| Abstract: |
The most precisely measured property of an elementary particle is the magnetic moment of the electron, determined to 3 parts in 10^{13} in measurements that probe the lowest quantum levels of a single trapped electron. Perhaps the greatest triumph of the Standard Model of particle physics is a calculation of this moment that agrees with the measurement. With the assumption that the Standard Model is correct, the measurement determines the fine structure constant more precisely than any other method. Positrons are now available for a measurement of the positron magnetic moment at a similar precision to test the CPT Theorem of the Standard Model with leptons. As a baryon CPT test, our ATRAP collaboration has recently measured the antiproton magnetic moment 680 times more precisely than had previously been possible, with large precision increases hoped for as quantum methods are introduced. Finally, our ACME collaboration is probing the electric dipole moment of the electron using a beam of ThO molecules to test the prediction of the Standard Model (that such a moment is too small to measure) versus the prediction of most all extensions to the Standard Model (that the electron electric dipole moment is small but measurable with the experimental sensitivity of the new measurement). |
