Light neutrino and heavy particle exchange in 0νββ-decay

A simple and precise method is presented to compare contributions to neutrinoless double-beta decay (0νββ-decay) from heavy particle exchange and light Majorana neutrino exchange. This procedure makes no assumptions about the momentum transfer between the two nucleons involved in the 0νββ-decay process. It is shown that for a general particle physics model, the characteristic 0νββ-decay scale > 4.4 TeV when all the coupling constants are assumed to be natural and of O(1).