Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Measurement of B0->Ds(*)+D*- branching fractions and polarization in the
  decay B0->Ds*+D*- with a partial reconstruction technique   We present measurements of the decays B0->Ds(*)+D*-, using data recorded by
the BABAR detector in 1999 and 2000, consisting of 20.8 fb^-1. The analysis is
conducted with a partial reconstruction technique, in which only the Ds(*)+ and
the soft pion from the D*- decay are reconstructed. From the observed rates, we
measure the branching fractions BR(B0->Ds+D*-) = (1.03 +- 0.14 +- 0.13 +-
0.26)% and BR(B0->Ds*+D*-) = (1.97 +- 0.15 +- 0.30 +- 0.49)%, where the first
error is statistical, the second is systematic, and the third is the error due
to the Ds+->phi pi+ branching fraction uncertainty. From the B0->Ds*+D*-
angular distributions, we measure the fraction of longitudinal polarization
Gamma_L/Gamma = (51.9 +- 5.0 +- 2.8)%, which is consistent with the theoretical
prediction, based on factorization. These results are preliminary.

31
The categories of this paper are: ao-sci
1
The categories of this paper are: cs
2
The categories of this paper are: math
21
The categories of this paper are: adap-org
9
The categories of this paper are: nlin
3
The categories of this paper are: physics
37
The categories of this paper are: supr-con
18
The categories of this paper are: econ
11
The categories of this paper are: hep-lat
15
The categories of this paper are: nucl-ex
35
The categories of this paper are: mtrl-th
23
The categories of this paper are: solv-int
12
The categories of this paper are: nucl-th
34
The categories of this paper are: chem-ph
19
The categories of this paper are: eess
27
The categories of this paper are: comp-gas