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arXiv 0801.3466nucl-ex
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sqrt(s_NN)= 200 GeV Au+Au碰撞中带电强子和奇异强子椭圆流的中心性依赖

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

STAR Collaboration, B. I. Abelev

摘要:

本文给出了在RHIC上由sqrt(s_NN)= 200 GeV Au+Au碰撞产生的带电强子、奇异粒子和多奇异粒子椭圆流v_2的STAR结果。本文详细研究了在宽横动量范围内v_2的中心性依赖关系。比较了不同的分析方法,以估计系统的不确定性。为了讨论非流动效应,我们用李-杨零点法对K_s^0和λ进行了v_2的首次分析。在p_T <= 2GeV/c的相对低的p_T区,在所研究的每个中心性仓中,观测到了与m_T-m有关的标度。然而,我们没有观察到v_2(p_T)标度的参与者偏心是独立的中心性。在较高的p_T,2GeV/c <= p_T <= 6 GeV/c时,研究了所有强子的v_2夸克数标度。对于多奇异强子Omega,它不受明显的强子相互作用,v_2值在低p_T时与mT-m标度一致,在中等p_T时与夸克数标度一致。作为碰撞中心性的函数,pT积分v_2随参与者偏心率的增加而增加,表明在更中心的Au+Au碰撞中有更强的集体流。

英文摘要:

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.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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