Current trends in searches for new physics using measurements of parity violation and electric dipole moments in atoms and molecules

Abstract

We review current status of the study of parity and time invariance phenomena in atoms, nuclei and molecules. We focus on three most promising areas of research: (i) parity non-conservation in a chain of isotopes, (ii) search for nuclear anapole moments, and (iii) search for permanent electric dipole moments (EDM) of atoms and molecules which are caused by either, electron EDM or nuclear T, P -odd moments such as nuclear EDM and nuclear Schiff moment.

The Buffer Gas Beam: An Intense, Cold, and Slow Source for Atoms and Molecules

“…An experimentally feasible approach to using APV to probe electroweak physics was first proposed in 1974, [114] and since then APV has been observed in a number of atoms [29,[115][116][117]. Here we will briefly discuss how buffer gas beams may improve experimental studies of APV; detailed discussions of APV theory and experiments may be found elsewhere [29,30,115,118].…”

“…An experimental signature of an anapole moment is then a difference in parity violating amplitudes between different hyperfine levels. So far only a single anapole moment has been measured, in the 133 Cs nucleus [121], though other experiments are underway [30].…”

“…( 59)) in the parity violating amplitude scales as ∝ N −1/2 T −1 , where N is the total number of interrogated molecules and T is the time that the molecules spend interacting with the electro-magnetic fields. Also similar to the EDM measurements is the choice of molecules, including [30] BiO, BiS, HgF, LaO, LaS, LuO, LuS, PbF, and YbF: These are all free radicals with heavy nuclei and are therefore prime candidates for production in a buffer gas cooled beam. There are even some molecules which have already been discussed, such as YbF and BaF (Table I), for which using a buffer gas beam can deliver over 100 times the brightness of a supersonic beam, with a slower forward velocity (allowing for the same time T with a shorter apparatus, easing technical requirements).…”

Calculation of nuclear-spin-dependent parity nonconservation ins–dtransitions of Ba+, Yb

“…In the end of section II we introduced the notations S 1 , S 2 , S 3 and S 4 for these terms (see Eqs. (8,9,10,11)). The terms involving the p 1/2 states are S 1 and S 3 , the terms with the p 3/2 states are S 2 and S 4 .…”

“…the contribution from nuclear anapole moment (see, e.g. reviews [6,9]). The study of the PNC for a chain of isotopes does not require atomic calculations and can deliver useful information about either neutron distribution or new physics beyond standard model (see, e.g.…”