One-Loop Corrections to the Perturbative Unitarity Bounds in the $CP$-Conserving Two-Higgs Doublet Model with a Softly Broken ${\mathbb{Z}}_2$ Symmetry

Abstract

We compute all of the one-loop corrections that are enhanced, $O({\lambda }_i{\lambda }_j/16{\pi }^2)$, in the limit $s\gg |{\lambda }_i|v^2\gg M_W^2$, $s\gg m_{12}^2$ to all the $2\to 2$ longitudinal vector boson and Higgs boson scattering amplitudes in the $CP$-conserving two-Higgs doublet model with a softly broken ${\mathbb{Z}}_2$ symmetry. In the two simplified scenarios we study, the typical bound we find is $|{\lambda }_i(s)|⪅4$.

Comments: v2: 1 plot corrected, other minor changes, version to appear in JHEP