Comparison of Proton Momentum Spectra in Proton-Proton Collisions Involving Pion and Kaon Production

Striking similarities are found in the proton momentum spectra involving pion and kaon production processes. Except for the falloff near the kinematical limits, the longitudinal-momentum distributions are isotropic. In the transverse-momentum spectra, a sharp break near ${P_{\perp }}^2=0.2\mathrm{} {\left(\frac{\mathrm{GeV}}{c}\right)}^2$ is observed in both processes. The breaks are attributed to the production and decay of peripherally produced nucleon resonances.