Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Unravelling soft components in the shape function for inclusive B decays   In the heavy-quark limit, the decay spectrum for radiative and semileptonic
inclusive B-meson decays is determined by a universal structure function, i.e.
the shape function. We study the constraints on the bilocal heavy-quark
operator for the shape function from the QCD equations of motion and
heavy-quark symmetry, and we obtain a new basis of nonlocal operators that
reveals relevant soft components in the shape function. Those nonlocal
operators represent the ``kinetic energy distribution'' of the b-quark inside
the B-meson and the four-parton correlations with additional quarks and gluons.
A corresponding local operator basis relevant for relating the shape function
to HQET parameters is also given, and novel effects of the quark-gluon
correlations are discussed.

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The categories of this paper are: dg-ga
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The categories of this paper are: comp-gas
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The categories of this paper are: bayes-an
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The categories of this paper are: eess
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The categories of this paper are: supr-con
13
The categories of this paper are: quant-ph
6
The categories of this paper are: astro-ph
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The categories of this paper are: patt-sol
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The categories of this paper are: solv-int
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The categories of this paper are: acc-phys
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The categories of this paper are: nucl-th
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The categories of this paper are: math-ph
4
The categories of this paper are: cond-mat
30
The categories of this paper are: q-alg
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The categories of this paper are: adap-org
3
The categories of this paper are: physics