Gerald Gabrielse
Harvard University
One electron, suspended by itself and cooled to the ground state of its cyclotron motion in a magnetic field, is used to measure the electron magnetic moment about 15 times more accurately than any previous measurement -- to 3 parts in 10^{13}. The fine structure constant is determined more than an order of magnitude more accurately by this measurement, along with QED theory, than by any other method. One positron should soon be available so that the electron and positron moments can be compared at the new level of precision to make the most stringent test of CPT invariance with a lepton system. Hundreds of millions of positron, along with millions of antiprotons, are now being used to make antihydrogen atoms which eventually will be used for precise spectroscopic comparisons of antihydrogen and hydrogen atoms. A new measurement with ThO molecules seeks to determine the electric dipole moment of the electron to test and constrain proposed extensions to the standard model of particle physics.
Friday, November 13, 2009 at 4:00 PM
Room L211, Technological Institute
Refreshments are served at 3:30 PM
