New empirical fits to the proton electromagnetic form factors

TL;DR

This paper provides new empirical fits to the proton's electromagnetic form factors based on recent high-precision measurements, resolving discrepancies between different experimental techniques and covering a broad Q^2 range.

Contribution

It introduces updated empirical models for proton form factors incorporating recent polarization transfer data, improving the accuracy of form factor descriptions.

Findings

The ratio G_Ep/G_Mp decreases with increasing Q^2.

New fits accurately describe the magnetic form factor up to 30 GeV^2.

Empirical ratio fit valid for 0.1 < Q^2 < 6 GeV^2.

Abstract

Recent measurements of the ratio of the elastic electromagnetic form factors of the proton, G_Ep/G_Mp, using the polarization transfer technique at Jefferson Lab show that this ratio decreases dramatically with increasing Q^2, in contradiction to previous measurements using the Rosenbluth separation technique. Using this new high quality data as a constraint, we have reanalyzed most of the world e-p elastic cross section data. In this paper, we present a new empirical fit to the reanalyzed data for the proton elastic magnetic form factor in the region 0 < Q^2 < 30 GeV^2. As well, we present an empirical fit to the proton electromagnetic form factor ratio, G_Ep/G_Mp, which is valid in the region 0.1 < Q^2 < 6 GeV^2.