Study of B+→p¯nπ0

We search for the tree-diagram dominated process B+→p¯nπ0, using a data sample of 772×106B¯B pairs collected at the Υ(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e− collider. This is the first search with the Belle detector for a decay mode including an antineutron. No significant signal is observed and a 90% credible upper limit on the branching fraction is set at 6.3×10−6.