New determination of the D0→K−π+π0D0→K−π+π0 and D0→K−π+π+π−D0→K−π+π+π− coherence factors and average strong-phase differences

Measurements of the coherence factors (RKππ0RKππ0 and RK3πRK3π) and the average strong-phase differences (δDKππ0 and δDK3π) for the decays D0→K−π+π0D0→K−π+π0 and D0→K−π+π+π−D0→K−π+π+π− are presented. These parameters are important inputs to the determination of the unitarity triangle angle γ   in B∓→DK∓B∓→DK∓ decays, where D   designates a D0D0 or D¯0 meson decaying to a common final state. The measurements are made using quantum correlated DD¯ decays collected by the CLEO-c experiment at the ψ(3770)ψ(3770) resonance, and augment a previously published analysis by the inclusion of new events in which the signal decay is tagged by the mode D→KS0π+π−. The measurements also benefit from improved knowledge of external inputs, namely the D0D¯0 mixing parameters, rDKπ and several D  -meson branching fractions. The measured values are RKππ0=0.82±0.07RKππ0=0.82±0.07, δDKππ0=(164−14+20)°, RK3π=0.32−0.28+0.20 and δDK3π=(225−78+21)°. Consideration is given to how these measurements can be improved further by using the larger quantum-correlated data set collected by BESIII.