Revisiting Supernova 1987A Limits on Axion-Like-Particles

TL;DR

This paper revisits supernova 1987A constraints on axion-like particles, updating bounds on their couplings based on recent models and analyzing different emission processes, with implications for future experiments.

Contribution

It provides new bounds on ALP couplings from supernova data, considering independent photon and nucleon interactions, and clarifies differences from previous limits.

Findings

Bounds on two-photon coupling differ by an order of magnitude from previous estimates.

Volume emission analysis alleviates trapping regime constraints for ALPs with mass > 10 MeV.

Updated limits inform future experimental searches for ALPs.

Abstract

Using recent supernova models, I revisit the Supernova 1987a constraints on scalar/pseudoscalar Axion-Like-Particles (ALPs). On the basis of the neutrino detections, the luminosity of ALPs must be $\lesssim 5\times10^{52} \,\mathrm{erg}/s$ after the core-bounce, and this bound limits ALPs couplings. Contrary to the QCD axion models where all couplings are $\sim 1/f_a$, it has been shown recently that a radion/dilaton could have far different coupling strength to photons and to nucleons. This fact has raised a need to establish the limits on each coupling independently. The bounds from ALPs emission by nucleon-nucleon bremsstrahlung through a two-nucleon coupling and by the Primakoff process through a two-photon coupling are updated considering the total volume emission. I find the bounds on the two-photon coupling from the Primakoff process differ from previous bounds by an order of magnitude. Through the volume emission study, trapping regimes for $m_a\gtrsim10\,\mathrm{MeV}$ are also alleviated, which need to be probed by future experiments.