEMENT NUCLEAR ENGINEERING FACULTY POSITION

    E-Print Network [OSTI]

    Tennessee, University of

    ANNOUNCEMENT NUCLEAR ENGINEERING FACULTY POSITION The Department of Nuclear Engineering at the Assistant or Associate Professor level. These areas include, but are not limited to, nuclear system instrumentation & controls, monitoring and diagnostics, reactor dynamics, nuclear security, nuclear materials

  7. Leading twist nuclear shadowing phenomena in hard processes with nuclei

    SciTech Connect (OSTI)

    Leonid Frankfurt, Vadim Guzey, Mark Strikman

    2012-03-01T23:59:59.000Z

    We present and discuss the theory and phenomenology of the leading twist theory of nuclear shadowing which is based on the combination of the generalization of Gribov-Glauber theory, QCD factorization theorems, and HERA QCD analysis of diffraction in lepton-proton deep inelastic scattering (DIS). We apply this technique for the analysis of a wide range of hard processes with nuclei-inclusive DIS on deuterons, medium-range and heavy nuclei, coherent and incoherent diffractive DIS with nuclei, and hard diffraction in proton-nucleus scattering - and make predictions for the effect of nuclear shadowing in the corresponding sea quark and gluon parton distributions. We also analyze the role of the leading twist nuclear shadowing in generalized parton distributions in nuclei and certain characteristics of final states in nuclear DIS. We discuss the limits of applicability of the leading twist approximation for small x scattering off nuclei and the onset of the black disk regime and methods of detecting it. It will be possible to check many of our predictions in the near future in the studies of the ultraperipheral collisions at the Large Hadron Collider (LHC). Further checks will be possible in pA collisions at the LHC and forward hadron production at Relativistic Heavy Ion Collider (RHIC). Detailed tests will be possible at an Electon-Ion Collider (EIC) in USA and at the Large Hadron-Electron Collider (LHeC) at CERN.

  8. Collision lifetimes of polyatomic molecules at low temperatures: Benzene–benzene vs benzene–rare gas atom collisions

    SciTech Connect (OSTI)

    Cui, Jie; Krems, Roman V. [Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1 (Canada); Li, Zhiying [Department of Physics, Harvard University, Cambridge, Massachusetts 02138 (United States)

    2014-10-28T23:59:59.000Z

    We use classical trajectory calculations to study the effects of the interaction strength and the geometry of rigid polyatomic molecules on the formation of long-lived collision complexes at low collision energies. We first compare the results of the calculations for collisions of benzene molecules with rare gas atoms He, Ne, Ar, Kr, and Xe. The comparison illustrates that the mean lifetimes of the collision complexes increase monotonically with the strength of the atom–molecule interaction. We then compare the results of the atom–benzene calculations with those for benzene–benzene collisions. The comparison illustrates that the mean lifetimes of the benzene–benzene collision complexes are significantly reduced due to non-ergodic effects prohibiting the molecules from sampling the entire configuration space. We find that the thermally averaged lifetimes of the benzene–benzene collisions are much shorter than those for Xe with benzene and similar to those for Ne with benzene.

  9. Nuclear-deformation energies according to a liquid-drop model with a sharp surface

    SciTech Connect (OSTI)

    Blocki, J.; Swiatecki, W.J.

    1982-05-01T23:59:59.000Z

    We present an atlas of 665 deformation-energy maps and 150 maps of other properties of interest, relevant for nuclear systems idealized as uniformly charged drops endowed with a surface tension. The nuclear shapes are parametrized in terms of two spheres modified by a smoothly fitted quadratic surface of revolution and are specified by three variables: asymmetry, sphere separation, and a neck variable (that goes over into a fragment-deformation variable after scission). The maps and related tables should be useful for the study of macroscopic aspects of nuclear fission and of collisions between any two nuclei in the periodic table.

  10. Study Medium-induced Parton Energy Loss in Gamma+jet Events of High-Energy Heavy-Ion Collisions

    E-Print Network [OSTI]

    Xin-Nian Wang; Zheng Huang

    1997-01-09T23:59:59.000Z

    The effect of medium-induced parton energy loss on jet fragmentation is studied in high-energy heavy-ion collisions. It is shown that an effective jet fragmentation function can be extracted from the inclusive $p_T$ spectrum of charged particles in the opposite direction of a tagged direct photon with a fixed transverse energy. We study the modification of the effective jet fragmentation function due to parton energy loss in AA as compared to pp collisions, including $E_T$ smearing from initial state radiations for the photon-tagged jets. The effective fragmentation function at $z=p_T/E_T^\\gamma\\sim 1$ in pA collisions is shown to be sensitive to the additional $E_T$ smearing due to initial multiple parton scatterings whose effect must be subtracted out in AA collisions in order to extract the effective parton energy loss. Jet quenching in deeply inelastic lepton-nucleus scatterings as a measure of the parton energy loss in cold nuclear matter is also discussed. We also comment on the experimental feasibilities of the proposed study at the RHIC and LHC energies and some alternative measurements such as using $Z^0$ as a tag at the LHC energy.

  11. Hadronic resonance production in $d$+Au collisions at $\\sqrt{s_{_{NN}}}$ = 200 GeV at RHIC

    E-Print Network [OSTI]

    B. I. Abelev

    2008-08-22T23:59:59.000Z

    We present the first measurements of the $\\rho(770)^0$, $K^*$(892), $\\Delta$(1232)$^{++}$, $\\Sigma$(1385), and $\\Lambda$(1520) resonances in $d$+Au collisions at $\\sqrt{s_{_{NN}}}$ = 200 GeV, reconstructed via their hadronic decay channels using the STAR detector at RHIC. 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 ($m_T$). The $$ of resonances in minimum bias collisions is compared to the $$ of $\\pi$, $K$, and $\\bar{p}$. The $\\rho^0/\\pi^-$, $K^*/K^-$, $\\Delta^{++}/p$, $\\Sigma(1385)/\\Lambda$, and $\\Lambda(1520)/\\Lambda$ ratios in $d$+Au collisions are compared to the measurements in minimum bias $p+p$ interactions, where we observe that both measurements are comparable. The nuclear modification factors ($R_{dAu}$) of the $\\rho^0$, $K^*$, and $\\Sigma^*$ scale with the number of binary collisions ($N_{bin}$) for $p_T >$ 1.2 GeV/$c$.

  12. Hadronic resonance production in d + Au collisions at sqrt s NN = 200 GeV at RHIC

    SciTech Connect (OSTI)

    STAR Coll

    2008-08-22T23:59:59.000Z

    We present the first measurements of the {rho}(770){sup 0}, K*(892), {Delta}(1232){sup ++}, {Sigma}(1385), and {Lambda}(1520) resonances in d+Au collisions at {radical}s{sub NN} = 200 GeV, reconstructed via their hadronic decay channels using the STAR detector at RHIC. The masses and widths of these resonances are studied as a function of transverse momentum (p{sub T}). We observe that the resonance spectra follow a generalized scaling law with the transverse mass (m{sub T}). The of resonances in minimum bias collisions is compared to the of {pi}, K, and {bar p}. The {rho}{sup 0}/{pi}{sup -}, K*/K{sup -}, {Delta}{sup ++}/p, {Sigma}(1385)/{Lambda}, and {Lambda}(1520)/{Lambda} ratios in d + Au collisions are compared to the measurements in minimum bias p + p interactions, where we observe that both measurements are comparable. The nuclear modification factors (R{sub dAu}) of the {rho}{sup 0}, K*, and {Sigma}* scale with the number of binary collisions (N{sub bin}) for p{sub T} > 1.2 GeV/c.

