Separating perturbative and non-perturbative contributions to the plaquette

We try to separate the perturbative and non-perturbative contributions to the plaquette of pure SU(3) gauge theory. To do this we look at the large-n asymptotic behaviour of the perturbation series in order to estimate the contribution of the as-yet uncalculated terms in the series. We find no evidence for the previously reported Lambda(2) contribution to the gluon condensate. Attempting to determine the conventional Lambda(4) condensate gives a value similar to 0.03(2) GeV4, in reasonable agreement with sum rule estimates, though with very large uncertainties.