Exotic Higgs decays in Type-II 2HDMs at the LHC and future 100 TeV hadron colliders

  • Felix Kling
  • Honglei LiEmail author
  • Adarsh Pyarelal
  • Huayang Song
  • Shufang Su
Open Access
Regular Article - Theoretical Physics


The exotic decay modes of non-Standard Model (SM) Higgses in models with extended Higgs sectors have the potential to serve as powerful search channels to explore the space of Two-Higgs Doublet Models (2HDMs). Once kinematically allowed, heavy Higgses could decay into pairs of light non-SM Higgses, or a non-SM Higgs and a SM gauge boson, with branching fractions that quickly dominate those of the conventional decay modes to SM particles. In this study, we focus on the prospects of probing Type-II 2HDMs at the LHC and a future 100 TeV pp collider via exotic decay channels. We study the three prominent exotic decay channels: AHZ, AH±W and H±HW±, and find that a 100-TeV pp collider can probe most of the region of the Type-II 2HDM parameter space that survives current theoretical and experimental constraints with sizable exotic decay branching fraction through these channels, making them complementary to the conventional decay channels for heavy non-SM Higgses.


Beyond Standard Model Higgs Physics 


Open Access

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  1. [1]
    ATLAS collaboration, Observation of a new particle in the search for the Standard Model Higgs boson with the ATLAS detector at the LHC, Phys. Lett. B 716 (2012) 1 [arXiv:1207.7214] [INSPIRE].
  2. [2]
    CMS collaboration, Observation of a new boson at a mass of 125 GeV with the CMS experiment at the LHC, Phys. Lett. B 716 (2012) 30 [arXiv:1207.7235] [INSPIRE].
  3. [3]
    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].ADSCrossRefGoogle Scholar
  4. [4]
    J. Gu, H. Li, Z. Liu, S. Su and W. Su, Learning from Higgs Physics at Future Higgs Factories, JHEP 12 (2017) 153 [arXiv:1709.06103] [INSPIRE].ADSCrossRefGoogle Scholar
  5. [5]
    N. Chen, T. Han, S. Su, W. Su and Y. Wu, Type-II 2HDM under the Precision Measurements at the Z-pole and a Higgs Factory, JHEP 03 (2019) 023 [arXiv:1808.02037] [INSPIRE].ADSCrossRefGoogle Scholar
  6. [6]
    CEPC-SPPC Study Group, CEPC-SPPC Preliminary Conceptual Design Report. 1. Physics and Detector, (2015).Google Scholar
  7. [7]
    M. Benedikt and F. Zimmermann, Future Circular Collider Study, Status and Progress, ap.pdf (2017).Google Scholar
  8. [8]
    B. Coleppa, F. Kling and S. Su, Exotic Decays Of A Heavy Neutral Higgs Through HZ/AZ Channel, JHEP 09 (2014) 161 [arXiv:1404.1922] [INSPIRE].ADSGoogle Scholar
  9. [9]
    T. Li and S. Su, Exotic Higgs Decay via Charged Higgs, JHEP 11 (2015) 068 [arXiv:1504.04381] [INSPIRE].ADSCrossRefGoogle Scholar
  10. [10]
    B. Coleppa, F. Kling and S. Su, Charged Higgs search via AW ± /HW ± channel, JHEP 12 (2014) 148 [arXiv:1408.4119] [INSPIRE].ADSCrossRefGoogle Scholar
  11. [11]
    F. Kling, A. Pyarelal and S. Su, Light Charged Higgs Bosons to AW/HW via Top Decay, JHEP 11 (2015) 051 [arXiv:1504.06624] [INSPIRE].ADSCrossRefGoogle Scholar
  12. [12]
    F. Kling, J.M. No and S. Su, Anatomy of Exotic Higgs Decays in 2HDM, JHEP 09 (2016) 093 [arXiv:1604.01406] [INSPIRE].
  13. [13]
    ATLAS collaboration, Search for a heavy Higgs boson decaying into a Z boson and another heavy Higgs boson in the ℓℓbb final state in pp collisions at \( \sqrt{s} \) = 13 TeV with the ATLAS detector, Phys. Lett. B 783 (2018) 392 [arXiv:1804.01126] [INSPIRE].
