2023/10/20 by LHCb Collaboration, Aaij, R., Abdelmotteleb, A. S. W. +1090
#FOS: Physical sciences #High Energy Physics - Experiment (hep-ex)
paper · doi:10.48550/arxiv.2310.13546
The Ξb0 → Ξc+ Ds- and Ξb- → Ξc0 Ds- decays are observed for the first time using proton-proton collision data collected by the LHCb experiment at a centre-of-mass energy of √(s)=13TeV, corresponding to an integrated luminosity of 5.1fb-1. The relative branching fractions times the beauty-baryon production cross-sections are measured to be R((Ξb0)/(Λb0)) ≡ (σ(Ξb0))/(σ(Λb0)) × (B(Ξb0 → Ξc+ Ds-))/(B(Λb0 → Λc0 Ds-)) =(15.8±1.1±0.6±7.7)%, R((Ξb-)/(Λb0)) ≡ (σ(Ξb-))/(σ(Λb0)) × (B(Ξb- → Ξc0 Ds-))/(B(Λb0 → Λc0 Ds-)) =(16.9±1.3±0.9±4.3)%, where the first uncertainties are statistical, the second systematic, and the third due to the uncertainties on the branching fractions of relevant charm-baryon decays. The masses of Ξb0 and Ξb- baryons are measured to be mΞb0=5791.12±0.60±0.45±0.24MeV/c2 and mΞb-=5797.02±0.63±0.49±0.29MeV/c2, where the uncertainties are statistical, systematic, and those due to charm-hadron masses, respectively.