MONOPOLES, QUARK CONFINEMENT, AND SCREENING IN 4-DIMENSIONAL U(1) LATTICE GAUGE-THEORY

We present numerical calculations using the magnetic monopoles of four -dimensional U(1) lattice gauge theory to obtain the heavy quark poten tial. Using the cosine action we perform a conventional gauge field si mulation on a 16(4) lattice. We then use the DeGrand-Toussaint scheme for locating magnetic current in the lattice gauge field configuration s to obtain our monopole configurations. In addition to the heavy quar k potential we also calculate the potential between heavy external mon opoles. In the confined phase of quarks, we observe total screening be tween external monopoles. In the Coulomb phase of the quarks we find a partially screened Coulomb potential between external monopoles. Unde r the assumptions used to obtain the potential between external monopo les, we verify that the Dirac quantization condition holds for the pro duct of renormalized electric and magnetic charges.