Dimensional reduction and screening masses in pure gauge theories at finite temperature

We studied screening masses in the equilibrium thermodynamics of SU(2) and SU(3) pure gauge theories on the lattice. At a temperature of 2T<SUB>c</SUB> we found strong evidence for dimensional reduction in the non-perturbative spectrum of screening masses. Mass ratios in the high-temperature SU(3) theory are consistent with those in the pure gauge theory in three dimensions. At the first-order SU(3) phase transition we report the first measurement of the true scalar screening mass