Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Quasiclassical theory of quantum defect and spectrum of highly excited
  rubidium atoms   We report on a significant discrepancy between recently published highly
accurate variational calculations and precise measurements of the spectrum of
Rydberg states in $^{87}$Rb on the energy scale of fine splitting. Introducing
a modified effective single-electron potential we determine the spectrum of the
outermost bound electron from a standard WKB approach. Overall very good
agreement with precise spectroscopic data is obtained.

36
The categories of this paper are: cmp-lg
5
The categories of this paper are: gr-qc
21
The categories of this paper are: adap-org
31
The categories of this paper are: ao-sci
0
The categories of this paper are: hep-ph
30
The categories of this paper are: q-alg
24
The categories of this paper are: dg-ga
9
The categories of this paper are: nlin
2
The categories of this paper are: math
22
The categories of this paper are: chao-dyn
34
The categories of this paper are: chem-ph
12
The categories of this paper are: nucl-th
25
The categories of this paper are: patt-sol
16
The categories of this paper are: stat
26
The categories of this paper are: bayes-an
7
The categories of this paper are: hep-th