Eur. Phys. J. C (2008) 55: 463-467
https://doi.org/10.1140/epjc/s10052-008-0609-3

Regular Article - Theoretical Physics

Partonic effect on anisotropic flows of Ω baryon for Au+Au at 62.4 and 200 GeV/c

¹ Nuclear Physics Division, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, P.O. Box 800-204, Shanghai, 201800, P.R. China
² Institute of Particle Physics, Huazhong Normal University, Wuhan, 430079, P.R. China
³ Physics Department, Brookhaven National Lab., Upton, New York, 11973, USA
⁴ University of California, Los Angeles, California, 90095, USA

^* e-mail: zuojiaxu@sinap.ac.cn

Received: 11 December 2007
Revised: 25 February 2008
Published online: 15 May 2008

Abstract

The elliptic flow v₂ and the fourth order anisotropic flow v₄ of (Ω+Ω̄) have been studied in the framework a parton–hadronic transport model, namely a multi-phase transport (AMPT) model, for ¹⁹⁷Au+¹⁹⁷Au collisions at = 200 GeV and 62.4 GeV. The transverse momentum (p_T) and the transverse kinetic energy (m_T-m₀) dependence of v₂ and v₄ are presented. The calculation in the AMPT model seems consistent with the STAR data. The results show that the v₂ of (Ω+Ω̄) in 200 GeV obeys the constituent quark number scaling that has been observed for other mesons and baryons. Comparison of (Ω+Ω̄) elliptic flow v₂ in the default version of AMPT, the melting version of AMPT and the RQMD model calculation, shows that the parton cascade process is important to reproduce the sizeable v₂, and the string melting AMPT model preferably reproduces (Ω+Ω̄) elliptic flow v₂ in ¹⁹⁷Au+¹⁹⁷Au collisions at = 200 GeV. The v₂ of (Ω+Ω̄) in the 62.4 and 200 GeV collisions seem similar, and the p_T dependence of (Ω+Ω̄) baryons’ v₄ in 62.4 GeV and 200 GeV looks also similar in the string melting AMPT model, which indicates that a similar partonic matter phase has been reached in both energies.