Non-perturbative strong coupling at timelike momenta

Abstract

We compute the strong coupling constant of Landau gauge QCD in the full complex momentum plane, both directly and via spectral reconstruction. In particular, we consider the Taylor coupling given by the product of ghost and gluon dressing functions. Assuming spectral representations for the latter, we first show that also the coupling obeys such a representation. The subsequent spectral reconstruction of the coupling data, obtained from 2+1 flavour lattice QCD results for the ghost and gluon, is based on a probabilistic inversion of this representation using Gaussian process regression with analytically enforced asymptotics. In contradistinction, our direct calculation relies on earlier reconstruction results for the ghost and gluon spectral functions themselves, as well as data obtained in functional QCD. Apart from its relevance for studies of resonances or scattering processes, the calculation also serves as a non-trivial benchmark of our reconstruction approach. The results show remarkable agreement, testifying to the reliability of the method.

arXiv comment13 pages, 6 figures

References in corpus (62)

• A Method for Simulating Chiral Fermions on the Lattice
• Chiral Fermions from Lattice Boundaries
• Maximum Entropy Analysis of the Spectral Functions in Lattice QCD
• Lattice gluodynamics computation of Landau-gauge Green's functions in the deep infrared
• The QCD phase structure at finite temperature and density
• Domain wall QCD with physical quark masses
• Physical Results from 2+1 Flavor Domain Wall QCD and SU(2) Chiral Perturbation Theory
• Landau gauge Yang-Mills correlation functions
• Non-perturbative quark, gluon and meson correlators of unquenched QCD
• A novel Bayesian approach to spectral function reconstruction
• Quark flavour effects on gluon and ghost propagators
• Three-point vertices in Landau-gauge Yang-Mills theory
• Process-independent strong running coupling
• Ghost-gluon running coupling, power corrections and the determination of ${\Lambda }_{\overline{\mathrm{MS}}}$
• Towards the infrared limit in SU(3) Landau gauge lattice gluodynamics
• Domain Wall QCD with Near-Physical Pions
• Exploratory study of three-point Green's functions in Landau-gauge Yang-Mills theory
• Nevanlinna Analytical Continuation
• 2+1 flavor domain wall QCD on a (2 fm)^3 lattice: light meson spectroscopy with Ls = 16
• Positivity violation for the lattice Landau gluon propagator
• Infrared Behavior of the Gluon Propagator on a Large Volume Lattice
• On the zero crossing of the three-gluon vertex
• Reconstructing the gluon
• Effective charge from lattice QCD
• Artificial Neural Network Approach to the Analytic Continuation Problem
• Fully coupled functional equations for the quark sector of QCD
• Gluon spectral functions and transport coefficients in Yang--Mills theory
• The strong running coupling from the gauge sector of Domain Wall lattice QCD with physical quark masses
• Gluon propagator and three-gluon vertex with dynamical quarks
• Mobius Fermions: Improved Domain Wall Chiral Fermions
• Refining the detection of the zero crossing for the symmetric and asymmetric three-gluon vertices
• Reconstructing the thermal Green functions at real times from those at imaginary times
• Reconstructing QCD Spectral Functions with Gaussian Processes
• Analytic continuation via domain-knowledge free machine learning
• Further Evidence For Zero Crossing On The Three Gluon Vertex
• Discretization effects on renormalized gauge-field Green's functions, scale setting and gluon mass
• Spectral Reconstruction with Deep Neural Networks
• Analytical Continuation of Matrix-Valued Functions: Carathéodory Formalism
• The decay constants ${\mathbf{f}}_{\mathbf{D}}$ and ${\mathbf{f}}_{{\mathbf{D}}_{\mathbf{s}}}$ in the continuum limit of ${\mathbf{N}}_{\mathbf{f}}=2+1$ domain wall lattice QCD
• Does The Lattice Zero Momentum Gluon Propagator for Pure Gauge SU(3) Yang-Mills Theory Vanish in the Infinite Volume Limit?
• Ghost spectral function from the spectral Dyson-Schwinger equation
• Spectral functions in the ${\varphi }^4$-theory from the spectral DSE
• Bayesian Approach to Inverse Problems: an Application to NNPDF Closure Testing
• Spectral representation of lattice gluon and ghost propagators at zero temperature
• Gluon-propagator functional form in the Landau gauge in SU(3) lattice QCD: Yukawa-type gluon propagator and anomalous gluon spectral function
• Asymptotic behavior of the ghost propagator in SU3 lattice gauge theory
• Ghost dynamics in the soft gluon limit
• Infrared facets of the three-gluon vertex
• A test on analytic continuation of thermal imaginary-time data
• Analytic Perturbation Theory: A New Approach to the Analytic Continuation of the Strong Coupling Constant ${\alpha }_S$ into the Timelike Region
• Towards a Nonperturbative Foundation of the Dipole Picture: II. High Energy Limit
• Quark-gluon vertex from Nf=2 lattice QCD
• Bayesian inference of non-positive spectral functions in quantum field theory
• Infrared Gluon Propagator from lattice QCD: results from large asymmetric lattices
• Spontaneous chiral symmetry breaking in the massive Landau gauge: realistic running coupling
• Towards a Nonperturbative Foundation of the Dipole Picture: I. Functional Methods
• Parton distribution functions from lattice QCD using Bayes-Gauss-Fourier transforms
• Non-perturbative constraints on the quark and ghost propagators
• Collective charge excitations and the metal-insulator transition in the square lattice Hubbard-Coulomb model
• Neural network approach to reconstructing spectral functions and complex poles of confined particles
• Strong coupling constant to four loops in the analytic approach to QCD
• Källén-Lehmann Spectral Representation of the Scalar SU(2) Glueball

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