The effect of an anomalous Higgs trilinear self-coupling on the h to gamma Z decay

Understand

We compute the two-loop effects induced by an anomalous Higgs trilinear self-coupling in the partial decay width h to gamma Z.

• The computation is performed using the anomalous coupling approach working in the unitary gauge and in a theory in which the anomalous coupling is generated via the addition to the scalar potential part of the Standard Model Lagrangian of an (in)finite tower of (Phi^dagger Phi)^n terms.
• The former computation is automatically finite while the latter requires the renormalization of the lowest order contribution.
• We discuss the renormalization conditions that should be employed in order to obtain the same result in the two approaches.