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Journal of High Energy Physics

, 2019:208 | Cite as

Low x physics as an infinite twist (G)TMD framework: unravelling the origins of saturation

  • Taiga Altinoluk
  • Renaud BoussarieEmail author
Open Access
Regular Article - Theoretical Physics
  • 28 Downloads

Abstract

We show how the formulations of low x physics involving Wilson line operators can be fully rewritten into an infinite twist TMD or GTMD framework, respectively for inclusive and exclusive observables. This leads to a perfect match between low x physics and moderate x formulations of QCD in terms of GTMDs, TMDs, GPDs or PDFs. We derive the BFKL limit as a kinematic limit and argue that beyond the Wandzura-Wilczek approximation, 3-body and 4-body unintegrated PFDs should be taken into account even in this regime. Finally we analyse how saturation should be understood as 3 distinct effects: saturation through non-linearities in the evolution equations at small x, saturation through multiple interactions with slow gluons as TMD gauge links, and saturation as the enhancement of genuine twist corrections.

Keywords

Heavy Ion Phenomenology 

Notes

Open Access

This article is distributed under the terms of the Creative Commons Attribution License (CC-BY 4.0), which permits any use, distribution and reproduction in any medium, provided the original author(s) and source are credited

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Copyright information

© The Author(s) 2019

Authors and Affiliations

  1. 1.National Centre for Nuclear ResearchWarsawPoland
  2. 2.Phyffics Department, Brookhaven National LaboratoryUptonU.S.A.

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