Search for Single Production of a Vector-like Quark Via a Heavy Gluon in the 4b Final State with the ATLAS Detector in Pp Collisions at [mml

Search for Single Production of a Vector-like Quark Via a Heavy Gluon in the 4b Final State with the ATLAS Detector in Pp Collisions at [mml PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 20

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Book Description
In this study, a search is performed for the process pp → G* → BH$\bar{b}$/$\bar{B}$Hb → H$b\bar{b}$→ $b\bar{b}b\bar{b}$, predicted in composite Higgs scenarios, where G* is a heavy colour octet vector resonance and BHBH a vector-like quark of charge -1/3. The data were obtained from pp collisions at a centre-of-mass energy of 8 TeV corresponding to an integrated luminosity of 19.5 fb-1, recorded by the ATLAS detector at the LHC. The largest background, multijet production, is estimated using a data-driven method. No significant excess of events with respect to Standard Model predictions is observed, and upper limits on the production cross section times branching ratio are set. Comparisons to the predictions from a specific benchmark model are made, resulting in lower mass limits in the two-dimensional mass plane of mG* vs. mBH.

Search for Single Production of a Vector-like Quark Via a Heavy Gluon in the 4b Final State with the ATLAS Detector in Pp Collisions at [mml

Search for Single Production of a Vector-like Quark Via a Heavy Gluon in the 4b Final State with the ATLAS Detector in Pp Collisions at [mml PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 20

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Book Description
In this study, a search is performed for the process pp → G* → BH$\bar{b}$/$\bar{B}$Hb → H$b\bar{b}$→ $b\bar{b}b\bar{b}$, predicted in composite Higgs scenarios, where G* is a heavy colour octet vector resonance and BHBH a vector-like quark of charge -1/3. The data were obtained from pp collisions at a centre-of-mass energy of 8 TeV corresponding to an integrated luminosity of 19.5 fb-1, recorded by the ATLAS detector at the LHC. The largest background, multijet production, is estimated using a data-driven method. No significant excess of events with respect to Standard Model predictions is observed, and upper limits on the production cross section times branching ratio are set. Comparisons to the predictions from a specific benchmark model are made, resulting in lower mass limits in the two-dimensional mass plane of mG* vs. mBH.

Search for Single Production of a Vector-like Quark Via a Heavy Gluon in the 4b Final State with the ATLAS Detector in Pp Collisions at

Search for Single Production of a Vector-like Quark Via a Heavy Gluon in the 4b Final State with the ATLAS Detector in Pp Collisions at PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 20

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Book Description
In this study, a search is performed for the process pp → G* → BH$ar{b}$/$ar{B}$Hb → H$bar{b}$→ $bar{b}bar{b}$, predicted in composite Higgs scenarios, where G* is a heavy colour octet vector resonance and BHBH a vector-like quark of charge –1/3. The data were obtained from pp collisions at a centre-of-mass energy of 8 TeV corresponding to an integrated luminosity of 19.5 fb–1, recorded by the ATLAS detector at the LHC. The largest background, multijet production, is estimated using a data-driven method. No significant excess of events with respect to Standard Model predictions is observed, and upper limits on the production cross section times branching ratio are set. Comparisons to the predictions from a specific benchmark model are made, resulting in lower mass limits in the two-dimensional mass plane of mG* vs. mBH.

Advances in Jet Substructure at the LHC

Advances in Jet Substructure at the LHC PDF Author: Roman Kogler
Publisher: Springer Nature
ISBN: 3030728587
Category : Science
Languages : en
Pages : 287

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Book Description
This book introduces the reader to the field of jet substructure, starting from the basic considerations for capturing decays of boosted particles in individual jets, to explaining state-of-the-art techniques. Jet substructure methods have become ubiquitous in data analyses at the LHC, with diverse applications stemming from the abundance of jets in proton-proton collisions, the presence of pileup and multiple interactions, and the need to reconstruct and identify decays of highly-Lorentz boosted particles. The last decade has seen a vast increase in our knowledge of all aspects of the field, with a proliferation of new jet substructure algorithms, calculations and measurements which are presented in this book. Recent developments and algorithms are described and put into the larger experimental context. Their usefulness and application are shown in many demonstrative examples and the phenomenological and experimental effects influencing their performance are discussed. A comprehensive overview is given of measurements and searches for new phenomena performed by the ATLAS and CMS Collaborations. This book shows the impressive versatility of jet substructure methods at the LHC.

