763 research outputs found
Studium srážek protonů a těžkých iontů v experimentu ATLAS na LHC
No full textNázev práce: Studium srážek protonů a těžkých iontů v experimentu ATLAS na LHC Autor: Mgr. Petr Balek Katedra: Ústav částicové a jaderné fyziky Vedoucí disertační práce: Doc. RNDr. Jiří Dolejší, CSc. Abstrakt: Presentované výsledky jaderného modifikačního faktoru ukazují potla- čení produkce nabitých hadronů ve srážkách těžkých iontů v porovnání s produkcí v proton-protonových srážkách. Data použitá pro tuto práci byla nabrána de- tektorem ATLAS na LHC v letech 2010 a 2011 ve srážkách Pb+Pb o těžišťové energii √ sNN = 2.76 TeV a o celkové integrované luminositě 0.15 nb−1 . Proton- protonová data byla nabrána v letech 2011 a 2013 ve srážkách o těžišťové energii√ s = 2.76 TeV a mají celkovou integrovanou luminositu 4.2 nb−1 . Výsledky jsou presentovány v intervalech příčné hybnosti (0.5 < pT < 150 GeV) a pseudora- pidity (|η| < 2), a též v různých centralitách srážek těžkých iontů. Jaderný modifikační faktor RAA ukazuje jasnou závislost na pT s minimem okolo 7 GeV, avšak nad 60 GeV je téměř nezávislý na pT. Jakožto funkce |η| je RAA ploché v celém intervalu příčné hybnosti. Klíčová slova: detektor ATLAS, srážky těžkých iontů, spektra nabitých hadronů, jaderný modifikační faktor RAATitle: Study of proton-proton and heavy-ion collisions with the ATLAS experi- ment at the LHC Author: Mgr. Petr Balek Department: Institute of Particle and Nuclear Physics Supervisor: Doc. RNDr. Jiří Dolejší, CSc. Abstract: The presented results show a suppression in a production of charged hadrons in heavy-ion collisions with respect to the production measured in proton- proton collisions. Lead-lead data at √ sNN = 2.76 TeV were recorded by the AT- LAS experiment at the LHC in 2010 and 2011 and they have a total integrated luminosity of 0.15 nb−1 , and proton-proton data at √ s = 2.76 TeV were recorded in 2011 and 2013 having an integrated luminosity of 4.2 nb−1 . The results are presented in wide transverse momentum (0.5 < pT < 150 GeV) and pseudorapid- ity (|η| < 2) ranges, and also in different centrality intervals of Pb+Pb collisions. Nuclear modification factor RAA shows a clear pT-dependence with a minimum at around 7 GeV, however above 60 GeV, it reaches a plateau with no significant pT-dependence. As a function of |η|, the RAA is flat over whole pT region. Keywords: ATLAS detector, heavy-ion collisions, charged-hadron spectra, nuclear modification factor RAAÚstav částicové a jaderné fyzikyInstitute of Particle and Nuclear PhysicsMatematicko-fyzikální fakultaFaculty of Mathematics and Physic
Study of proton-proton and heavy-ion collisions with the ATLAS experiment at the LHC
No full textTitle: Study of proton-proton and heavy-ion collisions with the ATLAS experi- ment at the LHC Author: Mgr. Petr Balek Department: Institute of Particle and Nuclear Physics Supervisor: Doc. RNDr. Jiří Dolejší, CSc. Abstract: The presented results show a suppression in a production of charged hadrons in heavy-ion collisions with respect to the production measured in proton- proton collisions. Lead-lead data at √ sNN = 2.76 TeV were recorded by the AT- LAS experiment at the LHC in 2010 and 2011 and they have a total integrated luminosity of 0.15 nb−1 , and proton-proton data at √ s = 2.76 TeV were recorded in 2011 and 2013 having an integrated luminosity of 4.2 nb−1 . The results are presented in wide transverse momentum (0.5 < pT < 150 GeV) and pseudorapid- ity (|η| < 2) ranges, and also in different centrality intervals of Pb+Pb collisions. Nuclear modification factor RAA shows a clear pT-dependence with a minimum at around 7 GeV, however above 60 GeV, it reaches a plateau with no significant pT-dependence. As a function of |η|, the RAA is flat over whole pT region. Keywords: ATLAS detector, heavy-ion collisions, charged-hadron spectra, nuclear modification factor RA
Measurement of the nuclear modification factor for high- charged hadrons in p +Pb collisions with the ATLAS detector
No full textThe charged hadron spectra in p +Pb and pp collisions at sNN=s=5.02 TeV are measured with the ATLAS experiment at the LHC. The measurements are performed with p +Pb data recorded in 2013 with an integrated luminosity of 25 nb−1 and pp data recorded in 2015 with an integrated luminosity of 28 pb−1 . The p +Pb results are compared to pp spectra, presented as a ratio of transverse momentum distributions in the two systems scaled by the number of binary nucleon–nucleon collisions, the nuclear modification factor R p Pb . The study of R p Pb allows a detailed comparison of the collision systems in different centrality intervals and in a wide range of transverse momentum. It is shown that the nuclear modification factor does not have any significant deviation from unity in the high transverse momentum region.The charged hadron spectra in +Pb and collisions at TeV are measured with the ATLAS experiment at the LHC. The measurements are performed with +Pb data recorded in 2013 with an integrated luminosity of 25nb and data recorded in 2015 with an integrated luminosity of 28pb. The +Pb results are compared to spectra, presented as a ratio of transverse momentum distributions in the two systems scaled by the number of binary nucleon-nucleon collisions, the nuclear modification factor . The study of allows a detailed comparison of the collision systems in different centrality intervals and in a wide range of transverse momentum. It is shown that the nuclear modification factor does not have any significant deviation from unity in the high transverse momentum region
