Improved search for two body muon decay ${\mu}^+{\rightarrow}e^+X_H$

Research paper by A. Aguilar-Arevalo, M. Aoki, M. Blecher, D. I. Britton, D. vom Bruch, D. A. Bryman, S. Chen, J. Comfort, S. Cuen-Rochin, L. Doria, P. Gumplinger, A. Hussein, Y. Igarashi, S. Ito, S. Kettell, et al.

Indexed on: 24 Feb '20Published on: 21 Feb '20Published in: arXiv - High Energy Physics - Experiment


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