We report on a measurement of CP-violating asymmetries (ACP)
in the Cabibbo-suppressed D0→π+π- and D0→K+K- decays reconstructed
in a data sample corresponding to 5.9 fb-1 of integrated luminosity
collected by the upgraded Collider Detector at Fermilab. We use the
strong decay D*+→D0π+ to identify the flavor of the charmed meson
at production and exploit CP-conserving strong cc̅ pair production in
pp̅ collisions. High-statistics samples of Cabibbo-favored D0→K-π+
decays with and without a D*± tag are used to correct for instrumental
effects and significantly reduce systematic uncertainties. We
measure ACP(D0→π+π-)=(+0.22±0.24(stat)±0.11(syst))% and
ACP(D0→K+K-)=(-0.24±0.22(stat)±0.09(syst))%, in agreement with CP
conservation. These are the most precise determinations from a single
experiment to date. Under the assumption of negligible direct CP violation
in D0→π+π- and D0→K+K- decays, the results provide an upper limit
to the CP-violating asymmetry in D0 mixing, |ACPind(D0)|<0.13% at
the 90% confidence level.
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Updated: Friday, 2012 January 27 15:26:06 CST automatically from input from "Stephanie A. Schuler"