Isobaric analog states of the tin and tellurium isotopes studied with the (3He,t) reaction at thetasub(L)=00

The Sn(3He,t)Sb and Te(3He,t)I reactions to the g.s isobaric analog states (IAS) of 112114116117118119120122124Sn and 124125126128130Te have been studied at theta=00 and E(3He)=45.9 MeV. The Coulomb displacement energies decrease more slowly than Asup(-1/3) indicating that the rms radius of the nuclear matter distribution increases more slowly than Asup(1/3). The total widths of the IAS are 10 to 60 keV and exhibit a pronounced odd-A even-A variation correlated with the excitation and decay energies of the IAS. Estimates of the decay and spreading widths have been obtained, with the latter yielding an isospin-mixing matrix element of about 1 keV. The (3He,t) cross sections at 00 appear to be directly related to (p,n) total cross sections for the 0+ IAS. The cross sections for the Sn-Sb and Te-I isotopes, in contrast to accepted expressions, depend in a complicated manner on the neutron excess. A microscopic analysis gives an effective interaction (μ=1fm-1) of Vsub(t.t)=11+-4 MeV. This is smaller than values obtained from analyses of (3He,t) reactions on nuclei with A< approximately 90, if one assumes a simple direct charge-exchange reaction. (Auth.)