A New Flavor of Searches for Axion-Like Particles

TL;DR

This paper introduces novel search strategies for axion-like particles via flavor-changing neutral current processes, leveraging their coupling to W bosons to enhance detection prospects in meson decays.

Contribution

It proposes new experimental searches for ALPs through FCNC processes, focusing on their coupling to W bosons, which has been less explored in previous studies.

Findings

Potential to significantly improve sensitivity to ALP couplings

Constraints and discovery prospects for invisible ALPs

Enhanced detection methods in meson decay channels

Abstract

We propose new searches for axion-like particles (ALPs) produced in flavor-changing neutral current (FCNC) processes. This proposal exploits the often-overlooked coupling of ALPs to W bosons, leading to FCNC production of ALPs even in the absence of a direct coupling to fermions. Our proposed searches for resonant ALP production in decays such as $B\rightarrow K^{(*)}a,\,a\rightarrow \gamma\gamma$ and $K\rightarrow \pi a, \,a\rightarrow \gamma\gamma$ could greatly improve upon the current sensitivity to ALP couplings to Standard Model particles. We also determine analogous constraints and discovery prospects for invisibly decaying ALPs.