Ghost propagator and the Coulomb form factor from the lattice

We calculate the Coulomb ghost propagator G(|p|) and the static Coulomb potential V_C(|r|) for SU(2) Yang-Mills theory on the lattice. In view of possible scaling violations related to deviations from the Hamiltonian limit we use anisotropic lattices to improve the temporal resolution. We find that the ghost propagator is infrared enhanced with an exponent kappa_gh ~ 0.5 while the Coulomb potential exhibits a string tension larger than the Wilson string tension, sigma_C ~ 2 sigma. This agrees with the Coulomb "scaling" scenario derived from the Gribov-Zwanziger confinement mechanism.Comment: 23 pages, 5 figures. Some issues clarified and extended, references added. To appear in PR

SO(3) Yang-Mills theory on the lattice

We numerically investigate the phase structure of pure SO(3) LGT at zero and non-zero temperature in the presence of a Z2 blind monopole chemical potential. The physical meaning of the different phases, a possible symmetry breaking mechanism as well as the existence of an order parameter for the finite temperature phase transition are discussed.Comment: 3 pages, 2 figures LaTeX file. Uses espcrc2 style and amssymb package. Talk given at Lattice2002(nonzerot), Boston. Corrected version with one added referenc

SO(3) vs. SU(2) Yang-Mills theory on the lattice: an investigation at non-zero temperature

The adjoint SU(2) lattice gauge theory in 3+1 dimensions with the Wilson plaquette action modified by a Z(2) monopole suppression term is reinvestigated with special emphasis on the existence of a finite-temperature phase transition decoupling from the well-known bulk transitions.Comment: 13 pages, 9 figures. Based on contributions to CONFINEMENT 2003 and Lattice2003(topology). To be published in Proceedings of CONFINEMENT 2003, Tokyo, Japa