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

Abstract

We apply a formalism inspired by heavy-baryon chiral perturbation theory with finite-range regularization to dynamical 2 th 1-flavor CSSM/QCDSF/UKQCD Collaboration lattice QCD simulation results for the electric form factors of the octet baryons. The electric form factor of each octet baryon is extrapolated to the physical pseudoscalar masses, after finite-volume corrections have been applied, at six fixed values of Q² in the range 0.2-1.3 GeV². The extrapolated lattice results accurately reproduce the experimental form factors of the nucleon at the physical point, indicating that omitted disconnected quark loop contributions are small relative to the uncertainties of the calculation. Furthermore, using the results of a recent lattice study of the magnetic form factors, we determine the ratio mu pGp E=Gp M. This quantity decreases with Q² in a way qualitatively consistent with recent experimental results.