Supernova bound on Axion-Like Particles coupled with electrons

TL;DR

This paper derives constraints on axion-like particles with electron couplings from supernova cooling data, extending the bounds to higher masses and lower couplings using detailed supernova simulations.

Contribution

It provides the first comprehensive evaluation of supernova bounds on ALPs with masses up to 200 MeV, incorporating thermal effects and advanced simulations.

Findings

Excludes new parameter space for ALPs with masses 1-200 MeV.

Sets bounds on ALP-electron coupling down to 2.5×10⁻¹⁰.

Improves previous supernova constraints with detailed modeling.

Abstract

Axion-Like Particles (ALPs) coupled with electrons would be produced in a Supernova (SN) via electron-proton bremsstrahlung and electron-positron fusion. We evaluate the ALP emissivity from these processes by taking into account the ALP mass and thermal effects on electrons in the strongly degenerate and relativistic SN plasma. Using a state-of-the-art SN simulation, we evaluate the SN 1987A cooling bound on ALPs for masses in the range $1-200$ MeV, which excludes currently unprobed regions down to $g_{ae}\sim 2.5\times 10^{-10}$ at $m_a\sim 120$ MeV.