Search for Light Scalars Produced in Association with Muon Pairs for $\sqrt{s}$ = 250 GeV at the ILC

TL;DR

This study explores the potential of the ILC to detect light scalar particles associated with muon pairs in a model-independent way, using the recoil technique at 250 GeV, and provides preliminary exclusion limits for various Higgs masses.

Contribution

It presents a novel, model-independent analysis method for searching light scalars at the ILC using the recoil technique with muon pairs, supported by full detector simulation.

Findings

Preliminary exclusion limits for Higgs masses between 30 and 115 GeV.

Demonstrates the effectiveness of the recoil technique with muon pairs at 250 GeV.

Shows the ILC's potential to discover or exclude light scalars with suppressed couplings.

Abstract

In many models with extended Higgs sectors, $e.g.$ 2HDM, NMSSM, there exists a light scalar $h$, lighter than the Standard Model (SM) like Higgs, and the coupling of $hZZ$ can be very small, as expected from the likeness of the 125 GeV Higgs boson measured at the LHC to the SM Higgs boson. Such a light scalar with suppressed couplings to the $Z$ boson would have escaped detection at LEP due to its limited luminosity. With a factor of 1000 higher luminosity and polarized beams, the International Linear Collider (ILC) is expected to have substantial discovery potential for such states. Furthermore, searches for additional scalars at LEP and LHC are usually dependent on the model details, such as decay channels. Thus, it is necessary to have a more general analysis with model-independent assumptions. In this work, we perform a search for a light higgs boson produced in association with $Z$ boson at the ILC with a center-of-mass energy of 250 GeV, using the full Geant4-based simulation of the ILD detector concept. In order to be as model-independent as possible, the analysis is performed using the recoil technique, in particular with the $Z$ boson decaying into a pair of muons. As a preliminary result, the ILC's exclusion limits will be shown for different higgs masses between 30 and 115 GeV.