Thèses sur le sujet « Hadronic jet »
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Kallweit, Stefan. « Precision calculations for Gauge-Boson pair production with a hadronic jet at Hadron colliders ». Diss., kostenfrei, 2008. http://edoc.ub.uni-muenchen.de/9362/.
Texte intégralFong, Che Ping. « Jet fragmentation at small momentum fractions in quantum chromodynamics ». Thesis, University of Cambridge, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.239209.
Texte intégralNewton, Warrick Miles. « Measurement of the inclusive one-jet and two-jet cross-sections in two-photon interactions at #sq root#=91 GeV ». Thesis, University of Sheffield, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.267065.
Texte intégralTsang, Wai Yeung. « Hadronic jet production at the CERN UA2 detector : an experimental test of QCD ». Thesis, University of Cambridge, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.254216.
Texte intégralChen, Xuan. « Hadronic production of a Higgs Boson in association with a jet at next-to-next-to-leading order ». Thesis, Durham University, 2015. http://etheses.dur.ac.uk/11158/.
Texte intégralWinter, Jan-Christopher. « QCD jet evolution at high and low scales ». Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2008. http://nbn-resolving.de/urn:nbn:de:bsz:14-ds-1208912443778-27732.
Texte intégralGupta, Shaun. « A study of longitudinal Hadronic shower leakage and the development of a correction for its associated effects at √s = 8 TeV with the ATLAS detector ». Thesis, University of Oxford, 2015. https://ora.ox.ac.uk/objects/uuid:3f37bd18-d4d2-40c5-b231-e193060ec218.
Texte intégralWinter, Jan-Christopher. « QCD jet evolution at high and low scales ». Doctoral thesis, Technische Universität Dresden, 2007. https://tud.qucosa.de/id/qucosa%3A23602.
Texte intégralBravo, Gallart Sílvia. « Measurements of the Strong Coupling Constant and the QCD Colour Factors using Four-Jet Observables from Hadronic Z Decays in Aleph ». Doctoral thesis, Universitat Autònoma de Barcelona, 2001. http://hdl.handle.net/10803/3335.
Texte intégralPer a les dues mesures s´usaren obervables de quatre jets. La mesura de la constant d´acoblament forta a partir de la taxa de sucesos a quatre jets fou la primera realitzada a partir d´un observable de quatre jet i en resultà una de les mesures més precises fins avui.
La mesura conjunta de la constant d´acoblament i els factors de color representa un prova rigorosa de la teoria de les interaccions fortes, la cromodinàmica quántica. Els resultats, amb incerteses molt competitives, estan en acord absolut amb els valors esperats per la teoria i també amb els resultats d'altres col·laboracions.
In this work two measurements are presented. One is the measurement of the strong coupling constant alone, and the other the combined measurement of the strong coupling constant and the, so called, colour factors. Data were collected by the ALEPH detector during years 1994-95 at energies around 91.2 GeV.
Both measurements made use of four-jet observables. The measurement of the strong coupling constant from the four-jet rate was the first ever made from a four-jet observable, and represents one of the most precise measurements at present.
The combined measurement of the strong coupling constant and the colour factors is a stringent test of the theory, quantum chromodynamics. The results, with very competitive uncertainties, are in exact agreement both with the values expected by the theory and the results from other collaborations.
Grahn, Karl-Johan. « Measurement of Multi-Jet Production in Proton-Proton Collisions at 7 TeV Center-of-Mass Energy and Hadronic Calibration Studies with the ATLAS Detector at CERN ». Doctoral thesis, KTH, Partikel- och astropartikelfysik, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-29111.
Texte intégralQC 20110125
Jammes, Jérôme. « Mesure de la section efficace de production de paires de quarks top dans le canal comportant un muon, un tau, des jets dont au moins un jet de b, et de l'énergie manquante auprès de l'expérience Dzero du Tevatron ». Phd thesis, Université Blaise Pascal - Clermont-Ferrand II, 2011. http://tel.archives-ouvertes.fr/tel-00840859.
Texte intégralFletcher, Gregory. « A Measurement of W+jets Z+jets with the ATLAS Detector ». Thesis, Queen Mary, University of London, 2015. http://qmro.qmul.ac.uk/xmlui/handle/123456789/8047.
Texte intégralHayward, Scott Kelly. « A study of the retention of quark quantum numbers in hadron jets ». Thesis, University of British Columbia, 1990. http://hdl.handle.net/2429/28775.
