Improved Measurements of Color-Suppressed Decays B0bar -> D0 pi0, D0 eta, D0 omega, D*0 pi0, D*0 eta and D*0 omega

TL;DR

This paper reports improved measurements of branching fractions for color-suppressed B0 decays to D0 or D*0 with neutral light mesons, revealing higher values than theoretical expectations based on naive factorization.

Contribution

It provides more precise experimental data on B0 decay branching fractions, challenging existing theoretical models and enhancing understanding of color-suppressed decay mechanisms.

Findings

Measured branching fractions range from 1.4 to 2.4 x 10^{-4}

Results are significantly higher than naive factorization predictions

Data set is seven times larger than previous measurements

Abstract

We present improved measurements of the branching fractions of the color-suppressed decays $\bar{B}^0 \to D^{(*)0} h^{0}$ where $h^{0}$ represents a light neutral meson $\pi^{0}$, $\eta$ or $\omega$. The measurements are based on a data sample of 140 $fb^{-1}$, collected at the $\Upsilon(4S)$ resonance with the Belle detector at the KEKB energy-asymmetric $e^+e^-$ collider, corresponding to seven times the luminosity of the previous Belle measurements. All the measured branching fractions fall in the range 1.4-2.4 $\times 10^{-4}$, which is significantly higher than theoretical predictions based on naive factorization.