Sample records for g-1cm2 nuclear collision

  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. 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.

  3. 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

  4. 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.

  5. 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

  6. 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.

  7. 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

  8. 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

  9. 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.

  10. 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.

  11. 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.

  12. 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...

  13. 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...

  14. 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.

  15. 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

  16. 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

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  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

    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...

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. $J/?$ 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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...

  18. 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,

  19. 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...

  20. 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.

  1. 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...

  2. 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.

  3. 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

  4. 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...

  5. 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...

  6. 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...

  7. 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.

  8. 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).

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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...

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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

  1. 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.

  2. 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.

  3. $\\eta$ 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...

  4. 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.

  5. 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.

  6. 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.

  7. 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...

  8. 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.

  9. 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).

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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...

  5. 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

  6. 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.

  7. 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.

  8. 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.

  9. 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].

  10. 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.

  11. 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...

  12. 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...

  13. 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...

  14. 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.

  15. 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.

  16. 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...

  17. 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.

  18. 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

  19. 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.

  20. 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...

  1. 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

  2. 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...

  3. 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).

  4. 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.

  5. 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.

  6. 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.

  7. ? 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.

  8. 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. ...

  9. 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.

  10. 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.

  11. 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.

  12. 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

  13. 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)

  14. 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.

  15. 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.

  16. 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...

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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...

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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

  8. 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.

  9. 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.

  10. 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

  11. 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,

  12. 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.

  13. 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.

  14. 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 ...

  15. 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.

  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. 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...

  18. 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.

  19. 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.

  20. 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

  1. 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

  2. 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.

  3. 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

  4. 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.

  5. 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...

  6. 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.

  7. $J/?$ 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.

  8. 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}

  9. 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 ...

  10. 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.

  11. 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....

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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

  5. {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.

  6. 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...

  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 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...

  10. 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.

  11. 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.

  12. 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...

  13. 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.

  14. 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.

  15. 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.``

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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...

  2. 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...

  3. 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...

  4. 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

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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

  11. 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.

  12. 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).

  13. 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.

  14. 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.

  15. 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 ...

  16. 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.

  17. 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...

  18. 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.

  19. 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.

  20. 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.

  1. 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

  2. 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

  3. 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).

  4. 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)

  5. 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)

  6. 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.

  7. 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

  8. 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 .

  9. 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.

  10. $J/?$ 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.

  11. $J/?$ 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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...

  16. 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.

  17. 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

  18. 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...

  19. 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

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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...

  5. 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

  6. 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

  7. 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.

  8. 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.

  9. 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

  10. 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

  11. 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)

  12. 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.

  13. 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.

  14. 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

  15. 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.

  16. 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.

  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. 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

  3. 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.

  4. 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.

  5. 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.

  6. 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...

  7. 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.

  8. 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.

  9. 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.

  10. 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

  11. 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...

  12. 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.

  13. 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.

  14. 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.

  15. 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...

  16. 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.

  17. 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.

  18. 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...

  19. 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...

  20. 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.

  1. 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

  2. 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)...

  3. 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

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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

  13. 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...

  14. 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

  15. 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.

  16. 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.

  17. 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.

  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. 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.

  16. 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

  17. 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.

  18. 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.

  19. 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.

  20. 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

  1. 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.

  2. 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).

  3. 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).

  4. 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

  5. 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...

  6. 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.

  7. 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...

  8. 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...

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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...

  14. 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...

  15. 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...

  16. 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.

  17. 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.

  18. $J/?$ 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.

  19. 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.

  20. 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

  1. 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.

  2. 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.

  3. 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.

  4. 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

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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/$c$.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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

  2. 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.

  3. 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

  4. 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.

  5. 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...

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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

  17. 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.

  18. 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.

  19. 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...

  20. 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

  1. 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

  2. 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

  3. 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.

  4. 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.

  5. 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.

  6. 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...

  7. 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...

  8. 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...

  9. 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"...

  10. 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.

  11. 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.

  12. Measurement of $?$(1S+2S+3S) production in $p$$+$$p$ and Au$+$Au collisions at $\\sqrt{s_{_{NN}}}=200$ GeV

    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; A. Angerami; K. Aoki; N. Apadula; L. Aphecetche; Y. Aramaki; 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; 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; S. Belikov; R. Belmont; R. Bennett; A. Berdnikov; Y. Berdnikov; A. A. Bickley; X. Bing; D. S. Blau; J. G. Boissevain; J. S. Bok; H. Borel; K. Boyle; M. L. Brooks; H. Buesching; V. Bumazhnov; G. Bunce; S. Butsyk; C. M. Camacho; S. Campbell; P. Castera; B. S. Chang; W. C. Chang; J. -L. Charvet; C. -H. Chen; S. Chernichenko; C. Y. Chi; 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; B. A. Cole; M. Connors; P. Constantin; M. Csanád; T. Csörg?; T. Dahms; S. Dairaku; K. Das; A. Datta; M. S. Daugherity; G. David; A. Denisov; D. d'Enterria; A. Deshpande; E. J. Desmond; K. V. Dharmawardane; O. Dietzsch; L. Ding; A. Dion; 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; F. Ellinghaus; T. Engelmore; A. Enokizono; H. En'yo; S. Esumi; K. O. Eyser; B. Fadem; 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; K. Gainey; C. Gal; A. Garishvili; I. Garishvili; A. Glenn; H. Gong; X. Gong; M. Gonin; J. Gosset; Y. Goto; R. Granier de Cassagnac; N. Grau; S. V. Greene; M. Grosse Perdekamp; T. Gunji; L. Guo; H. -Ĺ. Gustafsson; T. Hachiya; A. Hadj Henni; J. S. Haggerty; K. I. Hahn; H. Hamagaki; R. Han; J. Hanks; E. P. Hartouni; K. Haruna; K. Hashimoto; E. Haslum; R. Hayano; X. He; M. Heffner; T. K. Hemmick; T. Hester; J. C. Hill; M. Hohlmann; R. S. Hollis; W. Holzmann; K. Homma; B. Hong; T. Horaguchi; Y. Hori; D. Hornback; S. Huang; T. Ichihara; R. Ichimiya; H. Iinuma; Y. Ikeda; K. Imai; J. Imrek; M. Inaba; A. Iordanova; D. Isenhower; M. Ishihara; T. Isobe; M. Issah; A. Isupov; D. Ivanischev; D. Ivanishchev; B. V. Jacak; M. Javani; J. Jia; X. Jiang; J. Jin; B. M. Johnson; K. S. Joo; D. Jouan; D. S. Jumper; F. Kajihara; S. Kametani; N. Kamihara; J. Kamin; S. Kaneti; B. H. Kang; J. H. Kang; J. S. Kang; J. Kapustinsky; K. Karatsu; M. Kasai; D. Kawall; A. V. Kazantsev; T. Kempel; A. Khanzadeev; K. M. Kijima; J. Kikuchi; B. I. Kim; C. Kim; D. H. Kim; D. J. Kim; E. Kim; E. -J. Kim; H. J. Kim; K. -B. Kim; S. H. Kim; Y. -J. Kim; Y. K. Kim; E. Kinney; K. Kiriluk; Á. Kiss; E. Kistenev; J. Klatsky; J. Klay; C. Klein-Boesing; D. Kleinjan; P. Kline; L. Kochenda; Y. Komatsu; B. Komkov; M. Konno; J. Koster; D. Kotchetkov; D. Kotov; A. Kozlov; A. Král; A. Kravitz; F. Krizek; G. J. Kunde; K. Kurita; M. Kurosawa; M. J. Kweon; Y. Kwon; G. S. Kyle; R. Lacey; Y. S. Lai; J. G. Lajoie; D. Layton; A. Lebedev; B. Lee; D. M. Lee; J. Lee; K. B. Lee; K. S. Lee; S. H. Lee; S. R. Lee; T. Lee; M. J. Leitch; M. A. L. Leite; M. Leitgab; 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; 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; M. Mendoza; B. Meredith; Y. Miake; T. Mibe; A. C. Mignerey; P. Mikeš; K. Miki; A. Milov; D. K. Mishra; M. Mishra; J. T. Mitchell; Y. Miyachi; S. Miyasaka; A. K. Mohanty; H. J. Moon; Y. Morino; A. Morreale; D. P. Morrison; S. Motschwiller; T. V. Moukhanova; D. Mukhopadhyay; T. Murakami; J. Murata; T. Nagae; S. Nagamiya; J. L. Nagle; M. Naglis; M. I. Nagy; I. Nakagawa; Y. Nakamiya; K. R. Nakamura; T. Nakamura; K. Nakano; C. Nattrass; A. Nederlof; J. Newby; M. Nguyen; M. Nihashi; T. Niida; R. Nouicer; N. Novitzky; A. S. Nyanin; E. O'Brien; S. X. Oda; C. A. Ogilvie; M. Oka; K. Okada; Y. Onuki; A. Oskarsson; M. Ouchida; K. Ozawa; R. Pak; A. P. T. Palounek; V. Pantuev; V. Papavassiliou; B. H. Park; I. H. Park; J. Park; S. K. Park; W. J. Park; S. F. Pate; L. Patel; H. Pei; J. -C. Peng; H. Pereira; V. Peresedov; D. Yu. Peressounko; R. Petti; C. Pinkenburg; R. P. Pisani; M. Proissl; M. L. Purschke; A. K. Purwar; H. Qu; J. Rak; A. Rakotozafindrabe; I. Ravinovich; K. F. Read; S. Rembeczki; K. Reygers; D. Reynolds; V. Riabov; Y. Riabov; E. Richardson; N. Riveli; D. Roach; G. Roche; S. D. Rolnick; M. Rosati; S. S. E. Rosendahl; P. Rosnet; P. Rukoyatkin; P. Ruži?ka; V. L. Rykov; B. Sahlmueller; N. Saito; T. Sakaguchi; S. Sakai; K. Sakashita; V. Samsonov; M. Sano; M. Sarsour; T. Sato; S. Sawada; K. Sedgwick; J. Seele

    2015-04-01T23:59:59.000Z

    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 $\\Upsilon$ states, $\\Upsilon(1S+2S+3S)$, was measured in the PHENIX experiment via electron-positron decay pairs at midrapidity for Au$+$Au and $p$$+$$p$ collisions at $\\sqrt{s_{_{NN}}}=200$ GeV. The $\\Upsilon(1S+2S+3S)\\rightarrow e^+e^-$ differential cross section at midrapidity was found to be $B_{\\rm ee} d\\sigma/dy =$ 108 $\\pm$ 38 (stat) $\\pm$ 15(syst) $\\pm$ 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 $\\Upsilon$ state yield relative to the extrapolation from $p$$+$$p$ collision data. The suppression is consistent with measurements made by STAR at RHIC and at higher energies by the CMS experiment at the Large Hadron Collider.

