Quark and gluon condensates in nuclear matter
Abstract
Quark and gluon condensates in nuclear matter are studied. These inmedium condensates may be linked to a wide range of nuclear phenomena and are important inputs to QCD sumrule calculations at finite density. The HellmannFeynman theorem yields a prediction of the quark condensate that is model independent to first order in the nucleon density. This linear density dependence, with slope determined by the nucleon σ term, implies that the quark condensate is reduced considerably at nuclear matter saturation densityit is roughly 2550 % smaller than the vacuum value. The trace anomaly and the HellmannFeynman theorem lead to a prediction of the gluon condensate that is model independent to first order in the nucleon density. At nuclear matter saturation density, the gluon condensate is about 5% smaller than the vacuum value. Contributions to the inmedium quark condensate that are of higher order in the nucleon density are estimated with meanfield quarkmatter calculations using the NambuJonaLasinio and GellMannLévy models. Treatments of nuclear matter based on hadronic degrees of freedom are also considered, and the uncertainties are discussed.
 Publication:

Physical Review C
 Pub Date:
 April 1992
 DOI:
 10.1103/PhysRevC.45.1881
 Bibcode:
 1992PhRvC..45.1881C
 Keywords:

 21.65.+f;
 12.40.y;
 24.85.+p;
 Nuclear matter;
 Other models for strong interactions;
 Quarks gluons and QCD in nuclei and nuclear processes