Intermediate Energy Physics at Boston University

点击翻译按钮获取中文摘要

Our Intermediate Energy research group at Boston University consists of threefaculty, two postdoctoral fellows, four graduate students, and severalpart-time undergraduate students. In the next three years, we will:1) Continue to work on the Muon g-2 experiment. The muon is likea heavy electron but is unstable and decays like a radioactive nuclearisotope. Because it has both spin and charge, it behaves like a microscopicbar magnet, whose magnetism we measure in our experiment (g-2). Our latestvalue, 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 afterwe analyze all of our data, it will be very exciting since it suggests theexistence of new physics beyond the standard model. We plan two otherexperiments using the same large storage ring magnet which is used forg-2, the measurement of the muon electric dipole moment(EDM) and thedirect measurement of the muon neutrino mass. The EDM is expected intheory to be smaller than we can measure, while indirect measurementsfrom other experiments suggest that the neutrino mass is not zero.2) Measure the muon lifetime, which determines the strength of theweak 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. Anysignificant deviation of the experimental values from theory would implythat there is physics beyond what we already know.