Study of the Strongly Interacting Higgs Physics Model with Heavy Fermions.pdf

Study of the Strongly Interacting Higgs Physics Model with Heavy Fermions 5 9 1 2 L.V. Dung , G. Jikia , C. Roiesnel and T.N. Truong 9 1 Centre de Physique Th´eorique, n Centre National de la Recherche Scientifique, UPR A0014, u J Ecole Polytechnique, 91128 Palaiseau Cedex, France 1 2 June 1995 1 v 4 8 Abstract 3 6 We study the effect of a possible fourth heavy generation of fermions 0 on the Higgs sector of the standard model. We show, from the violation of 5 9 elastic unitarity, that the scale of strong interactions is well below 1 TeV / even with a Higgs mass as low as 500 GeV provided the fourth generation h p fermion mass is equal or larger than the Higgs mass. The diagonal Pade - p approximant method is then used to unitarize the partial wave amplitudes. e It is found that, for the fourth generation fermion masses which are com- h : parable to or larger than the Higgs mass, the Landau ghosts in the I=0 v and I=2 channels of the reconstructed amplitudes move too close to the i X physical region to be accepted. r a RR359.0695 1Permanent address: Theoretical Physics Institute, BP429 BoHo, Hanoi 10000, Vietnam. 2Permanent address: Institute for High Energy Physics, 142284, Protvino, Moscow Region, Russia. 1 1 Introduction The standard model is verified to a great accuracy by recent experiments at