|Measurement of indirect CP-violating asymmetries in D0 → K+K− and D0 → π+π− decays at CDF|
A search for indirect CP violation in D0 → K+K− and D0 → π+π− decays is performed using the full Run II data set, corresponding to 9.7 fb−1 of integrated luminosity and collected by the trigger on displaced tracks.
Exploiting the strong D*+ →D0 π+ decay to identify the flavor of the neutral charmed meson at production time, we measure in each decay mode the asymmetry in several decay-time bins between the numbers of charm and anticharm decays. By fitting the yield asymmetry as a function of decay time with a linear function, we measure the amount of indirect CP violation, which is linked to the effective-lifetime asymmetry AΓ, by ACPind = −AΓ.
The analysis is described in CDF Public Note 11117.
The results do not show any sign of indirect CP violation:
AΓ(K+K−) = [-1.9 ± 1.5 (stat.) ± 0.4 (syst.)] × 10−3,
They are among the most precise measurements to date of these quantities and are compatible with those from other experiments.