Nucleon and Pion Form Factors from $N_f=2+1$ Anisotropic Lattices

Abstract

We report a recent lattice-QCD calculation of nucleon and pion electromagnetic form factors and nucleon axial form factors, with special emphasis on large $Q^2$. Conventional lattice form-factor calculations can only reach about 2.5 GeV${}^2$, but in this work the transfer momentum is pushed as large as 6 GeV${}^2$. Here, we demonstrate the results on 2+1-flavor anisotropic clover lattices for the nucleon and pion, comparing with low-$Q^2$ quantities, such as Dirac and Pauli radii, anomalous magnetic moments, $g_A$ and $M_A$. Our approach can be applied to isotropic lattices and lattices with smaller lattice spacing to achieve even larger-$Q^2$ form factors. The form factors are processed to obtain transverse charge and magnetization densities across 2-dimensional impact-parameter space. These measurements could give important theoretical input to experiments, such as those of JLab's 12-GeV program, and provide insight into hadronic structure.

arXiv comment13 pages, 8 figures

References in corpus (2)

• Nucleon axial charge in 2+1 flavor dynamical lattice QCD with domain wall fermions
• The Pion Form Factor at Large Momentum Transfer

Cited by in corpus (3)

• Probing Novel Scalar and Tensor Interactions from (Ultra)Cold Neutrons to the LHC
• Nucleon isovector couplings from $N_f=2$ lattice QCD
• Lattice QCD for Precision Nucleon Matrix Elements