Assylbekov, Shamil M., authorWilson, Robert J., advisorToki, Walter, committee memberHarton, John, committee memberBerger, Bruce, committee memberHulpke, Alexander, committee member2015-08-282015-08-282015http://hdl.handle.net/10217/167110T2K is an international collaboration that has constructed an experiment in Japan to investigate the properties of the neutrino. It consists of two near detectors, ND280 and INGRID, and a far detector - Super-Kamiokande. ND280 has multiple sub-detectors with the π⁰ detector (PØD) being of most importance to this analysis. This work describes the first measurement of neutrino cross section for charged-current single positively charged pion (CC1π⁺) interaction channel on water (H₂O) using the PØD as target and detector. The PØD detector has been taking neutrino interaction data since 2009 in configurations with and without an integrated water target. Using a statistical water-in/water-out event rate subtraction, a measurement of the νμ-induced CC1π⁺ cross section on water is reported to be ‹σ› = 1.10 x 10⁻³⁹ +0.39·10⁻³⁹/-0.36·10⁻³⁹ cm², where the result is provided in the form of a single-bin cross section integrated over the entire T2K neutrino energy range. The measurement is based on a sample of 2,703 events selected from beam runs of $2.64 x 10²⁰ protons-on-target (POT) with the PØD water-in configuration, and 2,187 events selected from $3.71 x 10²⁰ POT with the water-out configuration. The corresponding Monte Carlo simulation predicted numbers of background events to be 1,387.2 and 1,046.0 for the water-in and water-out detector configurations, respectively. The accuracy of the result is dominated by flux and cross section models uncertainties. The data favors a systematically smaller cross section when compared to the model but within the uncertainties it is consistent with the Monte Carlo simulation prediction of $1.26 x 10⁻³⁹cm². The result, its significance, and the strategy for future CC1π⁺ measurements are discussed in conclusion.born digitaldoctoral dissertationsengCopyright and other restrictions may apply. User is responsible for compliance with all applicable laws. For information about copyright law, please see https://libguides.colostate.edu/copyright.cross-sectionpionT2Kneutrinocharged-currentproductionText