Exploring the heavy quark sector of the Bestest Little Higgs model at the LHC

  • Stephen Godfrey
  • Thomas Grégoire
  • Pat Kalyniak
  • Travis A. W. Martin
  • Kenneth Moats


We present discovery limits for heavy quarks in the Bestest Little Higgs model via pair production at the LHC running at \( \sqrt {s} = 7\;{\text{TeV}} \). We study pair produced heavy toplike quarks decaying to \( b\overline b {W^{ + }}{W^{ - }} \) and \( t\overline t ZZ \) final states and singly produced heavy top-like quarks via t-channel W exchange. These results are compared to currently available limits on heavy top-like quark cross sections from CMS (with 1.14 fb−1 integrated luminosity) for two scenarios of Yukawa couplings. We find that the CMS data limits the mass of the lightest top partner to larger than 413 GeV in the first scenario, where the two lightest top-partners have a small mass splitting, and 364 GeV in the second scenario, where the mass splitting between the two lightest top-partners is larger.


Phenomenological Models Hadronic Colliders 


  1. [1]
    CMS collaboration, S. Chatrchyan et al., Search for Supersymmetry at the LHC in Events with Jets and Missing Transverse Energy, Phys. Rev. Lett. 107 (2011) 221804 [arXiv:1109.2352] [INSPIRE].ADSCrossRefGoogle Scholar
  2. [2]
    ATLAS collaboration, G. Aad et al., Search for new phenomena in final states with large jet multiplicities and missing transverse momentum using \( \sqrt {s} = 7\;TeV \) pp collisions with the ATLAS detector, JHEP 11 (2011) 099 [arXiv:1110.2299] [INSPIRE].ADSCrossRefGoogle Scholar
  3. [3]
    J.A. Conley, J.S. Gainer, J.L. Hewett, M.P. Le and T.G. Rizzo, Supersymmetry Without Prejudice at the 7 TeV LHC, Phys. Rev. D (2011) [arXiv:1103.1697] [INSPIRE].
  4. [4]
    M. Papucci, J.T. Ruderman and A. Weiler, Natural SUSY Endures, arXiv:1110.6926 [INSPIRE].
  5. [5]
    N. Arkani-Hamed, A.G. Cohen and H. Georgi, Electroweak symmetry breaking from dimensional deconstruction, Phys. Lett. B 513 (2001) 232 [hep-ph/0105239] [INSPIRE].MathSciNetADSGoogle Scholar
  6. [6]
    N. Arkani-Hamed, A.G. Cohen, T. Gregoire and J.G. Wacker, Phenomenology of electroweak symmetry breaking from theory space, JHEP 08 (2002) 020 [hep-ph/0202089] [INSPIRE].MathSciNetADSGoogle Scholar
  7. [7]
    N. Arkani-Hamed et al., The Minimal moose for a little Higgs, JHEP 08 (2002) 021 [hep-ph/0206020] [INSPIRE].MathSciNetADSCrossRefGoogle Scholar
  8. [8]
    N. Arkani-Hamed, A. Cohen, E. Katz and A. Nelson, The Littlest Higgs, JHEP 07 (2002) 034 [hep-ph/0206021] [INSPIRE].MathSciNetADSCrossRefGoogle Scholar
  9. [9]
    C. Csáki, J. Hubisz, G.D. Kribs, P. Meade and J. Terning, Big corrections from a little Higgs, Phys. Rev. D 67 (2003) 115002 [hep-ph/0211124] [INSPIRE].ADSGoogle Scholar
  10. [10]
    C. Csáki, J. Hubisz, G.D. Kribs, P. Meade and J. Terning, Variations of little Higgs models and their electroweak constraints, Phys. Rev. D 68 (2003) 035009 [hep-ph/0303236] [INSPIRE].ADSGoogle Scholar
  11. [11]
    R. Diener, S. Godfrey and T.A. Martin, Unravelling an Extra Neutral Gauge Boson at the LHC using Third Generation Fermions, Phys. Rev. D 83 (2011) 115008 [arXiv:1006.2845] [INSPIRE].ADSGoogle Scholar
  12. [12]
    ATLAS collaboration, G. Aad et al., Search for dilepton resonances in pp collisions at \( \sqrt {s} = 7\;TeV \) with the ATLAS detector,Phys. Rev. Lett. 107 (2011) 272002 [arXiv:1108.1582] [INSPIRE].ADSCrossRefGoogle Scholar
  13. [13]
    J. Casas, J.R. Espinosa and I. Hidalgo, Implications for new physics from fine-tuning arguments. II. Little Higgs models, JHEP 03 (2005) 038 [hep-ph/0502066] [INSPIRE].ADSCrossRefGoogle Scholar
  14. [14]
    M. Schmaltz, D. Stolarski and J. Thaler, The Bestest Little Higgs, JHEP 09 (2010) 018 [arXiv:1006.1356] [INSPIRE].ADSCrossRefGoogle Scholar
  15. [15]
    G. Azuelos et al., Exploring little Higgs models with ATLAS at the LHC, Eur. Phys. J. C 39S2 (2005) 13 [hep-ph/0402037] [INSPIRE].ADSCrossRefGoogle Scholar
