Phenomenological Implications of Heavy AxionModels

摘要

Several models predict the existence of heavy (mass ～ MeV or so) pseudoscalar (axion-like) particles. This possibility is permitted only if the relation between the axion mass and the Peccei-Quinn constant is relaxed. Here we consider a possible phenomenological consequence of these models. After being pro-duced in the supernova core, these heavy axions would escape and a fraction of them would decay into photons before reaching the earth. We calculated the expected spectrum of these photons from the supernovae SN1987A and CAS A, in terms of the axion mass and the Peccei-Quinn constant f_a, and compared our results to the data from the FERMI Large Area Telescope. The analysis provides strong constraints on the allowed region in the axion parameter space for 100keV ≤ m_a ≤ 1 GeV. This mass region is completely excluded unless f_a > 10~(12)GeV. For axion masses ～ 100MeV, the constraint is stronger f_a > a few 10~(14)GeV.