Energy dependence of elliptic flow from heavy-ion collision models

Journal Article · Mon Nov 15 00:00:00 EST 2010 · Physical Review. C, Nuclear Physics

DOI:https://doi.org/10.1103/PHYSREVC.82.054908· OSTI ID:21499206

Nasim, Md; Mohanty, Bedangadas ^[1]; Kumar, Lokesh ^[2]; Netrakanti, Pawan Kumar ^[3]

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1. Variable Energy Cyclotron Centre, Kolkata 700064 (India)
2. Kent State University, Kent, Ohio 44242 (United States)
3. Bhabha Atomic Research Centre, Mumbai 400 085 (India)

We have compared the experimental data on charged-particle elliptic flow parameter (v{sub 2}) in Au + Au collisions at midrapidity for {radical}(s{sub NN})=9.2, 19.6, 62.4, and 200 GeV with results from various models in heavy-ion collisions such as the ultrarelativistic quantum molecular dynamics (UrQMD) model, a multiphase transport model (AMPT), and heavy-ion jet interaction generator (HIJING). We observe that the average v{sub 2} (<v{sub 2}>) from the transport model UrQMD agrees well with the measurements at {radical}(s{sub NN})=9.2 GeV but increasingly falls short of the experimental <v{sub 2}> values as the beam energy increases. The difference in <v{sub 2}> is of the order of 60% at {radical}(s{sub NN})=200 GeV. The <v{sub 2}> results from HIJING are consistent with zero, while those from AMPT with default settings, a model based on HIJING with additional initial- and final-state rescattering effects included, give a <v{sub 2}> value of about 4% for all the beam energies studied. This is in contrast to an increase in <v{sub 2}> with beam energy for the experimental data. A different version of the AMPT model, which includes partonic effects and quark coalescence as a mechanism of hadronization, gives higher values of <v{sub 2}> among the models studied and is in agreement with the measured <v{sub 2}> values at {radical}(s{sub NN})=200 GeV. These studies show that the experimental <v{sub 2}> has substantial contribution from partonic interactions at {radical}(s{sub NN})=200 GeV, whose magnitude reduces with decrease in beam energy. We also compare the available data on the transverse momentum and pseudorapidity dependence of v{sub 2} to those from these models.

• OSTI ID: 21499206
• Journal Information: Physical Review. C, Nuclear Physics, Vol. 82, Issue 5; Other Information: DOI: 10.1103/PhysRevC.82.054908; (c) 2010 The American Physical Society; ISSN 0556-2813
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ATOM-ATOM COLLISIONS
BEAMS
COALESCENCE
COLLISIONS
COMPARATIVE EVALUATIONS
ENERGY DEPENDENCE
GEV RANGE
GOLD
HEAVY ION REACTIONS
HEAVY IONS
INTERACTIONS
MOLECULAR DYNAMICS METHOD
PARTICLE RAPIDITY
QUARKS
RELATIVISTIC RANGE
RESCATTERING
TRANSPORT THEORY
TRANSVERSE MOMENTUM
ATOM COLLISIONS
CALCULATION METHODS
CHARGED PARTICLES
ELEMENTS
ENERGY RANGE
EVALUATION
FERMIONS
IONS
LINEAR MOMENTUM
METALS
NUCLEAR REACTIONS
PARTICLE PROPERTIES
SCATTERING
TRANSITION ELEMENTS