Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Nuclear recoil effect in the Lamb shift of light hydrogen-like atoms   We report high-precision calculations of the nuclear recoil effect to the
Lamb shift of hydrogen-like atoms to the first order in the electron-nucleus
mass ratio and to all orders in the nuclear binding strength parameter
$Z\alpha$. The results are in excellent agreement with the known terms of the
$Z\alpha$ expansion and allow an accurate identification of the nonperturbative
higher-order remainder. For hydrogen, the higher-order remainder was found to
be much larger than anticipated. This result resolves the long-standing
disagreement between the numerical all-order and the analytical
$Z\alpha$-expansion approaches to the recoil effect and completely removes the
second-largest theoretical uncertainty in the hydrogen Lamb shift of the $1S$
and $2S$ states.

8
The categories of this paper are: hep-ex
0
The categories of this paper are: hep-ph
22
The categories of this paper are: chao-dyn
28
The categories of this paper are: alg-geom
15
The categories of this paper are: nucl-ex
18
The categories of this paper are: econ
35
The categories of this paper are: mtrl-th
14
The categories of this paper are: math-ph
25
The categories of this paper are: patt-sol
37
The categories of this paper are: supr-con
5
The categories of this paper are: gr-qc
20
The categories of this paper are: acc-phys
7
The categories of this paper are: hep-th
27
The categories of this paper are: comp-gas
11
The categories of this paper are: hep-lat
23
The categories of this paper are: solv-int