Download or read book Optimizing the Search for Excited Bosons W in Dijet Angular Distributions for the ATLAS Experiment written by Ayra Shahrooz Afshari and published by . This book was released on 2013 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Search for New Phenomena in Dijet Angular Distributions Measured with the ATLAS Detector in Proton proton Collisons at s written by and published by . This book was released on 2013 with total page 161 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Search for New Phenomena in Dijet Mass and Angular Distributions from pp Collisions at sqrt s written by and published by . This book was released on 2016 with total page 21 pages. Available in PDF, EPUB and Kindle. Book excerpt: This Letter describes a model-agnostic search for pairs of jets (dijets) produced by resonant and non-resonant phenomena beyond the Standard Model in 3.6 fb-1 of proton–proton collisions with a centre-of-mass energy of √s = 13 TeV recorded by the ATLAS detector at the Large Hadron Collider. The distribution of the invariant mass of the two leading jets is examined for local excesses above a data-derived estimate of the smoothly falling prediction of the Standard Model. The data are also compared to a Monte Carlo simulation of Standard Model angular distributions derived from the rapidity of the two jets. No evidence of anomalous phenomena is observed in the data, which are used to exclude, at 95% CL, quantum black holes with threshold masses below 8.3 TeV, 8.1 TeV, or 5.1 TeV5.1 TeV in three different benchmark scenarios; resonance masses below 5.2 TeV for excited quarks, 2.6 TeV in a W' model, a range of masses starting from mZ' = 1.5 TeV and couplings from gq = 0.2 in a Z' model; and contact interactions with a compositeness scale below 12.0 TeV and 17.5 TeV respectively for destructive and constructive interference between the new interaction and QCD processes. These results significantly extend the ATLAS limits obtained from 8 TeV data. As a result, gaussian-shaped contributions to the mass distribution are also excluded if the effective cross-section exceeds values ranging from approximately 50–300 fb for masses below 2 TeV to 2–20 fb for masses above 4 TeV.
Download or read book The Standard Theory of Particle Physics written by Luciano Maiani and published by World Scientific Publishing Company. This book was released on 2016-08-25 with total page 483 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book gives a quite complete and up-to-date picture of the Standard Theory with an historical perspective, with a collection of articles written by some of the protagonists of present particle physics. The theoretical developments are described together with the most up-to-date experimental tests, including the discovery of the Higgs Boson and the measurement of its mass as well as the most precise measurements of the top mass, giving the reader a complete description of our present understanding of particle physics.
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 LHC Physics written by T. Binoth and published by CRC Press. This book was released on 2012-04-25 with total page 415 pages. Available in PDF, EPUB and Kindle. Book excerpt: Exploring the phenomenology of the Large Hadron Collider (LHC) at CERN, LHC Physics focuses on the first years of data collected at the LHC as well as the experimental and theoretical tools involved. It discusses a broad spectrum of experimental and theoretical activity in particle physics, from the searches for the Higgs boson and physics beyond the Standard Model to studies of quantum chromodynamics, the B-physics sector, and the properties of dense hadronic matter in heavy-ion collisions. Covering the topics in a pedagogical manner, the book introduces the theoretical and phenomenological framework of hadron collisions and presents the current theoretical models of frontier physics. It offers overviews of the main detector components, the initial calibration procedures, and search strategies. The authors also provide explicit examples of physics analyses drawn from the recently shut down Tevatron. In the coming years, or perhaps even sooner, the LHC experiments may reveal the Higgs boson and offer insight beyond the Standard Model. Written by some of the most prominent and active researchers in particle physics, this volume equips new physicists with the theory and tools needed to understand the various LHC experiments and prepares them to make future contributions to the field.
Download or read book Quantum Black Holes written by Xavier Calmet and published by Springer Science & Business Media. This book was released on 2013-11-22 with total page 112 pages. Available in PDF, EPUB and Kindle. Book excerpt: Written by foremost experts, this short book gives a clear description of the physics of quantum black holes. The reader will learn about quantum black holes in four and higher dimensions, primordial black holes, the production of black holes in high energy particle collisions, Hawking radiation, black holes in models of low scale quantum gravity and quantum gravitational aspects of black holes.
