Search for D0-D̄0 mixing and branching-ratio measurement in the decay D0→K+π-π0

The authors present a search for D{sup 0}-{bar D}{sup 0} mixing using regions of phase space in which the rate of doubly Cabibbo-suppressed decays D{sup 0} {yields} K{sup +}{pi}{sup -}{pi}{sup 0} relative to Cabibbo-favored decays D{sup 0} {yields} K{sup -} {pi}{sup +}{pi}{sup 0} is reduced. They analyze 230.4 fb{sup -1} of data collected with the BABAR detector at the PEP-II e{sup +}e{sup -} collider at SLAC. They present results with and without the assumption of CP conservation. Assuming CP conservation, they measure the time-integrated mixing rate R{sub M} = (0.023{sub -0.014}{sup +0.018}(stat.) {+-} 0.004(syst.))%, and R{sub M} < 0.054% at the 95% confidence level. They find that the data are consistent with no mixing at the 4.5% confidence level. Considering the entire allowed phase space, they measure the branching ratio for D{sup 0} {yields} K{sup +}{pi}{sup -}{pi}{sup 0} relative to D{sup 0} {yields} K{sup -} {pi}{sup +}{pi}{sup 0} to be (0.214 {+-} 0.008(stat.) {+-} 0.008(syst.))%.