Towards the determination of the gluon helicity distribution in the nucleon from lattice quantum chromodynamics

Abstract

We present the first exploratory lattice quantum chromodynamics (QCD) calculation of the polarized gluon Ioffe-time pseudo-distribution in the nucleon. The Ioffe-time pseudo-distribution provides a frame-independent and gauge-invariant framework to determine the gluon helicity in the nucleon from first principles. We employ a high-statistics computation using a $32^3\times 64$ lattice ensemble characterized by a $358$ MeV pion mass and a $0.094$ fm lattice spacing. We establish the pseudo-distribution approach as a feasible method to address the proton spin puzzle with successive improvements in statistical and systematic uncertainties anticipated in the future. Within the statistical precision of our data, we find a good comparison between the lattice determined polarized gluon Ioffe-time distribution and the corresponding expectations from the state-of-the-art global analyses. We find a hint for a nonzero gluon spin contribution to the proton spin from the model-independent extraction of the gluon helicity pseudo-distribution over a range of Ioffe-time, $\nu \lesssim 9$.

Version to be published in Phys. Rev. D, 24 pages, 13 figures

References in corpus (40)

• Perturbative analysis of the gradient flow in non-abelian gauge theories
• Extraction of Spin-Dependent Parton Densities and Their Uncertainties
• High-precision scale setting in lattice QCD
• On the generalized eigenvalue method for energies and matrix elements in lattice field theory
• A first unbiased global determination of polarized PDFs and their uncertainties
• A novel quark-field creation operator construction for hadronic physics in lattice QCD
• Evidence for polarization of gluons in the proton
• Large-Momentum Effective Theory
• Exploring hadrons' partonic structure using ab initio lattice QCD calculations
• S and D-wave phase shifts in isospin-2 pi pi scattering from lattice QCD
• Exclusive processes in position space and the pion distribution amplitude
• Pion Valence Quark Distribution from Matrix Element Calculated in Lattice QCD
• Complete flavor decomposition of the spin and momentum fraction of the proton using lattice QCD simulations at physical pion mass
• Valence parton distribution of pion from lattice QCD: Approaching continuum
• Reconstructing parton distribution functions from Ioffe time data: from Bayesian methods to Neural Networks
• Measurement of Azimuthal Asymmetries With Respect To Both Beam Charge and Transverse Target Polarization in Exclusive Electroproduction of Real Photons
• Parton Distribution Functions from Ioffe Time Pseudodistributions from Lattice Calculations: Approaching the Physical Point
• Glue spin and helicity in proton from lattice QCD
• Isovector parton distribution functions of the proton on a superfine lattice
• Lattice QCD Determination of the Bjorken-$x$ Dependence of Parton Distribution Functions at Next-to-next-to-leading Order
• Confronting lattice parton distributions with global QCD analysis
• Flavor non-singlet parton distribution functions from lattice QCD at physical quark masses via the pseudo-distribution approach
• Distribution Amplitudes of $K^{\ast }$ and $\varphi$ at Physical Pion Mass from Lattice QCD
• Lattice continuum-limit study of nucleon quasi-PDFs
• Neural-network analysis of Parton Distribution Functions from Ioffe-time pseudodistributions
• How well do we know the gluon polarization in the proton?
• Flavor decomposition for the proton helicity parton distribution functions
• Flavor decomposition of the nucleon unpolarized, helicity and transversity parton distribution functions from lattice QCD simulations
• The pion and kaon $⟨x^3⟩$ from lattice QCD and PDF reconstruction from Mellin moments
• Nucleon Gluon Distribution Function from 2+1+1-Flavor Lattice QCD
• Complementarity of experimental and lattice QCD data on pion parton distributions
• Parton distribution functions beyond leading twist from lattice QCD: The $h_L(x)$ case
• RI/MOM renormalization of the quasi-PDF in lattice regularization
• Parton physics from a heavy-quark operator product expansion: Lattice QCD calculation of the second moment of the pion distribution amplitude
• Gluon distributions and their applications to Ioffe-time distributions
• Continuum limit of parton distribution functions from the pseudo-distribution approach on the lattice
• Distillation at High-Momentum
• From Ji to Jaffe-Manohar orbital angular momentum in Lattice QCD using a direct derivative method
• The Positive-Parity Baryon Spectrum and the Role of Hybrid Baryons
• Polarized Gluon Pseudodistributions at Short Distances

Cited by in corpus (17)

• 50 Years of Quantum Chromodynamics
• The Present and Future of QCD
• Gluon distributions in the proton in a light-front spectator model
• Pion Valence-Quark Generalized Parton Distribution at Physical Pion Mass
• Towards Unpolarized GPDs from Pseudo-Distributions
• Gluon Parton Distribution of the Nucleon from 2+1+1-Flavor Lattice QCD in the Physical-Continuum Limit
• Non-singlet quark helicity PDFs of the nucleon from pseudo-distributions
• Moments of parton distribution functions of any order from lattice QCD
• Generalized parton distributions from the pseudo-distribution approach on the lattice
• First Extraction of Transverse Momentum Dependent Helicity Distributions
• $\Delta I=3/2$ and $\Delta I=1/2$ channels of $K\to \pi \pi$ decay at the physical point with periodic boundary conditions
• Accessing gluon polarization with high-$P_T$ hadrons in SIDIS
• Mapping Parton Distributions of Hadrons with Lattice QCD
• Polarized and unpolarized gluon PDFs: generative machine learning applications for lattice QCD matrix elements at short distance and large momentum
• Generalized Parton Distributions from Lattice QCD with Asymmetric Momentum Transfer: Unpolarized Quarks at Nonzero Skewness
• Large-Momentum Effective Theory's Asymptotic Extrapolation vs the Inverse Problem
• A Unified Neural-Network Framework for Nucleon Imaging from Numerical Simulations of QCD