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

TL;DR

This paper reports a preliminary measurement of the branching fraction for the decay of the neutral B meson into J/psi and two pions, based on data from the BaBar detector, providing a key insight into B meson decay processes.

Contribution

First measurement of the B0 to J/psi pi+ pi- branching fraction using a large data set from BaBar at the Upsilon(4S) resonance.

Findings

Branching fraction measured as (5.0 ± 0.7 ± 0.6)×10^{-5}.

Data set contains approximately 56 million B B̄ pairs.

Results improve understanding of B meson decay channels.

Abstract

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