Journal of High Energy Physics

, 2015:185 | Cite as

New opportunities in h → 4

Open Access
Regular Article - Theoretical Physics

Abstract

The Higgs decay h → 4 has played an important role in discovering the Higgs and measuring its mass thanks to low background and excellent resolution. Current cuts in this channel have been optimized for Higgs discovery via the dominant tree level ZZ contribution arising from electroweak symmetry breaking. Going forward, one of the primary objectives of this sensitive channel will be to probe other Higgs couplings and search for new physics on top of the tree level ZZ ‘background’. Thanks to interference between these small couplings and the large tree level contribution to ZZ, the h → 4ℓ decay is uniquely capable of probing the magnitude and CP phases of the Higgs couplings to γγ and as well as, to a lesser extent, ZZ couplings arising from higher dimensional operators. With this in mind we examine how much relaxing current cuts can enhance the sensitivity while also accounting for the dominant non-Higgs continuum \( q\overline{q}\to 4\ell \) background. We find the largest enhancement in sensitivity for the hZγ couplings (≳100%) followed by hγγ (≳40%) and less so for the higher dimensional hZZ couplings (a few percent). With these enhancements, we show that couplings of order Standard Model values for hγγ may optimistically be probed by end of Run-II at the LHC while for hZγ perhaps towards the end of a high luminosity LHC. Thus an appropriately optimized h → 4 analysis can complement direct decays of the Higgs to on-shell γγ and pairs giving a unique opportunity to directly access the CP properties of these couplings.

