Skip to Main content Skip to Navigation

Measurement of Z-boson and J/ψ Production in p-Pb and Pb-Pb Collisions at √sNN = 5.02 TeV with ALICE at the LHC

Abstract : Ultra relativistic heavy-ion collisions are considered as a unique tool to produce, in the laboratory, thehot and dense strongly-interacting medium, the Quark-Gluon Plasma (QGP). This thesis is dedicated to the studyof two powerful probes, the J/ψ and Z-boson, that can help reaching a better understanding of the properties of theQGP.An important observable to study the QGP formation in heavy-ion collisions is the measurement of the J/ψproduction. The sizes of the different effects that can enhance or suppress this production vary with the collisionenergy. In this thesis, the J/ψ production is measured in Pb-Pb collisions at √sNN = 5.02 TeV using mainly themuon spectrometer of the ALICE detector. The J/ψ nuclear modification factor is presented as a function ofcollision centrality, rapidity and transverse momentum (pT). In addition, results on the J/ψ average pT and squaredaverage pT are also obtained. The comparison between the results and various theoretical calculations suggests thatthe J/ψ production is affected in the medium by an interplay between dissociation and regeneration mechanisms.In heavy-ion collisions, the initial state of the collision can affect the results even in the absence of the QGP.Understanding and quantifying such effects is crucial in order to separate them from the ones caused by thepresence of the QGP. One of these effects is the nuclear modification of the parton distribution functions (PDFs).The measurement of Z-boson production in heavy-ion collisions is a powerful tool to study the nuclearmodification of PDFs since it is not affected by the presence of the strongly-interacting medium. The second partof this thesis is devoted to measure the Z-boson production, for the first time with ALICE, in p-Pb and Pb-Pbcollisions at √sNN = 5.02 TeV. In Pb-Pb collisions where the precision of the measurement is higher, the agreementbetween data and theoretical calculations is better when the latter take into account the nuclear modification of thePDFs.
Complete list of metadata

Cited literature [145 references]  Display  Hide  Download
Contributor : Abes Star :  Contact
Submitted on : Wednesday, January 24, 2018 - 12:11:09 PM
Last modification on : Wednesday, October 14, 2020 - 3:42:26 AM


Version validated by the jury (STAR)


  • HAL Id : tel-01691725, version 1



Mohamad Tarhini. Measurement of Z-boson and J/ψ Production in p-Pb and Pb-Pb Collisions at √sNN = 5.02 TeV with ALICE at the LHC. High Energy Physics - Experiment [hep-ex]. Université Paris-Saclay, 2017. English. ⟨NNT : 2017SACLS283⟩. ⟨tel-01691725⟩



Record views


Files downloads