Transcript From Supersymmetry to QCD and Beyond

The Niels Bohr Institute
Dynamical Electroweak Breaking @ LHC
Francesco Sannino
MC-Workshop
Frascati - 2006
Low Energy Effective Theory
SM
….is not so standard
• Origin of Mass of weak gauge bosons, quarks and leptons is
unknown.
• Strong Interactions are not fully understood/explored.
• Unnaturally small Neutron Electric Dipole Moment
Strong CP problem:
New Challenges from Cosmology.
• Dark Energy/Matter
Focus on two..and
aspects
of the SM
Beyond
New
as
Origin of Mass for the weak gauge bosons, quarks …
Understanding Strong Dynamics
Let there be Mass
Electroweak Precision Measurements
We can already test New Physics!
Kennedy,Lynn, Peskin-Takeuchi, Altarelli-Barbieri, Bertolini-Sirlin,
Marciano-Rosner,..:
Present Data
mH=150 GeV
hep-ex/0509008
Now:
Dutta, Hagiwara and Yan ph/0603038.Weaken constraints
S = 0.07±0.10
The Higgs Mechanism in Nature
Superconductivity
Macroscopic-Screening
Non-Relativistic
SM-Screening
Relativistic
Meissner-Mass
Static Vector Potential
Hidden structure
Weak-GB-Mass
????
Elementary Higgs:
Trivial and Non-natural
Natural Scalars
Exact Super Symmetry:
Fermions ↔ Bosons
Fermion’s custodial symmetry protects the Bosons
Observe: susy partners
Composite Scalar:
Recall Superconductivity
Substructure resolved at scale ΛS
Observe: New Bound States
Quasi Goldstone Boson:
Protected by spontaneously broken global symmetries.
Near Continuous Quantum Phase Transition
Zero-temperature Bose – Einstein Condensation
Lorentz symmetry is broken.
Chiral Phase Transition at zero temperature.
Lorentz symmetry is intact.
Electroweak Symmetry Breaking
@
LHC
Electroweak Symmetry Breaking
Technicolor
SUSY
Extra Dim.
Curved
Flat
Technicolor
New Strong Interactions at ~ 250 GeV
[Weinberg, Susskind]
Natural to use QCD-like dynamics.
Problems with the Old Models
• S-parameter: too large
• Large Flavor Changing Neutral Currents (FCNC)
• Limited knowledge of strong dynamics!
Fermion masses versus FCNC
SM-Fermion
Masses
PNG
Masses
 ETC
FCNC
Operators
should be sufficiently larger than TC  250GeV
to reduce FCNC.
Progress: Appelquist, Christensen, Piai, Shrok
Near Conformal Properties
α
α
non-conformal
near-conformal
ΛETC = 100-1000 ΛTC
ΛTC
ΛTC
q
ΛETC
q
β
Holdom
Appelquist
Miransky, Yamawaki
Cohen and Georgi…
αc
α*
α
Why the walking can help ?
QCD-Like
~
Near the conformal window
~
Critical Number of techniflavors
For fermions in the fundamental representation near conformal
means:
The number of techndoublets is
Still too large S-parameter
The S-parameter for fermions in the fundamental  is
Appelquist - Sannino
Near conformal for N=2 means Nf/2=4 which yields:
Experimentally S = 0.07±0.10
The New Model
Near conformal for, Nf  2
Small FCNC + Top mass
OK with precision data.
Light Composite Higgs
Dark Matter
Sannino-Tuominen, hep-ph/0405209
Hong, Hsu, Sannino, hep-ph/0406200
Dietrich, Sannino and Tuominen, hep-ph/0505059, hep-ph/0510217
Evans-Sannino, hep-ph/0512080
Gudnason, Kouvaris and Sannino, hep-ph/0603014
The Model: The generalized S-Theory
Inspired by progress in
Strong Interactions
`t Hooft - Large N
Ryttov and F.S. `05
Corrigan and Ramond `79
Larks
Kiritsis and Papavassiliou `90.
Helpful for MC ???
Relation with Super Yang-Mills
S-type
A-type
Armoni-Shifman-Veneziano
SYM
A-type:
QCD vacuum properties, spectrum and confinement/chiral symmetry,
finite temperature and density.
Armoni-Shifman-Veneziano,
Sannino-Shifman,
Sannino, (Finite Temperature. Chiral Symmetry vs Confinement)
Frandsen-Kouvaris-Sannino (Finite matter density)
Sannino-Schechter (..in progress)
N=1 Supersymmetric-Spectrum
Merlatti-Sannino
Feo-Merlatti-Sannino
S-type:
Composite Higgs from Higher Representations
Sannino
Not ruled out, LCH and DM
Dietrich-Tuominen-Sannino,
Hong-Hsu-Sannino, Sannino-Tuominen
Evans-Sannino
Gudnason, Kouvaris and Sannino
Phase Diagram for the S-Theory
Phase diagram as function of Nf and N. [Sannino-Tuominen]
For N=2,3,4,5 we have that Nf= 2
Nf=2 & N=2:
Minimal-Walking-Theory
Universal critical number of flavors in the adjoint: Nfc=2.075
S-parameter
• δ ~ 0.013 due to near conformal dynamics
[Sundrum-Hsu, Appelquist-Sannino].
•
The estimate for S in the S-type model is:
Model versus EWPData
150 GeV
68% contour
4th Lepton Family
Electron (m2) and Neutrino (m1) Dirac masses.
Standard Hypercharge Assignment
A natural LCH*
• Via trace anomaly and the behavior of the underlying beta
function near the chiral/conformal phase transition we show:
Phenomenology of a LCH
Associate Higgs production
Zerwekh 05
Spectrum
Techni-Mesons
Techni-Baryons
Electric Charge
An Effective Theory
Some Scenarios
Dark Side of the 5th Force
Nussinov
Barr, Chivukula and Farhi
Technibaryon, DD
Universe Charge Neutrality.
Chemical Equilibrium
Taking care of the Sphaleron Processes
Gudnason, Kouvaris, F.S. ph -0603014
Predictions and Outlook
• MH ~ light
• Fourth Family of Leptons around the Z mass.
• 6 light scalars will be observed.
• Electroweak baryongenesis.
Possible Strongly First order phase transition.
• Lattice Simulations are possible
• DM candidate-component
• Unification, Holography….
LHC
SUSY
TC
ED
Spectrum and Effective Theory I
Spectrum and Effective Theory II
Naturality
Small parameters stay small under radiative corrections.
The electron Mass
If set to zero the U(1)L× U(1)R forbids its regeneration
Naturalness begs an explanation of the origin of mass.
No conflict with any small value of the electron mass
Is the Higgs Natural?
No custodial symmetry protecting a scalar mass.
A mass appears even if ab initio is set to zero!
Hierarchy between the EW scale and the Planck Scale.
No!