Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: $P$-wave contributions to $B\to\psi\pi\pi$ decays in perturbative QCD
  approach   We present the differential branching fractions for the $B\rightarrow \psi
\pi\pi$ decays with the charmonia $\psi=J/\psi,\psi(2S)$ in the invariant mass
of the $P$-wave pion pairs in the perturbative QCD approach. The two-pion
distribution amplitudes (DAs) corresponding to both longitudinal and transverse
polarizations are constructed to capture important final state interactions in
the processes. The time-like form factors, normalizing the two-pion DAs,
contains contributions from the $\rho$ resonance and radial excitations fitted
to the BaBar data. Given the hadronic parameters for the two-pion DAs
associated with the longitudinal polarization which were determined in our
previous study, and tuning those associated with the transverse polarization,
we accommodate well the observed branching ratios and polarization fractions of
the $B\rightarrow J/\psi \pi\pi$ decays. Our predictions for the $B\rightarrow
\psi(2S) \pi\pi$ modes from the same set of parameters can be tested in future
LHCb and BelleII experiments. We also investigate the sources of theoretical
uncertainties in our calculation.

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The categories of this paper are: atom-ph
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The categories of this paper are: acc-phys
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The categories of this paper are: q-fin
4
The categories of this paper are: cond-mat
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The categories of this paper are: q-bio
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The categories of this paper are: hep-lat
5
The categories of this paper are: gr-qc
12
The categories of this paper are: nucl-th
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The categories of this paper are: comp-gas
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The categories of this paper are: econ
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The categories of this paper are: math-ph
7
The categories of this paper are: hep-th
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The categories of this paper are: supr-con
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The categories of this paper are: cmp-lg
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The categories of this paper are: patt-sol
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The categories of this paper are: dg-ga