Energy shift in the

Abstract

The energy shift due to the presence of the extended ({ital dt}{mu}){sub 11} pseudonucleus (in its first excited state with one unit of angular momentum) in the quasihydrogenlike molecule (({ital dt}{mu}){sub 11}{minus}{ital d}){ital ee} is estimated using first-order perturbation theory. The quadrupole parts of the electron-({ital dt}{mu}){sub 11} and deuteron-({ital dt}{mu}){sub 11} interactions are found to give energy shifts of several meV. The result suggests that the normal practice of calculating the shift in (({ital dt}{mu}){sub 11}{minus}{ital d}){ital ee} by scaling the shift calculated for ({ital dt}{mu}){sub 11}{ital e} may be in error. Calculations of the formation rate of (({ital dt}{mu}){sub 11}{minus}{ital d}){ital ee}, which plays an important role in muon-catalyzed fusion, require an accuracy of about 1 meV in the binding energy, and the present result indicates that a shift in this binding energy of several meV, due to the finite ({ital dt}{mu}){sub 11} size, cannot yet be excluded.