J/psi Production at High Transverse Momenta in P+p and Cu+Cu Collisions at Sqrt SNN

Book excerpt: The STAR collaboration at RHIC presents measurements of J/[psi] → e+e− at mid-rapidity and high transverse momentum (p{sub T} > 5 GeV/c) in p+p and central Cu+Cu collisions at √sNN = 200 GeV. The inclusive J/[psi] production cross section for Cu+Cu collisions is found to be consistent at high p{sub T} with the binary collision-scaled cross section for p+p collisions, in contrast to previous measurements at lower p{sub T}, where a suppression of J/[psi] production is observed relative to the expectation from binary scaling. Azimuthal correlations of J/[psi] with charged hadrons in p+p collisions provide an estimate of the contribution of B-meson decays to J/[psi] production of 13% ± 5%.