Speaker
Description
Experimental studies of charge-exchange nuclear and leptonic reactions are useful for evaluating nuclear matrix elements (NMEs) for double beta decays (DBDs). The sin-dipole (SD) NME is one of the major components of the DBD NME. The experimental SD giant resonance energy and the SD strength are shown to be closely related with pnQRPA NME. The NME is obtained by using the particle hole interaction derived from the experimental SD giant resonance energy and the quenching coefficient (0.65) for the axial-vector coupling derived from the experimental GT and SD strengths. The NME is given as a smooth function of the mass number A as M ~ 5.2-0.023 A for medium heavy nuclei wit A = 76 - 136, which are of current interest. The quenching is partly due to the delta isobar effect, which is not explicitly included in the pnQRPA. Impact of the NME on future DBD experiment is discussed.
