Is the ground state of Yang-Mills theory Coulombic?

Understand

We study trial states modelling the heavy quark-antiquark ground state in SU(2) Yang-Mills theory.

• A state describing the flux tube between quarks as a thin string of glue is found to be a poor description of the continuum ground state; the infinitesimal thickness of the string leads to UV artifacts which suppress the overlap with the ground state.
• Contrastingly, a state which surrounds the quarks with non-abelian Coulomb fields is found to have a good overlap with the ground state for all charge separations.
• In fact, the overlap increases as the lattice regulator is removed.