Further investigation of massive Landau-gauge propagators in the infrared limit

Abstract

We investigate how the infrared behavior of electric and magnetic gluon propagators in Landau gauge is affected by temperature. More precisely, we perform large-lattice simulations in pure SU(2) gauge theory around the transition temperature Tc and study the longitudinal (electric) and transverse (magnetic) gluon propagators in momentum space, proposing the calculation of screening masses through an Ansatz from the zero-temperature case. Going from zero to nonzero temperature, we see that the longitudinal gluon propagator DL(p) is enhanced, with an apparent plateau value in the infrared, while the transverse propagator DT (p) gets progressively more infrared-suppressed, with a clear turnover in momentum at all nonzero temperatures considered. Our data allow us to associate what was previously seen as a peak in the infrared value of DL(p) at Tc to severe finite-size effects along the temperature direction. In particular, a temporal lattice extent Nt ≥ 8 seems to be needed to study the electric sector around the transition. Once these systematic errors are eliminated, the infrared behavior of the longitudinal propagator appears to be rather independent of the temperature below the transition. Above Tc, the infrared value of DL(p) starts to decrease monotonically with the temperature.