Measurement of Branching Fractions and Charge Asymmetries in B+ --> rho+pi0 and B+ -->rho0pi+ Decays, and Search for B0 --> rho0pi0

TL;DR

This paper reports measurements of branching fractions and charge asymmetries in specific B-meson decays involving rho and pion mesons, using data from the BaBar detector, providing insights into CP violation and decay dynamics.

Contribution

First measurements of branching fractions and charge asymmetries for B+ decays to rho+pi0 and rho0pi+; set upper limit for B0 to rho0pi0 decay.

Findings

Branching fraction for B+ to rho+pi0: (10.9 ± 1.9 ± 1.9)×10^{-6}

Branching fraction for B+ to rho0pi+: (9.5 ± 1.1 ± 0.8)×10^{-6}

Charge asymmetry for B+ to rho+pi0: 0.24 ± 0.16 ± 0.06

Abstract

We present measurements of branching fractions and charge asymmetries in $B$-meson decays to $\rho^+ \pi^{0}$, $\rho^{0}\pi^+$ and $\rho^0\pi^0$. The data sample comprises $89 \times 10^6$ $\Upsilon(4S) \to B\bar{B}$ decays collected with the $BaBar$ detector at the PEP-II asymmetric-energy $B$ Factory at SLAC. We find the charge-averaged branching fractions ${\cal B}(B^{+}\to \rho^{+}\pi^0) = (10.9 \pm 1.9{\rm (stat)} \pm 1.9{\rm (syst)})\times 10^{-6}$ and ${\cal B}(B^{+} \to \rho^0 \pi^{+}) = (9.5 \pm 1.1{\rm (stat)} \pm 0.8{\rm (syst)}) \times 10^{-6}$, and we set a 90% confidence-level upper limit ${\cal B}(B^0 \to \rho^0\pi^0) < 2.9 \times 10^{-6}$. We measure the charge asymmetries $A_{CP}^{\rho^{+}\pi^0} = 0.24 \pm 0.16 \pm 0.06$ and $A_{CP}^{\rho^0\pi^{+}} = -0.19 \pm 0.11 \pm 0.02$.