Perturbativity Constraints in BSM Models

Understand

Phenomenological studies performed for non-supersymmetric extensions of the Standard Model usually use tree-level parameters as input to define the scalar sector of the model.

• This implicitly assumes that a full on-shell calculation of the scalar sector is possible - and meaningful.
• However, this doesn't have to be the case as we show explicitly at the example of the Georgi-Machacek model.
• This model comes with an appealing custodial symmetry to explain the smallness of the $\rho$ parameter.