Inelastic Effects in the Lee–Yang Model

In this work, the theories in which the renormalization group flow passes near the Lee–Yang critical point are analyzed. Such theories can be described effectively as perturbations of the massive Lee–Yang theory by irrelevant operators. The perturbation induced by one of the descendants of a single nontrivial primary operator $$\varphi $$ of the theory is considered. It is shown that such a perturbation breaks the integrability of the system. The inelastic scattering cross section for the corresponding $$2 \to 3$$ process with the generation of particles is calculated up to the normalization factor. In particular, the asymptotic forms of the cross sections are calculated for high energies and above the particle generation threshold.