Top Antitop Cross Section Measurement As A Function Of The Jet Multiplicity In The Final State And Beyond The Standard Model Top Antitop Resonances Search At The Atlas Detector At Cern PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Top Antitop Cross Section Measurement As A Function Of The Jet Multiplicity In The Final State And Beyond The Standard Model Top Antitop Resonances Search At The Atlas Detector At Cern PDF full book. Access full book title Top Antitop Cross Section Measurement As A Function Of The Jet Multiplicity In The Final State And Beyond The Standard Model Top Antitop Resonances Search At The Atlas Detector At Cern.
Author | : Danilo Enoque Ferreira de Lima |
Publisher | : |
Total Pages | : 225 |
Release | : 2014 |
Genre | : Large Hadron Collider (France and Switzerland) |
ISBN | : |
Download Top-antitop Cross Section Measurement as a Function of the Jet Multiplicity in the Final State and Beyond the Standard Model Top-antitop Resonances Search at the ATLAS Detector at CERN Book in PDF, ePub and Kindle
Author | : |
Publisher | : |
Total Pages | : 39 |
Release | : 2011 |
Genre | : |
ISBN | : |
Download Measurement of the Top-antitop Production Cross Section in Pp Collisions at Sqrt(s) Book in PDF, ePub and Kindle
A measurement of the top-antitop production cross section in proton-proton collisions at a centre-of-mass energy of 7 TeV has been performed at the LHC with the CMS detector. The analysis uses a data sample corresponding to an integrated luminosity of 36 inverse picobarns and is based on the reconstruction of the final state with one isolated, high transverse-momentum electron or muon and three or more hadronic jets. The kinematic properties of the events are used to separate the top-antitop signal from W+jets and QCD multijet background events. The measured cross section is 173 + 39 - 32 (stat. + syst.) pb, consistent with standard model expectations.
Author | : DooKee Cho |
Publisher | : |
Total Pages | : 116 |
Release | : 2005 |
Genre | : |
ISBN | : |
Download Measurement of the Top - Anti-top Production Cross Section at S**(/1/2) Book in PDF, ePub and Kindle
We discuss the measurement of the cross section for t{bar t} production in p{bar p} collisions at {radical}s = 1.96 TeV in e+jets final states observed at the D0 experiment at the Fermilab Tevatron. Our result is based on data collected from the June 2002 to September 2003 period of Run II of the p{bar p} Collider. In the Standard Model, the top quark is expected to decay mainly into a W boson and a b quark. The W boson can decay subsequently into a lepton and its neutrino or a q{bar q} quark-antiquark pair. In this thesis, we focus on the e{sup +} {nu}{sub e} or e{sup -} {bar {nu}}{sub e} decays of one of the W bosons and the q{bar q} decays of the other W boson in t{bar t} final states. The b, q and q' quarks appear as jets of particles in the detector, thereby defining the e+jets final state. We present two methods used for performing this measurement. The first method is based on a Random Grid Search (RGS) that minimizes the uncertainty on the extracted cross section. The variables used in the search take advantage of differences between expected background and signal processes to obtain the yield of t{bar t} events. The second method uses a Neural Network (NN) procedure that discriminates signal from background through the application of a NN trained on simulated t{bar t} signal and W+jets background events. The preliminary results presented in this thesis for inclusive t{bar t} production are {sigma}{sub p{bar p} {yields} t{bar t} + x} of 7.9{sub -2.4}{sup +2.6}(stat) {sub -2.3}{sup +2.2}(syst) {+-} 0.5 (L) pb for the NN analysis, where the uncertainties correspond to contributions from statistical and systematic sources and from the uncertainty on luminosity. Our measurements are consistent with each other, and are within error of the value of 6.77 {+-} 0.42 pb expected in the Standard Model.
Author | : |
Publisher | : |
Total Pages | : 116 |
Release | : 2005 |
Genre | : |
ISBN | : |
Download Measurement of the Top - Anti-top Production Cross Section at {u221A}s Book in PDF, ePub and Kindle
We discuss the measurement of the cross section for t$ar{t}$ production in p$ar{p}$ collisions at √s = 1.96 TeV in e+jets final states observed at the D0 experiment at the Fermilab Tevatron. Our result is based on data collected from the June 2002 to September 2003 period of Run II of the p$ar{p}$ Collider. In the Standard Model, the top quark is expected to decay mainly into a W boson and a b quark. The W boson can decay subsequently into a lepton and its neutrino or a q$ar{q}$ quark-antiquark pair. In this thesis, we focus on the e+ ve or e- $ar{v}$e decays of one of the W bosons and the q$ar{q}$ decays of the other W boson in t$ar{t}$ final states. The b, q and q' quarks appear as jets of particles in the detector, thereby defining the e+jets final state. We present two methods used for performing this measurement. The first method is based on a Random Grid Search (RGS) that minimizes the uncertainty on the extracted cross section. The variables used in the search take advantage of differences between expected background and signal processes to obtain the yield of t$ar{t}$ events. The second method uses a Neural Network (NN) procedure that discriminates signal from background through the application of a NN trained on simulated t$ar{t}$ signal and W+jets background events. The preliminary results presented in this thesis for inclusive t$ar{t}$ production are ? p$ar{p}$ → t$ar{t}$ + x of 7.9$+2.6top{-2.4}$(stat) $+2.2top{-2.3}$(syst) ± 0.5 (L) pb for the NN analysis, where the uncertainties correspond to contributions from statistical and systematic sources and from the uncertainty on luminosity. Our measurements are consistent with each other, and are within error of the value of 6.77 ± 0.42 pb expected in the Standard Model.
