Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Evidence of B0 --> rho0 pi0   We present the first evidence of the decay B0 --> rho0 pi0, using 140fb^-1 of
data collected at the Upsilon(4S) resonance with the Belle detector at the KEKB
asymmetric e+e- collider. We detect a signal with a significance of 3.5
standard deviations, and measure the branching fraction to be Br(B0 ->- rho0
pi0) = (5.1 +/- 1.6(stat) +/- 0.9(syst))*10^-6.

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The categories of this paper are: nucl-th
27
The categories of this paper are: comp-gas
36
The categories of this paper are: cmp-lg
21
The categories of this paper are: adap-org
17
The categories of this paper are: q-fin
1
The categories of this paper are: cs
22
The categories of this paper are: chao-dyn
31
The categories of this paper are: ao-sci
10
The categories of this paper are: q-bio
30
The categories of this paper are: q-alg
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The categories of this paper are: nucl-ex
6
The categories of this paper are: astro-ph
34
The categories of this paper are: chem-ph
25
The categories of this paper are: patt-sol
9
The categories of this paper are: nlin
5
The categories of this paper are: gr-qc