Dresden 2000 – scientific programme

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T: Teilchenphysik

T 408: Feldtheorie

T 408.5: Talk

Tuesday, March 21, 2000, 17:30–17:45, H\,204

Difference of SO(3) and SU(2) gauge theories at high temperatures — •Kurt Langfeld and Hugo Reinhardt — Institut für Theoretische Physik, Universität Tübingen, Auf der Morgenstelle 14, D-72076 Tübingen

For revealing the significance of the center component of the links in SU(2) lattice gauge theory we investigate the high temperature limit of SU(2) and SO(3) lattice gauge theory, respectively. In particular, we study in either case the behavior of the Stefan-Boltzmann constant, which merely counts the degrees of freedom of the high temperature phase. It has been known for years that the Stefan-Boltzmann constant in the SU(2) case is too small to cope with the demand from a continuum analysis assuming three gluon degrees of freedom. By contrast, our numerical data in the case of the SO(3) gauge theory perfectly reproduce the continuum expectation. We therefore show that SU(2) and SO(3) lattice gauge theories represent different quantum theories in the continuum limit, at least at high temperatures. We attribute the difference in the Stefan-Boltzmann constant to vortices which are known to be physical degrees of freedom of SU(2) gauge theory [1].

[1] K. Langfeld, O. Tennert, M. Engelhardt and H. Reinhardt,
Phys. Lett. B452 (1999) 301.