SCREENING OF THE CONFINEMENT POTENTIAL IN THE SU(2) LATTICE GAUGE-THEORY WITH SCALAR MATTER

Using the SU (2) Higgs system with dynamical scalar matter fields as a model for analyzing screening properties of the confining potential in gauge theories, we examine the Wilson loop W (T, R) and the gauge invariant 2-point function G(T, R) by Monte Carlo simulations on a 164 lattice. For small values of the hopping parameter k these quantities show non-asymptotic area law behavior which changes to asymptotic perimeter law behavior as k increases. Close to the Higgs phase transition we find an indication that both these asymptotic and nonasymptotic terms are present simultaneously within the lattice at different distances R and T and that the breaking of the confining flux tube by matter pair production occurs within the lattice. Introducing an appropriate ansatz for W(T, R) and G(T, R), respectively, we determine in this complex situation the string tension, the screening energy of the external sources, and the order parameter introduced by Fredenhagen and Marcu. © 1990 Springer-Verlag.