High-precision determination of $g$ factors and masses of $^{20}\text{Ne}^{9+}$ and $^{22}\text{Ne}^{9+}$

F. Heiße; M. Door; T. Sailer; P. Filianin; J. Herkenhoff; C. M. König; K. Kromer; D. Lange; J. Morgner; A. Rischka; Ch. Schweiger; B. Tu.; Y. N. Novikov; S. Eliseev; S. Sturm; K. Blaum

arXiv · 2310.11119

High-precision determination of $g$ factors and masses of $^{20}\text{Ne}^{9+}$ and $^{22}\text{Ne}^{9+}$

F. Heiße·M. Door·T. Sailer·P. Filianin·J. Herkenhoff·C. M. König·K. Kromer·D. Lange·J. Morgner·A. Rischka·Ch. Schweiger·B. Tu.·Y. N. Novikov·S. Eliseev·S. Sturm·K. Blaum

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Abstract

We present the measurements of individual bound electron $g$ factors of $^{20}\text{Ne}^{9+}$ and $^{22}\text{Ne}^{9+}$ on the relative level of $0.1\,\text{parts}$ per billion. The comparison with theory represents the most stringent test of bound-state QED in strong electric fields. A dedicated mass measurement results in $m\left(^{20}\text{Ne}\right)=19.992\,440\,168\,77\,(9)\,\text{u}$, which improves the current literature value by a factor of nineteen, disagrees by $4$ standard deviations and represents the most precisely measured mass value in atomic mass units. Together, these measurements yield an electron mass on the relative level of $0.1\,\text{ppb}$ with $m_{\text{e}}=5.485\,799\,090\,99\,(59) \times 10^{-4}\,\text{u}$ as well as a factor of eight improved $m\left(^{22}\text{Ne}\right)=21.991\,385\,098\,2\,(26)\,\text{u}$.

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F. Heiße, M. Door, T. Sailer, P. Filianin, J. Herkenhoff, C. M. König, K. Kromer, D. Lange, J. Morgner, A. Rischka, Ch. Schweiger, B. Tu., Y. N. Novikov, S. Eliseev, S. Sturm, K. Blaum. 2023-10-17. High-precision determination of $g$ factors and masses of $^{20}\text{Ne}^{9+}$ and $^{22}\text{Ne}^{9+}$. https://arxiv.org/abs/2310.11119

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