Parity violation induced by weak neutral currents in atomic physics. part II
Parity violation induced by weak neutral currents in atomic physics. part II
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原子物理学中弱中性电流引起的宇称不守恒。
DOI：
10.1051/jphys:01975003606049300
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发表时间：
1975
期刊：
影响因子：
--
通讯作者：
C. Bouchiat
中科院分区：
文献类型：
--
作者：
M. Bouchiat;C. Bouchiat
本文的第一部分详细介绍了通过宇称破坏电子-核短程电势 Vp.v 来评估碱性单光子 S-S 跃迁中引起的电偶极子振幅。与弱中性电流有关。提出了两种方法：第一种方法涉及对 P 状态与 S 状态混合的贡献进行显式求和，并结合有关 S-P 电偶极子振幅的最佳可用信息。第二种方法在数学上更优雅，借助格林函数技术避免了 P 态上的任何显式求和，并且假设忽略了一些自旋轨道校正，则得出一个相当简单的公式，其中涉及文献中列出的库仑积分以及 S 波和 P 波的内插量子缺陷。第二部分致力于描述检测辐射 S-S 跃迁中引起的宇称破坏的可能方法，并简要讨论可能成为实验困难来源的物理过程。本文的最后一部分对静电场对辐射 S-S 跃迁的影响进行了理论分析。对铯情况下感应电偶极子振幅的评估表明，对于大于 10 V/cm 的电场，它将与磁偶极子振幅竞争。这两个振幅之间的干涉效应会产生最终原子态的电子极化，该极化与静电场与光子动量的矢量积成正比，在典型情况下，该极化可能高达 64%；对这种有趣且相当奇特的效应的测量将导致磁偶极子振幅符号的确定。此外，宇称破坏可以通过电子极化对入射光子的圆极化状态的依赖性来体现。
The first part of this paper gives a detailed account of the evaluation of the electric dipole amplitude induced in alkali one-photon S-S transitions, by the parity violating electron-nucleus short range potential Vp.v. associated with the weak neutral currents. Two methods are presented : the first involves an explicit sum over the contributions of the P-states admixed with the S-states and incorporates the best information available on S-P electric dipole amplitudes. The second method, mathematically more elegant, avoids with the help of Green's function techniques any explicit sum over the P states, and, provided that some spin-orbit corrections are neglected, leads to a fairly simple formula involving Coulomb integrals tabulated in the literature and the interpolated quantum defects for S and P waves. The second part is devoted to a description of possible ways to detect parity violation induced in radiative S-S transitions, with a brief discussion of physical processes which could be a source of experimental difficulty. The last section of the paper deals with a theoretical analysis of the influence of a static electric field on the radiative S-S transitions. An evaluation of the induced electric dipole amplitude in the case of cesium indicates that it will compete with the magnetic dipole amplitude for electric fields larger than 10 V/cm. An interference effect between these two amplitudes gives rise to an electronic polarization in the final atomic state proportional to the vector product of the static electric field by the photon momentum which, in a typical case, could be as large as 64 %; the measurement of this interesting and rather peculiar effect will lead to a determination of the sign of the magnetic dipole amplitude. Moreover parity violation could manifest itself by a dependence of this electron polarization on the state of circular polarization of the incident photon.