Probing loop effects in wrong-sign Yukawa coupling region of Type-II 2HDM

Abstract

AbstractIn the framework of 2HDM, we explore the wrong-sign Yukawa region with direct and indirect searches up to one-loop level. The direct searches include the latest $$H/A \rightarrow f{\bar{f}}, VV, Vh, hh$$ H / A → f f ¯ , V V , V h , h h reports at current LHC, and the study of indirect Higgs precision measurements works with current LHC, future HL-LHC and CEPC. At tree level of Type-II 2HDM, for degenerate heavy Higgs mass $$m_A=m_H=m_{H^\pm }<800$$ m A = m H = m H ± < 800 GeV, the wrong-sign Yukawa regions are excluded largely except for the tiny allowed region around $$\cos (\beta -\alpha )\in (0.2,0.3)$$ cos ( β - α ) ∈ ( 0.2 , 0.3 ) under the combined Higgs constraints. The excluded region is also nearly independent of parameter $$m_{12}$$ m 12 or $$\lambda v^2=m_A^2-m_{12}^2/(\sin \beta \cos \beta )$$ λ v 2 = m A 2 - m 12 2 / ( sin β cos β ) . The situation changes a lot after including loop corrections to the indirect searches, for example $$m_A=1500 \text {~GeV}$$ m A = 1500 GeV , the region with $$\lambda v^2<0$$ λ v 2 < 0 will be stronger constrained to be totally excluded. Whilst parameter space with $$\lambda v^2>0$$ λ v 2 > 0 would get larger survived wrong-sign region for $$m_A=800 ~\text {~GeV}$$ m A = 800 GeV compared to it at tree level. We also conclude Higgs direct searches works better on constraining $$\lambda v^2 \approx 0$$ λ v 2 ≈ 0 GeV range than theoretical constraints. We also find that the loop-level wrong-sign Yukawa limit only occurs at mass decoupling scale.