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arXiv 0910.3528hep-ph
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P_T向运动学极限增长的核抑制因子

The Nuclear Suppression Factor for P_T increasing towards the Kinematic Limit

Thorsten Renk

摘要:

与用核修正因子R_AA表示的质子-质子(p-p)碰撞的比例期望值相比,在超相对论重离子(A-A)碰撞中高横动量P_T强子的产生受到抑制,这一现象在实验上得到了证实,并可追溯到硬部分子簇射与软体物质之间的相互作用。物理直觉表明,当部分子产生的硬尺度远大于介质中典型的动量尺度(如温度T)时,介质修正就不再重要,因此当P_T >> T时,R_AA(P_T)-> 1。然而,R_AA不是一个“简单”的可观测量,而是由许多不同的机制影响P_T增加时发生的事情。特别地,即使在反应的运动学极限下探测强子动量,R_AA也不一定接近1。本工作的目的是识别和讨论这种机制,并提出不同的模型期望,如果我们可以测量到硬强子产生的运动学极限的抑制,并给出RHIC和LHC的P_T依赖性的预测。

英文摘要:

The suppression of high transverse momentum P_T hadron production in ultrarelativistic heavy-ion (A-A) collisions as compared to the scaled expectation from proton-proton (p-p) collisions expressed as the nuclear modification factor R_AA is experimentally well established and can be traced back to interactions between the hard parton shower and the soft bulk matter. Physical intuition suggests that the medium modification should cease to be important when the hard scale of parton production is much larger than the typical momentum scale in the medium (e.g. the temperature T) and that consequently R_AA(P_T) -> 1 for P_T >> T. However, R_AA is not a 'simple' observable, but rather results from many different mechanisms which influence what happens when P_T increases. In particular, R_AA does not necessarily approch unity even if the hadron momentum is probed at the kinematic limit of the reaction. The aim of this work is to identify and discuss such mechanisms and to present different model expectations of what one would find if one could measure suppression out to the kinematic limit for hard hadron production and give predictions for the P_T dependence at both RHIC and LHC.

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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