Download or read book Searches for Lorentz Violation in Top Quark Production and Decay at Hadron Colliders written by and published by . This book was released on 2012 with total page 224 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present a first-of-its-kind confirmation that the most massive known elementary particle obeys the special theory of relativity. Lorentz symmetry is a fundamental aspect of special relativity which posits that the laws of physics are invariant regardless of the orientation and velocity of the reference frame in which they are measured. Because this symmetry is a fundamental tenet of physics, it is important to test its validity in all processes. We quantify violation of this symmetry using the Standard-Model Extension framework, which predicts the effects that Lorentz violation would have on elementary particles and their interactions. The top quark is the most massive known elementary particle and has remained inaccessible to tests of Lorentz invariance until now. This model predicts a dependence of the production cross section for top and antitop quark pairs on sidereal time as the orientation of the experiment in which these events are produced changes with the rotation of the Earth. Using data collected with the DØ detector at the Fermilab Tevatron Collider, we search for violation of Lorentz invariance in events involving the production of a $t\bar{t}$ pair. Within the experimental precision, we find no evidence for such a violation and set upper limits on parameters describing its possible strength within the Standard-Model Extension. We also investigate the prospects for extending this analysis using the ATLAS detector at the Large Hadron Collider which, because of the higher rate of $t\bar{t}$ events at that experiment, has the potential to improve the limits presented here.
Download or read book Proceedings of the Fifth Meeting on CPT and Lorentz Symmetry Bloomington USA 28 June 2 July 2010 written by V. Alan Kostelecky and published by World Scientific. This book was released on 2011 with total page 311 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book contains the Proceedings of the Fifth Meeting on CPT and Lorentz Symmetry, held at Indiana University in Bloomington from June 28 to July 2, 2010. The Meeting focused on tests of these fundamental symmetries and on related theoretical issues, including scenarios for possible violations. Topics covered at the meeting include searches for CPT and Lorentz violations involving: birefringence and dispersion from cosmological sources, clock-comparison measurements, CMB polarization, electromagnetic resonant cavities, equivalence principle, gauge and Higgs particles, high-energy astrophysical observations, laboratory and gravimetric tests of gravity, matter interferometry, neutrino oscillations, oscillations and decays of K, D, B mesons, particle-antiparticle comparisons, post-newtonian gravity in the solar system and beyond, second- and third-generation particles, space-based missions, spectroscopy of hydrogen and antihydrogen, and spin polarized matter. Theoretical discussions include physical effects at the level of the Standard Model, General Relativity, and beyond; the possible origins and mechanisms for Lorentz and CPT violations; and related classical and quantum issues in field theory, particle physics, gravity, and string theory.
Download or read book Cpt And Lorentz Symmetry Proceedings Of The Eighth Meeting On Cpt And Lorentz Symmetry written by Lehnert Ralf and published by World Scientific. This book was released on 2020-04-04 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Cpt And Lorentz Symmetry Proceedings Of The Seventh Meeting written by V Alan Kostelecky and published by World Scientific. This book was released on 2017-01-18 with total page 318 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book contains the Proceedings of the Seventh Meeting on CPT and Lorentz Symmetry, held at Indiana University in Bloomington on June 20-24, 2016. The meeting focused on tests of these fundamental symmetries and on related theoretical issues, including scenarios for possible violations.Topics covered at the meeting include experimental and observational searches for CPT and Lorentz violation involving: accelerator and collider experiments; astrophysical birefringence, dispersion, and anisotropy; atomic and molecular spectroscopy; clock-comparison measurements; CMB polarization; decays of atoms, nuclei, and particles; equivalence-principle tests with matter and antimatter; exotic atoms, muonium, positronium; gauge and Higgs particles; gravimetry; gravitational waves; high-energy astrophysical observations; hydrogen and antihydrogen; matter interferometry; neutrino oscillations and propagation, neutrino-antineutrino mixing; oscillations and decays of K, B, D mesons; particle-antiparticle comparisons; post-Newtonian gravity in the solar system and beyond; resonant cavities lasers; second and third-generation particles; sidereal and annual time variations, compass asymmetries; space-based missions; spin-polarized matter; spin precession; tests of short-range gravity; and time-of-flight measurements. Theoretical and phenomenological discussions include: physical effects at the level of the Standard Model, General Relativity, and beyond; origins and mechanisms for violations; classical and quantum field theory, gravitation, particle physics, and strings; mathematical foundations; and Finsler geometry.
Download or read book Search for Heavy Resonances Decaying to Top Quark Pairs in the Boosted All Hadronic Decay Channel written by Trisha Farooque and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Physics at the Large Hadron Collider written by Amitava Datta and published by Springer Science & Business Media. This book was released on 2010-05-30 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt: In an epoch when particle physics is awaiting a major step forward, the Large Hydron Collider (LHC) at CERN, Geneva will soon be operational. It will collide a beam of high energy protons with another similar beam circulation in the same 27 km tunnel but in the opposite direction, resulting in the production of many elementary particles some never created in the laboratory before. It is widely expected that the LHC will discover the Higgs boson, the particle which supposedly lends masses to all other fundamental particles. In addition, the question as to whether there is some new law of physics at such high energy is likely to be answered through this experiment. The present volume contains a collection of articles written by international experts, both theoreticians and experimentalists, from India and abroad, which aims to acquaint a non-specialist with some basic issues related to the LHC. At the same time, it is expected to be a useful, rudimentary companion of introductory exposition and technical expertise alike, and it is hoped to become unique in its kind. The fact that there is substantial Indian involvement in the entire LHC endeavour, at all levels including fabrication, physics analysis procedures as well as theoretical studies, is also amply brought out in the collection.
