A 125 GeV composite Higgs boson versus flavour and electroweak precision tests

  • Riccardo Barbieri
  • Dario ButtazzoEmail author
  • Filippo Sala
  • David M. Straub
  • Andrea Tesi


A composite Higgs boson of 125 GeV mass, only mildly fine-tuned, requires top partners with a semi-perturbative coupling and a mass not greater than about a TeV. We analyze the strong constraints on such picture arising from flavour and electroweak precision tests in models of partial compositeness. We consider different representations for the composite fermions and compare the case of an anarchic flavour structure to models with a U(3)3 and U(2)3 flavour symmetry. Although non trivially, some models emerge that look capable of accommodating a 125GeV Higgs boson with top partners in an interesting mass range for discovery at the LHC as well as associated flavour signals.


Beyond Standard Model Technicolor and Composite Models Heavy Quark Physics CP violation 


  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].ADSGoogle Scholar
  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].ADSGoogle Scholar
  3. [3]
    D.B. Kaplan and H. Georgi, SU(2) × U(1) Breaking by Vacuum Misalignment, Phys. Lett. B 136 (1984) 183 [INSPIRE].ADSGoogle Scholar
  4. [4]
    H. Georgi and D.B. Kaplan, Composite Higgs and custodial SU(2), Phys. Lett. B 145 (1984) 216 [INSPIRE].ADSGoogle Scholar
  5. [5]
    R. Contino, Y. Nomura and A. Pomarol, Higgs as a holographic pseudoGoldstone boson, Nucl. Phys. B 671 (2003) 148 [hep-ph/0306259] [INSPIRE].ADSCrossRefGoogle Scholar
  6. [6]
    K. Agashe, R. Contino and A. Pomarol, The minimal composite Higgs model, Nucl. Phys. B 719 (2005) 165 [hep-ph/0412089] [INSPIRE].ADSCrossRefGoogle Scholar
  7. [7]
    D.B. Kaplan, Flavor at SSC energies: a new mechanism for dynamically generated fermion masses, Nucl. Phys. B 365 (1991) 259 [INSPIRE].ADSCrossRefGoogle Scholar
  8. [8]
    R. Contino, L. Da Rold and A. Pomarol, Light custodians in natural composite Higgs models, Phys. Rev. D 75 (2007) 055014 [hep-ph/0612048] [INSPIRE].ADSGoogle Scholar
  9. [9]
    A. Pomarol and F. Riva, The composite Higgs and light resonance connection, JHEP 08 (2012) 135 [arXiv:1205.6434] [INSPIRE].ADSCrossRefGoogle Scholar
  10. [10]
    M. Redi and A. Tesi, Implications of a light Higgs in composite models, JHEP 10 (2012) 166 [arXiv:1205.0232] [INSPIRE].ADSCrossRefGoogle Scholar
  11. [11]
    O. Matsedonskyi, G. Panico and A. Wulzer, Light top partners for a light composite Higgs, JHEP 01 (2013) 164 [arXiv:1204.6333] [INSPIRE].ADSCrossRefGoogle Scholar
  12. [12]
    D. Marzocca, M. Serone and J. Shu, General composite Higgs models, JHEP 08 (2012) 013 [arXiv:1205.0770] [INSPIRE].ADSCrossRefGoogle Scholar
  13. [13]
    G. Panico, M. Redi, A. Tesi and A. Wulzer, On the tuning and the mass of the composite Higgs, JHEP 03 (2013) 051 [arXiv:1210.7114] [INSPIRE].ADSCrossRefGoogle Scholar
  14. [14]
    P.P. Giardino, K. Kannike, I. Masina, M. Raidal and A. Strumia, The universal Higgs fit, arXiv:1303.3570 [INSPIRE].
  15. [15]
    CMS collaboration, Search for heavy, top-like quark pair production in the dilepton final state in pp collisions at \( \sqrt{s}=7 \) TeV, Phys. Lett. B 716 (2012) 103 [arXiv:1203.5410] [INSPIRE].ADSGoogle Scholar
  16. [16]
