  We perform lattice simulations in pure-SU(2) Yang-Mills theory to investigate
how the infrared behavior of electric and magnetic gluon propagators in Landau
gauge is affected by temperature. We consider the largest lattices to date, in
an attempt to keep systematic errors under control. Electric and magnetic
screening masses are calculated through an Ansatz from the zero-temperature
case, based on complex-conjugate poles for the momentum-space propagators. As
recently reported in [1], we find good fits to the proposed form at all
temperatures considered, with different ratios of real to imaginary part of the
pole masses for the longitudinal (electric) and transverse (magnetic)
propagators. The behavior of the magnetic propagator D_T(p) is in agreement
with the dimensional-reduction picture, showing infrared suppression (with a
turnover in momentum) and violation of spectral positivity at all nonzero
temperatures considered. The longitudinal propagator D_L(p) appears to reach a
plateau at small momenta and is subject to severe finite-Nt effects around the
critical temperature Tc. As a consequence, only lattices with temporal extent
Nt > 8 seem to be free from systematic errors. After these errors are removed,
the infrared-plateau value is considerably reduced around the transition and
the sharp peak observed previously for this quantity at Tc is no longer
present. The resulting infrared behavior for D_L(p) at Tc is essentially the
same as for 0.5Tc . An investigation of the temperature range between 0.5Tc and
Tc reveals that a less pronounced (finite) peak may occur at smaller
temperatures, e.g. T ~ 0.9Tc.
