CHIRAL SOLITONS WITH QUARKS AND COMPOSITE MESONS

We explore the development of a nontopological soliton model for baryons in which effective meson fields are generated from extended quark-antiquark pairs within a nonlocal model of Nambu-Jona-Lasinio type. Meson kinetic and potential energies arise from the Dirac sea. Only scalar-isoscalar and pseudoscalar-isovector meson fields are retained. Functional methods and bilocal field techniques are employed and we work to lowest order in loops for the retained degrees of freedom. We identify a mean-field approximation from the effective action obtained through a Legendre transformation incorporating a chemical-potential constraint. This fixes the baryon number in terms of valence quark configurations and thereby induces a classical configuration for the meson fields. After a localization of the meson sector of the effective action, the model is of the linear sigma type with a nonlocal quark-meson vertex due to the composite extended nature of the internally generated meson fields. With a self-confining dynamical quark mass, the classical meson fields provide a region where quarks can propagate and have a defined eigenenergy. A simple model illustration of this mechanism is provided.