Keywords

Higgs Physics Beyond Standard Model CP violation 

Notes

Open Access

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References

  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]
    A. Falkowski, F. Riva and A. Urbano, Higgs at last, JHEP 11 (2013) 111 [arXiv:1303.1812] [INSPIRE].ADSCrossRefGoogle Scholar
  4. [4]
    CMS collaboration, Constraints on anomalous HVV interactions using H → 4ℓ decays, CMS-PAS-HIG-14-014 (2014).
  5. [5]
    CMS collaboration, Constraints on the spin-parity and anomalous HVV couplings of the Higgs boson in proton collisions at 7 and 8 TeV, Phys. Rev. D 92 (2015) 012004 [arXiv:1411.3441] [INSPIRE].
  6. [6]
    C.A. Nelson, Correlation between decay planes in Higgs-boson decays into a W pair (into a Z pair), Phys. Rev. D 37 (1988) 1220 [INSPIRE].ADSGoogle Scholar
  7. [7]
    A. Soni and R.M. Xu, Probing CP-violation via Higgs decays to four leptons, Phys. Rev. D 48 (1993) 5259 [hep-ph/9301225] [INSPIRE].ADSGoogle Scholar
  8. [8]
    D. Chang, W.-Y. Keung and I. Phillips, CP odd correlation in the decay of neutral Higgs boson into ZZ, W + W , or \( t\overline{t} \), Phys. Rev. D 48 (1993) 3225 [hep-ph/9303226] [INSPIRE].ADSGoogle Scholar
  9. [9]
    V.D. Barger, K.-m. Cheung, A. Djouadi, B.A. Kniehl and P.M. Zerwas, Higgs bosons: intermediate mass range at e + e colliders, Phys. Rev. D 49 (1994) 79 [hep-ph/9306270] [INSPIRE].
  10. [10]
    T. Arens and L.M. Sehgal, Energy spectra and energy correlations in the decay HZZμ + μ μ + μ , Z. Phys. C 66 (1995) 89 [hep-ph/9409396] [INSPIRE].ADSGoogle Scholar
  11. [11]
    S.Y. Choi, D.J. Miller, M.M. Mühlleitner and P.M. Zerwas, Identifying the Higgs spin and parity in decays to Z pairs, Phys. Lett. B 553 (2003) 61 [hep-ph/0210077] [INSPIRE].ADSCrossRefGoogle Scholar
  12. [12]
    C.P. Buszello, I. Fleck, P. Marquard and J.J. van der Bij, Prospective analysis of spin- and CP-sensitive variables in H → ZZ → l 1+ l 1 l 2+ l 2 at the LHC, Eur. Phys. J. C 32 (2004) 209 [hep-ph/0212396] [INSPIRE].ADSCrossRefGoogle Scholar
  13. [13]
    R.M. Godbole, D.J. Miller and M.M. Mühlleitner, Aspects of CP-violation in the HZZ coupling at the LHC, JHEP 12 (2007) 031 [arXiv:0708.0458] [INSPIRE].ADSCrossRefGoogle Scholar
  14. [14]
    V.A. Kovalchuk, Model-independent analysis of CP-violation effects in decays of the Higgs boson into a pair of the W and Z bosons, J. Exp. Theor. Phys. 107 (2008) 774 [INSPIRE].ADSCrossRefGoogle Scholar
  15. [15]
    Q.-H. Cao, C.B. Jackson, W.-Y. Keung, I. Low and J. Shu, The Higgs mechanism and loop-induced decays of a scalar into two Z bosons, Phys. Rev. D 81 (2010) 015010 [arXiv:0911.3398] [INSPIRE].ADSGoogle Scholar
  16. [16]
    Y. Gao et al., Spin determination of single-produced resonances at hadron colliders, Phys. Rev. D 81 (2010) 075022 [arXiv:1001.3396] [INSPIRE].ADSGoogle Scholar
  17. [17]
    A. De Rujula, J. Lykken, M. Pierini, C. Rogan and M. Spiropulu, Higgs look-alikes at the LHC, Phys. Rev. D 82 (2010) 013003 [arXiv:1001.5300] [INSPIRE].ADSGoogle Scholar
  18. [18]
    J.S. Gainer, K. Kumar, I. Low and R. Vega-Morales, Improving the sensitivity of Higgs boson searches in the golden channel, JHEP 11 (2011) 027 [arXiv:1108.2274] [INSPIRE].ADSCrossRefGoogle Scholar
  19. [19]
    B. Coleppa, K. Kumar and H.E. Logan, Can the 126 GeV boson be a pseudoscalar?, Phys. Rev. D 86 (2012) 075022 [arXiv:1208.2692] [INSPIRE].ADSGoogle Scholar
  20. [20]
    S. Bolognesi et al., On the spin and parity of a single-produced resonance at the LHC, Phys. Rev. D 86 (2012) 095031 [arXiv:1208.4018] [INSPIRE].ADSGoogle Scholar
