Bound states of multiple top quarks due to Higgs exchange

Froggatt, Nielsen et al. [C.D. Froggatt, L.V. Laperashvili, R.B. Nevzorov, H.B. Nielsen, and C.R. Das, arXiv:0804.4506; C.D. Froggatt, H.B. Nielsen, and L.V. Laperashvili, Int. J. Mod. Phys. A IMPAEF 0217-751X 20, 1268 (2005); C.D. Froggatt and H.B. Nielsen, Surv. High Energy Phys. SHEPDB 0142-2413 18, 55 (2003).] suggested that the Higgs boson exchange between top quarks produces enough attraction to generate their multiple bound states. Furthermore they claimed that the system of 6 top and 6 antitop quarks is bound so strongly that the binding energy nearly compensates the masses of t quarks, making it very light. We calculated the energy of such states more accurately, variationally and by self-consistent mean-field approximation, and found that these states are weakly bound for a massless Higgs boson and unbound taking into account its mass.