  13. Pion, kaon, proton and anti-proton transverse momentum distributions from p+p and d+Au collisions at sqrt(sNN) = 200 GeV

    SciTech Connect (OSTI)

    Adams, J.; Adler, C.; Aggarwal, M.M.; Ahammed, Z.; Amonett, J.; Anderson, B.D.; Anderson, M; 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.; Bhaskar, P.; 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.; Castro, M.; Cebra, D.; Chaloupka, P.; Chattopadhyay, S.; Chen, H.F.; Chen, Y.; Chernenko, S.P.; Cherney, M.; Chikanian, A.; Choi, B.; 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, 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.; Ganti, M.S.; Gutierrez, T.D.; Gagunashvili, N.; Gans, J.; Gaudichet, L.; Germain, M.; Geurts, F.; Ghazikhanian, V.; Ghosh, P.; Gonzalez, J.E.; Grachov, O.; Grigoriev, V.; Cronstal, S.; Grosnick, D.; Guedon, M.; Guertin, S.M.; Gupta, A.; 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.; Huang, S.L.; Humanic, T.J.; Igo, G.; Ishihara, A.; Jacobs, P.; Jacobs, W.W.; Janik, M.; Johnson, I.; Jones, P.G.; Judd, E.G.; Kabana, S.; Kaneta, M.; Kaplan, M.; Keane, D.; Kiryluk, J.; Kisiel, A.; Klay, J.; Klein, S.R.; Klyachko, A.; Koetke, D.D.; Kollegger, T.; Konstantinov, A.S.; Kopytine, S.M.; Kotchenda, L.; Kovalenko, A.D.; Kramer, M.; Kravtsov, P.; Krueger, K.; Kuhn, C.; Kulikov, A.I.; Kumar, A.; et al.

    2003-09-16T23:59:59.000Z

    Identified mid-rapidity particle spectra of {pi}{sup {+-}}, K{sup {+-}}, and p({bar p}) from 200 GeV p+p and d+Au collisions are reported. A time-of-flight detector based on multi-gap resistive plate chamber technology is used for particle identification. The particle-species dependence of the Cronin effect is observed to be significantly smaller than that at lower energies. The ratio of the nuclear modification factor (R{sub dAu}) between (p+ {bar p}) and charged hadrons (h) in the transverse momentum range 1.2 < p{sub T} < 3.0 GeV/c is measured to be 1.19 {+-} 0.05(stat) {+-} 0.03(syst) in minimum-bias collisions and shows little centrality dependence. The yield ratio of (p + {bar p})/h in minimum-bias d+Au collisions is found to be a factor of 2 lower than that in Au+Au collisions, indicating that the Cronin effect alone is not enough to account for the relative baryon enhancement observed in heavy ion collisions at RHIC.

  14. Nuclear matter symmetry energy and the neutron skin thickness of heavy nuclei RID A-2398-2009

    E-Print Network [OSTI]

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

    2005-01-01T23:59:59.000Z

    Correlations between the thickness of the neutron skin in finite nuclei and the nuclear matter symmetry energy are studied in the Skyrme Hartree-Fock model. From the most recent analysis of the isospin diffusion data in heavy-ion collisions based...

  15. Is Nuclear Energy the Solution?

    E-Print Network [OSTI]

    Saier, Milton H.; Trevors, Jack T.

    2010-01-01T23:59:59.000Z

    009-0270-y Is Nuclear Energy the Solution? Milton H. Saier &in the last 50 years, nuclear energy subsidies have totaledadministration, the Global Nuclear Energy Partnership (GNEP)

  16. Nuclear Safety Research and Development...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Nuclear Safety Research and Development Proposal Review and Prioritization Process and Criteria Nuclear Safety Research and Development Program Office of Nuclear Safety Office of...

  17. NUCLEAR SCIENCE ANNUAL REPORT 1975

    E-Print Network [OSTI]

    Authors, Various

    2010-01-01T23:59:59.000Z

    Gove and A. H. Wapstra, Nuclear Data Tables 11, 127 (1972).P. Jackson, Chalk River Nuclear Laboratories Report (1975)national Conference on Nuclear Structure and Spec­ troscopy,

  18. China's Nuclear Industry After Fukushima

    E-Print Network [OSTI]

    YUAN, Jingdong

    2013-01-01T23:59:59.000Z

    the previous year. NUCLEAR TECHNOLOGY AND FUEL CYCLES China’third-generation nuclear technology and reactor design, withs own third-generation nuclear technology. Westing- house,

  19. NUCLEAR CHEMISTRY ANNUAL REPORT 1970

    E-Print Network [OSTI]

    Authors, Various

    2011-01-01T23:59:59.000Z

    Nuclear Laboratories, AECL, Chalk River, Ontario, Canada.Nuclear Laboratories, AECL, Chalk River, Ontario, Canada. 1.Nuclear Laboratories, AECL, Chalk River, Ontario, Canada. 1.

  20. Reactor & Nuclear Systems Publications | ORNL

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

    Science Home | Science & Discovery | Nuclear Science | Publications and Reports | Reactor and Nuclear Systems Publications SHARE Reactor and Nuclear Systems Publications The...

  1. Atomistic Simulation of Collision Cascades in Zircon. | EMSL

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

    regions occurs in the amorphous core. Citation: Devanathan R, LR Corrales, WJ Weber, A Chartier, and C Meis.2006."Atomistic Simulation of Collision Cascades in...

  2. Can CP violation be observed in heavy-ion collisions?

    SciTech Connect (OSTI)

    Khriplovich, I. B., E-mail: khriplovich@inp.nsk.su; Rudenko, A. S., E-mail: a.s.rudenko@inp.nsk.su [Budker Institute of Nuclear Physics (Russian Federation)

    2012-09-15T23:59:59.000Z

    We demonstrate that, at least at present, there is no convincing way to detect CP violation in heavy-ion collisions.

  3. A collision probability analysis of the double-heterogeneity problem

    SciTech Connect (OSTI)

    Hebert, A. (Commissariat a l'Energie Atomique, Yvette (France))

    1993-10-01T23:59:59.000Z

    A practical collision probability model is presented for the description of geometries with many levels of heterogeneity. Regular regions of the macrogeometry are assumed to contain a stochastic mixture of spherical grains or cylindrical tubes. Simple expressions for the collision probabilities in the global geometry are obtained as a function of the collision probabilities in the macro- and microgeometries. This model was successfully implemented in the collision probability kernel of the APOLLO-1, APOLLO-2, and DRAGON lattice codes for the description of a broad range of reactor physics problems. Resonance self-shielding and depletion calculations in the microgeometries are possible because each microregion is explicitly represented.

  4. High energy hadron-hadron collisions. [Dept. of Physics and Astronomy, Univ. of Georgia, Athens, Georgia

    SciTech Connect (OSTI)

    Chou, T.T.

    1992-01-01T23:59:59.000Z

    Results of a study on high energy collisions with the geometrical model are summarized in three parts: (1) the elastic hadron-hadron collision, (2) the inelastic hadron-hadron collision, and (3) e[sup +]e[sup [minus

  5. Working Group Report on - Space Nuclear Power Systems and Nuclear...

    Energy Savers [EERE]

    Working Group Report on - Space Nuclear Power Systems and Nuclear Waste Technology R&D Working Group Report on - Space Nuclear Power Systems and Nuclear Waste Technology R&D "Even...

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

    SciTech Connect (OSTI)

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

    2011-08-03T23:59:59.000Z

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

  7. 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.

  8. 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.

  9. B53 Nuclear Bomb Dismantlement | National Nuclear Security Administrat...

    National Nuclear Security Administration (NNSA)

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

  10. Assessment of Nuclear Resonance Fluorescence for Spent Nuclear Fuel Assay

    E-Print Network [OSTI]

    Quiter, Brian

    2012-01-01T23:59:59.000Z

    Spent Fuel Assay Using Nuclear Resonance Fluo- rescence,” Annual Meeting of the Institute of Nuclear Material Management,

  11. Assessment of Nuclear Resonance Fluorescence for Spent Nuclear Fuel Assay

    E-Print Network [OSTI]

    Quiter, Brian

    2012-01-01T23:59:59.000Z

    of the Institute of Nuclear Material Management, Tucson, AZ,Assay, Institute of Nuclear Materials Management 51st Annual

  12. Nuclear disarmament verification

    SciTech Connect (OSTI)

    DeVolpi, A.

    1993-12-31T23:59:59.000Z

    Arms control treaties, unilateral actions, and cooperative activities -- reflecting the defusing of East-West tensions -- are causing nuclear weapons to be disarmed and dismantled worldwide. In order to provide for future reductions and to build confidence in the permanency of this disarmament, verification procedures and technologies would play an important role. This paper outlines arms-control objectives, treaty organization, and actions that could be undertaken. For the purposes of this Workshop on Verification, nuclear disarmament has been divided into five topical subareas: Converting nuclear-weapons production complexes, Eliminating and monitoring nuclear-weapons delivery systems, Disabling and destroying nuclear warheads, Demilitarizing or non-military utilization of special nuclear materials, and Inhibiting nuclear arms in non-nuclear-weapons states. This paper concludes with an overview of potential methods for verification.

