1. Matthew Brown, University of Southampton m.s.brown@soton.ac.uk ITEP Winter School, 14 th February 2013

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

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

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

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

6. Higgs decay 6 https://twiki.cern.ch/twiki/bin/view/LHCPhysics/CrossSections ChannelBranching bb58 % WW22 % gg8.6 6.3 % cc2.91 % ZZ2.6 % 0.22 % (h → WW → 22ν)

7. Higgs to two photons 7 -74/3 -7 : 3(2/3) 2 (4/3) -3.9 : 1 SM-like particles don’t decouple as m → ∞ Particles which get mass from elsewhere do decouple (amplitude level)

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

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

10. Excluding BSM models 10

11. Minimal Universal Extra Dimensions 1 extra dimension on S 1 /Z 2 orbifold (chiral interactions) Action 5D Lorentz invariant at cutoff scale KK photon is natural DM candidate KK partners of SM vectors and fermions contribute to loops gg → h enhanced; h → suppressed R -1 is only new parameter 11 Bélanger, Belyaev, Brown, Kakizaki, Pukhov [arxiv:1209.0753]

12. Minimal Universal Extra Dimensions 12

13. Minimal Universal Extra Dimensions 13

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

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

16. 4D Composite Higgs Model 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 16 Barducci, Belyaev, Brown, De Curtis, Moretti, Pruna, in perparation

17. Constraining 4DCHM 17

18. Constraining 4DCHM 18

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, Mads Fandsen, Roshan Foadi, Tuomas Hapola) – E 6 SSM (Belyaev, Svantesson, Pruna) 19

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 20

21. BACKUP SLIDES 21

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 22 Kauer and Passarino, arXiv:1110.1613 Kauer, arXiv:1201.1667

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

24. 4D Composite Higgs Model 24 W Z

25. CL s beginning of backup slides 25

26. Minimal Universal Extra Dimensions 26