Hard collinear gluon radiation and multiple scattering in a medium
Hard collinear gluon radiation and multiple scattering in a medium
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DOI：
10.1103/physrevd.85.014023
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发表时间：
2009-12
影响因子：
5
通讯作者：
A. Majumder
中科院分区：
文献类型：
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作者：
A. Majumder
在共线极限下，考虑了大核深度非弹性散射（DIS）中硬喷注的能量损失。特别地，计算了介质中多重散射引起的单胶子辐射截面。计算中进行了较高的扭曲计划，这是扩展到包括从多个横向散射的贡献上产生的夸克和辐射胶子。这些功率抑制贡献的前导长度增强部分被图示。这些图之间的各种干扰导致Landau-Pomeranchuk-Migdal（LPM）效应。我们从任意数量的散射中恢复校正，并分离出被硬尺度Q^{2}$的一个额外幂抑制的主要贡献。所发射的胶子前向动量分数y的所有幂都被保留。我们比较我们的结果与以前计算的单次散射每发射在较高的扭曲计划，以及与多个散射在其他计划。结果表明，在这种方法中，对双微分胶子产生截面的主导贡献（1/Q^2$）与单次散射计算结果等价，只要对末态夸克的横动量积分出去.我们评论的推广，这种形式主义的蒙特-卡罗例程。
The energy loss of hard jets produced in the Deep-Inelastic scattering (DIS) off a large nucleus is considered in the collinear limit. In particular, the single gluon emission cross section due to multiple scattering in the medium is calculated. Calculations are carried out in the higher-twist scheme, which is extended to include contributions from multiple transverse scatterings on both the produced quark and the radiated gluon. The leading length enhanced parts of these power suppressed contributions are resummed. Various interferences between such diagrams lead to the Landau-Pomeranchuk-Migdal (LPM) effect. We resum the corrections from an arbitrary number of scatterings and isolate the leading contributions which are suppressed by one extra power of the hard scale $Q^{2}$. All powers of the emitted gluon forward momentum fraction $y$ are retained. We compare our results with the previous calculation of single scattering per emission in the higher-twist scheme as well as with multiple scattering resummations in other schemes. It is found that the leading ($1/Q^2$) contribution to the double differential gluon production cross section, in this approach, is equivalent to that obtained from the single scattering calculation once the transverse momentum of the final quark is integrated out. We comment on the generalization of this formalism to Monte-Carlo routines.