Observation of the Decay B 0 → π 0 π 0
Abstract
We present an observation of the decay
B
0
→
π
0
π
0
based on a sample of 124 million
B
B
¯
pairs recorded by the BABAR detector at the PEP-II asymmetric-energy
B
Factory at SLAC. We observe
46±13±3
events, where the first error is statistical and the second is systematic, corresponding to a significance of 4.2 standard deviations including systematic uncertainties. We measure the branching fraction $\BR(B^{0} \to \pi^{0} \pi^{0}) = (2.1 \pm 0.6 \pm 0.3) \times 10^{-6}$, averaged over
B
0
and
B
¯
0
decays.