DOI 10.1007/s100520000461
Thermal QCD sum rules in the
channel revisited
R. Hofmann - Th. Gutsche - A. Faessler
Institut für Theoretische Physik,
Universität Tübingen,
Auf der Morgenstelle 14,
72076 Tübingen,
Germany
Received: 16 November 1999 / Revised version: 20 May 2000 /
Published online:
23 October 2000
- Springer-Verlag 2000
Abstract
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