A search for time-integrated CP violation in D0 → h?h+ decays

摘要

The preliminary results of a search for time-integrated CP violation in D0 → h?h+ (h = K, π) decays performed with 0.6 fb? of data collected by LHCb in 2011 are presented. The flavour of the charm meson is determined by the charge of the slow pion in the D*+ → D0π+ and D*? → decay chains. The difference in CP asymmetry betweenD0 → K?K+ and D0 → π?π+, ΔACP ≡ ACP(K?K+) ? ACP(π?π+), is measured to be ΔACP = |?0.82 ± 0.21(stat.) ± 0.11(syst.)|%. This differs from the hypothesis of CP conservation by 3.5σ.