sup 4 He(. pi. ,. pi. prime p ) sup 3 He reaction near the P sub 33. pi. -nucleon resonance

Inclusive and exclusive spectra of the {sup 4}He({pi},{pi}{prime},{ital p}) reaction were measured with {pi}{sup +} and {pi}{sup {minus}} at {ital T}{sub {pi}}=140 MeV and {theta}{sub {pi}}=40{degree}, and at 180 MeV and 30{degree}, 40{degree}, 60{degree}, and 80{degree} using the EPICS system at LAMPF in coincidence with elastic plastic scintillators. The inclusive spectra yield cross section ratios {ital R}{sub {pi}}={sigma}({pi}{sup +})/{sigma}({pi}{sup {minus}})=1.1{plus minus}0.1 at both {ital T}{sub {pi}} and all {theta}{sub {pi}}. Exclusive spectra were obtained between {sup 4}He{sup *} excitation energies {ital E}{sub {ital x}}=21.5 and 45.0 MeV. Angular correlation functions for ({pi},{pi}{prime},{ital p}) were extracted at {ital T}{sub {pi}}=180 MeV at the four pion angles for selected regions of {ital E}{sub {ital x}}. The ({pi}{sup +},{pi}{sup +{prime}}{ital p}) angular correlations show a distinct peak near the free proton knockout angle; however, the ({pi}{sup {minus}},{pi}{sup {minus}{prime}}{ital p}) data show either a flat distribution or a mininum near that angle. Calculations, using a distorted wave impulse approximation (DWIA) code which models the ({pi},{pi}{prime}{ital p}) reaction as a pion-induced proton knockout, predict peaks in the angular correlation functions in the quasifree knockout direction and reproduce quite well the ({pi}{sup +},{pi}{sup +{prime}}{ital p}) data above {ital E}{sub {ital x}}=30 MeV. However, these calculations domore » not resemble the ({pi}{sup {minus}},{pi}{sup {minus}{prime}}{ital p}) data at any excitation energy.« less