  13. Nuclear radiation actuated valve

    DOE Patents [OSTI]

    Christiansen, David W. (Kennewick, WA); Schively, Dixon P. (Richland, WA)

    1985-01-01T23:59:59.000Z

    A nuclear radiation actuated valve for a nuclear reactor. The valve has a valve first part (such as a valve rod with piston) and a valve second part (such as a valve tube surrounding the valve rod, with the valve tube having side slots surrounding the piston). Both valve parts have known nuclear radiation swelling characteristics. The valve's first part is positioned to receive nuclear radiation from the nuclear reactor's fuel region. The valve's second part is positioned so that its nuclear radiation induced swelling is different from that of the valve's first part. The valve's second part also is positioned so that the valve's first and second parts create a valve orifice which changes in size due to the different nuclear radiation caused swelling of the valve's first part compared to the valve's second part. The valve may be used in a nuclear reactor's core coolant system.

  14. Triangle Universities Nuclear Laboratory

    SciTech Connect (OSTI)

    Not Available

    1991-01-01T23:59:59.000Z

    This report contains brief papers that discusses the following topics: Fundamental Symmetries in the Nucleus; Internucleon Interactions; Dynamics of Very Light Nuclei; Facets of the Nuclear Many-Body Problem; and Nuclear Instruments and Methods.

  15. Promulgating Nuclear Safety Requirements

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

    1996-05-15T23:59:59.000Z

    Applies to all Nuclear Safety Requirements Adopted by the Department to Govern the Conduct of its Nuclear Activities. Cancels DOE P 410.1. Canceled by DOE N 251.85.

  16. NUCLEAR PLANT AND CONTROL

    E-Print Network [OSTI]

    NUCLEAR PLANT OPERATIONS AND CONTROL KEYWORDS: software require- ments, safety analysis, formal, the missiles, and the digital protection systems embed- ded in nuclear power plants. Obviously, safety method SOFTWARE SAFETY ANALYSIS OF DIGITAL PROTECTION SYSTEM REQUIREMENTS USING A QUALITATIVE FORMAL

  17. Hegemony and nuclear proliferation

    E-Print Network [OSTI]

    Miller, Nicholas L. (Nicholas LeSuer)

    2014-01-01T23:59:59.000Z

    Contrary to longstanding of predictions of nuclear tipping points, the number of states interested in nuclear weapons has sharply declined in recent decades. In contrast to existing explanations, this dissertation argues ...

  18. Nuclear Explosive Safety Manual

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

    2009-04-14T23:59:59.000Z

    This Manual provides supplemental details to support the requirements of DOE O 452.2D, Nuclear Explosive Safety.

  19. 3D NUCLEAR SEGMENTAT

    Energy Science and Technology Software Center (OSTI)

    003029WKSTN00 Delineation of nuclear structures in 3D multicellular systems  https://vision.lbl.gov/Software/3DMorphometry/ 

  20. Nuclear Nonproliferation Programs | ORNL

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

    Initiatives Nonproliferation Technology Nonproliferation Systems Safeguards and Security Technology International Safeguards Nuclear Material Detection and Characterization For...

  1. Nuclear Multifragmentation Critical Exponents

    E-Print Network [OSTI]

    Wolfgang Bauer; William Friedman

    1994-11-14T23:59:59.000Z

    We show that the critical exponents of nuclear multi-fragmentation have not been determined conclusively yet.

  2. Descriptions of Motor Vehicle Collisions by Participants in Emergency Department–Based Studies: Are They Accurate?

    E-Print Network [OSTI]

    2012-01-01T23:59:59.000Z

    reports in determining motor vehicle crash characteristics.R ESEARCH Descriptions of Motor Vehicle Collisions byThe immediate aftermath of motor vehicle collisions. In:

  3. Nuclear Energy Research Brookhaven National

    E-Print Network [OSTI]

    Ohta, Shigemi

    Nuclear Energy Research Brookhaven National Laboratory William C. Horak, Chair Nuclear Science and Technology Department #12;BNL Nuclear Energy Research Brookhaven Graphite Research Reactor - 1948 National Nuclear Data Center - 1952* High Flux Beam Reactor - 1964 Technical Support for NRC - 1974

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

    E-Print Network [OSTI]

    M. J. Tannenbaum

    2006-07-28T23:59:59.000Z

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

  5. NUCLEAR POWER in CALIFORNIA

    E-Print Network [OSTI]

    NUCLEAR POWER in CALIFORNIA: 2007 STATUS REPORT CALIFORNIA ENERGY COMMISSION October 2007 CEC-100, California Contract No. 700-05-002 Prepared For: California Energy Commission Barbara Byron, Senior Nuclear public workshops on nuclear power. The Integrated Energy Policy Report Committee, led by Commissioners

  6. Nuclear fact book

    SciTech Connect (OSTI)

    Hill, O.F.; Platt, A.M.; Robinson, J.V.

    1983-05-01T23:59:59.000Z

    This reference provides significant highlights and summary facts in the following areas: general energy; nuclear energy; nuclear fuel cycle; uranium supply and enrichment; nuclear reactors; spent fuel and advanced repacking concepts; reprocessing; high-level waste; gaseous waste; transuranic waste; low-level waste; remedial action; transportation; disposal; radiation information; environment; legislation; socio-political aspects; conversion factors; and a glossary. (GHT)

  7. NUCLEAR PLANT OPERATIONS AND

    E-Print Network [OSTI]

    Demazičre, Christophe

    NUCLEAR PLANT OPERATIONS AND CONTROL KEYWORDS: moderator temper ature coefficient, reactivity co reactor Unit 4 of the Ringhals Nuclear Power Plant (Sweden) during fuel cycle 16 is analyzed absorption cross-section behavior. Consequently, if NUCLEAR TECHNOLOGY VOL. 140 NOV. 2002 147 #12;Demazičre

  8. NUCLEAR PLANT OPERATIONS AND

    E-Print Network [OSTI]

    Pázsit, Imre

    NUCLEAR PLANT OPERATIONS AND CONTROL KEYWORDS: moderator temper- ature coefficient, reactivity co reactor Unit 4 of the Ringhals Nuclear Power Plant (Sweden) during fuel cycle 16 is analyzed. Consequently, if*E-mail: demaz@nephy.chalmers.se NUCLEAR TECHNOLOGY VOL. 140 NOV. 2002 147 #12;high-burnup fuel

  9. Nuclear Explosive Safety

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

    2009-04-14T23:59:59.000Z

    This Order establishes requirements to implement the nuclear explosive safety elements of DOE O 452.1D, Nuclear Explosive and Weapon Surety Program, for routine and planned nuclear explosive operations. Cancels DOE O 452.2C. Admin Chg 1, 7-10-13

  10. Nuclear Explosive Safety

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

    2009-04-14T23:59:59.000Z

    This Department of Energy (DOE) Order establishes requirements to implement the nuclear explosive safety (NES) elements of DOE O 452.1D, Nuclear Explosive and Weapon Surety Program, for routine and planned nuclear explosive operations (NEOs). Cancels DOE O 452.2C. Admin Chg 1, dated 7-10-13, cancels DOE O 452.2D.

  11. Nuclear & Particle Physics, Astrophysics, Cosmology

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

    Nuclear & Particle Physics science-innovationassetsimagesicon-science.jpg Nuclear & Particle Physics, Astrophysics, Cosmology National security depends on science and...

  12. Is Nuclear Energy the Solution?

    E-Print Network [OSTI]

    Saier, Milton H.; Trevors, Jack T.

    2010-01-01T23:59:59.000Z

    the potential of nuclear power to combat global warming havecompetitive today, and for nuclear power to succeed, it must

  13. Sideward Flow in Au + Au Collisions Between 2A GeV and 8A GeV

    E-Print Network [OSTI]

    E895 Collaboration; H. Liu; N. N. Ajitanand; J. Alexander; M. Anderson; D. Best; F. P. Brady; T. Case; W. Caskey; D. Cebra; J. Chance; B. Cole; K. Crowe; A. Das; J. Draper; M. Gilkes; S. Gushue; M. Heffner; A. Hirsch; E. Hjort; L. Huo; M. Justice; M. Kaplan; D. Keane; J. Kintner; J. Klay; D. Krofcheck; R. Lacey; M. A. Lisa; Y. M. Liu; R. McGrath; Z. Milosevich; G. Odyniec; D. Olson; S. Y. Panitkin; N. Porile; G. Rai; H. G. Ritter; J. Romero; R. Scharenberg; L. S. Schroeder; B. Srivastava; N. T. B. Stone; T. J. M. Symons; S. Wang; J. Whitfield; T. Wienold; R. Witt; L. Wood; X. Yang; W. N. Zhang; Y. Zhang

    2000-05-24T23:59:59.000Z

    Using the large acceptance Time Projection Chamber of experiment E895 at Brookhaven, measurements of collective sideward flow in Au + Au collisions at beam energies of 2, 4, 6 and 8A GeV are presented in the form of in-plane transverse momentum and the first Fourier coefficient of azimuthal anisotropy v_1. These measurements indicate a smooth variation of sideward flow as a function of beam energy. The data are compared with four nuclear transport models which have an orientation towards this energy range. All four exhibit some qualitative trends similar to those found in the data, although none shows a consistent pattern of agreement within experimental uncertainties.

  14. Multiverse rate equation including bubble collisions

    E-Print Network [OSTI]

    Michael P. Salem

    2013-02-19T23:59:59.000Z

    The volume fractions of vacua in an eternally inflating multiverse are described by a coarse-grain rate equation, which accounts for volume expansion and vacuum transitions via bubble formation. We generalize the rate equation to account for bubble collisions, including the possibility of classical transitions. Classical transitions can modify the details of the hierarchical structure among the volume fractions, with potential implications for the staggering and Boltzmann-brain issues. Whether or not our vacuum is likely to have been established by a classical transition depends on the detailed relationships among transition rates in the landscape.

  15. Upsilon Production In p-p Collisions at LHC

    E-Print Network [OSTI]

    Leonard S. Kisslinger

    2012-02-17T23:59:59.000Z

    This is a continuation of recent studies of $\\Upsilon(nS)$ production at the LHC in p-p collisions. Our previous studies were for 2.76 TeV, while the present predictions are for 7.0 TeV collisions.

