System size, energy and centrality dependence of strange hadron elliptic flow at STAR

• Published in: Journal of physics. G, Nuclear and particle physics Nuclear and particle physics, 2009-06, Vol.36 (6), p.064047-064047 (6), Article 064047
• Main Author: Masui, H
• Format: Article
• Language: English
• Subjects: Exact sciences and technology; Nuclear physics; Physics; The physics of elementary particles and fields
• ISSN: 0954-3899; 1361-6471
• DOI: 10.1088/0954-3899/36/6/064047

The elliptic flow (v2) pattern in terms of hadron mass and transverse momentum pT is qualitatively described for pT < 2 GeV/c by ideal hydrodynamics in Au + Au collisions at the Relativistic Heavy Ion Collider (RHIC). In addition, for pT = 2-6 GeV/c the measured v2 follow a universal scaling by the number of quarks explained by quark coalescence/recombination models. These observations suggest that a partonic collectivity develops in the matter in early stage of heavy ion collisions. Centrality as well as system size and energy dependence of v2 is important to shed light on the underlying collision dynamics in heavy ion collisions. We present the measurements of centrality dependence of v2 at and 62.4 GeV in Au + Au and Cu + Cu collisions for K0S,, Lambda, Xi and Omega at STAR experiment. We focus on the recent Cu + Cu results and discuss the centrality dependence of v2 as well as the number of quark scaling as a function of transverse kinetic energy at different system size and energies. We also discuss the eccentricity scaled v2 for identified hadrons and implications that ideal hydrodynamical limit has not been reached at the RHIC.