Search for Lepton Flavor Violation in $K^+$ Decays

TL;DR

This paper reports a search for lepton flavor violating decays in $K^+$ particles, setting upper limits on their branching ratios, and finds no evidence of such violations in the analyzed data.

Contribution

The study provides the first stringent upper limits on several lepton flavor violating $K^+$ decay modes using data from the E865 experiment.

Findings

No signal observed in any decay mode

Branching ratio limits set at 90% confidence level

Improved constraints on lepton flavor violation in kaon decays

Abstract

A search for lepton flavor violating decays, \kmmp, \keep, \kpem, \kmep and \pizem, was performed using the data collected in E865 at the Brookhaven Alternating Gradient Synchrotron. No signal was found in any of the decay modes. At the 90% confidence level, the branching ratios are less than $3.0\times10^{-9}$, $6.4\times10^{-10}$, $5.2\times10^{-10}$, $5.0\times10^{-10}$ and $3.4\times10^{-9}$ respectively.