Recoil Polarization Measurements of the Proton Electromagnetic Form Factor Ratio to Q^2 = 8.5 GeV^2

TL;DR

This paper reports new recoil polarization measurements of the proton electromagnetic form factor ratio at high momentum transfers up to 8.5 GeV^2, providing critical data to constrain models of nucleon structure.

Contribution

It extends the range of accurate measurements of the proton form factor ratio by over 50%, offering new experimental data at higher Q^2 values.

Findings

Extended the Q^2 range for form factor ratio measurements

Provided data that challenge existing nucleon structure models

Enhanced understanding of proton electromagnetic properties

Abstract

Among the most fundamental observables of nucleon structure, electromagnetic form factors are a crucial benchmark for modern calculations describing the strong interaction dynamics of the nucleon's quark constituents; indeed, recent proton data have attracted intense theoretical interest. In this letter, we report new measurements of the proton electromagnetic form factor ratio using the recoil polarization method, at momentum transfers Q2=5.2, 6.7, and 8.5 GeV2. By extending the range of Q2 for which GEp is accurately determined by more than 50%, these measurements will provide significant constraints on models of nucleon structure in the non-perturbative regime.