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Is it a (Beyond the) Standard Model Higgs?

Based on: “Global Analysis of the Higgs Candidate with Mass ~125 GeV”, John Ellis and T. Y., arXiv:1207.1693 [hep-ph].

See also our previous paper: John Ellis and T. Y., JHEP 1206 (2012) 140, [arXiv:1204.0464 [hep-ph]].

Contents

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  Introduction  Naturalness  Phenomenological Framework  Re-interpreting SM Higgs Searches  Global Experimental Constraints  Other Higgs Properties  Conclusion

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Introduction

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Introduction

4 Image Credit: J. Olsson, STFC, NY Times, AP

CERN July 4th 2012

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Introduction

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Introduction

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Introduction

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•  Technicolor

•  Fundamental Scalar (SM Higgs)

•  Higgs + SUSY

•  Composite Higgs

•  NMSSM

Simplicity Naturalness

•  Little Higgs

•  Composite 2HDM

•  Walking Technicolor

•  Extra Dimensions

•  2HDM

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Naturalness

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Naturalness

  Galileo (1589), Newton (1687):   minertial = mgravity

  Equivalence principle General Relativity

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  Susskind (1979), ‘t Hooft (1980):   (mh)2

tree + (mh)2radiative = (mh)2

v

  Hierarchy problem ?

  Not regularization-dependent:

  A fundamental scalar is quadratically sensitive to high energies

  EM analogy, electron rest energy contribution from Coulomb field:

  Avoid fine-tuning: Predicts new physics at ~10^-15m!

  Parametrize possible new physics at TeV scale? Start with what we know below TeV scale…

Naturalness

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Phenomenological Framework

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Phenomenological Framework

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Phenomenological Framework

13 See previous paper: John Ellis and T. Y., JHEP 1206 (2012) 140, [arXiv:1204.0464 [hep-ph]]. 8/22/12 Tevong You

Phenomenological Framework

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  a parametrizes couplings of h to massive gauge bosons

  c parametrizes couplings of h to fermions

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•  Standard Model:

•  Composite Higgs MCHM4:

•  Composite Higgs MCHM5:

•  Pseudo-Dilaton:

Phenomenological Framework

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Your Favourite Model x

Re-interpreting SM Higgs Searches

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Re-interpreting SM Higgs Searches

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https://indico.cern.ch/getFile.py/access?contribId=0&resId=0&materialId=slides&confId=197461

  Example

Re-interpreting SM Higgs Searches

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  Extract Likelihood using expected and observed 95% CL limit on mu

  Assume Gaussian limit of Poisson-distributed Likelihood*:

  If best fit mu provided, use that instead assuming Gaussian error bars

*See A. Azatov, R. Contino and J. Galloway, arXiv:1202.3415.

Re-interpreting SM Higgs Searches

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  Likelihood where

Re-interpreting SM Higgs Searches

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Re-interpreting SM Higgs Searches

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  Experimental search (sub)channels:

Global Experimental Constraints

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Global Experimental Constraints

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  Couplings proportional to masses?   Assumed SM couplings:

  Generalize scale and power couplings:

  Corresponding to rescaling factors

Global Experimental Constraints

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  Fit for our anomalous scaling model:

Global Experimental Constraints

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  Fit for our anomalous scaling model:

Global Experimental Constraints

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Your Favourite Model x

Global Experimental Constraints

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  CMS

Global Experimental Constraints

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  CMS

Global Experimental Constraints

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  CMS

Global Experimental Constraints

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  CMS

Global Experimental Constraints

8/22/12 31 For -|c| discussion see M. Reece, arxiv:1208.1765

Global Experimental Constraints

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  CMS

Global Experimental Constraints

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  ATLAS

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Global Experimental Constraints

Global Experimental Constraints

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  Tevatron

Global Experimental Constraints

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Other Higgs Properties

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Other Higgs Properties

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  Spin determination, 0 or 2?   Many studies on ‘golden’ ZZ channel   WW and diphoton channel also worth considering

  Best discrimination may come from combination!

See e.g. S.Y. Choi et al (0210077), E. De Sanctis et al (1103.1973), Y. Gao et al (1001.3396), J.S. Gainer et al (1108.2274)

J. Ellis and D.S. Hwang (1202.6660)

J. Ellis, R. Fok, D.S. Hwang, V. Sanz and T.Y (in progress)

Just appeared: S. Bolognesi et al (1208.4018)

Conclusion

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Conclusion

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  Discovery of a new boson of fundamental significance (it’s real!)

  Consistent with SM Higgs couplings to fermions/gauge bosons with expected power law and scale

  Spin yet to be determined   Picture is still blurry, BSM physics could lie

beneath statistical fluctuations   Hopeful that closing the door on SM chapter will

open up a new one… Wait and see!

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“Theorists used to have difficulty believing anything that wasn’t experimentally proven. Now they believe anything that isn’t experimentally disproven.”

-Unknown

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Thank You