Muon transfer from mesic hydrogen to helium

Binding energies and formation rates of p mu He molecules, determining the rate of muon transfer from unexcited mesic hydrogen to helium, are calculated. The screening of nuclear charge by the atomic electrons is taken into account, as well as the electron form factor of the remainder, in the field of which the outgoing electron moves. The results obtained in a one-level approximation as well as in a 'simple-approach approximation' are compared with the experimental data.