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تسجيل مستخدم جديدMeasurements of indirect CP asymmetries in $D^0to K^-K^+$ and $D^0topi^-pi^+$ decays
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A study of indirect CP violation in $D^0$ mesons through the determination of the parameter $A_Gamma$ is presented using a data sample of $pp$ collisions, corresponding to an integrated luminosity of 1.0 fb$^{-1}$, collected with the LHCb detector and recorded at the centre-of-mass energy of 7 TeV at the LHC. The parameter $A_Gamma$ is the asymmetry of the effective lifetimes measured in decays of $D^0$ and $bar{D}^0$ mesons to the CP eigenstates $K^-K^+$ and $pi^-pi^+$. Fits to the data sample yield $A_Gamma(KK)=(-0.35pm0.62pm0.12)times 10^{-3}$ and $A_Gamma(pipi)=(0.33pm1.06pm0.14)times 10^{-3}$, where the first uncertainties are statistical and the second systematic. The results represent the worlds best measurements of these quantities. They show no difference in $A_Gamma$ between the two final states and no indication of CP violation.
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Time-dependent $CP$ asymmetries in the decay rates of the singly Cabibbo-suppressed decays $D^0rightarrow K^-K^+$ and $D^0rightarrow pi^-pi^+$ are measured in $pp$ collision data corresponding to an integrated luminosity of 3.0 fb$^{-1}$ collected by
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