Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Search for lepton-flavor-violating tau-lepton decays to $\ell\gamma$ at
  Belle   Charged lepton flavor violation is forbidden in the Standard Model but
possible in several new physics scenarios. In many of these models, the
radiative decays $\tau^{\pm}\rightarrow\ell^{\pm}\gamma$ ($\ell=e,\mu$) are
predicted to have a sizeable probability, making them particularly interesting
channels to search at various experiments. An updated search via
$\tau^{\pm}\rightarrow\ell^{\pm}\gamma$ using full data of the Belle
experiment, corresponding to an integrated luminosity of 988 fb$^{-1}$, is
reported for charged lepton flavor violation. No significant excess over
background predictions from the Standard Model is observed, and the upper
limits on the branching fractions, $\mathcal{B}(\tau^{\pm}\rightarrow
\mu^{\pm}\gamma)$ $\leq$ $4.2\times10^{-8}$ and
$\mathcal{B}(\tau^{\pm}\rightarrow e^{\pm}\gamma)$ $\leq$ $5.6\times10^{-8}$,
are set at 90\% confidence level.

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The categories of this paper are: q-alg
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The categories of this paper are: physics
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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: nucl-th
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The categories of this paper are: econ
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The categories of this paper are: hep-ph
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The categories of this paper are: cond-mat
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The categories of this paper are: alg-geom
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The categories of this paper are: nucl-ex
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The categories of this paper are: gr-qc
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The categories of this paper are: math-ph
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The categories of this paper are: chao-dyn
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The categories of this paper are: acc-phys
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The categories of this paper are: supr-con
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The categories of this paper are: hep-lat