Model-independent determination of the strong-phase difference between D0 and D̅ 0→KS,L0h+h- (h=π, K) and its impact on the measurement of the CKM angle γ/ϕ3

We report the first determination of the relative strong-phase difference between D0→KS,L0K+K- and D̅ 0→KS,L0K+K-. In addition, we present updated measurements of the relative strong-phase difference between D0→KS,L0π+π- and D̅ 0→KS,L0π+π-. Both measurements exploit the quantum coherence between a pair of D0 and D̅ 0 mesons produced from ψ(3770) decays. The strong-phase differences measured are important for determining the Cabibbo-Kobayashi-Maskawa angle γ/ϕ3 in B-→K-D˜0 decays, where D˜0 is a D0 or D̅ 0 meson decaying to KS0h+h- (h=π, K), in a manner independent of the model assumed to describe the D0→KS0h+h- decay. Using our results, the uncertainty in γ/ϕ3 due to the error on the strong-phase difference is expected to be between 1.7° and 3.9° for an analysis using B-→K-D˜0, D˜0→KS0π+π- decays, and between 3.2° and 3.9° for an analysis based on B-→K-D˜0, D˜0→KS0K+K- decays. A measurement is also presented of the CP-odd fraction, F-, of the decay D0→KS0K+K- in the region of the ϕ→K+K- resonance. We find that in a region within 0.01  GeV2/c4 of the nominal ϕ mass squared F->0.91 at the 90% confidence level.