Renormalization and Composite Effects in the Lee Model

Abstract

We consider the version of the Lee model with relativistic kinematics. The mass renormalization of the V particle, described in purely field‐theoretic terms, is a nonlocal effect. We discuss the composite limit of the model. The natural choice of composite field is nonlocal in the elementary constituents. In the composite limit, Z₁ does not vanish. The Hilbert‐space formalism of the composite theory is not equivalent to that of an N‐θ theory with a four‐particle interaction. All these results are cutoff independent.