We investigate the transverse momentum weighted Sivers asymmetries in the processes with transversely polarized proton target, including the weighted asymmetry in charged hadron production in semi-inclusive deeply inelastic scattering (SIDIS) and the weighted asymmetry in Drell-Yan process. These asymmetries can be expressed as the product of the transverse-moments of the transverse momentum dependent (TMD) parton distribution functions (PDFs) and fragmentation functions (FFs). Using the parametrization for the Sivers function of the proton, the unpolarized PDFs of proton and pion, and the unpolarized FF of charged hadron, we present the numerical calculation for weighted Sivers asymmetries in SIDIS and Drell-Yan processes at the kinematics of COMPASS. We find that our prediction for the SIDIS process is in agreement with the recent COMPASS measurement. Recent new high-statistics data of Sivers asymmetry measured in SIDIS process and Drell-Yan process from COMPASS favored the sign change of Sivers function. High-precision experimental data of weighted asymmetries are still needed to test the sign change property of the Sivers function between SIDIS and Drell-Yan processes and to constrain the sea quark Sivers function.

中文翻译：

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COMPASS 的 SIDIS 和 Drell-Yan 过程中的横向动量加权 Sivers 不对称性


我们研究了横向极化质子靶过程中的横向动量加权Sivers不对称性，包括半包容深度非弹性散射（SIDIS）中带电强子产生的加权不对称性和Drell-Yan过程中的加权不对称性。这些不对称性可以表示为横向动量相关 (TMD) 部分子分布函数 (PDF) 和碎片函数 (FF) 的横向力矩的乘积。利用质子 Sivers 函数的参数化、质子和介子的非极化 PDF 以及带电强子的非极化 FF，我们提出了 COMPASS 运动学上 SIDIS 和 Drell-Yan 过程中加权 Sivers 不对称性的数值计算。我们发现我们对 SIDIS 过程的预测与最近的 COMPASS 测量结果一致。最近在 COMPASS 的 SIDIS 过程和 Drell-Yan 过程中测得的 Sivers 不对称性的新高统计数据有利于 Sivers 函数的符号变化。仍需要高精度的加权不对称实验数据来测试SIDIS和Drell-Yan过程之间Sivers函数的符号变化特性以及对海夸克Sivers函数的约束。