Direct-decay properties of charge-exchange spin giant resonances

Abstract

An extended continuum-RPA approach is applied to describe direct-decay properties of spin giant resonances in ${}^{208}$Bi and ${}^{90}$Nb. Partial branching ratios for direct proton decay from these resonances are evaluated. The branching ratio for $\gamma$-decay from the spin-dipole resonance to the Gamow-Teller resonance (main peak) is estimated. The saturation-like behaviour of the mean doorway-state spreading width in ${}^{208}$Pb is discussed in connection with the branching ratio for direct proton decay from the spin-monopole resonance and the Gamow-Teller strength distribution.

Comments: 6 pages, 2 figures, Talk given at the International Conference on Giant Resonances (GR2000),June 2000, Osaka, Japan