ISSN - 03702693, Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, 2014, vol. 734, p. 227-233
Measurement of the D→K -π + strong phase difference in ψ(3770)→D0D-0
We study D0D-0 pairs produced in e +e - collisions at s=3.773GeV using a data sample of 2.92 fb-1 collected with the BESIII detector. We measured the asymmetry AKπCP of the branching fractions of D→K -π + in CP-odd and CP-even eigenstates to be (12.7 ± 1.3 ± 0.7) × 10 -2. AKπCP can be used to extract the strong phase difference δKπ between the doubly Cabibbo-suppressed process D-0→K-π+ and the Cabibbo-favored process D0→K -π +. Using world-average values of external parameters, we obtain cosδKπ = 1.02 ± 0.11 ± 0.06 ± 0.01. Here, the first and second uncertainties are statistical and systematic, respectively, while the third uncertainty arises from the external parameters. This is the most precise measurement of δKπ to date. © 2014 The Authors.