Evidence for the decay $B^0 o par{p}pi^0$

We report a search for the charmless baryonic decay $B^0to pbar{p}pi^0$ with a data sample corresponding to an integrated luminosity of 711~$rm fb^{-1}$ containing $(772pm 10)times 10^6$ $B^0bar{B}^0$ pairs. The data was collected by the Belle experiment running on the $Upsilon(4S)$ resonance at the KEKB $e^+e^-$ collider. We measure a branching fraction $mathcal{B}(B^0to pbar{p}pi^0)= (5.0pm1.8pm0.6 )times 10^{-7}$, where the first uncertainty is statistical and the second is systematic. The signal has a significance of 3.1 standard deviations and constitutes the first evidence for this decay mode. We also search for the intermediate two-body decays $B^{0}toDelta^+bar{p}$ and $B^0tobar{Delta}^-p$, and set an upper limit on the branching fraction: $mathcal{B}(B^0to Delta^+bar{p})+mathcal{B}(B^0tobar{Delta}^-p)u003c1.6times10^{-6}$ at 90% confidence level.