Electron-D0 Correlations With ALICE In pp Collisions At LHC Energy

• Main Author: Altinpinar, Sedat
• Format: Others
• Language: English; en
• Published: 2012
• Online Access: https://tuprints.ulb.tu-darmstadt.de/3140/7/DissPublishPrint.pdf; Altinpinar, Sedat <http://tuprints.ulb.tu-darmstadt.de/view/person/Altinpinar=3ASedat=3A=3A.html> (2012): Electron-D0 Correlations With ALICE In pp Collisions At LHC Energy.Darmstadt, Technische Universität, [Ph.D. Thesis]

With ALICE at LHC a new energy domain of Quark-Gluon Plasma physics can be explored. Partonic energy loss studies are one of the major investigation methods, which can reveal important information about the interaction of quarks and gluons in the mentioned state of matter. To employ heavy quarks as probes is especially suited for this purpose, since they are created early in nucleus-nucleus collisions and experience the full collision history. An additional distinction between charm or bottom quarks contributes to refine the understanding of partonic energy loss. For this aim a separation method called factorization is developed. This analysis is based on the angular correlation of electrons from heavy-flavor hadron decays and D0 mesons, depending on the topology of underlying QCD processes. The purpose is to obtain a momentum dependent charm to beauty cross section ratio in proton-proton collisions, which is a baseline for the lead-lead collisions and an essential input for partonic energy loss models. The analysis presented is a groundwork, showing how such an analysis can be done in ALICE. Precondition of such kind of analysis are the reconstruction of D0 mesons and the identification and selection of electrons from heavy-flavor hadron decays. First D0 mesons in ALICE are measured, by developing a particle identification strategy for the D0 → Kπ decay mode and kinematical selection criteria for the mentioned two daughter particles. Moreover the measured D0 mesons provide the possibility to make comparisons with perturbative QCD cross section calculations and check their agreement. Conclusions on the statistical model are possible as well, with the measurement of the ratio of neutral and charged D mesons. Also a preliminary selection strategy to separate electrons from heavy-flavor hadron decays from other electrons is worked out and a novel background subtraction technique of non- heavy flavor background in the correlation distribution is presented as well. Since this analysis is very statistics-hungry, there is currently no statistically conclusive correlation plot possible, with the present amount of collected events. Nevertheless, a first evaluation employing the factorization method is done.