Light-front QCD. I. Role of longitudinal boundary integrals.

Abstract

In this first part in a series of papers on light-front QCD, we address the global properties of light-front canonical structure. In the light-front canonical gauge theory, the elimination of unphysical gauge degrees of freedom leads to a set of boundary integrals which are associated with the light-front infrared singularity. We find that a consistent treatment of the boundary integrals leads to the cancellation of the light-front linear infrared divergences. For physical states, the requirement of finite energy density in the light-front gauge (${A}_{a}^{+}=0$) results in equations which determine the asymptotic behavior of the transverse (physical) gauge degrees of freedom at longitudinal boundary. These asymptotic fields are generated by the boundary integrals and they involve nonlocal behavior in the transverse direction that leads to nonlocal forces which may be the source of QCD confinement.