Single and double pion production from 800 MeV proton-proton collisions

The three-body final-state reaction of charged single-pion production, pp..--> pi../sup +/pn, and that for charged double-pion production, pp..--> pi../sup -/..pi../sup +/pp, have been studied at T/sub P/=800 MeV by measuring the momentum spectra for ..pi../sup +/ and ..pi../sup -/ emitted from proton-proton collisions. The momentum spectra for single-pion production are fit with the peripheral model calculations of VerWest, and a similar model by one of us is discussed. The spectra for double-pion production follow an extrapolation of the Lindenbaum and Sternheimer model from higher energies toward threshold. This result is in disagreement with the results of Cochran et al.