Study of $\bar{B^{0}} \to D^{(*)0} \pi^+ \pi^-$ Decays

TL;DR

This study measures branching fractions of specific B meson decays using Belle data, reports the first observation of a color-suppressed decay mode, and compares related decay rates.

Contribution

It provides the first measurement of the color-suppressed decay $ar{B}^0 o D^0 ho^0$ and determines branching fractions for $ar{B}^0 o D^{(*)0} ho^0 ho^0$ decays.

Findings

Branching fraction for $ar{B}^0 o D^0 ho^0$ is $(2.9 imes 10^{-4})$

First observation of $ar{B}^0 o D^0 ho^0$ decay

Ratio of branching fractions ${ m BF}(ar{B}^0 o D^0 ho^0)/{ m BF}(ar{B}^0 o D^0 ho^0)$ is 1.6 ± 0.8

Abstract

We report on a study of $\bar{B^{0}} \to D^{(*) 0} \pi^+ \pi^-$ decays using 29.1 fb$^{-1}$ of $e^{+}e^{-}$ annihilation data recorded at the $\Upsilon(4S)$ resonance with the Belle detector at the KEKB storage ring. Making no assumptions about the intermediate mechanism, the branching fractions for $\bar{B}^0 \to D^0 \pi^+ \pi^-$ and $\bar{B}^0 \to D^{* 0} \pi^+ \pi^-$ are determined to be $(8.0 \pm 0.6 \pm 1.5) \times 10^{-4} $ and $ (6.2 \pm 1.2 \pm 1.8) \times 10^{-4}$ respectively. An analysis of $\bar{B^{0}} \to D^{0} \pi^+ \pi^-$ candidates yields to the first observation of the color-suppressed hadronic decay $\bar{B}^0 \to D^0 \rho^0$ with the branching fraction $(2.9 \pm 1.0 \pm 0.4) \times 10^{-4}$. We measure the ratio of branching fractions ${\mathcal B}(\bar{B^0} \to D^0 \rho^0) / {\mathcal B}(\bar{B^0} \to D^0 \omega)$ = 1.6 $\pm$ 0.8.