Polarized hyperon production in single-inclusive electron-positron annihilation at next-to-leading order
Polarized hyperon production in single-inclusive electron-positron annihilation at next-to-leading order
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DOI：
10.1007/jhep01(2019)111
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发表时间：
2018-10
影响因子：
5.4
通讯作者：
L. Gamberg;Z. Kang;D. Pitonyak;M. Schlegel;S. Yoshida
中科院分区：
文献类型：
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作者：
L. Gamberg;Z. Kang;D. Pitonyak;M. Schlegel;S. Yoshida
本文研究了正负电子湮灭中极化Λ超子的产生。我们特别感兴趣的是非极化入射电子-正电子对的横截面的自旋依赖性。在高能量下，这个过程可以用共线扭曲-3框架来描述，其中部分子到横向极化的Λ-超子的强子化跃迁可以用共线扭曲-3碎裂矩阵元来表示。我们计算了微扰QCD中的硬部分子截面和干涉项，达到次领先阶精度。我们发现QCD运动方程在我们的分析中起着至关重要的作用。作为一个副产品，假设的有效性的QCD分解的twist-3观测在次领先的顺序，我们推导出相应的twist-3碎裂矩阵元的演化方程。
We study the production of polarized Λ-hyperons in electron-positron annihilation. We are particularly interested in the transverse-spin dependence of the cross section for unpolarized incident electron-positron pairs. At high energies this process may be described in the collinear twist-3 framework, where the hadronization transition of partons into a transversely polarized Λ-hyperon can be written in terms of collinear twist-3 fragmentation matrix elements. We calculate the hard partonic cross sections and interference terms in perturbative QCD to next-to-leading order accuracy. We find that the QCD equation of motion plays a crucial role in our analysis. As a byproduct, assuming the validity of QCD factorization for twist-3 observables at next-to-leading order, we derive the evolution equation for the relevant twist-3 fragmentation matrix element.