Texte intégralScience, Faculty of
Physics and Astronomy, Department of
Graduate
Williams, Peter Howard. « Hadronic Higgs production with forward jets ». Thesis, Durham University, 2003. http://etheses.dur.ac.uk/3131/.
Texte intégralJouttenus, Teppo T. (Teppo Tapani). « Jet production at hadron colliders ». Thesis, Massachusetts Institute of Technology, 2012. http://hdl.handle.net/1721.1/76979.
Texte intégralCataloged from PDF version of thesis.
Includes bibliographical references (p. 101-104).
Hadronic jets feature in many final states of interest in modern collider experiments. They form a significant Standard Model background for many proposed new physics processes and also probe QCD interactions at several different scales. At high energies incoming protons produce beam jets. Correctly accounting for the beam and central jets is critical to precise understanding of hadronic final states at the Large Hadron Collider. We study jet cross sections as a function of the shape of both beam and central jets. This work focuses on measuring jet mass but our methods can be applied to other jet shape variables as well. Measuring jet mass introduces additional scales to the collision process and these scales produce large logarithms that need to be resummed. Factorizing the cross section into hard, jet, beam, and soft functions enables such resummation. We begin by studying jet production at e + e- collisions in order to focus on the effects of jet algorithms. These results can be carried over to the more complicated case of hadron collisions. We use the Sterman-Weinberg algorithm as a specific example and derive an expression for the quark jet function. Turning to hadron colliders, we show how the N-jettiness event shape divides phase space into N +2 regions, each containing one central or beam jet. Thus, N-jettiness works as a jet algorithm. Using a geometric measure gives central jets with circular boundaries. We then give a factorization theorem for the cross section fully differential in the mass of each jet, and compute the corresponding soft function at next-to-leading order (NLO). We use a method of hemisphere decomposition, which can also be applied to calculate N-jet soft functions defined with other jet algorithms. Our calculation of the N-jettiness soft function provides the final missing ingredient to extend NLO cross sections to resunmmed predictions at next-to-next-to-leading logarithmic order. We study the production of an exclusive jet together with a Standard Model Higgs boson. Based on theoretical reasons and agreement between our calculation and data from the ATLAS collaboration, we argue that our results for the jet mass spectrum are a good approximation also for inclusive jet production and other hard processes.
by Teppo T. Jouttenus.
Ph.D.
Martini, Till. « The Matrix Element Method at next-to-leading order QCD using the example of single top-quark production at the LHC ». Doctoral thesis, Humboldt-Universität zu Berlin, 2018. http://dx.doi.org/10.18452/19288.
Texte intégralAnalyses in high energy physics aim to put the Standard Model—the commonly accepted theory—to test. For convincing conclusions, analysis methods are needed which offer an unambiguous comparison between data and theory while allowing reliable estimates of uncertainties. The Matrix Element Method (MEM) is a Maximum Likelihood method which is especially tailored for signal searches and parameter estimation at colliders. The MEM has proven to be beneficial due to optimal use of the available information and a clean statistical interpretation of the results. But it has a big drawback: In its original formulation, the likelihood calculation is intrinsically limited to the leading perturbative order in the coupling. Higher-order corrections improve the accuracy of theoretical predictions and allow for unambiguous field-theoretical interpretation of the extracted information. In this work, the MEM incorporating corrections of next-to-leading order (NLO) in QCD by defining event weights suited for the likelihood calculation is presented for the first time. These weights also enable the generation of unweighted events following the cross section calculated at NLO accuracy. The method is demonstrated for top-quark events. The top-quark mass is determined with the MEM at NLO accuracy from the generated events. The extracted estimators are in agreement with the input values from the event generation. Repeating the mass determinations from the same events, without NLO corrections in the predictions, results in biased estimators. These shifts may not be accounted for by estimated theoretical uncertainties rendering the estimation of the theoretical uncertainties unreliable in the leading-order analysis. The results emphasise the importance of the inclusion of NLO corrections into the MEM.
Hammad, Grégory. « Data-driven multi-jet and V+jets background estimation methods for top quark pair production at CMS ». Doctoral thesis, Universite Libre de Bruxelles, 2011. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/209884.
Texte intégralDoctorat en Sciences
info:eu-repo/semantics/nonPublished
Tripathee, Aashish. « Jet substructure at the Large Hadron Collider ». Thesis, Massachusetts Institute of Technology, 2010. http://hdl.handle.net/1721.1/111882.
