Event Simulation and Reconstruction for the nEXO Neutrinoless Double Beta Decay Experiment

The nEXO experiment plans to search for neutrinoless double-beta decay (0νββ) half-life in ¹³⁶Xe with a sensitivity > 10²⁸ yr using a time projection chamber (TPC) and 5000 kg of isotopically-enriched liquid xenon.  The credibility of the sensitivity estimate hinges on detailed simulations of the physics and detector response, validated input parameters, and realistic algorithms for event reconstruction. All steps of nEXO’s simulation and reconstruction have been recently improved, including the GEANT4 geometry, the event interaction in the liquid xenon, the transport of the ionization electrons and scintillation photons, up to the signals generation and the algorithms that process these to extract the high-level quantities for the 0νββ analysis. In this talk, I will review these developments, present the resulting detector performance, and connect them to the experiment’s sensitivity reach.