  16. The noncommutative QED threshold energy versus the optimum collision energy

    E-Print Network [OSTI]

    Zheng-Mao Sheng; Yongming Fu; Haibo Yu

    2004-02-10T23:59:59.000Z

    Moller Scattering and Bhabha Scattering on noncommutative space-time is restudied. It is shown that the noncommutative correction of scattering cross sections is not monotonous enhancement with the total energy of colliding electrons, there is an optimum collision energy to get the greatest noncommutative correction. Most surprisingly, there is a linear relation between the noncommutative QED threshold energy and the optimum collision energy.

  17. Deuteron-nucleus collisions in a multiphase transport model

    E-Print Network [OSTI]

    Lin, ZW; Ko, Che Ming.

    2003-01-01T23:59:59.000Z

    of protons more than those of kaons or pions. Relative to p+p collisions at same center-of-mass energy per nucleon pair, the effect of final-state interactions on the charged particle transverse momentum spectra in d+Au collisions is much smaller than...

  18. What Is the Use of Collision Detection (in Wireless Networks)?

    E-Print Network [OSTI]

    What Is the Use of Collision Detection (in Wireless Networks)? Johannes Schneider1 , Roger.g. there is energy on the channel in a wireless network. This model is called the collision detection model. Furthermore, many algorithms for wireless networks are designed for gen- eral graphs. This model does

  19. ENERGY BASED ICE COLLISION FORCES Claude Daley1

    E-Print Network [OSTI]

    Daley, Claude

    1 ENERGY BASED ICE COLLISION FORCES Claude Daley1 1 Memorial University of Newfoundland, St. John's, Newfoundland, Canada A1C 3X5 ABSTRACT Ice collision forces can be determined by energy considerations. A variety of interaction geometry cases are considered. The indentation energy functions for eight different

  20. ENERGY BASED ICE COLLISION FORCES Claude Daley1

    E-Print Network [OSTI]

    Daley, Claude

    ENERGY BASED ICE COLLISION FORCES Claude Daley1 1 Memorial University of Newfoundland, St. John's, Newfoundland, Canada A1C 3X5 ABSTRACT Ice collision forces can be determined by energy considerations. A variety of interaction geometry cases are considered. The indentation energy functions for eight different

  1. Temperature Dependence of Stark Broadening Dominated by Strong Collisions

    SciTech Connect (OSTI)

    Gigosos, M. A. [Departamento de Optica, Universidad de Valladolid. 47071 Valladolid (Spain) (Spain); Gonzalez, M. A. [Departamento de Fisica Aplicada, Universidad de Valladolid. 47071 Valladolid (Spain); Konjevic, N. [Institute of Physics, P.O. box 68, 11081 Belgrade (Serbia and Montenegro)

    2006-11-22T23:59:59.000Z

    The influence of electron temperature in the broadening of spectral lines dominated by strong collisions has been studied. Computer simulation allows us to study the effects of strong and weak collisions separately. Results shown here are focused on some Sr+ and Ba+ resonance lines as examples of lines broadened dominantly by strong collisions. The exact numerical integration of the perturbation process due to the collision with a single particle permits the evaluation of Weisskopf radius. This parameter is usually defined as rw {approx} 1/v {approx} 1/{radical}T, obtained from Bora approximation that is correct for high temperatures. However, at low temperatures the full integration of the collision process permits to test the relationship rw {approx} 1/T1/6. This calculation has allowed us to study the influence of temperature on the broadening of the lines dominated by strong collisions. This study has been done in two ways : through a plasma simulation and analyzing the calculated Weisskopf radius for an individual collision. The obtained results show that at low temperatures the width of the line increases for increasing temperature as a consequence of an increase of the number of collisions not compensated by the decrease of Weisskopf radius.

  2. Onset of radial flow in p+p collisions

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

    Jiang, Kun; Zhu, Yinying; Liu, Weitao; Chen, Hongfang; Li, Cheng; Ruan, Lijuan; Tang, Zebo; Xu, Zhangbu

    2015-02-01T23:59:59.000Z

    It has been debated for decades whether hadrons emerging from p+p collisions exhibit collective expansion. The signal of the collective motion in p+p collisions is not as clear as in heavy-ion collisions because of the low multiplicity and large fluctuation in p+p collisions. Tsallis Blast-Wave (TBW) model is a thermodynamic approach, introduced to handle the overwhelming correlation and fluctuation in the hadronic processes. We have systematically studied the identified particle spectra in p+p collisions from RHIC to LHC using TBW and found no appreciable radial flow in p+p collisions below ?s = 900 GeV. At LHC higher energy of 7more »TeV in p+p collisions, the radial flow velocity achieves an average of (?) = 0.320 ± 0.005. This flow velocity is comparable to that in peripheral (40-60%) Au+Au collisions at RHIC. Breaking of the identified particle spectra mT scaling was also observed at LHC from a model independent test.« less

  3. Jet production in ep collisions Pierre Van Mechelen

    E-Print Network [OSTI]

    Jet production in ep collisions Pierre Van Mechelen University of Antwerpen Pierre Outline: Introduction Inclusive jet photoproduction Dijet electroproduction Inclusve jet electroproduction #12; Jet production in ep collisions Pierre Van Mechelen HERA, H1 and ZEUS H1 ZEUS p (920 GeV) e

  4. Onset of radial flow in p+p collisions

    E-Print Network [OSTI]

    Kun Jiang; Yinying Zhu; Weitao Liu; Hongfang Chen; Cheng Li; Lijuan Ruan; Ming Shao; Zebo Tang; Zhangbu Xu

    2014-12-23T23:59:59.000Z

    It has been debated for decades whether hadrons emerging from p+p collisions exhibit collective expansion. The signal of the collective motion in p+p collisions is not as clear/clean as in heavy-ion collisions because of the low multiplicity and large fluctuation in p+p collisions. Tsallis Blast-Wave (TBW) model is a thermodynamic approach, introduced to handle the overwhelming correlation and fluctuation in the hadronic processes. We have systematically studied the identified particle spectra in p+p collisions from RHIC to LHC using TBW and found no appreciable radial flow in p+p collisions below $\\sqrt{s}=900$ GeV. At LHC higher energy of 7 TeV in p+p collisions, the radial flow velocity achieves an average value of $= 0.320\\pm0.005$. This flow velocity is comparable to that in peripheral (40-60%) Au+Au collisions at RHIC. Breaking of the identified particle spectra $m_T$ scaling was also observed at LHC from a model independent test.

  5. Sensorless Robot Collision Detection and Hybrid Force/Motion Control

    E-Print Network [OSTI]

    De Luca, Alessandro

    a lightweight robot design [6], possibly with distributed compliant characteristics in the driving system andSensorless Robot Collision Detection and Hybrid Force/Motion Control Alessandro De Luca Raffaella-time detection of collisions between a robot manipulator and obstacles of unknown geometry and location

  6. Rotation as an origin of high energy particle collisions

    E-Print Network [OSTI]

    Zaslavskii, O B

    2015-01-01T23:59:59.000Z

    We consider collision of two particles in rotating spacetimes without horizons. If the metric coefficient responsible for rotation of spacetime is big enough in some region, the energy of collisions in the centre of mass frame can be as large as one likes. The results are model-independent and apply both to relativistic stars and wormholes.

  7. Nuclear spirals in galaxies

    E-Print Network [OSTI]

    Witold Maciejewski

    2006-11-08T23:59:59.000Z

    Recent high-resolution observations indicate that nuclear spirals are often present in the innermost few hundred parsecs of disc galaxies. My models show that nuclear spirals form naturally as a gas response to non-axisymmetry in the gravitational potential. Some nuclear spirals take the form of spiral shocks, resulting in streaming motions in the gas, and in inflow comparable to the accretion rates needed to power local Active Galactic Nuclei. Recently streaming motions of amplitude expected from the models have been observed in nuclear spirals, confirming the role of nuclear spirals in feeding of the central massive black holes.

  8. Evidence for color fluctuations in hadrons from coherent nuclear diffraction

    SciTech Connect (OSTI)

    Frankfurt, L. (Tel Aviv University, Ramat Aviv (Israel)); Miller, G.A. (Department of Physcis, FM-15, University of Washington, Seattle, Washington 98195 (United States)); Strikman, M. (Department of Physcis, Pennsylvania State University, University Park, Pennsylvania 16801 (United States))

    1993-11-01T23:59:59.000Z

    A QCD-based treatment of projectile size fluctuations is used to compute inelastic diffractive cross sections [sigma][sub diff] for coherent hadron-nuclear processes. We find that fluctuations near the average size give the major contribution to the cross section with [lt] few % contribution from small size configurations. The computed values of [sigma][sub diff] are consistent with the limited available data. The importance of coherent diffraction studies for a wide range of projectiles for high energy Fermilab fixed target experiments is emphasized. The implications of these significant color fluctuations for relativistic heavy ion collisions are discussed.

  9. Three-body collisions in Boltzmann-Uehling-Uhlenbeck theory

    SciTech Connect (OSTI)

    Larionov, A. B. [Institut fuer Theoretische Physik, Universitaet Giessen, D-35392 Giessen (Germany); Frankfurt Institute for Advanced Studies, J. W. Goethe-Universitaet, D-60438 Frankfurt am Main (Germany); Russian Research Center Kurchatov Institute, RU-123182 Moscow (Russian Federation); Buss, O.; Gallmeister, K.; Mosel, U. [Institut fuer Theoretische Physik, Universitaet Giessen, D-35392 Giessen (Germany)

    2007-10-15T23:59:59.000Z

    Aiming at a microscopic description of heavy ion collisions in the beam energy region of about 10A GeV, we extend the Giessen Boltzmann-Uehling-Uhlenbeck (GiBUU) transport model by including a relativistic mean field, in-medium baryon-baryon cross sections, and three-body collisions. The model is then compared with experimental data for central Au+Au collisions at 2A-10A GeV and central Pb+Pb collisions at 30A and 40A GeV on the proton rapidity spectra, the midrapidity yields of {pi}{sup +},K{sup {+-}}, and ({lambda}+{sigma}{sup 0}), and the transverse mass spectra of {pi}{sup {+-}} and K{sup {+-}}. The three-body collisions increase the inverse slope parameters of the hadron m{sub perpendicular} spectra to good agreement with the data.

