Precision Measurement

The Physics Department has a strong tradition in precision physics, highlighted by the seminal work of Nobel Laureate Hans G. Dehmelt and his co-workers. Its faculty, technical capabilities and the synergy with CENPA, a DOE center of excellence, stimulate an environment for challenging state-of-the-art measurements. Our mission is to identify compelling, precision experiments that either determine fundamental quantities or sensitively test the current paradigms in physics, in particular the standard model of particle physics and the theory of gravity. These efforts include:

• Test of parity and time reversal symmetry by studying electric dipole moments. The most sensitive limit on an EDM comes from our 199Hg experiment. Trapped single ion research provides frequency standards and symmetry tests.
• The Precision Muon Physics Group measured the muon lifetime to determine the Fermi Coupling Constant (MuLan), unambiguously determined the proton’s pseudoscalar coupling (MuCap), is measuring muon capture on deuterium, relevant for fundamental astrophysics reactions (MuSun) and prepares a measurement of the muon anomalous magnetic moment (g-2), to clarify the persistent discrepancy between standard model theory and experiment.
• Symmetry tests in weak interactions of nuclei are performed at CENPA, using the most intense source of 6He in the world. They search for tensor currents in weak interactions in an ongoing electron-antineutrino correlation experiment and a planned measurement of the beta decay spectrum.
• The Dark Axion Matter Experiment (ADMX) uses a resonant microwave cavity within in a large superconducting magnet to search for cold dark matter axions in the local galactic dark matter halo.
• Ultra-cold atom experiments study interacting quantum mixtures of atoms and molecules at 100 nanoKelvins. We also develop an atom interferometer using Bose-Einstein condensates to measure the fine structure constant and test the theory of quantum electrodynamics.
• The Eot-Wash Group pioneered a program to search for macroscopic extra dimensions, spin-dependent axion-like forces, and violations of the weak and strong Equivalence Principles making use of sensitive torsion balances.