Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Search for lepton-flavor violating decays $D^{0}\rightarrow
  X^{0}e^{\pm}\mu^{\mp}$   We present a search for seven lepton-flavor-violating neutral charm decays of
the type $D^{0}\rightarrow X^{0} e^{\pm} \mu^{\mp}$, where $X^{0}$ represents a
$\pi^{0}$, $K^{0}_{\rm S}$, $\bar{K^{*0}}$, $\rho^{0}$, $\phi$, $\omega$, or
$\eta$ meson. The analysis is based on $468$ fb$^{-1}$ of $e^+e^-$ annihilation
data collected at or close to the $\Upsilon(4S)$ resonance with the BaBar
detector at the SLAC National Accelerator Laboratory. No significant signals
are observed, and we establish 90\% confidence level upper limits on the
branching fractions in the range $(5.0 - 22.5)\times 10^{-7}$. The limits are
between one and two orders of magnitude more stringent than previous
measurements.

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The categories of this paper are: nlin
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The categories of this paper are: q-fin
2
The categories of this paper are: math
7
The categories of this paper are: hep-th
12
The categories of this paper are: nucl-th
33
The categories of this paper are: plasm-ph
14
The categories of this paper are: math-ph
28
The categories of this paper are: alg-geom
23
The categories of this paper are: solv-int
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The categories of this paper are: nucl-ex
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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: hep-lat
13
The categories of this paper are: quant-ph
27
The categories of this paper are: comp-gas
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The categories of this paper are: q-bio