Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Strong constraints on the rare decays Bs -> mu+ mu- and B0 -> mu+ mu-   A search for Bs -> mu+ mu- and B0 -> mu+ mu- decays is performed using 1.0
fb^-1 of pp collision data collected at \sqrt{s}=7 TeV with the LHCb experiment
at the Large Hadron Collider. For both decays the number of observed events is
consistent with expectation from background and Standard Model signal
predictions. Upper limits on the branching fractions are determined to be BR(Bs
-> mu+ mu-) < 4.5 (3.8) x 10^-9 and BR(B0 -> mu+ mu-) < 1.0 (0.81) x 10^-9 at
95% (90%) confidence level.

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The categories of this paper are: supr-con
31
The categories of this paper are: ao-sci
32
The categories of this paper are: atom-ph
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The categories of this paper are: eess
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The categories of this paper are: adap-org
2
The categories of this paper are: math
20
The categories of this paper are: acc-phys
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The categories of this paper are: solv-int
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The categories of this paper are: q-fin
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The categories of this paper are: q-bio
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The categories of this paper are: cond-mat
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The categories of this paper are: patt-sol
1
The categories of this paper are: cs
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The categories of this paper are: bayes-an
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The categories of this paper are: alg-geom
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The categories of this paper are: cmp-lg