MASS SCALE IN THE SINE-GORDON MODEL AND ITS REDUCTIONS

Known Bethe ansatz results about the sine-Gordon factorized scattering are reinterpreted in terms of perturbed conformal field theory. We ob tain an exact relation between the ultraviolet and asymptotic scales ( i.e. between the dimensional coupling constant and the soliton mass) a nd an explicit expression for the vacuum energy. The reduction techniq ue then permits one to relate exactly the coupling constants and the m ass scales in the Phi(13)-perturbed minimal CFT models. The preasympto tically free situation at beta(2) near 8 pi is discussed on a prelimin ary footing.