Parity violation in atomic ytterbium: Experimental sensitivity and systematics

Abstract

We present a detailed description of the observation of parity violation in the 1 S 0 -3 D 1 408-nm forbidden transition of ytterbium, a brief report of which appeared earlier. Linearly polarized 408-nm light interacts with Yb atoms in crossed E and B fields. The probability of the 408-nm transition contains a parity-violating term, proportional to (E · B)[(E × E) · B], arising from interference between the parity-violating amplitude and the Stark amplitude due to the E field (E is the electric field of the light). The transition probability is detected by measuring the population of the 3 P 0 state, to which 65% of the atoms excited to the 3 D 1 state spontaneously decay. The population of the 3 P 0 state is determined by resonantly exciting the atoms with 649-nm light to the 6s7s 3 S 1 state and collecting the fluorescence resulting from its decay. Systematic corrections due to E-field and B-field imperfections are determined in auxiliary experiments. The statistical uncertainty is dominated by parasitic frequency excursions of the 408-nm excitation light due to the imperfect stabilization of the optical reference with respect to the atomic resonance. The present uncertainties are 9% statistical and 8% systematic. Methods of improving the accuracy for future experiments are discussed.

Constraints on the symmetry energy and neutron skins from experiments and theory

“…Therefore, constraining the neutron skin thickness may be important for low-energy APV tests of the standard model. Conversely, one can measure APV for a range of isotopes to deduce neutron radii [14].…”

Measurement of the Neutron Radius ofPb208through Parity Violation in Electron Scattering

“…A future low-energy test of the standard model may involve the combination of a precise APV experiment along with PV electron scattering to constrain R n [28]. Alternatively, measuring APV for a range of isotopes could provide information on neutron densities [30].…”

Atomic parity non-conservation: the francium anapole project of the FrPNC collaboration at TRIUMF

“…The following are examples and do not intend to cover all the developments in the field: The Bouchiat group in Paris worked on the highly forbidden 6s to 7s electric dipole transition in a cesium cell, but detected the occurrence of the transition using stimulated emission rather than fluorescence [25]. The Budker group in Berkeley has completed a first round of measurements in ytterbium [26][27][28][29], has proposed APNC measurements with twophoton transitions [30], and is pursuing dysprosium [31,32]. There is an on-going experiment in the Blinov and Fortson group in Seattle using a single barium ion [33][34][35].…”