Probing Nab's proton time-of-flight reconstruction accuracy through detailed pulse shape simulation

Precise measurements of neutron beta decay observables are one of the most promising avenues for testing the electroweak Standard Model at the TeV scale. In particular, a more precise determination of the vector to axial vector admixture in neutron beta decay will shed light on the current tension in the Cabibbo-Kobayashi-Maskawa matrix top-row unitarity requirement without any of the nuclear structure corrections that limit the current global average. The Nab experiment at the Spallation Neutron Source at Oak Ridge National Lab will measure the beta-antineutrino angular correlation following neutron decay inside a hermetic, magnetic spectrometer with an anticipated relative precision of approximately 0.1%. An event-by-event angular reconstruction occurs via a time-of-flight measurement of the outgoing proton, which requires excellent control on timing distortions due to field transport and detector effects. We will present an overview of sophisticated pulse shape simulation efforts, and highlight results of detailed plasma effects and entrance window studies.