Spectroscopic study of Ca-47 from the beta(-) decay of K-47

The beta(-) decay of K-47 to Ca-47 is an appropriate mechanism for benchmarking interactions spanning the sd and pf shells, but current knowledge of the beta(-) -decay scheme is limited. We have performed a high-resolution, high-efficiency study of the beta(-) decay of K-47 with the GRIFFIN spectrometer at TRIUMF-ISAC. The study revealed 48 new transitions, a more precise value for the K-47 half-life [17.38(3) s], and new spin and parity assignments for 8 excited states. Levels placed for the first time here raise the highest state observed in beta(- )decay to within 568(3) keV of the Q value and confirm the previously measured large beta(-) decay branching ratios to the low-lying states. Previously unobserved beta(-) feeding to 3/2(+) states between 4.5 and 6.1 MeV excitation energy was identified with a total beta(-) feeding intensity of 1.29(2)%. The sum of the B(GT) values for these states indicates that the 1s(1/2) proton hole strength near this excitation energy is comparable to the previously known 1s(1/2) proton and neutron hole strengths near 2.6 MeV.