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

Abstract

The elliptic flow v2 and the fourth order anisotropic flow v4 of (Ω+Ω) have been studied in the framework a parton–hadronic transport model, namely a multi-phase transport (AMPT) model, for 197Au+197Au collisions at $\sqrt{s_{NN}}$ = 200 GeV and 62.4 GeV. The transverse momentum (pT) and the transverse kinetic energy (mT-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+Ω) in 200 GeV obeys the constituent quark number scaling that has been observed for other mesons and baryons. Comparison of (Ω+Ω) 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+Ω) elliptic flow v2 in 197Au+197Au collisions at $\sqrt{s_{NN}}$ = 200 GeV. The v2 of (Ω+Ω) in the 62.4 and 200 GeV collisions seem similar, and the pT dependence of (Ω+Ω) 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.