Definition and Evolution of Transverse Momentum Distributions

Abstract

We consider the definition of unpolarized transverse-momentum-dependent parton distribution functions while staying on-the-light-cone. By imposing a requirement of identical treatment of two collinear sectors, our approach, compatible with a generic factorization theorem with the soft function included, is valid for all non-ultra-violet regulators (as it should), an issue which causes much confusion in the whole field. We explain how large logarithms can be resummed in a way which can be considered as an alternative to the use of Collins-Soper evolution equation. The evolution properties are also discussed and the gauge-invariance, in both classes of gauges, regular and singular, is emphasized.

15 pages. Proceedings of QCD Evolution Workshop, May 14-17 2012, JLAB

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Cited by in corpus (6)

• Model Independent Evolution of Transverse Momentum Dependent Distribution Functions (TMDs) at NNLL
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• Top quark pair production at small transverse momentum in hadronic collisions
• Sivers effect and the single spin asymmetry A_N in p(transv. pol.) p --> h X processes
• Resummation Prediction on Higgs and Vector Boson Associated Production with a Jet Veto at the LHC
• Rapidity Logarithms in SCET Without Modes