  21. [21]
    D. Stolarski and R. Vega-Morales, Directly measuring the tensor structure of the scalar coupling to gauge bosons, Phys. Rev. D 86 (2012) 117504 [arXiv:1208.4840] [INSPIRE].ADSGoogle Scholar
  22. [22]
    R. Boughezal, T.J. LeCompte and F. Petriello, Single-variable asymmetries for measuring theHiggsboson spin and CP properties, arXiv:1208.4311 [INSPIRE].
  23. [23]
    A. Belyaev, N.D. Christensen and A. Pukhov, CalcHEP 3.4 for collider physics within and beyond the standard model, Comput. Phys. Commun. 184 (2013) 1729 [arXiv:1207.6082] [INSPIRE].ADSCrossRefMATHGoogle Scholar
  24. [24]
    P. Avery et al., Precision studies of the Higgs boson decay channel HZZ → 4ℓ with MEKD, Phys. Rev. D 87 (2013) 055006 [arXiv:1210.0896] [INSPIRE].ADSGoogle Scholar
  25. [25]
    J.M. Campbell, W.T. Giele and C. Williams, Extending the matrix element method to next-to-leading order, arXiv:1205.3434 [INSPIRE].
  26. [26]
    J.M. Campbell, W.T. Giele and C. Williams, The matrix element method at next-to-leading order, JHEP 11 (2012) 043 [arXiv:1204.4424] [INSPIRE].ADSCrossRefGoogle Scholar
  27. [27]
    Y. Chen, N. Tran and R. Vega-Morales, Scrutinizing the Higgs signal and background in the 2e2μ golden channel, JHEP 01 (2013) 182 [arXiv:1211.1959] [INSPIRE].ADSCrossRefGoogle Scholar
  28. [28]
    B. Grinstein, C.W. Murphy and D. Pirtskhalava, Searching for new physics in the three-body decays of the Higgs-like particle, JHEP 10 (2013) 077 [arXiv:1305.6938] [INSPIRE].ADSCrossRefGoogle Scholar
  29. [29]
    A. Menon, T. Modak, D. Sahoo, R. Sinha and H.-Y. Cheng, Inferring the nature of the boson at 125-126 GeV, Phys. Rev. D 89 (2014) 095021 [arXiv:1301.5404] [INSPIRE].ADSGoogle Scholar
  30. [30]
    Y. Sun, X.-F. Wang and D.-N. Gao, CP mixed property of the Higgs-like particle in the decay channel hZZ * → 4l, Int. J. Mod. Phys. A 29 (2014) 1450086 [arXiv:1309.4171] [INSPIRE].ADSCrossRefGoogle Scholar
  31. [31]
    J.S. Gainer, J. Lykken, K.T. Matchev, S. Mrenna and M. Park, Geolocating the Higgs boson candidate at the LHC, Phys. Rev. Lett. 111 (2013) 041801 [arXiv:1304.4936] [INSPIRE].ADSCrossRefGoogle Scholar
  32. [32]
    I. Anderson et al., Constraining anomalous HVV interactions at proton and lepton colliders, Phys. Rev. D 89 (2014) 035007 [arXiv:1309.4819] [INSPIRE].ADSGoogle Scholar
  33. [33]
    M. Chen et al., The role of interference in unraveling the ZZ-couplings of the newly discovered boson at the LHC, Phys. Rev. D 89 (2014) 034002 [arXiv:1310.1397] [INSPIRE].ADSGoogle Scholar
  34. [34]
    G. Buchalla, O. Catà and G. D’Ambrosio, Nonstandard Higgs couplings from angular distributions in hZℓ + , Eur. Phys. J. C 74 (2014) 2798 [arXiv:1310.2574] [INSPIRE].ADSCrossRefGoogle Scholar
  35. [35]
    Y. Chen and R. Vega-Morales, Extracting effective Higgs couplings in the golden channel, JHEP 04 (2014) 057 [arXiv:1310.2893] [INSPIRE].ADSCrossRefGoogle Scholar
  36. [36]
    Y. Chen et al., 8D likelihood effective Higgs couplings extraction framework in h → 4, JHEP 01 (2015) 125 [arXiv:1401.2077] [INSPIRE].ADSCrossRefGoogle Scholar
  37. [37]
    J.S. Gainer, J. Lykken, K.T. Matchev, S. Mrenna and M. Park, Beyond geolocating: constraining higher dimensional operators in H → 4ℓ with off-shell production and more, Phys. Rev. D 91 (2015) 035011 [arXiv:1403.4951] [INSPIRE].ADSGoogle Scholar
  38. [38]
    Y. Chen, R. Harnik and R. Vega-Morales, Probing the Higgs couplings to photons in h → 4ℓ at the LHC, Phys. Rev. Lett. 113 (2014) 191801 [arXiv:1404.1336] [INSPIRE].ADSCrossRefGoogle Scholar
