Signatures of vector-like top partners decaying into new neutral scalar or pseudoscalar bosons

Abstract

We explore the phenomenology of models containing one Vector-Like Quark (VLQ), $t^{\prime }$, which can decay into the Standard Model (SM) top quark, $t$, and a new spin-0 neutral boson, $S$, the latter being either a scalar or pseudoscalar state. We parametrise the underlying interactions in terms of a simplified model which enables us to capture possible Beyond the SM (BSM) scenarios. We discuss in particular three such scenarios: one where the SM state is supplemented by an additional scalar, one which builds upon a 2-Higgs Doublet Model (2HDM) framework and another which realises a Composite Higgs Model (CHM) through partial compositeness. Such exotic decays of the $t^{\prime }$ can be competitive with decays into SM particles, leading to new possible discovery channels at the Large Hadron Collider (LHC). Assuming $t^{\prime }$ pair production via strong interactions, we design signal regions optimised for one $t^{\prime }\to St$ transition (while being inclusive on the other \bar{t'} decay, and vice versa), followed by the decay of $S$ into the two very clean experimental signatures $S\to \gamma \gamma$ and $S\to Z(\to {\ell }^{+}{\ell }^{-})\gamma$. We perform a dedicated signal-to-background analysis in both channels, by using Monte Carlo (MC) event simulations modelling the dynamics from the proton-proton to the detector level. Under the assumption of BR$(t^{\prime }\to St)=100\%$, we are therefore able to realistically quantify the sensitivity of the LHC to both the $t^{\prime }$ and $S$ masses, assuming both current and foreseen luminosities. This approach paves the way for the LHC experiments to surpass current VLQ search strategies based solely on $t^{\prime }$ decays into SM bosons ($W^{\pm },Z$, $h$).

50 pages, 21 figures, published in JHEP. v4 with an update of figure 14

References in corpus (40)

• The automated computation of tree-level and next-to-leading order differential cross sections, and their matching to parton shower simulations
• The anti-k_t jet clustering algorithm
• An Introduction to PYTHIA 8.2
• FastJet user manual
• Parton distributions for the LHC
• Asymptotic formulae for likelihood-based tests of new physics
• DELPHES 3, A modular framework for fast simulation of a generic collider experiment
• Theory and phenomenology of two-Higgs-doublet models
• LHAPDF6: parton density access in the LHC precision era
• Parton distributions from high-precision collider data
• UFO - The Universal FeynRules Output
• -- HATHOR -- HAdronic Top and Heavy quarks crOss section calculatoR
• MadAnalysis 5, a user-friendly framework for collider phenomenology
• Matching matrix elements and shower evolution for top-quark production in hadronic collisions
• HiggsBounds-4: Improved Tests of Extended Higgs Sectors against Exclusion Bounds from LEP, the Tevatron and the LHC
• A custodial symmetry for Zbb
• Collider Probes of Axion-Like Particles
• Lee-Quigg-Thacker Bounds for Higgs Boson Masses in a Two-Doublet Model
• Beyond the Minimal Composite Higgs Model
• Fermionic UV completions of Composite Higgs models
• A First Top Partner Hunter's Guide
• Model Independent Framework for Searches of Top Partners
• Scenarii for interpretations of the LHC diphoton excess: two Higgs doublets and vector-like quarks and leptons
• UV descriptions of composite Higgs models without elementary scalars
• Evaluation of three methods for calculating statistical significance when incorporating a systematic uncertainty into a test of the background-only hypothesis for a Poisson process
• Impact of a Higgs boson at a mass of 126 GeV on the standard model with three and four fermion generations
• Confronting new physics theories to LHC data with MadAnalysis 5
• The Photophobic ALP
• Beyond the Minimal Top Partner Decay
• Novel signatures for vector-like quarks
• Common exotic decays of top partners
• Interpreting the 750 GeV diphoton excess in minimal extensions of Two-Higgs-Doublet models
• Exotic decays of top partners: mind the search gap
• Top Polarization in Stop Production at the LHC
• Top quark FCNCs in extended Higgs sectors
• Implications of a High-Mass Diphoton Resonance for Heavy Quark Searches
• Exotic Signals of Vectorlike Quarks
• Vector-like quarks coupling discrimination at the LHC and future hadron colliders
• Six Top Messages of New Physics at the LHC
• A Concrete Composite 2-Higgs Doublet Model

Cited by in corpus (36)

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• Hunting for top partner with a new signature at the LHC
• Signals with six bottom quarks for charged and neutral Higgs bosons
• Discovery prospects of a vectorlike top partner decaying to a singlet boson
• Vector-like quarks: status and new directions at the LHC
• Probing Charged Higgs Bosons in the 2-Higgs Doublet Model Type-II with Vector-Like Quarks
• Machine learning-enhanced search for a vectorlike singlet $B$ quark decaying to a singlet scalar or pseudoscalar
• Exploring maverick top partner decays at the LHC
• Composite dark matter phenomenology in the presence of lighter degrees of freedom
• Heavy vector-like quarks decaying to exotic scalars: a case study with triplets
• Anatomy of Vector-Like Top-Quark Models in the Alignment Limit of the 2-Higgs Doublet Model Type-II
• Search for pair production of the heavy vectorlike top partner in same-sign dilepton signature at the HL-LHC
• Exploring extended Higgs sectors via pair production at the LHC
• Single production of vector-like $T$ quark at future high-energy linear $e^{+}{e}^{-}$ collider
• New Limits on Coloured Three Jet Resonances
• Pair production of the singlet vector-like B quark at the CLIC
• Probing an MeV-Scale Scalar Boson in Association with a TeV-Scale Top-Quark Partner at the LHC
• Pseudoscalar pair production via off-shell Higgs in composite Higgs models
• Composite Higgs revealed in Higgs pair photo-production at future colliders
• Composite 2-Higgs Doublet Model: Strong Effects on Higgs Pair Production
• Phase transition and gravitational waves in maximally symmetric composite Higgs model
• Exploring vector-like $B$-quark pair production at CLIC in fully hadronic final states
• Tagging fully hadronic exotic decays of the vectorlike $\mathbf{B}$ quark using a graph neural network
• Searching for single production of vectorlike quarks decaying into Wb at a future muon-proton collider
• Vector-like quarks decaying into singly and doubly charged bosons at LHC
• Impact of hidden heavy Higgs channels of VLB-Quarks below 1 TeV in 2HDM
• Real and Complex Singlet-Scalar Benchmarks with a Vector-Like Down Quark for $B\to X_s\gamma$ and $B_s-{\bar{B}}_s$ Mixing
• Machine learning tagged boosted dark photon: A signature of fermionic portal matter at the LHC
• Search for pair production of heavy resonances in final states with a photon and large-radius jets in proton-proton collisions at $\sqrt{s}$ = 13 TeV
• Testing charge-radius coupling of the composite Higgs boson at hadron colliders
• Tagging ultra-boosted jets at FCC-hh using machine learning techniques