NONCLASSICAL ANALOGS OF SOLITONS IN QUANTUM-FIELD THEORY

The possible existence of quantum copies of classical soliton solutions that cannot exist if the effective Planck constant gamma of the theory tends to zero is discussed. In the framework of the standard expansion in square-root gamma, such nonclassical solitons have energy of order O(square-root gamma) and thus occupy an intermediate position between purely classical configurations and second-quantized degrees of freedom. Analytic calculations are made for the profile functions, masses, and stability of such configurations in the phi4 kink model.