Quantum scattering of charged solitons in the complex sine-Gordon model Original Research Article

The scattering of charged solitons in the complex sine-Gordon field theory is investigated. An exact factorizable S-matrix for the theory is proposed when the renormalized coupling constant takes the values λR2 = 4π/k for any integer k > 1: the minimal S-matrix associated with the Lie algebra αk−1. It is shown that the proposed S-matrix reproduces the leading semiclassical behaviour of all amplitudes in the theory and is the minimal S-matrix which is consistent with the semiclassical spectrum of the model. The results are completely consistent with the description of the complex sine-Gordon theory as the SU(2)/U(1) coset model at level k perturbed by its first thermal operator.