  39. [39]
    M. Gonzalez-Alonso, A. Greljo, G. Isidori and D. Marzocca, Pseudo-observables in Higgs decays, Eur. Phys. J. C 75 (2015) 128 [arXiv:1412.6038] [INSPIRE].ADSCrossRefGoogle Scholar
  40. [40]
    W. Murray, HL-LHC Higgs potential, talk given at the ECFA High Luminosity LHC Experiments Workshop, Aix-les-Bains France, 1–3 Oct 2013, http://indico.cern.ch/event/252045/session/3/contribution/8/material/slides/0.pdf.
  41. [41]
    Y. Chen, A. Falkowski, I. Low and R. Vega-Morales, New observables for CP-violation in Higgs decays, Phys. Rev. D 90 (2014) 113006 [arXiv:1405.6723] [INSPIRE].ADSGoogle Scholar
  42. [42]
    F. Bishara et al., Probing CP-violation in hγγ with converted photons, JHEP 04 (2014) 084 [arXiv:1312.2955] [INSPIRE].ADSCrossRefGoogle Scholar
  43. [43]
    B. Grzadkowski, M. Iskrzynski, M. Misiak and J. Rosiek, Dimension-six terms in the standard model Lagrangian, JHEP 10 (2010) 085 [arXiv:1008.4884] [INSPIRE].ADSCrossRefMATHGoogle Scholar
  44. [44]
    M. Dührssen-Debling, A.T. Mendes, A. Falkowski and G. Isidori, Higgs basis: proposal for an EFT basis choice for LHC HXSWG, LHCHXSWG-INT-2015-001 (2015).
  45. [45]
    A. Pomarol and F. Riva, Towards the ultimate SM fit to close in on Higgs physics, JHEP 01 (2014) 151 [arXiv:1308.2803] [INSPIRE].ADSCrossRefGoogle Scholar
  46. [46]
    A. Falkowski and F. Riva, Model-independent precision constraints on dimension-6 operators, JHEP 02 (2015) 039 [arXiv:1411.0669] [INSPIRE].ADSCrossRefGoogle Scholar
  47. [47]
    A. Falkowski, Effective field theory approach to LHC Higgs data, arXiv:1505.00046 [INSPIRE].
  48. [48]
    Y. Chen, A. Falkowski, R. Harnik and R. Vega-Morales, Probing effective Higgs couplings in h → 4, in preparation.Google Scholar
  49. [49]
    M. Gonzalez-Alonso, A. Greljo, G. Isidori and D. Marzocca, Electroweak bounds on Higgs pseudo-observables and h → 4ℓ decays, Eur. Phys. J. C 75 (2015) 341 [arXiv:1504.04018] [INSPIRE].ADSCrossRefGoogle Scholar
  50. [50]
    Y. Chen, D. Stolarski and R. Vega-Morales, Golden probe of the top Yukawa, Phys. Rev. D 92 (2015) 053003 [arXiv:1505.01168] [INSPIRE].ADSGoogle Scholar
  51. [51]
    A. Bredenstein, A. Denner, S. Dittmaier and M.M. Weber, Precise predictions for the Higgs-boson decay HWW/ZZ → 4 leptons, Phys. Rev. D 74 (2006) 013004 [hep-ph/0604011] [INSPIRE].ADSGoogle Scholar
  52. [52]
    A. Bredenstein, A. Denner, S. Dittmaier and M.M. Weber, Precision calculations for the Higgs decays HZZ/WW → 4 leptons, Nucl. Phys. Proc. Suppl. 160 (2006) 131 [hep-ph/0607060] [INSPIRE].ADSCrossRefGoogle Scholar
  53. [53]
    M. Bordone, A. Greljo, G. Isidori, D. Marzocca and A. Pattori, Higgs pseudo observables and radiative corrections, Eur. Phys. J. C 75 (2015) 385 [arXiv:1507.02555] [INSPIRE].ADSCrossRefGoogle Scholar
  54. [54]
    C. Hartmann and M. Trott, On one-loop corrections in the standard model effective field theory; the Γ(hγγ) case, JHEP 07 (2015) 151 [arXiv:1505.02646] [INSPIRE].ADSCrossRefGoogle Scholar
  55. [55]
    M. Ghezzi, R. Gomez-Ambrosio, G. Passarino and S. Uccirati, NLO Higgs effective field theory and κ-framework, JHEP 07 (2015) 175 [arXiv:1505.03706] [INSPIRE].ADSMathSciNetCrossRefGoogle Scholar
  56. [56]
    C. Hartmann and M. Trott, Higgs decay to two photons at one-loop in the SMEFT, arXiv:1507.03568 [INSPIRE].
  57. [57]
