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A Measurement of the B0 --> J/psi pi+pi- Branching Fraction

The BABAR Collaboration·B. Aubert
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Abstract

We present a preliminary measurement of the branching fraction for the decay of the neutral $B$ meson into the final state J/$ψπ^+π^-$. The data set contains approximately 56 million $B\bar{B}$ pairs produced at the $Υ(4S)$ resonance and recorded by the BaBar detector at the PEP-II $e^+e^-$ collider. The result of this analysis is $\mathcal{B}(B^0\to J/ψπ^+π^-$) = (5.0 $\pm$ 0.7 $\pm$ 0.6)$\times 10^{-5}$, where the first error is statistical and the second is systematic.

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The BABAR Collaboration, B. Aubert. 2002-03-26. A Measurement of the B0 --> J/psi pi+pi- Branching Fraction. https://arxiv.org/abs/hep-ex/0203034

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