Detection system for electron-proton coincidences in neutron decay

By precisely measuring angular correlations in neutron decay, we can perform precise tests of the Standard Model and search for new physics beyond the Standard Model. The upcoming Nab and UCNB experiments will measure the correlations $a$ and $b$, and $B$, respectively, in neutron decay. The collaborations have jointly developed a prototype detection system based on thick, large area silicon detectors which meets experimental requirements of $\sim$3~keV FWHM energy resolution, rise times of $\sim$50~ns, and energy thresholds below 10~keV. We will present results of characterization of the prototype and an update on the development of the final, fully instrumented detection system. We also present a study of very thin deadlayer silicon drift detectors in development by the TRISTAN collaboration, and their possible applicability to neutron decay correlation experiments.​