Observation of the Doubly Strange b Baryon Omega-_b with the D0 Detector

Abstract

CINVESTAV Mexico E-mail: jjesus@fnal.govWe report the first observation of the doubly strange b-baryon Ω − b in the decay channelUsing approximately 1.3 fb −1 of data collected with the DØ 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/c 2 with a significance of 5.4 σ , meaning that the probability of the signal coming from a fluctuation in the background is 6.7 × 10 −8 .