A Skyrmion Fluid

Abstract

A fluid of Skyrmions coupled to the dilaton field and the $ø$ meson field is considered. A mean field theory is developed in which the dilaton and the $ø$ field acquire a mean value determined by the Skyrmions. The influence of the background fields on the Skyrmion profile is determined and consequently the scaling properties of the Skyrmion follow. The model obeys chiral invariance and scale invariance broken only by the dilaton trace anomaly potential. The dilaton plays the role of the scalar field as in the $\s + ø$ model. The dilaton potential is augmented by terms that do not spoil the trace anomaly while allowing a fit to nuclear matter properties. The phase diagram of the model shows unique features, like a lack of solutions for certain densities and temperatures, signalling the appearance of a new phase that can not be described in terms of Skyrme baryons.