Naslov
Suppression of Υ production in d+Au and Au+Au collisions at √sNN =200 GeV

Autori
Adamczyk, L. ; ... ; Planinić, Mirko ; ... ; Poljak, Nikola ; ... Zyzak, M.

Izvornik
Physics letters. B (0370-2693) 735 (2014); 127-137

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
suppresion; upsilon; STAR

Sažetak
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+p syst.) . 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 View the MathML source , 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.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

Napomena
STAR Collaboration.

POVEZANOST RADA