White dwarfs as a probe of exceptionally light QCD axions

• DOI: 10.48550/arxiv.2211.02661
• Publication Date: 2024-05-22
• Authors: Reuven Balkin; Javi Serra; Konstantin Spring...; Stefan Stelzl; Andreas Weiler
• Keywords: High Energy Astrophysical Phenomena (astro-ph.HE); FOS: Physical sciences; 01 natural sciences; Mass-Distribution; High Energy Physics - Phenomenology; High Energy Physics - Phenomenology (hep-ph); Astrophysics - Solar and Stellar Astrophysics; 0103 physical sciences; Thermodynamics; Catalog; Astrophysics - High Energy Astrophysical Phenomena; Solar and Stellar Astrophysics (astro-ph.SR)

We study the effects of exceptionally light QCD axions on the stellar configuration of white dwarfs. At finite baryon density, the nonderivative coupling of the axion to nucleons displaces the axion from its in-vacuum minimum, which implies a reduction of the nucleon mass. This dramatically alters the composition of stellar remnants. In particular, the modifications of the mass-radius relationship of white dwarfs allow us to probe large regions of unexplored parameter space without requiring that axions are dark matter. Published by the American Physical Society 2024