  10. Commercial nuclear power 1990

    SciTech Connect (OSTI)

    Not Available

    1990-09-28T23:59:59.000Z

    This report presents the status at the end of 1989 and the outlook for commercial nuclear capacity and generation for all countries in the world with free market economies (FME). The report provides documentation of the US nuclear capacity and generation projections through 2030. The long-term projections of US nuclear capacity and generation are provided to the US Department of Energy's (DOE) Office of Civilian Radioactive Waste Management (OCRWM) for use in estimating nuclear waste fund revenues and to aid in planning the disposal of nuclear waste. These projections also support the Energy Information Administration's annual report, Domestic Uranium Mining and Milling Industry: Viability Assessment, and are provided to the Organization for Economic Cooperation and Development. The foreign nuclear capacity projections are used by the DOE uranium enrichment program in assessing potential markets for future enrichment contracts. The two major sections of this report discuss US and foreign commercial nuclear power. The US section (Chapters 2 and 3) deals with (1) the status of nuclear power as of the end of 1989; (2) projections of nuclear capacity and generation at 5-year intervals from 1990 through 2030; and (3) a discussion of institutional and technical issues that affect nuclear power. The nuclear capacity projections are discussed in terms of two projection periods: the intermediate term through 2010 and the long term through 2030. A No New Orders case is presented for each of the projection periods, as well as Lower Reference and Upper Reference cases. 5 figs., 30 tabs.

  11. Experimental effects on dynamics and thermodynamics in nuclear reactions on the symmetry energy as seen by the CHIMERA 4$?$ detector

    E-Print Network [OSTI]

    E. De Filippo; A. Pagano

    2013-10-22T23:59:59.000Z

    Heavy ion collisions have been widely used in the last decade to constraint the parameterizations of the symmetry energy term of nuclear equation of state (EOS) for asymmetric nuclear matter as a function of baryonic density. In the Fermi energy domain one is faced with variations of the density within a narrow range of values around the saturation density $\\rho_0$=0.16 fm$^{-3}$ down towards sub-saturation densities. The experimental observables which are sensitive to the symmetry energy are constructed starting from the detected light particles, clusters and heavy fragments that, in heavy ion collisions, are generally produced by different emission mechanisms at different stages and time scales of the reaction. In this review the effects of dynamics and thermodynamics on the symmetry energy in nuclear reactions are discussed and characterized using an overview of the data taken so far with the CHIMERA multi-detector array.

  12. Temperature dependence of single-particle properties in nuclear and neutron matter in the Dirac-Brueckner-Hartree-Fock model

    E-Print Network [OSTI]

    Francesca Sammarruca

    2009-08-13T23:59:59.000Z

    The understanding of the interaction of nucleons in nuclear and neutron-rich matter at non-zero temperature is important for a variety of applications ranging from heavy-ion collisions to nuclear astrophysics. In this paper we apply the Dirac-Brueckner-Hartree-Fock method along with the Bonn B nucleon-nucleon potential to predict single-particle properties in symmetric nuclear matter and pure neutron matter at finite temperature. It is found that temperature effects are generally small but can be significant at low density and momentum.

  13. Isospin aspects in nuclear reactions involving Ca beams at 25 MeV/nucleon

    SciTech Connect (OSTI)

    Lombardo, I., E-mail: ilombardo@lns.infn.it; Agodi, C.; Alba, R.; Amorini, F.; Anzalone, A. [INFN Laboratori Nazionali del Sud (Italy); Auditore, L. [Universita di Messina, and INFN-Gr. Coll. Messina, Dipartimento di Fisica (Italy); Berceanu, I. [Institute for Physics and Nuclear Engineering (Romania); Cardella, G. [INFN, Sezione di Catania (Italy); Cavallaro, S. [INFN Laboratori Nazionali del Sud (Italy); Chatterjee, M. B. [Saha Institute of Nuclear Physics (India); Filippo, E. De [INFN, Sezione di Catania (Italy); Di Pietro, A.; Figuera, P. [INFN Laboratori Nazionali del Sud (Italy); Giuliani, G.; Geraci, E.; Grassi, L. [Dipartimento di Fisica e Astronomia Universita di Catania (Italy); Grzeszczuk, A. [University of Silesia, Institute of Physics (Poland); Han, J. [INFN Laboratori Nazionali del Sud (Italy); La Guidara, E. [INFN, Sezione di Catania (Italy); Lanzalone, G. [INFN Laboratori Nazionali del Sud (Italy); and others

    2011-11-15T23:59:59.000Z

    Isospin dependence of dynamical and thermodynamical properties observed in reactions {sup 40}Ca+ {sup 40,48}Ca and {sup 40}Ca + {sup 46}Ti at 25 MeV/nucleon has been studied. We used the CHIMERA multi-detector array. Strong isospin effects are seen in the isotopic distributions of light nuclei and in the competition between different reaction mechanisms in semi-central collisions. We will show also preliminary results obtained in nuclear collision {sup 48}Ca + {sup 48}Ca at 25MeV/nucleon, having very high N/Z value in the entrance channel (N/Z = 1.4). The enhancement of evaporation residue production confirms the strong role played by the N/Z degree of freedom in nuclear dynamics.

  14. Interplay Of Mean Field And Individual Nucleon Collisions Effects At Intermediate Energy Heavy Ion Reactions

    SciTech Connect (OSTI)

    Subotic, K.; Jordanov, D.; Durasevic, M.; Dragosavac, D. [VINCA Institute of Nuclear Sciences, P.O. Box 522, 11001 Belgrade (Serbia and Montenegro); Grabez, B. [Institute of Physics, P.O. Box 57, 11080 Belgrade (Serbia and Montenegro)

    2007-04-23T23:59:59.000Z

    In our study of the reaction 20Ne+27Al at energy of 84 A MeV, the track detectors were used to select the target like fragments arising from processes in which the interacting system becomes disintegrated into a large number of constituent nucleons and one massive fragment. Heavy ion reaction studies at bombarding energies of several tens of MeV/nucleon have provided the evidence that most of reaction cross section, in this energy range, is associated with the production of primary projectile like and target like fragment in the first step of the nuclear reaction. The subsequent evolution of the studied reaction systems, has been usually described either using low energy models based on mean field effects (MFE), or high energy models where reaction proceeds by independent collisions (INC) of individual nucleons in the overlap region between target and projectile. The analysis of our results in terms of different MFE and INC models, prescribing consistent timings, has shown that the reaction mechanism may be defined of interplay of the mean field and individual nucleon collisions effects.

  15. Conical Emission from Shock Waves in Ne(1-20 AGeV)+U Collisions

    E-Print Network [OSTI]

    Philip Rau; Jan Steinheimer; Barbara Betz; Hannah Petersen; Marcus Bleicher; Horst Stöcker

    2010-03-05T23:59:59.000Z

    The formation and propagation of high-density compression waves, e.g. Mach shock waves, in cold nuclear matter is studied by simulating high-energy nucleus-nucleus collisions of Ne with U in the energy range from E_lab = 0.5 AGeV to 20 AGeV. In an ideal hydrodynamic approach, the high-density shock wave created by the small Ne nucleus passing through the heavy U nucleus is followed by a slower and more dilute Mach shock wave which causes conical emission of particles at the Mach cone angle. The conical emission originates from low-density regions with a small flow velocity comparable to the speed of sound. Moreover, it is shown that the angular distributions of emitted baryons clearly distinguish between a hydrodynamic approach and binary cascade processes used in the Ultra-relativistic Quantum Molecular Dynamics (UrQMD) transport model.

  16. Elliptic flow and energy loss of heavy quarks in ultra-relativistic heavy ion collisions

    E-Print Network [OSTI]

    Jan Uphoff; Oliver Fochler; Zhe Xu; Carsten Greiner

    2011-08-24T23:59:59.000Z

    The space-time propagation of heavy quarks in ultra-relativistic heavy ion collisions is studied within the partonic transport model Boltzmann Approach of MultiParton Scatterings (BAMPS). In this model heavy quarks interact with the partonic medium via binary scatterings. The cross sections for these interactions are calculated with leading order perturbative QCD, but feature a more precise Debye screening derived within the hard thermal loop approximation and obey the running of the coupling. Within this framework the elliptic flow and the nuclear modification factor of heavy quarks are computed for RHIC and LHC energies and compared to available experimental data. It is found that binary scatterings alone cannot reproduce the data and, therefore, radiative corrections have to be taken into account.

  17. Elliptic flow and energy loss of heavy quarks in ultrarelativistic heavy ion collisions

    SciTech Connect (OSTI)

    Uphoff, Jan; Fochler, Oliver; Greiner, Carsten [Institut fuer Theoretische Physik, Johann Wolfgang Goethe-Universitaet Frankfurt, Max-von-Laue-Strasse 1, D-60438 Frankfurt am Main (Germany); Xu, Zhe [Institut fuer Theoretische Physik, Johann Wolfgang Goethe-Universitaet Frankfurt, Max-von-Laue-Strasse 1, D-60438 Frankfurt am Main (Germany); Frankfurt Institute for Advanced Studies, Ruth-Moufang-Strasse 1, D-60438 Frankfurt am Main (Germany)

    2011-08-15T23:59:59.000Z

    The space-time propagation of heavy quarks in ultrarelativistic heavy ion collisions is studied within the partonic transport model Boltzmann approach of multiparton scatterings (BAMPS). In this model heavy quarks interact with the partonic medium via binary scatterings. The cross sections for these interactions are calculated with leading-order perturbative QCD, but feature a more precise Debye screening derived within the hard thermal loop approximation and obey the running of the coupling. Within this framework the elliptic flow and the nuclear modification factor of heavy quarks are computed for the BNL Relativistic Heavy Ion Collider (RHIC) and the CERN Large Hadron Collider (LHC) energies and compared to available experimental data. It is found that binary scatterings alone cannot reproduce the data and therefore radiative corrections have to be taken into account.

