Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Second-order magnetic contributions to the hyperfine splitting of the
  5snd ^1D_2 states in ^87Sr   The hyperfine structure of 5snd ^1D_2 states in ^{87}Sr was studied for
principal quantum numbers 11 <= n <= 25 by Doppler-free two-photon excitation
combined with thermionic detection. Based on the more accurate data, compared
to previous results, the hyperfine structure was analysed by second order
perturbation theory using MQDT wavefunctions. As a result we find that the
surprisingly large B-factors obtained by fitting the data with the Casimir
formula do not reflect a quadrupolar interaction but rather consist
predominantly of second order magnetic dipole contributions. Further,
inconsistencies in the King plot of odd-even isotope shifts were removed by
this type of analysis. The result demonstrates the importance of higher order
effects in hyperfine splittings of excited states in atoms with two valence
electrons, even when the fine structure splitting is large compared to the
hyperfine splitting.

23
The categories of this paper are: solv-int
13
The categories of this paper are: quant-ph
30
The categories of this paper are: q-alg
6
The categories of this paper are: astro-ph
4
The categories of this paper are: cond-mat
18
The categories of this paper are: econ
15
The categories of this paper are: nucl-ex
14
The categories of this paper are: math-ph
17
The categories of this paper are: q-fin
12
The categories of this paper are: nucl-th
10
The categories of this paper are: q-bio
0
The categories of this paper are: hep-ph
37
The categories of this paper are: supr-con
33
The categories of this paper are: plasm-ph
21
The categories of this paper are: adap-org
16
The categories of this paper are: stat