The seminar was dedicated to the research of the ordinary muon capture (OMC) on different isotopically enriched targets, daughter products for nuclear double beta decay. These experiments provide new information for calculations of nuclear matrix elements (NMEs) of double beta decay (DBD). The refinement of the NME calculation of DBD is an important point for interpretation of experimental data in searching for the neutrinoless DBD, a key process for determining fundamental neutrino properties.
To probe the predicted DBD NME models, experimental data about the excited state structure of compound nuclei and strength functions of transitions to these states are needed. And along with the charge-exchange reactions, the OMC makes it possible. The experimental methods, determination of total and partial probability of the OMC, as well as the current research status were reviewed. The results obtained using negative muon beams of the meson factory at PSI (the Paul Scherrer Institute, Villigen, Switzerland) were presented, the good agreement of experimental data with theoretical computations was shown. The prospects of further OMC studies were discussed.