Accessing hadronic form factors at large momentum transfers has traditionally presented a challenge for lattice QCD simulations. Here we demonstrate how a novel implementation of the Feynman-Hellmann method can be employed to calculate hadronic form factors in lattice QCD at momenta much higher than previously accessible. Our simulations are performed on a single set of gauge configurations with three flavours of degenerate mass quarks corresponding to mπ≈470 MeV. We are able to determine the electromagnetic form factors of the pion and nucleon up to approximately 6 GeV2, with results for GE/GM in the proton agreeing well with experimental results.
@article{arxiv.1702.01513,
title = {Electromagnetic form factors at large momenta from lattice QCD},
author = {A. J. Chambers and J. Dragos and R. Horsley and Y. Nakamura and H. Perlt and D. Pleiter and P. E. L. Rakow and G. Schierholz and A. Schiller and K. Somfleth and H. Stüben and R. D. Young and J. Zanotti},
journal= {arXiv preprint arXiv:1702.01513},
year = {2018}
}