PION PRODUCTION IN NEUTRON-PROTON COLLISIONS

Abstract

Publisher Summary This chapter discusses the pion production in neutron–proton collisions. The 800 MeV neutron beam at Los Alamos Meson Physics Facility allows to investigate a particularly interesting theoretical situation. The Mandelstam model probably fails to describe pion production in this region. Two of the basic assumptions of the model, that only a few partial waves are present and that the production matrix elements are independent of energy, are expected to fail at 700–800 MeV. Another basic tenet of the theory is that pion production takes place through the resonance. A search for nonresonant contributions would provide a stringent test of the model. The one pion exchange model valid from about 800 to 1500 MeV, fails in the same region because of the neglect of nucleon–nucleon final state interactions. The np data may be used to test these models in the region of overlap and, along with new elastic scattering data, should provide the input for calculations of np phase shifts in the inelastic region.