Aubert, B (reprint author), Lab Annecy Le Vieux Phys Particules, F-74941 Annecy Le Vieux, France.
We analyze 230.4 fb(-1) of data collected with the BABAR detector at the PEP-II e(+)e(-) collider at SLAC to search for evidence of D-0-(D) over bar (0) mixing using regions of phase space in the decay D-0 -> K+pi(-)pi(0). We measure the time-integrated mixing rate R-M=(0.023(-0.014)(+0.018)(stat.)+/- 0.004(syst.))%, and R-M < 0.054% at the 95% confidence level, assuming CP invariance. The data are consistent with no mixing at the 4.5% confidence level. We also measure the branching ratio for D-0 -> K+pi(-)pi(0) relative to D-0 -> K-pi(+)pi(0) to be (0.214 +/- 0.008(stat.)+/- 0.008(syst.))%.