One-loop Higgs boson production at the Linear Collider within the general two-Higgs-doublet model: e+e- versus gamma-gamma

TL;DR

This paper analyzes one-loop Higgs production at Linear Colliders within the general 2HDM, highlighting large radiative corrections and distinctive interference effects that differentiate it from the Standard Model and MSSM.

Contribution

It provides updated calculations of Higgs pair and single production rates in the 2HDM, emphasizing the role of triple Higgs self-interactions and interference effects in collider phenomenology.

Findings

Higgs pair production cross-sections range from 10-100 fb at 0.5 TeV.

Radiative corrections can reach about 50%.

Distinctive interference effects in gamma-gamma to Higgs processes.

Abstract

We present an updated overview on the phenomenology of one-loop Higgs boson production at Linear Colliders within the general Two-Higgs-Doublet Model (2HDM). First we report on the Higgs boson pair production, and associated Higgs-Z boson production, at O(alpha^3_{ew}) from e+e- collisions. These channels furnish cross-sections in the range of 10-100 fb for Ecm=0.5 TeV and exhibit potentially large radiative corrections (of order 50%), whose origin can be traced back to the genuine enhancement capabilities of the triple Higgs boson self-interactions. Next we consider the loop-induced production of a single Higgs boson from direct gamma-gamma scattering. We single out sizable departures from the corresponding rates in the Standard Model, which are again correlated to trademark dynamical features of the 2HDM -- namely the balance of the non-standard Higgs/gauge, Higgs/fermion and Higgs self-interactions leading to sizable (destructive) interference effects. This pattern of quantum effects is unmatched in the MSSM, and could hence provide distinctive footprints of non-supersymmetric Higgs boson physics. Both calculations are revisited within a common, brought-to-date framework and include, in particular, the most stringent bounds from unitarity and flavor physics.