학술논문
Spectroscopic study of $^{47}$Ca from the $\beta^-$ decay of $^{47}$K
Document Type
Working Paper
Author
Smith, J. K.; Garnsworthy, A. B.; Pore, J. L.; Andreoiu, C.; MacLean, A. D.; Chester, A.; Beadle, Z.; Ball, G. C.; Bender, P. C.; Bildstein, V.; Braid, R.; Varela, A. Diaz; Dunlop, R.; Evitts, L. J.; Garrett, P. E.; Hackman, G.; Ilyushkin, S. V.; Jigmeddorj, B.; Kuhn, K.; Laffoley, A. T.; Leach, K. G.; Miller, D.; Mills, W. J.; Moore, W.; Moukaddam, M.; Olaizola, B.; Peters, E. E.; Radich, A. J.; Rand, E. T.; Sarazin, F.; Svensson, C. E.; Williams, S. J.; Yates, S. W.
Source
Subject
Language
Abstract
The $\beta^-$ decay of $^{47}$K to $^{47}$Ca 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 $^{47}$K with the GRIFFIN spectrometer at TRIUMF-ISAC. The study revealed 48 new transitions, a more precise value for the $^{47}$K half-life (17.38(3)~s), and new spin and parity assignments for eight 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.