Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: $g$ Factor of Lithiumlike Silicon: New Challenge to Bound-State QED   The recently established agreement between experiment and theory for the $g$
factors of lithiumlike silicon and calcium ions manifests the most stringent
test of the many-electron bound-state quantum electrodynamics (QED) effects in
the presence of a magnetic field. In this Letter, we present a significant
simultaneous improvement of both theoretical $g_\text{th} =
2.000\,889\,894\,4\,(34)$ and experimental $g_\text{exp} =
2.000\,889\,888\,45\,(14)$ values of the $g$ factor of lithiumlike silicon
$^{28}$Si$^{11+}$. The theoretical precision now is limited by the
many-electron two-loop contributions of the bound-state QED. The experimental
value is accurate enough to test these contributions on a few percent level.

11
The categories of this paper are: hep-lat
19
The categories of this paper are: eess
32
The categories of this paper are: atom-ph
33
The categories of this paper are: plasm-ph
35
The categories of this paper are: mtrl-th
14
The categories of this paper are: math-ph
13
The categories of this paper are: quant-ph
8
The categories of this paper are: hep-ex
31
The categories of this paper are: ao-sci
26
The categories of this paper are: bayes-an
12
The categories of this paper are: nucl-th
6
The categories of this paper are: astro-ph
27
The categories of this paper are: comp-gas
18
The categories of this paper are: econ
34
The categories of this paper are: chem-ph
4
The categories of this paper are: cond-mat