Infrared divergences in e+e−→2 jets in the light front coherent state formalism

Abstract

We study infrared (IR) divergences in light front quantum chromodynamics using a coherent state basis in light front time-ordered Hamiltonian perturbation theory. In computation of the S-matrix elements in Hamiltonian formalism, the IR divergences appear in the form of vanishing energy denominators. We consider the process ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}2$ jets at $\mathcal{O}({g}^{2})$ in strong coupling, construct the coherent state representing the outgoing particles, and explicitly show that the ``true'' IR divergences cancel to this order when the matrix elements are calculated between coherent states instead of Fock states.