Effective restoration of the U(A)(1) symmetry in the SU(3) linear sigma model

The effective restoration of the chiral U(A)(1) symmetry in strong interactions is studied using the linear chiral SU(3)xSU(3) model at finite temperatures. We find that the disappearance of the chiral anomaly causes a considerable change in the meson mass spectrum. We propose several signals for detecting this chiral phase in ultrarelativistic heavy-ion collisions: The eta/pi(0) ratio is enhanced by an order of magnitude, the a(0) is suppressed in the K&Kmacr; mass spectrum, and the scalar kappa meson appears as a peak just below the K(*)(892) in the invariant piK mass spectrum.