Exploring Color Flows in TMDs: Disconnected Wilson Loops on the Lattice

One of the foremost goals of research into Quantum Chromodynamics (QCD) is to quantify the internal structure of the proton from first principles. Ab initio calculations of QCD matrix elements like transverse momentum distributions (TMDs) using lattice QCD are an essential part of achieving that goal. I present first explorations of effects on TMDs induced by the more intricate color flows in hadron-hadron collisions compared to the standard SIDIS and Drell-Yan processes. I analyze the correlations between proton, antiproton, and pion two-point functions with Wilson loops computed in lattice QCD. I consider Wilson loops of various shapes, and find a correlation between the two-point function and Wilson loop insertion which is significant and nonzero for narrow Wilson loops with widths up to 3 lattice spacings (0.342 fm) and for the first two momenta available on the lattice. This disconnected quark contribution will be combined in forthcoming work with connected three-point functions containing non-standard Wilson gauge link structures, to assemble the full modified TMD observables.