Download or read book The Large Hadron Collider written by Lyndon R. Evans and published by EPFL Press. This book was released on 2009-01-01 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt: Describes the technology and engineering of the Large Hadron collider (LHC), one of the greatest scientific marvels of this young 21st century. This book traces the feat of its construction, written by the head scientists involved, placed into the context of the scientific goals and principles.
Download or read book The Large Hadron Collider written by Lyndon Evans and published by . This book was released on 2018 with total page 305 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 Experimental Particle Physics written by Deepak Kar and published by Programme: Iop Expanding Physi. This book was released on 2019-08-29 with total page 175 pages. Available in PDF, EPUB and Kindle. Book excerpt: Experimental Particle Physics is written for advanced undergraduate or beginning postgraduate students starting data analysis in experimental particle physics at the Large Hadron Collider (LHC) at CERN. Assuming only a basic knowledge of quantum mechanics and special relativity, the text reviews the current state of affairs in particle physics, before comprehensively introducing all the ingredients that go into an analysis.
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 Looking Inside Jets written by Simone Marzani and published by Springer. This book was released on 2019-05-11 with total page 205 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Astroparticle Particle and Space Physics Detectors and Medical Physics Applications written by Michele Barone and published by World Scientific. This book was released on 2006 with total page 1162 pages. Available in PDF, EPUB and Kindle. Book excerpt: The exploration of the subnuclear world is done through increasingly complex experiments covering a wide range of energies and in a large variety of environments ? from particle accelerators, underground detectors to satellites and space laboratories. For these research programs to succeed, novel techniques, new materials and new instrumentation need to be used in detectors, often on a large scale. Hence, particle physics is at the forefront of technological advancement and leads to numerous applications. Among these, medical applications have a particular importance due to the health and social benefits they bring. This volume reviews the advances made in all technological aspects of current experiments in the field.
Download or read book Statistics for Nuclear and Particle Physicists written by Louis Lyons and published by Cambridge University Press. This book was released on 1989-04-06 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book, written by a non-statistician for non-statisticians, emphasises the practical approach to those problems in statistics which arise regularly in data analysis situations in nuclear and high-energy physics experiments. Rather than concentrating on formal proofs of theorems, an abundant use of simple examples illustrates the general ideas which are presented, showing the reader how to obtain the maximum information from the data in the simplest manner. Possible difficulties with the various techniques, and pitfalls to be avoided, are also discussed. Based on a series of lectures given by the author to both students and staff at Oxford, this common-sense approach to statistics will enable nuclear physicists to understand better how to do justice to their data in both analysis and interpretation.
Download or read book Physics at the Terascale written by Ian Brock and published by John Wiley & Sons. This book was released on 2011-05-04 with total page 437 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Measurement of Higgs Boson Production Cross Sections in the Diphoton Channel written by Ahmed Tarek Abouelfadl Mohamed and published by Springer. This book was released on 2021-01-06 with total page 305 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis presents the measurement of the Higgs boson cross section in the diphoton decay channel. The measurement relies on proton-proton collision data at a center-of-mass energy √s = 13 TeV recorded by the ATLAS experiment at the Large Hadron Collider (LHC). The collected data correspond to the full Run-2 dataset with an integrated luminosity of 139 fb-1. The measured cross sections are used to constrain anomalous Higgs boson interactions in the Effective Field Theory (EFT) framework. The results presented in this thesis represent a reduction by a factor 2 of the different photon and jet energy scale and resolution systematic uncertainties with respect to the previous ATLAS publication. The thesis details the calibration of electron and photon energies in ATLAS, in particular the measurement of the presampler energy scale and the estimation of its systematic uncertainty. This calibration was used to perform a measurement of the Higgs boson mass in the H → γγ and H → 4l channels using the 36 fb−1 dataset.
