The Sounds of the QCD Phase Transition

Understand

Hydrodynamic description of a fireball produced in high energy heavy ion collisions has been recently supplemented by a very successful study of acoustic perturbation created by the initial state perturbations.

• We discuss sound produced at later stages of the collision, as the temperature drops below critical, $T<T_c$, and originated from the Rayleigh-type collapse of the QGP clusters.
• In certain analytic approximation we study distorted &#34;sound spheres&#34; and calculate modifications of the particle spectra and two-particle correlators induced by them.
• Unlike for initial state perturbations studied previously, we propose to look for those late-time sounds using rapidity correlations, rather than the azimuthal angles of the particles.