# Field content and symmetry groups of Minimal Composite Higgs Models

I'm trying to teach myself the Composite Higgs Model, both its theory and its LHC phenomenology (particularly the 4DCHM). Unfortunately, I'm struggling; the literature is contradictory and/or omits basic details (?!). I have a few related questions, that should help me get started understanding the models,

1. What are the extra symmetry groups in the 4DCHM/minimal CHM? Is the $SO(5)/SO(4)$ approximate symmetry global or local? If it is local (as this source suggests hep-ph/1302.2371v2), why aren't the Goldstone bosons (the four Higgs dof) eaten by the broken generators?
2. What is the extra field content in the 4DCHM/minimal CHM? What extra gauge or fermion fields are present? Are they composite from the strong dynamics or fundamental?
3. How are the SM, new fundamental, new composite and new gauge fields arranged into representations of the extra symmetry groups?

Any help or sources of information would be appreciated.

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