Relation between Mn, Mp and hadronic excitation strengths when there is strong absorption: The AZr(α, α′) reactions

Abstract

Abstract We study the relationship between the r 1 radial moments M n , M p of neutron and proton transition densities and the corresponding interaction strengths at the large radii sampled by a hadronic probe when there is strong absorption. We use a folding model and a gaussian alpha-nucleon interaction to generate the transition potentials for A Zr( α , α ′) reactions at 35.4 MeV. Simple transition density models were considered, as well as a valence plus core polarization model, and applied to some 2 1 + and 3 1 − excitations for A = 90, 92 and 96. We show that the M n / M p ratios extracted can be very sensitive to the shapes assumed for the transition densities. The ratios deduced from the A Zr( α , α ′) data are smaller than those deduced recently using an implicit procedure, but still considerably larger than N / Z for A > 90. Explicit consideration of a few valence nucleons can produce significant variations.