Collins-Soper Kernel for TMD Evolution from Lattice QCD

The Collins-Soper kernel relates transverse momentum-dependent parton distribution functions (TMDPDFs) at different energy scales. For small parton transverse momentum q(T) - Lambda(QCD), this kernel is nonperturbative and can only be determined with controlled uncertainties through experiment or firstprinciples calculations. This work presents the first exploratory determination of the Collins-Soper kernel using the lattice formulation of quantum chromodynamics. In a quenched calculation, the N-f = 0 kernel is determined at scales in the range 250 MeV < q(T) < 2 GeV, and an analysis of the remaining systematic uncertainties is undertaken.