Blastwave parameterization for Pb-Pb collisions at sNN = 2.76 TeV and sNN = 5.02 TeV

Abstract

In heavy-ion collisions an extremely hot and dense state of matter, known as the quark-gluon plasma (QGP), is created. This plasma immediately cools due to a rapid expansion and the quarks and gluons form hadrons that are detected by dedicated detectors. The QGP can be described by various models, one of which is known as the blast-wave model. The blast-wave model aims to parameterize the freeze-out phase, the moment particles that are produced in the collision freely stream towards the detector, of the QGP with the use of eight parameters. In this thesis data from the ALICE collaboration is used. The data describe the centrality dependence of particle production of charged pions and kaons and (anti)protons as well as the transverse momentum dependence of the harmonic flow coefficients v2 and v3 in Pb-Pb collision at s_NN = 2.76 TeV and s_NN = 5.02 TeV. The data are fitted with the blast-wave model and from the fit the freeze-out temperature, average transverse velocity of the system and the parameter rho2, related to the elliptic flow of the system, are determined. When analysing these parameters it was found that the freeze-out temperature is not affected by the energy difference, whereas the average transverse velocity of the system does indicate a modest increase with energy.