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

B. Aubert
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Abstract

We present a 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 with the BaBar detector at the PEP-II asymmetric-energy $e^+e^-$ storage ring. The result of this analysis is $\mathcal{B}$($B^0\to J/ψπ^+π^-$) = (4.6 $\pm$ 0.7 $\pm$ 0.6)$\times 10^{-5}$, where the first error is statistical and the second is systematic. In addition we measure $\mathcal{B}(B^0\to J/ψρ^0) = (1.6 \pm 0.6 \pm 0.4 )\times 10^{-5}$.

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B. Aubert. 2002-09-07. A Measurement of the B0 -> J/psi pi+pi- Branching Fraction. https://doi.org/10.1103/physrevlett.90.091801

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