High-resolution study of~(37)Cl → ~(37)Ar Gamow-Teller transitionvia ~(37)Cl(~3He,t)~(37)Ar reaction

摘要

We performed a ~(37)Cl(~3He,t)~(37)Ar experiment at E = 140 MeV/nucleon and 0° with a resolution of 30 keV. The Gamow-Teller (GT) strength distribution was obtained up to the excitation energy (E_x) of 14.2 MeV in ~(37)Ar. Under the assumption of isospin symmetry, the GT strengths in the ~(31)Cl → ~(37)Ar and ~(37)Ca → ~(37)K transitions are analogous. The obtained strength distribution was compared with the mirror ~(37)Ca β decay up to E_x = 8.6 MeV. The overall shapes of the distributions were similar, but the details were not necessary the same. In order to understand those differences, the experimental distribution was compared with the shell model (SM) calculation using the USD interaction. The SM calculation suggests that differences at lower energies can be caused by a large tensor contribution in the charge-exchange reaction. On the other hand, the differences seen at higher energies are due to the breaking of the mirror symmetry. The neutrino cross section for the ~8B solar neutrino source was calculated using the obtained data.