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Measurement of the Λ0b, Ξ−b and Ω−b baryon masses

Research output: Contribution to journalArticle

Original languageEnglish
Pages (from-to)182001
Number of pages1
JournalPhysical Review Letters
Volume110
Early online date5 Feb 2013
DOIs
StatePublished - 2 May 2013

Abstract

Bottom baryons decaying to a J/ψ meson and a hyperon are reconstructed using 1.0 fb−1 of data collected in 2011 with the LHCb detector. Significant Λ0b→J/ψΛ, Ξ−b→J/ψΞ− and Ω−b→J/ψΩ− signals are observed and the corresponding masses are measured to be
M(Λ0b)=5619.53±0.13(stat)±0.45(syst)MeV/c2,M(Ξ−b)=5795.8±0.9(stat)±0.4(syst)MeV/c2,M(Ω−b)=6046.0±2.2(stat)±0.5(syst)MeV/c2,
while the diffierences with respect to the Λ0b mass are
M(Ξ−b)−M(Λ0b)=176.2±0.9(stat)±0.1(syst)MeV/c2,M(Ω−b)−M(Λ0b)=426.4±2.2(stat)±0.4(syst)MeV/c2.
These are the most precise mass measurements of the Λ0b, Ξ−b and Ω−b baryons to date. Averaging the above Λ0b mass measurement with that published by LHCb using 35 pb−1 of data collected in 2010 yields M(Λ0b)=5619.44±0.13(stat)±0.38(syst) MeV/c2.

ID: 8093137