One light composite Higgs boson facing electroweak precision tests

Abstract

We study analytically and numerically the bounds imposed by the electroweak precision tests on a minimal composite Higgs model. The model is based on spontaneous SO(5)/SO(4) breaking, so that an approximate custodial symmetry is preserved. The Higgs arises as a pseudo-Goldstone boson at a scale below the electroweak symmetry breaking scale. We show that one can satisfy the electroweak precision constraints without much fine-tuning. This is the case if the left-handed top quark is fully composite, which gives a mass spectrum within the reach of the LHC. However a composite top quark is strongly disfavoured by flavour physics. The alternative is to have a singlet top partner at a scale much lighter than the rest of the composite fermions. In this case the top partner would be light enough to be produced significantly at the LHC.

15 pages, 4 figures; v2: figures and discussion improved, references added; v3: minor changes, final version to appear in PRD

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• The Strongly-Interacting Light Higgs
• Light custodians in natural composite Higgs models
• Light Kaluza-Klein States in Randall-Sundrum Models with Custodial SU(2)
• The Higgs boson from an extended symmetry
• Discovering the top partners at the LHC using same-sign dilepton final states
• Realistic Composite Higgs Models
• Vector-like quarks in a composite Higgs model
• TASI 2004 Lectures: To the Fifth Dimension and Back

Cited by in corpus (25)

• The Composite Nambu-Goldstone Higgs
• Composite Higgses
• Precision Measurements of Higgs Couplings: Implications for New Physics Scales
• The Discrete Composite Higgs Model
• Physics at the e+ e- Linear Collider
• Tasi 2009 lectures: The Higgs as a Composite Nambu-Goldstone Boson
• Strong Higgs Interactions at a Linear Collider
• A Strong Sector at the LHC: Top Partners in Same-Sign Dileptons
• Vector-like Bottom Quarks in Composite Higgs Models
• Precision Tests and Fine Tuning in Twin Higgs Models
• Gluon-fusion Higgs production at NNLO for a non-standard Higgs sector
• The S parameter for a Light Composite Higgs: a Dispersion Relation Approach
• Exploring T and S parameters in Vector Meson Dominance Models of Strong Electroweak Symmetry Breaking
• The Natural Composite Higgs
• E6 inspired composite Higgs model
• Broad composite resonances and their signals at the LHC
• Partially Supersymmetric Composite Higgs Models
• New theories for the Fermi scale
• A UV Complete Compositeness Scenario: LHC Constraints Meet The Lattice
• LHC signatures of neutral pseudo-Goldstone boson in the E6CHM
• $Hb\bar{b}$ production in Composite Higgs Models
• Fine Tuning in the Holographic Minimal Composite Higgs Model
• Baryon asymmetry generation in the E6CHM
• Higgs Physics Beyond the Standard Model
• The Electroweak Symmetry Breaking Riddle