B Decays to Two Charmless Pseudoscalar Mesons at CLEO

Abstract

Using 3.3 Million $B\bar{B}$ pairs accumulated with the CLEO detector CLEO has measured $\mathcal{B}(B^0\to K^{+}{\pi }^{-})=(1.5_{-0.4}^{+0.5}\pm 0.1\pm 0.1)\times 10^{-5}$, $\mathcal{B}(B^{+}\to K^0{\pi }^{+})=(2.3_{-1.0}^{+1.1}\pm 0.2\pm 0.2)\times 10^{-5}$, and $\mathcal{B}(B^{+}\to {\eta }^{{}^{\prime }}{K}^{+})=(7.8_{-2.2}^{+2.7}\pm 1.0)\times 10^{-5}$. These constitute the first observations of exclusive $B$\ decays to charmless hadronic final states. Furthermore, a measurement of $\mathcal{B}(B^{+}\to h^{+}{\pi }^0)=(1.6_{-0.5-0.2}^{+0.6+0.3}\pm 0.1)\times 10^{-5}$, as well as upper limits on various other $B$ decays to two charmless pseudoscalar mesons are presented. In particular, an upper limit of $\mathcal{B}(B^0\to {\pi }^{+}{\pi }^{-})<1.5\times 10^{-5}$ @ 90%C.L. is placed. All of these results are still preliminary, and averaging over charge conjugate modes is always implied.

6 pages, LaTex