2004/07/31 by BaBar Collaboration, R. Barate, B. Aubert +98 · 7 citations
Physics and Astronomy · #Neutrino Physics Research #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #hep-ex
paper · pdf · doi:10.1103/physrevlett.93.131801
published as Phys.Rev.Lett.93:131801,2004 · PRL version
openalex publication_date 2004/09/20 · arxiv created 2005/01/25 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/04
We present a measurement of the direct CP violating asymmetry in the decay B0\ensuremath→K+\ensuremathπ^\ensuremath- using a data sample of 227\ifmmode×\else\texttimes\fi106 \ensuremathΥ(4S)\ensuremath→BB decays collected with the BABAR detector at the PEP-II asymmetric-energy e+e^\ensuremath- collider at SLAC. We observe a total signal yield of n_K^\ensuremath-\ensuremathπ++n_K+\ensuremathπ^\ensuremath-=1606\ifmmode±\else\textpm\fi51 decays and measure the asymmetry (n_K^\ensuremath-\ensuremathπ+\ensuremath-n_K+\ensuremathπ^\ensuremath-)/(n_K^\ensuremath-\ensuremathπ++n_K+\ensuremathπ^\ensuremath-)=\ensuremath-0.133\ifmmode±\else\textpm\fi0.030(stat)\ifmmode±\else\textpm\fi0.009(syst). The probability of observing such an asymmetry in the absence of direct CP violation is 1.3\ifmmode×\else\texttimes\fi10^\ensuremath-5, corresponding to 4.2 standard deviations.