Strange Form Factor(sFF)

The Strange Form Factor (sFF) experiment will precisely determine the contribution of strange quarks to its electromagnetic form factor. This measurement is essential for disentangling the individual quark contributions, known as flavor decomposition. Recent theoretical breakthroughs in lattice QCD and phenomenological models strongly suggest that significant discoveries can be made by probing the proton at a specific momentum transfer. Therefore, the experiment will measure the precise parity-violating asymmetry in electron-proton scattering at a $Q^2$=2.5 (GeV/c)${}^2$. This will be achieved by directing a highly polarized electron beam (6.6 GeV, 65 $\mu$A, 85% polarization) onto a 10-cm liquid hydrogen target within the experimental hall. Specialized detectors, including a PbWO$_4$ electron calorimeter and an iron-scintillator proton calorimeter, will be constructed to detect the scattered particles. The experiment is designed to achieve a statistical precision of $\pm$6.2 parts per million in the parity-violating asymmetry measurement, enabling a sensitive exploration of the proton’s inner workings.

The construction of a prototype detector is currently underway to validate the experiment’s design and feasibility. This process involves several key tasks. A test stand is being designed to house and evaluate the detector prototype. To accurately predict and understand the detector’s performance within the experimental setup and the test stand, detailed Geant4 simulations needs to be done. These simulations provide critical insights into the design of detector and detector responses, allowing for optimization and refinement. A significant amount of work is required to construct the test stand. This includes the assembly of the calorimeters, the installation of trigger scintillator assemblies, and the testing of the prototype in the test lab.