Download or read book A Search for Long Lived Particles that Decay to Muons Using the ATLAS Detector written by Melissa Yexley and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Search for Displaced Leptons in the ATLAS Detector written by Lesya Horyn and published by Springer Nature. This book was released on 2022-02-07 with total page 146 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis presents a search for long-lived particles decaying into displaced electrons and/or muons with large impact parameters. This signature provides unique sensitivity to the production of theoretical lepton-partners, sleptons. These particles are a feature of supersymmetric theories, which seek to address unanswered questions in nature. The signature searched for in this thesis is difficult to identify, and in fact, this is the first time it has been probed at the Large Hadron Collider (LHC). It covers a long-standing gap in coverage of possible new physics signatures. This thesis describes the special reconstruction and identification algorithms used to select leptons with large impact parameters and the details of the background estimation. The results are consistent with background, so limits on slepton masses and lifetimes in this model are calculated at 95% CL, drastically improving on the previous best limits from the Large Electron Positron Collider (LEP).
Download or read book Search for Out of time Decays of Stopped Particles at the ATLAS Detector written by Josh Cogan and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: On July 4th 2012, the ATLAS and CMS experiments announced the discovery of a new particle, later declared to be one of possibly many Higgs bosons. The Higgs mechanism has been so successful explaining several striking features of fundamental particle physics it was the topic of the 2013 Nobel Prize in physics. However, this mechanism provides a few problems of it's own. Most importantly, both the mass of the new Higgs boson and the cosmological constant must be extremely fine-tuned to produce a universe remotely similar to the one we observe today. Supersymmetry, a hypothetical extension to the current theory, addresses many problems in theoretical and experimental physics including the fine-tuned Higgs mass. In this work, a variant, called Split-Supersymmetry, is investigated; it avoids some problems in standard Supersymmetry while explicitly leaving the Higgs mass fine-tuned. A experimentally unique feature of Split-Supersymmetry is the production of R-hadrons--composite, massive, long-lived, particles. Indeed such long-lived states are predicted in several scenarios of physics beyond the Standard Model, and this search is sensitive to them as well. This dissertation describes the ATLAS searches using 2010, 2011 and 2012 data for gluino and squark R-hadrons which have come to rest within the ATLAS detector, particularly the calorimeter, and decay at some later time to jets or "ttbar" and a neutralino. Candidate decay events are triggered in the empty bunch crossings in order to remove collision backgrounds. Selections based on jet shape and muon-system activity are applied to discriminate events from backgrounds, the largest of which are cosmic and beam-halo muons. In the absence of a excess, limits are placed on the new particle mass as a function of its lifetime, for various neutralino masses and decay types.
Download or read book Search for Long lived Neutral Particles in Final States with a Muon and Multi track Displaced Vertex with the ATLAS Detector at the Large Hadron Collider written by Chang Wei Loh 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 Searches for Heavy Charged Long Lived Particles with the ATLAS Detector written by Michael Adersberger and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Particle Physics Reference Library written by Christian W. Fabjan and published by Springer Nature. This book was released on 2020 with total page 1083 pages. Available in PDF, EPUB and Kindle. Book excerpt: This second open access volume of the handbook series deals with detectors, large experimental facilities and data handling, both for accelerator and non-accelerator based experiments. It also covers applications in medicine and life sciences. A joint CERN-Springer initiative, the "Particle Physics Reference Library" provides revised and updated contributions based on previously published material in the well-known Landolt-Boernstein series on particle physics, accelerators and detectors (volumes 21A, B1,B2,C), which took stock of the field approximately one decade ago. Central to this new initiative is publication under full open access
Download or read book Pattern Recognition Tracking and Vertex Reconstruction in Particle Detectors written by Rudolf Frühwirth and published by Springer Nature. This book was released on 2021 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt: This open access book is a comprehensive review of the methods and algorithms that are used in the reconstruction of events recorded by past, running and planned experiments at particle accelerators such as the LHC, SuperKEKB and FAIR. The main topics are pattern recognition for track and vertex finding, solving the equations of motion by analytical or numerical methods, treatment of material effects such as multiple Coulomb scattering and energy loss, and the estimation of track and vertex parameters by statistical algorithms. The material covers both established methods and recent developments in these fields and illustrates them by outlining exemplary solutions developed by selected experiments. The clear presentation enables readers to easily implement the material in a high-level programming language. It also highlights software solutions that are in the public domain whenever possible. It is a valuable resource for PhD students and researchers working on online or offline reconstruction for their experiments.
Download or read book Searches for Long lived Particles with the ATLAS Experiment written by and published by . This book was released on 2014 with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Search and Discovery of the Higgs Boson written by Luis Roberto Flores Castillo and published by Morgan & Claypool Publishers. This book was released on 2016-01-01 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a general description of the search for and discovery of the Higgs boson (particle) at CERN’s Large Hadron Collider. The goal is to provide a relatively brief overview of the issues, instruments and techniques relevant for this search; written by a physicist who was directly involved. The Higgs boson mat be the one particle that was studied the most before its discovery and the story from postulation in 1964 to detection in 2012 is a fascinating one. The story is told here while detailing the fundamentals of particle physics.
Download or read book The Physics of the Dark Photon written by Marco Fabbrichesi and published by Springer Nature. This book was released on 2020-11-23 with total page 85 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is about the dark photon which is a new gauge boson whose existence has been conjectured. Due to its interaction with the ordinary, visible photon, such a particle can be experimentally detected via specific signatures. In this book, the authors review the physics of the dark photon from the theoretical and experimental point of view. They discuss the difference between the massive and the massless case, highlighting how the two phenomena arise from the same vector portal between the dark and the visible sector. A review of the cosmological and astrophysical observations is provided, together with the connection to dark matter physics. Then, a perspective on current and future experimental limits on the parameters of the massless and massive dark photon is given, as well as the related bounds on milli-charged fermions. The book is intended for graduate students and young researchers who are embarking on dark photon research, and offers them a clear and up-to-date introduction to the subject.