  14. [14]
    CMS collaboration, Search for neutral resonances decaying into a Z boson and a pair of b jets or τ leptons, Phys. Lett. B 759 (2016) 369 [arXiv:1603.02991] [INSPIRE].
  15. [15]
    ATLAS collaboration, Search for heavy resonances decaying into a W or Z boson and a Higgs boson in final states with leptons and b-jets in 36 fb −1 of \( \sqrt{s} \) = 13 TeV pp collisions with the ATLAS detector, JHEP 03 (2018) 174 [Erratum ibid. 11 (2018) 051] [arXiv:1712.06518] [INSPIRE].
  16. [16]
    ATLAS collaboration, Search for Higgs boson pair production in the \( \gamma \gamma b\overline{b} \) final state with 13 TeV pp collision data collected by the ATLAS experiment, JHEP 11 (2018) 040 [arXiv:1807.04873] [INSPIRE].
  17. [17]
    CMS collaboration, Search for Higgs boson pair production in the \( \gamma \gamma b\overline{b} \) final state in pp collisions at \( \sqrt{s} \) = 13 TeV, Phys. Lett. B 788 (2019) 7 [arXiv:1806.00408] [INSPIRE].
  18. [18]
    M. Benedikt et al., Future Circular Collider, CERN-ACC-2018-0058 (2018).
  19. [19]
    T. Plehn, M. Spannowsky, M. Takeuchi and D. Zerwas, Stop Reconstruction with Tagged Tops, JHEP 10 (2010) 078 [arXiv:1006.2833] [INSPIRE].ADSCrossRefGoogle Scholar
  20. [20]
    T. Plehn, M. Spannowsky and M. Takeuchi, How to Improve Top Tagging, Phys. Rev. D 85 (2012) 034029 [arXiv:1111.5034] [INSPIRE].ADSGoogle Scholar
  21. [21]
    F. Kling, T. Plehn and M. Takeuchi, Tagging single Tops, Phys. Rev. D 86 (2012) 094029 [arXiv:1207.4787] [INSPIRE].ADSGoogle Scholar
  22. [22]
    D.E. Kaplan, K. Rehermann, M.D. Schwartz and B. Tweedie, Top Tagging: A Method for Identifying Boosted Hadronically Decaying Top Quarks, Phys. Rev. Lett. 101 (2008) 142001 [arXiv:0806.0848] [INSPIRE].ADSCrossRefGoogle Scholar
  23. [23]
    J. Thaler and K. Van Tilburg, Maximizing Boosted Top Identification by Minimizing N-subjettiness, JHEP 02 (2012) 093 [arXiv:1108.2701] [INSPIRE].ADSCrossRefGoogle Scholar
  24. [24]
    G. Kasieczka, T. Plehn, M. Russell and T. Schell, Deep-learning Top Taggers or The End of QCD?, JHEP 05 (2017) 006 [arXiv:1701.08784] [INSPIRE].ADSCrossRefGoogle Scholar
  25. [25]
    K. Kondo, Dynamical Likelihood Method for Reconstruction of Events With Missing Momentum. 1: Method and Toy Models, J. Phys. Soc. Jap. 57 (1988) 4126 [INSPIRE].
  26. [26]
    J.S. Gainer, J. Lykken, K.T. Matchev, S. Mrenna and M. Park, The Matrix Element Method: Past, Present and Future, in Proceedings, 2013 Community Summer Study on the Future of U.S. Particle Physics: Snowmass on the Mississippi (CSS2013), Minneapolis, MN, U.S.A., July 29-August 6, 2013 (2013) [arXiv:1307.3546] [INSPIRE].
