Impacts of axion cooling on the direct detection of supernova axions

TL;DR

This paper reevaluates supernova axion detection prospects by performing long-term simulations that include axion emission feedback, revealing a significant reduction in expected axion signals compared to previous estimates.

Contribution

It introduces a comprehensive simulation approach that incorporates axion feedback effects, providing more accurate predictions for supernova axion detection.

Findings

Axion emission reduces proto-neutron star temperature.

Axion luminosity and detection event numbers are lower than previous estimates.

Nonlinear feedback of axion emission is crucial for accurate predictions.

Abstract

Core-collapse supernovae provide a unique opportunity to probe axions because they can be a copious source of the particles. It has recently been proposed that axion helioscopes can be used for the direct search for supernova axions if a supernova event appears within a few hundred parsecs. However, the event number of supernova axions has been estimated only within the post-process framework. In this study, we perform long-term supernova simulations for a 9.6M_sun star coupled with the axion emission to reevaluate the event number of axions detected by the helioscopes. We find that the additional cooling induced by the axion emission can significantly decrease the temperature in the proto-neutron star. As a result, the axion luminosity and hence the axion event number are reduced, compared with the result obtained through post-processing. Our result indicates that the nonlinear feedback of the axion emission is an essential factor to predict the axion detectability, and underscores the need for systematic simulation studies across various progenitor models.