The flavor-locked flavorful two Higgs doublet model

  • Wolfgang Altmannshofer
  • Stefania Gori
  • Dean J. RobinsonEmail author
  • Douglas Tuckler
Open Access
Regular Article - Theoretical Physics


We propose a new framework to generate the Standard Model (SM) quark flavor hierarchies in the context of two Higgs doublet models (2HDM). The ‘flavorful’ 2HDM couples the SM-like Higgs doublet exclusively to the third quark generation, while the first two generations couple exclusively to an additional source of electroweak symmetry breaking, potentially generating striking collider signatures. We synthesize the flavorful 2HDM with the ‘flavor-locking’ mechanism, that dynamically generates large quark mass hierarchies through a flavor-blind portal to distinct flavon and hierarchon sectors: dynamical alignment of the flavons allows a unique hierarchon to control the respective quark masses. We further develop the theoretical construction of this mechanism, and show that in the context of a flavorful 2HDM-type setup, it can automatically achieve realistic flavor structures: the CKM matrix is automatically hierarchical with |Vcb| and |Vub| generically of the observed size. Exotic contributions to meson oscillation observables may also be generated, that may accommodate current data mildly better than the SM itself.


Beyond Standard Model Higgs Physics Quark Masses and SM Parameters 


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.


  1. [1]
    ATLAS, 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].
  2. [2]
    ATLAS collaboration, Evidence for the \( H\to b\overline{b} \) decay with the ATLAS detector, JHEP 12 (2017) 024 [arXiv:1708.03299] [INSPIRE].
  3. [3]
    CMS collaboration, Evidence for the Higgs boson decay to a bottom quark-antiquark pair, arXiv:1709.07497 [INSPIRE].
  4. [4]
    CMS collaboration, CMS Collaboration, CMS-PAS-HIG-17-019 (2017).
  5. [5]
    ATLAS collaboration, Search for the dimuon decay of the Higgs boson in pp collisions at \( \sqrt{s}=13 \) TeV with the ATLAS detector, Phys. Rev. Lett. 119 (2017) 051802 [arXiv:1705.04582] [INSPIRE].
  6. [6]
    CMS collaboration, Projected Performance of an Upgraded CMS Detector at the LHC and HL-LHC: Contribution to the Snowmass Process, 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 [arXiv:1307.7135] [INSPIRE].
  7. [7]
    ATLAS collaboration, Projections for measurements of Higgs boson cross sections, branching ratios and coupling parameters with the ATLAS detector at a HL-LHC, ATL-PHYS-PUB-2013-014 (2013).
  8. [8]
    M. Testa, Prospects on Higgs Physics at the HL-LHC for ATLAS, talk at Workshop on the physics of HL-LHC, and perspectives at HE-LHC, CERN, 30 October–1 November 2017.Google Scholar
  9. [9]
    ATLAS collaboration, Search for the decay of the Higgs boson to charm quarks with the ATLAS experiment, ATLAS-CONF-2017-078 (2017).
  10. [10]
    LHCb collaboration, Search for \( {H}^0\to b\overline{b} \) or \( c\overline{c} \) in association with a W or Z boson in the forward region of pp collisions, LHCb-CONF-2016-006 (2016).
  11. [11]
    K. Fujii et al., Physics Case for the 250 GeV Stage of the International Linear Collider, arXiv:1710.07621 [INSPIRE].
