Observation of the Doubly Strange b Baryon Ω_b^-

Authors

V. M. Abazov, Joint Institute for Nuclear Research, Dubna, Russia
Kenneth A. Bloom, University of Nebraska-LincolnFollow
Gregory Snow, University of Nebraska-LincolnFollow
D0 Collaboration

Date of this Version

12-5-2008

Comments

Published in PHYSICAL REVIEW LETTERS 101, 232002 (2008). Copyright © 2008 The American Physical Society. Used by permission.

Abstract

We report the observation of the doubly strange b baryon Ω_b^- in the decay channel Ω_b^- → J/ψΩ^-, with J/ψ → μ⁺μ^- and Ω^- → ΛK^- → (pπ^-)K^-, in pp collisions at √s = 1.96 TeV. Using approximately 1.3 fb^-1 of data collected with the D0 detector at the Fermilab Tevatron Collider, we observe 17:8 ± 4.9(stat) ± 0.8(syst) Ω_b^- signal events at a mass of 6.165 ± 0.010(stat) ± 0.013(syst) GeV. The significance of the observed signal is 5.4 σ, corresponding to a probability of 6.7 x 10^-8 of it arising from a background fluctuation.