Fragmentation of Gamow-Teller strength observed in 117,120Sn(3He,t)117,120Sb charge-exchange reactions.

The ([sup 3]He,[ital t]) charge-exchange reaction has been studied at [ital E]([sup 3]He)=200 MeV and angles near 0[degree] on targets of [sup 117]Sn and [sup 120]Sn. Fragmentation of the giant Gamow-Teller resonance into separate components of the particle-hole type has been observed in good agreement with theoretical predictions. These components are connected with what is usually referred to in the literature as direct-, core-polarization-, and back-spin-flip Gamow-Teller strength. The observed cross sections near [theta]=0[degree] suggest contributions from the isovector spin-flip interaction as well as the isovector tensor interaction. A theoretically predicted configuration splitting of the main Gamow-Teller component into two components involving the 1[ital h][sub 11/2] neutron orbital could not uniquely be identified. The data are compatible, though, with such a splitting since the observed widths of the main Gamow-Teller components in [sup 117]Sb and [sup 120]Sb exceed the predicted splittings.