Diphoton signals for the Georgi-Machacek scenario at the Large Hadron Collider

Abstract

The diphoton channel for exploring the Georgi-Machacek (GM) scenario containing scalar triplets at the Large Hadron Collider (LHC) has been identified as germane, and subjected to a detailed study. The scalar spectrum of the model, which imposes a custodial SU(2) on the potential, gets classified into a 5-plet, a 3-plet and two singlets under the custodial symmetry. While most attempts to probe or constrain the scenario at the LHC depend largely on signals of charged scalars, we point out that the custodial SU(2) singlet state H can have a substantial branching ratio (amounting to a few percent) into two photons. We carry out a detailed simulation of the resulting signal and the standard model backgrounds, obtaining the signal significance in different regions of the parameter space using the profile likelihood ratio method. Substantial regions of the GM parameter space is thus shown to be accessible to LHC studies, both at the high-luminosity run with $\int \mathcal{L}dt=3000f{b}^{-1}$, and also in Run-3 with $\int \mathcal{L}dt=300f{b}^{-1}$, even after folding in systematic errors. We have also demonstrated that a rather subtantial improvement in the signal significance is achieved by switching over from a cut-based analysis to one based on neural network.

35 pages, 7 figures, 4 tables

References in corpus (23)

• The automated computation of tree-level and next-to-leading order differential cross sections, and their matching to parton shower simulations
• Combined Measurement of the Higgs Boson Mass in $pp$ Collisions at $\sqrt{s}=7$ and 8 TeV with the ATLAS and CMS Experiments
• Search for Scalar Diphoton Resonances in the Mass Range $65-600$ GeV with the ATLAS Detector in $pp$ Collision Data at $\sqrt{s}$ = 8 $TeV$
• A search for a doubly-charged Higgs boson in pp collisions at sqrt(s) = 7 TeV
• A measurement of the Higgs boson mass in the diphoton decay channel
• HiggsTools: BSM scalar phenomenology with new versions of HiggsBounds and HiggsSignals
• The decoupling limit in the Georgi-Machacek model
• Search for high-mass diphoton resonances in proton-proton collisions at 13 TeV and combination with 8 TeV search
• Measurements of Higgs boson production cross sections and couplings in the diphoton decay channel at $\sqrt{s}=$ 13 TeV
• Searches for additional Higgs bosons and for vector leptoquarks in $\tau \tau$ final states in proton-proton collisions at $\sqrt{s}$ = 13 TeV
• Indirect constraints on the Georgi-Machacek model and implications for Higgs couplings
• A Minimal Type II Seesaw Model
• Search for doubly and singly charged Higgs bosons decaying into vector bosons in multi-lepton final states with the ATLAS detector using proton-proton collisions at $\sqrt{s}$ = 13 TeV
• Search for resonances decaying into photon pairs in 139 fb${}^{-1}$ of $pp$ collisions at $\sqrt{s}=$ 13 TeV with the ATLAS detector
• A 95 GeV Higgs Boson in the Georgi-Machacek Model
• The 95 GeV Excess in the Georgi-Machacek Model: Single or Twin Peak Resonance
• Updated constraints on Georgi-Machacek model, and its electroweak phase transition and associated gravitational waves
• Unavoidable Higgs coupling deviations in the $Z_2$-symmetric Georgi-Machacek model
• More Constraints on the Georgi-Machacek Model
• New physics implications of VBF searches exemplified through the Georgi-Machacek model
• Some new observations for the Georgi-Machacek scenario with triplet Higgs
• The $\rho$ parameter and the CDF W-mass anomaly: observations on the role of scalar triplets
• Revisiting the decoupling limit of the Georgi-Machacek model with a scalar singlet

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• Interpretation of 95 GeV Excess within the Georgi-Machacek Model in Light of Positive Definiteness Constraints
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