Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Study of time-dependent CP-violation in $B^0 \to J/\psi ~\pi^0$ decay   We report a measurement of CP asymmetry parameters in the $b \to
c\bar{c}d$-transition-induced decays $B^0(\bar{B^0}) \to J/\psi pi^0$. The
analysis is based on a 140 fb$^{-1}$ data sample accumulated at the
$\Upsilon(4S)$ resonance by the Belle detector at the KEKB asymmetric-energy
$e^+ e^-$ collider. We fully reconstruct one neutral $B$ meson in the $J/\psi
~\pi^0$ final state. The accompanying $B$ meson flavor is identified by its
decay products. From the distribution of proper time intervals between the two
B decays, we obtain the following CP violation parameters: S(J/\psi \pi^0)=
-0.72 \pm0.42 (stat) \pm 0.08(syst) A(J/\psi \pi^0)= -0.01 \pm0.29 (stat) \pm
0.07(syst).

23
The categories of this paper are: solv-int
3
The categories of this paper are: physics
5
The categories of this paper are: gr-qc
18
The categories of this paper are: econ
4
The categories of this paper are: cond-mat
12
The categories of this paper are: nucl-th
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The categories of this paper are: supr-con
16
The categories of this paper are: stat
17
The categories of this paper are: q-fin
6
The categories of this paper are: astro-ph
7
The categories of this paper are: hep-th
34
The categories of this paper are: chem-ph
9
The categories of this paper are: nlin
32
The categories of this paper are: atom-ph
10
The categories of this paper are: q-bio
0
The categories of this paper are: hep-ph