Abstract :
I show that a particle structure in conformal field theory is incompatible with interactions. As a substitute one has particle-like excitations whose interpolating fields have in addition to their canonical dimension an anomalous contribution. The spectra of anomalous dimension is given in terms of the Lorentz invariant quadratic invariant (compact mass operator) of a conformal generator Rμ with pure discrete spectrum. The perturbative reading of R0 as a Hamiltonian in its own right, i.e., associated with an action in a functional integral setting naturally leads to the AdS formulation. The formal service role of AdS in order to access CQFT by a standard perturbative formalism (without being forced to understand first massive theories and then taking their scale-invariant limit) vastly increases the realm of conventionally accessible 4-dimensional CQFT beyond those for which one had to use Lagrangians with supersymmetry in order to have a vanishing Beta-function.