Search for New Phenomena in Top-Antitop Quarks Final States with Additional Heavy-Flavour Jets with the ATLAS Detector

Search for New Phenomena in Top-Antitop Quarks Final States with Additional Heavy-Flavour Jets with the ATLAS Detector PDF Author: Daiki Yamaguchi
Publisher: Springer Nature
ISBN: 9811509328
Category : Science
Languages : en
Pages : 279

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Book Description
This book reports on the search for a new heavy particle, the Vector-Like Top quark (VLT), in the Large Hadron Collider (LHC) at CERN. The signal process is the pair production of VLT decaying into a Higgs boson and top quark (TT→Ht+X, X=Ht, Wb, Zt). The signal events result in top–antitop quarks final states with additional heavy flavour jets. The book summarises the analysis of the data collected with the ATLAS detector in 2015 and 2016. In order to better differentiate between signals and backgrounds, exclusive taggers of top quark and Higgs boson were developed and optimised for VLT signals. These efforts improved the sensitivity by roughly 30%, compared to the previous analysis. The analysis outcomes yield the strongest constraints on parameter space in various BSM theoretical models. In addition, the book addresses detector operation and the evaluation of tracking performance. These efforts are essential to properly collecting dense events and improving the accuracy of the reconstructed objects that are used for particle identification. As such, they represent a valuable contribution to data analysis in extremely dense environments.

Phenomena Beyond the Standard Model: What Do We Expect for New Physics to Look Like?

Phenomena Beyond the Standard Model: What Do We Expect for New Physics to Look Like? PDF Author: Roman Pasechnik
Publisher: Frontiers Media SA
ISBN: 2889639908
Category : Science
Languages : en
Pages : 180

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Book Description
This eBook is a collection of articles from a Frontiers Research Topic. Frontiers Research Topics are very popular trademarks of the Frontiers Journals Series: they are collections of at least ten articles, all centered on a particular subject. With their unique mix of varied contributions from Original Research to Review Articles, Frontiers Research Topics unify the most influential researchers, the latest key findings and historical advances in a hot research area! Find out more on how to host your own Frontiers Research Topic or contribute to one as an author by contacting the Frontiers Editorial Office: frontiersin.org/about/contact.

A Search for the Single Production of Vector-like Quarks Decaying to a W-boson and a B-quark in the Leptonic Final State with the ATLAS Detector

A Search for the Single Production of Vector-like Quarks Decaying to a W-boson and a B-quark in the Leptonic Final State with the ATLAS Detector PDF Author: Ferdinand Schenck
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Book Description


Particle Physics: Perspectives And Opportunities - Report Of The Dpf Committee On Long-term Planning

Particle Physics: Perspectives And Opportunities - Report Of The Dpf Committee On Long-term Planning PDF Author: Robert N Cahn
Publisher: World Scientific
ISBN: 9814549223
Category :
Languages : en
Pages : 318

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Book Description
This book is the result of a broad-based and in-depth study of high energy physics commissioned by the Executive Committee of the Division of Particles and Fields of the American Physical Society. This year-long study was initiated in the early 1994, in the wake of the cancellation of the SSC, and is meant to complement the report of the Drell HEPAP subpanel, charged with providing a vision for the future of the field. The DPF study of high energy physics was organized on the basis of the working groups, each led by a number of co-conveners chosen among established leaders in the various subspecialties in the field. These conveners, in turn, organized their working groups by inviting other active workers in the discipline to participate and gathered further input from the community by holding a variety of specialized meetings and workshops. This book contains the final reports of the 11 working groups assembled for the study, along with an extended overview and executive summary by the editors.

Heavy Flavours

Heavy Flavours PDF Author: A J Buras
Publisher: World Scientific
ISBN: 9814602825
Category :
Languages : en
Pages : 803

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Book Description
This volume is a collection of review articles on the most outstanding topics in heavy flavour physics. All the authors have made significant contributions to this field. The book reviews in detail the theoretical structure of heavy flavour physics within the Standard Model and its confrontation with existing experimental data.The physics of the top quark and of the Higgs play an important role in this volume. Beginning with radiative electroweak corrections and their impressive tests at LEP and hadron colliders, the book summarizes the present status of quark mixing, CP violation and rare decays. The dynamics of exclusive D- and B-meson decays, the τ-lepton physics and the newly discovered heavy quark symmetries are discussed in detail. The impact of strong interactions on weak decays is clearly visible in many articles. The physics of heavy flavours at LEP, HERA and hadron colliders constitutes an important part of the book. Another significant topic is the possible role of heavy flavours in the spontaneous symmetry breaking of gauge symmetries. Finally the most recent advances in lattice calculations of the properties of heavy flavours and the lattice studies of the dynamics of heavy flavours are presented.

Looking Inside Jets

Looking Inside Jets PDF Author: Simone Marzani
Publisher: Springer
ISBN: 3030157091
Category : Science
Languages : en
Pages : 205

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Book Description
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.

Physics at the Terascale

Physics at the Terascale PDF Author: Ian Brock
Publisher: John Wiley & Sons
ISBN: 3527634975
Category : Science
Languages : en
Pages : 437

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Book Description
Written by authors working at the forefront of research, this accessible treatment presents the current status of the field of collider-based particle physics at the highest energies available, as well as recent results and experimental techniques. It is clearly divided into three sections; The first covers the physics -- discussing the various aspects of the Standard Model as well as its extensions, explaining important experimental results and highlighting the expectations from the Large Hadron Collider (LHC). The second is dedicated to the involved technologies and detector concepts, and the third covers the important - but often neglected - topics of the organisation and financing of high-energy physics research. A useful resource for students and researchers from high-energy physics.