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

The large number of B-c 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 Xi(cc), Xi(bb), and Xi(bc), 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(Xi(cc)) = 3627 +/- 12 MeV, M(Xi(cc)*) = 3690 +/- 12 MeV, M(Xi(bb)) = 10162 +/- 12 MeV, M(Xi(bb)*) = 10184 +/- 12 MeV, M(Xi(bc)) = 6914 +/- 13 MeV, M(Xi(bc)') = 6933 +/- 12 MeV, and M(Xi(bc)*) = 6969 +/- 14 MeV. As a byproduct, we estimate the hyperfine splitting between B-c* and B-c mesons to be 68 +/- 8 MeV. We discuss P-wave excitations, production mechanisms, decay modes, lifetimes, and prospects for detection of the doubly heavy baryons.