Abstract.
In this talk, we will discuss the application of causal perturbation theory to the recently debated diphoton decay of the Higgs boson. Perturbative quantum field theory, when naively applied, is known to be plagued with ultraviolet divergences. However, in the framework of causal perturbation theory one never encounters infinities. This approach originates from the observation that ultraviolet divergences can be traced back to the violation of causality, caused by ill-defined products of distributions at the same point. Renormalization is then formulated by extension of distributions. To begin with, we will present some challenges encountered in constructing the perturbative theory, motivating the transition to a distribution theoretic approach. Then, we will show that algebraic operations on functions do not trivially extend to distributions. With this in mind, the contention regarding the diphoton decay of the Higgs boson will be shown to result from a naive application of such an algebraic operation in the extension procedure.
(Unless this is a blackboard talk, the slides will be available here)