Status of the Exploration of the Higgs sector at the LHC (Points for Discussion) Bruce Mellado University of the Witwatersrand LHCDM, IACS, Kolkata 24/02/15 1

2 On July 4 th reported bot experiments reported ~5σ effects Habemus novum Boson Phys.Lett. B716 (2012) 1-29 Phys.Lett. B716 (2012) 30-61

Higgs Cross-Sections at LHC 3

Main Decay Modes H , ,bbH  WW (*),ZZ (*) 4

5 Measurement of the Signal Strengths (Standard Model)

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7 Overall, data seems to be indicative of consistence with SM Higgs hypothesis

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9 Scale factor of fermionic Yukawa coupling Scale factor of coupling to Weak Bosons ATLAS-CONF

10 Observation of the VBF production mechanism at the LHC The observation of the VBF production mechanism with the so-called VBF- topology is an important milestone for the demonstration of the SM-like nature of the coupling of the newly discovered scalar to EW bosons.

11 The VBF Signal at the LHC

12 The VBF Signal at the LHC

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14 Spin/CP Exploration

15 In the standard model there is a physical state, a Higgs boson with well defined couplings to weak bosons, fermions and self interactions The exploration of the coupling to weak bosons plays now a pivotal role in understanding the nature of the scalar boson observed experimentally. New physics can be hidden in these couplings.

16 Spin/CP Exploration: Decay

17 Spin/CP in H->ZZ->4l Exploit full 4- lepton kinematics, combined into a multivariate analysis (BDT) Most sensitive channel in decay to 0 - Phys.Lett. B726 (2013)

18 Data show compatibility with the SM 0 + hypothesis while other alternative hypotheses considered are excluded at a confidence levels above 95% Observation Phys.Lett. B726 (2013)

19 CMS-PAS-HIG CP-violating CP-conserving Λ - Scale of new physics

20 Spin-1 Spin-2

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23 Interference-related probabilities used in the Spin-0 study Probabilities build with LO ME from MCFM, MadGraph and FeynRules

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25 Exclusion of Spin-1 hypotheses

26 Exclusion of Spin-2 hypotheses

27 Spin/CP Exploration: Production

SM Higgs via VBF Qualitative remarks  Unlike QCD partons that scale like 1/P T 2, here P T ~sqrt(1- x)M W 28  Due to the 1/x behavior of the Weak boson the outgoing parton energy (1-x)E is large  forward jets  At high P T

29 Higgs Decay Products Scattered fermions Central Jet Veto   Well-defined prediction of the SM. Kinematics of scattered quarks, very sensitive to new physics

30 T.Plehn, D.Rainwater and D.Zeppenfeld Phys.Rev.Lett. 88 (2002)

31 C. Englert, D. Gonsalves-Neto, K.Mawatari and T. Plehn, JHEP 1301 (2013) 148 A. Djouadi, R.M. Godbole, B.M., K.Mohan, Phys. Lett. B SM Extension of the SM high higher dimension operators. Where the Lambdas are effective coupling strengths. CP-conserving CP-violating General tensor form of HVV coupling, where H is a scalar

32 In the above mention papers we realized that the kinematics of the scattered quarks have more information about the tensor structure of the HVV coupling than hitherto believed Problem with unitarization

33 Spin-2

34 Associated VH production [ Z(  ll)H(  bb) ]

35 Associated VH production

36 Differential Cross-sections

37 Differential Cross-section Measurements

38 Differential Cross-section Results Eagerly awaiting for CMS results. Expecting paper soon

39 Yield and differential cross-sections with the 4l decay yield similar results Yield distributions Unfolded fiducial cross- sections

40 Weighted yield distribution

41 Search for Invisible Decays

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45 Other Searches Many BSM searches are not reviewed here. For more info please check

46 The Big Five in a 2HDM is a focus in current searches. So far no significant excesses found. Stay tuned for Run II. G. Hamity

47 G. Hamity 2HDM

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49 Search for hh resonance with the γγbb decay combination yields weaker- than-expected limits for masses below 350 GeV. Not significant excess when taken into account look- elsewhere effect. Worth looking into this with Run II data Diphoton invariant mass spectrum requiring at least two b-tags Constrained invariant mass

50 No significant excess in γγbb

51 The Future of the LHC

The LHC roadmap to fully exploit the physics potential

Overview and Conclusions  The discovery of a scalar boson with M H around 125 GeV is now well established.  Analysis of the Run I data: 1.Coupling strength compatible with SM Available data on h is used to extract limits on extended Higgs sector (2HDM) 2.Evidence for VBF production 3.Spin/CP studies compatible with 0 + hypothesis 4.No significance excess in searches for new bosons seen so far 5.No evidence of DM in connection with the Higgs sector reported so far  New data taking period to start soon. Stay tuned for Run II 53