Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Measurements of the Branching Fractions and Helicity Amplitudes in B -->
  D* rho Decays   Using 9.1 fb-1 of e+ e- data collected at the Upsilon(4S) with the CLEO
detector using the Cornell Electron Storage Ring, measurements are reported for
both the branching fractions and the helicity amplitudes for the decays B- ->
D*0 rho- and B0bar -> D*+ rho-. The fraction of longitudinal polarization in
B0bar -> D*+ rho- is found to be consistent with that in B0bar -> D*+ l- nubar
at q^2 = M^2_rho, indicating that the factorization approximation works well.
The longitudinal polarization in the B- mode is similar. The measurements also
show evidence of non-trivial final-state interaction phases for the helicity
amplitudes.

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The categories of this paper are: math
36
The categories of this paper are: cmp-lg
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The categories of this paper are: dg-ga
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The categories of this paper are: nucl-ex
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The categories of this paper are: supr-con
10
The categories of this paper are: q-bio
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The categories of this paper are: patt-sol
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The categories of this paper are: eess
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The categories of this paper are: solv-int
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The categories of this paper are: atom-ph
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The categories of this paper are: comp-gas
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The categories of this paper are: plasm-ph
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The categories of this paper are: q-fin
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The categories of this paper are: stat
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The categories of this paper are: bayes-an
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The categories of this paper are: quant-ph