PUB - Publikationen an der Universität Bielefeld

In this work we have studied gluon field distributions around a static quark and anti-quark pair at high temperature by means of lattice simulations of Quantum Chromodynamics in the quenched approximation. Measuring the electric and magnetic components of the gluon field at temperatures close to the critical temperature of the phase transition from the confined to the deconfined phase of QCD, we were able to see how longitudinal and transverse profiles of the flux tube between the static quark and anti-quark pair change with temperature. Flux tube profiles are extracted from correlations of a plaquette with Polyakov loops by varying the distance and the orientation of the plaquette with respect to the Polyakov loops. The parallel electric field component turned out to be larger than the other three field components, which are approximately equal, at all a fixed constant quark and anti-quark separation and temperatures. This tells us that, as at zero temperature, the force that comes from the field strength that is oriented along the axis connecting the quark and anti-quark pair and trying to bind a quark and an antiquark together is chromo-electric. By exploring the temperature dependence of the longitudinal profiles we were able to show that the field strength distributions approach the one of a single isolated quark when the rising temperature approaches the critical temperature. From the transverse profiles at various temperatures we further have found that the physical width of the flux tube decreases when the temperature increases. The decrease with increasing temperature of the width and the height of the transverse profiles at the same time shows the gradual disappearance of the flux tube when the temperature approaches the critical temperature of the phase transition from the confined to the deconfined phase. The string tension obtained from our data agrees with the continuous behaviour of the second order phase transition of SU(2) gauge theory.