Download or read book Measurement of Top Pair Production Cross Section in Electron Jets Channel in Ppbar Collisions at square Root Of S written by Chunhui Han and published by . This book was released on 2003 with total page 298 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Measurement of the TtH Production Cross section with a Collimated H Bb Decay in Pp Collisions at Sqrt s written by Eftychia Tzovara and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The predictions of the Standard Model (SM) of particle physics have been probed with remarkable accuracy, so far. The Large Hadron Collider (LHC) at CERN has significantly contributed to this quest. A remarkable achievement of the ATLAS and CMS experiments at the LHC was the discovery of the Higgs boson in 2012, the last missing piece of the SM. With the increasing amount of proton-proton collisions delivered by the LHC, more precise measurements of the Higgs boson are now possible, while rare processes are accessible as well. A property of the Higgs boson that is of particular importance is its coupling to the top quark, which is expected to be the strongest in the SM due to the high mass of the top quark. Therefore, its precise measurement is a stringent test of the SM. A direct measurement of the top-quark Yukawa coupling can be assessed through the Higgs-boson production in association with a pair of top quarks (ttH). This thesis presents the measurement of the ttH process with a subsequent Higgs-boson decay to a pair of b-quarks (H -> bb), the decay mode with the largest branching ratio. The measurement is performed with data collected by the ATLAS detector, corresponding to an integrated luminosity of 139 fb^-1 at a center-of-mass energy of 13 TeV. Events with one or two charged leptons from the tt decay in the final state are considered to the measurement. The main challenge of the ttH(H -> bb) channel emerges from the large SM backgrounds from the production of top-quark pairs with additional jets (tt+jets). Also the many jets coming from b-hadrons (b-jets) in the final state cause combinatorial ambiguities. Thus, the identification of such jets is decisive in order to determine the signal and reject many background processes. The ttH events are split into exclusive analysis regions, based on the number of leptons, jets, and jets tagged as b-jets, providing regions enhanced in signal, or in the main background components. Specifically in the single-lepton channel, a boosted category is defined by selecting events in which the Higgs boson and possibly also the hadronically decaying top quark are produced with high transverse momentum (pT), with their decay products being collimated in large-radius jets. The single-lepton boosted channel targets events with Higgs-boson candidate pT >= 300 GeV and is the main scope of this thesis. To identify the reconstructed objects with the underlying particles and to maximise the discrimination of the ttH signal from the overwhelming tt+jets background events in the signal-enriched regions, machine-learning algorithms are employed. The background is dominated by a tt process with an additional gluon in the final state which further splits into a pair of b-quarks (tt+bb). Besides, a large number of heavy-flavour jets in the final state is not well modelled, thus many systematic uncertainties have to be considered, decreasing the sensitivity of the measurement. All the defined analysis regions are analysed together in a combined profile likelihood fit to test for the presence of signal. The fit simultaneously determines the event yields for the signal and the most important background component, while constraining the overall background model within the assigned systematic uncertainties. Eventually, the ratio of the measured ttH cross section to the SM expectation in the inclusive cross-section measurement is found to be 0.35 +0.36,-0.34}, corresponding to an observed (expected) significance of 1.0 (2.7) standard deviations. A ttH signal strength larger than the SM prediction is excluded at 95% confidence level. The measurement uncertainty is dominated by systematic uncertainties, mainly regarding the theoretical knowledge of the tt +>= 1b background process. Finally, to further test the SM, the cross-section is measured differentially as a function of the generator-level Higgs-boson pT, taking advantage of the reconstruction of the Higgs-boson kinematics.
