The double Gamow-Teller strength distribution is evaluated microscopically in a series of light and medium mass nuclei using the shell model approach. The specific 2β decay transition from the ground state to ground state is computed in all the nuclei considered and the model dependence of the result is studied. The importance of the coherence when summing over the intermediate states is studied and is found to be a crucial factor in most of the double Gamow-Teller transitions. The effects of SU(4) symmetry breaking are studied using several models and types of interactions. This breaking is much larger in medium mass nuclei (A = 44) than in the lighter nuclei (A = 8, 12, or 20). The behaviour of double Gamow-Teller ground state to ground state transition amplitudes on the size of the model space is found to be complicated and to be different for different nuclei. The probabilities of studying double Gamow-Teller strength in combined (p, n) and (n, p) experiment, in pion double charge-exchange, and charge-exchange reactions are discussed.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)