γ rays from muon capture inAl27and natural Si

Abstract

Muon capture $\ensuremath{\gamma}$ rays have been observed for the first time in $^{27}\mathrm{Al}$, and a significant improvement has been made in the identification of \ensuremath{\gamma}-rays from muon capture in natural Si. The (${\ensuremath{\mu}}^{\ensuremath{-}},\ensuremath{\nu}\ensuremath{\gamma}$) reaction was clearly observed in both nuclei and, for $^{28}\mathrm{Si}$, compares well with calculations. The (${\ensuremath{\mu}}^{\ensuremath{-}},\ensuremath{\nu}n\ensuremath{\gamma}$) reaction was also observed strongly in both nuclei, and the levels which are excited correlate fairly well with the ($\ensuremath{\gamma},p$) reaction, but not as well with the spectroscopic factors from the ($d$, $^{3}\mathrm{He}$) reaction. Some (${\ensuremath{\mu}}^{\ensuremath{-}},\ensuremath{\nu}2n\ensuremath{\gamma}$), (${\ensuremath{\mu}}^{\ensuremath{-}},\ensuremath{\nu}3n\ensuremath{\gamma}$), (${\ensuremath{\mu}}^{\ensuremath{-}},\ensuremath{\nu}p\ensuremath{\gamma}$), (${\ensuremath{\mu}}^{\ensuremath{-}},\ensuremath{\nu}\mathit{pn}\ensuremath{\gamma}$), and other reactions have been observed at a lower yield. The Lyman series of the muonic x ray cascades have also been studied.