论文标题
Sidis和Compass的Drell-Yan过程中的横向动量加权的Sesivers不对称
Transverse momentum weighted Sivers asymmetries in SIDIS and Drell-Yan processes at COMPASS
论文作者
论文摘要
我们研究了具有横向极化质子目标的过程中的横向动量加权的不对称性，包括$ \ frac {p_ {ht}} {zm_p} \ sin（ϕ_h-- ϕ_s）$在半含量的内龙（Seidiiss）中加权的hadron中（ϕ_h-ϕ_s）$加权不对称（SIDIS），以及SIDISSISISISISISISISISISISISISISISISISIDIS）。 $ \ frac {q_t} {m_p} \ sin（ϕ_s）$ in $π^ - p $ drell-yan过程中加权不对称。由于横向动量的整合，加权不对称可以表示为横向动量依赖（TMD）Parton分布函数（PDFS）和片段化函数（FFS）的横向肌的乘积。使用质子的Sivers功能的参数化，质子和质子的未核糖PDF以及带电的强子的未偏振FF，我们介绍了Sidis和Drell-Yan过程的加权SIVERS不对称的数值计算，并将其与实验数据相比。我们发现，我们对SIDIS过程中加权士兵不对称的预测与最近的指南针测量一致。由于Compass Drell-Yan程序的初步数据的不确定性相对较大，因此需要高精度的实验数据来测试Sidis和Drell-Yan过程之间Sivers功能的标志变化属性，并限制Sea Quark Sivers功能。
We investigate the transverse momentum weighted Sivers asymmetries in the processes with transversely polarized proton target, including the $\frac{P_{hT}}{zM_p}\sin (ϕ_h-ϕ_S)$ weighted asymmetry in charged hadron production in semi-inclusive deeply inelastic scattering (SIDIS) and the $\frac{q_T}{M_p}\sin (ϕ_S)$ weighted asymmetry in $π^- p$ Drell-Yan process. Due to the integration over the transverse momentum, the weighted 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, and compare them with experimental data. We find that our prediction on the weighted Sivers asymmetry in SIDIS process is in agreement with the recent COMPASS measurement. Due to the relatively large uncertainties of the preliminary data from COMPASS Drell-Yan program, high precision experimental data are 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.
