Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Time-Dependent {\boldmath $CP$}-Violating Asymmetry in
  $B^0\to\rho^0\gamma$ Decays   We report the first measurement of CP-violation parameters in
  $B^0\to\rho^0\gamma$ decays based on a data sample of $657\times 10^6
B\bar{B}$ pairs collected with the Belle detector at the KEKB asymmetric-energy
$e^+ e^-$ collider. The flavor of the $B$ meson is identified from the decay
products of the accompanying $B$ meson. We obtain the time-dependent and direct
CP-violating parameters, $\cals_{\rhoz\gamma} = -0.83\pm 0.65(stat)\pm
0.18(syst)$ and $\cala_{\rhoz\gamma} = -0.44\pm 0.49(stat)\pm 0.14(syst)$,
respectively.

37
The categories of this paper are: supr-con
15
The categories of this paper are: nucl-ex
33
The categories of this paper are: plasm-ph
3
The categories of this paper are: physics
34
The categories of this paper are: chem-ph
24
The categories of this paper are: dg-ga
23
The categories of this paper are: solv-int
6
The categories of this paper are: astro-ph
18
The categories of this paper are: econ
14
The categories of this paper are: math-ph
2
The categories of this paper are: math
28
The categories of this paper are: alg-geom
27
The categories of this paper are: comp-gas
22
The categories of this paper are: chao-dyn
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The categories of this paper are: funct-an
9
The categories of this paper are: nlin