Baryon decays in a quark model with chromodynamics

Abstract

Quark models of hadrons are tested in a very limited way when only their spectroscopy is compared with experiment; at least equally important tests arise from examining the predicted internal structure of the hadrons via analysis of their decay amplitudes. We present here a compilation of one of the most extensive calculations of baryon amplitudes to date, encompassing the pseudoscalar and photon couplings of the states associated with up to two orbital or one radial excitation in the nonrelativistic quark model. These amplitudes are then combined with the baryon compositions predicted by a quark model incorporating some of the features expected to arise from quantum chromodynamics. The result is to generate a set of baryon amplitudes which (1) resolve the problem of missing resonances by essentially decoupling a very large number of states from partial-wave analyses and (2) leave those resonances which remain in remarkable correspondence to the observed states in both their masses and decay amplitudes.