Precision Nucleon Charges and Form Factors Using 2+1-flavor Lattice QCD

Abstract

We present high statistics results for the isovector nucleon charges and form factors using seven ensembles of 2+1-flavor Wilson-clover fermions. The axial and pseudoscalar form factors obtained on each ensemble satisfy the PCAC relation once the lowest energy $N\pi$ excited state is included in the spectral decomposition of the correlation functions used for extracting the ground state matrix elements. Similarly, we find evidence that the $N\pi \pi$ excited state contributes to the correlation functions with the vector current, consistent with the vector meson dominance model. The resulting form factors are consistent with the Kelly parameterization of the experimental electric and magnetic data. Our final estimates for the isovector charges are $g_A^{u-d}=1.31(06)(05{)}_{sys}$, $g_S^{u-d}=1.06(10)(06{)}_{sys}$, and $g_T^{u-d}=0.95(05)(02{)}_{sys}$, where the first error is the overall analysis uncertainty and the second is an additional combined systematic uncertainty. The form factors yield: (i) the axial charge radius squared, ${⟨r_A^2⟩}^{u-d}=0.428(53)(30{)}_{sys}{\mathrm{fm}}^2$, (ii) the induced pseudoscalar charge, $g_P^{\ast }=7.9(7)(9{)}_{sys}$, (iii) the pion-nucleon coupling $g_{\pi \mathrm{NN}}=12.4(1.2)$, (iv) the electric charge radius squared, ${⟨r_E^2⟩}^{u-d}=0.85(12)(19{)}_{sys}{\mathrm{fm}}^2$, (v) the magnetic charge radius squared, ${⟨r_M^2⟩}^{u-d}=0.71(19)(23{)}_{\mathrm{sys}}{\mathrm{fm}}^2$, and (vi) the magnetic moment ${\mu }^{u-d}=4.15(22)(10{)}_{\mathrm{sys}}$. All our results are consistent with phenomenological/experimental values but with larger errors. Lastly, we present a Padé parameterization of the axial, electric and magnetic form factors over the range $0.04<Q^2<1$ GeV${}^2$ for phenomenological studies.

arXiv comment84 pages, 39 figures, 24 tables. This is the version published by PRD

References in corpus (68)

