6533b7d3fe1ef96bd125fec8

RESEARCH PRODUCT

Improved search for two body muon decay μ+→e+XH

subject

description

Charged lepton flavor violating muon decay ${\ensuremath{\mu}}^{+}\ensuremath{\rightarrow}{e}^{+}{X}_{H}$, where ${X}_{H}$ is a massive neutral boson, was sought by searching for extra peaks in the muon decay ${\ensuremath{\mu}}^{+}\ensuremath{\rightarrow}{e}^{+}\ensuremath{\nu}\overline{\ensuremath{\nu}}$ energy spectrum in the ${m}_{{X}_{H}}$ mass region $47.8--95.1\text{ }\text{ }\mathrm{MeV}/{c}^{2}$. No signal was found and 90% confidence level upper limits were set on the branching ratio $\mathrm{\ensuremath{\Gamma}}({\ensuremath{\mu}}^{+}\ensuremath{\rightarrow}{e}^{+}{X}_{H})/\mathrm{\ensuremath{\Gamma}}({\ensuremath{\mu}}^{+}\ensuremath{\rightarrow}{e}^{+}\ensuremath{\nu}\overline{\ensuremath{\nu}})$ at the level of ${10}^{\ensuremath{-}5}$ for this region.