NN→NNπ reaction near threshold in a covariant one-boson-exchange model

We calculate the cross sections for the p(p,nπ+)p and p(p,pπ0)p reactions for proton beam energies near threshold in a covariant one-boson-exchange model, which incorporates the exchange of π, ρ, σ and ω mesons, treats both nucleon and delta isobar as intermediate states. The final state interaction effects are included within the Watsonʹs theory. Within this model the ω and σ meson exchange terms contribute significantly at these energies, which, along with other meson exchanges, make it possible to reproduce the available experimental data for the total as well as differential cross sections for both the reactions. The cross sections at beam energies ≤300 MeV are found to be almost free from the contributions of the Δ isobar excitation.