Evidence for ${B}^{0}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{0}{\ensuremath{\pi}}^{0}$

Evidence for $B^{0} \to π^{0} π^{0}$

S. H. Lee et al. (Belle Collaboration)

Phys. Rev. Lett. 91, 261801 – Published 24 December 2003

Abstract

We report evidence for the decay $B^{0} \to π^{0} π^{0}$ . The analysis is based on a data sample of ${152 \times 10}^{6}$ $B \bar{B}$ pairs collected at the $Υ (4 S)$ resonance with the Belle detector at the KEKB $e^{+} e^{-}$ storage ring. We detect a signal for $B^{0} \to π^{0} π^{0}$ with a significance of 3.4 standard deviations, and measure the branching fraction to be $[1.7 \pm 0.6 (s t a t) \pm 0.2 (s y s t)] \times 10^{- 6}$ .