TMD PDF's: gauge invariance, RG properties and Wilson lines

Abstract

The UV divergences associated with transverse-momentum dependent (TMD) parton distribution functions (PDF) are calculated together with the ensuing one-loop anomalous dimensions in the light-cone gauge. Time-reversal-odd effects in the anomalous dimensions are observed and the role of Glauber gluons is discussed. A generalized renormalization procedure of TMD PDFs is proposed, relying upon the renormalization of contour-dependent operators with obstructions.

Comments: 4 pages, 1 figure. Talk presented at the International Workshop on Diffraction in High Energy and Nuclear Physics, La Londe-les-Maures, France, 9-14 Sept 2008. v2: 5 pages, preprint number and e-mail addresses added