Model independent results for nucleon structure

TL;DR

This paper reviews recent model-independent experimental results on the internal charge and magnetization densities of nucleons, revealing their shapes and how these can be measured through transverse momentum distributions.

Contribution

It presents new model-independent insights into nucleon structure, including charge and magnetization densities, and discusses measurement techniques for spin-dependent densities.

Findings

Proton shape is not round.

Model-independent charge and magnetization densities are established.

Spin-dependent densities can be measured via transverse momentum distributions.

Abstract

I review recent results regarding the nucleon charge and magnetization densities as well as the shape of the nucleon. First, some phenomenolgical considerations that show that the shape of the proton is not round are discussed. Then model independent results regarding the neutron and proton charge density, and the proton magnetization density are presented. Finally, I show how the spin-dependent densities that reveal the shape of the proton can be measured via their relation with transverse momentum distributions. The present work is made possible by the recent tremendous experimental progress made at Bates, Mainz and Jefferson Laboratory.