Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Measurement of the B --> X_s gamma Branching Fraction and Photon Energy
  Spectrum using the Recoil Method   We present a measurement of the branching fraction and photon energy spectrum
for the decay B --> X_s gamma using data from the BaBar experiment. The data
sample corresponds to an integrated luminosity of 210 fb^{-1}, from which
approximately 680 000 BB events are tagged by a fully reconstructed hadronic
decay of one of the B mesons. In the decay of the second B meson, an isolated
high--energy photon is identified. We measure BR(B --> X_s gamma) = (3.66 +-
0.85_{stat} +- 0.60_{syst}) x 10^{-4} for photon energies E_gamma above 1.9 GeV
in the B rest frame. From the measured spectrum we calculate the first and
second moments for different minimum photon energies, which are used to extract
the heavy-quark parameters m_b and mu_{pi}^2. In addition, measurements of the
direct CP asymmetry and isospin asymmetry are presented.

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The categories of this paper are: chao-dyn
1
The categories of this paper are: cs
11
The categories of this paper are: hep-lat
36
The categories of this paper are: cmp-lg
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The categories of this paper are: atom-ph
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The categories of this paper are: q-fin
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The categories of this paper are: funct-an
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The categories of this paper are: alg-geom
7
The categories of this paper are: hep-th
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The categories of this paper are: math-ph
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The categories of this paper are: nucl-th
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The categories of this paper are: patt-sol
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The categories of this paper are: econ
3
The categories of this paper are: physics
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The categories of this paper are: stat
13
The categories of this paper are: quant-ph