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BSM p hysics: what can the Higgs tell us?

BSM p hysics: what can the Higgs tell us?. Matthew Brown, University of Southampton m.s.brown@soton.ac.uk ITEP Winter School, 14 th February 2013. Outline. Framework for SM Higgs Testing BSM theories Results for MUED Bélanger , Belyaev , Kakizaki , Pukhov [1209.0753 ]

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BSM p hysics: what can the Higgs tell us?

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  1. BSM physics: what can the Higgs tell us? Matthew Brown, University of Southampton m.s.brown@soton.ac.uk ITEP Winter School, 14th February 2013

  2. Outline • Framework for SM Higgs • Testing BSM theories • Results for • MUED Bélanger, Belyaev, Kakizaki, Pukhov[1209.0753] • 4DCHMBelyaev, Barducci, de Curtis, Moretti, Pruna[on arXiv!] • Conclusions and outlook

  3. Higgs production Gluon-gluon fusion 87% Higgs Strahlung 4.8% √s = 8 TeV Mh= 125 GeV Vector boson fusion (VBF) 7% Associate top production 0.58%

  4. Higgs production https://twiki.cern.ch/twiki/bin/view/LHCPhysics/CrossSections

  5. Higgs production https://twiki.cern.ch/twiki/bin/view/LHCPhysics/CrossSections

  6. Higgs decay h → 𝛾𝛾 h → ZZ → 4𝓁 (h → WW → 2𝓁2ν) https://twiki.cern.ch/twiki/bin/view/LHCPhysics/CrossSections

  7. Higgs to two photons 𝛾 𝛾 𝛾 𝛾 𝛾 𝛾 -7 4/3 • SM-like particles don’t decouple as m → ∞ • Particles which get mass from elsewhere do decouple -7 : 3⨉(2/3)2 ⨉ (4/3) -3.9 : 1 (amplitude level)

  8. Characterising the excess CMS-HIG-12-045, conference note, Nov 2012

  9. Calculating μ • If one production process dominates… • If several production processes are significant we mustbe told efficiencies!

  10. Excluding BSM models

  11. Minimal Universal Extra Dimensions Bélanger, Belyaev, Brown, Kakizaki, Pukhov [arxiv:1209.0753] • 1 extra dimension on S1/Z2orbifold (chiral interactions) • Action 5D Lorentz invariantat cutoff scale • KK photon is natural DM candidate • KK partners of SM vectors and fermions contribute to loops • gg → h enhanced; h → 𝛾𝛾 suppressed • R-1 is only new parameter

  12. Minimal Universal Extra Dimensions 𝛾 𝛾 𝛾 𝛾 𝛾 𝛾 𝛾 𝛾 𝛾 𝛾

  13. Minimal Universal Extra Dimensions

  14. Constraining MUED 95% CL limits on parameter space Theoretical uncertainties due to radiative mass corrections Bélanger, Belyaev, Brown, Kakizaki, Pukhov [arxiv:1209.0753]

  15. Constraining MUED Bélanger, Belyaev, Brown, Kakizaki, Pukhov (2013) [arxiv:1209.0753]

  16. 4D Composite Higgs Model Barducci, Belyaev, Brown, De Curtis, Moretti, Pruna, in perparation • New strongly interacting sector possessing global symmetry • Symmetry is spontaneously broken • Four of the (pseudo) Nambu-Goldstone bosons form the SM Higgs doublet • Makes Higgs naturally light • New top- and bottom-like quarks and W’/Z’s. Also exotically charged quarks

  17. Constraining 4DCHM

  18. Constraining 4DCHM

  19. Conclusions • Higgs physics can place powerful constraints on BSM models • Model dependent tests must be performed to properly test plausible models of new physics • I am investigating Higgs physics of • MUED [1209.0753] • 4DCHM [on arXiv] • Technicolor models (Sasha, MadsFandsen, RoshanFoadi, TuomasHapola) • E6SSM (Belyaev, Svantesson, Pruna)

  20. Outlook • Higgs couplings are poorly resolved at present, but will errors decrease with new data • Experimentalists will need to release more information (Likelihoods? Efficiencies?) as precision becomes important

  21. Backup slides

  22. Higgs physics assumptions • Negligible interference with background • Narrow-width approximation • Produce on-shell Higgs (PDFs become simple factors) • Multiply by decay branching ratio (BR) to find complete pp → h → XX cross-section • NWA → 1% error. Must go beyond when statistical errors fall Kauer, arXiv:1201.1667 Kauer and Passarino, arXiv:1110.1613

  23. Excluding BSM models • For n ≫ 1… • Multiply likelihoods of different channels and experiments → sum exponents

  24. 4D Composite Higgs Model W Z

  25. CLs beginning of backup slides

  26. Minimal Universal Extra Dimensions 𝛾 𝛾 𝛾 𝛾 𝛾 𝛾 𝛾 𝛾 𝛾 𝛾

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