Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The $D^*D \pi$ and $B^*B\pi$ couplings from light-cone sum rules   We revisit the calculation of the strong couplings $D^*D\pi$ and $B^*B\pi$
from the QCD light-cone sum rules using the pion light-cone distribution
amplitudes. The accuracy of the correlation function, calculated from the
operator product expansion near the light-cone, is upgraded by taking into
account the gluon radiative corrections to the twist-3 terms. The double
spectral density of the correlation function, including the twist-2, 3 terms at
${\cal O} (\alpha_s)$ and the twist-4 LO terms, is presented in an analytical
form for the first time. This form allows us to use various versions of the
quark-hadron duality regions in the double dispersion relation underlying the
sum rules. We predict $g_{D^*D\pi}=14.1^{+1.3}_{-1.2}$ and
$g_{B^*B\pi}=30.0^{+2.6}_{-2.4}$ when the decay constants of heavy mesons
entering the light-cone sum rule are taken from lattice QCD results. We compare
our results with the experimental value for the charmed meson coupling and with
the lattice QCD calculations.

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The categories of this paper are: atom-ph
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The categories of this paper are: ao-sci
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The categories of this paper are: adap-org
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The categories of this paper are: chem-ph
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The categories of this paper are: plasm-ph
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The categories of this paper are: mtrl-th
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The categories of this paper are: cmp-lg
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The categories of this paper are: math
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The categories of this paper are: funct-an
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The categories of this paper are: math-ph
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The categories of this paper are: quant-ph
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The categories of this paper are: cs
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The categories of this paper are: dg-ga
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The categories of this paper are: cond-mat
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The categories of this paper are: acc-phys
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The categories of this paper are: nucl-th