Measurement of CP asymmetries in $D^0 \rightarrow hh$ decays

Abstract

The latest measurements of the individual time-integrated CP asymmetry in the Cabibbo-suppressed decays $D^0\rightarrow hh$ decays are presented. The results are based on $pp$ collision data, corresponding to an integrated luminosity of $3 fb^{-1}$, collected with the LHCb detector at centre-of-mass energies of 7 and 8 TeV. A combination of the asymmetries using both prompt and secondary charm decays is presented $A_{CP}(K^-K^+) = (0.04 \pm 0.12(stat) \pm 0.10(syst))%$; $A_{CP}(\pi^-\pi^+) = (0.07 \pm 0.14(stat) \pm 0.11(syst))$. These are the most precise measurements from a single experiment. The result for $A_{CP}(K^-K^+)$ is the most precise determination of a time-integrated CP asymmetry in the charm sector to date, and neither measurement shows evidence of CP asymmetry.