The minimal composite Higgs model and electroweak precision tests Original Research Article

A complete analysis of the electroweak precision observables is performed within a recently proposed minimal composite Higgs model, realized as a 5-dimensional warped compactification. In particular, we compute image and the one-loop correction to the ρ parameter. We find that oblique data can be easily reproduced without a significant amount of tuning in the parameters of the model, while image imposes a stronger constraint. As a consequence of the latter, some of the new fermionic resonances must have mass around 4 TeV, which corresponds to an electroweak fine tuning of a few percent. Other resonances, such as image, can be lighter in sizeable portions of the parameter space. We discuss in detail the origin of the image constraint and we suggest several possible avenues beyond the minimal model for weakening it.