The LHC di-photon Higgs signal predicted by little Higgs models

TL;DR

This paper compares the di-photon Higgs signal predictions of various little Higgs models at the LHC, finding significant suppression compared to the Standard Model, which impacts the detectability of the Higgs boson.

Contribution

It provides a comparative analysis of di-photon Higgs signals in different little Higgs models, highlighting the extent of signal suppression relative to the Standard Model.

Findings

Di-photon signal is always suppressed in little Higgs models.

Suppression ranges from mild (~10%) to severe (~90%) depending on the model.

Detection of the Higgs via di-photon channel is more challenging in these models.

Abstract

Little Higgs theory naturally predicts a light Higgs boson whose most important discovery channel at the LHC is the di-photon signal $pp\to h\to \gamma\gamma$. In this work we perform a comparative study for this signal in some typical little Higgs models, namely the littlest Higgs model (LH), two littlest Higgs models with T-parity (named LHT-I and LHT-II) and the simplest little Higgs modes (SLH). We find that compared with the Standard Model prediction, the di-photon signal rate is always suppressed and the suppression extent can be quite different for different models. The suppression is mild ($\lsim 10%$) in the LH model but can be quite severe ($\simeq 90%$) in other three models. This means that discovering the light Higgs boson predicted by the little Higgs theory through the di-photon channel at the LHC will be more difficult than discovering the SM Higgs boson.