Alignment of the straw tracking detectors for the Fermilab Muon $g-2$ experiment and systematic studies for a muon electric dipole moment measurement

Abstract

The Fermilab Muon g −2 experiment is currently preparing for its fourth datataking period (Run-4). The experiment-wide effort on the analysis of Run-1 data is nearing completion, with the announcement of the first result expected in the coming months. The final goal of the experiment is to determine the muon magnetic anomaly, a µ = g−2 2 , to a precision of 140 ppb. This level of precision will provide indirect evidence of new physics, if the central value agrees with the previously-measured value of a µ . Essential in reducing the systematic uncertainty on a µ , through measurements of the muon beam profile, are the in-vacuum straw tracking detectors. A crucial prerequisite in obtaining accurate distributions of the beam profile is the internal alignment of the tracking detectors, which is described in this thesis. As a result of this position calibration, the tracking efficiency has increased by 3%, while the track quality increased by 4%. This thesis also discusses an additional measurement that will be made using the tracking detectors: a search for an electric dipole moment (EDM) of the muon, through the direct detection of an oscillation in the average vertical angle of the e + from the µ + decay. An observation of a muon EDM would be evidence of new physics and would provide a new source of CP violation in the charged lepton sector. Essential in measuring the EDM, as well as a µ , are accurate and precise estimations of potential non-zero radial and longitudinal magnetic fields, which were estimated using the Run-1 data. In addition, a preliminary analysis using the Run-1 data was undertaken to estimate the available precision for the a µ measurement using the tracking detectors.First and foremost, I would like to express my deepest gratitude to my supervisor, Mark Lancaster, who, through his outstanding leadership, made my PhD journey a truly remarkable experience. Mark, I greatly value all the advice, support, and encouragement that you have given me over the yearsthank you! A special recognition should be given to Rebecca Chislett, Joe Price, and James Mott. I am truly grateful for the help that you have provided in tackling many of the arising challenges in this thesis, and for investing your time in me. Your ability to solve difficult tasks with ease and a friendly approach serves as an inspiration to me.Nicholas Kinnaird and Saskia Charity, I appreciate your time in answering many of my questions on tracking and data analysis, especially when you were busy finishing your own theses. You both have set a tremendous example for me to follow. I would like to thank the members of the g−2 tracker group: Brendan Casey, Tammy Walton, Alessandra Luca, and others, for creating a fantastic environment to collaborate and share ideas. Past and present members of the UCL g − 2 team have also provided ample support and inspiration to