  13. Advanced nuclear fuel

    SciTech Connect (OSTI)

    Terrani, Kurt

    2014-07-14T23:59:59.000Z

    Kurt Terrani uses his expertise in materials science to develop safer fuel for nuclear power plants.

  14. Nuclear Reaction Data Centers

    SciTech Connect (OSTI)

    McLane, V.; Nordborg, C.; Lemmel, H.D.; Manokhin, V.N.

    1988-01-01T23:59:59.000Z

    The cooperating Nuclear Reaction Data Centers are involved in the compilation and exchange of nuclear reaction data for incident neutrons, charged particles and photons. Individual centers may also have services in other areas, e.g., evaluated data, nuclear structure and decay data, reactor physics, nuclear safety; some of this information may also be exchanged between interested centers. 20 refs., 1 tab.

  15. Catalysinganenergyrevolution Nuclear Failures

    E-Print Network [OSTI]

    Laughlin, Robert B.

    extraction, fuel manufacture and management of spent fuel and waste. Currently, CEA is a large FrenchCatalysinganenergyrevolution France's Nuclear Failures The great illusion of nuclear energy greenpeace.org #12;Contents 2 Greenpeace International France's Nuclear Failures The French nuclear industry

  16. Advanced nuclear fuel

    ScienceCinema (OSTI)

    Terrani, Kurt

    2014-07-15T23:59:59.000Z

    Kurt Terrani uses his expertise in materials science to develop safer fuel for nuclear power plants.

  17. Focus Article Nuclear winter

    E-Print Network [OSTI]

    Robock, Alan

    the climatic effects of nuclear war. Smoke from the fires started by nuclear weapons, especially the black in recorded human history. Although the number of nuclear weapons in the world has fallen from 70,000 at its and Russia could still produce nuclear winter. This theory cannot be tested in the real world. However

  18. Elimination of influence of neutron-skin size difference of initial colliding nuclei in Pb+Pb collisions

    E-Print Network [OSTI]

    Gao-Feng Wei

    2015-01-22T23:59:59.000Z

    Within an isospin- and momentum-dependent transport model using as an input nucleon density profiles from Hartree-Fock calculations based on a modified Skyrme-like (MSL) model, we study how to eliminate the influence of neutron-skin size difference of initial colliding nuclei in probing the nuclear symmetry energy. Within the current experimental uncertainty range of neutron-skin size of $^{208}$Pb, the Pb+Pb collisions are performed in semicentral and peripheral collisions with impact parameters of 5 and 9fm and at beam energies from 50 MeV/nucleon to 1000 MeV/nucleon, respectively. It is shown that combination of neutron and proton collective flows, i.e., neutron-proton differential elliptic flow, neutron-proton elliptic flow difference, neutron-proton differential transverse flow and neutron-proton transverse flow difference, can effectively eliminate the effects of neutron-skin size difference and thus can be as useful sensitive observables in probing nuclear matter symmetry energy in heavy-ion collisions. Moreover, the combined neutron-proton stopping power including the neutron-proton differential stopping power and neutron-proton stopping power difference can also eliminate the effects of neutron-skin size difference and shows some sensitivities to symmetry energy especially at the lower beam energy.

  19. Top-quark production in proton-nucleus and nucleus-nucleus collisions at LHC energies and beyond

    E-Print Network [OSTI]

    d'Enterria, David; Paukkunen, Hannu

    2015-01-01T23:59:59.000Z

    Single and pair top-quark production in proton-lead (p-Pb) and lead-lead (Pb-Pb) collisions at the CERN Large Hadron Collider (LHC) and future circular collider (FCC) energies, are studied with next-to-leading-order perturbative QCD calculations including nuclear parton distribution functions. At the LHC, the pair-production cross sections amount to sigma(t-tbar) = 3.4 mub in Pb-Pb at sqrt(s) = 5.5 TeV, and sigma(t-tbar) = 60 nb in p-Pb at sqrt(s) = 8.8 TeV. At the FCC energies of sqrt(s) = 39 and 63 TeV, the same cross sections are factors of 90 and 55 times larger respectively. In the leptonic final-state t-tbar --> W+b W-bbar --> b bbar l+l- nu+nu-, after typical acceptance and efficiency cuts, one expects about 90 and 300 top-quarks per nominal LHC-year and 4.7 10^4 and 10^5 per FCC-year in Pb-Pb and p-Pb collisions respectively. The total t-tbar cross sections, dominated by gluon fusion processes, are enhanced by 3--8% in nuclear compared to p-p collisions due to an overall net gluon antishadowing, altho...

  20. Beam-energy and system-size dependence of the space-time extent of the pion emission source produced in heavy ion collisions

    E-Print Network [OSTI]

