Scaling of hadron properties at finite density in a chiral quark model with a glueball

Abstract

We investigate the density dependence of quark and gluon condensates in a chiral quark model with inclusion of a dilatation field. We consider a class of chiral quark models with an arbitrary local interaction between quark bilinears and the dilaton. Imposing chiral symmetry and an appropriate scale-transformation property we extract the leading finite-density corrections to some hadron properties (the pion mass and decay constant and other hadronic masses). We find that the low-density behavior of hadron properties is insensitive to the specific form of the interaction. Conditions for universal scaling of hadron properties at finite density are elaborated. We point out that universal scaling occurs only if the glueball mass is small compared to the mass of the chiral scalar meson. This condition is probably of a more general nature than the models studied here.