| Abstract: | Heavy quarkonia are observed to be suppressed in relativistic heavy ion
collisions relative to their production in p+p collisions scaled by the number
of binary collisions. In order to determine if this suppression is related to
color screening of these states in the produced medium, one needs to account
for other nuclear modifications including those in cold nuclear matter. In this
paper, we present new measurements from the PHENIX 2007 data set of J/psi
yields at forward rapidity (1.2<|y|<2.2) in Au+Au collisions at sqrt(s_NN)=200
GeV. The data confirm the earlier finding that the suppression of J/psi at
forward rapidity is stronger than at midrapidity, while also extending the
measurement to finer bins in collision centrality and higher transverse
momentum (pT). We compare the experimental data to the most recent theoretical
calculations that incorporate a variety of physics mechanisms including gluon
saturation, gluon shadowing, initial-state parton energy loss, cold nuclear
matter breakup, color screening, and charm recombination. We find J/psi
suppression beyond cold-nuclear-matter effects. However, the current level of
disagreement between models and d+Au data precludes using these models to
quantify the hot-nuclear-matter suppression. |
REGISTER
Did you like this article? 
