Phenomenology Beyond the Standard Model

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STANDARD MODEL
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There must be New Physics Beyond the Standard
Model
viXra Bloggers Combination of Dec.13th Data
Precision Electroweak data?? Higgs coupling blows
up!!
Higgs coupling less than in Standard Model
Higgs potential collapses
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Theorists getting Cold Feet

• Composite Higgs model?
• conflicts with precision electroweak data
• Interpretation of EW data?
• consistency of measurements? Discard some?
• Higgs higher-dimensional operators?
• corridors to higher Higgs masses?
• Little Higgs models?
• extra Top, gauge bosons, Higgses
• Higgsless models?
• strong WW scattering, extra D?

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Heretical Interpretation of EW Data
Do all the data tell the same story? e.g., AL vs
AH
What most of us think
Chanowitz
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Estimates of mH from different Measurements
Spread looks natural no significant disagreement
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Higgs Higher-Order Operators
Corridor to heavy Higgs?
Precision EW data suggest they are small why?
Do not discard possibility of heavy Higgs
Barbieri, Strumia
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(No Transcript)
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Elementary Higgs or Composite?

• Higgs field
• lt0H0gt ? 0
• Quantum loop problems

• Fermion-antifermion condensate
• Just like QCD, BCS superconductivity
• Top-antitop condensate? needed mt gt 200 GeV

Cutoff ? 10 TeV

• New technicolour force?
• Heavy scalar resonance?
• Inconsistent with
• precision electroweak data?

Cut-off ? 1 TeV with Supersymmetry?
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Comparison between Weakly- and Strongly-coupled
Models
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Interpolating Models

• Combination of Higgs boson and vector ?
• Two main parameters m? and coupling g?
• Equivalently ratio weak/strong scale
• g? / m?

Grojean, Giudice, Pomarol, Rattazzi
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Intermediate Models
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Effects on Higgs Decays

• Dependences on ? of Higgs branching ratios
• Standard Model recovered in limit ??0

Grojean, Giudice, Pomarol, Rattazzi
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Higgs as a Pseudo-Goldstone Boson
Little Higgs models (breakdown of larger
symmetry)
Loop cancellation mechanism
Supersymmetry
Little Higgs
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Little Higgs Models

• Embed SM in larger gauge group
• Higgs as pseudo-Goldstone boson
• Cancel top loop
• with new heavy T quark
• New gauge bosons, Higgses
• Higgs light, other new
• physics heavy

MT lt 2 TeV (mh / 200 GeV)2 MW lt 6 TeV (mh / 200
GeV)2 MH lt 10 TeV
Not as complete as susy more physics gt 10 TeV
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Examples of Higgs as Pseudo-Goldstone Boson

• Parameterization of effective Lagrangian
• Examples
• To be measured!

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What if the Higgs is not quite a Higgs?

• Tree-level Higgs couplings masses
• Coefficient 1/v
• Couplings dilaton of scale invariance
• Broken by Higgs mass term µ2, anomalies
• Cannot remove µ2 (Coleman-Weinberg)
• Anomalies give couplings to ??, gg
• Generalize to pseudo-dilaton of new (nearly)
  conformal strongly-interacting sector
• Pseudo-Goldstone boson of scale symmetry

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A Phenomenological Profile of a Pseudo-Dilaton

• Universal suppression of couplings to Standard
  Model particles a c v/V
• Effective potential
• Self-couplings
• G(gg) may be enhanced
• G(??) may be suppressed

Compilation of constraints
Updated with Dec. 11 constraints
Pseudo-baryons as dark matter?
Campbell, JE, Olive arXiv1111.4495
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General Analysis of Less Higgs Models

• Parameterization of effective Lagrangian
• Fits

a ? c
Azatov, Contino, Galloway arXiv1202.3415
Espinosa, Grojean, Muhlleitner, Trott
arXiv1202.3697
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General Analysis of Less Higgs Models

• Separate fits to CMS and ATLAS data

Azatov, Contino, Galloway arXiv1202.3415
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Sum Rule for More or Less Higgs Models

• What if Higgs-V-V couplings differ from SM?
• Unitarity imposes sum rule on scattering in
  different isospin channels
• If Higgs coupling gt Standard Model (a2 gt 1), must
  have non-zero scattering with I 2

Fialkowski, Rychkov, Urban arXiv1202.1532
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Higgsless Models?

• Four-dimensional versions
• Strong WW scattering _at_ TeV, incompatible with
  precision data?
• Break EW symmetry by boundary conditions in extra
  dimension
• delay strong WW scattering to 10 TeV?
• Kaluza-Klein modes mKK gt 300 GeV?
• compatibility with precision data?
• Warped extra dimension brane kinetic terms?

Lightest KK mode _at_ few 00 GeV, strong WW _at_ 6-7
TeV
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Particle Spectrum in Simplest Model with Extra
Dimensions

• Lowest-lying states have flat wave functions (n
  0)
• Excitations (Kaluza-Klein) have nodes (n gt 0)
• Mass n/R (R radius of circle)

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Fold Circle Orbifold

• Identify two halves of circle up to a minus sign
• Even particles include massless odd ones all
  massive
• A way to give masses to particles that are
  asymmetric

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Mechanism to break Gauge Symmetry

• Identify two halves up to a group transformation
  U
• Unbroken part of gauge group commutes with U
• Masses for asymmetric particles
• e.g., SU(2) U(1) ? U(1)

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Search for Vector Resonance in Higgsless Model

• Vector resonance structure in WZ scattering

Simulation of resonance structure in mWZ _at_ LHC