Measurement of b-baryons with the CDF II detector

We report the observation of new bottom baryon states. The most recent result is the observation of the baryon Ξ_b⁻ through the decay Ξ_b⁻ → J/ψΞ⁻. The significance of the signal corresponds to 7.7σ and the Ξ_b⁻ mass is measured to be 5792.9 ± 2.5(stat.) ± 1.7(syst.) MeV/c². In addition we observe four resonances in the Λ_b⁰π± spectra, consistent with the bottom baryons Σ_b^(*)±. All observations are in agreement with theoretical expectations.