Search for the Elusive Higgs Boson Using Jet Structure at LHC

TL;DR

The paper addresses the challenge of discovering a light non-SM Higgs that decays through $h\to2\chi\to4g$ by studying associated $Wh$ production at the LHC. It develops two complementary strategies depending on $m_\chi$: an electromagnetic-calorimeter–based method for $m_\chi=4$ GeV and a jet-substructure method for $m_\chi=8$ GeV, demonstrating feasibility with about 7σ significance in the former and up to ~3.8σ in the latter for 30 fb$^{-1}$. The results illustrate a viable path to observe such elusive Higgs decays, with cross sections normalized to the SM in the study but readily rescalable to other models and BRs. The work highlights the importance of jet substructure and highly granular calorimetry in disentangling boosted cascade decays from QCD backgrounds, while noting limitations like underlying-event modeling and the need for more realistic simulations.

Abstract

We consider the production of a light non-standard model Higgs boson of order $100~\GEV$ with an associated $W$ boson at CERN Large Hadron Collider. We focus on an interesting scenario that, the Higgs boson decays predominately into two light scalars $χ$ with mass of few GeV which sequently decay into four gluons, i.e. $h\to 2χ\to 4g$. Since $χ$ is much lighter than the Higgs boson, it will be highly boosted and its decay products, the two gluons, will move close to each other, resulting in a single jet for $χ$ decay in the detector. By using electromagnetic calorimeter-based and jet substructure analyses, we show in two cases of different $χ$ masses that it is quite promising to extract the signal of Higgs boson out of large QCD background.