A dipole–quadrupole interaction term in E1 photon transitions

Evidence is presented for a dipole–quadrupole interaction term in the primary E1 transitions of average resonance capture data. This evidence is obtained by testing a proposed generalized Landau Fermi liquid model for spherical and deformed nuclei, which includes the effect of the dipole–quadrupole interaction. The present formulation succeeded in unifying the description of the E1 photon strength functions for spherical and deformed nuclei. The Landau–Migdal interaction constants, as well as the effective nucleon mass, are determined as F0′=1.49±0.08, F1=0.12±0.21, and m∗/m=1.04±0.07. The temperature dependence of the damping width of the giant dipole resonance is investigated within a generalized Fermi liquid model and its predictions are compared with experimental data, as well as microscopic calculations.