Evidence for B+→J/ψpΛ¯ and Search for B0→J/ψpp¯

We have performed a search for the decays B⁺→J/ψpΛ¯ and B⁰→J/ψpp¯ in a data set of (88.9±1.0)×10⁶ ϒ(4S) decays collected by the BABAR experiment at the PEP-II e⁺e^- storage ring at the Stanford Linear Accelerator Center. Four charged B candidates have been observed with an expected background of 0.21±0.14 events. The corresponding branching fraction is (12⁺⁹_-6)×10^-6, where statistical and systematic uncertainties have been combined. The result can be interpreted as a 90% confidence level (C.L.) upper limit of 26×10^-6. We also find one B⁰ candidate, with an expected background of 0.64±0.17 events, implying a 90% C.L. upper limit of 1.9×10^-6.