Measurement of the Top Quark Pair Production Cross Section in Dilepton Final States Containing One Τ Lepton in Pp Collisions at √s
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Published: 2019
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Measurement of the Top Quark Pair Production Cross Section in Pp Collisions at Sqrt(s)
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Published: 2012
Total Pages: 31
ISBN-13:
DOWNLOAD EBOOKThe top quark pair production cross section is measured in dilepton events with one electron or muon, and one hadronically decaying tau lepton from the decay t anti-t to (l nu(l)) (tau nu(tau)) b anti-b, where l can be either an electron or a muon. The data sample corresponds to an integrated luminosity of 2.0 inverse femtobarns for the electron channel and 2.2 inverse femtobarns for the muon channel, collected by the CMS detector at the LHC. This is the first measurement of the t anti-t cross section explicitly including tau leptons in proton-proton collisions at sqrt(s)=7 TeV. The measured value sigma(t anti-t) = 143 +/- 14 (stat.) +/- 22 (syst.) +/- 3 (lumi.) pb is consistent with the standard model predictions.
Top Quark Pair Production
Author: Anna Christine Henrichs
Publisher: Springer Science & Business Media
Published: 2013-10-04
Total Pages: 231
ISBN-13: 3319014870
DOWNLOAD EBOOKBefore 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.
Measurement of the Top Quark Mass in the Dilepton Final State Using the Matrix Element Method
Author: Alexander Grohsjean
Publisher: Springer Science & Business Media
Published: 2010-10-01
Total Pages: 155
ISBN-13: 364214070X
DOWNLOAD EBOOKThe main pacemakers of scienti?c research are curiosity, ingenuity, and a pinch of persistence. Equipped with these characteristics a young researcher will be s- cessful in pushing scienti?c discoveries. And there is still a lot to discover and to understand. In the course of understanding the origin and structure of matter it is now known that all matter is made up of six types of quarks. Each of these carry a different mass. But neither are the particular mass values understood nor is it known why elementary particles carry mass at all. One could perhaps accept some small generic mass value for every quark, but nature has decided differently. Two quarks are extremely light, three more have a somewhat typical mass value, but one quark is extremely massive. It is the top quark, the heaviest quark and even the heaviest elementary particle that we know, carrying a mass as large as the mass of three iron nuclei. Even though there exists no explanation of why different particle types carry certain masses, the internal consistency of the currently best theory—the standard model of particle physics—yields a relation between the masses of the top quark, the so-called W boson, and the yet unobserved Higgs particle. Therefore, when one assumes validity of the model, it is even possible to take precise measurements of the top quark mass to predict the mass of the Higgs (and potentially other yet unobserved) particles.
Top-Quark Pair Production Cross Sections and Calibration of the Top-Quark Monte-Carlo Mass
Author: Jan Kieseler
Publisher: Springer
Published: 2016-06-15
Total Pages: 172
ISBN-13: 3319400053
DOWNLOAD EBOOKThis 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.
Top Quark Physics at Hadron Colliders
Author: Arnulf Quadt
Publisher: Springer Science & Business Media
Published: 2007-08-16
Total Pages: 166
ISBN-13: 3540710604
DOWNLOAD EBOOKThis 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.
Spin Correlations in tt Events from pp Collisions
Author: Boris Lemmer
Publisher: Springer
Published: 2015-06-24
Total Pages: 246
ISBN-13: 3319189328
DOWNLOAD EBOOKThis thesis introduces readers to the Standard Model, the top quark and its properties, before explaining the concept of spin correlation measurement. The first measurement of top quark spin correlations at the LHC in the lepton+jets decay channel is presented. As the heaviest elementary particle, the top quark plays an essential role in the Standard Model of elementary particle physics. In the case of top quarks being produced in pairs at hadron colliders, the Standard Model predicts their spins to be correlated. The degree of correlation depends on both the production mechanism and properties of the top quark. Any deviation from the Standard Model prediction can be an indicator for new physics phenomena. The thesis employs an advanced top quark reconstruction algorithm including dedicated identification of the up- and down-type quarks from the W boson decay.
Proceedings of the XXV DAE-BRNS High Energy Physics (HEP) Symposium 2022, 12–16 December, Mohali, India
Author: Satyajit Jena
Publisher: Springer Nature
Published:
Total Pages: 1353
ISBN-13: 9819702895
DOWNLOAD EBOOKMeasurement of the Top Anti-top Quark Pair Production Cross Section in the Dilepton Decay Channel Using Lepton+Track Selection in 7 TeV P - P Collisions with L
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Published: 2012
Total Pages:
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DOWNLOAD EBOOKLepton Photon Interactions At High Energies (Lepton Photon 2017) - Proceedings Of The 28th International Symposium
Author: Wang Wei
Publisher: World Scientific
Published: 2020-02-27
Total Pages: 576
ISBN-13: 9811207410
DOWNLOAD EBOOKThe latest of the 'Lepton Photon' symposium, one of the well-established series of meetings in the high-energy physics community, was successfully organized at the South Campus of Sun Yat-sen University, Guangzhou, China, from August 7-12, 2017, where physicists around the world gathered to discuss the latest advancements in the research field.This proceedings volume of the Lepton Photon 2017 collects contributions by the plenary session speakers and the posters' presenters, which cover the latest results in particle physics, nuclear physics, astrophysics, cosmology, and plans for future facilities.
