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Atominstitut Office at Freihaus

Ms. Sonja Schuh
TU Wien, Freihaus, Turm B, 6.OG
Wiedner Hauptstraße 8-10
1040 Wien, Austria
Tel.: +43 1 58801 142101
Fax: +43 1 58801 14299
E-mail: institut@kph.tuwien.ac.at

Opening Hours for Students:
Monday to Friday 9:30-11:30 and 12:30-15:30

Announcements

Deanery at Freihaus

Faculty of Physics

TU Wien, Freihaus, Turm B, 5. OG
Wiedner Hauptstraße 8-10
1040 Wien, Austria

Decan: Ao.Univ.Prof. Dipl.-Ing. Dr.techn. Helmut Leeb
Responsibility: diploma/doctoral examination, approval for doctoral studies, implementation of curriculum, all matters for master studies of material sciences

Vice Decan: Privatdoz. Dipl.-Ing. Dr.techn. Herbert Balasin
Responsibility: recognition and change of courses, approval for master studies, grants

Lattice QCD and General Quantum Field Theory

QCD is the widely accepted theory for the strong interaction. It is formulated in the framework of quantum field theory, which describes the fundamental interactions by exchange particles. Predictive calculations are possible for phenomena at high energies, or equivalently, very short distances. Here the coupling constant is weak and perturbation theory is a useful tool. How the quarks are bound in the hadrons, however, is controlled by the large-scale behaviour of the coupling, which increases with distance. For such questions, lattice QCD is an indispensable technique, for example to compute the hadron spectrum.

Lattice QCD is QCD formulated on a discrete Euclidean spacetime lattice. LQCD preserves the fundamental character of QCD but realizes important improvements: first, the discrete spacetime lattice serves as a "regulator". A general feature of quantum field theories, and also QCD, is the occurrence of singularities. On the lattice, as long as the lattice constant a is finite, these singular quantities are rendered finite. Furthermore, the limit a → 0 is well-defined and leads to finite, so-called renormalized physical quantities. In contrast to the continuum, calculations can be performed even for high values of the coupling constant. Another advantage is that LQCD can be simulated numerically on the computer, using methods similar to those used in statistical mechanics.

Figure: Action density of the QCD vacuum from Visualizations of Quantum ChromodynamicsCentre for the Subatomic Structure of Matter (CSSM) and Department of Physics, University of Adelaide, 5005 Australia. Copyright © 2003, 2004