Can leptons give flavor to hadrons?

Abstract

We study the possibility that hadrons are composite state of leptons $l$ bound to strongly interacting matter. We find that with suitable binding forces one can achieve compatibility both with the observed weakness of low-energy interactions of leptons and the smallness of the ratio of hadronic to leptonic magnetic moments. We construct a semiphenomenological model of the low-lying hadrons, in which baryons are composed of three leptons bound to a universal extended baryonic core and mesons of an $l,\overline{l}$ pair bound to a universal mesonic core. The model has a number of interesting features: (i) It incorporates approximate SU(4) symmetry, with the weak neutral current providing a mechanism for avoiding a surplus of low-lying states. (ii) It requires the existence of observable cores, with masses which may be as low as 4-6 GeV; although the mesonic core would be very short-lived, the baryonic core could have a lifetime ranging from ${10}^{-16\mathrm{}}$ to ${10}^{-13\mathrm{}}$ sec. A baryonic core with two attached leptons, a "hadronic ion," would have a smaller mass and would, in principle, be detectable as an exceedingly narrow peak in antilepton-baryon mass plots. (iii) It requires that small deviations from $\mu -e$ universality exist in the decays of pseudoscalar mesons.