  Heavy charged particles after nuclear muon capture are an important nuclear
physics background to the muon-to-electron conversion experiments Mu2e and
COMET, which will search for charged lepton flavor violation at an
unprecedented level of sensitivity. The AlCap experiment measured the yield and
energy spectra of protons, deuterons, tritons, and alpha particles emitted
after the nuclear capture of muons stopped in Al, Si, and Ti in the low energy
range relevant for the muon-to-electron conversion experiments. Individual
charged particle types were identified in layered silicon detector packages and
their initial energy distributions were unfolded from the observed energy
spectra. Detailed information on yields and energy spectra for all observed
nuclei are presented in the paper.
