Beautiful Baryons from Lattice QCD

Abstract

We perform a lattice study of heavy baryons, containing one ($Λ_b$) or two $b$-quarks ($Ξ_b$). Using the quenched approximation we obtain for the mass of $Λ_b$ $$ M_{Λ_b}= 5.728 \pm 0.144 \pm 0.018 {\rm GeV}.$$ The mass splitting between the $Λ_b$ and the B-meson is found to increase by about 20\% if the light quark mass is varied from the chiral limit to the strange quark mass.