부산대학교 도서관

The transverse momentum dependence of the anisotropic flow v2for ?, K, nucleon, ?, ? and ? is studied for Au+Au collisions at within two independent string-hadron transport approaches (RQMD and UrQMD). Although both models reach only 60% of the absolute magnitude of the measured v2, they both predict the particle-type dependence of v2, as observed by the RHIC experiments: v2exhibits a hadron-mass hierarchy (HMH) in the low pTregion and a number-of-constituent-quark (NCQ) dependence in the intermediate pTregion. The failure of the hadronic models to reproduce the absolute magnitude of the observed v2indicates that transport calculations of heavy-ion collisions at RHIC must incorporate interactions among quarks and gluons in the early, hot and dense phase. The presence of an NCQ scaling in the string-hadron model results suggests that the particle-type dependences observed in heavy-ion collisions at intermediate pTmight be related to the hadronic cross sections in vacuum rather than to the hadronization process itself.