Orateur
Description
During the gravitational collapse of a massive star, the proto-neutron-star core reaches extreme densities and temperatures, providing an environment in which QCD axions can be efficiently produced through their interactions with baryonic matter. Axion emission may contribute significantly to the cooling of the newly formed neutron star, and observations of supernova cooling, in particular from SN 1987A, therefore provide stringent constraints on axion-baryon couplings.
In this context, we construct an effective Lagrangian, based on symmetry principles, to systematically describe the interactions between axions and baryons. We investigate the leading axion production mechanisms in the proto-neutron-star medium, modeling baryon interactions via both spin-0 and spin-1 meson exchange; the vector-meson sector is implemented within the Hidden Local Symmetry framework, which we validate against hadron-scattering data.