Effect of meson exchange current on deuteron muon capture

Abstract The effect of meson exchange current was investigated on the energy spectrum of the emitted neutron and the asymmetric angular distribution of the neutrino in muon capture in the deuteron, μ − + d → n + n + v . We adopt the one-pion and one-rho-meson exchange model and the Siegert theorem for electric multipole amplitude in order to satisfy phenomenologically the vector-current conservation relation. We found a large effect of the meson exchange current on the neutron energy spectrum, particularly at high energies, in the muon capture from doublet and quartet hyperfine states. The asymmetry coefficient of the neutrino is also affected significantly by the exchange current in the muon capture from the doublet hyperfine state, but not from the quartet state.