Constraining Heavy Axionlike Particles by Energy Deposition in Globular Cluster Stars
Giuseppe Lucente, O. Straniero, Pierluca Carenza, Maurizio Giannotti, Alessandro Mirizzi
Abstract
Heavy axionlike particles (ALPs) with masses up to a few 100 keV and coupled with photons can be efficiently produced in stellar plasmas. We present a new ``ballistic'' recipe that covers both the energy-loss and energy-transfer regimes, and we perform the first dedicated simulation of Globular Cluster stars including the ALP energy transfer. This argument allows us to constrain ALPs with ${m}_{a}\ensuremath{\lesssim}0.4\text{ }\text{ }\mathrm{MeV}$ and ${g}_{a\ensuremath{\gamma}}\ensuremath{\simeq}{10}^{\ensuremath{-}5}\text{ }\text{ }{\mathrm{GeV}}^{\ensuremath{-}1}$, probing a section of the ALP parameter space informally known as the ``cosmological triangle''. This region is particularly interesting since it has been excluded only using standard cosmological arguments that can be evaded in nonstandard scenarios.