Low-Energy Supernova Constraints on Lepton Flavor Violating Axions

TL;DR

This paper investigates how low-energy supernovae can constrain lepton-flavor-violating axions, revealing that such supernovae provide the strongest bounds for axion masses between 110 and 550 MeV.

Contribution

It calculates new constraints on lepton-flavor-violating axions using low-energy supernova models, especially in the 110-550 MeV mass range, improving previous bounds.

Findings

Low-energy supernovae set the most stringent limits on axion-electron-muon couplings.

Constraints reach coupling constants as low as 10^{-11}.

Axion mass range of 110-550 MeV is particularly constrained.

Abstract

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 $\sim (110,550)$ MeV, probing the coupling constant down to $g_{ae\mu} \simeq {\cal O}(10^{-11})$.