Open and Hidden Charm Production with the HERA-B Experiment

Abstract

Measurements of the suppression of the yield per nucleon and differential distributions of $J / ψ$ production for 920 GeV/c protons incident on heavy nuclear targets have been made with broad coverage in $p_T$ and negative coverage in $x_F$ of produced meson. Production ratios of $ψ(2S)$ to $J / ψ$ and $χ_c$ to $J / ψ$ have been measured with a high accuracy. The $D^+$ and $D^0$ production cross sections as well as $D^+$ to $D^0$ ratio have been obtained on one of the highest statistics available in proton nucleus experiments.