SPREADING OF THE GAMOW-TELLER RESONANCE IN NB-90 AND BI-208

Spreading properties of the Gamow-Teller resonance in Nb-90 and Bi-208 are Studied within an approach including the 2p2h configuration mixin g and the ground-state correlations beyond the random-phase approximat ion. The M3Y interaction and single-particle wave functions within the standard harmonic oscillator potential are used in numerical calculat ions. The single-particle energies around the Fermi surface are replac ed with the empirical values or those given by a Woods-Saxon potential . Results obtained provide a reasonable account for recent experimenta l findings. The extension of the present approach to hot nuclei is als o provided.