Download or read book Report of Research Activities written by Yale University. Cowles Foundation for Research in Economics and published by . This book was released on 1959 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Topological Geometrodynamics written by Matti Pitkanen and published by Bentham Science Publishers. This book was released on 2016-03-03 with total page 1235 pages. Available in PDF, EPUB and Kindle. Book excerpt: Topological geometrodynamics (TGD) is a modification of the theory of general relativity inspired by the problems related to the definition of inertial and gravitational energies in the earlier hypotheses. TGD is also a generalization of super string models. TGD brings forth an elegant theoretical projection of reality and builds upon the work by renowned scientists (Wheeler, Feynman, Penrose, Einstein, Josephson to name a few). In TGD, Physical space-time planes are visualized as four-dimensional surfaces in a certain 8-dimensional space (H). The choice of H is fixed by symmetries of standard model and leads to a geometric mapping of known classical fields and elementary particle numbers. TGD differs from Einstein’s geometrodynamics in the way space-time planes or ‘sheets’ are lumped together. Extending the theory based on fusing number concepts implies a further generalisation of the space-time concept allowing the identification of space-time correlates of cognition and intentionality. Additionally, zero energy ontology forces an extension of quantum measurement theory to a theory of consciousness and a hierarchy of phases is identified. Dark matter is thus predicted with far reaching implications for the understanding of consciousness and living systems. Therefore, it sets a solid foundation for modeling our universe in geometric terms. Topological Geometrodynamics: An Overview explains basic and advanced concepts about TGD. The book covers introductory information and classical TGD concepts before delving into twistor-space theory, particle physics, infinite-dimensional spinor geometry, generalized number theory, Planck constants, and the applications of TGD theory in research. The book is a valuable guide to TDG theory for researchers and advanced graduates in theoretical physics and cosmology.
Download or read book The Standard Model written by Cliff Burgess and published by Cambridge University Press. This book was released on 2007 with total page 566 pages. Available in PDF, EPUB and Kindle. Book excerpt: This 2006 book uses the standard model as a vehicle for introducing quantum field theory.
Download or read book Flora of North America North of Mexico written by and published by . This book was released on 2014 with total page 729 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Measurement of the Diphoton Differential Cross section in P bar P Collisions at square Root S written by Joshua Marc Dyer and published by . This book was released on 2007 with total page 202 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Spin Correlations in Tt Events from Pp Collisions written by Boris Lemmer and published by . This book was released on 2015 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This 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.
Download or read book The Bible in Ancient and Modern Media written by Holly Hearon and published by Wipf and Stock Publishers. This book was released on 2009-01-01 with total page 201 pages. Available in PDF, EPUB and Kindle. Book excerpt: This cutting-edge volume has been brought together in honor of Thomas Boomershine, author, scholar, storyteller, innovator. The particular occasion inviting this recognition of his work is the twenty-fifth anniversary of the Society of Biblical Literature's section on The Bible in Ancient and Modern Media (BAMM), which Tom was instrumental in founding. For two and half decades this program unit has provided scholars with opportunities to explore and experience biblical material in media other than silent print, including both oral and multimedia electronic performances. This book explores many, though by no means all, of the issues lifted up in those sessions over the years. Contributors A. K. M. Adam Adam Gilbert Bartholomew Arthur J. Dewey Dennis Dewey Joanna Dewey Robert M. Fowler Holly E. Hearon David Rhoads Philip Ruge-Jones Whitney T. Shiner Marti J. Steussy Richard W. Swanson
Download or read book Hadron Collider Physics written by Harry Weerts and published by American Institute of Physics. This book was released on 2005-04-07 with total page 492 pages. Available in PDF, EPUB and Kindle. Book excerpt: East Lansing, Michigan, 14-18 June 2004
Download or read book The Boundaries of the Criminal Law written by R.A. Duff and published by Oxford University Press. This book was released on 2010-11-11 with total page 278 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is the first book of a series on criminalization - examining the principles and goals that should guide what kinds of conduct are to be criminalized, and the forms that criminalization should take. The first volume studies the scope and boundaries of the criminal law - asking what principled limits might be placed on criminalizing behaviour.
Download or read book Fifty Years of Indian Agriculture written by Ali Mohammad and published by Concept Publishing Company. This book was released on 2007 with total page 372 pages. Available in PDF, EPUB and Kindle. Book excerpt: Contributed papers presented at the conference organized by Dept. of Geography, Aligarh Muslim University.
Download or read book Glimpses of Indian Agriculture written by Sanwar M. Jharwal and published by Academic Foundation. This book was released on 2008 with total page 1036 pages. Available in PDF, EPUB and Kindle. Book excerpt: Authentic and authoritative, this presentation shares a comprehensive overview of the extensive research undertaken by the Agro Economic Research Centers (AERCs) and the concerns confronting Indian agriculture. Established across the states in India to provide policy feedback to the Ministry of Agriculture, the AERCs generated many important research initiatives and debates over five decades. This second volume focuses on the problems confronted at the regional level by each of the participating states.
