Anisotropic Flow Measurements in ALICE at the Large Hadron Collider

Abstract

Anisotropic flow is one of the observables which is sensitive to the properties of the created hot and dense system in heavy-ion collisions. In noncentral heavy-ion collisions the initial volume of the interacting system is anisotropic in coordinate space. Due to multiple interactions this anisotropy is transferred to momentum space, and is then quantified via so-called flow harmonics vn. In essence, anisotropic flow analysis is the measurement of flow harmonics vn. In this thesis a newly developed method for anisotropic flow analysis, called Q-cumulants, is presented in detail. The improvements over other existing and previously used methods are discussed. Q-cumulants are used to perform anisotropic flow measurements in ALICE experiment at the Large Hadron Collider (LHC), and the results of these measurements are presented in the thesis. In particular, centrality and transverse momentum dependence for elliptic flow (v2) are shown, as well as for few higher harmonics (v3, v4, v5). These results suggest that the created matter in heavy-ion collisions at LHC behave as a strongly coupled liquid