Single Higgs-boson production through gamma-gamma scattering within the general 2HDM

TL;DR

This paper investigates single Higgs boson production via gamma-gamma scattering in the general 2HDM at linear colliders, showing potential for significantly enhanced production rates compared to the Standard Model, especially with lighter charged Higgs.

Contribution

It analyzes Higgs production mechanisms in the general 2HDM, highlighting how Higgs self-interactions and charged Higgs mass influence production rates, which can surpass SM expectations.

Findings

Production cross-section for gamma gamma-> h can reach 0.1-1 pb.

e+e- --> e+e- + h cross-section can reach ~0.01 pb.

Rates are sensitive to charged Higgs mass and Higgs self-couplings.

Abstract

The production of a single neutral Higgs boson h through (loop-induced) gamma-gamma collisions is explored in the context of the linear colliders within the general Two-Higgs-Doublet Model (2HDM). Two different mechanisms are analyzed: on the one hand, the scattering gamma gamma-> h of two real photons in a gamma-gamma collider; on the other, the more traditional mechanism of virtual photon fusion, e+e- -->e+e- + h. Owing to the peculiar properties of the Higgs boson self-interactions within the general 2HDM, we find that the overall production rates can be boosted up significantly, provided the charged Higgs mass is not too heavy. For example, if the latter is slightly above 100 GeV and, in addition, the lightest CP-even Higgs boson falls in the ballpark of the LEP bound on the SM Higgs mass up to a few hundred GeV, the cross-sections may typically render \sigma(gamma gamma-> h)= 0.1-1 pb and \sigma(e+e- --> e+e- + h)\sim 0.01 pb -- in both cases well above the SM prediction. Although for charged Higgs masses above 300 GeV the rates become virtually insensitive to the Higgs boson self-couplings, a significant tail of non-SM effects produced by the combined contribution of the Yukawa couplings and gauge bosons could still reveal a smoking gun.