First Observation of the Cabibbo Suppressed Decay $B^{+}\to \bar{D}^{0}K^{+}$

TL;DR

This paper reports the first observation of the Cabibbo suppressed decay of the B+ meson into D0 and K+, measuring its branching fraction relative to the D0 pi+ decay, using data from the CLEO II detector.

Contribution

It provides the first experimental measurement of the suppressed decay mode of B+ mesons into D0 K+ and quantifies its branching fraction.

Findings

Branching fraction of B+ to D0 K+ is about 5.5% of B+ to D0 pi+.

Decay observed using 3.3 million B Bbar pairs at CLEO II.

Quantitative suppression factor measured with uncertainties.

Abstract

We have observed the decay of the $B^-$ meson into $D^0 K^-$, using 3.3 million $B\bar B$ pairs collected with the CLEO II detector at the Cornell Electron Storage Ring. We find the branching fractions of this decay to be suppressed relative to the decay into $D^0 \pi^-$ by $0.055 \pm 0.014 \pm 0.005$.