More on R-parity and lepton-family number violating couplings from muon(ium) conversion, and τand $\ddot{I}{€}^0$ decays

Abstract

We present a new class of constraints to the lepton-family number and R-parity violating couplings from muonium conversion, $\hat{I}{¼}^{-}+{}_{22}^{48}Ti\to e^{-}+{}_{22}^{48}Ti$, a class of tau decays, $\ddot{I}„\to l+$ (light meson) with $l=\hat{I}¼ore$, and $J/\ddot{I}ˆ$ and $\ddot{I}{€}^0$ decays into a lepton pair. We find that $\hat{I}{¼}^{-}+{}_{22}^{48}Ti\to e^{-}+{}_{22}^{48}Ti$ provides one of the strongest constraints along with $\hat{I}”m_K,\hat{I}”m_B$, $\hat{I}¼\to e{\hat{I}}^3$ and the neutrinoless double ${\hat{I}}^2$ decay. Search for these lepton-family number violating (LFNV) decays forbidden in the standard model is clearly warranted in various low-energy experiments such as Tau-Charm Factories and PSI, etc.

13 pages, no figures, RevTeX