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Study of strange particle production in jets with the ALICE experiment at the LHC
Kučera, Vít ; Bielčíková, Jana (advisor) ; Dolejší, Jiří (referee) ; d´Enterria, David (referee)
Title: Study of strange particle production in jets with the ALICE experiment at the LHC Author: Vít Kučera Institute: Institute of Particle and Nuclear Physics Supervisors: RNDr. Jana Bielčíková, Ph.D., Nuclear Physics Institute of the CAS; Dr. Christian Kuhn, Institut Pluridisciplinaire Hubert CURIEN Abstract: Quark-gluon plasma is a state of matter existing under extreme energy densities and temperatures where quarks and gluons are deconfined. Complex phenomena occurring in the plasma emerge from the strong interaction of its constituents. This hot and dense strongly interacting matter can be created in ultra-relativistic heavy-ion collisions and its properties can be studied by measuring particles produced in the collisions. Partons produced in hard scatterings interact with the medium which modifies the production of particles in jets. Measurements of spectra of identified particles produced in jets represent an important tool for understanding the interplay of various hadronization mechanisms which contribute to the particle production in the medium created in heavy-ion collisions. In this thesis, we present the measurement of the pT spectra of Λ baryons and K0 S mesons produced in charged jets in central Pb-Pb collisions at the energy √ sNN = 2.76 TeV, measured in the ALICE experiment at the LHC. The...
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Produkce jetů s velkou příčnou hybností na LHC
Podškubka, Radek ; Kupčo, Alexander (advisor) ; Lysák, Roman (referee)
In the first part of the thesis, theoretical uncertainties of jet cross-section have been calculated for proton-proton collision at the center of mass energy of 8 TeV. For jet identification the anti-kT algorithm with scale parameter R = 0.6 was used. As the calculations showed, the major contribution to the total theoretical uncertainty comes from the uncertainty of parton distribution function parameters. In the second part of the thesis, the angular distribution of dijet events produced in proton-proton collisions at the center of mass energy 8 TeV were simulated using Pythia 8 Monte Carlo event generator. New physics model of quark compositeness that should manifest itself by quark contact interaction was studied using angular distribution of dijet events. Three angular variables were discussed and these variables were used to calculate 95% CL lower limit on contact interaction scale. The results were compared and it emerged that the sensitivity to contact interaction signals varies for these variables.
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Partonic showers and jets
Hladík, Ondřej ; Kupčo, Alexander (advisor) ; Spousta, Martin (referee)
Title: Partonic showers and jets Author: Ondřej Hladík Department: Institute of Theoretical Physics MFF UK Supervisor: Mgr. Alexander Kupčo, Ph.D., Institute of Physics ASCR, v. v. i. Abstract: In the present thesis we compare experimentally measured differential and integrated jets shapes with predictions of quantum chromodynamics (QCD) at the second order (NLO) of perturbative expansion. The measured jet sha- pes were taken from ATLAS experiment at LHC in proton-proton collisions at a center-of-mass energy √ s = 7 TeV and were compared with these predictions. The jets were reconstructed by means of anti-kT jet algorithm with R = 0.6. The predictions at NLO QCD agree with data in wider kinematics region than predictions at leading order (LO). The agreement, however, is still in some kine- matical regions not satisfactory. Keywords: QCD, jets, jet shapes, LHC
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Studium produkce jetů v jádro-jaderných srážkách na urychlovači RHIC
Barnovská, Zuzana ; Bielčíková, Jana (advisor) ; Tomášik, Boris (referee)
Title: Study of jet production in nucleus-nucleus collisions at RHIC Author: Mgr. Zuzana Barnovská Department: Institute of Particle and Nuclear Physics Supervisor: RNDr. Jana Bielčíková, Ph.D., Nuclear Physics Institute of the ASCR Abstract: The goal of this thesis is to study strange particles (Λ, ¯Λ a K0 S) in jets at the energy of √ sNN = 200 GeV in d+Au and Au+Au collisions measured by the STAR experiment at RHIC in 2007 and 2008. After the application of geometrical and topological limits, jets were reconstructed with the kT and anti- kT jet algorithms and special selection criteria for strange particles were applied. Ratios of the production of strange baryons and mesons in jets were calculated and compared to previous results of inclusive V0 particle production measured by the STAR experiment. Study of centrality dependence of these ratios was performed and compared to values in d+Au collisions. Keywords: jets, d+Au collisions, Au+Au collisions, STAR, RHIC 1
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Studium produkce jetů v experimentu ALICE na urychlovači LHC
Kučera, Vít ; Bielčíková, Jana (advisor) ; Dolejší, Jiří (referee)
Title: Study of jet production with the ALICE experiment at the LHC Author: Vít Kučera Department: Institute of Particle and Nuclear Physics Supervisor: RNDr. Jana Bielčíková, Ph.D., Nuclear Physics Institute of the ASCR, v.v.i. Abstract: The theory of strong interaction, quantum chromodynamics, predicts a phase transition between hadronic matter and the quark-gluon plasma where quarks and gluons are deconfined. This state of matter is expected to be created in ultra-relativistic collisions of heavy ions. Jets from partons which interact with the strongly interacting matter created in heavy-ion collisions can be used as probes to study this medium. The ALICE experiment installed at the Large Hadron Collider at CERN enables using jets to study medium in heavy-ion collisions. An analysis of data measured with the ALICE experiment in 2010 in the lead nuclei collisions at energy √ sNN = 2.76 TeV is presented in the thesis. The results of this analysis are presented in a study of jets reconstructed with the kt and anti-kt algorithms. The study includes an analysis of tracks, an analysis of background and focuses on an analysis of inclusive jet spectra. Various aspects of jet spectra are studied including modification of jets in the central collisions expressed by the ratio RCP. Also a summary of author's...
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A computational study on the effects of active flow control to the evolution of the wingtip vortices of a three dimensional wing
Skarolek, Vilém ; Hradil, Jiří (referee) ; Karampelas, Stavros (advisor)
V této diplomové práci byla provedena série numerických výpočtů proudění kolem křídla s aktivním řízením proudu. Výpočty jsou provedeny pro různé úhly náběhu křídla s profilem NACA 0015. Křídlo s zařízením pro aktivní řízení proudu bylo testováno v podmínkách s Machovým číslem M=0,21 a Re= 2500000. Bylo zkoušeno více možných konfigurací s cílem nalézt nejúčinější variantu, která bude zároveň stále energeticky efektivní. Vybraný přístup k aplikaci aktivního řízení na křídle se od ostatních liší. Použito je velkých ploch pro vyfukování vzduchu o nízké rychlosti a zároveň v souvislosti s tím je studována energetická účinnost. Snížení odporu a zvýšení vztlaku je dosaženo změnou řídících veličin. Při určitých specifických podmínkách je zařízení schopno při velmi vysoké energetické účinnosti dosáhnout pro všechny úhly náběhu výrazného snížení odporu, zvýšení vztlaku křídla, nebo obojího zároveň. Maximální pokles odporu křídla na malých úhlech náběhu přesahuje 40% z celkového odporu křídla a stále s dodržením energetické účinnosti.
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