    A. Adare; S. Afanasiev; C. Aidala; N. N. Ajitanand; Y. Akiba; R. Akimoto; H. Al-Bataineh; H. Al-Ta'ani; J. Alexander; M. Alfred; A. Angerami; K. Aoki; N. Apadula; L. Aphecetche; Y. Aramaki; R. Armendariz; S. H. Aronson; J. Asai; H. Asano; E. C. Aschenauer; E. T. Atomssa; R. Averbeck; T. C. Awes; B. Azmoun; V. Babintsev; M. Bai; G. Baksay; L. Baksay; A. Baldisseri; N. S. Bandara; B. Bannier; K. N. Barish; P. D. Barnes; B. Bassalleck; A. T. Basye; S. Bathe; S. Batsouli; V. Baublis; C. Baumann; S. Baumgart; A. Bazilevsky; M. Beaumier; S. Beckman; S. Belikov; R. Belmont; R. Bennett; A. Berdnikov; Y. Berdnikov; A. A. Bickley; X. Bing; D. Black; D. S. Blau; J. G. Boissevain; J. S. Bok; H. Borel; K. Boyle; M. L. Brooks; J. Bryslawskyj; H. Buesching; V. Bumazhnov; G. Bunce; S. Butsyk; C. M. Camacho; S. Campbell; P. Castera; B. S. Chang; J. -L. Charvet; C. -H. Chen; S. Chernichenko; C. Y. Chi; J. Chiba; M. Chiu; I. J. Choi; J. B. Choi; S. Choi; R. K. Choudhury; P. Christiansen; T. Chujo; P. Chung; A. Churyn; O. Chvala; V. Cianciolo; Z. Citron; C. R. Cleven; B. A. Cole; M. P. Comets; M. Connors; P. Constantin; M. Csanád; T. Csörg?; T. Dahms; S. Dairaku; I. Danchev; K. Das; A. Datta; M. S. Daugherity; G. David; M. B. Deaton; K. DeBlasio; K. Dehmelt; H. Delagrange; A. Denisov; D. d'Enterria; A. Deshpande; E. J. Desmond; K. V. Dharmawardane; O. Dietzsch; L. Ding; A. Dion; J. H. Do; M. Donadelli; O. Drapier; A. Drees; K. A. Drees; A. K. Dubey; J. M. Durham; A. Durum; D. Dutta; V. Dzhordzhadze; L. D'Orazio; S. Edwards; Y. V. Efremenko; J. Egdemir; F. Ellinghaus; W. S. Emam; T. Engelmore; A. Enokizono; H. En'yo; S. Esumi; K. O. Eyser; B. Fadem; N. Feege; D. E. Fields; M. Finger; M. Finger; \\, Jr.; F. Fleuret; S. L. Fokin; Z. Fraenkel; J. E. Frantz; A. Franz; A. D. Frawley; K. Fujiwara; Y. Fukao; T. Fusayasu; S. Gadrat; K. Gainey; C. Gal; P. Gallus; P. Garg; A. Garishvili; I. Garishvili; H. Ge; F. Giordano; A. Glenn; H. Gong; X. Gong; M. Gonin; J. Gosset; Y. Goto; R. Granier de Cassagnac; N. Grau; S. V. Greene; M. Grosse Perdekamp; Y. Gu; T. Gunji; L. Guo; H. Guragain; H. -Ĺ. Gustafsson; T. Hachiya; A. Hadj Henni; C. Haegemann; J. S. Haggerty; K. I. Hahn; H. Hamagaki; J. Hamblen; R. Han; S. Y. Han; J. Hanks; H. Harada; E. P. Hartouni; K. Haruna; S. Hasegawa; K. Hashimoto; E. Haslum; R. Hayano; X. He; M. Heffner; T. K. Hemmick; T. Hester; H. Hiejima; J. C. Hill; R. Hobbs; M. Hohlmann; R. S. Hollis; W. Holzmann; K. Homma; B. Hong; T. Horaguchi; Y. Hori; D. Hornback; T. Hoshino; J. Huang; S. Huang; T. Ichihara; R. Ichimiya; J. Ide; H. Iinuma; Y. Ikeda; K. Imai; Y. Imazu; J. Imrek; M. Inaba; Y. Inoue; A. Iordanova; D. Isenhower; L. Isenhower; M. Ishihara; T. Isobe; M. Issah; A. Isupov; D. Ivanischev; D. Ivanishchev; B. V. Jacak; M. Javani; S. J. Jeon; M. Jezghani; J. Jia; X. Jiang; J. Jin; O. Jinnouchi; B. M. Johnson; E. Joo; K. S. Joo; D. Jouan; D. S. Jumper; F. Kajihara; S. Kametani; N. Kamihara; J. Kamin; M. Kaneta; S. Kaneti; B. H. Kang; J. H. Kang; J. S. Kang; H. Kanou; J. Kapustinsky; K. Karatsu; M. Kasai; D. Kawall; M. Kawashima; A. V. Kazantsev; T. Kempel; J. A. Key; V. Khachatryan; A. Khanzadeev; K. Kihara; K. M. Kijima; J. Kikuchi; B. I. Kim; C. Kim; D. H. Kim; D. J. Kim; E. Kim; E. -J. Kim; H. -J. Kim; H. J. Kim; K. -B. Kim; M. Kim; S. H. Kim; Y. -J. Kim; Y. K. Kim; E. Kinney; K. Kiriluk; Á. Kiss; E. Kistenev; A. Kiyomichi; J. Klatsky; J. Klay; C. Klein-Boesing; D. Kleinjan; P. Kline; T. Koblesky; L. Kochenda; V. Kochetkov; M. Kofarago; Y. Komatsu; B. Komkov; M. Konno; J. Koster; D. Kotchetkov; D. Kotov; A. Kozlov; A. Král; A. Kravitz; F. Krizek; J. Kubart; G. J. Kunde; N. Kurihara; K. Kurita; M. Kurosawa; M. J. Kweon; Y. Kwon; G. S. Kyle; R. Lacey; Y. S. Lai; J. G. Lajoie; A. Lebedev; B. Lee; D. M. Lee; J. Lee; K. Lee; K. B. Lee; K. S. Lee; M. K. Lee; S. H. Lee; S. R. Lee; T. Lee; M. J. Leitch; M. A. L. Leite; M. Leitgab; E. Leitner; B. Lenzi; B. Lewis; X. Li; P. Liebing; S. H. Lim; L. A. Linden Levy; T. Liška; A. Litvinenko; H. Liu; M. X. Liu; B. Love; R. Luechtenborg; D. Lynch; C. F. Maguire; Y. I. Makdisi; M. Makek; A. Malakhov; M. D. Malik; A. Manion; V. I. Manko; E. Mannel; Y. Mao; L. Mašek; H. Masui; S. Masumoto; F. Matathias; M. McCumber; P. L. McGaughey; D. McGlinchey; C. McKinney; N. Means; A. Meles; M. Mendoza; B. Meredith; Y. Miake; T. Mibe; A. C. Mignerey; P. Mikeš; K. Miki; A. J. Miller; T. E. Miller; A. Milov; S. Mioduszewski; D. K. Mishra; M. Mishra; J. T. Mitchell; M. Mitrovski; Y. Miyachi; S. Miyasaka; S. Mizuno; A. K. Mohanty; P. Montuenga; H. J. Moon; T. Moon; Y. Morino; A. Morreale; D. P. Morrison; S. Motschwiller; T. V. Moukhanova; D. Mukhopadhyay; T. Murakami; J. Murata; A. Mwai; T. Nagae; S. Nagamiya; Y. Nagata; J. L. Nagle; M. Naglis; M. I. Nagy; I. Nakagawa; H. Nakagomi; Y. Nakamiya; K. R. Nakamura; T. Nakamura; K. Nakano; C. Nattrass; A. Nederlof; P. K. Netrakanti; J. Newby

    2014-10-09T23:59:59.000Z

    Two-pion interferometry measurements are used to extract the Gaussian radii $R_{{\\rm out}}$, $R_{{\\rm side}}$, and $R_{{\\rm long}}$, of the pion emission sources produced in Cu$+$Cu and Au$+$Au collisions at several beam collision energies $\\sqrt{s_{_{NN}}}$ at PHENIX. The extracted radii, which are compared to recent STAR and ALICE data, show characteristic scaling patterns as a function of the initial transverse size $\\bar{R}$ of the collision systems and the transverse mass $m_T$ of the emitted pion pairs, consistent with hydrodynamiclike expansion. Specific combinations of the three-dimensional radii that are sensitive to the medium expansion velocity and lifetime, and the pion emission time duration show nonmonotonic $\\sqrt{s_{_{NN}}}$ dependencies. The nonmonotonic behaviors exhibited by these quantities point to a softening of the equation of state that may coincide with the critical end point in the phase diagram for nuclear matter.

