Abstract
The first measurements of the coherence factor and the average strong-phase difference in decays are reported. These parameters can be used to improve the determination of the unitary triangle angle in decays, where is either a or a 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 pairs produced in collisions at the resonance. The measured values are and for an unrestricted kinematic region and and for a region where the combined invariant mass is within of the 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 resonance. The branching ratio is determined to be , which is more precise than previous measurements.
3 More- Received 16 March 2012
DOI:https://doi.org/10.1103/PhysRevD.85.092016
© 2012 American Physical Society