• Quantum Monte Carlo methods for nuclear physics
• The Chroma Software System for Lattice QCD
• FLAG Review 2019
• A General Method for Non-Perturbative Renormalization of Lattice Operators
• Solving Lattice QCD systems of equations using mixed precision solvers on GPUs
• Axial structure of the nucleon
• Hyper-Kamiokande Design Report
• First Measurement of the Muon Neutrino Charged Current Quasielastic Double Differential Cross Section
• High-precision scale setting in lattice QCD
• Excited state baryon spectroscopy from lattice QCD
• Simulation of QCD with N_f=2+1 flavors of non-perturbatively improved Wilson fermions
• Lattice QCD ensembles with four flavors of highly improved staggered quarks
• Probing Novel Scalar and Tensor Interactions from (Ultra)Cold Neutrons to the LHC
• Nucleon structure from mixed action calculations using 2+1 flavors of asqtad sea and domain wall valence fermions
• Effective noise reduction techniques for disconnected loops in Lattice QCD
• A new class of variance reduction techniques using lattice symmetries
• Low energy analysis of the nucleon electromagnetic form factors
• A percent-level determination of the nucleon axial coupling from Quantum Chromodynamics
• Measurement of the Weak Axial-Vector Coupling Constant in the Decay of Free Neutrons Using a Pulsed Cold Neutron Beam
• Renormalization of quark bilinear operators in a momentum-subtraction scheme with a nonexceptional subtraction point
• Deuterium target data for precision neutrino-nucleus cross sections
• Model independent extraction of the proton charge radius from electron scattering
• The form factors of the nucleon at small momentum transfer
• Adaptive multigrid algorithm for the lattice Wilson-Dirac operator
• Determination of the Weak Axial Vector Coupling from a Measurement of the Beta-Asymmetry Parameter A in Neutron Beta Decay
• Isovector Charges of the Nucleon from 2+1+1-flavor Lattice QCD
• Precision calculation of threshold pi^- d scattering, pi N scattering lengths, and the GMO sum rule
• Nucleon electromagnetic form factors on the lattice and in chiral effective field theory
• Axial Vector Form Factors of the Nucleon from Lattice QCD
• Model independent determination of the axial mass parameter in quasielastic neutrino-nucleon scattering
• Proton and neutron electromagnetic form factors from lattice QCD
• Quantum Monte Carlo Methods in Nuclear Physics: Recent Advances
• Axial Vector Form Factors from Lattice QCD that Satisfy the PCAC Relation
• Nucleon axial, tensor and scalar charges and $\sigma$-terms in lattice QCD
• Quark spins and Anomalous Ward Identity
• Nucleon charges with dynamical overlap fermions
• Nucleon Masses and Magnetic Moments in a Finite Volume
• Axial, induced pseudoscalar, and pion-nucleon form factors in manifestly Lorentz-invariant chiral perturbation theory
• Precision Measurement of the Neutron Beta-Decay Asymmetry
• New result for the neutron $\beta$-asymmetry parameter $A_0$ from UCNA
• On the pi pi continuum in the nucleon form factors and the proton radius puzzle
• Adaptive Multigrid Algorithm for Lattice QCD
• Nucleon axial structure from lattice QCD
• Nucleon form factors on a large volume lattice near the physical point in 2+1 flavor QCD
• Nucleon axial and pseudoscalar form factors from lattice QCD at the physical point
• Nucleon isovector charges and twist-2 matrix elements with $N_f=2+1$ dynamical Wilson quarks
• Measurement of Muon Capture on the Proton to 1% Precision and Determination of the Pseudoscalar Coupling g_P
• Nucleon axial, scalar, and tensor charges using lattice QCD at the physical pion mass
• Nucleon Electromagnetic Form Factors in the Continuum Limit from 2+1+1-flavor Lattice QCD
• Computing the nucleon charge and axial radii directly at $Q^2=0$ in lattice QCD
• Lattice QCD and Neutrino-Nucleus Scattering
• Isovector charges of the nucleon from 2+1-flavor QCD with clover fermions
• Controlling Excited-State Contamination in Nucleon Matrix Elements
• $N\pi$-state contamination in lattice calculations of the nucleon axial form factors
• Precision determination of pion-nucleon coupling constants using effective field theory
• Isovector electromagnetic form factors of the nucleon from lattice QCD and the proton radius puzzle
• The pion-nucleon sigma term from lattice QCD
• Precise Determination of Charge Dependent Pion-Nucleon-Nucleon Coupling Constants
• Nucleons Properties at Finite Lattice Spacing in Chiral Perturbation Theory
• Nucleon-pion-state contribution in lattice calculations of the nucleon charges $g_A,g_T$ and $g_S$
• Nucleon matrix elements using the variational method in lattice QCD
• $N\pi$-state contamination in lattice calculations of the nucleon pseudoscalar form factor
• Measurement of the Formation Rate of Muonic Hydrogen Molecules
• On the effect of excited states in lattice calculations of the nucleon axial charge
• Lattice QCD Determination of $g_A$
• Nucleon mass and isovector couplings in 2+1-flavor dynamical domain-wall lattice QCD near physical mass
• Three-particle $N\pi \pi$ state contribution to the nucleon two-point function in lattice QCD
• Nucleon Momentum Fraction, Helicity and Transversity from 2+1-flavor Lattice QCD

Cited by in corpus (29)

• 50 Years of Quantum Chromodynamics
• Gravitational form factors of the proton from lattice QCD
• FLAG Review 2024
• Event Generators for High-Energy Physics Experiments
• The Present and Future of QCD
• Status of Lattice QCD Determination of Nucleon Form Factors and their Relevance for the Few-GeV Neutrino Program
• The proton radius (puzzle?) and its relatives
• First moments of the nucleon transverse quark spin densities using lattice QCD
• Octet baryon isovector charges from $N_f=2+1$ lattice QCD
• Transversity distributions and tensor charges of the nucleon: extraction from dihadron production and their universal nature
• First simultaneous global QCD analysis of dihadron fragmentation functions and transversity parton distribution functions
• Nucleon relativistic polarization and magnetization distributions
• Toward $N$ to $N\pi$ matrix elements from lattice QCD
• Nucleon isovector couplings in Nf = 2 + 1 lattice QCD at the physical point
• Theoretical tools for neutrino scattering: interplay between lattice QCD, EFTs, nuclear physics, phenomenology, and neutrino event generators
• Detailed analysis of excited state systematics in a lattice QCD calculation of $g_A$
• Axial-vector exchange contribution to the Hyperfine Splitting
• Light-quark mass dependence of the nucleon axial charge and pion-nucleon scattering phenomenology
• QCD Analysis of $\Delta S=0$ Hadronic Parity Violation
• Towards a unified treatment of $\Delta S=0$ parity violation in low-energy nuclear processes
• Method for high-precision determination of the nucleon axial structure using lattice QCD: Removing $\pi N$-state contamination
• Energy-momentum tensor form factor D(t) of proton and neutron
• Improved superscaling description of electron and charged-current neutrino quasielastic scattering using effective mass dynamics
• Towards a Unified Model of Neutrino-Nucleus Interactions
• Self-consistent optimization of the $z$-Expansion for $B$ meson decays
• Nucleon axial-vector form factor and radius from future neutrino experiments
• Single pion-production and pion propagation in Achilles
• Quasielastic Lepton-Nucleus Scattering and the Correlated Fermi Gas Model
• Exploring Nucleon Structure and the Proton Mass Problem through Holographic QCD