Abstract
We explore the phenomenology of models containing one Vector-Like Quark (VLQ), t′, 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′ can be competitive with decays into SM particles, leading to new possible discovery channels at the Large Hadron Collider (LHC). Assuming t′ pair production via strong interactions, we design signal regions optimised for one t′ → S t transition (while being inclusive on the other \( \overline{t} \)′ decay, and vice versa), followed by the decay of S into the two very clean experimental signatures S → γ γ and S → Z (→ ℓ +ℓ −)γ. 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′ → S t) = 100%, we are therefore able to realistically quantify the sensitivity of the LHC to both the t′ 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′ decays into SM bosons (W ±, Z , h).
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
References
O. Eberhardt et al., Impact of a Higgs boson at a mass of 126 GeV on the Standard Model with three and four fermion generations, Phys. Rev. Lett. 109 (2012) 241802 [arXiv:1209.1101] [INSPIRE].
M. Buchkremer, G. Cacciapaglia, A. Deandrea and L. Panizzi, Model independent framework for searches of top partners, Nucl. Phys. B 876 (2013) 376 [arXiv:1305.4172] [INSPIRE].
J.A. Aguilar-Saavedra, R. Benbrik, S. Heinemeyer and M. Pérez-Victoria, Handbook of vectorlike quarks: mixing and single production, Phys. Rev. D 88 (2013) 094010 [arXiv:1306.0572] [INSPIRE].
ATLAS collaboration, Combination of the searches for pair-produced vector-like partners of the third-generation quarks at \( \sqrt{s} \) = 13 TeV with the ATLAS detector, Phys. Rev. Lett. 121 (2018) 211801 [arXiv:1808.02343] [INSPIRE].
ATLAS collaboration, Search for pair production of heavy vector-like quarks decaying into hadronic final states in pp collisions at \( \sqrt{s} \) = 13 TeV with the ATLAS detector, Phys. Rev. D 98 (2018) 092005 [arXiv:1808.01771] [INSPIRE].
ATLAS collaboration, Search for new phenomena in events with same-charge leptons and b-jets in pp collisions at \( \sqrt{s} \) = 13 TeV with the ATLAS detector, JHEP 12 (2018) 039 [arXiv:1807.11883] [INSPIRE].
ATLAS collaboration, Search for pair production of heavy vector-like quarks decaying into high-pT W bosons and top quarks in the lepton-plus-jets final state in pp collisions at \( \sqrt{s} \) = 13 TeV with the ATLAS detector, JHEP 08 (2018) 048 [arXiv:1806.01762] [INSPIRE].
ATLAS collaboration, Search for pair- and single-production of vector-like quarks in final states with at least one Z boson decaying into a pair of electrons or muons in pp collision data collected with the ATLAS detector at \( \sqrt{s} \) = 13 TeV, Phys. Rev. D 98 (2018) 112010 [arXiv:1806.10555] [INSPIRE].
ATLAS collaboration, Search for pair production of up-type vector-like quarks and for four-top-quark events in final states with multiple b-jets with the ATLAS detector, JHEP 07 (2018) 089 [arXiv:1803.09678] [INSPIRE].
CMS collaboration, Search for vector-like quarks in events with two oppositely charged leptons and jets in proton-proton collisions at \( \sqrt{s} \) = 13 TeV, Eur. Phys. J. C 79 (2019) 364 [arXiv:1812.09768] [INSPIRE].
CMS collaboration, Search for top quark partners with charge 5/3 in the same-sign dilepton and single-lepton final states in proton-proton collisions at \( \sqrt{s} \) = 13 TeV, JHEP 03 (2019) 082 [arXiv:1810.03188] [INSPIRE].
CMS collaboration, Search for pair production of vector-like quarks in the bW \( \overline{b} \)W channel from proton-proton collisions at \( \sqrt{s} \) = 13 TeV, Phys. Lett. B 779 (2018) 82 [arXiv:1710.01539] [INSPIRE].
CMS collaboration, Search for pair production of vectorlike quarks in the fully hadronic final state, Phys. Rev. D 100 (2019) 072001 [arXiv:1906.11903] [INSPIRE].
J. Serra, Beyond the minimal top partner decay, JHEP 09 (2015) 176 [arXiv:1506.05110] [INSPIRE].
A. Anandakrishnan, J.H. Collins, M. Farina, E. Kuflik and M. Perelstein, Odd top partners at the LHC, Phys. Rev. D 93 (2016) 075009 [arXiv:1506.05130] [INSPIRE].
S. Banerjee, D. Barducci, G. Bélanger and C. Delaunay, Implications of a high-mass diphoton resonance for heavy quark searches, JHEP 11 (2016) 154 [arXiv:1606.09013] [INSPIRE].
