J/ψ production at high transverse momenta in p+p and Cu+Cu collisions at sNN=200 GeV

Abstract

The STAR Collaboration at the Relativistic Heavy Ion Collider presents measurements of J/ψ → e+e- at midrapidity and high transverse momentum (pT > 5 GeV/c) in p+p and central Cu+Cu collisions at sNN=200 GeV. The inclusive J/ψ production cross section for Cu+Cu collisions is found to be consistent at high pT with the binary collision-scaled cross section for p+p collisions. At a confidence level of 97%, this is in contrast to a suppression of J/ψ production observed at lower pT. Azimuthal correlations of J/ψ with charged hadrons in p+p collisions provide an estimate of the contribution of B-hadron decays to J/ψ production of 13%±5%. © 2009 The American Physical Society.