Observation of the Doubly StrangebBaryonΩb−

We report the observation of the doubly strange $b$ baryon ${\ensuremath{\Omega}}_{b}^{\ensuremath{-}}$ in the decay channel ${\ensuremath{\Omega}}_{b}^{\ensuremath{-}}\ensuremath{\rightarrow}J/\ensuremath{\psi}{\ensuremath{\Omega}}^{\ensuremath{-}}$, with $J/\ensuremath{\psi}\ensuremath{\rightarrow}{\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}}$ and ${\ensuremath{\Omega}}^{\ensuremath{-}}\ensuremath{\rightarrow}\ensuremath{\Lambda}{K}^{\ensuremath{-}}\ensuremath{\rightarrow}(p{\ensuremath{\pi}}^{\ensuremath{-}}){K}^{\ensuremath{-}}$, in $p\overline{p}$ collisions at $\sqrt{s}=1.96\text{ }\text{ }\mathrm{TeV}$. Using approximately $1.3\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ of data collected with the D0 detector at the Fermilab Tevatron Collider, we observe $17.8\ifmmode\pm\else\textpm\fi{}4.9(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}0.8(\mathrm{syst})$ ${\ensuremath{\Omega}}_{b}^{\ensuremath{-}}$ signal events at a mass of $6.165\ifmmode\pm\else\textpm\fi{}0.010(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}0.013(\mathrm{syst})\text{ }\text{ }\mathrm{GeV}$. The significance of the observed signal is $5.4\ensuremath{\sigma}$, corresponding to a probability of $6.7\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}8}$ of it arising from a background fluctuation.

Observation of the Doubly StrangebBaryonΩb− | Litlas