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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.
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The Niels Bohr Institute Dynamical Electroweak Breaking @ LHC Francesco Sannino MC-Workshop Frascati - 2006
….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 aspects of the SM ..and Beyond New as Origin of Mass for the weak gauge bosons, quarks … Understanding Strong Dynamics
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: S = 0.07±0.10 Dutta, Hagiwara and Yan ph/0603038.Weaken constraints
Superconductivity Macroscopic-Screening Non-Relativistic SM-Screening Relativistic
Meissner-Mass Static Vector Potential Weak-GB-Mass Hidden structure ????
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 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 FCNC Operators PNG Masses SM-Fermion Masses should be sufficiently larger than to reduce FCNC. Progress: Appelquist, Christensen, Piai, Shrok
Near Conformal Properties Holdom Appelquist Miransky, Yamawaki Cohen and Georgi…
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 Near conformal for N=2 means Nf/2=4 which yields: Experimentally S = 0.07±0.10 Appelquist - Sannino
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
`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 4th Lepton Family 68% contour 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 Electric Charge Techni-Baryons
Dark Side of the 5th Force Nussinov Barr, Chivukula and Farhi Technibaryon, DD Universe Charge Neutrality. Chemical Equilibrium Taking care of the Sphaleron Processes
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
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!