PaperPanorama
FAQ

Nuclear Theory·nucl-th

Thursday·May 26, 2016

9 papers—4 primary·5 cross-listed

All9Primary4Cross-lists5
  1. 01

    Freezeout conditions in proton-proton collisions at the top RHIC and LHC energies

    Sabita Das🇨🇳 · Debadeepti Mishra🇮🇳 · Sandeep Chatterjee🇮🇳 · Bedangadas Mohanty🇮🇳

    The freezeout conditions in proton-proton collisions at , and GeV have been extracted by fits to the mean hadron yields at mid-rapidity within the framework of the statistical model of an ideal gas of hadrons and resonances in the grand canonical ensemble. The variation of the extracted freezeout thermal parameters and the goodness of the fits with are discussed. We find the extracted temperature and baryon chemical potential of the freezeout surface to be similar in p+p and heavy ion collisions. On the other hand, the thermal behaviour of the strange hadrons is qualitatively different in p+p as compared to A+A. We find an additional parameter accounting for non-equilibrium strangeness production is essential for describing the p+p data. This is in contrast to A+A where the non-equilibrium framework could be successfully replaced by a sequential and complete equilibrium model with an early freezeout of the strange hadrons.

    nucl-thnucl-exPRC(2017)·26 citations
  2. 02

    Global analysis of isospin dependent microscopic nucleon-nucleus optical potential in Dirac Bruckner Hartree-Fock approach

    Ruirui Xu · Zhongyu Ma · Yue Zhang · Yuan Tian (China Institute of Atomic Energy, Beijing 102413) · E. N. E. van Dalen · H. Müther (Institut für Theoretische Physik, Universität Tübingen, Germany)

    The Microscopic Otical Model Potential is evaluated within a relativistic scheme which provides a natural and consistent relation between the spin-orbit part and the central part of the potential. The Dirac-Brueckner-Hartree-Fock (DBHF) approach provides such a microscopic relativistic scheme, which is based on a realistic nucleon-nucleon interaction and reproduce the saturation properties of symmetric nuclear matter without any adjustable parameter. Its solution using the projection technique within the subtracted T-matrix (STM) representation provides a reliable extension to asymmetric nuclear matter, which is important to describe the features of the isospin asymmetric nuclei. Therefore, the present work aims to perform a global analysis of the isospin-dependent nucleon-nucleus MOP based on the DBHF calculation in symmetric and asymmetric nuclear matter. The DBHF is used to evaluate the relativistic structure of the nucleon self-energies in nuclear matter at various densities and asymmetries. The Schrödinger equivalent potentials of finite nuclei are derived from these Dirac components by a local density approximation (LDA). The nucleon-nucleus scattering calculations are carried out for a broad spectrum and scattering experiments below 200 MeV with targets ranging from C to Pb.

    nucl-thPRC(2016)·22 citations
  3. 03

    Single electrons from heavy-flavor mesons in relativistic heavy-ion collisions

    Taesoo Song🇩🇪 · Hamza Berrehrah🇩🇪 · Juan M. Torres-Rincon🇩🇪 · Laura Tolos🇩🇪 · Daniel Cabrera🇪🇸 · Wolfgang Cassing🇩🇪 · Elena Bratkovskaya🇩🇪

    We study the single electron spectra from and meson semileptonic decays in Au+Au collisions at 200, 62.4, and 19.2 GeV by employing the parton-hadron-string dynamics (PHSD) transport approach that has been shown to reasonably describe the charm dynamics at RHIC and LHC energies on a microscopic level. In this approach the initial heavy quarks are produced by using the PYTHIA which is tuned to reproduce the FONLL calculations. The produced heavy quarks interact with off-shell massive partons in QGP with scattering cross sections which are calculated in the dynamical quasi-particle model (DQPM). At energy densities close to the critical energy density the heavy quarks are hadronized into heavy mesons through either coalescence or fragmentation. After hadronization the heavy mesons interact with the light hadrons by employing the scattering cross sections from an effective Lagrangian. The final heavy mesons then produce single electrons through semileptonic decay. We find that the PHSD approach well describes the nuclear modification factor and elliptic flow of single electrons in d+Au and Au+Au collisions at 200 GeV and the elliptic flow in Au+Au reactions at 62.4 GeV from the PHENIX collaboration, however, the large at 62.4 GeV is not described at all. Furthermore, we make predictions for the of mesons and of single electrons at the lower energy of 19.2 GeV. Additionally, the medium modification of the azimuthal angle between a heavy quark and a heavy antiquark is studied. We find that the transverse flow enhances the azimuthal angular distributions close to 0 because the heavy flavors strongly interact with nuclear medium in relativistic heavy-ion collisions and almost flow with the bulk matter.

    nucl-thnucl-exPRC(2017)·38 citations
  4. 04

    Emergent Kink Statistics at Finite Temperature

    Miguel Angel Lopez-Ruiz🇺🇸 · Tochtli Yepez-Martinez🇺🇸 · Adam P. Szczepaniak🇺🇸 · Jinfeng Liao🇺🇸

    In this paper we use 1D quantum mechanical systems with Higgs-like interaction potential to study the emergence of topological objects at finite temperature. Two different model systems are studied, the standard double-well potential model and a newly introduced discrete kink model. Using Monte-Carlo simulations as well as analytic methods, we demonstrate how kinks become abundant at low temperatures. These results may shed useful insights on how topological phenomena may occur in QCD.

    nucl-thhep-phNPA(2017)·2 citations

Affiliations

first authorsco-authorsvia INSPIRE