D0-D0bar mixing at BABAR

Carlos CHAVEZ
2010 Proceedings of European Physical Society Europhysics Conference on High Energy Physics — PoS(EPS-HEP 2009)   unpublished
A selection of the most statistically significant measurements of D 0 -D 0 mixing performed by the BABAR experiment operating at the SLAC National Accelerator Laboratory is presented. We present evidence for charm meson (D 0 -D 0 ) mixing using a sample of 384 fb −1 of e + e − colliding beam data recorded near √ s = 10.6 GeV at the SLAC PEP-II asymmetric-energy B Factory. We measure the rate of mixing with the observable y CP = (τ Kπ /τ KK ) − 1, where τ KK and τ Kπ are respectively the mean
more » ... etimes of CP-even D 0 → K + K − and CP-mixed D 0 → K − π + decays. A new BABAR measurement of the mixing parameter y CP is presented for the first time in this conference. This new result is in good agreement with a previous BABAR measurement, obtained from a sample of D * + → D 0 π + events, where the D 0 decays to K − π + , K + K − , and π + π − , which is disjoint with the untagged D 0 events. By combining these two measurements, the no-mixing hypothesis is excluded at 4.1σ level. Finally, by measuring the wrong-sign decay D 0 → K + π − , we exclude the no-mixing hypothesis with a significance of 3.9 standard deviations.
doi:10.22323/1.084.0187 fatcat:xxaww2xksvdi7hy4naqrcc5sya