MicroBooNE's Search for a Photon-like Low Energy Excess

MicroBooNE is Liquid Argon Time Projection Chamber (LArTPC) which has been taking neutrino data at Fermilab Booster Neutrino Beamline (BNB) since October 2015. One of its primary goals is to investigate the "Low Energy Excess" of neutrino events observed by the MiniBooNE experiment, for which one candidate interpretation is neutrino neutral current (NC) resonant Delta baryon production with subsequent radiative decay. This is a standard model source of low energy single-photon events that has never been observed but if found to have a high rate could be a sizable contribution to the "Low Energy Excess". In MicroBooNE it would be identified with an event signature of one detached photon shower and some number of proton tracks. This talk will describe the analysis developed to search for NC Delta radiative events in MicroBooNE, consisting of a Boosted Decision Tree (BDT) based event selection with enhanced background reduction using a Semantic Segmentation Network (SSNet) to target the dominant NC π⁰ background.