Intrinsic Glue and Wilson lines within Dressed Quarks

Abstract

We construct a quark target model (QTM) to incorporate intrinsic glue into effective low-energy models of QCD, which often contain only quark degrees of freedom. This method guarantees the gauge invariance of observables order-by-order in the strong coupling. The quark and gluon PDFs for the dressed quarks are obtained in the QTM at leading order. We demonstrate gauge invariance of the results by comparing both covariant and light cone gauges, with the former including an explicit Wilson line contribution. A key finding is that in covariant gauges the Wilson line can carry a significant amount of the light cone momentum. With coupling strength ${\alpha }_s=0.5$ and dressed quark mass $M_q=0.4$GeV, we find quark and gluon momentum fractions of ${⟨x⟩}_q=0.81$ and ${⟨x⟩}_g=0.19$, where the Wilson line contribution to the quark momentum fraction is $-0.18$. We use the on-shell renormalization scheme and find that at one-loop this Wilson line contribution does not depend on the covariant gauge but does vanish in light cone gauge as expected. This result demonstrates that it is crucial to account for Wilson line contributions when calculating quantum correlation functions in covariant gauges. We also consider the impact of a gluon mass using the gauge invariant formalism proposed by Cornwall, and combine these QTM results with two quark-level models to obtain quark and gluon PDFs for the pion.

arXiv comment12 pages

References in corpus (31)

• Parton Physics on Euclidean Lattice
• Baryons as relativistic three-quark bound states
• Quasi-PDFs, momentum distributions and pseudo-PDFs
• Explanation and Prediction of Observables using Continuum Strong QCD
• Exploring hadrons' partonic structure using ab initio lattice QCD calculations
• Nucleon Parton Distributions at Low Normalization Point in the Large N_c Limit
• Infrared propagators of Yang-Mills theory from perturbation theory
• Analysis of a quenched lattice-QCD dressed-quark propagator
• Extended NJL Model for light and heavy mesons without q-qbar thresholds
• Factorization Theorem Relating Euclidean and Light-Cone Parton Distributions
• First Monte Carlo global QCD analysis of pion parton distributions
• Unpolarized and polarized quark distributions in the large-Nc limit
• Asymptotic Scaling and Infrared Behavior of the Gluon Propagator
• Lattice Gluon and Ghost Propagators, and the Strong Coupling in Pure SU(3) Yang-Mills Theory: Finite Lattice Spacing and Volume Effects
• Running Gluon Mass from Landau Gauge Lattice QCD Propagator
• Valence parton distribution of pion from lattice QCD: Approaching continuum
• Pion valence quark distribution from current-current correlation in lattice QCD
• Diquark confinement in an extended NJL model
• Parton Distribution Functions from Ioffe Time Pseudodistributions from Lattice Calculations: Approaching the Physical Point
• Techniques for one-loop calculations in constrained differential renormalization
• Role of diquark correlations and the pion cloud in nucleon elastic form factors
• Transversity quark distributions in a covariant quark-diquark model
• Nucleon quark distributions in a covariant quark-diquark model
• The dynamical equation of the effective gluon mass
• Distinguishing Quarks and Gluons in Pion and Kaon PDFs
• TMDs of Spin-one Targets: Formalism and Covariant Calculations
• The analytic structure of the lattice Landau gauge gluon and ghost propagators
• Spatial and Momentum Imaging of the Pion and Kaon
• Charge Symmetry Breaking Effects in Pion and Kaon Structure
• Quark spin and orbital angular momentum from proton GPDs
• Impact of DCSB and dynamical diquark correlations on proton GPDs

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