Towards improved measurements of parity violation in atomic ytterbium

Abstract

We report on progress towards performing precision measurements of parity violation in Yb, in which the theoretical prediction for a strong weak-interaction-induced effect in the 6s^{2} ^{1}S_{0} \rightarrow 5d6s ^{3}D_{1} optical transition at 408 nm has already been confirmed, with a measurement of the effect at the \approx 10 % level of accuracy. With a new atomic-beam apparatus offering enhanced sensitivity, we are aiming at precisely determining the parity violation observable in Yb, which will allow us to probe the distributions of neutrons in different isotopes, investigate physics beyond the Standard Model, as well as to study intra-nucleus weak interactions, through an observation of the anapole moment of Yb nuclei with nonzero spin. We present the experimental principle employed to probe atomic parity violation, describe our new apparatus, and discuss the attained experimental sensitivity as well as the methods for characterizing systematics in these measurements

Probing Low-Mass Vector Bosons with Parity Nonconservation and Nuclear Anapole Moment Measurements in Atoms and Molecules

“…1). Ongoing and future PNC experiments with atoms [47][48][49][50][51] and molecules [52,53] may improve on the level of sensitivity demonstrated in the present work. In particular, atomic PNC experiments that involve the mixing of atomic states of high angular momentum (e.g., in Dy [48]) may be particularly sensitive to the electron-nucleon interaction mediated by a low-mass vector boson, since a large centrifugal barrier does not necessarily suppress PNC effects in this case (in contrast to the case of a highmass vector boson, where the effects arise mainly in the vicinity of the atomic nucleus).…”

Hyperfine constants and line separations for the S01−P13 intercombination line in neutral ytterbium with sub-Doppler resolution

“…In parallel, ytterbium has been used to develop one of the world's most accurate atomic frequency references [15][16][17][18][19]. Ytterbium gained attention in the investigation of atomic parity nonconservation [20,21] when the level of violation was shown to be about one hundred times stronger than in Cs [22]. Such experiments examine nuclear physics at low energy and are a means to explore physical behaviour beyond the Standard Model of elementary particles [23][24][25][26].…”

Correlation trends in the nuclear anapole moment interaction of the Be atom in BeCl

“…The nuclear anapole moment effect has been observed in the 133 Cs atom [8,9]. Some measurements have also been proposed on other atoms, such as 137 Ba [10], 163 Dy [11], 171 Yb [12], and 212 Fr [13]. In diatomic molecules with a 2 Σ 1/2 ground state, the effect is strongly enhanced because of close-lying molecular levels with opposite parity, where degeneracy can be very easily occur in external fields, leading to a dramatic amplification of the tiny parity-violating effect [14].…”