Münster 2002 – scientific programme

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HK: Physik der Hadronen und Kerne

HK 9: Poster Session: Theory

HK 9.2: Poster

Tuesday, March 12, 2002, 10:30–12:45, Foyer Chemie

Debye Screening At Finite Temperature, Revisited — •Roland A. Schneider — Physik-Department, Technische Universität München, Garching, Germany

We present a new, alternative way to calculate the screening of the static potential between two charges in (non)abelian gauge theories at high temperatures by looking at the magnetic properties of the vacuum. The Hard Thermal Loop (HTL) gluon and photon Debye masses are recovered in a first, though incomplete approximation. In QED, the complete calculation to order α exhibits an interesting cancellation of terms, resulting in a logarithmic running α(T). Debye screening is then caused by the modified index of refraction of the vacuum. In QCD, an unphysical Landau pole occurs that arises, as in more sophisticated thermal renormalization group calculations, from the wrong sign of the gluon contribution.
Supported in part by BMBF and GSI.