Lightest flavor-singlet qqq baryons as witnesses to color

Abstract

We present a new computation in a field-theoretical model of Coulomb-gauge QCD of the first radial and angular excitations of a qqq system in an SU(3) flavor-singlet state, Lambda(S). The traditional motivation for the study is that the absence of flavor singlets in the lowest-lying spectrum is a direct consequence of the color degree of freedom. [The calculation is tested with decuplet baryons Delta(1232) and Omega(1672).] We also analyze decay branching fractions of the flavor-singlet baryon for various masses with the simplest effective Lagrangians.