    J. Elias-Miro, J.R. Espinosa, E. Masso and A. Pomarol, Higgs windows to new physics through d = 6 operators: constraints and one-loop anomalous dimensions, JHEP 11 (2013) 066 [arXiv:1308.1879] [INSPIRE].ADSCrossRefGoogle Scholar
  58. [58]
    R.S. Gupta, A. Pomarol and F. Riva, BSM primary effects, Phys. Rev. D 91 (2015) 035001 [arXiv:1405.0181] [INSPIRE].ADSGoogle Scholar
  59. [59]
    M. Trott, On the consistent use of constructed observables, JHEP 02 (2015) 046 [arXiv:1409.7605] [INSPIRE].ADSCrossRefGoogle Scholar
  60. [60]
    I. Low, J. Lykken and G. Shaughnessy, Have we observed the Higgs (imposter)?, Phys. Rev. D 86 (2012) 093012 [arXiv:1207.1093] [INSPIRE].ADSGoogle Scholar
  61. [61]
    ATLAS collaboration, Measurements of Higgs boson production and couplings in diboson final states with the ATLAS detector at the LHC, Phys. Lett. B 726 (2013) 88 [Erratum ibid. B 734 (2014) 406] [arXiv:1307.1427] [INSPIRE].
  62. [62]
    D. McKeen, M. Pospelov and A. Ritz, Modified Higgs branching ratios versus CP and lepton flavor violation, Phys. Rev. D 86 (2012) 113004 [arXiv:1208.4597] [INSPIRE].ADSGoogle Scholar
  63. [63]
    ACME collaboration, J. Baron et al., Order of magnitude smaller limit on the electric dipole moment of the electron, Science 343 (2014) 269 [arXiv:1310.7534] [INSPIRE].
  64. [64]
    CMS collaboration, Study of the mass and spin-parity of the Higgs boson candidate via its decays to Z boson pairs, Phys. Rev. Lett. 110 (2013) 081803 [arXiv:1212.6639] [INSPIRE].
  65. [65]
    CMS collaboration, Measurement of the properties of a Higgs boson in the four-lepton final state, Phys. Rev. D 89 (2014) 092007 [arXiv:1312.5353] [INSPIRE].
  66. [66]
    G. Isidori, A.V. Manohar and M. Trott, Probing the nature of the Higgs-like boson via hVF decays, Phys. Lett. B 728 (2014) 131 [arXiv:1305.0663] [INSPIRE].ADSCrossRefGoogle Scholar
  67. [67]
    M. Gonzalez-Alonso and G. Isidori, The h → 4l spectrum at low m 34 : standard model vs. light new physics, Phys. Lett. B 733 (2014) 359 [arXiv:1403.2648] [INSPIRE].ADSCrossRefGoogle Scholar
  68. [68]
    CMS collaboration, Search for a non-standard-model Higgs boson decaying to a pair of new light bosons in four-muon final states, Phys. Lett. B 726 (2013) 564 [arXiv:1210.7619] [INSPIRE].
  69. [69]
    CTEQ collaboration, H.L. Lai et al., Global QCD analysis of parton structure of the nucleon: CTEQ5 parton distributions, Eur. Phys. J. C 12 (2000) 375 [hep-ph/9903282] [INSPIRE].
  70. [70]
    J. Pumplin et al., New generation of parton distributions with uncertainties from global QCD analysis, JHEP 07 (2002) 012 [hep-ph/0201195] [INSPIRE].ADSCrossRefGoogle Scholar
  71. [71]
    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
  72. [72]
    Y. Chen et al., Technical note for 8D likelihood effective Higgs couplings extraction framework in the golden channel, arXiv:1410.4817 [INSPIRE].
  73. [73]
    LHC Higgs Cross Section Working Group collaboration, S. Dittmaier et al., Handbook of LHC Higgs cross sections: 1. Inclusive observables, arXiv:1101.0593 [INSPIRE].
  74. [74]
    LHC Higgs Cross Section Working Group collaboration, J.R. Andersen et al., Handbook of LHC Higgs cross sections: 3. Higgs properties, arXiv:1307.1347 [INSPIRE].

Copyright information

© The Author(s) 2015

Authors and Affiliations

  1. 1.Lauritsen Laboratory for High Energy PhysicsCalifornia Institute of TechnologyPasadenaUnited States
  2. 2.Theoretical Physics DepartmentFermilabBataviaUnited States
  3. 3.Laboratoire de Physique Théorique, CNRS-UMR 8627, Université Paris-Sud 11Orsay CedexFrance

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