Nuclear Physics Seminars

The Super BigBite Spectrometer (SBS) physics program at Jefferson Lab provides a large acceptance apparatus to precisely measure the proton and neutron form factors. The neutron electromagnetic form factors, \(G_E^n\) and \(G_M^n\), give important insights into the nucleon structure. The GMn experiment took place in fall of 2021, measuring \(G_M^n\) by colliding electrons on a liquid deuterium target, and extended the \(Q^2\) coverage from 5.0 to 13.6 GeV\(^2\). The GEn-II experiment will take place in August 2022, measuring \(G_E^n\) by colliding a polarized electron beam with a polarized \(^3\)He target, will extend the \(Q^2\) coverage from 3.5 to 10.2 GeV\(^2\). In both experiments Gas Electron Multiplier (GEM) based trackers will precisely measure the scattered electrons. GEM detectors are capable of rates higher than 500 kHz/cm\(^2\) with position resolutions of 70 \(\mu\)m. The proper running of these detectors is critical to the success of the SBS experiments. At our highest \(Q^2\) point we expect to be able to calculate the form factor ratio with an accuracy better than \(\Delta (G_E^n/G_M^n) = 0.20\), which corresponds to \(\Delta G_E^n = 3 \times 10^{-4}\) with accurate measurements of \(G_M^n\). This would greatly increase our understanding of the neutron in a region where no data is available.