Dynamical Electroweak Symmetry Breaking with a Heavy Fermion in Light of Recent LHC Results

Figure 4

The Landau pole (dotted lines) and the quasifixed point (solid lines) of the Yukawa couplings of the fourth generation fermions and the top quark. For a heavy fourth generation (left side), both the Landau singularity from one-loop RGEs and the quasi fixed point from two-loop RGEs appear at about 2~3 TeV, while, for a light fourth generation (right side), their locations at the energy scale differ by two orders of magnitude.