Systematics of theστ−strength in nuclei

The structure of the $\sigma {\tau }_{-}$ strength function is studied with a zero range interaction. The systematics of the giant Gamow-Teller state requires an interaction strength for $V_{\sigma \tau }$ of about 200-240 MeV ${\mathrm{fm}}^3$. While most of the strength goes to a state at high excitation, we find that ∼20-30% of the strength remains at low excitation energy. The $L=1\mathrm{}$ states show considerable $J$ splitting, with a major peak at ≅20 MeV excitation. This peak contains components of $J=0,1, \mathrm{and} 2$. Comparison with the experimental $L=1\mathrm{}$ energy shows that the momentum dependence of the $\sigma \tau$ interaction is small.