Equality of Two Definitions for Transverse Momentum Dependent Parton Distribution Functions

Abstract

We compare recent, seemingly different, approaches to TMD-factorization (due to Echevarria, Idilbi, and Scimemi and to Collins), and show that they are the same, apart from an apparent difference in their definition of the \MSbar{} renormalization scheme.

Comments: Fixed arrows on figures, added comments to the summary; 12 pages, 3 figures