Texte intégralCataloged from PDF version of thesis.
Includes bibliographical references (pages 57-60).
In this thesis, we use the CMS Open Data to study the 2-prong substructure of jets. We use CMS's particle flow reconstruction algorithm to obtain jet constituents, which we then use to perform various jet substructure studies. After validating our basic kinematics and substructure results through a comparison to results from parton shower generators, we extract the 2-prong substructure of the leading jet using the soft drop algorithm. We find good agreement between the results from the Open Data and those obtained from parton shower generators. For the 2-prong substructure, we also compare to analytic calculations performed to modified leading-logarithmic accuracy. To our best knowledge, this is the first ever physics analysis based on the CMS Open Data.
by Aashish Tripathee.
S.B.
Tripathee, Aashish. « Jet substructure at the Large Hadron Collider ». Thesis, Massachusetts Institute of Technology, 2017. http://hdl.handle.net/1721.1/111882.
Texte intégralCataloged from PDF version of thesis.
Includes bibliographical references (pages 57-60).
In this thesis, we use the CMS Open Data to study the 2-prong substructure of jets. We use CMS's particle flow reconstruction algorithm to obtain jet constituents, which we then use to perform various jet substructure studies. After validating our basic kinematics and substructure results through a comparison to results from parton shower generators, we extract the 2-prong substructure of the leading jet using the soft drop algorithm. We find good agreement between the results from the Open Data and those obtained from parton shower generators. For the 2-prong substructure, we also compare to analytic calculations performed to modified leading-logarithmic accuracy. To our best knowledge, this is the first ever physics analysis based on the CMS Open Data.
by Aashish Tripathee.
S.B.
Mao, Yaxian. « Mesure des corrélations gamma-hadrons et hadrons-hadrons dans les collisions pp à 7 TeV pour l'étude de la fragmentation des jets avec l'expérience ALICE du LHC ». Phd thesis, Université de Grenoble, 2011. http://tel.archives-ouvertes.fr/tel-00622562.
Texte intégralDoglioni, Caterina. « Measurement of the inclusive jet cross section with the ATLAS detector at the Large Hadron Collider ». Thesis, University of Oxford, 2012. http://doi.org/10.1007/978-3-642-30538-2.
Texte intégralValéry, Loïc. « Recherche de sgluons dans des états finals multitops avec le détecteur ATLAS auprès du LHC à √s = 8 TeV ». Thesis, Clermont-Ferrand 2, 2014. http://www.theses.fr/2014CLF22470/document.
Texte intégralDespite its experimental confirmations, the Standard Model, which describes both the elementary particles and three of the fundamental interactions, has some theoretical and experimental limitations. As a consequence of these limitations, a Physics not described in the context of the Standard Model could exist : the New Physics. This work focuses on the search for scalar gluons, commonly dubbed sgluons, predicted in various New Physics theories. A phenomenological study considers various final states (containing between two and four top quarks) and signatures (with one or two charged leptons) that could arise from sgluon production. The sensitivity of an Atlas-like experiment to this signal is estimated and the results indicate that one of the most promising final states contains four top quarks in a signature with two charged leptons (electron or muon) of the same electric charge. The search for sgluons within the Atlas experiment uses the previous results. Thus, it only investigates the 4-top topology in a signature containing two same-sign charged leptons, b-jets and missing transverse energy. It represents the first search ever for sgluons in this final state. The main steps of the analysis (background estimation, selection optimisation and statistical interpretation) are detailed. The comparison with the data recorded in the first months of 2012 (L = 14:3 fb..1) shows no significant excess and is interpreted in terms of a limit on the sgluon mass. The latter is found to be 0.80+0:02..0:03 TeV. The extension of this analysis to the full 2012 Atlas dataset is also presented in this document and shows an increased expected sensitivity to sgluon masses up to 0:94 0:03 TeV. Finally, this document also presents the analyses and results of performance studies. The first one is related to the high voltage system of the Atlas Tile Calorimeter (TileCal). The main conclusion is that only 7 channels out of the 9852 TileCal ones are fond to be problematic. The second study focuses on the rejection of the pile-up effect by the means of a selection applied on the so-called JVF (Jet Vertex Fraction) variable. The efficiency of this selection is computed both in data and simulation and shows some differences that have to be corrected in the simulation. The derivation of the correction factors and their associated systematic uncertainties is detailed in this document
Fiascaris, Maria. « W Boson production in association with hadronic jets at ATLAS ». Thesis, University of Oxford, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.543477.
