Particle and Astroparticle Physics Seminar

Magnetic field determination to 70 ppb in the new muon g-2 experiment at Fermilab

Joseph Grange

Argonne National Laboratory

While the Standard Model of particle physics has been enormously successful in describing the breadth of both modern and historical experiments, there are many open questions regarding its fundamental efficacy. Precision experiments of intrinsic quantities such as a particle's magnetic moment afford an opportunity to test the completeness of the Standard Model prediction and offer complementary sensitivity to that afforded by particle collider experiments. The measurement of the muon's anomalous magnetic moment at Brookhaven National Laboratory found an intriguing discrepancy of more than three standard deviations with the Standard Model prediction. The precision of the measurement was dominated by the collected statistics and so the community immediately began searching for a new home to execute an improved determination. This effort is now being realized at Fermilab, where new muon beamlines are being developed to deliver over 20 times the statistics observed by the Brookhaven experiment. To fully exploit this enormous statistical power, systematic uncertainties in determining the precession of the muon spin vector and the magnetic field in the storage ring must also be significantly improved. The latter topic is the focus of this presentation.