π+−pInteractions in the Energy Range around 500 Mev

A hydrogen-filled diffusion cloud chamber investigation of ${\pi }^{+}-p$ interactions in the energy range around 500 Mev is reported. The elastic scattering angular distribution, based on a total of 180 events, is analyzed using only $s$ and $p$ waves, and also using $s$ and $p$ waves with a $d$-wave interference term. Phase shifts are presented and ambiguities are discussed. The $d$-wave contribution is small. The elastic cross section is used to compute the real part of the forward coherent scattering amplitude. The latter is in good agreement with that predicted by the dispersion relations. Inelastic production sets in at about 300 Mev. Eighteen inelastic events were found; 7 were $p$+0, 7 were $n^{++}$, and 4 were unidentifiable. Inelastic processes are discussed in terms of various models.