Spin-isospin resonances in nuclei

Spin-isospin excitations in nuclei have been investigated via the (He-3,t) reaction at 450 MeV. The volume integrals of the effective interactions J(sigma tau) and J(tau) for the (He-3,t) reaction at 450 MeV have been empirically determined to be 172+/-17 MeV-fm(3) and 53+/-5 MeV-fm(3), respectively. These values are consistent with those obtained for the (p,n) reaction at the same bombarding energy per nucleon. The Gamow-Teller strength can be deduced with the same reliability as the (p,n) reaction at the bombarding energy above 100 MeV. The neutrino absorption cross sections by Ga-71 is obtained on basis of the present (He-3,t) measurement. The new SNU value obtained for Ga-71 is 130.3+/-1.6(stat.)+/-16.8(syst.). The spin-isospin responses for the Sn isotopes, Cd-116 and Mo-100 are presented and are discussed in relation with double beta-decay. A measurement of decay protons from the spin-isospin resonances in N-13 is presented. A new possibility of studying the spin-isospin responses on the beta(+) side via the (t,He-3) reaction using a dispersion matching technique is discussed.