Diquark masses from lattice QCD

We present first results for diquark masses calculated in Landau gauge on the lattice. These masses as well as quark and baryon masses have been extracted from the long distance behavior of the correlation functions. We find that the ordering of the diquark spectrum with spin 0 and 1 states in color anti-triplet and sextet channels is in accordance with instanton motivated interaction models. We observe an attractive interaction for color anti-triplet states with a splitting between spin 0 and spin 1 diquarks that can account for the mass splitting between the nucleon and the delta. Our calculation provides no evidence for a deeply bound diquark state.