Computational challenges in the measurement of heavy-ion collision event characteristics with the atlas experiment at the LHC

Abstract

Heavy-ion collisions at extreme energies are expected to recreate conditions present in the early universe, producing a state of matter called the Quark Gluon Plasma (QGP). This state is characterized by very low viscosity resembling the properties of a perfect fluid. In such a medium, density fluctuations can easily propagate. In experimental practice, the size of these fluctuations is estimated by measuring the angular correlation of the particles produced. The aim of this paper is to present results of the measurements of the azimuthal anisotropy of charged particles produced in heavy-ion collisions with the ATLAS detector using the LHC Grid infrastructure for bulk processing of the data and resources available at the Tier-2 computing center for the final analysis stage.