Rare B, D meson decays from crystal ball

Abstract

The Crystal Ball detector at e + e − storage ring DORIS II has been used to search for rare B and D meson decays. We have looked for the radiative B meson decays of the type b → sγ. No mono-energetic γ-lines have been found in the inclusive photon spectrum from γ(4 S) decays and upper limits are obtained for radiative decays of B mesons to various strange mesons. Integrating the photon spectrum over the corresponding energy range, we get BR( B → γX) < 2.8 × 10 −3 at 90% confidence level for the mass range 892 MeV < M x < 2045 MeV. We have also searched for the decay modes D → π° π° and B → π° π°. No evidence for these Cabibbo suppressed decays was found and 90% confidence level upper limits of BR( D → π° π°) < 3.8 × 10 −3 and BR( B → π° π°) < 4.6 × 10 −4 are given.