Radiative lepton flavor violating B, D, and K decays

TL;DR

This paper discusses how radiative lepton flavor violating meson decays can serve as powerful probes for new physics, providing constraints on effective operators and motivating experimental searches.

Contribution

It establishes a generic framework for analyzing RLFV meson decays and highlights their unique sensitivity to operators not accessible via two-body decays.

Findings

RLFV decays can constrain lepton flavor-changing neutral current operators.

These decays access operators not constrained by two-body processes.

The paper motivates experimental searches for RLFV channels.

Abstract

We argue that radiative lepton flavor violating (RLFV) decays $P \to \gamma \ell_1 \overline{\ell}_2$ of $P =B^0_q$, $\bar{D}^0$, and $K^0$ meson states are robust probes of new physics models. In particular, they could be used to put constraints on the Wilson coefficients of effective operators describing lepton flavor-changing neutral current interactions at low energy scales. We set up a generic framework for describing these transitions and review new physics constraints from $P \to \ell_1 \bar \ell_2$ decays. There is discussion of how RLFV transitions provide access to the operators that cannot be constrained in two-body decays and we in turn motivate further experimental searches via these channels.