Measurement of the $CP$ violation parameter $A_{\Gamma}$ in $D^{0}\rightarrow K^{+}K^{-}$ and $D^{0}\rightarrow \pi^{+}\pi^{-}$ decays at LHCb.

Marino P., Morello M. J., Pajero T., Punzi G.
  Martedì 12/09   09:00 - 13:00   Aula A208   I - Fisica nucleare e subnucleare
$CP$ violation has not been observed yet in the charm sector. In recent years, the LHCb experiment has become the main player in the charm sector, thanks to the pure, huge samples of charm mesons decays that it is able to collect, allowing to approach for the first time the upper boundaries of Standard Model expectations for $CP$-violation, $O(10^{-3})$. We present the world best measurement of the $CP$-violating parameter $A_{\Gamma}$, the asymmetry between the effective decay widths of $D^{0}$ and $\bar{D}^{0}$ mesons into the $CP$-symmetric final states $K^{+}K^{-}$ and $\pi^{+}\pi^{-}$, currently the most precise probe of indirect $CP$ violation in the charm sector.