Presented By: Department Colloquia
Department Colloquium | The Final Fermilab muon g-2 result
Tim Chupp (U-M Physics)
The muon magnetic moment anomaly arises due to quantum interactions of muons and the vacuum, mostly due to quantum electrodynamics (QED), but with contributions from ALL Standard Model interactions as well as Beyond-Standard-Model physics. The Fermilab muon g-2 experiment employed a 50m circumference 1.45 T magnetic storage ring and measured the precession of muons with respect to the momentum of the cyclotron orbits for six years. The precision of the final Fermilab result, 127 ppb, combines statistically limited measurement of the muon precession and measurement of the magnetic field averaged over the muon storage volume employing novel magnetometry and analysis techniques developed at UM. The Standard Model calculation, based on known physics, is confounded by the strong interaction and has incorporated new approaches based on Lattice Gauge Theory. Experiment and theory are currently consistent, though the theory uncertainty has gotten worse while the experimental uncertainty has improved. In this talk I will tell the story of this precision measurement.