Muonic Boson Limits: Supernova Redux

Understand

We derive supernova (SN) bounds on muon-philic bosons, taking advantage of the recent emergence of muonic SN models.

• Our main innovations are to consider scalars $\phi$ in addition to pseudoscalars $a$ and to include systematically the generic two-photon coupling $G_{\gamma\gamma}$ implied by a muon triangle loop.
• This interaction allows for Primakoff scattering and radiative boson decays.
• The globular-cluster bound $G_{\gamma\gamma}<0.67\times10^{-10}~{\rm GeV}^{-1}$ derived for axion-like particles carries over to the muonic Yukawa couplings as $g_a<3.1\times10^{-9}$ and $g_\phi< 4.6\times10^{-9}$ for $m_{a,\phi}\lesssim 100$ keV, so SN arguments become interesting mainly for larger masses.