Measurements of parity violation in atomic ytterbium

在电弱相互作用的研究中，原子宇称破坏（PV）实验是一个强大的工具，提供了有关标准模型和低能核物理的有价值的信息。镱（Yb）是此类研究的优秀系统，由于其强大的PV效应（迄今为止在任何原子系统中观察到的最大效应）和许多稳定同位素的可用性。这使得对Yb同位素链进行高精度测量的可能性变得触手可及，这将作为这些不同同位素之间中子皮肤变化的探针，以及标准模型之外的物理学探针。此外，确定核自旋对Yb中PV效应的贡献将是对核的再极点矩的观测，并将产生与强子弱相互作用有关的核子-核子弱介子耦合的信息。最近完成的测量导致了原子PV中同位素变化的首次观测，我们已完全准备好解决我们Yb计划的主要科学目标：A.确定Yb原子核PV效应的自旋相关贡献，并提取核的再极点矩。这将通过精确测量自旋核同位素（171 Yb，173 Yb）超精细流形中PV效应的差异来实现。探索Yb同位素链中子皮的变化和标准模型之外的物理。这些目标将通过精确测量Yb同位素链中PV效应的比率来实现。

In the study of electro-weak interactions, atomic parity violation (PV) experiments form a powerful tool, providing valuable information about the Standard Model and low-energy nuclear physics. Ytterbium (Yb) is an excellent system for such studies, due to its strong PV effect (largest effect observed in any atomic system to date) and the availability of many stable isotopes. This brings within reach the possibility to perform high-precision measurements on a chain of Yb isotopes, which would serve as a probe of the neutron skin variation among these different isotopes, and a probe of physics beyond the Standard Model. In addition, a determination of the nuclear spin-dependent contributions to the PV effect in Yb would be an observation of the nuclear anapole moment, and would yield information about nucleon-nucleon weak meson couplings associated with hadronic weak interactions.Having recently completed measurements that resulted in the first observation of isotopic variation in atomic PV, we are fully prepared to tackle the main scientific objectives of our Yb programme:A. To determine the spin-dependent contributions to the PV effect and extract the nuclear anapole moment of the Yb nucleus. This will be achieved through precision measurements of the difference of the PV effect in the hyperfine manifold of the spinful nuclear isotopes (171Yb, 173Yb).B. To probe the variation of the neutron skin in a chain of Yb isotopes and physics beyond the Standard Model. These goals will be accomplished through precision measurements of the ratio of PV effects in a chain of Yb isotopes.