Radiative corrections to the Yukawa couplings in two Higgs doublet models

TL;DR

This paper calculates one-loop radiative corrections to Yukawa couplings in various Two Higgs Doublet Models (THDMs) to help distinguish their types through precise measurements at the ILC, potentially identifying the Higgs sector structure indirectly.

Contribution

It provides detailed one-loop calculations of Yukawa coupling deviations in all THDM types, enabling model discrimination via future collider data.

Findings

Yukawa coupling scale factors differ significantly among THDM types.

Radiative corrections enhance the distinguishability of THDM types.

Differences are measurable at the ILC even without direct Higgs detection.

Abstract

A pattern of deviations in coupling constants of Standard Model (SM)-like Higgs boson from their SM predictions indicates characteristics of an extended Higgs sector. In particular, Yukawa coupling constants can deviate in different patterns in four types of Two Higgs Doublet Models (THDMs) with a softly-broken Z_2 symmetry. We can discriminate types of THDMs by measuring the pattern of these deviations. We calculate Yukawa coupling constants of the SM-like Higgs boson with radiative corrections in all types of Yukawa interactions in order to compare to future precision data at the International Linear Collider (ILC). We perform numerical computations of scale factors, and evaluate differences between the Yukawa couplings in THDMs and those of the SM at the one-loop level. We find that scale factors in different types of THDMs do not overlap each other even in the case with maximum radiative corrections if gauge couplings are different from the SM predictions large enough to be measured at the ILC. Therefore, in such a case, we can indirectly determine the type of the THDM at the ILC even without finding additional Higgs bosons directly.