Baryons in QCD are three-quark color-singlet bound states and any two of the quarks are necessarily in a 3¯ color state. These 3¯ diquark states form bound states which, if they are of sufficiently low mass, will play a significant dynamical role in the structure of baryons. Here we estimate these diquark masses by using an approximate homogeneous Bethe-Salpeter (BS) equation. A new technique for determining the mass of a bound state from the BS equation, which avoids the need to numerically solve the integral equation, is introduced and its validity demonstrated by application to various meson states. Our diquark mass values are compared with those determined from analysis of experimental data on inclusive production of protons.

• Received 17 February 1987

DOI:https://doi.org/10.1103/PhysRevD.36.2804