Charmed particles production in pA-interactions at 70 GeV

TL;DR

This paper reports on the measurement of charm particle production in proton-nucleus interactions at 70 GeV, providing experimental cross sections, lifetimes, and mass data that challenge existing QCD predictions.

Contribution

It presents new experimental data on charm production cross sections near threshold energies, including their A-dependencies and comparison with theoretical models.

Findings

Measured total open charm cross section is 7.1 μb/nucleon, exceeding QCD predictions.

Lifetimes and masses of charm particles agree with PDG data.

Yields of charm particles vary with energy and target material.

Abstract

The results of the SERP-E-184 experiment at the U-70 accelerator (IHEP, Protvino) are presented. Interactions of the 70 GeV proton beam with carbon, silicon and lead targets were studied to detect decays of charmed $D^0$, $\bar D^0$, $D^+$, $D^-$ mesons and $\Lambda_c^+$ baryon near their production threshold. Measurements of lifetimes and masses have shown a good agreement with PDG data. The inclusive cross sections of charm production and their A-dependencies have been obtained. The yields of these particles are compared with the theoretical predictions and the data of other experiments. The measured cross section of the total open charm production $\sigma(c\bar c) = 7.1 \pm 2.3(stat) \pm 1.4(syst)$ $\mu$b/nucleon at the collision c.m. energy $\surd s$ = 11.8 GeV is well above the QCD model predictions. The contributions of different kinds of charmed particles to the total cross section of the open charm production in proton-nucleus interactions vary with energy.