  1. Centrality, rapidity and transverse momentum dependence of isolated prompt photon production in lead-lead collisions at $\\sqrt{s_{\\mathrm{NN}}} = 2.76$ TeV measured with the ATLAS detector

    E-Print Network [OSTI]

    ATLAS Collaboration

    2015-06-29T23:59:59.000Z

    Prompt photon production in $\\sqrt{s_{\\mathrm{NN}}} = 2.76$ TeV Pb+Pb collisions has been measured by the ATLAS experiment at the Large Hadron Collider using data collected in 2011 with an integrated luminosity of 0.14 nb$^{-1}$. Inclusive photon yields, scaled by the mean nuclear thickness function, are presented as a function of collision centrality and transverse momentum in two pseudorapidity intervals, $|\\eta| leading order perturbative QCD calculations from JETPHOX. The measured cross sections agree well with the predictions for proton-proton collisions within statistical and systematic uncertainties. Both the yields and ratios are also compared to two other pQCD calculations, one which uses the isospin content appropriate to colliding lead nuclei, and another which includes the EPS09 nuclear modifications to the nucleon parton distribution functions.

  2. Neutron interferometric measurement of the scattering length difference between the triplet and singlet states of n-$^3$He

    E-Print Network [OSTI]

    M. G. Huber; M. Arif; W. C. Chen; T. R. Gentile; D. S. Hussey; T. C. Black; D. A. Pushin; C. B. Shahi; F. E. Wietfeldt; L. Yang

    2014-09-30T23:59:59.000Z

    We report a determination of the n-$^3$He scattering length difference $\\Delta b^{\\prime} = b_{1}^{\\prime}-b_{0}^{\\prime} = $ ($-5.411$ $\\pm$ $0.031$ (statistical) $\\pm$ $0.039$ (systematic)) fm between the triplet and singlet states using a neutron interferometer. This revises our previous result $\\Delta b^{\\prime} = $ (-5.610 $\\pm$ $0.027$ (statistical) $\\pm$ $0.032$ (systematic) fm obtained using the same technique in 2008. This revision is due to a re-analysis of the 2008 experiment that includes a more robust treatment of the phase shift caused by magnetic field gradients near the $^3$He cell. Furthermore, we more than doubled our original data set from 2008 by acquiring six months of additional data in 2013. Both the new data set and a re-analysis of the older data are in good agreement. Scattering lengths of low Z isotopes are valued for use in few-body nuclear effective field theories, provide important tests of modern nuclear potential models and in the case of $^3$He aid in the interpretation of neutron scattering from quantum liquids. The difference $\\Delta b^{\\prime}$ was determined by measuring the relative phase shift between two incident neutron polarizations caused by the spin-dependent interaction with a polarized $^3$He target. The target $^3$He gas was sealed inside a small, flat windowed glass cell that was placed in one beam path of the interferometer. The relaxation of $^3$He polarization was monitored continuously with neutron transmission measurements. The neutron polarization and spin flipper efficiency were determined separately using $^3$He analyzers and two different polarimetry analysis methods. A summary of the measured scattering lengths for n-$^3$He with a comparison to nucleon interaction models is given.

  3. Measurement of jet suppression in central Pb-Pb collisions at $\\sqrt{s_{\\rm NN}}$ = 2.76 TeV

    E-Print Network [OSTI]

    ALICE Collaboration

    2015-02-05T23:59:59.000Z

    The transverse momentum ($p_{\\rm T}$) spectrum and nuclear modification factor ($R_{\\rm AA}$) of reconstructed jets in 0-10% and 10-30% central Pb-Pb collisions at $\\sqrt{s_{\\rm NN}}=2.76$ TeV were measured. Jets were reconstructed from charged and neutral particles, utilizing the ALICE tracking detectors and Electromagnetic Calorimeter (EMCal), with the anti-$k_{\\rm T}$ jet algorithm with a resolution parameter of R=0.2. The jet $p_{\\rm T}$ spectra are reported in the pseudorapidity interval of $|{\\eta}_{\\rm jet}|5$ GeV/$c$ to suppress jets constructed from the combinatorial background in Pb-Pb collisions. The effect of the leading charged particle requirement has been studied in both pp and Pb-Pb collisions and has been shown to have negligible effects on the $R_{\\rm AA}$ within the uncertainties of the measurement. The nuclear modification factor is obtained by dividing the jet spectrum measured in Pb-Pb by that in pp collisions scaled by the number of independent nucleon-nucleon collisions estimated using a Glauber model. $R_{\\rm AA}$ is found to be $0.28\\pm0.04$ in 0-10% and $0.35\\pm0.04$ in 10-30% collisions, independent of $p_{\\rm T,jet}$ within the uncertainties of the measurement. The observed suppression is in fair agreement with expectations from two model calculations with different approaches to jet quenching.

  4. University of Washington, Nuclear Physics Laboratory annual report, 1995

    SciTech Connect (OSTI)

    NONE

    1995-04-01T23:59:59.000Z

    The Nuclear Physics Laboratory of the University of Washington supports a broad program of experimental physics research. The current program includes in-house research using the local tandem Van de Graff and superconducting linac accelerators and non-accelerator research in double beta decay and gravitation as well as user-mode research at large accelerator and reactor facilities around the world. This book is divided into the following areas: nuclear astrophysics; neutrino physics; nucleus-nucleus reactions; fundamental symmetries and weak interactions; accelerator mass spectrometry; atomic and molecular clusters; ultra-relativistic heavy ion collisions; external users; electronics, computing, and detector infrastructure; Van de Graff, superconducting booster and ion sources; nuclear physics laboratory personnel; degrees granted for 1994--1995; and list of publications from 1994--1995.

  5. Technology development for gene discovery and full-length sequencing

    SciTech Connect (OSTI)

    Marcelo Bento Soares

    2004-07-19T23:59:59.000Z

    In previous years, with support from the U.S. Department of Energy, we developed methods for construction of normalized and subtracted cDNA libraries, and constructed hundreds of high-quality libraries for production of Expressed Sequence Tags (ESTs). Our clones were made widely available to the scientific community through the IMAGE Consortium, and millions of ESTs were produced from our libraries either by collaborators or by our own sequencing laboratory at the University of Iowa. During this grant period, we focused on (1) the development of a method for preferential cloning of tissue-specific and/or rare transcripts, (2) its utilization to expedite EST-based gene discovery for the NIH Mouse Brain Molecular Anatomy Project, (3) further development and optimization of a method for construction of full-length-enriched cDNA libraries, and (4) modification of a plasmid vector to maximize efficiency of full-length cDNA sequencing by the transposon-mediated approach. It is noteworthy that the technology developed for preferential cloning of rare mRNAs enabled identification of over 2,000 mouse transcripts differentially expressed in the hippocampus. In addition, the method that we optimized for construction of full-length-enriched cDNA libraries was successfully utilized for the production of approximately fifty libraries from the developing mouse nervous system, from which over 2,500 full-ORF-containing cDNAs have been identified and accurately sequenced in their entirety either by our group or by the NIH-Mammalian Gene Collection Program Sequencing Team.

  6. Collective Phenomena in Heavy Ion Collisions

    E-Print Network [OSTI]

    M. Petrovici; A. Pop

    2009-04-23T23:59:59.000Z

    A review of the main results of detailed flow analysis in highly central and semi-central heavy ion collisions at SIS energies is presented in the first part of this paper. The influence of the mass of the colliding nuclei and centrality on the collective expansion and the information on the equation of state of compressed and hot baryonic matter is discussed. The second part is dedicated to a similar type of analysis, based on the behaviour of the average transverse momentum as a function of mass of different hadrons, at the other extreme of energy range, where free baryonic fireballs are produced. Information on the partonic and hadronic expansion, temperature and degree of thermal equilibrium in p+p and Au+Au central collisions at 200 A.GeV is presented.

