Higgs interference effects in top-quark pair production in the 1HSM

Abstract

We present a next-to-leading-order (NLO) study of the process $pp(\to \{h_1,h_2\})\to t\bar{t}+X$ in the 1-Higgs-singlet extension of the Standard Model with an additional heavy Higgs boson $h_2$ that mixes with the light Higgs boson $h_1$. This process is subject to large interference effects between loop-induced Higgs-mediated amplitudes and the QCD continuum background which tend to overcompensate any resonance contributions. A reliable modelling of the resulting top-pair invariant mass shapes requires the inclusion of higher-order QCD corrections, which are presented here. The computation of these NLO corrections is exact in all contributions but in the class of non-factorisable two-loop diagrams which are included in an approximate way such that all infrared singular limits are preserved. We present numerical results for several benchmark points with heavy Higgs masses in the range $700$--$3000$ GeV considering the production of stable top quarks. We find that the interference effects dominate the BSM signal yielding sharp dip structures instead of resonance peaks. The significance and excludability of the BSM effect is explored for the LHC Run 2, Run 3 and HL-LHC.

32 pages, 11 figures, 5 tables, version to appear in JHEP

References in corpus (31)

• The automated computation of tree-level and next-to-leading order differential cross sections, and their matching to parton shower simulations
• Matching NLO QCD computations with Parton Shower simulations: the POWHEG method
• FeynRules - Feynman rules made easy
• Vector boson pair production at the LHC
• LHC Phenomenology of an Extended Standard Model with a Real Scalar Singlet
• SusHi: A program for the calculation of Higgs production in gluon fusion and bottom-quark annihilation in the Standard Model and the MSSM
• Complex Singlet Extension of the Standard Model
• Status of the Higgs Singlet Extension of the Standard Model after LHC Run 1
• Precise predictions for the Higgs-boson decay H -> W W/Z Z -> 4 leptons
• Singlet-Catalyzed Electroweak Phase Transitions and Precision Higgs Studies
• A second Higgs from the Higgs portal
• Polarizing the Dipoles
• Top pair invariant mass distribution: a window on new physics
• Exploring Resonant di-Higgs production in the Higgs Singlet Model
• New Physics in LHC Higgs boson pair production
• Top-quark pair hadroproduction at next-to-next-to-leading order in QCD
• Precision calculations for the Higgs decays H-->ZZ/WW-->4leptons
• Measuring Hidden Higgs and Strongly-Interacting Higgs Scenarios
• Challenges and opportunities for heavy scalar searches in the $t\bar{t}$ channel at the LHC
• Benchmarking Di-Higgs Production in Various Extended Higgs Sector Models
• Hiding the Higgs Boson with Multiple Scalars
• The Electro-Weak Phase Transition at Colliders: Confronting Theoretical Uncertainties and Complementary Channels
• Interference Effects in $t\bar{t}$ Production at the LHC as a Window on New Physics
• Universal Doublet-Singlet Higgs Couplings and phenomenology at the CERN Large Hadron Collider
• Resonant top pair searches at the LHC: a window to electroweak phase transition
• Bump-hunting in LHC ttbar events
• The Electro-Weak Phase Transition at Colliders: Discovery Post-Mortem
• Higgs interference effects at the one-loop level in the 1-Higgs-Singlet extension of the Standard Model
• On interference effects in top-philic decay chains
• H1jet, a fast program to compute transverse momentum distributions
• Model-independent approach for incorporating interference effects in collider searches for new resonances

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• Top-quark pair production as a probe of light top-philic scalars and anomalous Higgs interactions
• Search for heavy pseudoscalar and scalar bosons decaying to a top quark pair in proton-proton collisions at $\sqrt{s}$ = 13 TeV
• ALP-ine quests at the LHC: hunting axion-like particles via peaks and dips in $t\bar{t}$ production