DOI: 10.1140/epja/i2002-10062-4
Evaluation of QCD sum rules for light vector mesons at finite density and temperature
S. Zschocke1, O.P. Pavlenko1, 2 and B. Kämpfer11 Forschungszentrum Rossendorf, PF 510119, 01314 Dresden, Germany
2 Institute for Theoretical Physics, 03143 Kiev - 143, Ukraine
Kaempfer@fz.rossendorf.de
(Received: 15 May 2002 / Revised version: 29 July 2002 / Published online: 10 December 2002)
Abstract
QCD sum rules are evaluated at finite nucleon densities
and temperatures to determine the change of mass parameters for
the lightest vector mesons
,
and
in a
strongly interacting medium. For conditions relevant for the
starting experiments at HADES we find that the in-medium mass
shifts of the
- and
-mesons are governed, within the
Borel QCD sum rule approach, by the density and temperature
dependence of the four-quark condensate. In particular, the
variation of the strength of the density dependence of the
four-quark condensate reflects directly the decreasing mass of
the
-meson and can lead to a change of the sign of the
-meson mass shift as a function of the density. In
contrast, the in-medium mass of the
-meson is directly
related to the chiral strange quark condensate which seems
correspondingly accessible.
14.40.Cs - Other mesons with S=C=0, mass < 2.5 GeV.
21.65.+f - Nuclear matter.
11.30.Rd - Chiral symmetries.
24.85.+p - Quarks, gluons, and QCD in nuclei and nuclear processes.
© Società Italiana di Fisica, Springer-Verlag 2002