Single-spin asymmetry of production in , Al, and Au collisions with transversely polarized proton beams at GeV

GeVでの横偏極陽子と陽子, アルミニウム, 金原子核との衝突における生成のシングルスピン非対称性

Aidala, C.*; 長谷川 勝一   ; 今井 憲一; 佐甲 博之   ; 佐藤 進  ; 谷田 聖   ; PHENIX Collaboration*; 他286名*

Aidala, C.*; Hasegawa, Shoichi; Imai, Kenichi; Sako, Hiroyuki; Sato, Susumu; Tanida, Kiyoshi; PHENIX Collaboration*; 286 of others*

We report the transverse single-spin asymmetries of production at forward and backward rapidity, , as a function of transverse momentum () and Feynman- (). The data analyzed were recorded by the PHENIX experiment at the Relativistic Heavy Ion Collider in 2015 from , Al, and Au collisions with transversely polarized proton beams at GeV. At this collision energy, single-spin asymmetries for heavy-flavor particle production of collisions provide access to the spin-dependent gluon distribution and higher-twist correlation functions inside the nucleon, such as the gluon Qiu-Sterman and trigluon correlation functions. Proton + nucleus collisions offer an excellent opportunity to study nuclear effects on the correlation functions. The data indicate negative asymmetries at the two-standard-deviation level in the Au data for GeV/ at both forward and backward rapidity, while in and Al collisions the asymmetries are consistent with zero within the range of experimental uncertainties.