Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Pure Leptonic Radiative Decays $B^\pm, D_s\to\ell\nu\gamma$ and the
  Annihilation Graph   Pure leptonic radiative decays of heavy-light mesons are calculated using a
very simple non-relativistic model. Dominant contribution originates from
photon emission from light initial quark. We find
$BR(B^\pm\to\ell\nu\gamma)\sim3.5\times10^{-6}$ and $BR(D_s\to
\ell\nu\gamma)\sim1.7 \times10^{-4}$. The importance of these reactions to
clarify the dynamics of the annihilation graph is emphasized.

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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: comp-gas
10
The categories of this paper are: q-bio
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The categories of this paper are: nucl-ex
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The categories of this paper are: eess
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The categories of this paper are: chem-ph
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The categories of this paper are: patt-sol
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The categories of this paper are: ao-sci
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The categories of this paper are: quant-ph
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The categories of this paper are: cond-mat
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The categories of this paper are: bayes-an
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The categories of this paper are: gr-qc
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The categories of this paper are: q-fin
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The categories of this paper are: chao-dyn
2
The categories of this paper are: math