  18. Partonic flow and $?$-meson production in Au+Au collisions at $\\sqrt{s_{NN}}$ = 200 GeV

    E-Print Network [OSTI]

    B. I. Abelev

    2007-03-20T23:59:59.000Z

    We present first measurements of the $\\phi$-meson elliptic flow ($v_{2}(p_{T})$) and high statistics $p_{T}$ distributions for different centralities from $\\sqrt{s_{NN}}$ = 200 GeV Au+Au collisions at RHIC. In minimum bias collisions the $v_{2}$ of the $\\phi$ meson is consistent with the trend observed for mesons. The ratio of the yields of the $\\Omega$ to those of the $\\phi$ as a function of transverse momentum is consistent with a model based on the recombination of thermal $s$ quarks up to $p_{T}\\sim 4$ GeV/$c$, but disagrees at higher momenta. The nuclear modification factor ($R_{CP}$) of $\\phi$ follows the trend observed in the $K^{0}_{S}$ mesons rather than in $\\Lambda$ baryons, supporting baryon-meson scaling. Since $\\phi$-mesons are made via coalescence of seemingly thermalized $s$ quarks in central Au+Au collisions, the observations imply hot and dense matter with partonic collectivity has been formed at RHIC.

  19. Nuclear facilities: criteria for the design and operation of ventilation systems for nuclear installations other than nuclear reactors

    E-Print Network [OSTI]

    International Organization for Standardization. Geneva

    2004-01-01T23:59:59.000Z

    Nuclear facilities: criteria for the design and operation of ventilation systems for nuclear installations other than nuclear reactors

  20. Energy loss and $x_2$ scaling breakdown in $J/?$ nuclear production

    E-Print Network [OSTI]

    F. Arleo; P. -B. Gossiaux; T. Gousset; J. Aichelin

    2000-05-23T23:59:59.000Z

    In addition to the final-state interactions, $J/\\psi$ nuclear production might also be affected by parton energy loss. Using the upper limits from Drell-Yan data at SPS and Fermilab energies, we estimated energy loss contribution to $J/\\psi$ production in p-A collisions. The results indicated that the effects might be sizeable at 200 GeV while remaining small at higher energies.

  1. Pumice-pumice collisions and the effect of the impact angle B. Cagnoli and M. Manga

    E-Print Network [OSTI]

    Manga, Michael

    , 1997]. Collisions are important also in dense gas-fluidised beds, where the hydrodynamics is strongly

  2. Comparison of Coulomb Collision Rates in the Plasma Physics and Magnetically Confined Fusion Literature

    E-Print Network [OSTI]

    Comparison of Coulomb Collision Rates in the Plasma Physics and Magnetically Confined Fusion Literature

  3. Supplemental Material for the SIGGRAPH 2005 Poster "The Expected Running Time of Hierarchical Collision

    E-Print Network [OSTI]

    Zachmann, Gabriel

    Collision Detection" Jan Klein University of Paderborn Gabriel Zachmann Clausthal University Figure 1

  4. Stochastic Optimization for Collision Selection in High Energy Physics

    E-Print Network [OSTI]

    S. Whiteson; D. Whiteson

    2006-07-10T23:59:59.000Z

    The underlying structure of matter can be deeply probed via precision measurements of the mass of the \\emph{top quark}, the most massive observed fundamental particle. Top quarks can be produced and studied only in collisions at high energy particle accelerators. Most collisions, however, do not produce top quarks; making precise measurements requires culling these collisions into a sample that is rich in collisions producing top quarks (\\emph{signal}) and spare in collisions producing other particles (\\emph{background}). Collision selection is typically performed with heuristics or supervised learning methods. However, such approaches are suboptimal because they assume that the selector with the highest classification accuracy will yield a mass measurement with the smallest statistical uncertainty. In practice, however, the mass measurement is more sensitive to some backgrounds than others. Hence, this paper presents a new approach that uses stochastic optimization techniques to directly search for selectors that minimize statistical uncertainty in the top quark mass measurement. Empirical results confirm that stochastically optimized selectors have much smaller uncertainty. This new approach contributes substantially to our knowledge of the top quark's mass, as the new selectors are currently in use selecting real collisions.

  5. Oregon State University nuclear chemistry progress report, August 1, 1992--July 1, 1993

    SciTech Connect (OSTI)

    Loveland, W.

    1993-07-01T23:59:59.000Z

    This report discusses the following topics related to nuclear chemistry: Element 110; synthesis of heavy nuclei with complete fusion reactions involving radioactive nuclear beams; the interaction of 21--44 MeV/nucleon Xe with Au; MeV/nucleon {sup 86}Kr with {sup 197}Au; intermediate energy Ar-Th collisions; target-like fragments from the interaction of 29 MeV/nucleon {sup 208}Pb with {sup 197}Au; the intermediate of 22 and 32 MeV/nucleon {sup 16}O with {sup 197}Au; Au projectile fragmentation at 20 MeV/nucleon; relativistic heavy ion research; and pulse height defect measurements for very heavy ions.

  6. Experimental Determination of In-Medium Cluster Binding Energies and Mott Points in Nuclear Matter

    E-Print Network [OSTI]

    K. Hagel; R. Wada; L. Qin; J. B. Natowitz; S. Shlomo; A. Bonasera; G. Röpke; S. Typel; Z. Chen; M. Huang; J. Wang; H. Zheng; S. Kowalski; C. Bottosso; M. Barbui; M. R. D. Rodrigues; K. Schmidt; D. Fabris; M. Lunardon; S. Moretto; G. Nebbia; S. Pesente; V. Rizzi; G. Viesti; M. Cinausero; G. Prete; T. Keutgen; Y. El Masri; Z. Majka

    2012-03-20T23:59:59.000Z

    In medium binding energies and Mott points for $d$, $t$, $^3$He and $\\alpha$ clusters in low density nuclear matter have been determined at specific combinations of temperature and density in low density nuclear matter produced in collisions of 47$A$ MeV $^{40}$Ar and $^{64}$Zn projectiles with $^{112}$Sn and $^{124}$Sn target nuclei. The experimentally derived values of the in medium modified binding energies are in good agreement with recent theoretical predictions based upon the implementation of Pauli blocking effects in a quantum statistical approach.

  7. Theory of Coherent and Incoherent Nuclear Spin-Dephasing in the Heart

    E-Print Network [OSTI]

    Wolfgang R. Bauer; Walter Nadler; Michael Bock; Lothar R. Schad; Christian Wacker; Andreas Hartlep; Georg Ertl

    1999-10-01T23:59:59.000Z

    We present an analytical theory of susceptibility induced nuclear spin dephasing in the capillary network of myocardium. Using a strong collision approach, equations are obtained for the relaxation rate of the free induction and the spin echo decay. Simulation and experimental data are well predicted by the theory. Since paramagnetic deoxyhemoglobin as the origin of nuclear spin dephasing has a higher tissue concentration in myocardium supplied by a stenotic, i. e. significantly narrowed, coronary artery, spin dephasing might serve as a diagnostic tool. Our approach can be modified for capillary networks in other tissues than myocardium and may be applied in material science.

  8. Coherent Nuclear Radiation

    E-Print Network [OSTI]

    V. I. Yukalov; E. P. Yukalova

    2004-06-22T23:59:59.000Z

    The main part of this review is devoted to the comprehensive description of coherent radiation by nuclear spins. The theory of nuclear spin superradiance is developed and the experimental observations of this phenomenon are considered. The intriguing problem of how coherence develops from initially incoherent quantum fluctuations is analysed. All main types of coherent radiation by nuclear spins are discussed, which are: free nuclear induction, collective induction, maser generation, pure superradiance, triggered superradiance, pulsing superradiance, punctuated superradiance, and induced emission. The influence of electron-nuclear hyperfine interactions and the role of magnetic anisotropy are studied. Conditions for realizing spin superradiance by magnetic molecules are investigated. The possibility of nuclear matter lasing, accompanied by pion or dibaryon radiation, is briefly touched.

  9. Instrumentation for Nuclear Applications

    SciTech Connect (OSTI)

    NONE

    1998-09-18T23:59:59.000Z

    The objective of this project was to develop and coordinate nuclear instrumentation standards with resulting economies for the nuclear and radiation fields. There was particular emphasis on coordination and management of the Nuclear Instrument Module (NIM) System, U.S. activity involving the CAMAC international standard dataway system, the FASTBUS modular high-speed data acquisition and control system and processing and management of national nuclear instrumentation and detector standards, as well as a modest amount of assistance and consultation services to the Pollutant Characterization and Safety Research Division of the Office of Health and Environmental Research. The principal accomplishments were the development and maintenance of the NIM instrumentation system that is the predominant instrumentation system in the nuclear and radiation fields worldwide, the CAMAC digital interface system in coordination with the ESONE Committee of European Laboratories, the FASTBUS high-speed system and numerous national and international nuclear instrumentation standards.

  10. Nuclear Science References Database

    E-Print Network [OSTI]

    B. Pritychenko; E. B?ták; B. Singh; J. Totans

    2014-07-08T23:59:59.000Z

    The Nuclear Science References (NSR) database together with its associated Web interface, is the world's only comprehensive source of easily accessible low- and intermediate-energy nuclear physics bibliographic information for more than 210,000 articles since the beginning of nuclear science. The weekly-updated NSR database provides essential support for nuclear data evaluation, compilation and research activities. The principles of the database and Web application development and maintenance are described. Examples of nuclear structure, reaction and decay applications are specifically included. The complete NSR database is freely available at the websites of the National Nuclear Data Center http://www.nndc.bnl.gov/nsr and the International Atomic Energy Agency http://www-nds.iaea.org/nsr.

