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arXiv 2303.09015hep-ph
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带电K介子和$Λ$超子在电子离子对撞机上产生的SIDIS过程中的Sivers不对称性

The Sivers asymmetry in charged Kaon and $Λ$ hyperon produced SIDIS process at electron ion colliders

Shuailiang Yang, Jianxi Song, Xiaoyu Wang, De-Min Li, Zhun Lu

摘要:

本文在次-前对数级横动量相关(TMD)分解的理论框架下,研究了带电K介子和$Λ$超子产生的SIDIS过程中存在$\sin (ϕ_h-ϕ_S)$调制的单横自旋不对称性.这种不对称性是由Sivers函数与产生强子的非极化碎裂函数$D_1$的卷积所贡献的。采用与Sivers函数密切相关的质子Qiu-Sterman函数的参数化方法,对中国电子离子对撞机(EIC)和中国电子离子对撞机(EicC)运动学区的Sivers不对称性进行了数值估算.采用非微扰Sudakov形状因子研究了TMD部分子分布函数的演化。结果表明,预测的Sivers不对称性$A_{UT}^{\sin (ϕ_h-ϕ_S)}$作为$x$、$z$和$P_{hT}$的函数,在EIC和EicC的运动学构型下都是相当大的.在末态中产生的带电K介子和$Λ$超子的奇异组分可以作为研究海夸克Sivers函数以及质子靶中味道依赖性的一个很有前途的探针。因此,利用未来的EIC设施来约束海夸克分布函数以及Sivers函数的广义普适性的有效性是重要的。

英文摘要:

We investigate the single transverse-spin asymmetry with a $\sin (ϕ_h-ϕ_S)$ modulation in the charged Kaon produced and in $Λ$ hyperon produced SIDIS process within the theoretical framework of transverse momentum dependent (TMD) factorization at the next-to-leading-logarithmic order. The asymmetry is contributed by the convolution of Sivers function and the unpolarized fragmentation function $D_1$ for the produced hadron. The parametrization for the proton Qiu-Sterman function, which is closely related to the Sivers function, is adopted to numerically estimate the Sivers asymmetry at the kinematical region of Electron Ion Collider (EIC) and Electron Ion Collider in China (EicC). The TMD evolution of the TMD parton distribution functions are considered by employing the nonperturbative Sudakov form factor. It is found that the predicted Sivers asymmetries $A_{UT}^{\sin (ϕ_h-ϕ_S)}$ as functions of $x$, $z$ and $P_{hT}$ are sizable at the kinematical configurations of both EIC and EicC. The strange constituent of the produced charged Kaon and $Λ$ hyperon in the final state can be a promising probe of the sea quark Sivers function as well as the flavor dependence in the proton target. Therefore, it is important to utilize the future EIC facilities to constrain the sea quark distribution functions as well as the validity of the generalized universality of the Sivers function.

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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