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Title: Charged-particle rapidity density in Au+Au collisions in a quark combination model

Abstract

Rapidity/pseudorapidity densities for charged particles and their centrality, rapidity, and energy dependence in Au+Au collisions at the Relativistic Heavy Ion Collider are studied in a quark combination model. Using a Gaussian-type rapidity distribution for constituent quarks as a result of Landau hydrodynamic evolution, the data at {radical}(s{sub NN})=130,200 GeV at various centralities in full pseudorapidity range are well described, and the charged-particle multiplicities are reproduced as functions of the number of participants. The energy dependence of the shape of the dN{sub ch}/d{eta} distribution is also described at various collision energies {radical}(s{sub NN})=200,130,62.4 GeV in central collisions with same value of parameters except 19.6 GeV. The calculated rapidity distributions and yields for the charged pions and kaons in central Au+Au collisions at {radical}(s{sub NN})=200 GeV are compared with experimental data of the BRAHMS Collaboration.

Authors:
 [1]; ;  [2]
  1. Department of Physics, Qufu Normal University, Shandong 273165 (China)
  2. Department of Physics, Shandong University, Shandong 250100 (China)
Publication Date:
OSTI Identifier:
20995153
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. C, Nuclear Physics; Journal Volume: 75; Journal Issue: 3; Other Information: DOI: 10.1103/PhysRevC.75.034904; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS; BROOKHAVEN RHIC; CHARGED PARTICLES; COLLISIONS; DENSITY; DISTRIBUTION; ENERGY DEPENDENCE; GEV RANGE 10-100; GEV RANGE 100-1000; HEAVY ION REACTIONS; KAONS; MASS NUMBER; PARTICLE RAPIDITY; PIONS; QUARK MODEL; QUARKS

