Precision Measurements of Nucleon Structure - The JLab SBS Program: Past, Present, and Future

Electron scattering is one of the simplest and most productive probes of the internal structure of the nucleon. Precise measurements of the elastic form factors reveal details about the nucleon's internal structure and provide inputs for a range of theoretical models. Since 2021, SBS experiments at Jefferson Lab have measured the elastic form factors of the proton and neutron using elastic and quasi-elastic electron scattering on Hydrogen, Deuterium, and Helium-3. The SBS experiments will produce measurements of the form factors with unprecedented precision at a variety of four-momentum transfers (Q²) including at Q² significantly higher than previous experiments. These experiments have leveraged the capabilities of the increased electron energy from the Continuous Electron Beam Accelerator Facility, and are the first measurements of the nucleon form factors GMn, GEn, and GEp in the 12 GeV era at Jefferson Lab. The measurements of GMn and GEn extend the Q² range by a factor of 3. The measurement of GEp will increase the Q² coverage using the polarization transfer method to ≈ 12 GeV² with significantly improved precision compared to measurements made with the Rosenbluth method. The SBS program also aims to make future measurements of single-spin asymmetries using semi-inclusive deep inelastic scattering, parity violating asymmetries in electron-proton scattering and other proposed methods. An overview of completed, ongoing, and future SBS experiments showcasing the capabilities of open detectors to operate in extremely high luminosity environments will be discussed.