2025/04/30 by LHCb collaboration, Aaij, R., Abdelmotteleb, A. S. W. +1131 · 2 voices
#FOS: Physical sciences #High Energy Physics - Experiment (hep-ex)
paper · doi:10.48550/arxiv.2504.21269
A study of the charmless baryonic decays B0(s) → K0 p p is presented, where B0(s) denotes either a B0 or a B0s meson. The analysis is based on proton-proton collision data collected by the LHCb experiment at centre-of-mass energies of 7, 8, and 13~Tev, corresponding to an integrated luminosity of 9~fb-1. The decay B0s → K0 p p is observed for the first time, with a measured branching fraction of (9.14 ± 1.69 ± 0.90 ± 0.33 ± 0.20) × 10-7 and a significance of 5.6σ. The uncertainties respectively account for statistical and systematic contributions, the precision of the branching fraction of the normalisation channel B0 → K0 π+ π- and the fragmentation fraction ratio fs/fd. The branching fraction determined for B0 → K0 p p is (2.82 ± 0.08 ± 0.12 ± 0.10) × 10-6, which is the most precise measurement to date.