  27. [27]
    J. Brehmer, K. Cranmer, F. Kling and T. Plehn, Better Higgs boson measurements through information geometry, Phys. Rev. D 95 (2017) 073002 [arXiv:1612.05261] [INSPIRE].ADSMathSciNetGoogle Scholar
  28. [28]
    J. Brehmer, F. Kling, T. Plehn and T.M.P. Tait, Better Higgs-CP Tests Through Information Geometry, Phys. Rev. D 97 (2018) 095017 [arXiv:1712.02350] [INSPIRE].ADSGoogle Scholar
  29. [29]
    F. Kling, Exotic Higgs Decays, Ph.D. Thesis, Arizona U. (2016) [INSPIRE].
  30. [30]
    A. Pyarelal, Hidden Higgses and Dark Matter at Current and Future Colliders, Ph.D. Thesis, Arizona U. (2017) [INSPIRE].
  31. [31]
    B. Coleppa, F. Kling and S. Su, Constraining Type II 2HDM in Light of LHC Higgs Searches, JHEP 01 (2014) 161 [arXiv:1305.0002] [INSPIRE].ADSGoogle Scholar
  32. [32]
    ATLAS and CMS collaborations, Measurements of the Higgs boson production and decay rates and constraints on its couplings from a combined ATLAS and CMS analysis of the LHC pp collision data at \( \sqrt{s} \) = 7 and 8 TeV, JHEP 08 (2016) 045 [arXiv:1606.02266] [INSPIRE].
  33. [33]
    J.F. Gunion and H.E. Haber, The CP conserving two Higgs doublet model: The Approach to the decoupling limit, Phys. Rev. D 67 (2003) 075019 [hep-ph/0207010] [INSPIRE].
  34. [34]
    I.F. Ginzburg and I.P. Ivanov, Tree-level unitarity constraints in the most general 2HDM, Phys. Rev. D 72 (2005) 115010 [hep-ph/0508020] [INSPIRE].
  35. [35]
    J. Haller, A. Hoecker, R. Kogler, K. Mönig, T. Peiffer and J. Stelzer, Update of the global electroweak fit and constraints on two-Higgs-doublet models, Eur. Phys. J. C 78 (2018) 675 [arXiv:1803.01853] [INSPIRE].ADSCrossRefGoogle Scholar
  36. [36]
    HFLAV collaboration, Averages of b-hadron, c-hadron and τ -lepton properties as of summer 2016, Eur. Phys. J. C 77 (2017) 895 [arXiv:1612.07233] [INSPIRE].
  37. [37]
    M. Misiak and M. Steinhauser, Weak radiative decays of the B meson and bounds on M H± in the Two-Higgs-Doublet Model, Eur. Phys. J. C 77 (2017) 201 [arXiv:1702.04571] [INSPIRE].ADSCrossRefGoogle Scholar
  38. [38]
    T. Han, T. Li, S. Su and L.-T. Wang, Non-Decoupling MSSM Higgs Sector and Light Superpartners, JHEP 11 (2013) 053 [arXiv:1306.3229] [INSPIRE].ADSCrossRefGoogle Scholar
  39. [39]
    ALEPH, DELPHI, L3, OPAL and LEP collaborations, Search for Charged Higgs bosons: Combined Results Using LEP Data, Eur. Phys. J. C 73 (2013) 2463 [arXiv:1301.6065] [INSPIRE].
  40. [40]
    ALEPH, DELPHI, L3 and OPAL collaborations, LEP Working Group for Higgs Boson Searches, Search for neutral MSSM Higgs bosons at LEP, Eur. Phys. J. C 47 (2006) 547 [hep-ex/0602042] [INSPIRE].
  41. [41]
    ATLAS collaboration, Search for charged Higgs bosons decaying into top and bottom quarks at \( \sqrt{s} \) = 13 TeV with the ATLAS detector, JHEP 11 (2018) 085 [arXiv:1808.03599] [INSPIRE].
  42. [42]
    ATLAS collaboration, Search for charged Higgs bosons decaying via H ±τ ± ν τ in the τ +jets and τ +lepton final states with 36 fb −1 of pp collision data recorded at \( \sqrt{s} \) = 13 TeV with the ATLAS experiment, JHEP 09 (2018) 139 [arXiv:1807.07915] [INSPIRE].
