Nucleon electromagnetic form factors from twisted mass lattice QCD

TL;DR

This paper presents lattice QCD calculations of nucleon electromagnetic form factors using twisted mass fermions, analyzing systematic errors and including ensembles with different quark compositions and pion masses.

Contribution

It provides new lattice QCD results for nucleon form factors with simulations including strange and charm quarks, and discusses systematic error mitigation.

Findings

Form factors computed at near-physical pion mass (130 MeV).

Inclusion of strange and charm quarks in the sea affects results.

Systematic errors from excited states and noise are addressed.

Abstract

Results on the electromagnetic form factors of the nucleon using twisted mass fermion configurations are presented. These include a gauge field ensemble simulated with two degenerate light quarks yielding a pion mass of around 130 MeV, as well as two ensembles that include strange and charm quarks in the sea yielding pion masses of 210 MeV and 373 MeV. Details of the methods used and systematic errors are discussed, such as noise reduction techniques and the effect of excited states contamination.