>>11885956just to follow up . i looked up the Landau-Yang theorem on wikipedia and it is important in the idea that the new boson is not spin 1. the observed decays would be prohibited if it were spin 1.
however, the standard model higgs mechanism does more than simple decays to two photons. its real job in the standard model is to give mass to all the particles. the Higgs does that job by having a vev (which stands for “Vacuum Expectation Value”). this vev directly causes the W and Z to be massive, no tricks involved. also, the theory, if you flesh it out, not only requires the higgs to have a vev for that, but also for it requires a nonzero veg to give mass to all other particles.
this implies that the more massive a particle is, then the higgs will want to decay to that particle proportionally , because the coupling to the higgs (Yukawa couplings) is what generates mass. these couplings also dictate how the higgs boson decays. and many experiments have been done that show the higgs decays exactly as expected if you think the higgs generates mass.
and all this relies on the higgs having a nonzero vev. and that’s impossible if you believe in Lorentz invariance (a synonym for “special relativity “) unless the higgs has spin 0
