Fusing photons into nothing, a new search for invisible ALPs and Dark Matter at Belle II

Abstract

Abstract We consider an axion-like particle coupled to the Standard Model photons and decaying invisibly at Belle II. We propose a new search in the e + e − + invisible channel that we compare against the standard γ + invisible channel. We find that the e + e − + invisible channel has the potential to ameliorate the reach for the whole ALP mass range. This search leverages dedicated kinematic variables which significantly suppress the Standard Model background. We explore the implications of our expected reach for Dark Matter freeze-out through ALP-mediated annihilations.

Keywords

• Axions and ALPs
• Dark Matter at Colliders
• Specific BSM Phenomenology