Precision measurement of the $D^{*0}$ decay branching fractions

TL;DR

This paper reports a precise measurement of the decay branching fractions of the $D^{*0}$ meson into $D^0 o ext{pi}^0$ and $D^0 o ext{gamma}$, significantly improving the accuracy over previous results.

Contribution

The study provides the most precise measurements to date of $D^{*0}$ decay branching fractions, refining previous world averages by a factor of three.

Findings

Branching fraction for $D^{*0} o D^0 ext{pi}^0$ is 65.5%

Branching fraction for $D^{*0} o D^0 ext{gamma}$ is 34.5%

Ratio of branching fractions is 1.90

Abstract

Using 482 pb$^{-1}$ of data taken at $\sqrt{s}=4.009$ GeV, we measure the branching fractions of the decays of $D^{*0}$ into $D^0\pi^0$ and $D^0\gamma$ to be $\BR(D^{*0} \to D^0\pi^0)=(65.5\pm 0.8\pm 0.5)%$ and $\BR(D^{*0} \to D^0\gamma)=(34.5\pm 0.8\pm 0.5)%$ respectively, by assuming that the $D^{*0}$ decays only into these two modes. The ratio of the two branching fractions is $\BR(D^{*0} \to D^0\pi^0)/\BR(D^{*0} \to D^0\gamma) =1.90\pm 0.07\pm 0.05$, which is independent of the assumption made above. The first uncertainties are statistical and the second ones systematic. The precision is improved by a factor of three compared to the present world average values.