Rate measurement of D0 -> K+pi-pi 0 and constraints on D-0 D(0)over-bar mixing

Abstract

We present an observation and time-integrated rate measurement of the decay D-0-->K(+)pi (-)pi (0) produced in 9 fb(-1) of e(+)e(-) collisions near the Y(4S) resonance. The signal is inconsistent with an upward fluctuation of the background by 4.9 standard deviations. We measured the time-integrated rate of D-0-->K(+)pi (-)pi (0) normalized to the rate of (D-0) over bar --> K(+)pi (-)pi (0) to be 0.0043(-0.0010)(+0.0011) (stat) +/- 0.0007 (syst).