A search for CP violation in D0→K-K+ and D0→π-π+ decays is performed using pp collision data, corresponding to an integrated luminosity of 3 fb-1, collected using the LHCb detector at center-of-mass energies of 7 and 8 TeV. The flavor of the charm meson is inferred from the charge of the pion in D∗+→D0π+ and D∗-→D0π- decays. The difference between the CP asymmetries in D0→K-K+ and D0→π-π+ decays, ΔACP≡ACP(K-K+)-ACP(π-π+), is measured to be [-0.10±0.08(stat)±0.03(syst)]%. This is the most precise measurement of a time-integrated CP asymmetry in the charm sector from a single experiment.
Aaij, R., Abellán Beteta, C., Adeva, B., Adinolfi, M., Affolder, A., Ajaltouni, Z., … Zucchelli, S. (2016). Measurement of the Difference of Time-Integrated CP Asymmetries in D0 → K-K+ and D0 → π-π + Decays. Physical Review Letters, 116(19). https://doi.org/10.1103/PhysRevLett.116.191601