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arXiv 0912.2265hep-phnucl-th
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流体动力学背景下弹性能量损失的Monte-Carlo模型

A Monte-Carlo model for elastic energy loss in a hydrodynamical background

Jussi Auvinen, Kari J. Eskola, Thorsten Renk

摘要:

本文计算了在超相对论重离子碰撞中硬部分子穿过体流体动力学介质时的弹性能量损失。该模型是基于微扰量子色动力学(pQCD)截面的$2\to 2$过程中,一个硬传入的部分子被假定为与热部分子从介质中相互作用。我们在蒙特卡洛框架中模拟这种类型的相互作用,以正确地解释精确的能量-动量守恒,非程函部分子传播,部分子转换反应和从介质中创建额外的硬反冲部分子的可能性。对于介质的物理性质,我们使用流体动力学演化模型。在这一点上,我们并不打算对高横动量($P_T$)观测值进行完整的描述。相反,我们认为该模型作为一个起点,在获得一个基线的假设下,该介质是描述的热准自由部分子和它们的pQCD相互作用的高能部分子是独立的。偏离这一基线,然后要求更复杂的介质描述,以及包括高阶过程和相干效应的pQCD散射。

英文摘要:

We present a computation of elastic energy loss of hard partons traversing the bulk hydrodynamical medium created in ultrarelativistic heavy-ion collisions. The model is based on perturbative Quantum Chromodynamics (pQCD) cross sections for $2\to 2$ processes in which a hard incoming parton is assumed to interact with a thermal parton from the medium. We model the interactions of this type in a Monte-Carlo framework to account properly for exact energy-momentum conservation, non-eikonal parton propagation, parton conversion reactions and the possibility to create additional hard recoiling partons from the medium. For the thermodynamical properties of the medium we use a hydrodynamical evolution model. We do not aim at a full description of high transverse momentum ($P_T$) observables at this point. Rather, we view the model as a starting point in obtaining a baseline of what to expect under the assumptions that the medium is describable by thermal quasifree partons and that their pQCD interactions with the high-energy partons are independent. Deviations from this baseline then call for more sophisticated medium description, as well as inclusion of higher-order processes and coherence effects in the pQCD scatterings.

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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