B.A. Dobrescu and F. Yu, Exotic signals of vectorlike quarks, J. Phys. G 45 (2018) 08LT01 [arXiv:1612.01909] [INSPIRE].
J.A. Aguilar-Saavedra, D.E. López-Fogliani and C. Muñoz, Novel signatures for vector-like quarks, JHEP 06 (2017) 095 [arXiv:1705.02526] [INSPIRE].
M. Chala, Direct bounds on heavy toplike quarks with standard and exotic decays, Phys. Rev. D 96 (2017) 015028 [arXiv:1705.03013] [INSPIRE].
S. Colucci, B. Fuks, F. Giacchino, L. Lopez Honorez, M.H.G. Tytgat and J. Vandecasteele, Top-philic vector-like portal to scalar dark matter, Phys. Rev. D 98 (2018) 035002 [arXiv:1804.05068] [INSPIRE].
S. Banerjee, M. Chala and M. Spannowsky, Top quark FCNCs in extended Higgs sectors, Eur. Phys. J. C 78 (2018) 683 [arXiv:1806.02836] [INSPIRE].
H. Han, L. Huang, T. Ma, J. Shu, T.M.P. Tait and Y. Wu, Six top messages of new physics at the LHC, JHEP 10 (2019) 008 [arXiv:1812.11286] [INSPIRE].
J.H. Kim, S.D. Lane, H.-S. Lee, I.M. Lewis and M. Sullivan, Searching for dark photons with maverick top partners, Phys. Rev. D 101 (2020) 035041 [arXiv:1904.05893] [INSPIRE].
N. Bizot, G. Cacciapaglia and T. Flacke, Common exotic decays of top partners, JHEP 06 (2018) 065 [arXiv:1803.00021] [INSPIRE].
CMS collaboration, Search for vector-like charge 2/3T quarks in proton-proton collisions at \( \sqrt{s} \) = 8 TeV, Phys. Rev. D 93 (2016) 012003 [arXiv:1509.04177] [INSPIRE].
G. Cacciapaglia, T. Flacke, M. Park and M. Zhang, Exotic decays of top partners: mind the search gap, Phys. Lett. B 798 (2019) 135015 [arXiv:1908.07524] [INSPIRE].
ATLAS collaboration, Search for massive supersymmetric particles decaying to many jets using the ATLAS detector in pp collisions at \( \sqrt{s} \) = 8 TeV, Phys. Rev. D 91 (2015) 112016 [Erratum ibid. D 93 (2016) 039901] [arXiv:1502.05686] [INSPIRE].
G.C. Branco, P.M. Ferreira, L. Lavoura, M.N. Rebelo, M. Sher and J.P. Silva, Theory and phenomenology of two-Higgs-doublet models, Phys. Rept. 516 (2012) 1 [arXiv:1106.0034] [INSPIRE].
M. Badziak, Interpreting the 750 GeV diphoton excess in minimal extensions of two-Higgs-doublet models, Phys. Lett. B 759 (2016) 464 [arXiv:1512.07497] [INSPIRE].
A. Angelescu, A. Djouadi and G. Moreau, Scenarii for interpretations of the LHC diphoton excess: two Higgs doublets and vector-like quarks and leptons, Phys. Lett. B 756 (2016) 126 [arXiv:1512.04921] [INSPIRE].
A. Arhrib, R. Benbrik, S.J.D. King, B. Manaut, S. Moretti and C.S. Un, Phenomenology of 2HDM with vectorlike quarks, Phys. Rev. D 97 (2018) 095015 [arXiv:1607.08517] [INSPIRE].
S. De Curtis, L. Delle Rose, S. Moretti and K. Yagyu, A concrete composite 2-Higgs doublet model, JHEP 12 (2018) 051 [arXiv:1810.06465] [INSPIRE].
S. Kanemura, T. Kubota and E. Takasugi, Lee-Quigg-Thacker bounds for Higgs boson masses in a two doublet model, Phys. Lett. B 313 (1993) 155 [hep-ph/9303263] [INSPIRE].
B. Gripaios, A. Pomarol, F. Riva and J. Serra, Beyond the minimal composite Higgs model, JHEP 04 (2009) 070 [arXiv:0902.1483] [INSPIRE].
J. Barnard, T. Gherghetta and T.S. Ray, UV descriptions of composite Higgs models without elementary scalars, JHEP 02 (2014) 002 [arXiv:1311.6562] [INSPIRE].
G. Ferretti and D. Karateev, Fermionic UV completions of composite Higgs models, JHEP 03 (2014) 077 [arXiv:1312.5330] [INSPIRE].
A. Belyaev et al., Di-boson signatures as standard candles for partial compositeness, JHEP 01 (2017) 094 [Erratum ibid. 12 (2017) 088] [arXiv:1610.06591] [INSPIRE].
