$N\pi$-state contamination in lattice calculations of the nucleon electromagnetic form factors

Abstract

The nucleon-pion-state contribution to QCD two-point and three-point functions relevant for lattice calculations of the nucleon electromagnetic form factors are studied in chiral perturbation theory. To leading order the results depend on a few experimentally known low-energy constants only, and the nucleon-pion-state contribution to the form factors can be estimated. The nucleon-pion-state contribution to the electric form factor $G_{\mathrm{E}}(Q^2)$ is at the +5 percent level for a source-sink separation of 2 fm, and it increases with increasing momentum transfer $Q^2$. For the magnetic form factor the nucleon-pion-state contribution leads to an underestimation of $G_{\mathrm{M}}(Q^2)$ by about 5 percent that decreases with increasing $Q^2$. For smaller source-sink separations that are accessible in present-day lattice simulations the impact is larger, although the ChPT results may not be applicable for such small time separations. Still, a comparison with lattice data at $t\approx 1.6$ fm works reasonably well.

arXiv comment33 pages, 11 figures

References in corpus (33)

• Model independent extraction of the proton charge radius from electron scattering
• Isovector Charges of the Nucleon from 2+1+1-flavor Lattice QCD
• The nucleon axial charge from lattice QCD with controlled errors
• Axial Vector Form Factors of the Nucleon from Lattice QCD
• Proton and neutron electromagnetic form factors from lattice QCD
• Axial Vector Form Factors from Lattice QCD that Satisfy the PCAC Relation
• Nucleon axial form factors using lattice QCD simulations with a physical value of the pion mass
• Nucleon axial structure from lattice QCD
• Iso-vector axial form factors of the nucleon in two-flavour lattice QCD
• Nucleon form factors on a large volume lattice near the physical point in 2+1 flavor QCD
• Nucleon electromagnetic form factors in two-flavour QCD
• Chiral perturbation theory for gradient flow observables
• Domain decomposition, multi-level integration and exponential noise reduction in lattice QCD
• 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
• $N\pi$-state contamination in lattice calculations of the nucleon axial form factors
• A local factorization of the fermion determinant in lattice QCD
• Isovector electromagnetic form factors of the nucleon from lattice QCD and the proton radius puzzle
• Solving the PCAC puzzle for nucleon axial and pseudoscalar form factors
• Nucleon-pion-state contribution in lattice calculations of the nucleon charges $g_A,g_T$ and $g_S$
• Nucleon-pion-state contribution to nucleon two-point correlation functions
• $N\pi$-state contamination in lattice calculations of the nucleon pseudoscalar form factor
• Time Dependence of Nucleon Correlation Functions in Chiral Perturbation Theory
• Chiral Corrections to Nucleon Two- and Three-Point Correlation Functions
• Chiral perturbation theory and nucleon-pion-state contaminations in lattice QCD
• Chiral extrapolation of nucleon wave function normalization constants
• Excited-state contribution to the axial-vector and pseudo-scalar correlators with two extra pions
• Multi-hadron-state contamination in nucleon observables from chiral perturbation theory
• $N\pi$-states and the projection method for the nucleon axial and pseudoscalar form factors
• Opposite-Parity Contaminations in Lattice Nucleon Form Factors
• Excited states in nucleon structure calculations
• Nucleon-pion-state contribution in lattice calculations of moments of parton distribution functions
• Three-particle $N\pi \pi$ state contribution to the nucleon two-point function in lattice QCD

Cited by in corpus (5)

• The pion-nucleon sigma term from lattice QCD
• Nucleon relativistic polarization and magnetization distributions
• Investigation of pion-nucleon contributions to nucleon matrix elements
• Application of Laplace filters to the analysis of lattice time correlators
• Proton and neutron electromagnetic form factors from lattice QCD in the continuum limit