Phase-Shift Analysis forHe3(p, p)He3

Abstract

A phase-shift analysis based on the scattering and polarization data for the reaction ${\mathrm{He}}^3(p, p){\mathrm{He}}^3$ has been made for proton energies between 1.0 and 11.5 MeV. The singlet and triplet $S$-wave phase shifts are found to be negative and approximately equal; they are in good agreement with the resonating-group calculations of Bransden and Robertson. The $P$-wave phase shifts are positive and increase with energy; a single-level parametrization of these phase shifts indicates the possible presence of triplet states with $J^{\pi }=2^{-}, 1^{-}, 0^{-}$ at center-of-mass energies 4.74, 6.15, and 7.94 MeV above the $p$ + ${\mathrm{He}}^3$ threshold. All three levels have reduced widths that are comparable with the Wigner limit. The presence of a broad singlet $1^{-}$ level at 9.8 MeV is indicated with somewhat less confidence.