Invisible decays of axion-like particles: constraints and prospects

Axion-like particles (ALPs) can provide a portal to new states of dark sector. We study the phenomenology this when ALP mainly decays invisibly, while its interaction with standard model sector proceeds essentially via coupling electrons and/or photons. re-analyse existing limits from various collider and beam dump experiments, including in particular production electron/positron interactions, addition usual through ALP-photon coupling. further discuss interplay between these intriguing possibility explaining simultaneously muon electron magnetic moment anomalies. Finally, we illustrate prospects searches at LNF positron fixed-target experiment PADME, future reach an upgraded experimental setup.