A study of 36S by high-resolution inelastic proton and alpha scattering

In an inelastic hadron scattering study of 36S both a high resolution (p, p') experiment at Ep=28.0 MeV and an (α, α') experiment at Eα=31.6 MeV were performed. A highly enriched target was used. Angular distributions for levels up to 6.55 MeV have been obtained. Five previously unknown levels have been observed. A macroscopic CC analysis with a phenomenological potential was performed for the inelastic levels, yielding Jπ assignments for several states. The different angular distributions for the 21+ and 22+ states could be accounted for by assuming a transition potential that has a contribution in the nuclear interior. Apart from the 3- state at Ex=4.193 MeV a 4- state and 5- state were identified, for which phenomenological octupole band calculations have been performed. Explicit folding-model calculations, essential for a consistent description of 0+ and 1- states, have been performed for several levels, using the JLM nucleon-nucleon interaction both for (p, p') and for (α, α'). A rather good description of the differential cross sections of several levels, including the 0+ and 1- states, is obtained. A direct comparison between the results from a (p, p') and an (α, α') folding-model analysis is made, resulting in isoscalar B(Eλ) values. Microscopic calculations have been performed for the (p, p') results. The transition densities are obtained from shell-model (SM) and extended-RPA (E-RPA) calculations. No effective charges were introduced. The E-RPA calculations gave a fair description of the differential cross sections of several levels. In the SM calculations the neutron part of the transition density is severely underestimated. (orig.)