Pion Production in High-Energy Proton-Proton Collisions

Abstract

We measured the differential production cross section for producing pions in 12.2-GeV/c $p\ensuremath{-}p$ collisions on lines of fixed ${P}_{1}$ and ${P}_{\ensuremath{\perp}}$ in the c.m. system. We found that $\frac{{d}^{2}\ensuremath{\sigma}}{d\ensuremath{\Omega}\mathrm{dp}}$ is maximum at ${P}_{1}=0$, in disagreement with our earlier result, which supported the two-center model. We have evidence that the earlier result is wrong. It also appears that in the c.m. system, $\frac{{d}^{2}\ensuremath{\sigma}}{d\ensuremath{\Omega}\mathrm{dp}}$ is factorable into functions of ${P}_{1}$ and ${P}_{\ensuremath{\perp}}$. In the ${P}_{\ensuremath{\perp}}$ dependence we found a very sharp forward peak of the form ${e}^{\ensuremath{-}15{{P}_{\ensuremath{\perp}}}^{2}}$.