  11. Scintillation Response of Liquid Xenon to Low Energy Nuclear Recoils

    E-Print Network [OSTI]

    E. Aprile; K. L. Giboni; P. Majewski; K. Ni; M. Yamashita; R. Hasty; A. Manzur; D. N. McKinsey

    2005-03-29T23:59:59.000Z

    Liquid Xenon (LXe) is expected to be an excellent target and detector medium to search for dark matter in the form of Weakly Interacting Massive Particles (WIMPs). Knowledge of LXe ionization and scintillation response to low energy nuclear recoils expected from the scattering of WIMPs by Xe nuclei is important for determining the sensitivity of LXe direct detection experiments. Here we report on new measurements of the scintillation yield of Xe recoils with kinetic energy as low as 10 keV. The dependence of the scintillation yield on applied electric field was also measured in the range of 0 to 4 kV/cm. Results are in good agreement with recent theoretical predictions that take into account the effect of biexcitonic collisions in addition to the nuclear quenching effect.

  12. A High Energy Nuclear Database Proposal

    E-Print Network [OSTI]

    David A. Brown; Ramona Vogt

    2005-10-13T23:59:59.000Z

    We propose to develop a high-energy heavy-ion experimental database and make it accessible to the scientific community through an on-line interace. This database will be searchable and cross-indexed with relevant publications, including published detector descriptions. Since this database will be a community resource, it requires the high-energy nuclear physics community's financial and manpower support. This database should eventually contain all published data from the Bevalac, AGS and SPS to RHIC and LHC energies, proton-proton to nucleus-nucleus collisions as well as other relevant systems and all measured observables. Such a database would have tremendous scientific payoff as it makes systematic studies easier and allows simpler benchmarking of theoretical models to a broad range of old and new experiments. Furthermore, there is a growing need for compilations of high-energy nuclear data for applications including stockpile stewardship, technology development for intertial confinement fusion and target and source development for upcoming facilities such as the Next Linear Collider. To enhance the utility of this database, we propose periodically performing evaluations of the data and summarizing the results in topical reviews.

  13. Open charm tomography of cold nuclear matter

    E-Print Network [OSTI]

    I. Vitev; T. Goldman; M. B. Johnson; J. W. Qiu

    2006-05-17T23:59:59.000Z

    We study the relative contribution of partonic sub-processes to D meson production and D meson-triggered inclusive di-hadrons to lowest order in perturbative QCD. While gluon fusion dominates the creation of large angle DD-bar pairs, charm on light parton scattering determines the yield of single inclusive D mesons. The distinctly different non-perturbative fragmentation of c quarks into D mesons versus the fragmentation of quarks and gluons into light hadrons results in a strong transverse momentum dependence of anticharm content of the away-side charm-triggered jet. In p+A reactions, we calculate and resum the coherent nuclear-enhanced power corrections from the final state partonic scattering in the medium. We find that single and double inclusive open charm production can be suppressed as much as the yield of neutral pions from dynamical high-twist shadowing. Effects of energy loss in p+A collisions are also investigated phenomenologically and may lead to significantly weaker transverse momentum dependence of the nuclear attenuation.

  14. Absolute nuclear material assay

    DOE Patents [OSTI]

    Prasad, Manoj K. (Pleasanton, CA); Snyderman, Neal J. (Berkeley, CA); Rowland, Mark S. (Alamo, CA)

    2012-05-15T23:59:59.000Z

    A method of absolute nuclear material assay of an unknown source comprising counting neutrons from the unknown source and providing an absolute nuclear material assay utilizing a model to optimally compare to the measured count distributions. In one embodiment, the step of providing an absolute nuclear material assay comprises utilizing a random sampling of analytically computed fission chain distributions to generate a continuous time-evolving sequence of event-counts by spreading the fission chain distribution in time.

  15. Absolute nuclear material assay

    DOE Patents [OSTI]

    Prasad, Manoj K. (Pleasanton, CA); Snyderman, Neal J. (Berkeley, CA); Rowland, Mark S. (Alamo, CA)

    2010-07-13T23:59:59.000Z

    A method of absolute nuclear material assay of an unknown source comprising counting neutrons from the unknown source and providing an absolute nuclear material assay utilizing a model to optimally compare to the measured count distributions. In one embodiment, the step of providing an absolute nuclear material assay comprises utilizing a random sampling of analytically computed fission chain distributions to generate a continuous time-evolving sequence of event-counts by spreading the fission chain distribution in time.

  16. Nuclear Fabrication Consortium

    SciTech Connect (OSTI)

    Levesque, Stephen

    2013-04-05T23:59:59.000Z

    This report summarizes the activities undertaken by EWI while under contract from the Department of Energy (DOE) � Office of Nuclear Energy (NE) for the management and operation of the Nuclear Fabrication Consortium (NFC). The NFC was established by EWI to independently develop, evaluate, and deploy fabrication approaches and data that support the re-establishment of the U.S. nuclear industry: ensuring that the supply chain will be competitive on a global stage, enabling more cost-effective and reliable nuclear power in a carbon constrained environment. The NFC provided a forum for member original equipment manufactures (OEM), fabricators, manufacturers, and materials suppliers to effectively engage with each other and rebuild the capacity of this supply chain by : � Identifying and removing impediments to the implementation of new construction and fabrication techniques and approaches for nuclear equipment, including system components and nuclear plants. � Providing and facilitating detailed scientific-based studies on new approaches and technologies that will have positive impacts on the cost of building of nuclear plants. � Analyzing and disseminating information about future nuclear fabrication technologies and how they could impact the North American and the International Nuclear Marketplace. � Facilitating dialog and initiate alignment among fabricators, owners, trade associations, and government agencies. � Supporting industry in helping to create a larger qualified nuclear supplier network. � Acting as an unbiased technology resource to evaluate, develop, and demonstrate new manufacturing technologies. � Creating welder and inspector training programs to help enable the necessary workforce for the upcoming construction work. � Serving as a focal point for technology, policy, and politically interested parties to share ideas and concepts associated with fabrication across the nuclear industry. The report the objectives and summaries of the Nuclear Fabrication Consortium projects. Full technical reports for each of the projects have been submitted as well.

  17. Assessing the nuclear age

    SciTech Connect (OSTI)

    Ackland, L.; McGuire, S.

    1986-01-01T23:59:59.000Z

    This book presents papers on nuclear weapons and arms control. Topics considered include historical aspects, the arms race, nuclear power, flaws in the non-proliferation treaty, North-South issues, East-West confrontation, Soviet decision making with regard to national defense, US and Soviet perspectives on national security, ballistic missile defense (''Star Wars''), political aspects, nuclear winter, stockpiles, US foreign policy, and military strategy.

  18. Nuclear matter equation of state including few-nucleon correlations $(A\\leq 4)$

    E-Print Network [OSTI]

    G. Röpke

    2014-11-17T23:59:59.000Z

    Light clusters (mass number $A \\leq 4$) in nuclear matter at subsaturation densities are described using a quantum statistical approach. In addition to self-energy and Pauli-blocking, effects of continuum correlations are taken into account to calculate the quasiparticle properties and abundances of light elements. Medium-modified quasiparticle properties are important ingredients to derive a nuclear matter equation of state applicable in the entire region of warm dense matter below saturation density. Moreover, the contribution of continuum states to the equation of state is considered. The effect of correlations within the nuclear medium on the quasiparticle energies is estimated. The properties of light clusters and continuum correlations in dense matter are of interest for nuclear structure calculations, heavy ion collisions, and for astrophysical applications such as the formation of neutron stars in core-collapse supernovae.

  19. Constraints on the time-scale of nuclear breakup from thermal hard-photon emission

    E-Print Network [OSTI]

    R. Ortega; D. d'Enterria; G. Martinez; D. Baiborodin; H. Delagrange; J. Diaz; F. Fernandez; H. Loehner; T. Matulewicz; R. W. Ostendorf; S. Schadmand; Y. Schutz; P. Tlusty; R. Turrisi; V. Wagner; H. W. Wilschut; N. Yahlali

    2005-08-26T23:59:59.000Z

    Measured hard photon multiplicities from second-chance nucleon-nucleon collisions are used in combination with a kinetic thermal model, to estimate the break-up times of excited nuclear systems produced in nucleus-nucleus reactions at intermediate energies. The obtained nuclear break-up time for the $^{129}${Xe} + $^{nat}${Sn} reaction at 50{\\it A} MeV is $\\Delta$$\\tau$ $\\approx$ 100 -- 300 fm/$c$ for all reaction centralities. The lifetime of the radiating sources produced in seven other different heavy-ion reactions studied by the TAPS experiment are consistent with $\\Delta$$\\tau$ $\\approx$ 100 fm/$c$, such relatively long thermal photon emission times do not support the interpretation of nuclear breakup as due to a fast spinodal process for the heavy nuclear systems studied.

  20. Nuclear dynamics induced by antiprotons

    E-Print Network [OSTI]

    Zhao-Qing Feng

    2015-05-20T23:59:59.000Z

    Reaction dynamics in collisions of antiprotons on nuclei is investigated within the Lanzhou quantum molecular dynamics model. The reaction channels of elastic scattering, annihilation, charge exchange and inelastic collisions of antiprotons on nucleons have been included in the model. Dynamics on particle production, in particular pions, kaons, antikaons and hyperons, is investigated in collisions of $\\overline{p}$ on $^{12}$C, $^{20}$Ne, $^{40}$Ca and $^{181}$Ta from a low to high incident momenta. It is found that the annihilations of $\\overline{p}$ on nucleons are of importance on the dynamics of particle production in phase space. Hyperons are mainly produced via meson induced reactions on nucleons and strangeness exchange collisions, which lead to the delayed emission in antiproton-nucleus collisions.

  1. Thermalization in collisions of large nuclei at high energies

    E-Print Network [OSTI]

    Aleksi Kurkela

    2013-03-19T23:59:59.000Z

    Hydrodynamical analysis of experimental data of ultrarelativistic heavy ion collisions seems to indicate that the hot QCD matter created in the collisions thermalizes very quickly. Theoretically, we have no idea why this should be true. In this proceeding, I will describe how the thermalization takes place in the most theoretically clean limit -- that of large nuclei at asymptotically high energy per nucleon, where the system is described by weak-coupling QCD. In this limit, plasma instabilities dominate the dynamics from immediately after the collision until well after the plasma becomes nearly in equilibrium at time t \\alpha^(-5/2)Q^(-1).