  43. [43]
    CMS collaboration, Search for charged Higgs bosons with the H±τ ± ν τ decay channel in the fully hadronic final state at \( \sqrt{s} \) = 13 TeV, CMS-PAS-HIG-16-031 (2016).
  44. [44]
    A.G. Akeroyd et al., Prospects for charged Higgs searches at the LHC, Eur. Phys. J. C 77 (2017) 276 [arXiv:1607.01320] [INSPIRE].ADSCrossRefGoogle Scholar
  45. [45]
    R.V. Harlander, S. Liebler and H. Mantler, SusHi: A program for the calculation of Higgs production in gluon fusion and bottom-quark annihilation in the Standard Model and the MSSM, Comput. Phys. Commun. 184 (2013) 1605 [arXiv:1212.3249] [INSPIRE].ADSCrossRefzbMATHGoogle Scholar
  46. [46]
    R.V. Harlander and W.B. Kilgore, Next-to-next-to-leading order Higgs production at hadron colliders, Phys. Rev. Lett. 88 (2002) 201801 [hep-ph/0201206] [INSPIRE].
  47. [47]
    R.V. Harlander and W.B. Kilgore, Higgs boson production in bottom quark fusion at next-to-next-to leading order, Phys. Rev. D 68 (2003) 013001 [hep-ph/0304035] [INSPIRE].
  48. [48]
    J. Hajer, A. Ismail, F. Kling, Y.-Y. Li, T. Liu and S. Su, Searches for non-SM heavy Higgses at a 100 TeV pp collider, Int. J. Mod. Phys. A 30 (2015) 1544005 [INSPIRE].ADSCrossRefGoogle Scholar
  49. [49]
    W. Beenakker, R. Hopker and M. Spira, PROSPINO: A Program for the production of supersymmetric particles in next-to-leading order QCD, hep-ph/9611232 [INSPIRE].
  50. [50]
    T. Plehn, Charged Higgs boson production in bottom gluon fusion, Phys. Rev. D 67 (2003) 014018 [hep-ph/0206121] [INSPIRE].
  51. [51]
    CMS collaboration, Search for additional neutral MSSM Higgs bosons in the ττ final state in proton-proton collisions at \( \sqrt{s} \) = 13 TeV, JHEP 09 (2018) 007 [arXiv:1803.06553] [INSPIRE].
  52. [52]
    ATLAS collaboration, Search for additional heavy neutral Higgs and gauge bosons in the ditau final state produced in 36 fb −1 of pp collisions at \( \sqrt{s} \) = 13 TeV with the ATLAS detector, JHEP 01 (2018) 055 [arXiv:1709.07242] [INSPIRE].
  53. [53]
    D. Dicus, A. Stange and S. Willenbrock, Higgs decay to top quarks at hadron colliders, Phys. Lett. B 333 (1994) 126 [hep-ph/9404359] [INSPIRE].
  54. [54]
    S. Jung, J. Song and Y.W. Yoon, Dip or nothingness of a Higgs resonance from the interference with a complex phase, Phys. Rev. D 92 (2015) 055009 [arXiv:1505.00291] [INSPIRE].ADSGoogle Scholar
  55. [55]
    M. Carena and Z. Liu, Challenges and opportunities for heavy scalar searches in the \( t\overline{t} \) channel at the LHC, JHEP 11 (2016) 159 [arXiv:1608.07282] [INSPIRE].
  56. [56]
    ATLAS collaboration, Search for Heavy Higgs Bosons A/H Decaying to a Top Quark Pair in pp Collisions at \( \sqrt{s} \) = 8 TeV with the ATLAS Detector, Phys. Rev. Lett. 119 (2017) 191803 [arXiv:1707.06025] [INSPIRE].
