Geant4 simulation studies for the spectrometer, detector, and shielding systems for the MOLLER experiment*

The MOLLER experiment is a flagship experiment that will take advantage of the 12 GeV upgrade of the Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Lab in Virginia, USA. MOLLER will employ parity-violating electron-electron scattering to indirectly search for Physics Beyond the Standard Model at a relatively low energy scale, complementing direct searches at high-energy colliders. An 11 GeV longitudinally polarized electron beam with rapidly flipping helicity will be scattered from a liquid Hydrogen target and the scattered electrons will be propagated through two spectrometers. The relative difference between scattering cross-sections (detector yields) in opposite helicity states will be measured over integrating windows. This difference, also known as the parity-violating asymmetry, will be used to precisely determine the weak charge of the electron to a precision of 2.4% and the electroweak mixing angle, a fundamental parameter of Standard Model. The high-precision measurements will be compared against Standard Model predictions. In this talk, we will discuss the status of Geant4 simulation studies that looked at the expected risk from radiation on the spectrometer magnets, electronics, and experimental hall site boundary as well as the main sources of background at the detectors for MOLLER. These assessements are critical to the safe operation of the experiment from the perspective of both equipment and personnel.