# Centrality dependence of charged hadron and strange hadron elliptic flow from $\sqrt{s_{NN}}$ = 200 GeV Au+Au collisions

Abstract : We present STAR results on the elliptic flow v_2 of charged hadrons, strange and multi-strange particles from sqrt(s_NN) = 200 GeV Au+Au collisions at RHIC. The detailed study of the centrality dependence of v_2 over a broad transverse momentum range is presented. Comparison of different analysis methods are made in order to estimate systematic uncertainties. In order to discuss the non-flow effect, we have performed the first analysis of v_2 with the Lee-Yang Zero method for K_s^0 and Lambda. In the relatively low p_T region, p_T <= 2 GeV/c, a scaling with m_T - m is observed for identified hadrons in each centrality bin studied. We do not observe v_2(p_T) scaled by the participant eccentricity to be independent of centrality. At higher p_T, 2 GeV/c <= p_T <= 6 GeV/c, v_2 scales with quark number for all hadrons studied. For the multi-strange hadron Omega, which does not suffer appreciable hadronic interactions, the values of v_2 are consistent with both m_T - m scaling at low p_T and number-of-quark scaling at intermediate p_T. As a function of collision centrality, an increase of p_T-integrated v_2 scaled by the participant eccentricity has been observed, indicating a stronger collective flow in more central Au+Au collisions.
Document type :
Journal articles

http://hal.in2p3.fr/in2p3-00221135
Contributor : Dominique Girod <>
Submitted on : Monday, January 28, 2008 - 2:00:40 PM
Last modification on : Thursday, August 6, 2020 - 6:23:56 PM

### Citation

B.I. Abelev, M.M. Aggarwal, Z. Ahammed, B.D. Anderson, D. Arkhipkin, et al.. Centrality dependence of charged hadron and strange hadron elliptic flow from $\sqrt{s_{NN}}$ = 200 GeV Au+Au collisions. Physical Review C, American Physical Society, 2008, 77, pp.054901. ⟨10.1103/PhysRevC.77.054901⟩. ⟨in2p3-00221135⟩

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