  We investigate the critical curve of the string tension sigma(T) as a function of temperature in quenched gauge invariant SU(3) lattice gauge theory. We extract sigma(T) from the colour averaged free energy of a static quark-antiquark pair. To compute the free energy, we utilize a pair of gauge invariant Polyakov loop and antiloop correlations, and apply the multihit procedure to enhance the signal to noise ratio. We find that the string tension departs from the zero temperature sigma(0) at T close to 0.5 Tc. We cover the relevant temperature range from 0.5 Tc up to the confinement temperature Tc using 57 different sets of pure gauge lattice configurations with four temporal extensions (4,6,8,12), different beta and a spatial volume of 48^3 in lattice units. 
Lattice QCD computation of the SU(3) String Tension critical curve