Texte intégralCrispin, Ortuzar Mireia. « High jet multiplicity physics at the Large Hadron Collider ». Thesis, University of Oxford, 2015. http://ora.ox.ac.uk/objects/uuid:68af3867-1488-48d1-9738-73397ba3399d.
Texte intégralDreyer, Frédéric. « Precision physics at the large hadron collider ». Thesis, Paris 6, 2016. http://www.theses.fr/2016PA066170/document.
Texte intégralWith the advent of the LHC, particle physics has entered an era where high precision is required. In this thesis, we tackle two of the key processes at hadron colliders using innovative tools: inclusive jet production and Higgs production through vector-boson fusion (VBF). In the first part of this thesis, we show how to resum leading logarithmic terms of the jet radius R, and apply this formalism to a detailed study of the inclusive jet spectrum. We study subleading R-dependent terms at next-to-next-to-leading order (NNLO), and incorporate them into our calculation. We investigate cancellations in the scale dependence, leading to new prescriptions for evaluating uncertainties, and examine the impact of non-perturbative effects. In the second part of the thesis, we study QCD corrections in VBF-induced Higgs production. Using the structure function approach, we compute the next-to-next-to-next-to-leading order (NNNLO) corrections to the inclusive cross section. We then calculate the fully differential NNLO corrections to VBF Higgs production. We show that these contributions are substantial after VBF cuts, lying outside the NLO scale uncertainty bands
Pozo, Luis Andres del. « Tests of QCD from jet and hadron production at LEP ». Thesis, University of Cambridge, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.320401.
Texte intégralKhelifa, Kerfa Kamel. « QCD resummation for high-pT jet shapes at hadron colliders ». Thesis, University of Manchester, 2012. https://www.research.manchester.ac.uk/portal/en/theses/qcd-resummation-for-highpt-jet-shapes-at-hadron-colliders(16fdf645-238d-4979-8239-155f9ba07001).html.
Texte intégralBrooks, Helen Marguerite. « Multi-jet phenomenology for hadron colliders in the high energy limit ». Thesis, Durham University, 2017. http://etheses.dur.ac.uk/12313/.
Texte intégralHarman, Cates Michael Cates-Harman. « p0-Hadron Jet Correlations in He + Au Collisions at 200 GeV ». Ohio University Art and Sciences Honors Theses / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=ouashonors1462295771.
Texte intégralCockburn, James David. « Subleading corrections to hadronic cross-sections at high energies ». Thesis, University of Edinburgh, 2017. http://hdl.handle.net/1842/29519.
Texte intégralOhlson, Alice Elisabeth. « Investigating Parton Energy Loss in the Quark-Gluon Plasma with Jet-hadron Correlations and Jet Azimuthal Anisotrophy at STAR ». Thesis, Yale University, 2014. http://pqdtopen.proquest.com/#viewpdf?dispub=3578426.
Texte intégralIn high-energy collisions of gold nuclei at the Relativistic Heavy Ion Collider (RHIC) and of lead nuclei at the Large Hadron Collider (LHC), a new state of matter known as the Quark-Gluon Plasma (QGP) is formed. This strongly-coupled, deconfined state of quarks and gluons represents the high energy-density limit of quantum chromodynamics. The QGP can be probed by high-momentum quarks and gluons (collectively known as partons) that are produced in hard scatterings early in the collision. The partons traverse the QGP and fragment into collimated "jets" of hadrons. Studies of parton energy loss within the QGP, or medium-induced jet quenching, can lead to insights into the interactions between a colored probe (a parton) and the colored medium (the QGP).
Two analyses of jet quenching in relativistic heavy ion collisions are presented here. In the jet-hadron analysis, the distributions of charged hadrons with respect to the axis of a reconstructed jet are investigated as a function of azimuthal angle and transverse momentum (pT). It is shown that jets that traverse the QGP are softer (consisting of fewer high-pT fragments and more low-p T constituents) than jets in p+p collisions. There are also indications that the shapes of the distributions of charged hadrons about the jet axis are modified by interactions with the QGP. The results are quantitatively consistent with two models of medium-induced radiative parton energy loss.
