Evidence for B0->pi0pi0

TL;DR

This paper presents evidence for the rare decay B0->pi0pi0, measuring its branching fraction with statistical significance, based on a large data sample collected at the KEKB collider.

Contribution

First evidence for B0->pi0pi0 decay with a measured branching fraction, using data from the Belle detector at KEKB.

Findings

Branching fraction measured as (1.7+-0.6) x 10^{-6}

Significance of 3.4 standard deviations

Evidence based on 152 million BBbar pairs

Abstract

We report evidence for the decay B0->pi0pi0. The analysis is based on a data sample of 152million BBbar pairs collected at the Upsilon(4s) resonance with the Belle detector at the KEKB e+e- storage ring. We find 25.6+9.3/-8.4(stat)+1.6/-1.4(syst) B0->pi0pi0 signal events with a significance of 3.4 standard deviations. We measure the branching fraction to be (1.7+-0.6(stat)+-0.2(syst))*10^{-6}.