strings as preons: does string theory allow muons to decay directly into e- + photon, given that the only difference between an electron and a muon, in string theory, is the string's tension? Of course, that's not how muons decay, (they decay into a W- boson, which decays into an electron and electron neutrino) but in string theory, all particles of the standard model are just different frequencies of one fundamental string. Graphically, it's not all that much different than Bilson's ribbon model, where all particles are made of braiding of a ribbon. In strings, all particles of the standard model are made of one string, whose frequency (tension) differs. If string theory is unable to prevent muons from decaying directly into electrons and photons, in contradiction to observation, doesn't this provide evidence that string theory is false? String theory has always struck me as a kind of preon theory. would string theory suffer from many of the problems preons theory have, including mass paradox and t'Hooft anomy matching? However string theory explains the decay of a fundamental string of a muon into a W- boson, rather than directly into an electron and photon, could that explanation be used for preon theory? However string theory gets around mass paradox or t'Hooft anomly matching, could those explanations be applied to proposed preon models?