A measurement of jet v2, defined as the correlation between reconstructed jets and the reaction plane or 2nd-harmonic participant plane (approximated by the 2nd-harmonic event plane), provides information about the medium-induced pathlength-dependence of parton energy loss. The event plane is reconstructed with detectors at forward pseudorapidity in order to reduce the artificial jet – event plane bias, which results from jet fragments being included in the event plane calculation. A non-zero jet v2 is measured, indicating that more jets are reconstructed with a higher energy in-plane compared to out-of-plane, which demonstrates that the parton energy loss depends on the length of the parton's path through the QGP.
The data analyzed here were collected in [special characters omitted] = 200 GeV Au+Au and p+p collisions at the STAR detector at RHIC. A novel method for measuring jet v2 is also proposed and tested in simulation.
DIltz, Christopher S. « Time Dependent Leptonic and Lepto-Hadronic Modeling of Blazar Emission ». Ohio University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1459506010.
Texte intégralCass, A. J. « A search for jets in direct photon events from hadronic collisions at 280GeV/c ». Thesis, University of Liverpool, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.234824.
Texte intégralSanguinetti, Grégory. « Calcul de la production d'une paire de bosons de jauge faible associée à un jet à l'approximation au-delà des logarithmes dominants ». Phd thesis, Chambéry, 2008. http://tel.archives-ouvertes.fr/tel-00331294.
Texte intégralBarter, William James. « Z boson and associated jet production at the LHCb experiment ». Thesis, University of Cambridge, 2014. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.707943.
Texte intégralScott, Patrick Aaron. « Search for medium effects with jet-like hadron correlations at ALICE at the LHC ». Thesis, University of Birmingham, 2013. http://etheses.bham.ac.uk//id/eprint/4542/.
Texte intégralAbeloos, Baptiste. « Recherche de particules supersymétriques dans le canal hadronique et calibration des jets avec le détecteur ATLAS du LHC ». Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLS200/document.
Texte intégralThe Standard Model of particle physics is a very precise model describing the elementary particles and their interactions. However, some issues lead physicists to search for physics beyond the Standard Model. Supersymmetry is an extension of the Standard Model providing solutions to the current issues. In this thesis, results are obtained using the data collected in 2015 and 2016 with the ATLAS detector at the LHC (CERN). The thesis is based in two parts:The first part is a performance analysis improving the energy measurement of high energy objects called "jets". They are generated by the hadronization of quarks and gluons in the detector via the strong nuclear interaction. My contribution is the last step of the the reconstruction and calibration chain and is fully based on data. The method uses the very precise measurement of the photon energy, and provides corrections to the jet energy scale. My contribution consists in set-up the method, estimate the corrections, measure the jet energy scale and evaluate the uncertainties. Corrections are at the order of 2-3% as a function of the jet energy scale. The uncertainty of the jet energy scale is estimated to be at the order of 1% for the three jet types. Results are now used by the ATLAS Collaboration. This method is also used to estimate the jet energy resolution. A resolution at the order of 17%-22% at 40 GeV depending on the jet type, and 4% at 1 TeV is obtained with an uncertainty at the order of 10%.The second part of the thesis corresponds to the search for supersymmetry. The signal corresponds to a pair of supersymmetric particles called squarks and gluinos and corresponds to jets and missing transverse energy in the final state. My contribution mainly corresponds to the optimisation of the selections using several simplified models of supersymmetry. Nine signal regions have been introduced in the analysis. Limits on the mass of squarks and gluinos computed during the Run 1 have been greatly improved to reach a maximal value respectively at the order of 1.6 TeV and 2 TeV
Williams, Ciaran. « Hadronic productions of a Higgs boson in association with two jets at next-to-leading order ». Thesis, Durham University, 2010. http://etheses.dur.ac.uk/414/.
Texte intégralCaucal, Paul. « Jet evolution in a dense QCD medium ». Thesis, université Paris-Saclay, 2020. http://www.theses.fr/2020UPASP002.
