Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: B => \pi \pi \ell \nu decays in a QCD relativistic potential model   In the framework of a QCD relativistic potential model we evaluate the form
factors describing the exclusive decay B => \pi\pi \ell \nu. The calculation is
performed in a phase space region far away from the resonances and therefore is
complementary to other decay mechanisms where the pions are produced by
intermediate particles, e.g. in the chiral approach. We give an estimate of the
contribution of the non resonant channel of the order of BR(B- => \pi+ \pi-
\ell \nu) \approx 2.2 x 10^(-4).

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The categories of this paper are: nucl-th
6
The categories of this paper are: astro-ph
5
The categories of this paper are: gr-qc
1
The categories of this paper are: cs
10
The categories of this paper are: q-bio
27
The categories of this paper are: comp-gas
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The categories of this paper are: q-fin
13
The categories of this paper are: quant-ph
29
The categories of this paper are: funct-an
9
The categories of this paper are: nlin
23
The categories of this paper are: solv-int
3
The categories of this paper are: physics
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The categories of this paper are: adap-org
32
The categories of this paper are: atom-ph
33
The categories of this paper are: plasm-ph
35
The categories of this paper are: mtrl-th