Results on mixing in the D0 system from BaBar

Abstract

With 12.3 fb-1 collected by the BaBar experiment in 2001, the mixing parameter y = Delta(Gamma)/(2 Gamma) is determined from the ratio of the D0 lifetimes measured in the D0 --> K- pi+ and in the D0 --> K- K+ decay modes. The preliminary result y = (-1.0 +- 2.2(stat.) +- 1.7(syst.))% is obtained. Also presented is the status of measuring the mixing parameters y and x^2 = [Delta(M)/Gamma]^2 from a simultaneous fit to the time evolution of the decay time distributions of Cabibbo-favored right-sign (D0 --> K- pi+) and doubly Cabibbo-suppressed wrong-sign (D0 --> K+ pi-) decays. The wrong-sign decay rate, R_WS = (# WS decays)/(# RS decays) = (0.38 +- 0.04(stat.) +- 0.02(syst.))% is obtained from the fit to 23 fb-1 of BaBar data taken in 2000.