Form-factor interpretation of kink solutions to the nonlinear sigma model

Kink solutions to the SU(2) nonlinear sigma model in one time and two space dimensions are interpreted as matrix elements of the meson fields between states of a new, heavy, particle. These new particles are stable and carry a topologically conserved charge N (N = integer) which is odd under both charge conjugation and time reversal. To lowest order in a weak-coupling expansion their mass is proportional to vertical-barNvertical-bar. Moreover, consistency of the form-factor interpretation is achieved by assigning to the particles an angular momentum L and electric charge Q obeying L = +- NQ. More general solutions, apparently describing multiparticle states, are also discussed