A Study of the Decay D0->K+pi-

TL;DR

This paper reports the observation of the rare decay D0->K+pi- in photoproduced charm mesons, providing data to study D0 mixing and doubly Cabibbo suppressed decay parameters.

Contribution

First observation of the D0->K+pi- decay in photoproduction, linking decay ratio measurements to D0 mixing and suppression parameters.

Findings

Observed 149±31 D0->K+pi- decay events.

Measured decay ratio of (0.404±0.085±0.025)% between D0->K+pi- and D0->K-pi+.

Provided data to relate D0 mixing with doubly Cabibbo suppressed decay parameters.

Abstract

Using a large sample of photoproduced charm mesons from the FOCUS experiment at Fermilab (FNAL-E831), we observe the decay $D^0\to K^+\pi^-$ with a signal yield of $149\pm31$ events compared to a similarly cut sample consisting of $36760 \pm 195$ $D^0\to K^-\pi^+$ events. We use the observed ratio of $D^0\to K^+\pi^-$ to $D^0\to K^-\pi^+$ $(0.404\pm 0.085\pm 0.025)%$ to obtain a relationship between the $D^0$ mixing and doubly Cabibbo suppressed decay parameters.