Extended random-phase-approximation study of fragmentation of giant quadrupole resonance in $^{16}$O

Abstract

The damping of isoscalar giant quadrupole resonance in 16 O is studied using extended randomphase-approximation approaches derived from the time-dependent density-matrix theory. It is pointed out that the effects of ground-state correlations bring strong fragmentation of quadrupole strength even if the number of two particle-two hole configurations is strongly limited.