Resonances in 28Si+28Si. I

TL;DR

This paper develops a molecular model to explain resonances in 28Si+28Si collisions, identifying stable configurations and normal modes that account for observed resonances and wobbling motion due to asymmetric shapes.

Contribution

It introduces a novel molecular model for medium light heavy-ion resonances, analyzing stable dinuclear configurations and their normal modes, including wobbling motion, in 28Si+28Si collisions.

Findings

Identification of a stable equator-equator touching configuration.

Normal modes as origins of observed resonances.

Wobbling motion due to asymmetric shape influences energy spectra.

Abstract

A molecular model developed for resonances observed in medium light heavy-ion collisions is described. At high spins in 28Si+28Si (oblate-oblate system), a stable dinuclear configuration is found to be equator-equator touching one. The normal modes around the equilibrium are investigated. These modes are expected to be the origin of a large number of resonances observed. Furthermore, due to the axially asymmetric shape of the stable configuration of 28Si+28Si, the system rotates preferentially around the axis with the largest moment of inertia, which gives rise to wobbling motion ($K$-mixing). Energy spectra for the normal modes and for the extended model including the wobbling motion are given.