Centrality dependence of charged hadron and strange hadron elliptic flow from sqrt(s_NN) = 200 GeV Au+Au collisions

The STAR collaboration Abelev, B.I. ; Aggarwal, M.M. ; Ahammed, Z. ; et al.
Phys.Rev.C 77 (2008) 054901, 2008.
Inspire Record 777954 DOI 10.17182/hepdata.96906

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. However, 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.

28 data tables

$v_{2}(\eta)$ for charged hadrons, $0.15 < p_{T} < 2.0$ GeV/c, centrality $10-40\%$, from $Au+Au$ collisions at $\sqrt{s_{NN}} = 200$ GeV.

$v_{2}$ as a function of $p_{T}$ for charged hadrons with $|\eta| < 1.0$ in 10–40$%$ $Au+Au$ collisions, at $\sqrt{s_{NN}} = 200$ GeV, from the Event Plane method (open circles).

$v_{2}$ as a function of $p_{T}$ for charged hadrons with $|\eta| < 1.0$ in 10–40$%$ $Au+Au$ collisions, at $\sqrt{s_{NN}} = 200$ GeV, from the 4-particle cumulant method (solid squares).

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