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Elastic proton-proton collisions at high energies
Procházka, Jiří ; Kundrát, Vojtěch (advisor) ; Osterberg, Kenneth (referee) ; Nemčík, Ján (referee)
Under the influence of standardly used (however, very simplified) description of Coulomb-hadronic interference proposed by West and Yennie (1968) the protons have been interpreted as "transparent" objects; elastic collisions have been interpreted as more central than inelastic ones. This property may be hardly put in agreement with the fact that in the majority of hadronic collisions many different particles have been created at high energies. Using the more general eikonal model it will be shown that the protons may be interpreted in agreement with usual conception; elastic processes being more peripheral than inelastic ones. The contemporary TOTEM experiment at the LHC accelerator in CERN devoted to measurement of elastic pp scattering and diffractive processes at the highest ever reached energies will be described. The eikonal model will be explained to greater details, generalized and applied to experimental data of elastic pp collisions under different assumptions at 52.8 GeV (older ISR data measured at CERN) and also at much higher energy of 8 TeV (new TOTEM data). The impact of different assumptions on determination of several quantities specifying hadron interaction will be studied. Mainly the assumptions influencing behaviour of elastic collisions in dependence on impact parameter of colliding...
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Study of charmonia production in proton-proton and heavy-ion collisions at the LHC
Krivoš, Martin ; Spousta, Martin (advisor) ; Řezníček, Pavel (referee)
In this thesis a production of J/ψ meson in pp and heavy-ion collisions was investigated. A comparison between Monte Carlo generator and data by ATLAS experiment at CERN was done. PYTHIA version 8.2 was chosen for the Monte Carlo generator. In the first part, comparisons of several configurations of PYTHIA were used to establish the best matching of the Monte Carlo to the data using collisions with centre-of-mass energy of 7 TeV. Choice of parton distribution functions was found not to be important, while presence or absence of initial and final state radiation were proven to have an important impact on the result. In the second part, correlation of J/ψ meson and the jet production was quantified. Anti-kt algorithm with R = 0.4 was used to reconstruct jets. Pairs of muons were used to identify J/ψ meson candidates. Only less than 10% of J/ψ mesons were found to be associated with jets. 1
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Elastic proton-proton collisions at high energies
Procházka, Jiří ; Kundrát, Vojtěch (advisor) ; Sýkora, Tomáš (referee) ; Dubnička, Stanislav (referee)
The proton, one of the basic constituents of atoms, was discovered around 1920. Its structure has been intensively studied since that time mainly with the help of proton- proton collision experiments. Main progress has started when corresponding experiments at the world's first hadron collider ISR at CERN which ran from 1971 to 1984 were performed. The understanding of the structure and interactions of this subatomic particle protons has been, however, rather incomplete. Only some very general models have been available especially in the case of higher collision energies when very different kinds of collisions have existed. Some very simplifying assumptions of unclear physical meaning have been then involved in models concerning elastic processes. The influence of these assumptions on physical interpretation has started to be studied and some progress has been made when the eikonal model has been proposed, i.e., the dependence of elastic collisions on corresponding impact parameter values has been taken into account from the beginning. However, even if some new results have been obtained many unanswered questions have remained. For example, the collision process has been denoted generally as probabilistic but corresponding probabilities have not been sufficiently defined and determined. The given thesis contains,...
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