Enhanced Supernova Axion Emission and Its Implications

We calculate the axion emission rate from reactions involving thermal pions in matter encountered supernovae and neutron star mergers, identify unique spectral features, explore their implications for astrophysics particle physics. find that it is about 2--5 times larger than nucleon-nucleon bremsstrahlung, which past studies was considered to be dominant process. The spectrum also found much harder. Together, rates higher energies imply a stronger bound on mass of QCD better prospects direct detection large underground neutrino detector nearby galactic supernova.