Search for charmless two-body baryonic decays of [Formula Presented] mesons

We report the results of a search for the rare baryonic decays B0→pp̄, ΛΛ, and B+→pΛ. The analysis is based on a data set of 31.7×106 BB̄ events collected by the Belle detector at the KEKB e+e- collider. No statistically significant signals are found, and we set branching fraction upper limits B(B0→pp̄)<1.2×10-6, B(B0→ΛΛ)<1.0×106, and B(B+→pΛ)<2.2×10-6 at the confidence level.