Pion production in pN collisions near threshold

Abstract

Measurements of the pp→ppπ0 reaction at 310, 320, 340, 360, 400 and 425 MeV, and quasi-free pn→ppπ− production in pd collisions at 320 MeV have been carried out at the PROMICE/WASA facility at CELSIUS. The pp→ppπ0 differential cross sections have been parametrised and used to deduce the poorly known σ01 total cross section through the relation: σ01=2σ(pn→ppπ−)−σ(pp→ppπ0). Preliminary results show the σ01 to be of the order of 50% of the σ11 for the ppπ− excess energy between 8 and 40 MeV.