Measurement of $Br(D^{0}\to K^{-}\pi^{+})$ using Partila Reconstruction of $\bar{B}\to D^{*+}X\ell^{-}\bar{\nu}$

TL;DR

This paper reports a precise measurement of the $D^0 \to K^- \pi^+$ branching fraction using partial reconstruction of $\bar{B} \to D^{*+} X \ell^- \bar{\nu}$ decays, providing valuable data for charm meson decay studies.

Contribution

The study introduces a novel partial reconstruction technique to measure the $D^0$ branching fraction with improved accuracy.

Findings

Measured $Br(D^0 \to K^- \pi^+)$ as 3.81% with statistical and systematic uncertainties.

Used data from the CLEO II detector at the Cornell Electron Storage Ring.

Achieved a more precise determination of the $D^0$ decay branching fraction.

Abstract

We present a measurement of the absolute branching fraction for $D^0 -> K^- pi^+$ using the reconstruction of the decay chain $Bbar -> D^{*+} X l^- nubar $, $D^{*+} -> D^0 pi^+$ where only the lepton and the low-momentum pion from the $D^{*+}$ are detected. With data collected by the CLEO II detector at the Cornell Electron Storage Ring, we have determined $Br(D^0 -> K^- pi^+)= [3.81 +- 0.15(stat.) +- 0.16(syst.)]%$.