Download or read book J/PSI Production Via Chi Sub C Decays in Fixed Target Proton-nucleus Collisions written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In the last decades, the mechanism of production of heavy quarkonium states has been the subject of research efforts involving both theoretical and experimental developments. Even though the predictions of the presently accepted models differ, the amount of experimental data does not allow for a determination of the best suited theory. The particular case of charmonium production in hadron collisions is an attractive test case as the charm is heavy enough to allow for perturbative calculations of the production process, and yet the cross sections involved are large enough so that events can be measured with good statistics. The data collected at the HERA-B detector after the HERA-II upgrade is analyzed and used to estimate the fraction of J/Psi produced via radiative Chi sub c decays. The result is compared to theoretical predictions and it is found to agree with calculations based on the color evaporation model and with the calculations using the non-relativistic quantum chromodynamics model.