Baryons with two heavy quarks: Masses, production, decays, and detection

The large number of Bc mesons observed by LHCb suggests a sizable cross section for producing doubly heavy baryons in the same experiment. Motivated by this, we estimate masses of the doubly heavy J=1/2 baryons Ξcc, Ξbb, and Ξbc, and their J=3/2 hyperfine partners, using a method which accurately predicts the masses of ground-state baryons with a single heavy quark. We obtain M(Ξcc)=3627±12MeV, M(Ξcc∗)=3690±12MeV, M(Ξbb)=10162±12MeV, M(Ξbb∗)=10184±12MeV, M(Ξbc)=6914±13MeV, M(Ξ′bc)=6933±12MeV, and M(Ξbc∗)=6969±14MeV. As a byproduct, we estimate the hyperfine splitting between Bc∗ and Bc mesons to be 68±8MeV. We discuss P-wave excitations, production mechanisms, decay modes, lifetimes, and prospects for detection of the doubly heavy baryons.