TMD factorization and the gluon distribution in high energy QCD

Abstract

This paper is a part of a series of works where we in detail examine the concept of Transverse Momentum Dependent (TMD), or k_T, factorization, which is frequently encountered in the literature and is widely used in the phenomenological applications of QCD at very high energies. We address the question of what exactly factorization is, as it is meant in different contexts and formalisms, and we compare the formalisms to each other. We clarify some basic concepts regarding factorization and how it exactly is applied in high energy QCD, and we make important notes on some key and fundamental points that are often overlooked. We offer an extensive analysis of single inclusive particle production, and we analyze the TMD gluon distribution that plays a pivotal role in high energy QCD.

arXiv comment80 pages v2: Few typos corrected, and references added

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Cited by in corpus (20)

• Gluon saturation in dijet production in p-Pb collisions at Large Hadron Collider
• Azimuthal asymmetries for quark pair production in pA collisions
• Dynamical entropy of dense QCD states
• Transition between soft physics at LHC and low-x physics at HERA
• Drell-Yan lepton pair production at LHC and TMD quark densities of the proton
• LHC soft physics and TMD gluon density at low x
• Higgs boson production in high energy proton-nucleus collisions
• TMD PDFs: a Monte Carlo implementation for the sea quark distribution
• Employing RHIC and LHC data to determine TMD gluon density in a proton
• Collinearity approximations and kinematic shifts in partonic shower algorithms
• Three jet production and gluon saturation effects in p-p and p-Pb collisions within high-energy factorization
• Significance of non-perturbative input to TMD gluon density for hard processes at LHC
• Loop space and evolution of the light-like Wilson polygons
• Nonperturbative corrections and showering in NLO-matched event generators
• Next-to-Leading Order correction to inclusive particle spectra in the Color Glass Condensate framework
• Inability to find justification of a $k_T$-factorization formula by following chains of citations
• Unintegrated gluon distributions for forward jets at LHC
• TMD parton densities in associated real and virtual photon and jet production at LHC
• Soft Gluons and Jets at the LHC
• TMD PDFs in Drell-Yan lepton pair production at LHC