Evolution of energy density fluctuations in A+A collisions

Abstract

Two-particle angular correlation for charged particles emitted in Au+Au collisions at the center-of-mass of 200 MeV measured at RHIC energies revealed novel structures commonly referred to as a near-side ridge. The ridge phenomenon in relativistic A+A collisions is rooted probably in the initial conditions of the thermal evolution of the system. In this study we analyze the evolution of the bumping transverse structure of the energy density distribution caused by fluctuations of the initial density distributions that could lead to the ridge structures. We suppose that at very initial stage of collisions the typical one-event structure of the initial energy density profile can be presented as the set of longitudinal tubes, which are boost-invariant in some space-rapidity region and are rather thin. These tubes have very high energy density comparing to smooth background density distribution. The transverse velocity and energy density profiles at different times of the evolution till the chemical freeze-out (at the temperature T=165 MeV) willbe reached by the system are calculated for sundry initial scenarios.Comment: Talk given at the The Sixth Workshop on Particle Correlations and Femtoscopy (WPCF2010), Kiev, September 14 - 18, 201