  12. [12]
    B. Mellado, The status of the LHeC project and its impact on Higgs Physics, in Proceedings, 59th Annual Conference of the South African Institute of Physics (SAIP2014), Johannesburg, South Africa, July 7–11, 2014, pp. 235–240 (2015) [INSPIRE].
  13. [13]
    G. Perez, Y. Soreq, E. Stamou and K. Tobioka, Prospects for measuring the Higgs boson coupling to light quarks, Phys. Rev. D 93 (2016) 013001 [arXiv:1505.06689] [INSPIRE].
  14. [14]
    W. Altmannshofer, J. Brod and M. Schmaltz, Experimental constraints on the coupling of the Higgs boson to electrons, JHEP 05 (2015) 125 [arXiv:1503.04830] [INSPIRE].ADSCrossRefGoogle Scholar
  15. [15]
    F. Bishara, U. Haisch, P.F. Monni and E. Re, Constraining Light-Quark Yukawa Couplings from Higgs Distributions, Phys. Rev. Lett. 118 (2017) 121801 [arXiv:1606.09253] [INSPIRE].ADSCrossRefGoogle Scholar
  16. [16]
    Y. Soreq, H.X. Zhu and J. Zupan, Light quark Yukawa couplings from Higgs kinematics, JHEP 12 (2016) 045 [arXiv:1606.09621] [INSPIRE].ADSCrossRefGoogle Scholar
  17. [17]
    J. Gao, Probing light-quark Yukawa couplings via hadronic event shapes at lepton colliders, JHEP 01 (2018) 038 [arXiv:1608.01746] [INSPIRE].ADSCrossRefGoogle Scholar
  18. [18]
    G. Bonner and H.E. Logan, Constraining the Higgs couplings to up and down quarks using production kinematics at the CERN Large Hadron Collider, arXiv:1608.04376 [INSPIRE].
  19. [19]
    F. Yu, Phenomenology of Enhanced Light Quark Yukawa Couplings and the W ± h Charge Asymmetry, JHEP 02 (2017) 083 [arXiv:1609.06592] [INSPIRE].ADSCrossRefGoogle Scholar
  20. [20]
    L.M. Carpenter, T. Han, K. Hendricks, Z. Qian and N. Zhou, Higgs Boson Decay to Light Jets at the LHC, Phys. Rev. D 95 (2017) 053003 [arXiv:1611.05463] [INSPIRE].ADSGoogle Scholar
  21. [21]
    D. d’Enterria, Higgs physics at the Future Circular Collider, PoS(ICHEP2016)434 [arXiv:1701.02663] [INSPIRE].
  22. [22]
    J. Cohen, S. Bar-Shalom, G. Eilam and A. Soni, Light-quarks Yukawa and new physics in exclusive high-p T Higgs + jet(b-jet) events, Phys. Rev. D 97 (2018) 055014 [arXiv:1705.09295] [INSPIRE].ADSGoogle Scholar
  23. [23]
    CMS collaboration, Search for lepton flavour violating decays of the Higgs boson to μτ and eτ in proton-proton collisions at \( \sqrt{s}=13 \) TeV, CMS-PAS-HIG-17-001 (2017).
  24. [24]
    ATLAS collaboration, Search for lepton-flavour-violating decays of the Higgs and Z bosons with the ATLAS detector, Eur. Phys. J. C 77 (2017) 70 [arXiv:1604.07730] [INSPIRE].
  25. [25]
    ATLAS collaboration, Search for top quark decays tqH, with Hγγ, in \( \sqrt{s}=13 \) TeV pp collisions using the ATLAS detector, JHEP 10 (2017) 129 [arXiv:1707.01404] [INSPIRE].
  26. [26]
    CMS collaboration, Search for the flavor-changing interactions of the top quark with the Higgs boson in \( H\to b\overline{b} \) channel at \( \sqrt{s}=13 \) TeV, CMS-PAS-TOP-17-003 (2017).
  27. [27]
    W. Altmannshofer, S. Gori, A.L. Kagan, L. Silvestrini and J. Zupan, Uncovering Mass Generation Through Higgs Flavor Violation, Phys. Rev. D 93 (2016) 031301 [arXiv:1507.07927] [INSPIRE].ADSGoogle Scholar
  28. [28]