ATLAS highlights: Recent results from ATLAS
No full textThe ATLAS experiment at the Large Hadron Collider encompasses a wide-ranging physics program that includes various collision systems and center-of-mass energies. These proceedings provide an overview of the recent ATLAS measurements regarding heavy ion collisions, heavy flavour production, and collective behaviour. The data utilized in the presented results were recorded during LHC Run 2 (2015--2018). The measurements can help to understand various physics phenomena from hard scatterings to soft processes, and from large systems to small systems
Charged-particle production in Pb+Pb and Xe+Xe collisions measured with the ATLAS detector
No full textThe measurement of charge-particle production in heavy-ion collision systems and its comparison to data provide an insight into the properties of the quark-gluon plasma produced in collisions of heavy ions. In 2015, the ATLAS detector at the LHC recorded 0.49 nb of Pb+Pb collisions and 25 pb of collisions at the center-of-mass energy = 5.02 TeV. In addition, around 3 b of Xe+Xe collisions at = 5.44 TeV were recorder in 2017. These samples provide an opportunity to study the system size dependence of the parton energy loss. The large acceptance of the ATLAS detector allows measurements of charged-particle spectra in a wide range of both pseudorapidity and transverse momentum, differentially in collision centrality. The charged-particle spectra measured in Pb+Pb and Xe+Xe collisions are compared to the analogous spectra measured in collisions, and the resulting nuclear modification factors are scrutinized
Measurements of charged particle spectra and nuclear modification factors in p+Pb and Pb+Pb collisions with the ATLAS detector
No full textThe measurement of charged particle spectra in heavy ion collisions carries important information about the properties of hot and dense matter created in these interactions. Spectra measured in lead-lead collisions at different centralities can be compared to the proton-proton spectra giving quantitative information about the properties of such matter. Proton-nucleus collisions provide further means for understanding the role of the initial state effects modifying the hard scattering rates. The ATLAS detector at the LHC obtained the sample of Pb+Pb data at = 2.76 TeV with integrated luminosity 0.15 nb, which can be compared to recently obtained pp sample of 4.5 pb sample at the same energy. The p+Pb data at = 5.02 TeV with integrated luminosity 30 nb can also be compared to the pp data obtained by interpolating pp measurements at = 2.76 TeV and 7 TeV. Due to the excellent capabilities of the ATLAS detector, and its stable operation in heavy ion as well as proton-proton physics runs, the data allow measurements of the nuclear modification factor out to transverse momentum limited only by the statistics of the accumulated samples and studying the ratios of HI charged particle spectra divided by pp reference in different centrality bins over a wide range of pseudorapidity
Podnikatelský plán soukromého středoškolského školství
No full textPráce je zaměřena na vypracování podnikatelského plánu konkrétní soukromé školy. Práce popisuje a srovnává soukromé školy se státními, hledá konkurenční výhody pro oblast v tomto podnikání.Práce hodnotí management a organizaci školy,popisuje její okolí,zabývá se obory studia a formami,vzdělávacím procesem, ale i finančním plánem a hospodařením školy
Podnikatelský plán soukromého středoškolského školství
No full textPráce je zaměřena na vypracování podnikatelského plánu konkrétní soukromé školy. Práce popisuje a srovnává soukromé školy se státními, hledá konkurenční výhody pro oblast v tomto podnikání.Práce hodnotí management a organizaci školy,popisuje její okolí,zabývá se obory studia a formami,vzdělávacím procesem, ale i finančním plánem a hospodařením školy
Inhomogeneous cosmology and averaging methods
No full textIn this work we have examined different methods of averaging in general relativity and cosmology. We developed the method based on Cartan scalars. We computed the backreaction term for a flat LTB model with a special ansatz for the radial function. We found out that it behaves as a positive cosmological constant. In the next part of this thesis we were interested in averaging inside LRS class II dust model. For this family we averaged all the Einstein equations and the resulting system generalizes the Buchert equations. We numerically worked out two concrete examples where deceleration parameter changes its sign from positive to negative. Powered by TCPDF (www.tcpdf.org
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