Diphoton decay of the Higgs boson and new bound states of top and anti-top quarks

TL;DR

This paper investigates how a hypothesized bound state of 6 top and 6 anti-top quarks affects Higgs boson decay and production, using LHC data to constrain its properties and potential existence.

Contribution

It introduces a model estimating the impact of a 12-quark bound state on Higgs processes and identifies parameter regions consistent with experimental data.

Findings

Two parameter regions fit LHC data at 3 sigma: near SM values with $m_S > 400$ GeV and a lower mass region with $m_S \,\sim 220$ GeV.

The model predicts a correlation between Higgs diphoton decay and gluon fusion amplitudes.

The bound state could significantly alter Higgs decay and production if within certain mass ranges.

Abstract

We consider the constraints, provided by the LHC results on Higgs boson decay into 2 photons and its production via gluon fusion, on the previously proposed Standard Model (SM) strongly bound state $S$ of 6 top quarks and 6 anti-top quarks. A correlation is predicted between the ratios $\kappa_{\gamma}$ and $\kappa_g$ of the Higgs diphoton decay and gluon production amplitudes respectively to their SM values. We estimate the contribution to these amplitudes from one loop diagrams involving the 12 quark bound state $S$ and related excited states using an atomic physics based model. We find two regions of parameter space consistent with the ATLAS and CMS data on ($\kappa_{\gamma}$, $\kappa_g$) at the 3 sigma level: a region close to the SM values ($\kappa_{\gamma}=1$, $\kappa_g =1$) with the mass of the bound state $m_S > 400$ GeV and a region with ($\kappa_{\gamma} \sim 3/2$, $\kappa_g \sim -3/4$) corresponding to a bound state mass of $m_S \sim 220$ GeV.