Low-energy supernova constraints on lepton flavor violating axions

A bstract The extreme conditions within the supernova core, a high-temperature and high-density environment, create an ideal laboratory for the search for new physics beyond the Standard Model. Of particular interest are low-energy supernovae, characterized by their low explosion energies, which place strong constraints on the new-physics energy transfer from the core to the mantle. We compute low-energy supernova constraints on lepton-flavor-violating axions and axion-like particles that couple to both electrons and muons. For axion mass above the muon mass, the electron-muon coalescence and the axion decay are dominant production and reabsorption processes, respectively. We find that the low-energy supernovae provide the most stringent constraints on the axions in the mass range of ∼ (110 , 550) MeV, probing the coupling constant down to $${g}_{ae\mu }\simeq \mathcal{O}({10}^{-11})$$ .