论文标题
$ E^+E^ - $ HADRONIC生产过程中的普遍性破坏效果
Universality-breaking effects in $e^+e^-$ hadronic production processes
论文作者
论文摘要
最近的Belle测量值提供了$ E^+E^ - $ nihilations的单个强子产生的横截面，相对于推力轴的推力和强子横向动量差异。由于过程依赖性软因子引起的普遍性破坏效应使得很难将此横截面与$ e^+e^ - $ nihillations中对应于强子生产的人相关联，其中可以应用横向动量依赖（TMD）因素。这两个横截面之间的对应关系在共线以及TMD方法中的柯林斯 - 索特人分解的框架中检查。我们提出了一个方案，该方案允许在1-HADRON和2-HADRON过程中定义的TMD Parton密度，在软和界线部分中整齐地分离，将非扰动项与可以触及扰动计算的贡献中的非扰动项。速度差异的正则化引入了截止性，其任意性将通过紧密让人联想到仪表转换的机制来适当地重吸收。通过这种方式，我们恢复了对TMD物理学进行全球现象学研究的可能性，同时分析了属于不同强子类别的数据。
Recent BELLE measurements provide the cross section for single hadron production in $e^+e^-$ annihilations, differential in thrust and in the hadron transverse momentum with respect to the thrust axis. Universality breaking effects due to process-dependent soft factors make it very difficult to relate this cross sections to those corresponding to hadron-pair production in $e^+e^-$ annihilations, where transverse momentum dependent (TMD) factorization can be applied. The correspondence between these two cross sections is examined in the framework of the Collins-Soper-Sterman factorization, in the collinear as well as in the TMD approach. We propose a scheme that allows to relate the TMD parton densities defined in 1-hadron and in 2-hadron processes, neatly separating, within the soft and collinear parts, the non-perturbative terms from the contributions that can be calculated perturbatively. The regularization of rapidity divergences introduces cut-offs, the arbitrariness of which will be properly reabsorbed by means of a mechanism closely reminiscent of a gauge transformation. In this way, we restore the possibility to perform global phenomenological studies of TMD physics, simultaneously analyzing data belonging to different hadron classes.