    CMS collaboration, Search for pair produced fourth-generation up-type quarks in pp collisions at \( \sqrt{s}=7 \) TeV with a lepton in the final state, Phys. Lett. B 718 (2012) 307 [arXiv:1209.0471] [INSPIRE].ADSGoogle Scholar
  17. [17]
    CMS collaboration, Search for heavy quarks decaying into a top quark and a W or Z boson using lepton + jets events in pp collisions at \( \sqrt{s}=7 \) TeV, JHEP 01 (2013) 154 [arXiv:1210.7471] [INSPIRE].ADSGoogle Scholar
  18. [18]
    ATLAS collaboration, Search for exotic same-sign dilepton signatures (bquark, T 5/3 and four top quarks production) in 4.7/fb of pp collisions at \( \sqrt{s}=7 \) TeV with the ATLAS detector, ATLAS-CONF-2012-130 (2012).
  19. [19]
    R. Contino, T. Kramer, M. Son and R. Sundrum, Warped/composite phenomenology simplified, JHEP 05 (2007) 074 [hep-ph/0612180] [INSPIRE].ADSCrossRefGoogle Scholar
  20. [20]
    Y. Grossman and M. Neubert, Neutrino masses and mixings in nonfactorizable geometry, Phys. Lett. B 474 (2000) 361 [hep-ph/9912408] [INSPIRE].MathSciNetADSGoogle Scholar
  21. [21]
    S.J. Huber and Q. Shafi, Fermion masses, mixings and proton decay in a Randall-Sundrum model, Phys. Lett. B 498 (2001) 256 [hep-ph/0010195] [INSPIRE].ADSGoogle Scholar
  22. [22]
    T. Gherghetta and A. Pomarol, Bulk fields and supersymmetry in a slice of AdS, Nucl. Phys. B 586 (2000) 141 [hep-ph/0003129] [INSPIRE].MathSciNetADSCrossRefGoogle Scholar
  23. [23]
    K. Agashe, G. Perez and A. Soni, Flavor structure of warped extra dimension models, Phys. Rev. D 71 (2005) 016002 [hep-ph/0408134] [INSPIRE].ADSGoogle Scholar
  24. [24]
    M. Blanke, A.J. Buras, B. Duling, S. Gori and A. Weiler, ΔF = 2 observables and fine-tuning in a warped extra dimension with custodial protection, JHEP 03 (2009) 001 [arXiv:0809.1073] [INSPIRE].ADSCrossRefGoogle Scholar
  25. [25]
    M. Bauer, S. Casagrande, U. Haisch and M. Neubert, Flavor physics in the Randall-Sundrum model: II. Tree-level weak-interaction processes, JHEP 09 (2010) 017 [arXiv:0912.1625] [INSPIRE].ADSCrossRefGoogle Scholar
  26. [26]
    B. Keren-Zur et al., On partial compositeness and the CP asymmetry in charm decays, Nucl. Phys. B 867 (2013) 429 [arXiv:1205.5803] [INSPIRE].Google Scholar
  27. [27]
    C. Csáki, A. Falkowski and A. Weiler, The flavor of the composite pseudo-goldstone Higgs, JHEP 09 (2008) 008 [arXiv:0804.1954] [INSPIRE].ADSCrossRefGoogle Scholar
  28. [28]
    G. Cacciapaglia et al., A GIM mechanism from extra dimensions, JHEP 04 (2008) 006 [arXiv:0709.1714] [INSPIRE].ADSCrossRefGoogle Scholar
  29. [29]
    R. Barbieri, G. Isidori and D. Pappadopulo, Composite fermions in electroweak symmetry breaking, JHEP 02 (2009) 029 [arXiv:0811.2888] [INSPIRE].ADSCrossRefGoogle Scholar
  30. [30]
    M. Redi and A. Weiler, Flavor and CP invariant composite Higgs models, JHEP 11 (2011) 108 [arXiv:1106.6357] [INSPIRE].ADSCrossRefGoogle Scholar
  31. [31]
    R. Barbieri, G. Isidori, J. Jones-Perez, P. Lodone and D.M. Straub, U(2) and minimal flavour violation in supersymmetry, Eur. Phys. J. C 71 (2011) 1725 [arXiv:1105.2296] [INSPIRE].ADSCrossRefGoogle Scholar
  32. [32]
    R. Barbieri, D. Buttazzo, F. Sala and D.M. Straub, Flavour physics from an approximate U(2)3 symmetry, JHEP 07 (2012) 181 [arXiv:1203.4218] [INSPIRE].ADSCrossRefGoogle Scholar
