He4(p,2p)H3reaction at intermediate energies

Abstract

The $^{4}\mathrm{He}$($p$,$2p$)$^{3}\mathrm{H}$ reaction has been studied at 250, 350, and 500 MeV using coplanar symmetric and asymmetric geometries. The data are presented as energy-sharing spectra, coplanar symmetric angular distributions, and quasifree angular distributions. A comparison with distorted wave impulse approximation calculations indicates reasonable agreement for small recoil momenta ($q\ensuremath{\lesssim}150$ MeV/c). For larger recoil momenta, the distorted-wave impulse approximation calculations increasingly underestimate the data. The discrepancies are substantially reduced by inclusion of a spin-orbit term in the optical potential used to generate the distorted waves. Improvements of the single particle wave function for the struck nucleon influence the calculations to a lesser degree. The remaining discrepancies at large recoil momenta may, in part, be ascribed to multiple scattering effects and exchange processes not included in the standard distorted-wave impulse approximation.NUCLEAR REACTIONS $^{4}\mathrm{He}$($p$,$2p$)$^{3}\mathrm{H}$; measured $\frac{{d}^{3}\ensuremath{\sigma}}{(d{\ensuremath{\Omega}}_{3}d{\ensuremath{\Omega}}_{1}d{T}_{3})}$, 250, 350, 500 MeV, energy sharing spectra, coplanar symmetric angular distributions, quasifree angular distributions; comparison with DWIA calculations.