Open and Hidden Charm Production in 920 GeV Proton-Nucleus Collisions

The HERA-B collaboration has studied the production of charmonium and open charm states in collisions of 920 GeV protons with wire targets of different materials. The acceptance of the HERA-B spectrometer covers negative values of xF up to xF=−0.3 and a broad range in transverse momentum from 0.0 to 4.8GeV/c. The studies presented in this paper include J/ψ differential distributions and the suppression of J/ψ production in nuclear media. Furthermore, production cross sections and cross section ratios for open charm mesons are discussed.