Lattice Calculations of Nucleon Electromagnetic Form Factors at Large Momentum Transfer

Abstract

In this work, we report a novel technique in lattice QCD for studying the high momentumtransfer region of nucleon form factors. These calculations could give important theoretical input to experiments, such as those of JLab's 12-GeV program and studies of nucleon deformation. There is an extensive history of form-factor calculations on the lattice, primarily with ground states for both the initial and final state. However, determining form factors at large momentum transfer (Q 2 ) has been difficult due to large statistical and systematic errors in this regime. We study the nucleon form factors using three pion masses with both quenched and 2+1-flavor anisotropic lattice configurations with Q 2 as large as 6 GeV 2 . These form factors are further processed to obtain transverse charge and magnetization densities across 2-dimensional impact-parameter space. Our approach can be applied to isotropic lattices and lattices with smaller lattice spacing to calculate even larger-Q 2 form factors.

Magnetic form factors of the octet baryons from lattice QCD and chiral extrapolation

“…4. These results are in line with those from other 2 + 1 and 2 + 1 + 1-flavor simulations [26,27,[31][32][33]. We note that the other lattice simulations included here were performed at a range of values of m K .…”

Octet baryon electromagnetic form factors in a relativistic quark model

“…This can be done using a more complete lattice QCD database including the results from Refs. [81][82][83][84][85][86], and also the results of the new generation of nucleon form factor data in the low Q 2 region [80,87,88], which determine G E and G M simultaneously instead of the ratio 6 G E /G M . In this work we have restricted to use the lattice data from Ref.…”

Octet baryon electromagnetic form factors in nuclear medium

“…It can be useful for the nucleon case to compare the lattice QCD data from [88], and our results using the other lattice QCD simulations. There are for instance different data in [92], from the same group, than the data we have used in our calibration. Unfortunately the lattice QCD studies of the nucleon form factors are mainly performed for the nucleon isovector form factors like…”