Disputation: Olja Dordic

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.

Ex auditorio questions: the chair of the defence will invite the audience to ask ex auditorio questions either written or oral. This can be requested by clicking 'Participants -> Raise hand'. 

Trial lecture 

Digital recording of the trial lecture

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 √s_NN

= 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 I_AA.


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 I_AA .
Jet properties, obtained from charged hadron azimuthal two-particle correlations, per-trigger yields Y_{jet_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 √

s_NN = 2.76 TeV and in the centrality range 0-30%.
The I_AA 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 p_r > 3 - 4 GeV/c. The enhancement of low-p_r 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.