Integrable perturbations of CFT with complex parameter: the $M_{3/5}$ model and its generalizations

F. Ravanini, M. Stanishkov, R. Tateo

We give evidence, by use of the Thermodynamic Bethe Ansatz approach, of the existence of both massive and massless behaviours for the ${\varphi }_{2,1}$ perturbation of the $M_{3,5}$ non-un…