Final State Interactions, T-odd PDFs & the Lensing Function

Abstract

It has been suggested that under certain approximations the Sivers effect can be described in terms of factorization of final state interactions and a spatial distortion of impact parameter space parton distribution; that is a convolution of the so-called lensing function and the impact parameter GPD $E$. In this approach the lensing function is calculated in a non-perturbative eikonal model. This enables a comparison between the a priori distinct Sivers function and the GPD $E$ which goes beyond the discussion of overall signs.Comment: 5 pages, 5 figures, misprints corrected: To appear in the Proceedings of the 10th Conference on the Intersection of Particle and Nuclear Physics (CIPANP 2009) San Diego, CA, 25-31 May 200