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

2011/04/21 by Lin, Huey-Wen, Cohen, Saul D.
#FOS: Physical sciences #High Energy Physics - Lattice (hep-lat)

paper · doi:10.48550/arxiv.1104.4319

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 Q². Conventional lattice form-factor calculations can only reach about 2.5 GeV², but in this work the transfer momentum is pushed as large as 6 GeV². Here, we demonstrate the results on 2+1-flavor anisotropic clover lattices for the nucleon and pion, comparing with low-Q² 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-Q² 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.

Related

• Lattice Calculations of Nucleon Electromagnetic Form Factors at Large Momentum Transfer
• Nucleon electromagnetic form factors at high Q² from Wilson-clover fermions
• Nucleon form factors from N_f=2+1+1 twisted mass QCD at the physical point
• Nucleon form factors in N_f=2+1 lattice QCD at the physical point : finite lattice spacing effect on the root-mean-square radii
• Nucleon Form Factors from the Feynman-Hellmann Method in Lattice QCD