Determination and Simulation of Kinematic Parameters in the Qweak Experiment

The Qweak Experiment aims to measure the weak charge of the proton. In order to obtain the required level of precision in the final result, we must calculate corrections to the momentum transfer, Q, in the scattering event. We simulate the experiment in GEANT4 and compare the simulations to the experimental data. In my project, I was responsible for creating comparison plots for Q, the scattering angle, θ, and the scattered energy, E. We found that E had some major discrepancies between experiment and simulation. After verifying that the simulations were implementing energy loss processes properly, we found that E shows an octant-dependence consistent with a tilt to the rotator holding the vertical drift chambers.