Infrared Divergences in $e^{+}{e}^{-}\to 2jets$ 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 $e^{+}{e}^{-}\to 2jets$ 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.

Comments: 23 pages, 5 figures. Published version. Minor additions and changes compared to v2