Speaker
Description
The Collins-Soper kernel is a key, universal quantity that relates transverse momentum dependent distributions (TMDs) at different rapidity scales through an evolution equation. The CS kernel may be obtained through the TMD soft function by formulating the Wilson line in terms of 1-dimensional auxiliary fermion fields on the lattice. The complex auxiliary field directional vectors can be mapped directly to the Wilson line rapidity in Collins' definition of the TMD soft function. We find that our computation can be carried out at high statistical precision, and obtain results with uncertainties that are comparable with state of the art lattice results. Our uncertainties are dominated by the perturbative matching that is necessary for our method. Moreover, we find that the CS kernel has a plateau in the large $b_\perp$ region.