Author | : Robert Hankache |
Publisher | : |
Total Pages | : 0 |
Release | : 2019 |
Genre | : |
ISBN | : |
Download Jet Calibration, Cross Section Measurements and New Physics Searches with the ATLAS Experiment Within the Run 2 Data Book in PDF, ePub and Kindle
The Standard Model is the current theory used to describe the elementary particles and their fundamental interactions (except the gravity). My PhD within the ATLAS experiment put this model under test using objects called jets, to study final state particles that interact through the strong force. First, I contributed to a method of jet calibration aiming at calibrating the energy scale of jets in the forward region of the detector with respect to central region. I improved the calibration by making it faster and more precise. Next, I worked on a search analysis of new physics using events with two jets. The Standard Model predicts a smooth distribution of the invariant mass of di-jets, hence we search for a bump which could come from a new particle. Since no significant bump is found, we put limits on signals as predicted by Beyond Standard Model theories and on model-independent signals. Last, I developed a new physics analysis measuring the leading (highest in transverse momentum) jet differential cross-section as a function of transverse momentum and rapidity. The challenge was to factorize the detector effects (resolution and acceptance) from the observable, which I did using a new unfolding technique. I also worked on the theoretical predictions calculation which was very challenging to perform and needed the implementation of special regularizations. The measurement and the predictions are then compared and tensions are observed due to the difficulties of theoretical predictions calculation.
Author | : Simone Marzani |
Publisher | : Springer |
Total Pages | : 205 |
Release | : 2019-05-11 |
Genre | : Science |
ISBN | : 3030157091 |
Download Looking Inside Jets Book in PDF, ePub and Kindle
This concise primer reviews the latest developments in the field of jets. Jets are collinear sprays of hadrons produced in very high-energy collisions, e.g. at the LHC or at a future hadron collider. They are essential to and ubiquitous in experimental analyses, making their study crucial. At present LHC energies and beyond, massive particles around the electroweak scale are frequently produced with transverse momenta that are much larger than their mass, i.e., boosted. The decay products of such boosted massive objects tend to occupy only a relatively small and confined area of the detector and are observed as a single jet. Jets hence arise from many different sources and it is important to be able to distinguish the rare events with boosted resonances from the large backgrounds originating from Quantum Chromodynamics (QCD). This requires familiarity with the internal properties of jets, such as their different radiation patterns, a field broadly known as jet substructure. This set of notes begins by providing a phenomenological motivation, explaining why the study of jets and their substructure is of particular importance for the current and future program of the LHC, followed by a brief but insightful introduction to QCD and to hadron-collider phenomenology. The next section introduces jets as complex objects constructed from a sequential recombination algorithm. In this context some experimental aspects are also reviewed. Since jet substructure calculations are multi-scale problems that call for all-order treatments (resummations), the bases of such calculations are discussed for simple jet quantities. With these QCD and jet physics ingredients in hand, readers can then dig into jet substructure itself. Accordingly, these notes first highlight the main concepts behind substructure techniques and introduce a list of the main jet substructure tools that have been used over the past decade. Analytic calculations are then provided for several families of tools, the goal being to identify their key characteristics. In closing, the book provides an overview of LHC searches and measurements where jet substructure techniques are used, reviews the main take-home messages, and outlines future perspectives.
Author | : Arnulf Quadt |
Publisher | : Springer Science & Business Media |
Total Pages | : 166 |
Release | : 2007-08-16 |
Genre | : Science |
ISBN | : 3540710604 |
Download Top Quark Physics at Hadron Colliders Book in PDF, ePub and Kindle
This will be a required acquisition text for academic libraries. More than ten years after its discovery, still relatively little is known about the top quark, the heaviest known elementary particle. This extensive survey summarizes and reviews top-quark physics based on the precision measurements at the Fermilab Tevatron Collider, as well as examining in detail the sensitivity of these experiments to new physics. Finally, the author provides an overview of top quark physics at the Large Hadron Collider.
Author | : John Campbell |
Publisher | : Oxford University Press |
Total Pages | : 760 |
Release | : 2018 |
Genre | : Science |
ISBN | : 0199652740 |
Download The Black Book of Quantum Chromodynamics Book in PDF, ePub and Kindle
This title provides an in-depth introduction to the particle physics of current and future experiments at particle accelerators. The text provides the reader with an overview of practically all aspects of the strong interaction necessary to understand and appreciate modern particle phenomenology at the energy frontier.
Author | : Joseph Francis Kozminski |
Publisher | : |
Total Pages | : 218 |
Release | : 2005 |
Genre | : |
ISBN | : |
Download Measurements of the Top - Anti-top Production Cross Section at S**(1/2) Book in PDF, ePub and Kindle
The first measurement of the top-antitop production cross section in proton-antiproton collisions at {radical}s = 1.96 TeV using 243 pb{sup -1} of data collected with the D0 detector at Fermilab is presented. In this analysis, only the dielectron final state is considered. Five events are observed, and 0.93 background events are expected. The measured cross section, after accounting for the expected branching ratio to the dielectron channel, is {sigma}{sub t{bar t}} = 14.9{sub -7.0}{sup +9.4}(stat){sub -1.8}{sup +2.5}(syst) {+-} 1.0 (lumi) pb, which agrees with the predicted cross section for top quarks with a mass of 175 GeV. In addition, a first-pass at a measurement of the top mass using the neutrino-weighting method is presented. This measurement is also performed in the dielectron channel using the five events observed in the cross section measurement.
Author | : Howard Baer |
Publisher | : Cambridge University Press |
Total Pages | : 557 |
Release | : 2023-01-31 |
Genre | : Science |
ISBN | : 1009289845 |
Download Weak Scale Supersymmetry Book in PDF, ePub and Kindle
This OA text develops the basic concepts of supersymmetry for experimental and phenomenological particle physicists and graduate students.