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arXiv 1701.05660hep-ph
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在大$z$极限下碎裂成射流

Fragmentation to a jet in the large $z$ limit

Lin Dai, Chul Kim, Adam K. Leibovich

摘要:

在大$z$极限下,考虑部分子碎裂成小半径$R$的喷流,其中$z$是喷流能量与母部分子能量的比值.在相空间的这个区域中,$R$和$1-z$都可能出现大的微扰,为了有一个定义良好的微扰展开,需要重新计算。利用软共线有效理论,我们研究了在这个端点区域的射流破碎函数。我们推导出这个对象的分解定理,分离共线和共线软模式。这允许同时使用重整化群演化对$\ln R$和$\ln(1-z)$进行重正化。我们的结果有效的下一个领先的对数阶的全球Sudakov的算法。我们还讨论了非全球性的可能性,应该出现在两个循环,并给出其大小的估计。

英文摘要:

We consider the fragmentation of a parton into a jet with small radius $R$ in the large $z$ limit, where $z$ is the ratio of the jet energy to the mother parton energy. In this region of phase space, large logarithms of both $R$ and $1-z$ can appear, requiring resummation in order to have a well defined perturbative expansion. Using soft-collinear effective theory, we study the fragmentation function to a jet (FFJ) in this endpoint region. We derive a factorization theorem for this object, separating collinear and collinear-soft modes. This allows for the resummation using renormalization group evolution of the logarithms $\ln R$ and $\ln(1-z)$ simultaneously. We show results valid to next-to-leading logarithmic order for the global Sudakov logarithms. We also discuss the possibility of non-global logarithms that should appear at two-loops and give an estimate of their size.

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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