MuSun: A Precision Measurement of Nuclear Muon Capture in Deuterium with a Cryogenic Time Projection Chamber

Abstract

The MuSun experiment aims to measure the muon capture rate on deuterium to 1.5\%, allowing for the extraction of a low energy constant required to quantify the axial two body current in the framework of modern effective field theories. Once obtained, this constant calibrates the two nucleon sector, enabling calculations of related astrophysical reactions of interest, including proton-proton fusion, an important input for stellar models, and the neutrino-deuterium breakup reactions required by the Sudbury Neutrino Experiment to quantify the neutrino flux from the sun. MuSun utilizes the lifetime technique -- extracting the capture rate via a comparison of the negatively charged muon disappearance rate in deuterium to the free muon lifetime-- in combination with a novel cryogenic time projection chamber. The full statistics necessary to reach the precision goal have been acquired in two separate data collection periods. This thesis presents the account of the first of these production datasets, from detector development to the final analysis. The construction, commissioning, and performance of the time projection chamber is described, followed by details of the 2014 data collection period. Aspects of software development and several in depth analyses are described. Based on this high-statistics analysis, limits are set on the effect of all sources of systematic error and several correction strategies are developed.