Force between static charges and universality in lattice QCD

We present Monte Carlo results for the force between static quarks on a large (${16}^3$ × 32) lattice and with high statistics, obtained by using an action which combines terms in the fundamental and adjoint representations of SU(3). We discuss universality with respect to the choice of the action, which appears to be well verified, and propose a phenomenological formula for the force as a function of separation.