Download or read book Top Quark Pair Production and Decay at Hadron Colliders written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Measurement of WZ Production and Searches for Anomalous Top Quark Decays and Higgs Boson Production Using Tri lepton Final States in p bar p Collisions at sqrt s written by and published by . This book was released on 2012 with total page 211 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present the results of three analyses; a $WZ$ production cross section measurement, a search for new physics in anomalous top quark decays, and the search for the standard model Higgs boson, all with final states of three or more leptons -- either electrons or muons -- plus an imbalance of transverse momentum using Tevatron proton and anti-proton collisions at a center--of--mass energy of $\sqrt{s}$ = 1.96 TeV with the D0 detector at the Fermi National Accelerator Laboratory in Chicago, IL. The first analysis reports a measurement of the $WZ \rightarrow \ell^{\prime}\nu\ell\bar{\ell}$ cross section. Using 4.1 $fb^{-1}$ of integrated luminosity, we measure a cross section of 3.90$_{-0.85}^{+1.01}$($stat+syst$) $\pm$ 0.31($lumi$) pb, which is found to be in good agreement with the standard model prediction. The second analysis is an extension of the first, in which we use the same dataset and look for the flavor changing neutral current decay of $t \rightarrow Zq$ in $p\bar {p} \rightarrow t\bar{t} \rightarrow WbZq \rightarrow \ell^{\prime}\nu\ell\bar{\ell} + \rm{jets}$ decays. Here $q$ is considered to be either a $u$ or $c$ quark, and both the $q$ and $b$ quarks decay hadronically. We find no evidence of flavor changing neutral current production and set upper limits on the branching ratio of $BR(t \rightarrow Zq)
Download or read book Top Quark Physics at Hadron Colliders written by Arnulf Quadt and published by Springer Science & Business Media. This book was released on 2007-08-16 with total page 166 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Search for Baryon Number Violation in Top quark Decays written by and published by . This book was released on 2014 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: A search for baryon number violation (BNV) in top-quark decays is performed using pp collisions produced by the LHC at sqrt(s) = 8 TeV. The top-quark decay considered in this search results in one light lepton (muon or electron), two jets, but no neutrino in the final state. Data used for the analysis were collected by the CMS detector and correspond to an integrated luminosity of 19.5 inverse femtobarns. The event selection is optimized for top quarks produced in pairs, with one undergoing the BNV decay and the other the standard model hadronic decay to three jets. No significant excess of events over the expected yield from standard model processes is observed. The upper limits at 95% confidence level on the branching fraction of the BNV top-quark decay are calculated to be 0.0016 and 0.0017 for the muon and the electron channels, respectively. Assuming lepton universality, an upper limit of 0.0015 results from the combination of the two channels. These limits are the first that have been obtained on a BNV process involving the top quark.
Download or read book Single Top Quark Production and Decay in Hadron Collision at Next to leading Order written by Qinghong Cao and published by . This book was released on 2005 with total page 466 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Top Quark Pair Productions and Decay at Hadron Colliders written by W. Bernreuther and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Top Quark Pair Production and Decay Including Spin Effects at Hadron Colliders written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Search for Top antitop Quark Resonances with the ATLAS Detector at the Large Hadron Collider written by Bertrand Chapleau and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "The intriguing nature of the top quark, by far the heaviest particle in the Standard Model of particle physics, has motivated the development of many theoretical extensions predicting the existence of new massive particles decaying to a pair of top-antitop quarks. The production of these hypothetical particles in proton-proton collisions at the Large Hadron Collider would reveal itself as a resonance in the expected smooth distribution of the top-antitop quark invariant mass. This thesis presents a search for such a new heavy particle decaying to a pair of top-antitop quarks in the semi-leptonic final state. The analyzed data sample amounts to a total of 4.6 fb-1 at a proton-proton collision center-of-mass energy of 7 TeV. Novel techniques specifically tailored to the identification of the decay products of highly energetic top quarks are developed and used. No evidence for resonant production of pairs of top-antitop quarks is found and, as a result, constraints are set on two theoretical models. Upper limits on the production cross-section times branching ratio are established at a 95% credibility level for a leptophobic Zʹ boson from the Topcolor model, and a Kaluza-Klein gluon from the Randall-Sundrum model. The Zʹ boson and the Kaluza-Klein gluon are excluded to exist (at a 95% credibility level) in the mass ranges 0.8-1.65 TeV and 0.8-1.88 TeV, respectively. The constraints de- rived in this thesis on the two theoretical models are more stringent than the ones obtained at other experiments, thanks to the large center-of-mass energy and the dedicated high-energy top quark identification techniques used." --
Download or read book Top Quark Pair Production and Decay at Hadron Colliders written by and published by . This book was released on 2002 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Heavy Flavor Physics at Hadron Colliders written by and published by . This book was released on 1991 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: The search for the top quark has dominated heavy flavor physics at hadron colliders. For Standard model decay of top the present mass limit in m{sub t}> 89 GeV (95% C.L.). Bottom production cross sections are quite large at hadron colliders, thus providing enough statistics for extensive studies. Results on cross sections, B° - {bar B}° mixing, exclusive channels and rare B decays will be summarized.
Download or read book Top Quark Pair Production and Decay at Hadron Colliders written by and published by . This book was released on 2002 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt:
