Search for D0--anti-D0 Mixing in the Decays D0 --> K+ pi- pi+ pi-

摘要

We present a search for D(sup 0)-(bar D)(sup 0) mixing in the decays D(sup 0) (yields) K(sup +)(pi)(sup -)(pi)(sup +)(pi)(sup -) using 230.4 fb(sup -1) of data collected with the BABAR detector at the PEP-II e(sup +)e(sup -) collider at SLAC. Assuming CP conservation, we measure the time-integrated mixing rate R(sub M) = (0.019(sub -0.015)(sup +0.016)(stat.) (+-) 0.002(syst.))%, and R(sub M) < 0.048% at the 95% confidence level. Using a frequentist method, we estimate that the data are consistent with no mixing at the 4.3% confidence level. We present results both with and without the assumption of CP conservation. By combining the value of R(sub M) from this analysis with that obtained from an analysis of the decays D(sup 0) (yields) K(sup +)(pi)(sup -)(pi)(sup 0), we find R(sub M) = (0.020(sub -0.010)(sup +0.011))%, where the uncertainty is statistical only. We determine the upper limit R(sub M) < 0.042% at the 95% confidence level, and we find the combined data are consistent with the no-mixing hypothesis at the 2.1% confidence level.