Possible enhancement of theE1decay rates of double giant dipole states

Abstract

The E1 transitional rates between the double giant dipole resonance (DGDR) states and giant dipole resonance (GDR) ones are studied using the wave functions, which include one-, two-, and many-phonon components. It is shown that there is a possibility for the enhancement of the E1 transition rates from the DGDR states to the GDR ones as compared to the harmonic limit. This enhancement arises from the matrix elements for the E1 transitions between many-phonon terms of the wave functions, which differ by one E1 phonon. {copyright} {ital 1997} {ital The American Physical Society}