  33. [33]
    R. Barbieri, B. Bellazzini, V.S. Rychkov and A. Varagnolo, The Higgs boson from an extended symmetry, Phys. Rev. D 76 (2007) 115008 [arXiv:0706.0432] [INSPIRE].ADSGoogle Scholar
  34. [34]
    M. Baak et al., The Electroweak fit of the standard model after the discovery of a new boson at the LHC, Eur. Phys. J. C 72 (2012) 2205 [arXiv:1209.2716] [INSPIRE].ADSGoogle Scholar
  35. [35]
    K. Agashe, R. Contino, L. Da Rold and A. Pomarol, A custodial symmetry for Zbb, Phys. Lett. B 641 (2006) 62 [hep-ph/0605341] [INSPIRE].ADSGoogle Scholar
  36. [36]
    N. Vignaroli, ΔF = 1 constraints on composite Higgs models with LR parity, Phys. Rev. D 86 (2012) 115011 [arXiv:1204.0478] [INSPIRE].ADSGoogle Scholar
  37. [37]
    W. Altmannshofer and D.M. Straub, Cornering new physics in bs transitions, JHEP 08 (2012) 121 [arXiv:1206.0273] [INSPIRE].ADSCrossRefGoogle Scholar
  38. [38]
    G. Isidori, J.F. Kamenik, Z. Ligeti and G. Perez, Implications of the LHCb Evidence for Charm CP-violation, Phys. Lett. B 711 (2012) 46 [arXiv:1111.4987] [INSPIRE].ADSGoogle Scholar
  39. [39]
    L. Calibbi, Z. Lalak, S. Pokorski and R. Ziegler, Universal constraints on low-energy flavour models, JHEP 07 (2012) 004 [arXiv:1204.1275] [INSPIRE].ADSCrossRefGoogle Scholar
  40. [40]
    A.J. Buras, C. Grojean, S. Pokorski and R. Ziegler, FCNC effects in a minimal theory of fermion masses, JHEP 08 (2011) 028 [arXiv:1105.3725] [INSPIRE].ADSCrossRefGoogle Scholar
  41. [41]
    K. Agashe, A. Azatov and L. Zhu, Flavor Violation Tests of Warped/Composite SM in the Two-Site Approach, Phys. Rev. D 79 (2009) 056006 [arXiv:0810.1016] [INSPIRE].ADSGoogle Scholar
  42. [42]
    O. Gedalia, G. Isidori and G. Perez, Combining Direct & Indirect Kaon CP-violation to Constrain the Warped KK Scale, Phys. Lett. B 682 (2009) 200 [arXiv:0905.3264] [INSPIRE].ADSGoogle Scholar
  43. [43]
    R. Barbieri, D. Buttazzo, F. Sala and D.M. Straub, Less minimal flavour violation, JHEP 10 (2012) 040 [arXiv:1206.1327] [INSPIRE].ADSCrossRefGoogle Scholar
  44. [44]
    ATLAS collaboration, Search for New Phenomena in the Dijet Mass Distribution using 5.8 fb 1 of pp Collisions at \( \sqrt{s}=8 \) TeV collected by the ATLAS Detector, ATLAS-CONF-2012-088 (2012).
  45. [45]
    CMS collaboration, Search for Narrow Resonances using the Dijet Mass Spectrum in pp Collisions at \( \sqrt{s} \) of 8 TeV, CMS-PAS-EXO-12-016 (2012).
  46. [46]
    M. Redi, Composite MFV and beyond, Eur. Phys. J. C 72 (2012) 2030 [arXiv:1203.4220] [INSPIRE].ADSGoogle Scholar
  47. [47]
    O. Domenech, A. Pomarol and J. Serra, Probing the SM with Dijets at the LHC, Phys. Rev. D 85 (2012) 074030 [arXiv:1201.6510] [INSPIRE].ADSGoogle Scholar
  48. [48]
    W. Altmannshofer et al., Symmetries and asymmetries of BK μ + μ decays in the Standard model and beyond, JHEP 01 (2009) 019 [arXiv:0811.1214] [INSPIRE].ADSCrossRefGoogle Scholar

Copyright information

© SISSA, Trieste, Italy 2013

Authors and Affiliations

  • Riccardo Barbieri
    • 1
  • Dario Buttazzo
    • 1
    Email author
  • Filippo Sala
    • 1
  • David M. Straub
    • 2
  • Andrea Tesi
    • 1
  1. 1.Scuola Normale Superiore and INFNPisaItaly
  2. 2.Institut für Physik (THEP)Johannes Gutenberg-UniversitätMainzGermany

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