THE TOPOLOGICAL SUSCEPTIBILITY AND LATTICE UNIVERSALITY

We study the topological susceptibility χ on the lattice, using four different actions from the mixed fundamental adjoint family. To measure χ we employ on the one hand a field theoretic approach, which requires the calculation of lattice-induced renormalization functions, to be applied to the raw Monte Carlo data; on the other hand we use a method of slow cooling. The two methods provide cross-checks on each other and are found to give consistent results. We also measure with the same actions the quadratic gluon condensate G2 and the string tension σ; the latter can be measured with very small statistical flutuations using cooling. The dimensionless ratios χ/G2 and σ2/G2 must be the same for all actions and we thus use them to test universality, independently of any prescriptions for the values of ΛQCD or for the scaling region in each action. We also carry out checks of three such prescriptions for a comparative evaluation. © 1980.