Nuclear dependence of the transverse single-spin asymmetry in the production of charged hadrons at forward rapidity in polarized , Al, and Au collisions at GeV

GeVでの, AlおよびAu衝突における前方荷電粒子生成のシングルスピン非対称性の原子核依存性

Aidala, C.*; 長谷川 勝一   ; 今井 憲一; 佐甲 博之   ; 佐藤 進  ; 谷田 聖   ; PHENIX Collaboration*; 他296名*

Aidala, C.*; Hasegawa, Shoichi; Imai, Kenichi; Sako, Hiroyuki; Sato, Susumu; Tanida, Kiyoshi; PHENIX Collaboration*; 296 of others*

We report on the nuclear dependence of transverse single-spin asymmetries (TSSAs) in the production of positively-charged hadrons in polarized , Al and Au collisions at GeV. The measurements have been performed at forward rapidity () over the range of GeV and . We observed a positive asymmetry for positively-charged hadrons in collisions, and a significantly reduced asymmetry in + collisions. These results reveal a nuclear dependence of charged hadron in a regime where perturbative techniques are relevant. These results provide new opportunities to use A collisions as a tool to investigate the rich phenomena behind TSSAs in hadronic collisions and to use TSSA as a new handle in studying small-system collisions.