Flavon Signatures at the HL-LHC

TL;DR

This paper explores the potential to detect a new scalar 'Flavon' particle at the HL-LHC through its decay channels, providing a novel way to probe the Higgs potential and fermion mass hierarchy.

Contribution

It demonstrates that Flavon production and decay channels can be used to explore new physics at the HL-LHC, especially for a Flavon with mass around twice the top quark mass.

Findings

Heavy Flavon with mass ~2m_t can be detected with 3-5 sigma significance.

Decay channels to ZZ and tc are promising for Flavon detection.

Analysis is based on 3000 fb$^{-1}$ of data at 14 TeV.

Abstract

The detection of a single Higgs boson at the Large Hadron Collider (LHC) has allowed one to probe some properties of it, including the Yukawa and gauge couplings. However, in order to probe the Higgs potential, one has to rely on new production mechanisms, such as Higgs pair production. In this paper, we show that such a channel is also sensitive to the production and decay of a so-called `Flavon' field ($H_F$), a new scalar state that arises in models that attempt to explain the hierarchy of the Standard Model (SM) fermion masses. Our analysis also focuses on the other decay channels involving the Flavon particle, specifically the decay of the Flavon to a pair of $Z$ bosons ($H_F \to Z Z$) and the concurrent production of a top quark and charm quark ($H_F\to tc$), having one or more leptons in the final states. In particular, we show that, with 3000 fb$^{-1}$ of accumulated data at 14 TeV (the Run 3 stage) of the LHC an heavy Flavon $H_F$ with mass $M_{H_F} \simeq 2m_t $ can be explored with $3\sigma -5\sigma $ significance through these channels.