标题： 计算淬火权重 显示英文标题

标题： Calculating Quenching Weights

摘要： 我们计算了硬子辐射额外能量分数的概率（“淬火权重”），这是由于在空间扩展的QCD物质中散射引起的。 这项研究基于对有限介质内路径长度的精确处理，包括动态膨胀介质的情况，并扩展到介质诱导的胶子辐射模式的角度依赖性。 所有计算都在多重软散射近似（Baier-Dokshitzer-Mueller-Peigné-Schiff--Zakharov “BDMPS-Z”-形式）和单次硬散射近似（N=1透明度近似）中进行。 通过比较，我们建立了一个运输系数、德拜屏蔽质量与透明度之间的简单关系，这两种近似都得到相似的结果。 除了本文外，还提供了一个计算淬火权重的CPU成本低廉的数值子程序。 为了说明其应用，我们讨论了核-核碰撞中强子横向动量谱的抑制。 值得注意的是，由于有限介质内路径长度带来的运动学约束，显著降低了核修改因子的横向动量依赖性，从而与相对论重离子碰撞机（RHIC）测量的数据一致。 显示英文摘要

摘要： We calculate the probability (``quenching weight'') that a hard parton radiates an additional energy fraction due to scattering in spatially extended QCD matter. This study is based on an exact treatment of finite in-medium path length, it includes the case of a dynamically expanding medium, and it extends to the angular dependence of the medium-induced gluon radiation pattern. All calculations are done in the multiple soft scattering approximation (Baier-Dokshitzer-Mueller-Peign\'e-Schiff--Zakharov ``BDMPS-Z''-formalism) and in the single hard scattering approximation (N=1 opacity approximation). By comparison, we establish a simple relation between transport coefficient, Debye screening mass and opacity, for which both approximations lead to comparable results. Together with this paper, a CPU-inexpensive numerical subroutine for calculating quenching weights is provided electronically. To illustrate its applications, we discuss the suppression of hadronic transverse momentum spectra in nucleus-nucleus collisions. Remarkably, the kinematic constraint resulting from finite in-medium path length reduces significantly the transverse momentum dependence of the nuclear modification factor, thus leading to consistency with the data measured at the Relativistic Heavy Ion Collider (RHIC).