High-resolution study ofB11toC11Gamow-Teller strengths as a test case ofab initioshell-model calculations

Abstract

A high energy-resolution $^{11}\mathrm{B}(^{3}\mathrm{He},t)^{11}\mathrm{C}$ experiment was performed at $0\ifmmode^\circ\else\textdegree\fi{}$ and an intermediate incident energy of $140\phantom{\rule{0.3em}{0ex}}\mathrm{MeV}∕\mathrm{nucleon}$ for the study of precise Gamow-Teller (GT) transition strengths. Two doublet states at $\ensuremath{\approx}4.5$ and $\ensuremath{\approx}8.4\phantom{\rule{0.3em}{0ex}}\mathrm{MeV}$ were clearly resolved with a resolution of $45\phantom{\rule{0.3em}{0ex}}\mathrm{keV}$. The strengths are compared with a calculation using an ab initio no-core shell model, which became available for the $A=11$ system recently. It was found that a calculation including a three-nucleon interaction better reproduces the observed GT transition strengths.