The asymptotics of n-point Green's function at large external momenta is obtained in the exponentiated form using the Fock-Feynman-Schwinger representation for propagators in the external field. The method is applied to gauge theories such as QCD and QED, and the Sudakov form-factor is calculated as an example in QED and meson form-factor in QCD. Nonperturbative contributions can be conveniently included, as it is demonstrated in the example of the confinement correction to the form-factor.
Categories: hep-ph