Isovector giant dipole resonance in hot rotating light nuclei in the calcium region.

Abstract

The isovector giant dipole resonances in hot rotating light nuclei in the calcium region are studied using a rotating anisotropic harmonic oscillator potential and a separable dipole-dipole residual interaction. The influence of temperature on the isovector giant dipole resonance is assumed to occur through the change of deformation of the average field only. Calculations are performed for the three nuclei $^{40}$,42Ca and $^{46}\mathrm{Ti}$ which have spherical, oblate, and prolate ground states, respectively, to see how their shape transitions at higher excited states affect the isovector giant resonance frequencies built on them. It is seen that, while the width fluctuations present at T=0 vanish at T=0.5 MeV in $^{40}$,42Ca, they persist up to T=1.5 MeV in the case of $^{46}\mathrm{Ti}$. This behavior brings out the role of temperature on shell effects which in turn affects the isovector giant dipole resonance widths.