Isovector response and energy-weighted sums in hot nuclei

Abstract

We investigate the collective response function and the energy-weighted sums (EWS) $m_k$ for isovector mode in hot nuclei. The approach is based on the collisional kinetic theory and takes into consideration the temperature and the relaxation effects. We have evaluated the temperature dependence of the adiabatic, $E_1=\sqrt{m_1/m_{-1}}$, and scaling, $E_3=\sqrt{m_3/m_1}$, energy centroids of the isovector giant dipole resonances (IVGDR). The centroid energy $E_3$ is significantly influenced by the Fermi surface distortion effects and, in contrast to the isoscalar mode, shows much weaker variation with temperature. Taking into account a connection between the isovector sound mode and the corresponding surface vibrations we have established the $A$-dependence of the IVGDR centroid energy which is in a good agreement with experimental data. We have shown that the enhancement factor for the "model independent" sum $m_1$ is only slightly sensitive to the temperature change.

arXiv comment28 pages, 8 figures, revised version

References in corpus (8)

• Microscopic Calculation of in-Medium Nucleon-Nucleon Cross Ssections
• Microscopic Calculation of in-Medium Proton-Proton Cross Sections
• Compilation of Giant Electric Dipole Resonances Built on Excited States
• Isovector response function of hot nuclear matter with Skyrme interactions
• Response Function of Hot Nuclear Matter
• Isovector Vibrations in Nuclear Matter at Finite Temperature
• Collisional Damping of Nuclear Collective Vibrations in a Non-Markovian Transport Approach
• Sound modes in hot nuclear matter