2008/08/31 by The Belle Collaboration, C.-C. Chiang, I. Adachi +96 · 1 citation
Engineering · Physics and Astronomy · #Particle Accelerators and Free-Electron Lasers #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #hep-ex
paper · pdf · doi:10.1103/physrevd.78.111102
published as Phys.Rev.D78:111102,2008 · 6 pages, 2 figures. Submitted to PRD(RC)
arxiv created 2008/11/21 · openalex publication_date 2008/12/03 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
We report on a search for the decay B0\ensuremath→\ensuremathρ0\ensuremathρ0 and other charmless modes with a \ensuremathπ+\ensuremathπ^\ensuremath-\ensuremathπ+\ensuremathπ^\ensuremath- final state, including B0\ensuremath→\ensuremathρ0\ensuremathπ+\ensuremathπ^\ensuremath-, nonresonant B0\ensuremath→4\ensuremathπ^\ifmmode±\else\textpm\fi, B0\ensuremath→\ensuremathρ0f0(980), B0\ensuremath→f0(980)f0(980) and B0\ensuremath→f0(980)\ensuremathπ+\ensuremathπ^\ensuremath-. These results are obtained from a data sample containing 657\ifmmode×\else\texttimes\fi106 BB pairs collected with the Belle detector at the KEKB asymmetric-energy e+e^\ensuremath- collider. We set an upper limit on B(B0\ensuremath→\ensuremathρ0\ensuremathρ0) of 1.0\ifmmode×\else\texttimes\fi10^\ensuremath-6 at the 90% confidence level (C.L.). From our B0\ensuremath→\ensuremathρ0\ensuremathρ0 measurement and an isospin analysis, we determine the Cabibbo-Kobayashi-Maskawa phase \ensuremathφ2 to be 91.7\ifmmode±\else\textpm\fi14.9 degrees. We find excesses in B0\ensuremath→\ensuremathρ0\ensuremathπ+\ensuremathπ^\ensuremath- and nonresonant B0\ensuremath→4\ensuremathπ^\ifmmode±\else\textpm\fi with 1.3\ensuremathσ and 2.5\ensuremathσ significance, respectively. The corresponding branching fractions are less than 12.0\ifmmode×\else\texttimes\fi10^\ensuremath-6 and 19.3\ifmmode×\else\texttimes\fi10^\ensuremath-6 at the 90% C.L. In addition, we set 90% C.L. upper limits as follows: B(B0\ensuremath→\ensuremathρ0f0(980))<0.3\ifmmode×\else\texttimes\fi10^\ensuremath-6, B(B0\ensuremath→f0(980)f0(980))<0.1\ifmmode×\else\texttimes\fi10^\ensuremath-6, and B(B0\ensuremath→f0(980)\ensuremathπ+\ensuremathπ^\ensuremath-)<3.8\ifmmode×\else\texttimes\fi10^\ensuremath-6.