A Measurement of the Anomalous Precession Frequency of the Positive Muon

David Allen Sweigart
The measurement of the anomalous magnetic moment of the muon, a µ ≡ (g µ − 2)/2, has been a historic test of our theoretical understanding of elementary particles and their interactions. At present, the world average is in tension with the value predicted by the Standard Model of particle physics by more than three standard deviations, possibly caused by new physics interactions. To resolve this discrepancy, the Muon g − 2 experiment at Fermi National Accelerator Laboratory aims to measure a µ
more » ... o a record 140 parts per billon using data taken over four years from 2018 to 2021. The experimental method involves trapping a polarized beam of positive muons in a storage ring containing an extremely uniform magnetic field. The difference in the muons' cyclotron and spin-precession frequencies, ω a , is directly proportional to a µ . This dissertation motivates making an improved measurement of a µ ; outlines the experimental method, with a focus on the backend electronics; and details the algorithm used to reconstruct the decay positrons impacting the electromagnetic calorimeters around the ring. Using data taken in 2018, a blinded measurement of ω a to 410 parts per billion is then presented, which will allow a µ to be determined with a precision comparable to that of the world average. BIOGRAPHICAL SKETCH David Allen Sweigart received a Bachelor of Science summa cum laude in physics and in mathematics in 2013 from the University of Maryland, Baltimore County. As an undergraduate student, he researched nonlinear optical materials for photonic applications from 2010 to 2013. In the summers of 2011 and 2012, he became involved in particle physics, working on the ATLAS and IceCube experiments through the
doi:10.7298/q3d2-cv06 fatcat:552nbuafzbg6zjvnwztflio65m