GROUND-STATE CHARGE OF O(3) NONLINEAR SIGMA-MODEL SOLITONS IN 2+1 DIMENSIONS

The ground state charge of (2 + 1)-dimensional nonlinear sigma model s olitons is calculated by & combination of adiabatic method and spectra l flow analysis. Induced charge is calculated by evolving adiabaticall y the fields from a vacuum having a background field which has spectra l symmetry. The spectral flow is calculated by analyzing the bound sta te spectrum. It is shown that the ground state change gets contributio n only from the lowest angular momentum states and is discontinuous at the fermion mass. It is also shown that the ground state charge is in dependent of the way in which the final configuration is obtained.