  7. Collisions with Black Holes and Deconfined Plasmas

    E-Print Network [OSTI]

    Amsel, Aaron J; Virmani, Amitabh

    2008-01-01T23:59:59.000Z

    We use AdS/CFT to investigate i) high energy collisions with balls of deconfined plasma surrounded by a confining phase and ii) the rapid localized heating of a deconfined plasma. Both of these processes are dual to collisions with black holes, where they result in the nucleation of a new "arm" of the horizon reaching out in the direction of the incident object. We study the resulting non-equilibrium dynamics in a universal limit of the gravitational physics which may indicate universal behavior of deconfined plasmas at large N_c. Process (i) produces "virtual" arms of the plasma ball, while process (ii) can nucleate surprisingly large bubbles of a higher temperature phase.

  8. Collisions with Black Holes and Deconfined Plasmas

    E-Print Network [OSTI]

    Aaron J. Amsel; Donald Marolf; Amitabh Virmani

    2007-12-13T23:59:59.000Z

    We use AdS/CFT to investigate i) high energy collisions with balls of deconfined plasma surrounded by a confining phase and ii) the rapid localized heating of a deconfined plasma. Both of these processes are dual to collisions with black holes, where they result in the nucleation of a new "arm" of the horizon reaching out in the direction of the incident object. We study the resulting non-equilibrium dynamics in a universal limit of the gravitational physics which may indicate universal behavior of deconfined plasmas at large N_c. Process (i) produces "virtual" arms of the plasma ball, while process (ii) can nucleate surprisingly large bubbles of a higher temperature phase.

  9. On transverse energy production in hadron collisions

    E-Print Network [OSTI]

    Andrei Leonidov

    2000-05-01T23:59:59.000Z

    The transverse energy spectrum in the unit rapidity window in p-bar p collisions at 540 GeV c.m.s energy is calculated to the next-to-leading order accuracy O(a_s^3) and compared to the experimental data by UA(2) collaboration. We show that the calculated spectrum starts matching experimental data only at relatively large transverse energy Et=60 GeV and is in essential disagreement with it both in shape and magnitude at lower transverse energies. The data are well reproduced by HIJING Monte-Carlo generator indicating the crucial importance of all-order effects in perturbation theory as well as those of hadronization in describing the transverse energy production in hadron collisions at small and intermediate transverse energies.

  10. The collision of two-kinks defects

    E-Print Network [OSTI]

    T. S. Mendonça; H. P. de Oliveira

    2015-02-13T23:59:59.000Z

    We have investigated the head-on collision of a two-kink and a two-antikink pair that arises as a generalization of the $\\phi^4$ model. We have evolved numerically the Klein-Gordon equation with a new spectral algorithm whose accuracy and convergence were attested by the numerical tests. As a general result, the two-kink pair is annihilated radiating away most of the scalar field. It is possible the production of oscillons-like configurations after the collision that bounce and coalesce to form a small amplitude oscillon at the origin. The new feature is the formation of a sequence of quasi-stationary structures that we have identified as lump-like solutions of non-topological nature. The amount of time these structures survives depends on the fine-tuning of the impact velocity.

  11. Reversing a heavy-ion collision

    E-Print Network [OSTI]

    Mikhail Stephanov; Yi Yin

    2014-04-23T23:59:59.000Z

    We introduce a novel approach to study the longitudinal hydrodynamic expansion of the quark-gluon fluid created in heavy-ion collisions. It consists of two steps: First, we apply the maximum entropy method to reconstruct the freeze-out surface from experimentally measured particle distribution. We then take the output of the reconstruction as the "initial" condition to evolve the system back in time by solving the 1+1 ideal hydrodynamic equations analytically, using the method of Khalatnikov and Landau. We find an approximate Bjorken-like plateau in the energy density vs rapidity profile at the early times, which shrinks with time as the boundary shocks propagate inward. In Bjorken frame, the fluid velocity is close to zero within the plateau, as in the Bjorken solution, but increases outside the plateau. The results carry implications for fully numerical hydrodynamic simulations as well as models of heavy-ion collisions based on gauge-gravity duality.

  12. Dynamics and length distribution of microtubules under force and confinement

    E-Print Network [OSTI]

    Björn Zelinski; Nina Müller; Jan Kierfeld

    2012-12-14T23:59:59.000Z

    We investigate the microtubule polymerization dynamics with catastrophe and rescue events for three different confinement scenarios, which mimic typical cellular environments: (i) The microtubule is confined by rigid and fixed walls, (ii) it grows under constant force, and (iii) it grows against an elastic obstacle with a linearly increasing force. We use realistic catastrophe models and analyze the microtubule dynamics, the resulting microtubule length distributions, and force generation by stochastic and mean field calculations; in addition, we perform stochastic simulations. We also investigate the force dynamics if growth parameters are perturbed in dilution experiments. Finally, we show the robustness of our results against changes of catastrophe models and load distribution factors.

  13. Optical Scattering Lengths in Large Liquid-Scintillator Neutrino Detectors

    E-Print Network [OSTI]

    Michael Wurm; Franz von Feilitzsch; Marianne Goeger-Neff; Martin Hofmann; Tobias Lachenmaier; Timo Lewke; Teresa Marrodan Undagoitita; Quirin Meindl; Randoplh Moellenberg; Lothar Oberauer; Walter Potzel; Marc Tippmann; Sebastian Todor; Christoph Traunsteiner; Juergen Winter

    2010-04-06T23:59:59.000Z

    For liquid-scintillator neutrino detectors of kiloton scale, the transparency of the organic solvent is of central importance. The present paper reports on laboratory measurements of the optical scattering lengths of the organic solvents PXE, LAB, and Dodecane which are under discussion for next-generation experiments like SNO+, Hanohano, or LENA. Results comprise the wavelength range from 415 to 440nm. The contributions from Rayleigh and Mie scattering as well as from absorption/re-emission processes are discussed. Based on the present results, LAB seems to be the preferred solvent for a large-volume detector.

  14. Static Length Scales of N=6 Chern-Simons Plasma

    E-Print Network [OSTI]

    Dongsu Bak; Kazem Bitaghsir Fadafan; Hyunsoo Min

    2010-04-19T23:59:59.000Z

    Using gravity description, we compute various static length scales of N=6 Chern Simons plasma in a strongly coupled regime. For this, we consider the CP3 compactification of the type IIA supergravity down to four dimensions, and identify all the low-lying bosonic modes up to masses corresponding to the operator dimension 3 together with all the remaining CP3 invariant modes. We find the true mass gap, the Debye screening mass and the corresponding dual operators to be probed in the field theory side.