Texte intégralTo probe the properties of the quark-gluon plasma created in heavy-ion collisions, a very useful class of observables refers to the propagation of energetic jets. A jet is a collimated spray of particles generated via successive parton branchings, starting with a virtual quark or gluon produced by the collision. When such a jet is produced in the dense environment of a nucleus-nucleus collision, its interactions with the surrounding medium lead to a modification of its properties, phenomenon known as jet quenching. In this thesis, we develop a new theory to describe jet quenching. We compute for the first time the effects of the medium on multiple vacuum-like emissions, that is emissions triggered by the virtuality of the initial parton. We present a new physical picture for jet evolution, with notably a factorisation in time between vacuum-like emissions and medium-induced emissions. This picture is Markovian, hence well suited for a Monte Carlo implementation that we develop in the parton shower JetMed. We then investigate the phenomenological consequences of our new picture on jet observables and especially the jet nuclear modification factor RAA, the Soft Drop zg distribution and the jet fragmentation function. Our Monte Carlo results prove to be in good agreement with the LHC measurements
Wanotayaroj, Chaowaroj. « Search for a Scalar Partner of the Top Quark in the Jets+ETMiss Final State with the ATLAS detector ». Thesis, University of Oregon, 2017. http://hdl.handle.net/1794/22275.
Texte intégralLattaud, Hugues. « Photon et jets avec l'expérience CMS du LHC : de la calibration à la mesure ». Thesis, Lyon, 2019. http://www.theses.fr/2019LYSE1137/document.
Texte intégralThis PhD thesis presents two analysis using photon + jet events with the CMS experiment at the LHC. The first analysis presents the extraction of the jet energy calibration using the momentum balance between the jet and the photon in such events, the second analysis presents the photon + heavy flavored jet differential production cross section with proton proton collision at LHC
Hendricks, Khalida. « Jets + Missing Energy Signatures At The Large Hadron Collider ». The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1563367019906869.
Texte intégralHassan, Hadi. « Modélisation et mesure des facteurs de modification nucléaire des jets issus de quarks beaux dans les collisions p-Pb à 5.02 TeV avec l'expérience ALICE auprès du LHC ». Thesis, Université Grenoble Alpes (ComUE), 2019. http://www.theses.fr/2019GREAY008/document.
Texte intégralIn Pb-Pb collisions at the LHC, a hot and dense medium of deconfined quarks and gluons is formed, the so-called Quark-Gluon Plasma (QGP).The QGP is conjectured to be the state of matter of the early Universe up to few microseconds after the Big Bang and may still exist in the core of neutron stars. One of the most striking signatures of the QGP formation in heavy-ion collisions is the suppression of jet production. This phenomenon, called jet quenching, is ascribed to the energy lost by the initial parton while traveling through the QGP medium.In the last two decades, many theoretical developments of the theory of jet quenching have been formulated within pQCD.The main energy loss mechanisms proposed in the literature are attributed to radiative and collisional processes. Another kind of energy loss is developed in this work comprises a background field induced radiative energy loss which besides that besides scattering effects. Under the suggested model, a fast parton propagating through the medium will feel the effect of the color magnetic and the color electric fields while undergoing multiple scatterings with the particles in the medium.Besides, theoretical models predict that energy loss depends on the color charge and mass of the hard-scattered parton traversing the medium. Such mass dependence can be studied by measuring the production of hadrons and jets containing heavy-quarks in pp, p-Pb and Pb-Pb collisions at the LHC.In this thesis report, a new model for the medium is presented, which is described as a collection of static colored scattering centers in the presence of a chromomagnetic field, together with the description of the related energy loss mechanism. The ALICE measurement of b-jet production in pp and p-Pb collisions at $sqrt{s_{mathrm{NN}}}=5.02$ TeV using an impact parameter based tagger is also presented
Zhang, Fengwangdong. « Measurement of jet production in association with a Z boson at the LHC and jet energy correction calibration at high level trigger in CMS ». Doctoral thesis, Universite Libre de Bruxelles, 2017. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/251804.
