Search for Lepton Flavor Violation Process e^+e^- \to e\mu in the Energy Region \sqrt{s}=984 -- 1060 MeV and \phi\to e\mu Decay

TL;DR

This paper reports a search for lepton flavor violation in electron-positron collisions, setting upper limits on the process e^+e^- o e\mu and the decay \phi o e\mu, within a specific energy range.

Contribution

The study provides the first model-independent upper limits on the e^+e^- o e\mu cross section and \\phi o e\\mu branching fraction in the specified energy region.

Findings

Upper limit on e^+e^- o e\\mu cross section: < 11 pb

Upper limit on \\phi o e\\mu branching fraction: < 2 x 10^{-6}

Results constrain models predicting lepton flavor violation

Abstract

The search for lepton-flavor-violation process e^+e^-\to e\mu in the energy region \sqrt{s}=984 - 1060 MeV with SND detector at VEPP-2M e^+e^- collider is reported. The model independent 90% CL upper limits on the e^+e^-\to e\mu cross section, \sigma_{e\mu} < 11 pb, as well as on the corresponding \phi\to e\mu branching fraction, B(\phi\to e\mu) < 2 \times 10^{-6}, for the final particles polar angles 55^\circ<\theta<125^\circ, were obtained.