Observation of the Doubly Strange b Baryon {omega}{sub b}{sup -}

We report the observation of the doubly strange b baryon {omega}{sub b}{sup -} in the decay channel {omega}{sub b}{sup -}{yields}J/{psi}{omega}{sup -}, with J/{psi}{yields}{mu}{sup +}{mu}{sup -} and {omega}{sup -}{yields}{lambda}K{sup -}{yields}(p{pi}{sup -})K{sup -}, in pp collisions at {radical}(s)=1.96 TeV. Using approximately 1.3 fb{sup -1} of data collected with the D0 detector at the Fermilab Tevatron Collider, we observe 17.8{+-}4.9(stat){+-}0.8(syst) {omega}{sub b}{sup -} signal events at a mass of 6.165{+-}0.010(stat){+-}0.013(syst) GeV. The significance of the observed signal is 5.4{sigma}, corresponding to a probability of 6.7x10{sup -8} of it arising from a background fluctuation.