Detailed study of Gamow-Teller transitions: The impact on astro and nuclear-structure physics

The Gamow-Teller (GT) transition is one of the most popular nuclear weak processes of the spin-isospin (στ) type. It is of interest not only in nuclear physics, but also in astrophysics; it plays important roles, for example, in supernova-explosions or nuclear synthesis. Relatively limited information can be obtained directly through the study of weak processes themselves. However, it was found that charge-exchange (CE) reactions at intermediate incoming energies at 0° selectively excite GT transitions, which could extend the energy region of the study. With an improvement of the energy resolution in (3He,t) CE measurements, fine structures of GT excitations, even those of GT giant resonances, can now be studied. Determination of GT transition strengths for pf-shell nuclei with astrophysical interest is discussed. We show that the quantum number “isospin” plays important roles in such studies.