FG 465: Gitter-Hadronen-Phänomenologie - Teilprojekt 2: Topological Gauge Field Structure of Lattice QCD in the Ground State and at Non-Vanishing Temperature

The purpose of the project is to pursue thorough investigations of the topological structure of lattice QCD emphasizing the effects of dynamical quarks. The cases of the ground state (T=0) as well as of the thermal equilibrium at temperatures near the deconfinement and chiral phase transition (T=Tc) are studied and compared. The investigationen will rely on large volume, zero-temperature gauge field configurations obtained by the Forschergruppe ant those available, thanks to the QCDSF collaboration with UKQCD. Additional less extensive Hybrid Monte Carlo simulations are required for the finite T-case. With respect to a semi-classical view of the QCD vacuum we are going to investigate the relevance of dissociated non- Abelian monopoles or calorons (Kraan-van Baal Solutions) in pure gauge theory and - at a later stage - in full QCD. With respect to an effective long-range description of non-perturbative QCD the Abelian and centre degrees of freedom (monopoles and vortices) are studied in suitable gauges in order to understand their mutual relation and their correlation with semi-classical excitations as mentioned above. We shall focus on the local correlation of fermionic degrees of freedom with monpole and vortex excitations, the formation and breaking of flux tubes between static quarks and the computation of order parameters of the condensation of those topological excitations.