ausblenden:
Schlagwörter:
High Energy Physics - Experiment, hep-ex
MPINP:
LHCb - Abteilung Hofmann
Zusammenfassung:
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
$A_\Gamma(KK)=(-0.35\pm0.62\pm0.12)\times 10^{-3}$ and
$A_\Gamma(\pi\pi)=(0.33\pm1.06\pm0.14)\times 10^{-3}$, where the first
uncertainties are statistical and the second systematic. The results represent
the world's best measurements of these quantities. They show no difference in
$A_\Gamma$ between the two final states and no indication of CP violation.