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arXiv 1003.1692hep-phnucl-exnucl-th
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RHIC上Au+Au碰撞中重夸克偶素的末态多重散射抑制

On heavy-quarkonia suppression by final-state multiple scatterings in most central Au+Au collisions at RHIC

Bin Wu, Bo-Qiang Ma

摘要:

研究了RHIC能区Au~+~Au碰撞中重夸克偶素在末态多重散射下的抑制。我们首先在大$N_c$下计算了Bjorken扩展QGP中重夸克偶素在多重散射下的存活几率。然后,在一个简化的模型中,考虑了大多数中心Au~+~Au碰撞中的末态多重散射,计算了重夸克偶素产生的核修正因子$R_{AA}$的快度依赖性.在我们的公式中还引入了一个常数$P_0$来估计可能的冷核效应。通过对RHIC上大多数中心Au + Au碰撞中$\sqrt{s_{NN}}=200$产生的数据进行拟合,发现在微扰热QCD中,输运系数$\hat{q}_0\simeq(0.33-0.95)~\mbox{GeV}^2$ /fm为$ε_0\simeq(1.39-5.62)~\mbox{GeV}/\mbox{fm}^3$,相应地,$τ_0$处的能量密度也为fm.更好地理解冷核效应对于我们获得更准确的分析至关重要。我们估计的输运系数$\hat{q}_0$的小值与文献[31]中通过分析高$p_T$强子谱得到的结果形成鲜明对比。

英文摘要:

We study heavy-quarkonia suppression under final-state multiple scatterings in most central Au~+~Au collisions at RHIC energy. We first calculate the survival probability of a heavy quarkonium under multiple scattering in Bjorken's expanding QGP at large $N_c$. Then, we calculate the rapidity dependence of the nuclear modification factor $R_{AA}$ for heavy-quarkonia production by considering final-state multiple scatterings in most central Au~+~Au collisions in a simplified model. In our formula a constant $P_0$ is also introduced to estimate the possible cold nuclear effects. By fitting the data for $J/Ψ$ production in most central Au + Au collisions at $\sqrt{s_{NN}}=200$~GeV at RHIC, we find that the transportation coefficient $\hat{q}_0\simeq(0.33-0.95)~\mbox{GeV}^2$/fm, and, accordingly, the energy density at $τ_0$ is $ε_0\simeq(1.39-5.62)~\mbox{GeV}/\mbox{fm}^3$ in perturbative thermal QCD. A better understanding of cold nuclear effects is essential for us to get a more accurate analysis. The small values of the transportation coefficient $\hat{q}_0$ in our estimate are in sharp contrast with those obtained by the analysis of high-$p_T$ hadron spectra in Ref. [31].

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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