K. Agashe, R. Contino, L. Da Rold and A. Pomarol, A custodial symmetry for Z b\( \overline{b} \), Phys. Lett. B 641 (2006) 62 [hep-ph/0605341] [INSPIRE].
A. De Simone, O. Matsedonskyi, R. Rattazzi and A. Wulzer, A first top partner hunter’s guide, JHEP 04 (2013) 004 [arXiv:1211.5663] [INSPIRE].
M. Bauer, M. Neubert and A. Thamm, Collider probes of axion-like particles, JHEP 12 (2017) 044 [arXiv:1708.00443] [INSPIRE].
N. Craig, A. Hook and S. Kasko, The photophobic ALP, JHEP 09 (2018) 028 [arXiv:1805.06538] [INSPIRE].
ATLAS collaboration, Search for new phenomena in high-mass diphoton final states using 37 fb−1 of proton-proton collisions collected at \( \sqrt{s} \) = 13 TeV with the ATLAS detector, Phys. Lett. B 775 (2017) 105 [arXiv:1707.04147] [INSPIRE].
CMS collaboration, Search for Standard Model production of four top quarks with same-sign and multilepton final states in proton-proton collisions at \( \sqrt{s} \) = 13 TeV, Eur. Phys. J. C 78 (2018) 140 [arXiv:1710.10614] [INSPIRE].
J. Alwall et al., The automated computation of tree-level and next-to-leading order differential cross sections and their matching to parton shower simulations, JHEP 07 (2014) 079 [arXiv:1405.0301] [INSPIRE].
C. Degrande, C. Duhr, B. Fuks, D. Grellscheid, O. Mattelaer and T. Reiter, UFO — the Universal FeynRules Output, Comput. Phys. Commun. 183 (2012) 1201 [arXiv:1108.2040] [INSPIRE].
T. Sjöstrand et al., An introduction to PYTHIA 8.2, Comput. Phys. Commun. 191 (2015) 159 [arXiv:1410.3012] [INSPIRE].
DELPHES 3 collaboration, DELPHES 3, a modular framework for fast simulation of a generic collider experiment, JHEP 02 (2014) 057 [arXiv:1307.6346] [INSPIRE].
NNPDF collaboration, Parton distributions from high-precision collider data, Eur. Phys. J. C 77 (2017) 663 [arXiv:1706.00428] [INSPIRE].
A. Buckley et al., LHAPDF6: parton density access in the LHC precision era, Eur. Phys. J. C 75 (2015) 132 [arXiv:1412.7420] [INSPIRE].
E. Conte, B. Fuks and G. Serret, MadAnalysis 5, a user-friendly framework for collider phenomenology, Comput. Phys. Commun. 184 (2013) 222 [arXiv:1206.1599] [INSPIRE].
E. Conte and B. Fuks, Confronting new physics theories to LHC data with MADANALYSIS 5, Int. J. Mod. Phys. A 33 (2018) 1830027 [arXiv:1808.00480] [INSPIRE].
M. Aliev, H. Lacker, U. Langenfeld, S. Moch, P. Uwer and M. Wiedermann, HATHOR: HAdronic Top and Heavy quarks crOss section calculatoR, Comput. Phys. Commun. 182 (2011) 1034 [arXiv:1007.1327] [INSPIRE].
M. Cacciari, G.P. Salam and G. Soyez, FastJet user manual, Eur. Phys. J. C 72 (2012) 1896 [arXiv:1111.6097] [INSPIRE].
M. Cacciari, G.P. Salam and G. Soyez, The anti-kt jet clustering algorithm, JHEP 04 (2008) 063 [arXiv:0802.1189] [INSPIRE].
A.D. Martin, W.J. Stirling, R.S. Thorne and G. Watt, Parton distributions for the LHC, Eur. Phys. J. C 63 (2009) 189 [arXiv:0901.0002] [INSPIRE].
M.L. Mangano, M. Moretti, F. Piccinini and M. Treccani, Matching matrix elements and shower evolution for top-quark production in hadronic collisions, JHEP 01 (2007) 013 [hep-ph/0611129] [INSPIRE].
ATLAS collaboration, Search for new phenomena in high-mass diphoton final states using 37 fb−1 of proton-proton collisions collected at \( \sqrt{s} \) = 13 TeV with the ATLAS detector, Phys. Lett. B 775 (2017) 105 [arXiv:1707.04147] [INSPIRE].
G. Bélanger, R.M. Godbole, L. Hartgring and I. Niessen, Top polarization in stop production at the LHC, JHEP 05 (2013) 167 [arXiv:1212.3526] [INSPIRE].
D. Barducci and L. Panizzi, Vector-like quarks coupling discrimination at the LHC and future hadron colliders, JHEP 12 (2017) 057 [arXiv:1710.02325] [INSPIRE].
