alpha+28Si and 16O+16O molecular states, and their isoscalar monopole strengths

Abstract

The properties of the α+ 28 Si and 16 O+ 16 O molecular states which are embedded in the excited states of 32 S and can have an impact on the stellar reactions, are investigated using the antisymmetrized molecular dynamics. From the analysis of the cluster spectroscopic factors, the candidates of α+ 28 Si and 16 O+ 16 O molecular states are identified close to and above the cluster threshold energies. The calculated properties of the α+ 28 Si molecular states are consistent with those reported by the α+ 28 Si resonant scattering experiments. On the other hand, the 16 O+ 16 O molecular state, which is predicted to be identical to the superdeformation of 32 S, is inconsistent with the assignment proposed by an α inelastic scattering experiment. Our calculation suggests that the monopole transition from the ground state to the 16 O+ 16 O molecular state is rather weak and is not strongly excited by the α inelastic scattering.