1,979 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
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
Emanation thermal analysis study of a sol-gel precursor for silica-titania waveguides
No full textEmanation Thermal Analysis (ETA) was demonstrated as a tool for the characterization of microstructure
changes of a sol–gel precursor for silica–titania layers deposited on the glass plate to be
used as planar waveguides. Temperature ranges of 280–330 and 380–500°C, respectively, in which
the densification of the layers took place, were determined by ETA under in situ conditions of the
sample heating. Results of thermogravimetry were compared with the ETA data
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
Azimuthally-dependent femtoscopy in central p+Pb collisions at 5.02\,TeV with the ATLAS detector
No full textHanbury Brown and Twiss (HBT) radii with respect to the 2nd-order event plane are measured in central p+Pb collisions at TeV with the ATLAS detector at the LHC. A total integrated luminosity of 28 nb is sampled. The radii and their relative modulation are presented as a function of the magnitude of the flow vector |q_2| measured at the side of the calorimeters that the Pb beam faces with pseudorapidity η < −2.5. Modulations of the transverse HBT radii are observed with the same orientation as in ion-ion collisions, in which they are attributed to hydrodynamic evolution from an elliptic initial geometry. This modulation is consistent with a hydrodynamic evolution of a short-lived medium
Charged particle spectra and nuclear modification factor in lead-lead collisions at 2.76 TeV with the ATLAS detector at the LHC.
No full textThe measurement of charged particle spectra in heavy ion collisions is a direct way to study properties of hot and dense matter created in these interactions. The centrality dependence of the spectral shape is an important tool to understand the energy loss mechanism. The ATLAS detector at the LHC accumulated 150µb-1 of lead-lead data at 2.76 TeV per nucleon-nucleon pair. Due to the excellent capabilities of the ATLAS detector, and its stable operation in 2010 and 2011 heavy ion physics runs, these data allow measurements of the charged particle spectra and their ratios in different centrality bins over a wide range of transverse momenta and pseudorapidity
ATLAS Heavy Ion Results
No full textThe results from the lead-lead collisions at sqrt(s_NN)=2.76TeV measured by ATLAS detector at the LHC are presented. The ATLAS experiment is a general purpose detector with large acceptance in pseudorapidity and full coverage in azimuthal angle. The data collected in years 2010 and 2011 allow us to analyse properties of hot dense matter created in Pb+Pb collisions. Global event properties, the study of weak bosons production, jet properties and charged hadron production are presented
Expected effects of climate change on the soil organic matter content related to contrasting agricultural management practices based on a crop model ensemble for locations in Czechia
No full textFunder:
http://dx.doi.org/10.13039/501100006533
Ministerstvo ZemědělstvíFunder:
http://dx.doi.org/10.13039/100014809
Technology Agency of the Czech Republi
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