  15. Varying properties along lengths of temperature limited heaters

    DOE Patents [OSTI]

    Vinegar, Harold J. (Bellaire, TX); Xie, Xueying (Houston, TX); Miller, David Scott (Katy, TX); Ginestra, Jean Charles (Richmond, TX)

    2011-07-26T23:59:59.000Z

    A system for heating a subsurface formation is described. The system includes an elongated heater in an opening in the formation. The elongated heater includes two or more portions along the length of the heater that have different power outputs. At least one portion of the elongated heater includes at least one temperature limited portion with at least one selected temperature at which the portion provides a reduced heat output. The heater is configured to provide heat to the formation with the different power outputs. The heater is configured so that the heater heats one or more portions of the formation at one or more selected heating rates.

  16. The K+ K+ scattering length from Lattice QCD

    SciTech Connect (OSTI)

    Silas Beane; Thomas Luu; Konstantinos Orginos; Assumpta Parreno; Martin Savage; Aaron Torok; Andre Walker-Loud

    2007-09-11T23:59:59.000Z

    The K+K+ scattering length is calculated in fully-dynamical lattice QCD with domain-wall valence quarks on the MILC asqtad-improved gauge configurations with fourth-rooted staggered sea quarks. Three-flavor mixed-action chiral perturbation theory at next-to-leading order, which includes the leading effects of the finite lattice spacing, is used to extrapolate the results of the lattice calculation to the physical value of mK + /fK + . We find mK^+ aK^+ K^+ = â~0.352 ± 0.016, where the statistical and systematic errors have been combined in quadrature.

  17. Self-aligned submicron gate length gallium arsenide MESFET 

    E-Print Network [OSTI]

    Huang, Hsien-Ching

    1987-01-01T23:59:59.000Z

    38 21. Proximity cap annealing . 22. Temperature profile of post implant anneal 46 47 23. 24. 25. 26. 27. 28. 29. 30. "Pits" or holes in GaAs post implant anneal without sacrificial cap Silicon monoxide source (bafile box) used.... 16(b)). The bottom resist layer is then further etched in the oxygen plasma to produce undercutting for the desire gate structure. The amount of undercut is determined by the desired length of the gate and is the width of the remaining resist...

  18. Pauling bond strength, bond length and electron density distribution

    SciTech Connect (OSTI)

    Gibbs, Gerald V.; Ross, Nancy L.; Cox, David F.; Rosso, Kevin M.; Iversen, Bo B.; Spackman, M. A.

    2014-01-18T23:59:59.000Z

    A power law regression equation, = 1.46(/r)-0.19, connecting the average experimental bond lengths, , with the average accumulation of the electron density at the bond critical point, , between bonded metal M and oxygen atoms, determined at ambient conditions for oxide crystals, where r is the row number of the M atom, is similar to the regression equation R(M-O) = 1.39(?(rc)/r)-0.21 determined for three perovskite crystals for pressures as high as 80 GPa. The two equations are also comparable with those, = 1.43(/r)-0.21, determined for a large number of oxide crystals at ambient conditions and = 1.39(/r)-0.22, determined for geometry optimized hydroxyacid molecules, that connect the bond lengths to the average Pauling electrostatic bond strength, , for the M-O bonded interactions. On the basis of the correspondence between the two sets of equations connecting ?(rc) and the Pauling bond strength s with bond length, it appears that Pauling’s simple definition of bond strength closely mimics the accumulation of the electron density between bonded pairs of atoms. The similarity of the expressions for the crystals and molecules is compelling evidence that the M-O bonded interactions for the crystals and molecules 2 containing the same bonded interactions are comparable. Similar expressions, connecting bond lengths and bond strength, have also been found to hold for fluoride, nitride and sulfide molecules and crystals. The Brown-Shannon bond valence, ?, power law expression ? = [R1/(R(M-O)]N that has found wide use in crystal chemistry, is shown to be connected to a more universal expression determined for oxides and the perovskites, = r[(1.41)/]4.76, demonstrating that the bond valence for a bonded interaction is likewise closely connected to the accumulation of the electron density between the bonded atoms. Unlike the Brown-Shannon expression, it is universal in that it holds for the M-O bonded interactions for a relatively wide range of M atoms of the periodic table. The power law equation determined for the oxide crystals at ambient conditions is similar to the power law expression = r[1.46/]5.26 determined for the perovskites at pressures as high as 80 GPa, indicating that the intrinsic connection between R(M-O) and ?(rc) that holds at ambient conditions also holds, to a first approximation, at high pressures.

  19. Fast Collision Detection between Geometric Models

    E-Print Network [OSTI]

    North Carolina at Chapel Hill, University of

    John Canny ~ ~\\::> f a--·J. s -\\-o ~\\;.V\\ 0 ~{_\\:.\\':> ~0~~ iL ~ dO L~C. ' \\\\f\\,1~ 11 r -.~ 0... o..t. The importance of collision detection extends to other areas like robot motion planning and it has been extensively studied in robotics and computational geometry for more than a decade [3, 4, 5, 11, 16, 18]. But

  20. Diffractive Higgs boson photoproduction in peripheral collisions

    E-Print Network [OSTI]

    M. B. Gay Ducati; G. G. Silveira

    2008-12-05T23:59:59.000Z

    An alternative process is proposed for the diffractive Higgs boson production in peripheral $pp$ collisions, exploring it through the photon-proton interaction by Double Pomeron Exchange. It is estimated the event rate of the diffractive Higgs production in central rapidity for Tevatron and LHC energies, being of the order of 1 fb, in agreement to the predictions from other diffractive processes. The results are confronted with those obtained from a similar approach of the Durham group.

  1. Gravity waves from cosmic bubble collisions

    SciTech Connect (OSTI)

    Salem, Michael P.; Saraswat, Prashant; Shaghoulian, Edgar, E-mail: mpsalem@stanford.edu, E-mail: ps88@stanford.edu, E-mail: edgars@stanford.edu [Stanford Institute for Theoretical Physics and Department of Physics, Stanford University, Stanford, California 94305 (United States)

    2013-02-01T23:59:59.000Z

    Our local Hubble volume might be contained within a bubble that nucleated in a false vacuum with only two large spatial dimensions. We study bubble collisions in this scenario and find that they generate gravity waves, which are made possible in this context by the reduced symmetry of the global geometry. These gravity waves would produce B-mode polarization in the cosmic microwave background, which could in principle dominate over the inflationary background.

  2. Strangeness equilibration in heavy ion collisions

    E-Print Network [OSTI]

    Pal, S.; Ko, Che Ming; Lin, ZW.

    2001-01-01T23:59:59.000Z

    is mainly elastic through the K* resonance, is neglected in the model. Since pions appear only at later stage of the collision from delta Strangeness equilibratio Subrata Pal, C. M. Cyclotron Institute and Physics Department, Texas ~Received 15 May... in Ref. @17# includes kaon production from both baryon-baryon and meson-baryon interactions. For kaon production from baryon-baryon inter- ?2001 The American Physical Society1 RAPID COMMUNICATIONS SUBRATA PAL, C. M. KO, AND ZI-WEI LIN PHYSICAL REVIEW...

  3. The Nuclear Revolution, Relative Gains, and International Nuclear Assistance

    E-Print Network [OSTI]

    Kroenig, Matthew

    2006-01-01T23:59:59.000Z

    it would transfer nuclear technology. Washington Post. 26preferences: the export of sensitive nuclear technology.export of sensitive nuclear technology presents a kind of

  4. Dynamics of nuclear envelope and nuclear pore complex formation

    E-Print Network [OSTI]

    Anderson, Daniel J.

