Heavy fermion stabilization of solitons in 1+1 dimensions

We find static solitons stabilized by quantum corrections in a (1 + 1)-dime nsional model with a scalar field chirally coupled to fermions, This model does not support classical solitons. We compute the renormalized energy fun ctional including one-loop quantum corrections. We carry out a variational search for a configuration that minimizes the energy functional. We find a nontrivial configuration with fermion number whose energy is lower than the same number of free fermions quantized about the translationally invariant vacuum. In order to compute the quantum corrections for a given background field we use a phase-shift parameterization of the Casimir energy. We iden tify orders of the Born series for the phase shift with perturbative Feynma n diagrams in order to renormalize the Casimir energy using perturbatively determined counterterms. Generalizing dimensional regularization, we demons trate that this procedure yields a finite and unambiguous energy functional (C) 2000 Elsevier Science B.V. All rights reserved.