The 2023 International Workshop on the High Energy Circular Electron Positron Collider

Probing dark QCD sector through the Higgs portal with machine learning at the LHC

Not scheduled

20m

CEPC Room 1 (GrandHotelNanjing)

Talk 10: Physics beyond the SM BSM

Speaker

jia zhang

Description

Abstract: The QCD-like dark sector with GeV-scale dark hadrons has the potential to
generate new signatures at the Large Hadron Collider (LHC). In this paper, we consider
a singlet scalar mediator in the tens of GeV-scale that connects the dark sector and the
Standard Model (SM) sector via the Higgs portal. We focus on the Higgs-strahlung process,
qq
0 → W∗ → W H, to produce a highly boosted Higgs boson. Our scenario predicts two
different processes that can generate dark mesons: (1) the cascade decay from the Higgs
boson to two light scalar mediators and then to four dark mesons; (2) the Higgs boson
decaying to two dark quarks, which then undergo a QCD-like shower and hadronization to
produce dark mesons. We apply machine learning techniques, such as Convolutional Neural
Network (CNN) and Energy Flow Network (EFN), to the fat-jet structure to distinguish
these signal processes from large SM backgrounds. We find that the branching ratio of the
Higgs boson to two light scalar mediators can be constrained to be less than about 10% at
14 TeV LHC with L = 3000 fb−1
.