Download or read book Handbook of Particle Detection and Imaging written by Claus Grupen and published by Springer Science & Business Media. This book was released on 2012-01-08 with total page 1251 pages. Available in PDF, EPUB and Kindle. Book excerpt: The handbook centers on detection techniques in the field of particle physics, medical imaging and related subjects. It is structured into three parts. The first one is dealing with basic ideas of particle detectors, followed by applications of these devices in high energy physics and other fields. In the last part the large field of medical imaging using similar detection techniques is described. The different chapters of the book are written by world experts in their field. Clear instructions on the detection techniques and principles in terms of relevant operation parameters for scientists and graduate students are given.Detailed tables and diagrams will make this a very useful handbook for the application of these techniques in many different fields like physics, medicine, biology and other areas of natural science.
Download or read book Higgs Boson Decays into a Pair of Bottom Quarks written by Cecilia Tosciri and published by Springer Nature. This book was released on 2021-10-22 with total page 171 pages. Available in PDF, EPUB and Kindle. Book excerpt: The discovery in 2012 of the Higgs boson at the Large Hadron Collider (LHC) represents a milestone for the Standard Model (SM) of particle physics. Most of the SM Higgs production and decay rates have been measured at the LHC with increased precision. However, despite its experimental success, the SM is known to be only an effective manifestation of a more fundamental description of nature. The scientific research at the LHC is strongly focused on extending the SM by searching, directly or indirectly, for indications of New Physics. The extensive physics program requires increasingly advanced computational and algorithmic techniques. In the last decades, Machine Learning (ML) methods have made a prominent appearance in the field of particle physics, and promise to address many challenges faced by the LHC. This thesis presents the analysis that led to the observation of the SM Higgs boson decay into pairs of bottom quarks. The analysis exploits the production of a Higgs boson associated with a vector boson whose signatures enable efficient triggering and powerful background reduction. The main strategy to maximise the signal sensitivity is based on a multivariate approach. The analysis is performed on a dataset corresponding to a luminosity of 79.8/fb collected by the ATLAS experiment during Run-2 at a centre-of-mass energy of 13 TeV. An excess of events over the expected background is found with an observed (expected) significance of 4.9 (4.3) standard deviation. A combination with results from other \Hbb searches provides an observed (expected) significance of 5.4 (5.5). The corresponding ratio between the signal yield and the SM expectation is 1.01 +- 0.12 (stat.)+ 0.16-0.15(syst.). The 'observation' analysis was further extended to provide a finer interpretation of the V H(H → bb) signal measurement. The cross sections for the VH production times the H → bb branching ratio have been measured in exclusive regions of phase space. These measurements are used to search for possible deviations from the SM with an effective field theory approach, based on anomalous couplings of the Higgs boson. The results of the cross-section measurements, as well as the constraining of the operators that affect the couplings of the Higgs boson to the vector boson and the bottom quarks, have been documented and discussed in this thesis. This thesis also describes a novel technique for the fast simulation of the forward calorimeter response, based on similarity search methods. Such techniques constitute a branch of ML and include clustering and indexing methods that enable quick and efficient searches for vectors similar to each other. The new simulation approach provides optimal results in terms of detector resolution response and reduces the computational requirements of a standard particles simulation.
Download or read book Search for Long lived Particles Decaying Into Electron Or Photon Pairs with the D0 Detector written by and published by . This book was released on 2008 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this Letter we report on a search for long-lived particles that decay into final states with two electrons or photons. Such long-lived particles arise in a variety of theoretical models, like hidden valleys and supersymmetry with gauge-mediated breaking. By precisely reconstructing the direction of the electromagnetic shower we are able to probe much longer lifetimes than previously explored. We see no evidence of the existence of such long-lived particles and interpret this search as a quasi model-independent limit on their production cross section, as well as a limit on a long-lived fourth generation quark.
Download or read book Search for Heavy Long lived Particles in ATLAS written by Enrique Kajomovitz and published by . This book was released on 2012 with total page 82 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Electroweak Interactions and Unified Theories written by J. Thanh Van Tran and published by Atlantica Séguier Frontières. This book was released on 1988 with total page 616 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Particle Physics at the Tercentenary of Mikhail Lomonosov written by Moskovskiĭ gosudarstvennyĭ universitet im. M.V. Lomonosova and published by World Scientific. This book was released on 2013 with total page 481 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume is devoted to a wide variety of investigations, both in theory and experiment, of particle physics such as electroweak theory, fundamental symmetries, tests of the Standard Model and beyond, neutrino and astroparticle physics, heavy quark physics, non-perturbative QCD, quantum gravity effects, and present and future accelerator physics.
Download or read book Particle Physics At The Tercentenary Of Mikhail Lomonosov Proceeding Of The Fifteenth Lomonosov Conference On Elementary Particle Physics written by Alexander I Studenikin and published by World Scientific. This book was released on 2012-11-27 with total page 481 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume is devoted to a wide variety of investigations, both in theory and experiment, of particle physics such as electroweak theory, fundamental symmetries, tests of the Standard Model and beyond, neutrino and astroparticle physics, heavy quark physics, non-perturbative QCD, quantum gravity effects, and present and future accelerator physics.
