Measurement of K+ Production in νμ Charged-Current Interactions on Liquid Argon with MicroBooNE and Enhancing Proton Decay Sensitivity at DUNE

Abstract

The Standard Model (SM) of particle physics successfully describes most elementary particle phenomena but fails to explain several key observations including non-zero neutrino masses, matter–antimatter asymmetry, or dark matter. Studies of neutrino oscillations and proton decay offer pathways to searching for physics beyond the SM. The Deep Underground Neutrino Experiment (DUNE), utilising liquid argon time projection chamber (LArTPC) technology, aims to address these questions but requires precise measurements and modelling of neutrino interactions and background processes to optimise its sensitivity. Currently, data on charged-current muon-neutrino-induced K⁺ production on liquid argon are limited to a single statistically constrained measurement. This thesis presents the first measurement of this interaction using the Neutrinos at the Main Injector (NuMI) beam at the Micro Booster Neutrino Experiment (MicroBooNE) LArTPC. The NuMI beam provides a dataset with a neutrino flux and energy distribution distinct from the previously measured beam, crucial for validating and refining simulation models. Given that K⁺ production is a significant background in proton decay searches at DUNE, improving the understanding of this interaction is essential. A rigorous event selection strategy was implemented to suppress background events, and a specialised reconstruction algorithm was designed to enhance the identification of K+ decays. Furthermore, a dedicated reconstruction algorithm was developed for proton decay via the channel p→νK⁺ with the DUNE detector. This algorithm significantly enhances kaon decay identification, thereby increasing the sensitivity to potential proton decay events, advancing neutrino interaction studies, searches beyond the SM.