Electrobaryonic axion: hair of neutron stars
Abstract
Various Beyond the Standard Model extensions predict axion-like particles characterized by quantum anomalies. The anomalous processes can also be sourced by global currents in the model. While extensive research has explored the impact of these anomalies in QCD, their implications for BSM axion-like particles remain largely uncharted. In this work, we investigate the consequences of anomaly-induced processes in finite boundary systems. In specific we focus on systems with finite baryon chemical potential and background magnetic fields. The study encompasses two key systems: a simplified one-dimensional toy model, serving as a practical foundation for axion production and detection in experimental setups, and neutron stars, characterized by potent magnetic fields and higher chemical potentials.