Giant dipole resonance width as a probe for nuclear deformation at finite excitation
The first systematic study of the correlation between the experimental giant dipole resonance (GDR) width and the average deformation � β� of the nucleus at finite excitation is presented for the mass region A ∼ 59 to 208. We show that the width of the GDR (� ) and the quadrupole deformation of the nucleus do not follow a linear relation, as predicted earlier, owing to the GDR-induced quadrupole moment, and the correlation also depends on the mass of the nuclei. The different empirical values of � β� extracted from the experimental GDR width match exceptionally well with the thermal shape fluctuation model. As a result, this universal correlation between