Texte intégralCette thèse présente une mesure de la section efficace de production de jets associés à un boson Z dans les collisions proton-proton du Grand Collisionneur de Hadron (LHC) situé au CERN, avec des énergies dans le centre de masse de 8 TeV et 13 TeV, respectivement pour les années 2012 et 2015. Les données utilisées pour cette analyse ont été collectées par le détecteur Compact Muon Solenoid (CMS). Elles constituent des échantillons de luminosités intégrées de 19.6 fb⁻¹ et 2.25 fb⁻¹, respectivement pour 2012 et 2015. Nous mesurons la section efficace différentielle en fonction de la multiplicité de jets, de l’impulsion transverse et de la rapidité des jets, et en fonction de la somme scalaire des impulsions transverses des jets. La corrélation entre les rapidités du boson Z et des jets est aussi mesurée et bénéficie de la large statistique prise en 2012. Toutes les distributions d’observables mesurées sont obtenues après corrections pour les effets détecteurs et les résultats des canaux de désintégration muonique et électronique du boson Z sont combinés. Tenant compte des incertitudes statistiques et systématiques, les mesures sont comparées à différentes prédictions théoriques ayant différents niveaux de précision. Les prédictions sont obtenues de MADGRAPH 5, SHERPA 2 (pour l’analyse à 8 TeV uniquement), MADGRAPH_AMC@NLO, et un modèle fixé au NNLO (pour l’analyse à 13 TeV uniquement). Par ces mesures de précisions, et en particulier celle de la corrélation de rapidités, nous avons acquis une compréhension plus approfondie de la chromodynamique quantique dans son régime perturbatif. Grâce à la plus haute énergie jamais atteinte en laboratoire, et à la grande statistique disponible, nous avons sondé avec précision des endroits de l’espace des phases jusque là inaccessibles.Dans cette thèse, les corrections et la calibration de l’énergie des jets pour le haut niveau de sélection de CMS est également présentée. Durant la période de 2012 à 2015, le LHC a été amélioré, non seulement l’énergie dans le centre de masse a augmenté, mais la luminosité instantanée a aussi été amplifiée. L’écart temporelle entre deux paquets de particules dans les faisceaux du LHC a été réduite. L’une des conséquences est que l’impulsion reconstruite pour les jets produits lors d’un croisement de faisceau à une contribution significative venant des multiples interactions ayant lieux lors du croisement des paquets. Une approche technique dédiée a été développée pour corriger l'impulsion des jets. Les corrections obtenues ont été calibrées aux données prises en 2015 et 2016.
Doctorat en Sciences
info:eu-repo/semantics/nonPublished
Hill, P. V. « A model insensitive determination of the strong coupling constant and a measurement of the energy spread of quark jets in electron positron annihilation ». Thesis, University of Manchester, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.379148.
Texte intégralMahmoudi, Farvah. « Chromodynamique quantique aux collisionneurs hadroniques : vers une automatisation du calcul des processus multi-particules à l'ordre d'une boucle : application à la production de deux photons et un jet ». Chambéry, 2004. http://www.theses.fr/2004CHAMS013.
Texte intégralThe future CERN collider (LHC) bas a fantastic potential of discovery, provided QCD can be quantitatively predicted. To do so, it is necessary to work at NLO approximation in order to reduce the dependence of the cross-section on the non-physical scales. To obtain results in this approximation, one has to calculate the cross-sections of the partonic subprocesses contributing to the studied reaction at the lowest order, and also the virtual corrections (loop corrections) and the real corrections. The calculation of the virtual corrections remains very complicated if the number of external particles is greater than four or if the external (internal) particles are massive. Ln this thesis, an automatic method which enables to calculate one loop diagrams with five external legs and which can be generalized to the case of massive particles is presented. Ln a first part, we describe different tools and methods necessary to such calculations. We then apply them to the calculation of the (gluon + gluon -> photon + photon + gluon) reaction, which interests the ATLAS and CMS experimentalists as the background for the Higgs boson search. We also give the explicit result for this amplitude for each helicity configuration in a compact form and a clearly gauge invariant representation. We finally present a phenomenological study of this reaction
Klein, Jochen [Verfasser], et Johanna [Akademischer Betreuer] Stachel. « Jet Physics with A Large Ion Collider Experiment at the Large Hadron Collider / Jochen Klein ; Betreuer : Johanna Stachel ». Heidelberg : Universitätsbibliothek Heidelberg, 2014. http://d-nb.info/1180033094/34.
Texte intégralTiras, Emrah. « Characterization of 900 four-anode photomultiplier tubes for use in 2013 hadronic forward calorimeter upgrade ». Thesis, University of Iowa, 2012. https://ir.uiowa.edu/etd/3392.
Texte intégralRodrigues, Eduardo. « Azimuthal angle asymmetries of hadrons and jets in deep inelastic scattering at HERA ». Thesis, University of Bristol, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.247646.
Texte intégralBhauruth, Yaadav. « Beam density functions in van der Meer scans and leptonically decaying off-shell Z bosons in association with two hadronic jets ». Thesis, University of Manchester, 2018. https://www.research.manchester.ac.uk/portal/en/theses/beam-density-functions-in-van-der-meer-scans-and-leptonically-decaying-offshell-z-bosons-in-association-with-two-hadronic-jets(a81f2cb5-9235-4d6b-8b60-014a51884918).html.
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