Evaluation of QCD sum rules for light vector mesons at finite density and temperatureS. Zschocke1, O.P. Pavlenko1, 2 and B. Kämpfer1
1 Forschungszentrum Rossendorf, PF 510119, 01314 Dresden, Germany
2 Institute for Theoretical Physics, 03143 Kiev - 143, Ukraine
(Received: 15 May 2002 / Revised version: 29 July 2002 / Published online: 10 December 2002)
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