Charge Symmetry Violation in the Electromagnetic Form Factors of the Proton

TL;DR

This paper reports the first lattice QCD-based extraction showing extremely small charge symmetry violation in proton electromagnetic form factors, significantly below current experimental bounds, thus enabling more precise future tests of QCD predictions.

Contribution

It provides the first lattice QCD analysis quantifying charge symmetry violation in proton electromagnetic form factors, revealing it to be much smaller than previously constrained.

Findings

Charge symmetry violation in proton form factors is an order of magnitude smaller than current bounds.

Results suggest minimal impact of CSV on proton strangeness measurements.

Findings support the potential for more precise experimental tests of QCD predictions.

Abstract

Experimental tests of QCD through its predictions for the strange-quark content of the proton have been drastically restricted by our lack of knowledge of the violation of charge symmetry (CSV). We find unexpectedly tiny CSV in the proton's electromagnetic form factors by performing the first extraction of these quantities based on an analysis of lattice QCD data. The resulting values are an order of magnitude smaller than current bounds on proton strangeness from parity violating electron-proton scattering experiments. This result paves the way for a new generation of experimental measurements of the proton's strange form factors to challenge the predictions of QCD.