Citation Formats

Shao Fenglan, Yao Tao, and Xie Qubing. Charged-particle rapidity density in Au+Au collisions in a quark combination model. United States: N. p., 2007. Web. doi:10.1103/PHYSREVC.75.034904.
Shao Fenglan, Yao Tao, & Xie Qubing. Charged-particle rapidity density in Au+Au collisions in a quark combination model. United States. doi:10.1103/PHYSREVC.75.034904.
Shao Fenglan, Yao Tao, and Xie Qubing. Thu . "Charged-particle rapidity density in Au+Au collisions in a quark combination model". United States. doi:10.1103/PHYSREVC.75.034904.
@article{osti_20995153,
title = {Charged-particle rapidity density in Au+Au collisions in a quark combination model},
author = {Shao Fenglan and Yao Tao and Xie Qubing},
abstractNote = {Rapidity/pseudorapidity densities for charged particles and their centrality, rapidity, and energy dependence in Au+Au collisions at the Relativistic Heavy Ion Collider are studied in a quark combination model. Using a Gaussian-type rapidity distribution for constituent quarks as a result of Landau hydrodynamic evolution, the data at {radical}(s{sub NN})=130,200 GeV at various centralities in full pseudorapidity range are well described, and the charged-particle multiplicities are reproduced as functions of the number of participants. The energy dependence of the shape of the dN{sub ch}/d{eta} distribution is also described at various collision energies {radical}(s{sub NN})=200,130,62.4 GeV in central collisions with same value of parameters except 19.6 GeV. The calculated rapidity distributions and yields for the charged pions and kaons in central Au+Au collisions at {radical}(s{sub NN})=200 GeV are compared with experimental data of the BRAHMS Collaboration.},
doi = {10.1103/PHYSREVC.75.034904},
journal = {Physical Review. C, Nuclear Physics},
number = 3,
volume = 75,
place = {United States},
year = {Thu Mar 15 00:00:00 EDT 2007},
month = {Thu Mar 15 00:00:00 EDT 2007}
}
  • We present results for final state charged-particle (pseudo-)rapidity distributions in p+p/p+p and Pb+Pb/Au+Au at ultra high energies (17.3 GeV{<=}{radical}(s{sub NN}){<=}14 TeV) from the Ultra-relativistic Quantum Molecular Dynamics (UrQMD-v2.3) model. In addition, excitation functions of produced charged-particle multiplicities (N{sub ch}) and pseudorapidity spectra are investigated up to CERN Large Hadron Collider energies. Good agreement is observed between UrQMD and measured pseudorapidity distributions of charged particles up to the highest Tevatron and SppS energies.
  • The pseudorapidity behavior of the azimuthal anisotropy parameters v{sub 1} and v{sub 2} of inclusive charged (h{sup {+-}}) hadrons and their dependence on centrality has been studied in Au+Au collisions at full relativistic-heavy-ion-collider energy of {radical}(s{sub NN})=200 GeV within the microscopic quark-gluon string model (QGSM). The QGSM simulation results for the directed flow v{sub 1} show antiflow alignment within the pseudorapidity range |{eta}|{<=}2 in fair agreement with the experimental v{sub 1}({eta}) data, but it cannot reproduce the further development of the antiflow up to |{eta}|{approx_equal}3.5. The {eta} dependence of the elliptic flow v{sub 2} extracted from the simulations agrees wellmore » with the experimental data in the whole pseudorapidity range for different centrality classes. The centrality dependence of the integrated elliptic flow of charged hadrons in the QGSM almost coincides with the PHOBOS experimental distribution. The transverse momentum dependence of the elliptic flow of identified ({pi}{sup {+-}},K{sup {+-}},p,p) and inclusive charged hadrons is studied also. The model reproduces quantitatively the low-p{sub T} part of the distributions rather well, but it underestimates the measured elliptic flow for transverse momenta p{sub T}>1 GeV/c. Qualitatively, however, the model can reproduce the saturation of the v{sub 2}(p{sub T}) spectra with rising p{sub T} as well as the crossing of the elliptic flow for mesons and baryons.« less
  • Longitudinal density correlations of produced matter in Au+Au collisions at sqrt(s{sub NN})=200 GeV have been measured from the inclusive charged particle distributions as a function of pseudorapidity window sizes. The extracted {alpha}{xi} parameter, related to the susceptibility of the density fluctuations in the long-wavelength limit, exhibits a nonmonotonic behavior as a function of the number of participant nucleons, N{sub part}. A local maximum is seen at N{sub part}{approx}90, with corresponding energy density based on the Bjorken picture of {epsilon}{sub Bj}{tau}{approx}2.4 GeV/(fm{sup 2}c) with a transverse area size of 60 fm2. This behavior may suggest a critical phase boundary based onmore » the Ginzburg-Landau framework.« less
  • Longitudinal density correlations of produced matter in Au+Au collisions at {radical}(s{sub NN})=200 GeV have been measured from the inclusive charged particle distributions as a function of pseudorapidity window sizes. The extracted {alpha}{xi} parameter, related to the susceptibility of the density fluctuations in the long-wavelength limit, exhibits a nonmonotonic behavior as a function of the number of participant nucleons, N{sub part}. A local maximum is seen at N{sub part}{approx}90, with corresponding energy density based on the Bjorken picture of {epsilon}{sub Bj}{tau}{approx}2.4 GeV/(fm{sup 2}c) with a transverse area size of 60 fm{sup 2}. This behavior may suggest a critical phase boundary basedmore » on the Ginzburg-Landau framework.« less
  • The charged-particle pseudorapidity density dN{sub ch}/d{eta} has been measured for Au+Au collisions at s{sub NN}=130 GeV at RHIC, using the PHOBOS apparatus. The total number of charged particles produced for the 3% most-central Au+Au collisions for |{eta}|{<=}5.4 is found to be 4200{+-}470 . The evolution of dN{sub ch}/d{eta} with centrality is discussed, and compared to model calculations and to data from proton-induced collisions. The data show an enhancement in charged-particle production at midrapidity, while in the fragmentation regions, the results are consistent with expectations from pp and pA scattering.