    2008-01-01T23:59:59.000Z

    Limited expression of nuclear pore membrane glycoprotein 210suggests cell-type specific nuclear pores in metazoans. Expand Dultz, E. (2008). Nuclear pore complex assembly through

  5. Effects of overlapping strings in pp collisions

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

    Bierlich, Christian; Gustafson, Gösta; Lönnblad, Leif; Tarasov, Andrey

    2015-03-01T23:59:59.000Z

    In models for hadron collisions based on string hadronization, the strings are usually treated as independent, allowing no interaction between the confined colour fields. In studies of nucleus collisions it has been suggested that strings close in space can fuse to form "colour ropes." Such ropes are expected to give more strange particles and baryons, which also has been suggested as a signal for plasma formation. Overlapping strings can also be expected in pp collisions, where usually no phase transition is expected. In particular at the high LHC energies the expected density of strings is quite high. To investigate possiblemore »effects of rope formation, we present a model in which strings are allowed to combine into higher multiplets, giving rise to increased production of baryons and strangeness, or recombine into singlet structures and vanish. Also a crude model for strings recombining into junction structures is considered, again giving rise to increased baryon production. The models are implemented in the DIPSY MC event generator, using PYTHIA8 for hadronization, and comparison to pp minimum bias data, reveals improvement in the description of identified particle spectra.« less

  6. Effects of Overlapping Strings in pp Collisions

    E-Print Network [OSTI]

    Christian Bierlich; Gösta Gustafson; Leif Lönnblad; Andrey Tarasov

    2015-02-13T23:59:59.000Z

    In models for hadron collisions based on string hadronization, the strings are usually treated as independent, allowing no interaction between the confined colour fields. In studies of nucleus collisions it has been suggested that strings close in space can fuse to form "colour ropes". Such ropes are expected to give more strange particles and baryons, which also has been suggested as a signal for plasma formation. Overlapping strings can also be expected in pp collisions, where usually no phase transition is expected. In particular at the high LHC energies the expected density of strings is quite high. To investigate possible effects of rope formation, we present a model in which strings are allowed to combine into higher multiplets, giving rise to increased production of baryons and strangeness, or recombine into singlet structures and vanish. Also a crude model for strings recombining into junction structures is considered, again giving rise to increased baryon production. The models are implemented in the DIPSY MC event generator, using PYTHIA 8 for hadronization, and comparison to pp minimum bias data, reveals improvement in the description of identified particle spectra.

  7. Effects of overlapping strings in pp collisions

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

    Bierlich, Christian [Lund University; Gustafson, Gösta [Lund University; Lönnblad, Leif [Lund University; Tarasov, Andrey [JLAB

    2015-03-01T23:59:59.000Z

    In models for hadron collisions based on string hadronization, the strings are usually treated as independent, allowing no interaction between the confined colour fields. In studies of nucleus collisions it has been suggested that strings close in space can fuse to form "colour ropes." Such ropes are expected to give more strange particles and baryons, which also has been suggested as a signal for plasma formation. Overlapping strings can also be expected in pp collisions, where usually no phase transition is expected. In particular at the high LHC energies the expected density of strings is quite high. To investigate possible effects of rope formation, we present a model in which strings are allowed to combine into higher multiplets, giving rise to increased production of baryons and strangeness, or recombine into singlet structures and vanish. Also a crude model for strings recombining into junction structures is considered, again giving rise to increased baryon production. The models are implemented in the DIPSY MC event generator, using PYTHIA8 for hadronization, and comparison to pp minimum bias data, reveals improvement in the description of identified particle spectra.

  8. Isospin diffusion in semi-peripheral $^{58}Ni$ + $^{197}Au$ collisions at intermediate energies (II): Dynamical simulations

    E-Print Network [OSTI]

    E. Galichet; M. Colonna; B. Borderie; M. F. Rivet

    2008-12-15T23:59:59.000Z

    We study isospin effects in semi-peripheral collisions above the Fermi energy by considering the symmetric $^{58}Ni$ + $^{58}Ni$ and the asymmetric reactions $^{58}Ni$ + $^{197}Au$ over the incident energy range 52-74 A MeV. A microscopic transport model with two different parameterizations of the symmetry energy term is used to investigate the isotopic content of pre-equilibrium emission and the N/Z diffusion process. Simulations are also compared to experimental data obtained with the INDRA array and bring information on the degree of isospin equilibration observed in Ni + Au collisions. A better overall agreement between data and simulations is obtained when using a symmetry term which linearly increases with nuclear density.

  9. Wisconsin Nuclear Profile - Point Beach Nuclear Plant

    U.S. Energy Information Administration (EIA) Indexed Site

    Point Beach Nuclear Plant" "Unit","Summer capacity (mw)","Net generation (thousand mwh)","Summer capacity factor (percent)","Type","Commercial operation date","License expiration...

  10. Tennessee Nuclear Profile - Watts Bar Nuclear Plant

    U.S. Energy Information Administration (EIA) Indexed Site

    Watts Bar Nuclear Plant" "Unit","Summer capacity (mw)","Net generation (thousand mwh)","Summer capacity factor (percent)","Type","Commercial operation date","License expiration...

  11. Massachusetts Nuclear Profile - Pilgrim Nuclear Power Station

    U.S. Energy Information Administration (EIA) Indexed Site

    Pilgrim Nuclear Power Station" "Unit","Summer capacity (mw)","Net generation (thousand mwh)","Summer cpacity factor (percent)","Type","Commercial operation date","License...

  12. Arkansas Nuclear Profile - Arkansas Nuclear One

    U.S. Energy Information Administration (EIA) Indexed Site

    Nuclear One" "Unit","Summer capacity (mw)","Net generation (thousand mwh)","Summer capacity factor (percent)","Type","Commercial operation date","License expiration date"...

  13. Probing the Conformational Distributions of Sub-Persistence Length DNA

    SciTech Connect (OSTI)

    Mastroianni, Alexander; Sivak, David; Geissler, Phillip; Alivisatos, Paul

    2009-06-08T23:59:59.000Z

    We have measured the bending elasticity of short double-stranded DNA (dsDNA) chains through small-angle X-ray scattering from solutions of dsDNA-linked dimers of gold nanoparticles. This method, which does not require exertion of external forces or binding to a substrate, reports on the equilibrium distribution of bending fluctuations, not just an average value (as in ensemble FRET) or an extreme value (as in cyclization), and in principle provides a more robust data set for assessing the suitability of theoretical models. Our experimental results for dsDNA comprising 42-94 basepairs (bp) are consistent with a simple worm-like chain model of dsDNA elasticity, whose behavior we have determined from Monte Carlo simulations that explicitly represent nanoparticles and their alkane tethers. A persistence length of 50 nm (150 bp) gave a favorable comparison, consistent with the results of single-molecule force-extension experiments on much longer dsDNA chains, but in contrast to recent suggestions of enhanced flexibility at these length scales.

