Evidence for a bottom baryon resonance Λb*0 in CDF data

Abstract

Using data from proton-antiproton collisions at √s=1.96 TeV recorded by the CDF II detector at the Fermilab Tevatron, evidence for the excited resonance state Λb*0 is presented in its Λb0π -π+ decay followed by the Λb0→Λ c+π- and Λc+→pK-π+ decays. The analysis is based on a data sample corresponding to an integrated luminosity of 9.6 fb-1 collected by an online event selection based on charged-particle tracks displaced from the proton-antiproton interaction point. The significance of the observed signal is 3.5σ. The mass of the observed state is found to be 5919.22±0.76 MeV/c2 in agreement with similar findings in proton-proton collision experiments. © 2013 American Physical Society.