Production of a0-mesons in the reactions πN↦a0N and pp↦da0+ at GeV energies

Abstract:We investigate the reactions πN↦a0N and pp↦da0+ near threshold and at medium energies. An effective Lagragian approach and the Regge pole model are applied to analyze different contributions to the cross-section of the reaction πN↦a0N. These results are used to calculate the differential and total cross-sections of the reaction pp↦da0+ within the framework of the two-step model in which two nucleons produce an a0-meson via π-meson exchange and fuse to a deuteron. The necessity of new measurements on a0 production and branching fractions (of its decay to the K and πη channels) is emphasized for clarifying the a0 structure. Detailed predictions for the reaction pp→da0+ are presented for the energy regime of the proton synchrotron COSY-Jülich.