Analysis of the UCNtau Neutron Lifetime over the 2019-2022 datasets

There is a large discrepancy between the neutron lifetimes measured using the bottle method and the beam method; the discrepancy is ~10 seconds with an unresolved puzzle of why the lifetime of neutrons are longer in the beam method compared to the bottle method. The UCNtau experiment uses the bottle method to measure the neutrons in a magneto-gravitational trap. The yield and lifetime of the trapped neutrons are measured by observing that the neutron population decreases with time following the general exponential equation: Yeilds = et1-t2tau(1). The goal here is to extract a consistent neutron lifetime from runs with varying source output and detector geometries from the UCNtau experiment from 2019-2022. Counts from various neutron monitors are crucial to lifetime analysis, including the old gatevalve monitor and roundhouse monitor, which monitors how many initial neutrons are entering our system, and the dagger coincidence count which measure how many neutrons have entered our system after a prescribed holding time. We analyze the lifetimes by comparing a global analysis function to a pair analysis function. The global analysis analyzes all of the neutron coincidence counts and fits to a single lifetime function that will generate a single neutron lifetime. The other method of pair analysis uses a pair of adjacent runs of two different hold times, by using the exponential decay function, to extract many lifetime values from repeated measurements. Time-varying background also needs to be tracked and removed.