Emergent electroweak symmetry breaking with composite W, Z bosons

Abstract

We present a model of electroweak symmetry breaking in a warped extradimension where electroweak symmetry is broken at the UV (or Planck) scale. Anunderlying conformal symmetry is broken at the IR (or TeV) scale generatingmasses for the electroweak gauge bosons without invoking a Higgs mechanism. Bythe AdS/CFT correspondence the W,Z bosons are identified as composite states ofa strongly-coupled gauge theory, suggesting that electroweak symmetry breakingis an emergent phenomenon at the IR scale. The model satisfies electroweakprecision tests with reasonable fits to the S and T parameter. In particularthe T parameter is sufficiently suppressed since the model naturally admits acustodial SU(2) symmetry. The composite nature of the W,Z-bosons provide anovel possibility of unitarizing WW scattering via form factor suppression.Constraints from LEP and the Tevatron as well as discovery opportunities at theLHC are discussed for these composite electroweak gauge bosons.