标题：Measurement of longitudinal single-spin asymmetry for W±production in polarized proton+proton collisions at STAR
作者机构：[Xu, Qinghua ] School of Physics, Key Laboratory of Particle Physics and Particle Irradiation (MoE), Shandong University, Jinan, Shandong; 250100, Chi 更多
会议名称：25th International Workshop on Deep-Inelastic Scattering and Related Subjects, DIS 2017
会议日期：April 3, 2017 - April 7, 2017
来源：Proceedings of Science
摘要：The sea quark contribution to the nucleon spin is an important piece for a complete understanding of the nucleon spin structure. The production of W bosons in longitudinally polarized p+ p collisions at RHIC provides an unique probe for the sea quark polarization, through the parityviolating single-spin asymmetry, AΛ. At the STAR experiment, W bosons through the leptonic decay channel W → en can be effectively determined with the Electromagnetic Calorimeters and Time Projection Chamber at mid-rapidity. The previous STAR measurements of AΛ for W boson production from datasets taken in 2011 and 2012, have provided significant constraints on the helicity distribution functions of ū and d quarks. In 2013 the STAR experiment collected p+ p data with an integrated luminosity of about 300 pb-1at √s = 510 GeV with an average beam polarization of about 56%, which is more than three times larger than the total integrated luminosity of previous years. The preliminary results of W-boson AΛfrom 2013 data sample will be presented.
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