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arXiv 1012.0728nucl-th
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热QCD介质中辐射能量损失模型的比较

Comparison of radiative energy loss models in a hot QCD medium

Marta Verweij

摘要:

在重离子碰撞中,高$p_{T}$强子产生的抑制被认为是由于胶子辐射离开QCD介质中的硬部分子的能量损失。现有的QCD辐射能量损失模型在色荷介质中给出的部分子与介质耦合强度的估计相差$5$倍。我们将对计算轻夸克和胶子能量损失的两种不同的形式主义进行并排比较:多重软散射近似(ASW-MS)和不透明度膨胀形式主义(ASW-SH和WHDG-rad)。一个共同的时间-温度曲线用于表征介质。结果与RHIC能区的单强子抑制$R_{AA}$进行了比较。此外,还讨论了散射中心均匀分布和非均匀分布的影响。我们发现,使用一个等效的砖高估了长的部分子轨迹的能量损失。

英文摘要:

The suppression of high $p_{T}$ hadron production in heavy ion collisions is thought to be due to energy loss by gluon radiation off hard partons in a QCD medium. Existing models of QCD radiative energy loss in a color-charged medium give estimates of the coupling strength of the parton to the medium which differ by a factor of $5$. We will present a side-by-side comparison of two different formalisms to calculate the energy loss of light quarks and gluons: the multiple soft scattering approximation (ASW-MS) and the opacity expansion formalism (ASW-SH and WHDG-rad). A common time-temperature profile is used to characterize the medium. The results are compared to the single hadron suppression $R_{AA}$ at RHIC energies. In addition the influcence of homogeneous and non-homogeneous distribution of scattering centers is discussed. We find that using an equivalent brick overestimates the energy loss for long parton trajectories.

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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