Search for exclusive charmless hadronic<i>B</i>decays

We have searched for two-body charmless hadronic decays of B mesons. Final states include \ensuremath{\pi}\ensuremath{\pi}, K\ensuremath{\pi}, and KK with both charged and neutral kaons and pions: \ensuremath{\pi}\ensuremath{\rho}, K\ensuremath{\rho}, and ${\mathit{K}}^{\mathrm{*}}$\ensuremath{\pi}; and K\ensuremath{\varphi}, ${\mathit{K}}^{\mathrm{*}}$\ensuremath{\varphi}, and \ensuremath{\varphi}\ensuremath{\varphi}. The data used in this analysis consist of 2.6\ifmmode\times\else\texttimes\fi{}${10}^{6}$ BB\ifmmode\bar\else\textasciimacron\fi{} pairs produced at the \ensuremath{\Upsilon}(4S) taken with the CLEO II detector at the Cornell Electron Storage Ring (CESR). We measure the branching fraction of the sum of ${\mathit{B}}^{0}$\ensuremath{\rightarrow}${\mathrm{\ensuremath{\pi}}}^{+}$${\mathrm{\ensuremath{\pi}}}^{\mathrm{\ensuremath{-}}}$ and ${\mathit{B}}^{0}$\ensuremath{\rightarrow}${\mathit{K}}^{+}$${\mathrm{\ensuremath{\pi}}}^{\mathrm{\ensuremath{-}}}$ to be (1.${8}_{\mathrm{\ensuremath{-}}0.5\mathrm{\ensuremath{-}}0.3}^{+0.6+0.2}$\ifmmode\pm\else\textpm\fi{}0.2)\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}5}$. In addition, we place upper limts on individual branching fractions in the range from ${10}^{\mathrm{\ensuremath{-}}4}$ to ${10}^{\mathrm{\ensuremath{-}}6}$. \textcopyright{} 1996 The American Physical Society.