Intermediate Energy Physics at Boston University

Trustees Of Boston University, Boston

Investigators

Abstract

Our Intermediate Energy research group at Boston University consists of three faculty, two postdoctoral fellows, four graduate students, and several part-time undergraduate students. In the next three years, we will: 1) Continue to work on the Muon g-2 experiment. The muon is like a heavy electron but is unstable and decays like a radioactive nuclear isotope. Because it has both spin and charge, it behaves like a microscopic bar magnet, whose magnetism we measure in our experiment (g-2). Our latest value, based on a small part of our data, disagrees with the Standard Model (a theory which describes the particles in nature and the forces between them) prediction by several times the error. If this disagreement persists after we analyze all of our data, it will be very exciting since it suggests the existence of new physics beyond the standard model. We plan two other experiments using the same large storage ring magnet which is used for g-2, the measurement of the muon electric dipole moment(EDM) and the direct measurement of the muon neutrino mass. The EDM is expected in theory to be smaller than we can measure, while indirect measurements from other experiments suggest that the neutrino mass is not zero. 2) Measure the muon lifetime, which determines the strength of the weak interaction within the standard model. 3) Measure the muon to electron conversion rate to unprecedented accuracy, a process which is forbidden by the Standard Model. All of these measurements directly test the Standard Model. Any significant deviation of the experimental values from theory would imply that there is physics beyond what we already know.