31 research outputs found
On bound states of multiple t-quarks due to Higgs exchange
Froggatt, Nielsen et al 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 anti-top 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 state are weakly bound for massless Higgs boson and unbound
with the account for its mass.Comment: 3 page
When renormalizability is not sufficient: Coulomb problem for vector bosons
The Coulomb problem for vector bosons W incorporates a known difficulty; the
boson falls on the center. In QED the fermion vacuum polarization produces a
barrier at small distances which solves the problem. In a renormalizable SU(2)
theory containing vector triplet (W^+,W^-,gamma) and a heavy fermion doublet F
with mass M the W^- falls on F^+, to distances r ~ 1/M, where M can be made
arbitrary large. To prevent the collapse the theory needs additional light
fermions, which switch the ultraviolet behavior of the theory from the
asymptotic freedom to the Landau pole. Similar situation can take place in the
Standard Model. Thus, the renormalizability of a theory is not sufficient to
guarantee a reasonable behavior at small distances for non-perturbative
problems, such as a bound state problem.Comment: Four page
Coulomb problem for vector bosons versus Standard Model
The Coulomb problem for vector bosons W(+/-) propagating in an attractive
Coulomb field incorporates a known difficulty, i.e. the total charge of the
boson localized on the Coulomb center turns out infinite. This fact contradicts
the renormalizability of the Standard model, which presumes that at small
distances all physical quantities are well defined. The paradox is shown to be
resolved by the QED vacuum polarization, which brings in a strong effective
repulsion and eradicates the infinite charge of the boson on the Coulomb
center. The effect makes the Coulomb problem for vector bosons well defined and
consistent with the Standard Model.Comment: 4 page