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Informal Pizza SeminarHiggless Electroweak Symmetry BreakingChristophe GrojeanCEA Saclay & University of MichiganIdentifying the mechanism of Electroweak Symmetry Breaking is one of the major quests of particle physics for the next coming years. The usual Higgs mechanism is not very satisfactory or at least incomplete because of the quantum instability driven by the radiative corrections in the scalar potential. The existence of a Higgs boson is usually warranted by some theoretical arguments (unitarity, renormalizabilty...) that I will recall before explaining how they can be evaded. Then I will introduce a model of Electroweak Symmetry Breaking that does not involve any Higgs field at low energy and where electroweak breaking is dynamically triggered by boundary conditions. A custodial symmetry ensures that the spectrum and the couplings are identical to the Standard Model ones. I will also explain how to give masses to quarks and leptons without Yukawa couplings. I will present the experimental signatures of the model as for instance the existence around 500 GeV-1 TeV of spin one excitations with the W and Z quantum numbers. Finally, I will discuss the issue of electroweak precision tests and various experimental constraints.
Wednesday, July 7th 2004, 13:00
Ernest Rutherford Physics Building, room 326 |