Preview

PDF, English - main document Download (14MB) | Terms of use

Abstract

In relativistic heavy-ion collisions, a deconfined medium with high energy density is created, the quark-gluon plasma. Jets -- originating from primordial hard scatterings -- act as useful probes for the properties of this medium. As the initial partons traverse the quark-gluon plasma, they lose energy by interacting with the constituents of the medium. The study of this so called "jet quenching" yields insight into the properties of the medium.

By analyzing the angular correlations of jets with charged hadrons and comparing the per-trigger yields in PbPb and pp collisions (I_AA), one obtains information about the energy loss of jets in the medium. The study of these correlation functions for different orientations of the jet to the event plane allows for testing of the importance of dependence of the I_AA observable on the in-medium pathlength. This thesis presents measurements of the I_AA, measured with data from the ALICE detector at the LHC. As part of this thesis, an unfolding procedure for jet-hadron correlations was developed, showing in a closure test good agreement between the truth and re-weighted distributions. The measurement of the I_AA exhibits signatures of jet energy modifications, with an ordering of ratios with the event planes. Out-of-plane jets show higher yields than in-plane jets. However, evaluating the I_AA as function of the PbPb centrality suggests that fluctuations are the dominant effect for jet energy modifications over the path-length dependence.