Pion production in proton-proton collisions in a covariant one-boson-exchange model

Motivated by the renewed interest in studying the pion production on nuclei with protons at few GeV incident energies, we investigate the pion production in proton-proton collisions over an energy range of 300 MeV to 2 GeV. Starting from a realistic one-boson-exchange model with parameters fitted to the amplitudes of the elastic nucleon-nucleon scattering, we perform fully covariant calculations for the total, double and triple differential cross sections of the p(p, n pi(+))p and p(p, p pi(0))p reactions. The calculations incorporate the exchange of pi, rho, omega, and sigma mesons and treat nucleon and delta isobar as intermediate states. We obtain a reasonably good agreement with the experimental data in the entire range of beam energies, The form of the covariant delta propagator, the cut-off parameter for the pi NN and pi N Delta vertex form factors and the energy dependence of the delta isobar decay width is investigated.