Thermal QCD sum rules in the channel revisited
R. Hofmann - Th. Gutsche - A. Faessler
Institut für Theoretische Physik,
Auf der Morgenstelle 14,
Received: 16 November 1999 / Revised version: 20 May 2000 /
Published online: 23 October 2000 - Springer-Verlag 2000
From the hypothesis that at zero temperature the square root of the spectral continuum threshold s0 is linearly related to the QCD scale we derive in the chiral limit and for temperatures considerably smaller than scaling relations for the vacuum parts of the Gibbs averaged scalar operators contributing to the thermal operator product expansion of the current-current correlator. The scaling with , s0 being the T-dependent perturbative QCD continuum threshold in the spectral integral, is simple for renormalization group invariant operators, and becomes nontrivial for a set of operators which mix and scale anomalously under a change of the renormalization point. In contrast to previous works on thermal QCD sum rules with this approach the gluon condensate exhibits a sizable T-dependence. The -meson mass is found to rise slowly with temperature which coincides with the result found by means of a PCAC and current algebra analysis of the correlator.
Copyright Società Italiana di Fisica, Springer-Verlag 2000