New bounds on lepton flavor violating decays of vector mesons and the Z0 boson

TL;DR

This paper estimates upper bounds on lepton flavor violating decays of vector mesons and the Z0 boson, showing these processes are highly suppressed and unlikely to be observed experimentally due to existing constraints.

Contribution

It provides model-independent upper bounds on LFV decays of vector mesons and Z0 boson, improving upon previous limits and analyzing their connection to nuclear mu-e conversion.

Findings

LFV decay rates are strongly suppressed by existing experimental limits.

Upper bounds on some decay rates are more stringent than previous estimates.

Experimental observation of these LFV decays is currently unrealistic.

Abstract

We give an estimate for the upper bounds on rates of lepton flavor violating (LFV) decays M to mu(pm) + e(mp) of vector mesons M = rho0, omega, phi, J/psi, Upsilon and the Z0 boson in a model independent way, analyzing the corresponding lowest dimension effective operators. These operators also contribute to nuclear mu-e-conversion. Based on this observation and using the existing experimental limits on this LFV nuclear process, we show that the studied two-body LFV decays of vector bosons are strongly suppressed independent on the explicit realization of new physics. The upper limits on the rates of some of these decays are significantly more stringent than similar limits known in the literature. In view of these results experimental observation of the two-body LFV decays of vector bosons looks presently unrealistic.