Measurement of the relative yields of to mesons produced at forward and backward rapidity in , Al, Au, and He+Au collisions at GeV

GeVでの陽子-陽子、陽子-アルミニウム、陽子-金、ヘリウム3-金衝突における前方および後方ラピディティーでのとの生成比の測定

Adare, A.*; 長谷川 勝一   ; 今井 憲一; 佐甲 博之   ; 佐藤 進  ; 谷田 聖   ; PHENIX Collaboration*; 他361名*

Adare, A.*; Hasegawa, Shoichi; Imai, Kenichi; Sako, Hiroyuki; Sato, Susumu; Tanida, Kiyoshi; PHENIX Collaboration*; 361 of others*

The PHENIX Collaboration has measured the ratio of the yields of to mesons produced in , Al, Au, and He+Au collisions at GeV over the forward and backward rapidity intervals . We find that the ratio in collisions is consistent with measurements at other collision energies. In collisions with nuclei, we find that in the forward (-going or He-going) direction, the relative yield of mesons to mesons is consistent with the value measured in collisions. However, in the backward (nucleus-going) direction, the meson is preferentially suppressed by a factor of . This suppression is attributed in some models to the breakup of the weakly bound meson through final-state interactions with comoving particles, which have a higher density in the nucleus-going direction. These breakup effects may compete with color screening in a deconfined quark-gluon plasma to produce sequential suppression of excited quarkonia states.