Measurement of the Branching Fractions BðB0 → p ¯pp ¯pÞ and BðB0s → p ¯pp ¯pÞ

Searches for the rare hadronic decays B0 → p ¯pp ¯p and B0s → p ¯pp ¯p are performed using proton-proton collision data recorded by the LHCb experiment and corresponding to an integrated luminosity of 9 fb−1. Significances of 9.3σ and 4.0σ, including statistical and systematic uncertainties, are obtained for the
B0 → p ¯pp ¯p and B0s → p ¯pp ¯p signals, respectively. The branching fractions are measured relative to the topologically similar normalization decays B0 → J=ψð→ p ¯pÞK0ð→ Kþπ−Þ and B0s → J=ψð→ p ¯pÞ×ϕð→ KþK−Þ. The branching fractions are measured to be BðB0 → p ¯pp ¯pÞ ¼ ð2.2 0.4 0.1 0.1Þ ×10−8 and BðB0s → p ¯pp ¯pÞ ¼ ð2.3 1.0 0.2 0.1Þ × 10−8. In these measurements, the first uncertainty is statistical, the second is systematic, and the third one is due to the external branching fraction of the normalization channel.