Orateur
M.
Andreas Weiden
(University Zurich)
Description
A search for direct $CP$ violation in the up-type quark sector is performed using pp collision data, corresponding to an integrated luminosity of 3fb$^{-1}$, collected using the LHCb detector at centre-of-mass energies of 7 and 8 TeV.
The difference between the $CP$ asymmetries in $D^0 \to K^-K^+$ and $D^0 \to \pi^-\pi^+$ decays, $\Delta A_{CP} \equiv A_{CP}(K^-K^+) - A_{CP}(\pi^-\pi^+)$ is a measurement of direct $CP$-violation in the charm sector. This measurement, which has been performed multiple times at different experiments with ever increasing data samples, has triggered a lot of interest in recent years. After the analysis of the first 0.6/fb of data taken in 2011 by LHCb, the world average of $\Delta A_{CP}$ was showing a $3.5\sigma$ deviation from the naive SM expectation of zero. A confirmation of a $CP$ asymmetry of this magnitude would likely indicate contributions from physics beyond the Standard model.
A new measurement of $\Delta A_{CP}$ using all prompt $D^0$ decays during Run 1 was performed by LHCb. A value of $\Delta A_{CP} = [-0.10 \pm 0.08 \text{ (stat)} \pm 0.03 \text{ (syst)}]\%,$ was determined.
Summary
The results from the latest measurement of $\Delta A_{CP}$ using all prompt $D^0$ decays recorded by LHCb during Run 1 is presented.
Auteur principal
M.
Andreas Weiden
(University Zurich)
