Hyperfine effects in parity-violating muonic-atom decays

Abstract

The effect of hyperfine interactions on the parity-violating correlations in the decay $2S_{\frac{1}{2}}\to 1S_{\frac{1}{2}}+1\mathrm{}\gamma$ in muonic atoms is considered. It is shown that hyperfine effects make the photon momentum correlations with the initial or the final muon polarization unequal to each other, and unequal to the photon circular polarization. Also, there is an additional parity-violating term in the muon-proton Hamiltonian, proportional to the nuclear spin, which contributes differently to the three spin correlations. Therefore, if measurements of two of these correlations are possible in light atoms, both parity-violating coupling constants can be determined.