2013/12/31 by L. Adamczyk, J. K. Adkins, G. Agakishiev +370 · 106 citations
Physics and Astronomy · #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies #Physics #Quantum Chromodynamics and Particle Interactions #nucl-ex
paper · pdf · doi:10.1016/j.physletb.2014.06.028
published in Physics Letters B 735, 127-137 (Elsevier BV) · 13 pages, 7 figures
openalex publication_date 2014/06/16 · arxiv created 2015/01/21 · arxiv updated 2015/01/22 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We report measurements of ϒ meson production in p+p, d+Au, and Au+Au collisions using the STAR detector at RHIC. We compare the ϒ yield to the measured cross section in p+p collisions in order to quantify any modifications of the yield in cold nuclear matter using d+Au data and in hot nuclear matter using Au+Au data separated into three centrality classes. Our p+p measurement is based on three times the statistics of our previous result. We obtain a nuclear modification factor for ϒ(1S+2S+3S) in the rapidity range |y|<1 in d+Au collisions of RdAu=0.79±0.24(stat.)±0.03(syst.)±0.10(p+psyst.). A comparison with models including shadowing and initial state parton energy loss indicates the presence of additional cold-nuclear matter suppression. Similarly, in the top 10% most-central Au+Au collisions, we measure a nuclear modification factor of RAA=0.49±0.1(stat.)±0.02(syst.)±0.06(p+psyst.), which is a larger suppression factor than that seen in cold nuclear matter. Our results are consistent with complete suppression of excited-state ϒ mesons in Au+Au collisions. The additional suppression in Au+Au is consistent with the level expected in model calculations that include the presence of a hot, deconfined Quark–Gluon Plasma. However, understanding the suppression seen in d+Au is still needed before any definitive statements about the nature of the suppression in Au+Au can be made.