Speaker
Description
Nuclear matrix elements (NME) for neutrinoless double beta decays (DBDs) are required for neutrino studies beyond the standard model, and experimental information on the NMEs are crucial for phenomenological model evaluations for the NMEs. Spin dipole (SD) components are one of major ones of the NME. The SD giant resonance energy and the SD strength in the intermediate nucleus have been studied by using charge exchange reactions, and are shown for the first time to be closely related to the pnQRPA model NMEs. On the basis of these experiments, the NME is approximately expressed as M~5.2-0.023 A with A being the mass number for DBD nuclei with A=76-136. The present work is based on recent works of refs. 1,2,3.
1. H. Ejiri, L. Jokiniemi, J. Suhonen, Phys. Rev. C. Letters, 105, L022501 2022.
2. H. Ejiri, Universe 6, 225 2020.
3. H. Ejiri, Frontiers, 9, 650421 2021.
