Towards a Realistic Model of Higgsless Electroweak Symmetry Breaking

Abstract

We present a 5D gauge theory in warped space based on a bulk SU (2) L × SU (2) R × U (1) B−L gauge group where the gauge symmetry is broken by boundary conditions. The symmetry breaking pattern and the mass spectrum resembles that in the standard model (SM). To leading order in the warp factor the ρ parameter and the coupling of the Z (or equivalently the S-parameter) are as in the SM, while corrections are expected at the level of a percent. From the AdS/CFT point of view the model presented here can be viewed as the AdS dual of a (walking) technicolor-like theory, in the sense that it is the presence of the IR brane itself that breaks electroweak symmetry, and not a localized Higgs on the IR brane (which should be interpreted as a composite Higgs model). This model predicts the lightest W , Z and γ resonances to be at around 1.2 TeV, and no fundamental (or composite) Higgs particles.

Mesons in gauge/gravity duals

“…It is worth remarking that very similar ideas to these models have inspired the field of Higgsless electroweak models [256,257] and their deconstructed [258,259] partners for example in [260].…”

Randall–Sundrum reality at the LHC

“…In order to suppress unwanted higher dimensional operators, which are not sufficiently suppressed by the TeV-scale cutoff on the IR brane in the RS1 model, SM gauge fields [2,3,4,5] and fermions [6,7] are considered to propagate in the bulk space. In this new setup [2,3,4,5,6,7,8,9,10,11,12,13,14,15,16], denoted as the RS model, RS can address both the hierarchy problem and fermion mass hierarchies. From the electroweak precision measurements and various flavor physics, the new Kaluza-Klein (KK) modes of the bulk SM fields are constrained to be heavier than a few TeV [2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23].…”

Field theory on multithroat backgrounds

“…Large and warped extra dimensions have been proposed to alleviate the hierarchy problem [1,2], small extra dimensions can give rise to novel approaches to GUT model building [3], universal extra dimensions can give new dark matter candidates [4], and even new mechanisms for electroweak symmetry breaking can be found using extra dimensions [5][6][7]. In most of these models, only the simplest possible topologies of the extra dimensional space have been assumed: a single (or sometimes two) extra dimensions compactified on a circle (or torus), or a very simple orbifold like S 1 =Z 2 or T 2 =Z 2 .…”