ATLAS collaboration, Performance assumptions based on full simulation for an upgraded ATLAS detector at a High-Luminosity LHC, ATL-PHYS-PUB-2013-009, CERN, Geneva, Switzerland (2013).
T.P. Li and Y.Q. Ma, Analysis methods for results in gamma-ray astronomy, Astrophys. J. 272 (1983) 317 [INSPIRE].
R.D. Cousins, J.T. Linnemann and J. Tucker, 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, Nucl. Instrum. Meth. A 595 (2008) 480 [physics/0702156] [INSPIRE].
G. Cowan, K. Cranmer, E. Gross and O. Vitells, Asymptotic formulae for likelihood-based tests of new physics, Eur. Phys. J. C 71 (2011) 1554 [Erratum ibid. C 73 (2013) 2501] [arXiv:1007.1727] [INSPIRE].
G. Cowan, Some statistical tools for particle physics, in MPI seminar, (2016).
ATLAS collaboration, Searches for the Z γ decay mode of the Higgs boson and for new high-mass resonances in pp collisions at \( \sqrt{s} \) = 13 TeV with the ATLAS detector, JHEP 10 (2017) 112 [arXiv:1708.00212] [INSPIRE].
CMS collaboration, Search for Z γ resonances using leptonic and hadronic final states in proton-proton collisions at \( \sqrt{s} \) = 13 TeV, JHEP 09 (2018) 148 [arXiv:1712.03143] [INSPIRE].
ATLAS collaboration, Search for Higgs boson pair production in the γγW W ∗ channel using pp collision data recorded at \( \sqrt{s} \) = 13 TeV with the ATLAS detector, Eur. Phys. J. C 78 (2018) 1007 [arXiv:1807.08567] [INSPIRE].
ATLAS collaboration, Search for Higgs boson pair production in the γγb\( \overline{b} \)final state with 13 TeV pp collision data collected by the ATLAS experiment, JHEP 11 (2018) 040 [arXiv:1807.04873] [INSPIRE].
CMS collaboration, Search for physics beyond the Standard Model in high-mass diphoton events from proton-proton collisions at \( \sqrt{s} \) = 13 TeV, Phys. Rev. D 98 (2018) 092001 [arXiv:1809.00327] [INSPIRE].
D. Eriksson, J. Rathsman and O. Stål, 2HDMC: two-Higgs-doublet model calculator, Comput. Phys. Commun. 181 (2010) 833 [INSPIRE].
P. Bechtle et al., HiggsBounds-4: improved tests of extended Higgs sectors against exclusion bounds from LEP, the Tevatron and the LHC, Eur. Phys. J. C 74 (2014) 2693 [arXiv:1311.0055] [INSPIRE].
D. Buarque Franzosi, G. Cacciapaglia and A. Deandrea, Sigma-assisted low scale composite Goldstone-Higgs, Eur. Phys. J. C 80 (2020) 28 [arXiv:1809.09146] [INSPIRE].
ATLAS collaboration, Measurement of the photon identification efficiencies with the ATLAS detector using LHC run 2 data collected in 2015 and 2016, Eur. Phys. J. C 79 (2019) 205 [arXiv:1810.05087] [INSPIRE].
ATLAS collaboration, Electron efficiency measurements with the ATLAS detector using the 2015 LHC proton-proton collision data, ATLAS-CONF-2016-024, CERN, Geneva, Switzerland (2016).
ATLAS collaboration, Expected performance of the ATLAS b-tagging algorithms in run-2, ATL-PHYS-PUB-2015-022, CERN, Geneva, Switzerland (2015).
Open Access
This article is distributed under the terms of the Creative Commons Attribution License (CC-BY 4.0), which permits any use, distribution and reproduction in any medium, provided the original author(s) and source are credited
Author information
Authors and Affiliations
Corresponding author
Additional information
ArXiv ePrint: 1907.05929
Also at University of Southampton, Southampton, U.K. (Y.-B. Liu and L. Panizzi)
Also at Uppsala University, Uppsala, Sweden (S. Moretti)
Rights and permissions
This article is published under an open access license. Please check the 'Copyright Information' section either on this page or in the PDF for details of this license and what re-use is permitted. If your intended use exceeds what is permitted by the license or if you are unable to locate the licence and re-use information, please contact the Rights and Permissions team.
About this article
Cite this article
Benbrik, R., Kuutmann, E.B., Franzosi, D.B. et al. Signatures of vector-like top partners decaying into new neutral scalar or pseudoscalar bosons. J. High Energ. Phys. 2020, 28 (2020). https://doi.org/10.1007/JHEP05(2020)028
Received:
Revised:
Accepted:
Published:
DOI: https://doi.org/10.1007/JHEP05(2020)028