eingereicht am 01.06.2011 The Impact of Confining Dynamics on Chiral Symmetry Breaking

In this work we attempt to achieve a better understanding of the interrelation between the chiral phase transition and the deconfinement phase transition in QCD. We investigate the impact of confining dynamics on the spontaneous breaking of chiral symmetry which is directly related with the formation of a chiral condensate in the infrared. We start our analysis with a discussion of spontaneous chiral symmetry breaking and its relation to confinement in the framework of a low-energy model of QCD. To this end the fixed point structure of four-fermion interactions is investigated. In particular, we analyze how it is related to the confining dynamics in the gauge sector. We show that there exists a mechanism which dynamically locks the chiral phase transition to the deconfinement phase transition. This allows us to determine a locking window for the values of physical low-energy observables in which the two phase transitions lie close to each other. As a next step we augment our model study with dynamical gauge degrees of freedom to analyze chiral symmetry breaking in QCD theory. The study of the fixed point structure of four-fermion interactions exhibits a similar locking mechanism of the chiral and deconfinemen