γ decay of giant resonances to low-lying states

With growing studies on giant resonances, the deep insight about their damping mechanisms draws more and more attentions. Here we provide an alternative way to study the detailed structures of giant resonances apart from the wavelet analysis of the high-resolution strength distribution, including isospin properties and wavefunctions, the latter of which indicates the main damping mechanism of giant resonances. We utilize a fully self-consistent random phase approximation (RPA) + particle vibration coupling (PVC) model to calculate the gamma decay width based on Skyrme density functional. We find that the complex configuration, i.e., one-particle one-hole coupled with phonon, has much larger component in the wave-function of GQR than that of GDR, which indicates the main damping mechanisms in these two modes are different.