GMn Analysis Status from Q² = 4.5 (GeV/c)² Quasi-elastic Electron-Deuterium Scattering at ε = 0.52 and ε = 0.80

In Fall of 2021 at Jefferson Lab, the SBS Collaboration measured the quasi-elastic neutron/proton cross section ratio via d(e,e')p and d(e,e')n scattering events at several kinematic points with the Super Bigbite Spectrometer (SBS). Via the so-called “ratio” method employed to minimize systematic uncertainty, we will extract the neutron magnetic form factor GMn (experiment e12-09-019) from these data for many Q² values. The status of this extraction and analysis will be presented for two such kinematic points at the same Q², but different longitudinal polarizations of the virtual photon, comprising the nTPE (experiment e12-20-010) data set (SBS-8(9), Q² = 4.5 (GeV/c)², ε = 0.80(0.52)). Essential to this analysis is evaluation of the proton and neutron detection efficiency for the SBS hadron arm from the SBS Hadron Calorimeter (HCal) - preliminary evaluation of this efficiency including data/monte-carlo comparisons will also be presented.