In using transverse-momentum-dependent (TMD) parton densities and fragmentation functions, important non-perturbative information is at large transverse position bT. This concerns both the TMD functions and their evolution. Fits to high energy data tend to predict too rapid evolution when extrapolated to low energies where larger values of bT dominate. I summarize a new analysis of the issues. It results in a proposal for much weaker bT dependence at large bT for the evolution kernel, while preserving the accuracy of the existing fits. The results are particularly important for using transverse-spin-dependent functions like the Sivers function.
|Original language||English (US)|
|Journal||Proceedings of Science|
|State||Published - Jan 1 2015|
|Event||23rd International Workshop on Deep-Inelastic Scattering, DIS 2015 - Dallas, United States|
Duration: Apr 27 2015 → May 1 2015
All Science Journal Classification (ASJC) codes