We report on a measurement of CP-violating asymmetries (A CP) in the Cabibbo-suppressed D0→π +π - and D0→K +K - decays reconstructed in a data sample corresponding to 5.9fb -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 cc̄ pair production in pp̄ 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 A CP(D0→π +π -)=(+0.22±0.24(stat) ±0.11(syst))% and A CP(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.
Measurement of CP-violating asymmetries in D-0 -> pi(+) pi(-) and D-0 -> K+ K- decays at CDF
Manca, G.;
2012-01-01
Abstract
We report on a measurement of CP-violating asymmetries (A CP) in the Cabibbo-suppressed D0→π +π - and D0→K +K - decays reconstructed in a data sample corresponding to 5.9fb -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 cc̄ pair production in pp̄ 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 A CP(D0→π +π -)=(+0.22±0.24(stat) ±0.11(syst))% and A CP(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.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.