Heavy-quark solitons: towards realistic masses

Abstract

A generalization of the effective meson lagrangian possessing the heavy-quark symmetry to finite meson masses is employed to study the meson mass dependence of the spectrum of S-and P-wave baryons containing one heavy quark or anti-quark. These baryons are described as respectively heavy mesons or anti-mesons bound in the background of a soliton, which is constructed from light mesons. No further approximation is made to solve the bound-state equation. For special cases it is shown that the boundary conditions, which have to be satisfied by the bound-state wave functions and stem from the interaction with the light mesons, may impose additional constraints on the existence of bound states when finite masses are assumed. Two types of models supporting soliton solutions for the light mesons are considered: the Skyrme model of pseudoscalars only as well as an extension containing also light vector mesons. It is shown that only the Skyrme model with vector mesons provides a reasonable description of both light and heavy baryons. Kinematical corrections to the bound-state equations are included in the discussion.