    A.K. Das and C. Kao, A Two Higgs doublet model for the top quark, Phys. Lett. B 372 (1996) 106 [hep-ph/9511329] [INSPIRE].
  29. [29]
    A.E. Blechman, A.A. Petrov and G. Yeghiyan, The Flavor puzzle in multi-Higgs models, JHEP 11 (2010) 075 [arXiv:1009.1612] [INSPIRE].ADSCrossRefzbMATHGoogle Scholar
  30. [30]
    D. Ghosh, R.S. Gupta and G. Perez, Is the Higgs Mechanism of Fermion Mass Generation a Fact? A Yukawa-less First-Two-Generation Model, Phys. Lett. B 755 (2016) 504 [arXiv:1508.01501] [INSPIRE].ADSCrossRefGoogle Scholar
  31. [31]
    F.J. Botella, G.C. Branco, M.N. Rebelo and J.I. Silva-Marcos, What if the masses of the first two quark families are not generated by the standard model Higgs boson?, Phys. Rev. D 94 (2016) 115031 [arXiv:1602.08011] [INSPIRE].ADSGoogle Scholar
  32. [32]
    W. Altmannshofer, J. Eby, S. Gori, M. Lotito, M. Martone and D. Tuckler, Collider Signatures of Flavorful Higgs Bosons, Phys. Rev. D 94 (2016) 115032 [arXiv:1610.02398] [INSPIRE].ADSGoogle Scholar
  33. [33]
    S. Knapen and D.J. Robinson, Disentangling Mass and Mixing Hierarchies, Phys. Rev. Lett. 115 (2015) 161803 [arXiv:1507.00009] [INSPIRE].ADSCrossRefGoogle Scholar
  34. [34]
    N. Cabibbo and L. Maiani, Weak interactions and the breaking of hadron symmetries, in Evolution of particle physics: A volume dedicated to Edoardo Amaldi in his sixtieth birthday, M. Conversi, ed., pp. 50–80 (1970) [INSPIRE].
  35. [35]
    L. Michel and L.A. Radicati, Properties of the breaking of hadronic internal symmetry, Annals Phys. 66 (1971) 758 [INSPIRE].ADSMathSciNetCrossRefGoogle Scholar
  36. [36]
    R. Alonso, M.B. Gavela, L. Merlo and S. Rigolin, On the scalar potential of minimal flavour violation, JHEP 07 (2011) 012 [arXiv:1103.2915] [INSPIRE].ADSCrossRefzbMATHGoogle Scholar
  37. [37]
    R. Alonso, M.B. Gavela, G. Isidori and L. Maiani, Neutrino Mixing and Masses from a Minimum Principle, JHEP 11 (2013) 187 [arXiv:1306.5927] [INSPIRE].ADSCrossRefGoogle Scholar
  38. [38]
    R. Alonso, M.B. Gavela, D. Hernández, L. Merlo and S. Rigolin, Leptonic Dynamical Yukawa Couplings, JHEP 08 (2013) 069 [arXiv:1306.5922] [INSPIRE].ADSCrossRefGoogle Scholar
  39. [39]
    A. Crivellin, J. Fuentes-Martin, A. Greljo and G. Isidori, Lepton Flavor Non-Universality in B decays from Dynamical Yukawas, Phys. Lett. B 766 (2017) 77 [arXiv:1611.02703] [INSPIRE].ADSCrossRefGoogle Scholar
  40. [40]
    S.L. Glashow and S. Weinberg, Natural Conservation Laws for Neutral Currents, Phys. Rev. D 15 (1977) 1958 [INSPIRE].ADSGoogle Scholar
  41. [41]
    A. Pich and P. Tuzon, Yukawa Alignment in the Two-Higgs-Doublet Model, Phys. Rev. D 80 (2009) 091702 [arXiv:0908.1554] [INSPIRE].ADSGoogle Scholar
  42. [42]
    W. Altmannshofer, S. Gori and G.D. Kribs, A Minimal Flavor Violating 2HDM at the LHC, Phys. Rev. D 86 (2012) 115009 [arXiv:1210.2465] [INSPIRE].ADSGoogle Scholar
  43. [43]
    S. Gori, H.E. Haber and E. Santos, High scale flavor alignment in two-Higgs doublet models and its phenomenology, JHEP 06 (2017) 110 [arXiv:1703.05873] [INSPIRE].ADSCrossRefzbMATHGoogle Scholar
  44. [44]
    G. D’Ambrosio, G.F. Giudice, G. Isidori and A. Strumia, Minimal flavor violation: An Effective field theory approach, Nucl. Phys. B 645 (2002) 155 [hep-ph/0207036] [INSPIRE].
