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.