Can we measure the number of quark flavors without building an ultrahigh-energy accelerator?

Phenomenological implications of the nonapplicability of the Appelquist-Carazzone "decoupling" theorem for spontaneously broken gauge theories are discussed. In particular, if the Higgs scalar particle indeed exists and is available in the laboratory, then one can in principle determine the total number of quark flavors N₅ through measurements of (1) (H), the Higgs-particle partial decay rate into two photons, or (2) (pp+anything), the production cross section in p-p collisions, or (3) (e^+e^-e^+e^-), the production cross section in e^+e^- collisions via two-photon-exchange processes. Otherwise the number N₅ is inaccessible in the laboratory at finite energies.