arXiv 1502.037572015-02nucl-thhep-ph

重夸克的$R_{AA}$和$v_2$之谜的一个解

Toward a solution to the $R_{AA}$ and $v_2$ puzzle for heavy quarks

Santosh K. Das, Francesco Scardina, Salvatore Plumari, Vincenzo Greco

备注：: 7 pages, 6 figures, Accepted for publication in Physics Letters B
发表信息：: Phys. Lett. B 747 (2015) 260
DOI：: 10.1016/j.physletb.2015.06.003

摘要：

重夸克是研究夸克-胶子等离子体性质的一个独特的探针。在RHIC和LHC能区都观察到核修正因子$R_{AA}(p_T)$和椭圆流$v_2(p_T)$之间的一个令人困惑的关系，这对现有的模型，特别是对D介子的模型提出了挑战。我们讨论了如何重夸克阻力系数的温度依赖性是负责这样一个难题的很大一部分。特别是，我们考虑了四种不同的模型来评估通过夸克-胶子等离子体（QGP）传播的阻力和扩散系数的温度依赖性。所有四个不同的模型都被设置为重现在RHIC和LHC能量下实验中观察到的相同的$R_{AA}(p_T)$。我们指出，对于相同的$R_{AA}(p_T)$，可以产生2-3倍的$v_2$，这取决于重夸克阻力系数的温度依赖性。非递减阻力系数$ T \rightarrow\ T_c \,$是同时描述$R_{AA}(p_T)$和$v_2(p_T)$的主要成分。

英文摘要：

The heavy quarks constitutes a unique probe of the quark-gluon plasma properties. Both at RHIC and LHC energies a puzzling relation between the nuclear modification factor $R_{AA}(p_T)$ and the elliptic flow $v_2(p_T)$ has been observed which challenged all the existing models, especially for D mesons. We discuss how the temperature dependence of the heavy quark drag coefficient is responsible for a large part of such a puzzle. In particular, we have considered four different models to evaluate the temperature dependence of drag and diffusion coefficients propagating through a quark gluon plasma (QGP). All the four different models are set to reproduce the same $R_{AA}(p_T)$ observed in experiments at RHIC and LHC energy. We point out that for the same $R_{AA}(p_T)$ one can generate 2-3 times more $v_2$ depending on the temperature dependence of the heavy quark drag coefficient. A non-decreasing drag coefficient as $ T \rightarrow\ T_c \,$ is a major ingredient for a simultaneous description of $R_{AA}(p_T)$ and $v_2(p_T)$.

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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英文摘要：

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