CPT

Calendar of Physics Talks Vienna

Infrared fixed points of QCD
Speaker:Kai Schwenzer (Universit├Ąt Graz)
Abstract:The speaker will discuss the infrared fixed point structure of Landau gauge QCD and the importance of these fixed points for physical phenomena like the confinement of quarks and chiral symmetry breaking. In addition to the known singularities in the uniform scaling limit, where all external momenta of a correlation function tend to zero, the vertices feature also kinematic singularities when only a single gluon momentum vanishes. In the case of the quark-gluon vertex these soft singularities are non-perturbatively enhanced and provide a mechanism for the confinement of static color sources in quenched QCD. In contrast, when dynamical chiral quarks are present the theory proves to be non-confining. Since the unquenched, physical case depends on the current quark mass scales and lies in between these limiting cases, this provides the chance to describe string breaking and hadronization.
Date: Tue, 09.09.2008
Time: 14:00
Location:SEM136, ITP, TU Wien, Wiedner Hauptstr. 8-10, 1040 Wien, 10. OG
Contact:rebhana ├Ąt tph.itp.tuwien.ac.at