A review of techniques for measuring the neutron magnetic form factor

Understanding the neutron magnetic form factor (Gⁿ_M) is crucial to mapping nucleon structure. It is valuable in the interpretations of a wide breadth of neutron properties, including marking the neutron's magnetic moment at low four-momentum transfer squared (Q²), and extracting individual up and down quark contributions at high Q². However, unique experimental challenges are present when probing the neutron form factor. Most experimental measurements must address the lack of a free neutron target by using the bound neutrons in a deuterium target, requiring nuclear corrections accounting for the deuterium's structure.



Here, the main methods of measuring Gⁿ_M using polarized and unpolarized electron-nucleon scattering at different accelerators are reviewed, emphasizing their techniques and challenges. Polarized measurements at low Q² values using the transverse asymmetry A_T' in the scattering of an electron by a Helium-3 nucleus are discussed, highlighting MIT-Bates's and Jefferson Lab experiments. Unpolarized measurements from SLAC experiments and recent CLAS data at higher Q² are utilized to review various techniques, including inclusive quasielastic electron-deuterium scattering, coincidence quasielastic electron-neutron cross-section measurements, and anti-coincidence quasielastic electron-deuterium cross-section measurements. Additionally, the extraction of Gⁿ_M is explored using the ratio of quasielastic electron-neutron to quasielastic electron-proton cross-section, highlighting its benefits in reducing systematic uncertainties and enhancing precision. The comparison of these methods to theoretical models showcases the complexities and advancements in understanding Gⁿ_M, laying the foundation for future research in nucleon structure.