Proton-induced nucleon knockout from polarized 3He at 220 MeV.

Abstract

A high pressure polarized $^{3}\mathrm{He}$ gas target has been used to measure spin observables and absolute cross sections for (p\ensuremath{\rightarrow},2p) and (p\ensuremath{\rightarrow},pn) nucleon knockout in quasielastic kinematics at 220 MeV. The neutron knockout spin observables exhibit large deviations from plane wave impulse approximation (PWIA) calculations and show the importance of rescattering corrections. At this energy, the proton knockout spin observables differ slightly from PWIA calculations, especially at low energy transfers (\ensuremath{\omega}), but this discrepancy may be resolved when final state interactions between nucleons of the two-body recoil scattering state are included. The large rescattering effects observed in the (p\ensuremath{\rightarrow},pn) results may have implications for experiments which consider polarized $^{3}\mathrm{He}$ as a polarized neutron.