Disputation: Olja Dordic
Doctoral candidate Olja Dordic at the Department of Physics, Faculty of Mathematics and Natural Sciences, is defending the thesis
"Charged dihadron azimuthal correlations in pp and Pb-Pb collisions, measured with the ALICE detector"
for the degree of Philosophiae Doctor.
The University of Oslo is closed. Olja's PhD defence will therefore be fully digital and streamed directly using Zoom. The host of the session will moderate the technicalities while the chair of the defence will moderate the disputation.
Conferral summary / Kreeringssammendrag
Denne avhandlingen benytter korrelasjonsfunksjoner, konstruert for alle ladde hadroner som passerer kvalitetskravene for enkeltspor. Funn for to forskjellige kollisjonssystemer, proton-protonkollisjoner ved √s = 2.76 og 7 TeV, og bly-bly-kollisjoner ved √sNN = 2.76 TeV, blir sammenlignet. De oppnådde resultatene refererer til beregning av egenskaper for jets, disses bredder og partikkelutbytte per trigger. Geometrisk form og partikkelutbytte per trigger sammenlignes for proton-proton- og bly-bly-kollisjoner ved ulike sentraliteter, for å studere mediuminduserte jetmodifikasjoner IAA.
Main research findings / Hovedfunn
Jets are produced at the early stage of the collision, therefore they will be modified in the matter created during the interaction. Jet suppression in heavy-ion collisions with respect to proton-proton
collisions at the same energy, could be a sign of Quark Gluon Plasma (QGP) creation. The measure of suppression is defined through jet modification factors IAA .
Jet properties, obtained from charged hadron azimuthal two-particle correlations, per-trigger yields Yjet_ind and widths σ, have been investigated. The selected data are from the proton-proton collisions at √s = 2.76 TeV and √s = 7 TeV and lead-lead collisions at √sNN = 2.76 TeV and in the centrality range 0-30%.
The IAA modification pattern reported in this thesis, as well as other published works, is compatible with path-length dependent partonic energy loss in the hot QGP, leading to away-side suppression of
associated hadrons with transverse momenta pr > 3 - 4 GeV/c. The enhancement of low-pr associated hadrons observed both on the near- and away-side, indicate a transfer of the lost energy into soft particle production within and in the vicinity of the jet, more pronounced with increasing path length.