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arXiv 1209.5142physics.atom-phhep-ph
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氦原子P态g因子的量子电动力学修正

Quantum Electrodynamic Corrections to the g Factor of Helium P States

M. Puchalski, U. D. Jentschura

摘要:

朗德g因子描述了原子能级对均匀恒定磁场的外部扰动的响应。在多电子系统的情况下,主导项由相互作用μ_B*(L+2S. B)给出,其中L和S分别是轨道和自旋角动量算符,对所有电子求和。对于氦,长期存在的P态的实验-理论差异促使人们重新评估相对论量子理论和量子电动力学(QED)的高阶项。相对论修正的张量结构包括标量、矢量、对称和反对称张量分量。我们执行这些运营商在笛卡尔的基础上,张量减少,使用的方法,使我们能够分离的内部原子从外部自由度(磁场)的权利,从一开始的计算。评估过程中的笛卡尔基础上的氦本征态,使用加权和的磁投影。对于相对论修正,这导致了以前的结果使用Wigner-Eckhart定理的验证。同样的方法,应用于辐射校正(贝特对数项)导致自旋相关的校正,这是不同的单重态与三重态P状态。单重态和三重态2 P和三重态3 P的理论预测,并与实验结果进行比较。

英文摘要:

The Lande g factor describes the response of an atomic energy level to an external perturbation by a uniform and constant magnetic field. In the case of many-electron systems, the leading term is given by the interaction mu_B*(L+2S.B), where L and S are the orbital and spin angular momentum operators, respectively, summed over all electrons. For helium, a long-standing experimental-theoretical discrepancy for P states motivates a reevaluation of the higher-order terms which follow from relativistic quantum theory and quantum electrodynamics (QED). The tensor structure of relativistic corrections involves scalar, vector, and symmetric and anti-symmetric tensor components. We perform a tensorial reduction of these operators in a Cartesian basis, using an approach which allows us to separate the internal atomic from the external degrees of freedom (magnetic field) right from the start of the calculation. The evaluation proceeds in a Cartesian basis of helium eigenstates, using a weighted sum over the magnetic projections. For the relativistic corrections, this leads to a verification of previous results obtained using the Wigner-Eckhart theorem. The same method, applied to the radiative correction (Bethe logarithm term) leads to a spin-dependent correction which is different for singlet versus triplet P states. Theoretical predictions are given for singlet and triplet 2P and triplet 3P states and compared to experimental results where available.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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