Extraction of the isovector magnetic form factor of the nucleon at zero momentum

TL;DR

This paper introduces position space methods that directly extract the nucleon's isovector magnetic form factor at zero momentum transfer without assuming a specific momentum dependence, using lattice QCD data.

Contribution

The paper presents novel position space techniques for directly obtaining the zero-momentum magnetic form factor, avoiding traditional parametrization assumptions.

Findings

Methods successfully applied to one lattice ensemble

Direct extraction at zero momentum demonstrated

Potential for improved accuracy in form factor determination

Abstract

The extraction of the magnetic form factor of the nucleon at zero momentum transfer is usually performed by adopting a parametrization for its momentum dependence and fitting the results obtained at finite momenta. We present position space methods that rely on taking the derivative of relevant correlators to extract directly the magnetic form factor at zero momentum without the need to assume a functional form for its momentum dependence. These methods are explored on one ensemble using $N_f=2+1+1$ Wilson twisted mass fermions.