Equation of state in the quark-gluon plasma

Laermann E. Equation of state in the quark-gluon plasma. Nuclear Physics B Supplement. 1996;49(1-3):282-289.Results from quenched simulations of QCD at finite temperature are presented. We calculated pressure and energy density. With the standard Wilson action we worked on several large lattices, with temporal extent N-tau = 4, 6 and 8 and spatial extent N-sigma = 16 and 32. This enables to control finite lattice spacing effects and to extrapolate the results to the continuum limit. We find a deviation from ideal gas behaviour of about 15%, even at temperatures as high as T similar to 5T(c). a calculation of the critical temperature on lattices with temporal extent N-tau = 8 and 12 and the string tension on 32(4) lattices at the corresponding critical couplings is performed to fix the temperature scale. An extrapolation to the continuum limit yields T-c/root sigma = 0.629(3). These results are then compared to simulations with improved lattice actions. We can demonstrate that at high temperatures the cut-off effects can be reduced considerably