Jet quenching in heavy-ion collisions at LHC with CMS detector

The collision of highly relativistic nuclei can produce a volume of high energy densitywhich can be used to learn about the behavior of quantum chromodynamics (QCD)at extreme conditions, such as those of the universe at times before and during theformation of hadrons out of quarks and gluons. This thesis presents experimental√studies of jet-quenching phenomena in PbPb collisions at sN N = 2.76 TeV, with afocus on the study of the energy-loss, namely the analysis of correlations of jet pairsas measured by the CMS detector at LHC. The implications of the results are discussed by comparison of simple models with data. It is observed that the geometricalconfiguration of the dijets and the nuclear collision region plays an important role inthe correlations between the jets, and the set of CMS results reviewed can illustratethe dependence of the amount of lost energy on the length of the traversed medium.Thesis Supervisor: Prof. Dr. Gunther M. RolandTitle: Professor