NonradiativeE2Transitions inμMesonic Atoms

An investigation is made of the possibility that a ${\mu }^{-}$ meson, bound in a $3D$ orbit about a very heavy element, could make a nonradiative transition to the $1S$ state accompanied by electric excitation of the nucleus. A rough calculation, based on recent data on the photofission of ${\mathrm{U}}^{238}$, indicates that this process may compete favorably with $3D\to 2P$ x-ray emission.