Radiative Pion Capture from the1sLevel inLi6

Abstract

Partial rates for radiative capture from the $1s$ atomic level in ${}_{}{}^6{}_{}{}^{}\mathrm{Li}$ to the lowest two ${}_{}{}^6{}_{}{}^{}\mathrm{He}$ states have been determined by measuring, with the necessary energy resolution, x rays and high-energy photons in coincidence. A comparison of our results and other related experimental results with different theoretical approaches shows that phenomenological wave functions consistently describe photopion processes as well as electromagnetic and weak transitions between low-lying ${}_{}{}^6{}_{}{}^{}\mathrm{Li}$ and ${}_{}{}^6{}_{}{}^{}\mathrm{He}$ states.