  Some low-energy three-body muon- and electron-transfer processes are
considered within the Faddeev-Hahn formulation using two-, six-, and ten-state
close-coupling approximation. We test our approach in bound-state problems for
systems H$_2^+$ and ($\mu^-$dd)$^+$ within six- and ten-state schemes, where
$d$ is a deuteron and $\mu$ a muon. We present results in the six-state model
for muonium formation from hydrogen. We also present results for muon-transfer
rates from muonic hydrogen isotopes to bare nuclei S$^{16}$ and Ar$^{18}$ in
reasonable agreement with experiment. For these heavier targets a polarization
potential is included and Coulomb potentials are treated exactly without
approximation or cut off.
