Modified top quark condensation model with the extra heavy fermion, the $125$ GeV Pseudo - Goldstone boson, and the additional heavy scalar bosons

Abstract

We discuss the modified top quark condensation model proposed in \cite{VZ2015}. This construction was inspired by the top - seesaw scenario, in which the extra heavy fermion $\chi$ is added that may be paired with the top quark. Besides, this model incorporates the ideas of the Little Higgs scenario, in which the $125$ GeV scalar particle appears as a Pseudo - Goldstone boson. This model admits (in addition to the $125$ GeV scalar boson $H$) the heavier scalar excitation $H^\prime$. We consider the region of parameters, where its mass is $M_{H^\prime} \sim 1$ TeV, the width of $H^\prime$ is $\Gamma_{H^\prime} \sim 0.3 M_{H^\prime}$, while the mass of the heavy fermion is $m_\chi \sim 1$ TeV. We find that in this model the value of the cross - section $\sigma_{pp \to H^\prime + X \to \gamma+\gamma + X}$ for $\sqrt{s}=13$ TeV is essentially smaller than the present experimental upper bound. Besides, we find, that for the chosen values of parameters there should exist the CP - even scalar boson with mass $\approx 2 m_\chi$ and very small width. In addition, the model predicts the existence of the extra neutral CP even scalar boson and the charged scalar boson with masses of the order of $1$ TeV.