Searching for a Light Higgs Boson via the Yukawa Process at Lepton Colliders

TL;DR

This paper investigates the potential to detect a light pseudoscalar Higgs boson in an extended Higgs sector at the ILC, focusing on the Yukawa production process to fully explore the parameter space and reconstruct the particle mass.

Contribution

It demonstrates that the Yukawa process at the ILC can comprehensively probe the parameter space of a light pseudoscalar Higgs in the Type-X two Higgs doublet model and effectively reconstruct its mass.

Findings

Parameter space fully examined at 5σ significance

Mass reconstruction of the light pseudoscalar achieved

Yukawa process effectively minimizes background events

Abstract

We explore the prospect of Yukawa production of a light boson which can exist in an extended Higgs sector. A particularly interesting case is the light pseudoscalar in Type-X two Higgs doublet model which can explain the anomalous magnetic moment of muon at large $\tan\beta$. Considering ILC $Higgs$ $factory$ with $\sqrt{s}=250$ GeV, we show that the available parameter space can be fully examined by the (tau) Yukawa process at $5\sigma$. We also demonstrate the mass reconstruction of such a light particle which helps to sizably minimize the background events.