Measurements of the magnetic dipole moments of particles have played an important role in the understanding of the structure of matter. Deviations from the expected characteristics of "point-like" particles appear as so called anomalous moments and are sensed by observation of the precession rates of the spins of such particles in magnetic fields. For protons and neutrons, anomalous magnetic moments are large as is expected for particles built from quarks. But for electrons and muons, the anomaly is tiny and so far is in agreement with theoretical expectations from the Standard Model to an extraordinary degree of precision. I will describe a beautiful new experimental effort to measure g-2 for the muon to a precision of 0.35 ppm. At this level of sensitivity, the muon g-2 factor is sensitive to many Standard Model extensions of current interest. In particular, it is considered to be a very sensitive test of popular SUSY models. The experiment is progressing very well. I will present new results from a recently completed analysis of the 1998 data, and will give the up-to-the-minute version of the 1999 analysis which will be complete very soon. This colloquium will be aimed at a general audience.

ANL Physics Division Colloquium Schedule