Atomic tests of discrete symmetries at Berkeley

Abstract

Recent and ongoing experiments testing various fundamental discrete symmetries are discussed, including search for parity nonconservation in dysprosium and ytterbium, investigation of possibilities of searches for parity and time-reversal invariance violation in samarium, and a test of permutation properties of photons in a two-photon transition in barium. EUGENE COMMINS AND ATOMIC TESTS OF DISCRETE SYMMETRIES Professor Eugene Commins is a pioneer in a very tough business-testing fundamental symmetries of Nature with table-top atomic physics. A typical experiment of this kind takes anywhere from 8 to 15 years (and in some cases, even longer), which is a time scale not particularly well matched to that of funding agencies, or the time expected for a graduate student to complete his or her thesis. Unfortunately, not many experiments discover something unexpected, or even set limits for "new physics" at a desired level. Nevertheless, when such a result is eventually achieved, it is often of a scientific value that is hard to overestimate. Professor Commins has succeeded in bringing several experiments of this kind to fruition, starting from the first measurement of atomic parity violation in a highly forbidden atomic transition [1, 2, 3], and culminating in the most stringent limit on the P,T-violating dipole moment of the electron (discussed in B. C. Regan's contribution elsewhere in these Proceedings). In this paper, we review some of the recent and ongoing atomic tests of fundamental symmetries carried out at Berkeley by Eugene's colleagues, former students and "grandstudents." Eugene has participated in much of this work either directly, or as an unlimited source of practical advice and theoretical expertise.