PNNL

Abstract

We present a search for the decays of B0 mesons into a nal state containing a baryon and missing energy. These results are obtained from a 711 fb??1 data sample that contains 772106 BB pairs and was collected near the ?(4S) resonance with the Belle detector at the KEKB asymmetric energy e+e?? collider. We use events in which one B is fully reconstructed in a hadronic decay mode and require the remainder of the event to consist of only a single ?. No evidence for these decays is observed and we set upper limits on the branching fractions at 90% confidence level. This measurement provides the world's currently most restrictive limits, with implications for baryogenesis and dark matter production.