  57. [57]
    N. Craig, J. Hajer, Y.-Y. Li, T. Liu and H. Zhang, Heavy Higgs bosons at low tan β: from the LHC to 100 TeV, JHEP 01 (2017) 018 [arXiv:1605.08744] [INSPIRE].ADSGoogle Scholar
  58. [58]
    J. Hajer, Y.-Y. Li, T. Liu and J.F.H. Shiu, Heavy Higgs Bosons at 14 TeV and 100 TeV, JHEP 11 (2015) 124 [arXiv:1504.07617] [INSPIRE].ADSCrossRefGoogle Scholar
  59. [59]
    A. Aboubrahim and P. Nath, Naturalness, the hyperbolic branch and prospects for the observation of charged Higgs bosons at high luminosity LHC and 27 TeV LHC, Phys. Rev. D 98 (2018) 095024 [arXiv:1810.12868] [INSPIRE].ADSGoogle Scholar
  60. [60]
    N. Craig, F. D’Eramo, P. Draper, S. Thomas and H. Zhang, The Hunt for the Rest of the Higgs Bosons, JHEP 06 (2015) 137 [arXiv:1504.04630] [INSPIRE].ADSCrossRefGoogle Scholar
  61. [61]
    M. Czakon, P. Fiedler and A. Mitov, Total Top-Quark Pair-Production Cross Section at Hadron Colliders Through O(α S4), Phys. Rev. Lett. 110 (2013) 252004 [arXiv:1303.6254] [INSPIRE].ADSCrossRefGoogle Scholar
  62. [62]
    M.L. Mangano et al., Physics at a 100 TeV pp Collider: Standard Model Processes, CERN Yellow Rep. (2017) 1 [arXiv:1607.01831] [INSPIRE].
  63. [63]
    F. Febres Cordero, L. Reina and D. Wackeroth, W- and Z-boson production with a massive bottom-quark pair at the Large Hadron Collider, Phys. Rev. D 80 (2009) 034015 [arXiv:0906.1923] [INSPIRE].ADSGoogle Scholar
  64. [64]
    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].ADSCrossRefGoogle Scholar
  65. [65]
    T. Sjöstrand, S. Mrenna and P.Z. Skands, PYTHIA 6.4 Physics and Manual, JHEP 05 (2006) 026 [hep-ph/0603175] [INSPIRE].
  66. [66]
    T. Sjöstrand et al., An Introduction to PYTHIA 8.2, Comput. Phys. Commun. 191 (2015) 159 [arXiv:1410.3012] [INSPIRE].
  67. [67]
    DELPHES 3 collaboration, DELPHES 3, A modular framework for fast simulation of a generic collider experiment, JHEP 02 (2014) 057 [arXiv:1307.6346] [INSPIRE].
  68. [68]
    D. Eriksson, J. Rathsman and O. Stal, 2HDMC: Two-Higgs-Doublet Model Calculator Physics and Manual, Comput. Phys. Commun. 181 (2010) 189 [arXiv:0902.0851] [INSPIRE].ADSCrossRefzbMATHGoogle Scholar
  69. [69]
    F. Cascioli et al., ZZ production at hadron colliders in NNLO QCD, Phys. Lett. B 735 (2014) 311 [arXiv:1405.2219] [INSPIRE].ADSCrossRefGoogle Scholar
  70. [70]
    CMS collaboration, Top Tagging with New Approaches, CMS-PAS-JME-15-002 (2016).Google Scholar
  71. [71]
    ATLAS collaboration, Differential top-antitop cross-section measurements as a function of observables constructed from final-state particles using pp collisions at \( \sqrt{s} \) = 7 TeV in the ATLAS detector, JHEP 06 (2015) 100 [arXiv:1502.05923] [INSPIRE].
