# Two-Higgs-doublet type-II and -III models and $$t\rightarrow c h$$ at the LHC

The European Physical Journal C, Jun 2016

We study the constraints of the generic two-Higgs-doublet model (2HDM) type-III and the impacts of the new Yukawa couplings. For comparisons, we revisit the analysis in the 2HDM type-II. To understand the influence of all involving free parameters and to realize their correlations, we employ a $$\chi$$-square fitting approach by including theoretical and experimental constraints, such as the S, T, and U oblique parameters, the production of standard model Higgs and its decay to $$\gamma \gamma$$, $$WW^*/ZZ^*$$, $$\tau ^+\tau ^-$$, etc. The errors of the analysis are taken at 68, 95.5, and $$99.7~\%$$ confidence levels. Due to the new Yukawa couplings being associated with $$\cos (\beta -\alpha )$$ and $$\sin (\beta -\alpha )$$, we find that the allowed regions for $$\sin \alpha$$ and $$\tan \beta$$ in the type-III model can be broader when the dictated parameter $$\chi _F$$ is positive; however, for negative $$\chi _F$$, the limits are stricter than those in the type-II model. By using the constrained parameters, we find that the deviation from the SM in $$h\rightarrow Z\gamma$$ can be of $$\mathcal{O}(10~\%)$$. Additionally, we also study the top-quark flavor-changing processes induced at the tree level in the type-III model and find that when all current experimental data are considered, we get $$Br(t\rightarrow c(h, H) )< 10^{-3}$$ for $$m_h=125.36$$ and $$m_H=150$$ GeV, and $$Br(t\rightarrow cA)$$ slightly exceeds $$10^{-3}$$ for $$m_A =130$$ GeV.

This is a preview of a remote PDF: https://link.springer.com/content/pdf/10.1140%2Fepjc%2Fs10052-016-4167-9.pdf

A. Arhrib, R. Benbrik, Chuan-Hung Chen. Two-Higgs-doublet type-II and -III models and $$t\rightarrow c h$$ at the LHC, The European Physical Journal C, 2016, 328, DOI: 10.1140/epjc/s10052-016-4167-9