Open and Hidden Charm Production with the HERA-B Experiment

TL;DR

This paper reports on measurements of charmonium and open charm production in proton-nucleus collisions at 920 GeV/c, providing detailed data on suppression, production ratios, and cross sections with high precision.

Contribution

It presents new high-precision measurements of $J/\psi$, $\psi(2S)$, $\chi_c$, and open charm production in proton-nucleus interactions at 920 GeV/c.

Findings

Measured suppression of $J/\psi$ yield per nucleon.

Determined production ratios of $\psi(2S)$ to $J/\psi$ and $\chi_c$ to $J/\psi$.

Obtained high-statistics open charm cross sections.

Abstract

Measurements of the suppression of the yield per nucleon and differential distributions of $J / \psi$ 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 $\psi(2S)$ to $J / \psi$ and $\chi_c$ to $J / \psi$ 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.