I am wondering if it makes sense to state that the upper limit is roughly 1012 eV (up to know the physics probed by the LHC seems to be pretty consistent with the SM) and the lower one is ... the upper bound for the photon mass (somewhere between 10-14 and 10-26 eV according to https://arxiv.org/abs/hep-ph/0306245).
If I understand well the argument in this article, one could say the larger value 10-14 eV comes from the Standard Model of particles (the photon would acquire mass by the Higgs mechanism, its large-scale behavior beeing effectively Maxwellian) while the smaller value 10-26 eV would come from the standard model of cosmology (the value of the galactic field today leading to this value from the hypothesis of a "Proca regime for all scales" ??).
Edit 06/12/13: I removed the expression : "domain of validity" that sounds too much like a mathematical closed interval. It is not adapted to the Standard Model because it is not a theory. I have chosen the formulation "phenomenological spectrum" to insist on the fact that this spectrum can be enriched with new particles whose masses are in the same energy range as the old ones.