2012/11/29 by ZEUS Collaboration · 1 citation
Physics and Astronomy · #81V05 #FOS: Physical sciences #High Energy Physics - Experiment (hep-ex) #hep-ex #msc:81V05
paper · pdf · doi:10.48550/arxiv.1211.6946
27 pages, 10 figures
arxiv created 2012/12/20 · arxiv updated 2012/12/21
The cross sections for inelastic photoproduction of J/psi and psiprime mesons have been measured in ep collisions with the ZEUS detector at HERA, using an integrated luminosity of 468 pb-1 collected in the period 1996--2007. The psiprime to J/psi cross section ratio was measured in the range 0.55 < z < 0.9 and 60 < W < 190 GeV as a function of W, z and pT. Here W denotes the photon-proton centre-of-mass energy, z is the fraction of the incident photon energy carried by the meson and pT is the transverse momentum of the meson with respect to the beam axis. The J/psi cross sections were measured for 0.1 < z < 0.9, 60 < W < 240 GeV and pT > 1 GeV. Theoretical predictions within the non-relativistic QCD framework including NLO colour--singlet and colour--octet contributions were compared to the data, as were predictions based on the kT--factorisation approach.