Baryon-Meson Couplings in the $q\bar{q}$ Pair-Creation Quark Model. III

Abstract

We continue the previous quark-model studies of qq pair-creation transition amplitudes for P-wave baryons and evaluate the energy shifts of compact 3q energies due to the couplings to baryon-meson composite configurations. These baryon-meson configurations are described by the antisymmetrized (3q)(qq) cluster-model wave functions composed of simple harmonic oscillator functions and the plane-wave relative motion. The rich spin-flavor SU6 structure of the transition amplitudes due to the off-shell Fermi-Breit interaction and threshold effects of various baryon-meson configurations predict non-uniform energy shifts for each member of the SU6 supermultiplet, thus yielding a possible resolution of the missing LS force problem in the P-wave baryons. A typical example is given for a slightly modified off-shell Fermi-Breit interaction in which the sign of the SU6 breaking term is inverted. Except for the flavor-singlet Λ resonances at the lowest energies, the energy spectrum and the mixing features of the spin S = 1/2 and 3/2 resonances are well reproduced together with the partial decay widths to pseudo-scalar mesons and ground-state baryons.