Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Observation of B+ -> K+ eta gamma   We report measurements of radiative B decays with K eta gamma final states,
using a data sample of 253 /fb recorded at the Upsilon(4S) resonance with the
Belle detector at the KEKB e+e- storage ring. We observe B+ -> K+ eta gamma for
the first time with a branching fraction of (8.4 +- 1.5(stat) +1.2 -0.9(syst))
X 10^{-6} for M(Keta) < 2.4 GeV/c^2, and find evidence of B0 -> K0 eta gamma.
We also search for B -> K3*(1780) gamma.

19
The categories of this paper are: eess
14
The categories of this paper are: math-ph
32
The categories of this paper are: atom-ph
33
The categories of this paper are: plasm-ph
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The categories of this paper are: adap-org
29
The categories of this paper are: funct-an
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The categories of this paper are: q-bio
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The categories of this paper are: econ
11
The categories of this paper are: hep-lat
35
The categories of this paper are: mtrl-th
12
The categories of this paper are: nucl-th
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The categories of this paper are: astro-ph
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The categories of this paper are: q-fin
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The categories of this paper are: bayes-an
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The categories of this paper are: alg-geom
36
The categories of this paper are: cmp-lg