  72. [72]
    J. Li, R. Patrick, P. Sharma and A.G. Williams, Boosting the charged Higgs search prospects using jet substructure at the LHC, JHEP 11 (2016) 164 [arXiv:1609.02645] [INSPIRE].ADSCrossRefGoogle Scholar
  73. [73]
    R. Patrick, P. Sharma and A.G. Williams, Triple top signal as a probe of charged Higgs in a 2HDM, Phys. Lett. B 780 (2018) 603 [arXiv:1710.08086] [INSPIRE].ADSCrossRefGoogle Scholar
  74. [74]
    J. Alwall, M. Herquet, F. Maltoni, O. Mattelaer and T. Stelzer, MadGraph 5: Going Beyond, JHEP 06 (2011) 128 [arXiv:1106.0522] [INSPIRE].ADSCrossRefzbMATHGoogle Scholar
  75. [75]
    C. Degrande, Automatic evaluation of UV and R2 terms for beyond the Standard Model Lagrangians: a proof-of-principle, Comput. Phys. Commun. 197 (2015) 239 [arXiv:1406.3030] [INSPIRE].ADSMathSciNetCrossRefzbMATHGoogle Scholar
  76. [76]
    FCC-hh Working Group, FCC Pythia + Delphes Analysis (Documentation),
  77. [77]
    H.-J. Yang, B.P. Roe and J. Zhu, Studies of boosted decision trees for MiniBooNE particle identification, Nucl. Instrum. Meth. A 555 (2005) 370 [physics/0508045] [INSPIRE].
  78. [78]
    A. Hocker et al., TMVAToolkit for Multivariate Data Analysis, PoS(ACAT)040 [physics/0703039] [INSPIRE].
  79. [79]
    N. Kumar and S.P. Martin, Vectorlike Leptons at the Large Hadron Collider, Phys. Rev. D 92 (2015) 115018 [arXiv:1510.03456] [INSPIRE].ADSGoogle Scholar
  80. [80]
    G. Cowan, Two developments in tests for discovery: use of weighted Monte Carlo events and an improved measure, Progress on Statistical Issues in Searches, SLAC, June 4-6, 2012.Google Scholar
  81. [81]
    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].
  82. [82]
    M. Backović and J. Juknevich, TemplateTagger v1.0.0: A Template Matching Tool for Jet Substructure, Comput. Phys. Commun. 185 (2014) 1322 [arXiv:1212.2978] [INSPIRE].
  83. [83]
    T. Plehn and M. Spannowsky, Top Tagging, J. Phys. G 39 (2012) 083001 [arXiv:1112.4441] [INSPIRE].ADSCrossRefGoogle Scholar
  84. [84]
    G. Kasieczka, T. Plehn, T. Schell, T. Strebler and G.P. Salam, Resonance Searches with an Updated Top Tagger, JHEP 06 (2015) 203 [arXiv:1503.05921] [INSPIRE].ADSCrossRefGoogle Scholar
  85. [85]
    J. Pearkes, W. Fedorko, A. Lister and C. Gay, Jet Constituents for Deep Neural Network Based Top Quark Tagging, arXiv:1704.02124 [INSPIRE].
  86. [86]
    Y.L. Dokshitzer, G.D. Leder, S. Moretti and B.R. Webber, Better jet clustering algorithms, JHEP 08 (1997) 001 [hep-ph/9707323] [INSPIRE].
  87. [87]
    M. Cacciari, G.P. Salam and G. Soyez, FastJet User Manual, Eur. Phys. J. C 72 (2012) 1896 [arXiv:1111.6097] [INSPIRE].ADSCrossRefzbMATHGoogle Scholar
  88. [88]
    A.J. Larkoski, S. Marzani, G. Soyez and J. Thaler, Soft Drop, JHEP 05 (2014) 146 [arXiv:1402.2657] [INSPIRE].ADSCrossRefGoogle Scholar

Copyright information

© The Author(s) 2019

Authors and Affiliations

  • Felix Kling
    • 1
  • Honglei Li
    • 2
    Email author
  • Adarsh Pyarelal
    • 3
  • Huayang Song
    • 4
  • Shufang Su
    • 4
  1. 1.Department of Physics and AstronomyUniversity of CaliforniaIrvineU.S.A.
  2. 2.School of Physics and TechnologyUniversity of JinanJinanChina
  3. 3.School of InformationUniversity of ArizonaTucsonU.S.A.
  4. 4.Department of PhysicsUniversity of ArizonaTucsonU.S.A.

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