Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Determining alpha_s from the hyperfine splitting mUpsilon(1S)-mEta(b)   The measurement of the eta_b mass, together with a QCD result for the
hyperfine splitting E_{HFS}=M_{Upsilon(1S)}-M_{eta_b}, allows us to determine
the strong coupling constant alpha_s at a low energy scale. The result
alpha_s(M_{Upsilon(1S)})=0.197\pm 0.002_{Delta E_{HFS}^{exp}} \pm
0.002_{scheme} \pm 0.002_{delta <G^2>} \pm 0.006_{delta m_b} \pm 0.005_{ho},
alpha_s(M_{Z^0})=0.124\pm 0.001_{Delta E_{HFS}^{exp}} \pm 0.001_{scheme} \pm
0.001_{delta <G^2>} \pm 0.003_{delta m_b} \pm 0.002_{ho}, is compatible with
the current world average of alpha_s reported by the Particle Data Group, and
shows that the experimental lowest-lying \bar b b hyperfine splitting can be
reproduced in terms of a perturbative and nonperturbative QCD contribution.

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The categories of this paper are: chem-ph
9
The categories of this paper are: nlin
2
The categories of this paper are: math
24
The categories of this paper are: dg-ga
10
The categories of this paper are: q-bio
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The categories of this paper are: supr-con
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The categories of this paper are: q-alg
15
The categories of this paper are: nucl-ex
5
The categories of this paper are: gr-qc
19
The categories of this paper are: eess
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The categories of this paper are: atom-ph
7
The categories of this paper are: hep-th
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The categories of this paper are: stat
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The categories of this paper are: adap-org
3
The categories of this paper are: physics
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The categories of this paper are: funct-an