Threshold resummation S-factor for a system of two relativistic spinor particles with equal masses

Abstract

A new threshold resummation S-factor in quantum chromodynamics is obtained f o r a composite system of two relativistic spin-1/2 quarks having equal masses and interacting via a Coulomb-like chromodynamical potential. The pseudoscalar, vector, and pseudovector cases are considered. The present analysis is performed on the basis of the relativistic quasipotential approach in the Hamiltonian formulation of quantum field theory via a transition to the relativistic configuration representation for the case of a composite system formed by two relativistic spinor particles of equal masses.