论文标题
电子正电子歼灭过程中的强体对前后不对称
The hadron pair forward-backward asymmetry in the electron positron annihilation process
论文作者
论文摘要
前向后不对称是一个重要的可测量量，可以独立地确定费米子的中性耦合。在本文中，我们通过在半封装电子位置歼灭过程中计算这种强子对的不对称性，从党级将不对称性的定义从党级扩展到了辐射水平。半包含的意味着除了强子对外，还测量了背对背喷气机。由于分解定理的局限性，我们通过应用共线膨胀形式主义将此过程计算为领先的twist-4水平。获得差分横截面后，我们计算前进的不对称性，并以相应的二辐射片段化函数来显示它们。引入了二 - 二龙片段化函数，以描述片段化过程中的强子对生产。通过函数的可用参数化，我们提出了前回答不对称的数值估计。另一方面，向前偏离不对称的测量将严格限制二二体碎片函数的参数化。我们还提出了Twist-4 Di-Hadron碎片函数的数值估计，以说明它们的贡献。
The forward-backward asymmetry is an important measurable quantity which can enable independent determination of the neutral-current couplings of fermions. In this paper, we extend the definition of the asymmetry from the partonic level to the hadronic level by calculating this asymmetry of the hadron pair in the semi-inclusive electron position annihilation process. Semi-inclusive implies that a back-to-back jet is also measured in addition to the hadron pair. Due to the limitation of the factorization theorem, we calculate this process up to leading order twist-4 level by applying the collinear expansion formalism. After obtaining the differential cross section, we calculate the forward-backward asymmetries and show them in terms of the corresponding di-hadron fragmentation functions. Di-hadron fragmentation functions are introduced to describe the hadron pair productions in the fragmentation process. With available parameterization of the functions, we present a numerical estimation of the forward-backward asymmetry. On the flip side, measurements of the forward-backward asymmetry would give strict restrictions of parameterizations of the di-hadron fragmentation functions. We also present a numerical estimation of the twist-4 di-hadron fragmentation functions in order to illustrate their contributions.
