  Further evidence is presented for the existence of a non-confining phase at
weak coupling in SU(2) lattice gauge theory. Using Monte Carlo simulations with
the standard Wilson action, gauge-invariant SO(3)-Z2 monopoles, which are
strong-coupling lattice artifacts, have been seen to undergo a percolation
transition exactly at the phase transition previously seen using Coulomb-gauge
methods, with an infinite lattice critical point near $\beta = 3.2$. The theory
with both Z2 vortices and monopoles and SO(3)-Z2 monopoles eliminated is
simulated in the strong coupling ($\beta = 0$) limit on lattices up to $60^4$.
Here, as in the high-$\beta$ phase of the Wilson action theory, finite size
scaling shows it spontaneously breaks the remnant symmetry left over after
Coulomb gauge fixing. Such a symmetry breaking precludes the potential from
having a linear term. The monopole restriction appears to prevent the
transition to a confining phase at any $\beta$. Direct measurement of the
instantaneous Coulomb potential shows a Coulombic form with moderately running
coupling possibly approaching an infrared fixed point of $\alpha \sim 1.4$. The
Coulomb potential is measured to 50 lattice spacings and 2 fm. A short-distance
fit to the 2-loop perturbative potential is used to set the scale. High
precision at such long distances is made possible through the use of open
boundary conditions, which was previously found to cut random and systematic
errors of the Coulomb gauge fixing procedure dramatically. The Coulomb
potential agrees with the gauge-invariant interquark potential measured with
smeared Wilson loops on periodic lattices as far as the latter can be
practically measured with similar statistics data.
