Measurement of Branching Fractions and Resonance Contributions for B0 -> D0bar K+ pi- and Search for B0 -> D0 K+ pi- Decays

TL;DR

This paper reports precise measurements of branching fractions for specific B0 meson decays involving D0, K+, and pi- particles, including resonance contributions and a search for suppressed decay modes, using a large dataset from the BaBar experiment.

Contribution

It provides new measurements of branching fractions and resonance contributions for B0 decays, including the first observation of certain decay channels and an upper limit on suppressed modes.

Findings

Measured ${ m BF}(B^0 o ar{D}^0 K^+ ext{pi}^-)$ as (88 ± 15 ± 9)×10^{-6}

Observed contributions from $B^0 o ar{D}^0 K^*(892)^0$ and $B^0 o D_2^*(2460)^- K^+$

Set an upper limit of 19×10^{-6} at 90% CL for $B^0 o D^0 K^+ ext{pi}^-$

Abstract

Using 226 million $\Upsilon(4S)\to B\bar{B}$ events collected with the BaBar detector at the PEP-II $e^+e^-$ storage ring at the Stanford Linear Accelerator Center, we measure the branching fraction for $B^0\to \bar{D}^0 K^+\pi^-$, excluding $B^0\to D^{*-} K^+$ to be $ {\cal B}(B^0\to \bar{D}^0 K^+\pi^-) = (88 \pm 15 \pm 9)\times 10^{-6} . $ We observe $B^0\to \bar{D}^0 K^*(892)^0$ and $B^0\to D_2^*(2460)^- K^+$ contributions. The ratio of branching fractions ${\cal B}(B^0\to D^{*-}K^+)/{\cal B}(B^0\to D^{*-}\pi^+) = (7.76\pm 0.34 \pm 0.29)%$ is measured separately. The branching fraction for the suppressed mode $B^0\to D^0 K^+\pi^-$ is $ {\cal B}(B^0\to D^0 K^+\pi^-) < 19 \times 10^{-6} $ at the 90% confidence level.