  2. Nuclear Spectra from Skyrmions

    SciTech Connect (OSTI)

    Manton, N. S. [DAMTP, University of Cambridge, Wilberforce Road, Cambridge CB3 0WA (United Kingdom)

    2009-08-26T23:59:59.000Z

    The structures of Skyrmions, especially for baryon numbers 4, 8 and 12, are reviewed. The quantized Skyrmion states are compared with nuclear spectra.

  3. Nuclear Physics from QCD

    E-Print Network [OSTI]

    U. van Kolck

    2008-12-20T23:59:59.000Z

    Effective field theories provide a bridge between QCD and nuclear physics. I discuss light nuclei from this perspective, emphasizing the role of fine-tuning.

  4. Tag: nuclear deterrence

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

    class"field-item even" property"content:encoded">

    The National Nuclear Security Administration has completed a major capital improvement project that has...

  5. Reference handbook: Nuclear criticality

    SciTech Connect (OSTI)

    Not Available

    1991-12-06T23:59:59.000Z

    The purpose for this handbook is to provide Rocky Flats personnel with the information necessary to understand the basic principles underlying a nuclear criticality.

  6. Nuclear Physics: Experiment Research

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

    UserResearcher Information print version Research Highlights Public Interest Nuclear Physics Accelerator Free Electron Laser (FEL) Medical Imaging Physics Topics Campaigns...

  7. Nuclear Safety Regulatory Framework

    Broader source: Energy.gov (indexed) [DOE]

    overall Nuclear Safety Policy & ESH Goals Safety Basis Review and Approval In the DOE governance model, contractors responsible for the facility develop the safety basis and...

  8. Nuclear power attitude trends

    SciTech Connect (OSTI)

    Nealey, S.M.

    1981-11-01T23:59:59.000Z

    The increasing vulnerability of nuclear power to political pressures fueled by public concerns, particularly about nuclear plant safety and radioactive waste disposal, has become obvious. Since Eisenhower's Atoms-for-Peace program, utility and government plans have centered on expansion of nuclear power generating capability. While supporters have outnumbered opponents of nuclear power expansion for many years, in the wake of the Three Mile Island (TMI) accident the margin of support has narrowed. The purpose of this paper is to report and put in perspective these long-term attitude trends.

  9. Management of Nuclear Materials

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

    2009-08-17T23:59:59.000Z

    To establish requirements for the lifecycle management of DOE owned and/or managed accountable nuclear materials. Cancels DOE O 5660.1B.

  10. Unclassified Controlled Nuclear Information

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

    1995-09-25T23:59:59.000Z

    To prevent unauthorized dissemination of Unclassified Controlled Nuclear Information (UCNI). Cancels DOE 5635.4 and DOE 5650.3A

  11. National Nuclear Security Administration

    Broader source: Energy.gov (indexed) [DOE]

    and Related Structures within TA-3 at Los Alamos National Laboratory, Los Alamos, New Mexico U. S. Department of Energy National Nuclear Security Administration Los Alamos Area...

  12. Nuclear | Department of 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 for4,645 3,625 1,006 492 742EnergyOnItemResearch > TheNuclear Astrophysics One of the greatNuclearNuclear Nuclear An error

  13. Jet Structure in Heavy Ion Collisions

    E-Print Network [OSTI]

    Jean-Paul Blaizot; Yacine Mehtar-Tani

    2015-03-19T23:59:59.000Z

    We review recent theoretical developments in the study of the structure of jets that are produced in ultra relativistic heavy ion collisions. The core of the review focusses on the dynamics of the parton cascade that is induced by the interactions of a fast parton crossing a quark-gluon plasma. We recall the basic mechanisms responsible for medium induced radiation, underline the rapid disappearance of coherence effects, and the ensuing probabilistic nature of the medium induced cascade. We discuss how large radiative corrections modify the classical picture of the gluon cascade, and how these can be absorbed in a renormalization of the jet quenching parameter $\\hat q $. Then, we analyze the (wave)-turbulent transport of energy along the medium induced cascade, and point out the main characteristics of the angular structure of such a cascade. Finally, color decoherence of the in-cone jet structure is discussed. Modest contact with phenomenology is presented towards the end of the review.

  14. Piezoelectric film load cell robot collision detector

    DOE Patents [OSTI]

    Lembke, John R. (Overland Park, KS)

    1989-04-18T23:59:59.000Z

    A piezoelectric load cell which can be utilized for detecting collisions and obstruction of a robot arm end effector includes a force sensing element of metallized polyvinylidene fluoride (PVDF) film. The piezoelectric film sensing element and a resilient support pad are clamped in compression between upper and lower plates. The lower plate has a central recess in its upper face for supporting the support pad and sensing element, while the upper plate has a corresponding central projection formed on its lower face for bearing on the sensing element and support pad. The upper and lower plates are dowelled together for concentric alignment and screwed together. The upper and lower plates are also adapted for mounting between the robot arm wrist and end effector.

  15. Piezoelectric film load cell robot collision detector

    DOE Patents [OSTI]

    Lembke, J.R.

    1988-03-15T23:59:59.000Z

    A piezoelectric load cell which can be utilized for detecting collisions and obstruction of a robot arm end effector includes a force sensing element of metallized polyvinylidene fluoride (PVDF) film. The piezoelectric film sensing element and a resilient support pad are clamped in compression between upper and lower plates. The lower plate has a central recess in its upper face for supporting the support pad and sensing element, while the upper plate has a corresponding central projection formed on its lower face for bearing on the sensing element and support pad. The upper and lower plates are dowelled together for concentric alignment and screwed together. The upper and lower plates are also adapted for mounting between the robot arm wrist and end effector. 3 figs.

  16. Piezoelectric film load cell robot collision detector

    DOE Patents [OSTI]

    Lembke, J.R.

    1989-04-18T23:59:59.000Z

    A piezoelectric load cell which can be utilized for detecting collisions and obstruction of a robot arm end effector includes a force sensing element of metallized polyvinylidene fluoride (PVDF) film. The piezoelectric film sensing element and a resilient support pad are clamped in compression between upper and lower plates. The lower plate has a central recess in its upper face for supporting the support pad and sensing element, while the upper plate has a corresponding central projection formed on its lower face for bearing on the sensing element and support pad. The upper and lower plates are doweled together for concentric alignment and screwed together. The upper and lower plates are also adapted for mounting between the robot arm wrist and end effector. 3 figs.

  17. Bubble collisions and measures of the multiverse

    E-Print Network [OSTI]

    Michael P. Salem

    2011-12-13T23:59:59.000Z

    To compute the spectrum of bubble collisions seen by an observer in an eternally-inflating multiverse, one must choose a measure over the diverging spacetime volume, including choosing an "initial" hypersurface below which there are no bubble nucleations. Previous calculations focused on the case where the initial hypersurface is pushed arbitrarily deep into the past. Interestingly, the observed spectrum depends on the orientation of the initial hypersurface, however one's ability observe the effect rapidly decreases with the ratio of inflationary Hubble rates inside and outside one's bubble. We investigate whether this conclusion might be avoided under more general circumstances, in particular placing the observer's bubble near the initial hypersurface. We find that it is not. As a point of reference, a substantial appendix reviews relevant aspects of the measure problem of eternal inflation.

  18. Bubble collisions and measures of the multiverse

    SciTech Connect (OSTI)

    Salem, Michael P., E-mail: salem@cosmos.phy.tufts.edu [Department of Physics, Stanford University, Stanford, CA 94305 (United States)

    2012-01-01T23:59:59.000Z

    To compute the spectrum of bubble collisions seen by an observer in an eternally-inflating multiverse, one must choose a measure over the diverging spacetime volume, including choosing an ''initial'' hypersurface below which there are no bubble nucleations. Previous calculations focused on the case where the initial hypersurface is pushed arbitrarily deep into the past. Interestingly, the observed spectrum depends on the orientation of the initial hypersurface, however one's ability observe the effect rapidly decreases with the ratio of inflationary Hubble rates inside and outside one's bubble. We investigate whether this conclusion might be avoided under more general circumstances, including placing the observer's bubble near the initial hypersurface. We find that it is not. As a point of reference, a substantial appendix reviews relevant aspects of the measure problem of eternal inflation.

  19. Bulk viscosity in heavy ion collision

    E-Print Network [OSTI]

    Victor Roy; A. K. Chaudhuri

    2012-01-20T23:59:59.000Z

    The effect of a temperature dependent bulk viscosity to entropy density ratio~($\\zeta/s$) along with a constant shear viscosity to entropy density ratio~($\\eta/s$) on the space time evolution of the fluid produced in high energy heavy ion collisions have been studied in a relativistic viscous hydrodynamics model. The boost invariant Israel-Stewart theory of causal relativistic viscous hydrodynamics is used to simulate the evolution of the fluid in 2 spatial and 1 temporal dimension. The dissipative correction to the freezeout distribution for bulk viscosity is calculated using Grad's fourteen moment method. From our simulation we show that the method is applicable only for $\\zeta/s<0.004$.

  20. Jet Structure in Heavy Ion Collisions

    E-Print Network [OSTI]

    Blaizot, Jean-Paul

    2015-01-01T23:59:59.000Z

    We review recent theoretical developments in the study of the structure of jets that are produced in ultra relativistic heavy ion collisions. The core of the review focusses on the dynamics of the parton cascade that is induced by the interactions of a fast parton crossing a quark-gluon plasma. We recall the basic mechanisms responsible for medium induced radiation, underline the rapid disappearance of coherence effects, and the ensuing probabilistic nature of the medium induced cascade. We discuss how large radiative corrections modify the classical picture of the gluon cascade, and how these can be absorbed in a renormalization of the jet quenching parameter $\\hat q $. Then, we analyze the (wave)-turbulent transport of energy along the medium induced cascade, and point out the main characteristics of the angular structure of such a cascade. Finally, color decoherence of the in-cone jet structure is discussed. Modest contact with phenomenology is presented towards the end of the review.