DESY-HERA. Measurement of the exclusive photoproduction of J/PSI mesons in the reaction GAMMA P --& gt; J/PSI P in the kinematic range of W from 20 to 290 GeV, where W is the photon-proton c.m. energy. The data come from muon decays of J/P SI collected during 1996 and 1997 with an integrated luminosity of 38 pb-1 and electron decays of J/PSI collected during 1999 and 2000 with an integrated luminosity of 55 pb-1. Both data sets come from 27.5 GeV positrons colliding with 820 GeV protons for the muon data set and 920 GeV protons for the electron data set.Allcross sections are corrected for the respective branching ratios of the J/PS I decay. Numerical values supplied by A. Bruni.
|Date made available||2002|