The Unitary Clothing Transformation Method in Quantum Field Theory. Renormalization of Coupling Constant

Abstract

Applying the unitary clothing transformation method in the model of charged spinless nucleons and neutral mesons interacting via the three-linear Yukawa-type coupling, the expression for the charge shift in the third order in the coupling constant is derived. Being determined off the energy shell, the ex-pression can be reduced on the energy shell to the explicitly covariant form, providing the independence of the particle momenta. Comparison with the cor-responding result of the Dyson covariant perturbation theory is performed by es-tablishing the link between the old-fashioned perturbation theory and the cloth-ing approach.