Speaker
Description
Experimental studies of nuclear matrix elements for double beta decays are crucial since theoretically evaluated NMEs are very sensitive to the nuclear models and the nuclear parameters used for the calculations. Single and double charge exchange reactions have been used to study experimentally the GT NMEs associated with DBD NMEs. We show in the present work that M1 and E1 gamma transitions from isobaric analogue states excited by charge exchange reactions are used to study axial-vector and vector nuclear matrix elements associated with double beta decays. The effective axial-vector and vector weak couplings are derived experimentally by comparing the observed M1 and EI gamma nuclear matrix elements with the QRPA calculations. Then, these experimental results on the electro-magmetic nuclear matrix elements are well used to help theoretical calculations for the nuclear matrix elements for double beta decays. The gamma transitions are measured in coincidence with the chage exchange reactions. The gamma transition rates are evaluated to show the feasibility of the gamma experiments. It is recently discussed in H. Ejiri, Phys. Rev. C. Letters 108 Lo11302 (2023).
