scikit-hep/vector expects fields to be named in a very specific way in order to make objects behave like 4-vectors. It also looks at fields only and not behaviors. Defining the following behavior for example like we do for Delphes does not help it. Vector only looks inside fields and not behaviors.

    @property
    def pt(self):
        return self["PT"]

We should therefore ensure that all the fields are aliased properly at the schema level. In this example, the delphes schema should alias PT -> pt at the schema level.