Author/Authors :
H.B. Nielsen، نويسنده , , A.V Novikov، نويسنده , , V.A Novikov، نويسنده , , M.I Vysotsky، نويسنده ,
Abstract :
We consider the bounds for the values of higgs mass MH and of the mass of the extra quarks and leptons Mextra derived from the stability of vacuum and from the absence of Landau pole in Higgs potential. We find that in the case of the absence of new physics up to the GUT scale the bounds for the mass of the 4th generation are so restrictive that the negative result of CDF search for extra quarks closes the window for fourth generation. In the case of the absence of new physics up to 105 GeV we get weaker but still nontrivial bounds on MH and Mextra.