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

TL;DR

This study investigates alpha+28Si and 16O+16O molecular states within 32S using antisymmetrized molecular dynamics, revealing their properties, potential impact on stellar reactions, and differences from experimental assignments.

Contribution

It provides new theoretical insights into the properties and identification of molecular states in 32S, challenging previous experimental interpretations.

Findings

Alpha+28Si molecular states align with resonant scattering data.

16O+16O molecular state matches superdeformation but contradicts previous experiments.

Monopole transition to 16O+16O state is weak and not strongly excited by alpha scattering.

Abstract

The properties of the alpha+28Si and 16O+16O molecular states which are embedded in the excited states of 32S 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 alpha+28Si and 16O+16O molecular states are identified close to and above the cluster threshold energies. The calculated properties of the alpha+28Si molecular states are consistent with those reported by the alpha+28Siresonant scattering experiments. On the other hand, the 16O+16O molecular state, which is predicted to be identical to the superdeformation of 32S, is inconsistent with the assignment proposed by an alpha inelastic scattering experiment. Our calculation suggests that the monopole transition from the ground state to the 16O+16O molecular state is rather weak and is not strongly excited by the alpha inelastic scattering.