2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/207245Using data collected by the HERA-B experiment, we have measured the fraction of Jψ's produced via radiative chi_c decays in interactions of 920 GeV protons with carbon and titanium targets. We obtained R_{χ_c} = 0.32 \pm 0.06_{stat} \pm 0.04_{sys} for the fraction of Jψfrom chi_c decays averaged over proton-carbon and proton-titanium collisions. This result is in agreement with previous measurements and is compared with theoretical predictions.16 pages, 5 figsHigh Energy Physics - Experimenttext