Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Hyperfine Paschen-Back regime in alkali metal atoms: consistency of two
  theoretical considerations and experiment   Simple and efficient "\lambda-method" and "\lambda/2-method" (\lambda is the
resonant wavelength of laser radiation) based on nanometric-thickness cell
filled with rubidium are implemented to study the splitting of hyperfine
transitions of 85Rb and 87Rb D_1 line in an external magnetic field in the
range of B = 0.5 - 0.7 T. It is experimentally demonstrated from 20 (12) Zeeman
transitions allowed at low B-field in 85Rb (87Rb) spectra in the case of
\sigma+ polarized laser radiation, only 6 (4) remain at B > 0.5 T, caused by
decoupling of the total electronic momentum J and the nuclear spin momentum I
(hyperfine Paschen-Back regime). The expressions derived in the frame of
completely uncoupled basis (J, m_J ; I, m_I) describe very well the
experimental results for 85Rb transitions at $B > 0.6 T (that is a
manifestation of hyperfine Paschen-Back regime). A remarkable result is that
the calculations based on the eigenstates of coupled (F, m_F) basis, which
adequately describe the system for low magnetic field, also predict reduction
of number of transition components from 20 to 6 for 85Rb, and from 12 to 4 for
87Rb spectrum at B > 0.5 T. Also, the Zeeman transitions frequency shift,
frequency interval between the components and their slope versus $B$ are in
agreement with the experiment.

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The categories of this paper are: math-ph
26
The categories of this paper are: bayes-an
34
The categories of this paper are: chem-ph
31
The categories of this paper are: ao-sci
11
The categories of this paper are: hep-lat
12
The categories of this paper are: nucl-th
8
The categories of this paper are: hep-ex
35
The categories of this paper are: mtrl-th
25
The categories of this paper are: patt-sol
0
The categories of this paper are: hep-ph
5
The categories of this paper are: gr-qc
23
The categories of this paper are: solv-int
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The categories of this paper are: adap-org
32
The categories of this paper are: atom-ph
33
The categories of this paper are: plasm-ph
9
The categories of this paper are: nlin