Observation of the Ξb−→J/ψΛK− decay

Journal article

The observation of the decay Ξ b − →J/ψΛK − is reported, using a data sample corresponding to an integrated luminosity of 3fb −1 , collected by the LHCb detector in pp collisions at centre-of-mass energies of 7 and 8TeV. The production rate of Ξ b − baryons detected in the decay Ξ b − →J/ψΛK − is measured relative to that of Λ b 0 baryons using the decay Λ b 0 →J/ψΛ. Integrated over the b-baryon transverse momentum p T < 25GeV/c and rapidity 2.0 < y < 4.5, the measured ratio is [Formula presented][Formula presented] =(4.19±0.29 (stat)±0.15 (syst))×10 −2 , where f Ξ b − and f Λ b 0 are the fragmentation fractions of b→Ξ b − and b→Λ b 0 transitions, and B represents the branching fraction of the corresponding b-baryon decay. The mass difference between Ξ b − and Λ b 0 baryons is measured to be M(Ξ b − )−M(Λ b 0 )=177.08±0.47 (stat)±0.16 (syst)MeV/c 2 .

Authors: Aaij, R; Adeva, B; Adinolfi, M; Evans, T; Gandini, P

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Elsevier
• Journal: Physics Letters B
• Volume: 772
• Pages: 265-273
• Publication date: 2017-06-01
• Acceptance date: 2017-06-11
• DOI: 10.1016/j.physletb.2017.06.045
• EISSN: 1873-2445
• ISSN: 0370-2693
• Keywords: hep-ex