학술논문
Measurement of the relative yields of ψ(2S) to ψ(1S) mesons produced at forward and backward rapidity in p+p, p+Al, p+Au, and He 3 +Au collisions at s NN =200 GeV
Document Type
Author
Adare, A; Aidala, C.; Ajitanand, N. N.; Akiba, Y.; Alfred, M.; Andrieux, V.; Aoki, K.; Apadula, N; Asano, H.; Ayuso, Carmen; Azmoun, B.; Babintsev, V.; Bai, M; Bandara, N. S.; Bannier, B; Barish, K N; Bathe, S; Bazilevsky, A; Beaumier, M.; Beckman, S.; Belmont, R; Berdnikov, A; Berdnikov, Y.; Blau, D. S.; Boer, M.; Bok, J S; Bownes, E. K.; Boyle, K; Brooks, M L; Bryslawskyj, J.; Bumazhnov, V.; Butler, Christopher C.; Campbell, S.; Canoa Roman, V.; Cervantes, R.; Chen, C. H.; Chi, C Y; Chiu, M; Choi, I J; Choi, J B; Chujo, T.; Citron, Z.; Connors, M.; Cronin, N.; Csanád, M; Csörgo, T.; Danley, T. W.; Datta, A.; Oskarsson, A.; Silvermyr, D.
Source
Physical Review C: covering nuclear physics. 95(3)
Subject
Language
English
ISSN
2469-9985
Abstract
The PHENIX Collaboration has measured the ratio of the yields of ψ(2S) to ψ(1S) mesons produced in p+p, p+Al, p+Au, and He3+Au collisions at sNN=200 GeV over the forward and backward rapidity intervals 1.2<|y|<2.2. We find that the ratio in p+p collisions is consistent with measurements at other collision energies. In collisions with nuclei, we find that in the forward (p-going or He3-going) direction, the relative yield of ψ(2S) mesons to ψ(1S) mesons is consistent with the value measured in p+p collisions. However, in the backward (nucleus-going) direction, the ψ(2S) meson is preferentially suppressed by a factor of ∼2. This suppression is attributed in some models to the breakup of the weakly bound ψ(2S) 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.