The first measurements of the coherence factor RKS0Kπ and the average strong-phase difference δDKS0Kπ in D0→KS0K ∓π± decays are reported. These parameters can be used to improve the determination of the unitary triangle angle γ in B-→D∼K- decays, where D∼ is either a D0 or a D̄0 meson decaying to the same final state, and also in studies of charm mixing. The measurements of the coherence factor and strong-phase difference are made using quantum-correlated, fully reconstructed D0D̄0 pairs produced in e+e- collisions at the ψ(3770) resonance. The measured values are RKS0Kπ=0. 73±0.08 and δDKS0Kπ=(8.3±15.2)° for an unrestricted kinematic region and RK*K=1.00±0.16 and δDK *K=(26.5±15.8)° for a region where the combined KS0π± invariant mass is within 100MeV/c2 of the K *(892)± mass. These results indicate a significant level of coherence in the decay. In addition, isobar models are presented for the two decays, which show the dominance of the K *(892)± resonance. The branching ratio B(D0→KS0K+π-)/B(D0→KS0K -π+) is determined to be 0.592±0.044(stat) ±0.018(syst), which is more precise than previous measurements.
|Original language||English (US)|
|Journal||Physical Review D - Particles, Fields, Gravitation and Cosmology|
|State||Published - May 29 2012|