Muonic boson limits: Supernova redux

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 x 10(-10) GeV-1 carries over to the muonic Yukawa couplings as g(a) < 3.1 x 10(-9) and g(phi) < 4.6 x 10(-9) for m(a,phi) less than or similar to 100 keV, so SN arguments become interesting mainly for larger masses. If bosons escape freely from the SN core the main constraints originate from SN 1987A gamma rays and the diffuse cosmic gamma-ray background. The latter allows at most 10(-4) of a typical total SN energy of E-SN similar or equal to 3 x 10(53) erg to show up as gamma rays, for m(a,phi) greater than or similar to 100 keV implying g(a) less than or similar to 0.9 x 10(-10) and g(phi) less than or similar to 0.4 x 10(-10). In the trapping regime the bosons emerge as quasi-thermal radiation from a region near the neutrino sphere and match L-nu for g(a,phi) similar or equal to 10(-4). However, the 2 gamma decay is so fast that all the energy is dumped into the surrounding progenitor-star matter, whereas at most 10(-2)ESN may show up in the explosion. To suppress boson emission below this level we need yet larger couplings, g(a) greater than or similar to 2 x 10(-3) and g(phi) greater than or similar to 4 x 10(-3). Muonic scalars can explain the muon magnetic-moment anomaly for g(phi) similar or equal to 0.4 x 10(-3), a value hard to reconcile with SN physics despite the uncertainty of the explosion-energy bound. For generic axionlike particles, this argument covers the "cosmological triangle" in the Ga-gamma gamma-m(a) parameter space.