2004/11/02 by The BABAR Collaboration, B. Aubert, R. Barate +98 · 5 citations
Physics and Astronomy · #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #hep-ex
paper · pdf · doi:10.1103/physrevd.71.032005
published as Phys.Rev.D71:032005,2005 · 31 pages, 17 postscript figures, submitted to Phys. Rev. D
arxiv created 2004/11/02 · openalex publication_date 2005/02/22 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/04
We present results on B\ensuremath→J/\ensuremathψK\ensuremathπ decays using e+e^\ensuremath-annihilation data collected with the BABAR detector at the \ensuremathΥ(4S) resonance. The detector is located at the PEP-II asymmetric-energy storage ring facility at the Stanford Linear Accelerator Center. Using approximately 88\ifmmode×\else\texttimes\fi106 BB pairs, we measure the decay amplitudes for the flavor eigenmodes and observe strong-phase differences indicative of final-state interactions with a significance of 7.6 standard deviations. We use the interference between the K\ensuremathπ S-wave and P-wave amplitudes in the region of the K*(892) to resolve the ambiguity in the determination of these strong phases. We then perform an ambiguity-free measurement of cos2\ensuremathβ using the angular and time-dependent asymmetry in B\ensuremath→J/\ensuremathψK*0(KS0\ensuremathπ0) decays. With sin2\ensuremathβ fixed at its measured value and cos2\ensuremathβ treated as an independent parameter, we find cos2\ensuremathβ=2.72_\ensuremath-0.79+0.50(stat)\ifmmode±\else\textpm\fi0.27(syst), determining the sign of cos2\ensuremathβ to be positive at 86% C.L.