Download or read book Lie Theory and Its Applications in Physics written by Vladimir Dobrev and published by Springer Nature. This book was released on 2020-10-15 with total page 552 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume presents modern trends in the area of symmetries and their applications based on contributions to the workshop "Lie Theory and Its Applications in Physics" held near Varna (Bulgaria) in June 2019. Traditionally, Lie theory is a tool to build mathematical models for physical systems. Recently, the trend is towards geometrization of the mathematical description of physical systems and objects. A geometric approach to a system yields in general some notion of symmetry, which is very helpful in understanding its structure. Geometrization and symmetries are meant in their widest sense, i.e., representation theory, algebraic geometry, number theory, infinite-dimensional Lie algebras and groups, superalgebras and supergroups, groups and quantum groups, noncommutative geometry, symmetries of linear and nonlinear partial differential operators, special functions, and others. Furthermore, the necessary tools from functional analysis are included. This is a large interdisciplinary and interrelated field. The topics covered in this volume from the workshop represent the most modern trends in the field : Representation Theory, Symmetries in String Theories, Symmetries in Gravity Theories, Supergravity, Conformal Field Theory, Integrable Systems, Polylogarithms, and Supersymmetry. They also include Supersymmetric Calogero-type models, Quantum Groups, Deformations, Quantum Computing and Deep Learning, Entanglement, Applications to Quantum Theory, and Exceptional Quantum Algebra for the standard model of particle physics This book is suitable for a broad audience of mathematicians, mathematical physicists, and theoretical physicists, including researchers and graduate students interested in Lie Theory.
Download or read book Measurement of the Top Quark Mass written by Tzu-Chung Frank Hsieh and published by . This book was released on 1998 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book X Ray Lasers 2018 written by Michaela Kozlová and published by Springer Nature. This book was released on 2020-03-06 with total page 207 pages. Available in PDF, EPUB and Kindle. Book excerpt: These proceedings gather a selection of invited and contributed papers presented during the 16th International Conference on X-Ray Lasers (ICXRL 2018), held in Prague, Czech Republic, from 7 to 12 October 2018. The conference is part of an ongoing series dedicated to recent developments in the science and technology of X-ray lasers and other coherent X-ray sources, with an additional focus on supporting technologies, instrumentation and applications. The book highlights advances in a wide range of fields including laser and discharge-pumped plasma X-ray lasers, the injection and seeding of X-ray amplifiers, high-order harmonic generation and ultrafast phenomena, X-ray free electron lasers, novel schemes for (in)coherent XUV, X-ray and γ-ray generation, XUV and X-ray imaging, optics and metrology, X-rays and γ-rays for fundamental science, the practical implementation of X-ray lasers, XFELs and super-intense lasers, and the applications and industrial uses of X-ray lasers.
Download or read book Nuclei in the Cosmos written by Heinz Oberhummer and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 242 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nuclear astrophysics as it stands today is a fascinating science. Even though, compared to other scientific fields, it is a young discipline which has developed only in this century, it has answered many questions concerning the under standing of our cosmos. One of these great achievements was the concept of nucleosynthesis, the creation of the elements in the early universe in interstellar matter and in stars. Nuclear astrophysics has continued, to solve many riddles of the evolution of the myriads of stars in our cosmos. This review volume attempts to provide an overview of the current status of nuclear astrophysics. Special emphasis is given to the interdisciplinary nature of the field: astronomy, nuclear physics, astrophysics and particle physics are equally involved. One basic effort of nuclear astrophysics is the collection of ob servational facts with astronomical methods. Laboratory studies of the nuclear processes involved in various astrophysical scenarios have provided fundamen tal information serving both as input for and test of astrophysical models. The theoretical understanding of nuclear reaction mechanisms is necessary, for example, to extrapolate the experimentally determined reaction rates to the thermonuclear energy range, which is relevant for the nuclear processes in our cosmos. Astrophysical models and calculations allow us to simulate how nuclear processes contribute to driving the evolution of stars, interstellar matter and the whole universe. Finally, elementary particle physics also plays an important role in the field of nuclear astrophysics, for instance through weak interaction processes involving neutrinos.
