Proton-He elastic scattering: A phase-shift analysis by a separable potential model

Abstract

All the available experimental data (cross sections, projectile and target polarizations, polarization transfer coefficients) on p- 3 He elastic scattering up to ~10 MeV are analyzed on a unified basis in the framework of a separable potential model. This allows a phase-shift analysis which is model dependent, but is averaged over a wide energy interval (757 experimental points are reproduced by 27 model parameters). The calculations confirm some indications, already present in the literature, of a weak S-D tensor mixing, and strong singlet-triplet mixing in the P-states. Our conclusions are that probably the leading non-central effect is given by the coupling s 1 · l between the incident proton spin s 1 and the orbital angular momentum of relative motion. Finally, the phase shifts and observables are recalculated using the p- 3 He potential parameters, but switching off the Coulomb interaction. The results are compared with the (few) n- 3 H experimental cross sections of the literature, and the agreement is good, as expected on the basis of the charge-symmetry law.