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

Abstract

The three-body final-state reaction of charged single-pion production, $pp\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}\mathrm{pn}$, and that for charged double-pion production, $pp\ensuremath{\rightarrow}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\pi}}^{\ensuremath{-}}pp$, have been studied at ${T}_{P}=800$ MeV by measuring the momentum spectra for ${\ensuremath{\pi}}^{+}$ and ${\ensuremath{\pi}}^{\ensuremath{-}}$ 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.NUCLEAR REACTIONS Pion production in the two-nucleon system: $pp\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}\mathrm{pn}$, $pp\ensuremath{\rightarrow}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}pp$; ${E}_{p}=800$, $\ensuremath{\theta}=16.5\ifmmode^\circ\else\textdegree\fi{}\ensuremath{-}60\ifmmode^\circ\else\textdegree\fi{}$. Observed $\frac{{d}^{2}\ensuremath{\sigma}}{d\ensuremath{\Omega}d{q}_{\ensuremath{\pi}}}$. Peripheral model analyses.