Unitarity constraints for Yukawa couplings in the two Higgs doublet model type III

TL;DR

This paper derives unitarity constraints on Yukawa couplings in the Two Higgs Doublet Model type III, providing bounds that are less model-dependent and independent of scalar masses or mixing angles.

Contribution

It introduces a systematic method using partial wave expansion to establish unitarity bounds on Yukawa couplings in the 2HDM type III, independent of scalar sector parameters.

Findings

Constraints are weaker than phenomenological bounds but more general.

Unitarity bounds are independent of scalar masses and mixing angles.

The method provides the lowest assumptions among theoretical limits.

Abstract

Unitarity constraints for Yukawa couplings are considered in the Two Higgs Doublet Model type III, by using a general expansion in partial waves for fermionic scattering processes. Constraints over general Flavor Changing Neutral Currents are found from that systematic, such bounds compete with those coming from Lagrangian perturbativity requirement but are weaker than those imposed from phenomenological processes and precision tests. Nevertheless, for bounds based on unitarity the number of assumptions is the lowest among phenomenological and theoretical limits. Indeed, these new theoretical constraints are independent of scalar masses or mixing angles for this extended Higgs sector, making them less model dependent.