Giant dipole resonance width as a probe for nuclear deformation at finite excitation

TL;DR

This paper investigates the relationship between giant dipole resonance width and nuclear deformation at finite excitation, showing a universal correlation that enables direct experimental determination of nuclear shape changes across various nuclei.

Contribution

It demonstrates that the GDR width correlates with nuclear deformation in a non-linear way, validated by the thermal shape fluctuation model, across a wide mass range.

Findings

GDR width and deformation correlation is non-linear and mass-dependent.

Empirical deformation values from GDR width match thermal shape fluctuation model.

Universal correlation allows direct measurement of nuclear deformation at finite temperature.

Abstract

The systematic study of the correlation between the experimental giant dipole resonance (GDR) width and the average deformation <\beta> of the nucleus at finite excitation is presented for the mass region A ~ 59 to 208. We show that the width of the GDR (\Gamma) and the quadrupole deformation of the nucleus do not follow a linear relation, as predicted earlier, due to the GDR induced quadrupole moment and the correlation also depends on the mass of the nuclei. The different empirical values of <\beta> extracted from the experimental GDR width match exceptionally well with the thermal shape fluctuation model. As a result, this universal correlation between <\beta> and \Gamma provides a direct experimental probe to determine the nuclear deformation at finite temperature and angular momentum in the entire mass region.