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199047 citationsJournal Article

Authors

A. M. Lee · Brookhaven National Laboratory

C. Alliegro · University of Washington

C. Campagnari · Brookhaven National Laboratory

V. Chaloupka · Paul Scherrer Institute

P. S. Cooper · Paul Scherrer Institute

J. Egger · Paul Scherrer Institute

H. A. Gordon ·

Abstract

A search for the lepton-flavor number-violating decay ${K}^{+}$\ensuremath{\rightarrow}${\ensuremath{\pi}}^{+}$${\ensuremath{\mu}}^{+}$${e}^{\mathrm{\ensuremath{-}}}$ has been conducted at the Brookhaven Alternating Gradient Synchrotron. No candidates have been found which would be consistent with this decay mode. An upper limit on the branching ratio is placed at 2.6\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}10}$, which can be combined with our previous result to yield an upper limit of 2.1\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}10}$ at the 90% confidence level. A limit on the branching ratio for ${\ensuremath{\pi}}^{0}$\ensuremath{\rightarrow}${\ensuremath{\mu}}^{+}$${e}^{\mathrm{\ensuremath{-}}}$ of 1.6\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}8}$ (90% C.L.) is also established.

Topics & Keywords

Particle physics theoretical and experimental studies Dark Matter and Cosmic Phenomena Neutrino Physics Research

Publication Details

Published in: Physical Review Letters

Volume 64, Issue 2, pp. 165-168

DOI: 10.1103/physrevlett.64.165

Field-Weighted Citation Impact: 7.89

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