Top Quark Pair Production
Title | Top Quark Pair Production PDF eBook |
Author | Anna Christine Henrichs |
Publisher | Springer Science & Business Media |
Pages | 231 |
Release | 2013-10-04 |
Genre | Science |
ISBN | 3319014870 |
Before any kind of new physics discovery could be made at the LHC, a precise understanding and measurement of the Standard Model of particle physics' processes was necessary. The book provides an introduction to top quark production in the context of the Standard Model and presents two such precise measurements of the production of top quark pairs in proton-proton collisions at a center-of-mass energy of 7 TeV that were observed with the ATLAS Experiment at the LHC. The presented measurements focus on events with one charged lepton, missing transverse energy and jets. Using novel and advanced analysis techniques as well as a good understanding of the detector, they constitute the most precise measurements of the quantity at that time.
Top-Quark Pair Production Cross Sections and Calibration of the Top-Quark Monte-Carlo Mass
Title | Top-Quark Pair Production Cross Sections and Calibration of the Top-Quark Monte-Carlo Mass PDF eBook |
Author | Jan Kieseler |
Publisher | Springer |
Pages | 172 |
Release | 2016-06-15 |
Genre | Science |
ISBN | 3319400053 |
This thesis presents the first experimental calibration of the top-quark Monte-Carlo mass. It also provides the top-quark mass-independent and most precise top-quark pair production cross-section measurement to date. The most precise measurements of the top-quark mass obtain the top-quark mass parameter (Monte-Carlo mass) used in simulations, which are partially based on heuristic models. Its interpretation in terms of mass parameters used in theoretical calculations, e.g. a running or a pole mass, has been a long-standing open problem with far-reaching implications beyond particle physics, even affecting conclusions on the stability of the vacuum state of our universe. In this thesis, this problem is solved experimentally in three steps using data obtained with the compact muon solenoid (CMS) detector. The most precise top-quark pair production cross-section measurements to date are performed. The Monte-Carlo mass is determined and a new method for extracting the top-quark mass from theoretical calculations is presented. Lastly, the top-quark production cross-sections are obtained – for the first time – without residual dependence on the top-quark mass, are interpreted using theoretical calculations to determine the top-quark running- and pole mass with unprecedented precision, and are fully consistently compared with the simultaneously obtained top-quark Monte-Carlo mass.
Higher Order QCD Corrections to Single Top Quark Production
Title | Higher Order QCD Corrections to Single Top Quark Production PDF eBook |
Author | Mohammad Assadsolimani |
Publisher | disserta Verlag |
Pages | 161 |
Release | 2014-08 |
Genre | Science |
ISBN | 3954256746 |
It is known that the LHC has a considerable discovery potential because of its large centre-of-mass energy (vs =14 TeV) and the high design luminosity. In addition, the two experiments ATLAS and CMS perform precision measurements for numerous models in physics. The increasing experimental precision demands an even higher level of accuracy on the theoretical side. For a more precise prediction of outcomes, one has to consider the corrections obtained typically from Quantum Chromodynamics (QCD). The calculation of these corrections in the high energy regime is described by perturbation theory. In the present study, multi-loop calculations in QCD, including in particular two-loop corrections for single top quark production, are considered. There are several phenomenological motivations to study single top quark production: Firstly, the process is sensitive to the electroweak Wtb-vertex; moreover, non-standard couplings can hint at physics beyond the Standard Model. Secondly, the t-channel cross section measurement provides information on the b-quark Parton Distribution Functions (PDF). Finally, single top quark production enables us to directly measure the Cabibbo-Kobayashi-Maskawa(CKM) matrix element Vtb. The next-to-next-to-leading-order (NNLO) calculation of the single top quark production has many building blocks. In this study, two blocks will be presented: one-loop corrections squared and two-loop corrections interfered with Born. Initially, the one-loop squared contribution at NNLO for single top quark production will be calculated. Before we begin with the calculation of the two-loop corrections to single top quark production, we calculate the QCD form factors of heavy quarks at NNLO, along with the axial vector coupling as a first independent check. A comparison with the relevant literature suggests that this approach is in line with generally accepted procedure. This consistency check provides a proof of the validity of our setup. In the next step, the two-loop corrections to single top quark production will be calculated. After reducing all occurring tensor integrals to scalar integrals, we apply the integration by parts method (IBP) to find the master integrals. This step is a major challenge compared to all similar calculations because of the number of variables in the problem (two Mandelstam variables s and t, the dimension d and the mass of the top quark mt as well as the mass of the W boson mw). Finally, the calculation of the three kinds of topologies – vertex corrections, double boxes and non-planar double boxes – in the two-loop contribution at NNLO calculation will be presented.
The Evidence for the Top Quark
Title | The Evidence for the Top Quark PDF eBook |
Author | Kent W. Staley |
Publisher | Cambridge University Press |
Pages | 366 |
Release | 2004-04-05 |
Genre | Philosophy |
ISBN | 9780521827102 |
The Evidence for the Top Quark offers both a historical and philosophical perspective on an important recent discovery in particle physics: the first evidence for the elementary particle known as the top quark. Drawing on published reports, oral histories, and internal documents from the large collaboration that performed the experiment, Kent Staley explores in detail the controversies and politics that surrounded this major scientific result.At the same time the book seeks to defend an objective theory of scientific evidence based on error probabilities.
Top Quark Physics at Hadron Colliders
Title | Top Quark Physics at Hadron Colliders PDF eBook |
Author | Arnulf Quadt |
Publisher | Springer Science & Business Media |
Pages | 166 |
Release | 2007-08-16 |
Genre | Science |
ISBN | 3540710604 |
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.
Symmetry in Particle Physics
Title | Symmetry in Particle Physics PDF eBook |
Author | Michal Hnatič |
Publisher | MDPI |
Pages | 166 |
Release | 2021-06-24 |
Genre | Mathematics |
ISBN | 3039438018 |
Particle physics is a science about the symmetries of our world. The Standard Model is the fundamental theory of microworld. Particle dynamics in the Standard Model obeys strict symmetry laws with explicit experimental consequences. Priority problems of particle physics based on the Standard Model are more accurate theoretical predictions, experimental measurements and data analysis, proof of existence or non-existence of supersymmetry, top quark properties, Higgs boson, exotic quark states, and physics of neutrinos. In this collection of articles, many of these problems are discussed. We recommend this book for students, graduate students, and scientists working in the field of high energy physics.
Proton-antiproton Collider Physics - 8th Topical Workshop
Title | Proton-antiproton Collider Physics - 8th Topical Workshop PDF eBook |
Author | G Belletini |
Publisher | World Scientific |
Pages | 702 |
Release | 1990-07-19 |
Genre | |
ISBN | 981461193X |
The proceedings presents in a systematic way Top searches, Jets, Gauge Boson production, precision tests of electroweak theory, Ln s Physics, heavy Flavours and exotics. In addition, contributions to the sessions 'News from the World', 'Short term future' and 'Long term future' show the progress of SSC in USA, of LHC at CERN, UNK/VLEPP in USSR together with Perspectives of Hadron Collider Physics.