Anomalous dimensions of transverse-momentum dependent parton distribution functions
Abstract
We discuss recent developments in the understanding of gauge-invariant transverse-momentum dependent (TMD) parton-distribution functions (PDF). We compute the leading-order -scheme anomalous dimension of such a quantity in the light-cone gauge and show that it receives a contribution that can be associated with a cusp obstruction at transverse light-cone infinity. This anomalous dimension is intimately related to expectation values composed of fields and eikonal factors along a cusped contour and is absent in covariant gauges. The implications of these findings are addressed and a modified definition of TMD PDFs is proposed.
Keywords
Cite
@article{arxiv.0808.3390,
title = {Anomalous dimensions of transverse-momentum dependent parton distribution functions},
author = {N. G. Stefanis and I. O. Cherednikov},
journal= {arXiv preprint arXiv:0808.3390},
year = {2008}
}
Comments
7 pages, 2 figures. Invited talk presented by the first author at International Workshop "Hadron Structure and QCD" (HSQCD'2008), June 30 - July 4, 2008, Gatchina, Russia (hsqcd.cls supplied)