Strange magnetic form factor of the proton at $Q^2 = 0.23$ GeV$^2$

TL;DR

This paper calculates the strange magnetic form factor of the proton at a specific momentum transfer using lattice QCD data, chiral corrections, and experimental inputs, providing a precise estimate of $G_M^s$.

Contribution

It introduces a method combining quenched lattice data, chiral perturbation theory, and experimental results to determine the strange magnetic form factor at finite $Q^2$.

Findings

Estimated $G_M^s$ at $Q^2=0.23$ GeV$^2$ as -0.034 ± 0.021 μ_N.

Applied chiral corrections to lattice data for quark contributions.

Used charge symmetry and experimental magnetic form factors for analysis.

Abstract

We determine the $u$ and $d$ quark contributions to the proton magnetic form factor at finite momentum transfer by applying chiral corrections to quenched lattice data. Heavy baryon chiral perturbation theory is applied at next to leading order in the quenched, and full QCD cases for the valence sector using finite range regularization. Under the assumption of charge symmetry these values can be combined with the experimental values of the proton and neutron magnetic form factors to deduce a relatively accurate value for the strange magnetic form factor at $Q^2=0.23$ GeV$^2$, namely $G_M^s=-0.034 \pm 0.021$ $\mu_N$.