  14. The bound coherent neutron scattering length of the oxygen isotopes

    SciTech Connect (OSTI)

    Fischer, Henry E [Institut Laue-Langevin (ILL); Simonson, J Michael {Mike} [ORNL; Neuefeind, Joerg C [ORNL; Lemmel, Hartmut [Technical University Vienna; Rauch, Helmut [E141 Atominstitut der Österreichischen Universitäten,; Zeidler, Anita [University of Bath; Salmon, Phil [University of Bath

    2012-01-01T23:59:59.000Z

    The technique of neutron interferometry was used to measure the bound coherent neutron scattering length bcoh of the oxygen isotopes 17O and 18O. From the measured difference in optical path between two water samples, either H2 17O or H2 18O versus H2 natO, where nat denotes the natural isotopic composition, we obtain bcoh , 17O = 5.867(4) fm and bcoh , 18O = 6.009(5) fm, based on the accurately known value of bcoh , natO = 5.805(4) fm which is equal to bcoh , 16O within the experimental uncertainty. Our results for bcoh , 17O and bcoh , 18O differ appreciably from the standard tabulated values of 5.6(5) fm and 5.84(7) fm, respectively. In particular, our measured scattering length contrast of 0.204(3) fm between 18O and natO is nearly a factor of 6 greater than the tabulated value, which renders feasible neutron diffraction experiments using 18O isotope substitution and thereby offers new possibilites for measuring the partial structure factors of oxygen-containing compounds, such as water.

  15. Beyond Mixing-length Theory: a step toward 321D

    E-Print Network [OSTI]

    Arnett, W David; Viallet, Maxime; Campbell, Simon W; Lattanzio, John; Mo?ak, Miroslav

    2015-01-01T23:59:59.000Z

    We present a physical basis for algorithms to replace mixing-length theory (MLT) in stellar evolutionary computations. The 321D procedure is based on three-dimensional (3D) time-dependent solutions of the Navier-Stokes equations, including the Kolmogorov cascade as a sub-grid model of dissipation (implicit large eddy simulations; ILES). We use Reynolds-averaged Navier-Stokes (RANS) averaging to make 3D simulation data concise, and use 3D simulations to give RANS closure. We sketch a simple algorithm, which is non-local and time-dependent, with both MLT and the Lorenz convective roll as particular subsets of solutions. The damping length is determined from a balance between the large-scale driving and damping at the Kolmogorov scale. We find that (1) braking regions (boundary layers in which mixing occurs) automatically appear {\\it beyond} the edges of convection as defined by the Schwarzschild criterion, (2) dynamic (non-local) terms imply a non-zero turbulent kinetic energy flux (unlike MLT), (3) the effects...

  16. Cooling Configuration Design Considerations for Long-Length HTS Cables

    SciTech Connect (OSTI)

    Demko, Jonathan A [ORNL; Duckworth, Robert C [ORNL

    2009-01-01T23:59:59.000Z

    Recent successes in demonstrating high temperature superconducting (HTS) cable systems hundreds of meters in length have inspired even longer length projects. A compact and energy efficient cooling configuration can be achieved using a counterflow-cooling arrangement. This is particularly attractive when all three phases are contained in a single cryostat because of the elimination of the space and thermal requirements of a separate liquid nitrogen return line. Future cable projects will utilize second generation (2G) wire which is expected to become lower in cost but may have different thermal requirements than first generation (1G) BSCCO wire due to the lower critical temperature and to a lesser extent, the lower thermal conductivity of the wire. HTS cable configurations will be studied with a numerical model to assess thermal hydraulic performance with AC and thermal losses; a summary of the results from the analysis will be presented. An analysis of the cable thermal- hydraulic response to over-current faults will be presented.

  17. The Chain-Length Distribution in Subcritical Systems

    SciTech Connect (OSTI)

    Steven Douglas Nolen

    2000-06-01T23:59:59.000Z

    The individual fission chains that appear in any neutron multiplying system provide a means, via neutron noise analysis, to unlock a wealth of information regarding the nature of the system. This work begins by determining the probability density distributions for fission chain lengths in zero-dimensional systems over a range of prompt neutron multiplication constant (K) values. This section is followed by showing how the integral representation of the chain-length distribution can be used to obtain an estimate of the system's subcritical prompt multiplication (MP). The lifetime of the chains is then used to provide a basis for determining whether a neutron noise analysis will be successful in assessing the neutron multiplication constant, k, of the system in the presence of a strong intrinsic source. A Monte Carlo transport code, MC++, is used to model the evolution of the individual fission chains and to determine how they are influenced by spatial effects. The dissertation concludes by demonstrating how experimental validation of certain global system parameters by neutron noise analysis may be precluded in situations in which the system K is relatively low and in which realistic detector efficiencies are simulated.

  18. Suppression of inclusive J/$\\mathbf?$ and $\\mathbf?$(2S) production in p-Pb collisions with ALICE at the LHC

    E-Print Network [OSTI]

    Biswarup Paul; for the ALICE Collaboration

    2014-12-18T23:59:59.000Z

    The ALICE Collaboration has studied inclusive J/$\\psi$ and $\\psi$(2S) production in p-Pb collisions at $\\sqrt{s_{\\rm NN}} = 5.02$ TeV with the Muon Spectrometer. The measurement was performed at forward (2.03 $nuclear modification factor of J/$\\psi$ and $\\psi$(2S) has been measured as a function of transverse momentum and event activity. Theoretical models based on nuclear shadowing, coherent energy loss or both are in reasonable agreement with the J/$\\psi$ results but cannot describe the $\\psi$(2S) behaviour. Other mechanisms must be invoked in order to explain the $\\psi$(2S) suppression in p-Pb collisions.

  19. Quantum electrodynamics in a laser and the electron laser collision

    E-Print Network [OSTI]

    Qi-Ren Zhang

    2014-08-08T23:59:59.000Z

    Quantum electrodynamics in a laser is formulated, in which the electron-laser interaction is exactly considered, while the interaction of an electron and a single photon is considered by perturbation. The formulation is applied to the electron-laser collisions. The effect of coherence between photons in the laser is therefore fully considered in these collisions. The possibility of $\\gamma-$ray laser generation by use of this kind of collision is discussed.

  20. Simulated nuclear reactor fuel assembly

    DOE Patents [OSTI]

    Berta, Victor T. (Idaho Falls, ID)

    1993-01-01T23:59:59.000Z

    An apparatus for electrically simulating a nuclear reactor fuel assembly. It includes a heater assembly having a top end and a bottom end and a plurality of concentric heater tubes having electrical circuitry connected to a power source, and radially spaced from each other. An outer target tube and an inner target tube is concentric with the heater tubes and with each other, and the outer target tube surrounds and is radially spaced from the heater tubes. The inner target tube is surrounded by and radially spaced from the heater tubes and outer target tube. The top of the assembly is generally open to allow for the electrical power connection to the heater tubes, and the bottom of the assembly includes means for completing the electrical circuitry in the heater tubes to provide electrical resistance heating to simulate the power profile in a nuclear reactor. The embedded conductor elements in each heater tube is split into two halves for a substantial portion of its length and provided with electrical isolation such that each half of the conductor is joined at one end and is not joined at the other end.