QED calculation of the dipole polarizability of helium atom
QED calculation of the dipole polarizability of helium atom
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DOI：
10.1103/physreva.101.022505
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发表时间：
2019-12
影响因子：
2.9
通讯作者：
M. Puchalski;K. Szalewicz;M. Lesiuk;B. Jeziorski
中科院分区：
文献类型：
--
作者：
M. Puchalski;K. Szalewicz;M. Lesiuk;B. Jeziorski
考虑有限核质量的影响，计算了QED对He原子偶极极化率的贡献。Bethe对数的二阶电场导数的计算最具挑战性的贡献是使用两种不同的方法：Schwartz的积分表示法和Goldman和Drake的状态总和方法。这两种计算的结果是一致的，尽管前一种方法被证明要准确得多。得到的Bethe对数的电场导数等于0.048 5572(14)原子单位，这证实了在先前唯一的计算中发现的这个量的小量级[G.\L，B.Jeziorski，和K.Szalewicz，Phys.莱特牧师。92,233001(2004年)]，但与之相差约5%.对这种差异的原因进行了解释。在精细结构常数$\EnsureMath{\Alpha}$中的数量级的QED总校正等于$30.6671(1)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}6}$，包括Bethe对数的电场导数的$0.1822\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}6}$贡献和有限核质量的$0.011\phantom{\rule{0.16em}{0ex}}12(1)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}6}$修正，所有的值都以原子为单位。由此得到的氦-4摩尔极化率的理论值为$0.517\phantom{\rule{0.16em}{0ex}}254\phantom{\rule{0.16em}{0ex}}08(5)\phantom{\rule{4pt}{0ex}}{\mathrm{cm}}^{3}/\text{mol}$，误差估计值主要由数量级或更高阶的量子电动力学修正的不确定性所主导。我们的值与最近实验测定的结果$0.517\phantom{\rule{0.16em}{0ex}}254\phantom{\rule{0.16em}{0ex}}4(10)\phantom{\rule{0.28em}{0ex}}{\mathrm{cm}}^{3}/\text{mol}$一致，但精度要高一个数量级[C.Gaiser和B.Fellmuth，Phys.莱特牧师。120,123203(2018年)]。
The QED contribution to the dipole polarizability of the $^{4}\mathrm{He}$ atom was computed, including the effect of finite nuclear mass. The computationally most challenging contribution of the second electric-field derivative of the Bethe logarithm was obtained using two different methods: the integral representation method of Schwartz and the sum-over-states approach of Goldman and Drake. The results of both calculations are consistent, although the former method turned out to be much more accurate. The obtained value of the electric-field derivative of the Bethe logarithm, equal to 0.048 557 2(14) in atomic units, confirms the small magnitude of this quantity found in the only previous calculation [G. \L{}ach, B. Jeziorski, and K. Szalewicz, Phys. Rev. Lett. 92, 233001 (2004)], but differs from it by about 5%. The origin of this difference is explained. The total QED correction of the order of ${\ensuremath{\alpha}}^{3}$ in the fine-structure constant $\ensuremath{\alpha}$ amounts to $30.6671(1)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}6}$, including the $0.1822\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}6}$ contribution from the electric-field derivative of the Bethe logarithm and the $0.011\phantom{\rule{0.16em}{0ex}}12(1)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}6}$ correction for the finite nuclear mass, with all values in atomic units. The resulting theoretical value of the molar polarizability of helium-4 is $0.517\phantom{\rule{0.16em}{0ex}}254\phantom{\rule{0.16em}{0ex}}08(5)\phantom{\rule{4pt}{0ex}}{\mathrm{cm}}^{3}/\text{mol}$ with the error estimate dominated by the uncertainty of the QED corrections of order ${\ensuremath{\alpha}}^{4}$ and higher. Our value is in agreement with but an order of magnitude more accurate than the result $0.517\phantom{\rule{0.16em}{0ex}}254\phantom{\rule{0.16em}{0ex}}4(10)\phantom{\rule{0.28em}{0ex}}{\mathrm{cm}}^{3}/\text{mol}$ of the most recent experimental determination [C. Gaiser and B. Fellmuth, Phys. Rev. Lett. 120, 123203 (2018)].