Search for heavy neutral CP-even Higgs within Type-IV 2HDM at a future linear collider

In this paper, the production process $e^- e^+ \rightarrow A H$ is analyzed in the context of the type IV 2HDM and the question of observability of a neutral CP-even Higgs boson $H$ at a linear collider operating at $\sqrt{s}=1$ TeV is addressed. The CP-odd Higgs is assumed to experience a gauge-Higgs decay as $A\rightarrow ZH$ with hadronic decay of $Z$ boson as the signature of signal events. The production chain is thus $e^+e^- \rightarrow AH \rightarrow ZHH \rightarrow jj\ell\ell\ell\ell$ where $\ell$ is a $\tau$ or $\mu$. Four benchmark points with different mass hypotheses are assumed for the analysis. The Higgs mass $m_H$ is assumed to vary within the range 150-300 GeV in increments of 50 GeV. The anti-$k_t$ algorithm is used to perform the jet reconstruction. Results indicate that the neutral CP-even Higgs $H$ is observable through this production mechanism using the di-muon invariant mass distribution with possibility of mass measurement. The corresponding signal significances exceed $5\sigma$ at integrated luminosity of 3000 $fb^{-1}$.