D-meson production by muons in the COMPASS experiment at CERN [Elektronische Ressource] / vorgelegt von Alexander Zvyagin

D-meson production by muons in theCOMPASS experiment at CERNAlexander ZvyaginMunchen, November 2010D-meson production by muons in theCOMPASS experiment at CERNAlexander ZvyaginDissertationan der Fakult at fur Physikder Ludwig{Maximilians{Universit atMunc henvorgelegt vonAlexander Zvyaginaus Moskau, RusslandMunc hen, November 2010Erstgutachter: Prof. Dr. Martin FaesslerZweitgutachter: Prof. Dr. Dorothee SchaileTag der mundlic hen Prufung: 21 Januar 2011vAbstractOne of the physics goals of the COMPASS experiment at CERN was to measure thecontribution of gluons to the nucleon spin. To achieve this, it was proposed to scatterpolarized 160 GeV=c muons on a polarized deuteron target and to detect D mesons inthe nal state. The underlying process in this D meson production is supposed to be thePhoton-Gluon Fusion (PGF), where a virtual photon emitted by the muon interacts with agluon from the target nucleon, producing a charm-anticharm quark pair. Fragmentation of0 a charm (anticharm) quark leads with high probability to the creation of aD orD meson,0 0which COMPASS detects via the D !K and D !D !K decay modes. Fromthe longitudinal cross section spin asymmetries of theD meson production and theoreticalpredictions for the PGF cross section, the gluon contribution to the nucleon spin has beenmeasured by the COMPASS experiment.The results presented in the thesis are the following.