  16. [16]
    J. Rathsman and O. Stal, 2HDMC - a two Higgs Doublet Model Calculator, PoS(CHARGED2010)034 [arXiv:1104.5563] [INSPIRE].
  17. [17]
    W. Altmannshofer and D.M. Straub, Viability of MSSM scenarios at very large tan β, JHEP 09 (2010) 078 [arXiv:1004.1993] [INSPIRE].ADSCrossRefGoogle Scholar
  18. [18]
    The CMS collaboration, Combination of SM Higgs Searches, CMS-PAS-HIG-11-032.Google Scholar
  19. [19]
    ATLAS collaboration, Combination of Higgs Boson Searches with up to 4.9 fb-1 of pp Collisions Data Taken at a center-of-mass energy of 7 TeV with the ATLAS Experiment at the LHC, ATLAS-CONF-2011-163 (2011).
  20. [20]
    G. Cacciapaglia et al., Heavy Vector-like Top Partners at the LHC and flavour constraints, arXiv:1108.6329 [INSPIRE].
  21. [21]
    A.J. Buras, A. Poschenrieder and S. Uhlig, Particle-antiparticle mixing, epsilon(K) and the unitarity triangle in the littlest Higgs model, Nucl. Phys. B 716 (2005) 173 [hep-ph/0410309] [INSPIRE].ADSCrossRefGoogle Scholar
  22. [22]
    M. Blanke and A.J. Buras, A Guide to Flavour Changing Neutral Currents in the Littlest Higgs Model with T Parity, Acta Phys. Polon. B 38 (2007) 2923 [hep-ph/0703117] [INSPIRE].ADSGoogle Scholar
  23. [23]
    A. Atre et al., Model-Independent Searches for New Quarks at the LHC, JHEP 08 (2011) 080 [arXiv:1102.1987] [INSPIRE].ADSCrossRefGoogle Scholar
  24. [24]
    The CMS collaboration, Search for a Heavy Top-like Quark in the Dilepton Final State in pp Collisions at \( \sqrt {s} = 7\;TeV \), CMS PAS EXO-11-050.Google Scholar
  25. [25]
    CMS collaboration, S. Chatrchyan et al., Search for a Vector-like Quark with Charge 2/3 in t+ Z Events from pp Collisions at \( \sqrt {s} = 7\;TeV \), Phys. Rev. Lett. 107 (2011) 271802 [arXiv:1109.4985] [INSPIRE].ADSCrossRefGoogle Scholar
  26. [26]
    The CMS Collaboration, Search for a Top-like Quark Decaying To A Top Quark And a Z boson in pp Collisions at \( \sqrt {s} = 7\;TeV \), CMS PAS EXO-11-005.Google Scholar
  27. [27]
    E.L. Berger and Q.-H. Cao, Next-to-Leading Order Cross sections for New Heavy Fermion Production at Hadron Colliders, Phys. Rev. D 81 (2010) 035006 [arXiv:0909.3555] [INSPIRE].ADSGoogle Scholar
  28. [28]
    D. Stump et al., Inclusive jet production, parton distributions and the search for new physics, JHEP 10 (2003) 046 [hep-ph/0303013] [INSPIRE].ADSCrossRefGoogle Scholar
  29. [29]
    P. Meade and M. Reece, BRIDGE: Branching ratio inquiry/decay generated events, hep-ph/0703031 [INSPIRE].
  30. [30]
    ATLAS collaboration, Search for Fourth Generation Quarks Decaying to WqWq → ll νν q q in pp collisions at \( \sqrt {s} = 7\;TeV \) with the ATLAS Detector, ATLAS-CONF-2011-022 (2011).
  31. [31]
    T. Han, H.E. Logan, B. McElrath and L.-T. Wang, Phenomenology of the little Higgs model, Phys. Rev. D 67 (2003) 095004 [hep-ph/0301040] [INSPIRE].ADSGoogle Scholar
  32. [32]
    J. Alwall, M. Herquet, F. Maltoni, O. Mattelaer and T. Stelzer, MadGraph 5 : Going Beyond, JHEP 06 (2011) 128 [arXiv:1106.0522] [INSPIRE].ADSCrossRefGoogle Scholar
  33. [33]
    J.M. Campbell, R. Frederix, F. Maltoni and F. Tramontano, NLO predictions for t-channel production of single top and fourth generation quarks at hadron colliders, JHEP 10 (2009) 042 [arXiv:0907.3933] [INSPIRE].ADSCrossRefGoogle Scholar
  34. [34]
    ATLAS collaboration, Measurement of the t-channel Single Top-Quark Production Cross section in 0.70f b −1 of pp Collisions at \( \sqrt {s} = 7\;TeV \) with the ATLAS detector, ATLAS-CONF-2011-101 (2011).

Copyright information

© SISSA, Trieste, Italy 2012

Authors and Affiliations

  • Stephen Godfrey
    • 1
  • Thomas Grégoire
    • 1
  • Pat Kalyniak
    • 1
  • Travis A. W. Martin
    • 1
  • Kenneth Moats
    • 1
  1. 1.Ottawa-Carleton Institute for Physics, Department of PhysicsCarleton UniversityOttawaCanada

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