  45. [45]
    Particle Data Group collaboration, C. Patrignani et al., Review of Particle Physics, Chin. Phys. C 40 (2016) 100001 [INSPIRE].
  46. [46]
    A. Hocker, H. Lacker, S. Laplace and F. Le Diberder, A New approach to a global fit of the CKM matrix, Eur. Phys. J. C 21 (2001) 225 [hep-ph/0104062] [INSPIRE].
  47. [47]
    CKMfitter Group collaboration, J. Charles et al., CP violation and the CKM matrix: Assessing the impact of the asymmetric B factories, Eur. Phys. J. C 41 (2005) 1 [hep-ph/0406184] [INSPIRE].
  48. [48]
    R.J. Dowdall, C.T.H. Davies, G.P. Lepage and C. McNeile, Vus from pi and K decay constants in full lattice QCD with physical u, d, s and c quarks, Phys. Rev. D 88 (2013) 074504 [arXiv:1303.1670] [INSPIRE].ADSGoogle Scholar
  49. [49]
    ETM collaboration, N. Carrasco et al., ΔS = 2 and ΔC = 2 bag parameters in the standard model and beyond from N f = 2 + 1 + 1 twisted-mass lattice QCD, Phys. Rev. D 92 (2015) 034516 [arXiv:1505.06639] [INSPIRE].
  50. [50]
    SWME collaboration, B.J. Choi et al., Kaon BSM B-parameters using improved staggered fermions from N f = 2 + 1 unquenched QCD, Phys. Rev. D 93 (2016) 014511 [arXiv:1509.00592] [INSPIRE].
  51. [51]
    RBC/UKQCD collaboration, N. Garron, R.J. Hudspith and A.T. Lytle, Neutral Kaon Mixing Beyond the Standard Model with n f = 2 + 1 Chiral Fermions Part 1: Bare Matrix Elements and Physical Results, JHEP 11 (2016) 001 [arXiv:1609.03334] [INSPIRE].
  52. [52]
    A.J. Buras, D. Guadagnoli and G. Isidori, On ϵ K Beyond Lowest Order in the Operator Product Expansion, Phys. Lett. B 688 (2010) 309 [arXiv:1002.3612] [INSPIRE].ADSCrossRefGoogle Scholar
  53. [53]
    J. Brod and M. Gorbahn, Next-to-Next-to-Leading-Order Charm-Quark Contribution to the CP-violation Parameter ϵ K and ΔM K, Phys. Rev. Lett. 108 (2012) 121801 [arXiv:1108.2036] [INSPIRE].ADSCrossRefGoogle Scholar
  54. [54]
    HFLAV collaboration, Y. Amhis et al., 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].
  55. [55]
    Fermilab Lattice, MILC collaborations, A. Bazavov et al., B ( s)0 -mixing matrix elements from lattice QCD for the Standard Model and beyond, Phys. Rev. D 93 (2016) 113016 [arXiv:1602.03560] [INSPIRE].
  56. [56]
    ETM collaboration, N. Carrasco et al., B-physics from N f = 2 tmQCD: the Standard Model and beyond, JHEP 03 (2014) 016 [arXiv:1308.1851] [INSPIRE].
  57. [57]
    M. Blanke and A.J. Buras, Universal Unitarity Triangle 2016 and the tension between ΔM s,d and ε K in CMFV models, Eur. Phys. J. C 76 (2016) 197 [arXiv:1602.04020] [INSPIRE].ADSCrossRefGoogle Scholar
  58. [58]
    A.J. Buras and F. De Fazio, 331 Models Facing the Tensions in ΔF = 2 Processes with the Impact on ε/ε, B sμ + μ and BK * μ + μ , JHEP 08 (2016) 115 [arXiv:1604.02344] [INSPIRE].ADSCrossRefGoogle Scholar

Copyright information

© The Author(s) 2018

Authors and Affiliations

  • Wolfgang Altmannshofer
    • 1
  • Stefania Gori
    • 1
  • Dean J. Robinson
    • 1
    Email author
  • Douglas Tuckler
    • 1
  1. 1.Department of PhysicsUniversity of CincinnatiCincinnatiU.S.A.

Personalised recommendations