Download or read book Search for the Standard Model Higgs boson produced in association with a pair of top quarks and decaying into a bb pair in the single lepton channel at s written by Matteo Mantoani and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis presents a search for Standard Model Higgs boson produced in association with top quark pairs, ttH. The analysis uses 13.2 fb-1 of pp collision data at √s = 13 TeV collected in 2015 and 2016 with the ATLAS detector at the LHC. The considered decay mode for the Higgs boson is H->bb and the single lepton decay channel (electron or muon) for the tt pair. The sensitivity of this channel is improved by an event categorisation according to the jet multiplicity and the number of jets containing a b-hadron decay. Multivariate techniques are used to distinguish the signa...
Download or read book Search for the Standard Model Higgs Boson Produced in Association with a Pair of Top Quarks and Decaying Into a Bb pair in the Single Lepton Channel at Sqrt s written by Leonid Serkin and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis focuses on the search for the Standard Model Higgs boson produced in association with a pair of top quarks, ttH, using 20.3 fb-1 of pp collision data at sqrt{s} = 8 TeV, collected with the ATLAS detector at the Large Hadron Collider during 2012. The search is designed for the H -> bb decay mode and is performed in the single lepton channel, characterised by an isolated electron or muon, missing transverse energy and at least four jets. In order to improve the sensitivity of the search, events are categorised according to their jet and b-tagged jet multiplicities into nine analys...
Download or read book Search for the Standard Model Higgs Boson Produced in Association with a Pair of Top Quarks and Decaying Into a Bb pair in the Single Lepton Channel at s written by Leonid Serkin and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Beauty ful Boson written by Giulia Di Gregorio and published by Springer Nature. This book was released on 2023-01-01 with total page 229 pages. Available in PDF, EPUB and Kindle. Book excerpt: The analysis described in this thesis is the search for the Higgs boson, decaying into bb pair, in the associated production with a vector boson, in the extreme Higgs boson transverse momentum region where the Higgs boson is reconstructed using the large-R jet technique. The use of the large-R jets allows to add a part of the phase space unexplored so far, which is particularly sensitive to possible new physics. The analysed data have been collected at LHC by the ATLAS detector between 2015 and 2018 at a centre-of-mass energy of √s = 13 TeV. The same dataset has been used to perform the differential pp → ZH and pp → WH cross-section measurements used to extract the information on the Higgs couplings and to put limits on Beyond the Standard Model effects. Furthermore the analysis has been re-used to perform a cross-section measurement of the diboson ZZ and WZ processes because the diboson and the Higgs processes have a similar topology. For the first time the ZZ(bb) and WZ(bb) cross-sections are measured at √s = 13 TeV and the observed cross-section measurements are consistent with the Standard Model predictions.
Download or read book Phenomena Beyond the Standard Model What Do We Expect for New Physics to Look Like written by Roman Pasechnik and published by Frontiers Media SA. This book was released on 2020-09-03 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Particle Physics Reference Library written by Herwig Schopper and published by Springer Nature. This book was released on 2020 with total page 632 pages. Available in PDF, EPUB and Kindle. Book excerpt: This first open access volume of the handbook series contains articles on the standard model of particle physics, both from the theoretical and experimental perspective. It also covers related topics, such as heavy-ion physics, neutrino physics and searches for new physics beyond the standard model. 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 Search for the Standard Model Higgs Boson Produced in Association with Tt and Decaying Into Bb at 8 TeV with the ATLAS Detector Using the Matrix Element Method written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A search for the Standard Model Higgs boson produced in association with a pair of top quarks (ttH) is presented. The analysis uses 20.3 fb-1 of pp collision data at √s = 8 TeV, collected with the ATLAS detector at the Large Hadron Collider during 2012. The search is designed for the H → bb decay mode and is performed in the single lepton (electrons or muons) decay channel of the top quark pair. In order to improve the sensitivity of the search, events are categorised according to their jet and b-tagged jet multiplicities into nine different analysis regions. A matrix element method is deve...
Download or read book Inclusive b Jet Production in Proton Proton Collisions written by Patrick L.S. Connor and published by Springer Nature. This book was released on 2019-11-29 with total page 325 pages. Available in PDF, EPUB and Kindle. Book excerpt: ^ 74 GeV and |y| 2.4; the b jets must contain a B hadron. The measurement has significant statistics up to p T ∼ O(TeV). Advanced methods of unfolding are performed to extract the signal. It is found that fixed-order calculations with underlying event describe the measurement well.
Download or read book Discovery Of The Higgs Boson written by Aleandro Nisati and published by World Scientific. This book was released on 2016-08-26 with total page 470 pages. Available in PDF, EPUB and Kindle. Book excerpt: The recent observation of the Higgs boson has been hailed as the scientific discovery of the century and led to the 2013 Nobel Prize in physics. This book describes the detailed science behind the decades-long search for this elusive particle at the Large Electron Positron Collider at CERN and at the Tevatron at Fermilab and its subsequent discovery and characterization at the Large Hadron Collider at CERN. Written by physicists who played leading roles in this epic search and discovery, this book is an authoritative and pedagogical exposition of the portrait of the Higgs boson that has emerged from a large number of experimental measurements. As the first of its kind, this book should be of interest to graduate students and researchers in particle physics.
Download or read book Search for the Standard Higgs Boson Produced in Association with a Pair of Top Quark in the Multi leptons Channel in the CMS Experiment written by Xavier Coubez and published by . This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The discovery in 2012 of the last elementary particle predicted by the Standard Model, the Higgs boson, has opened a new era in particle physics. One of the objectives now is to probe the coupling of the Higgs boson to other particles in order to confirm the validity of the model. The work of this thesis focused initially on the identification of jets coming from b quark at trigger level. The goal is to allow for the selection of one thousand events among the forty million produced every second at the LHC, by identifiying objects present in the final states of interesting physics processes such as the associated production of a Higgs boson decaying in a pair of b quark with a Z boson decaying into undetected neutrinos. The work then moved to the study of the coupling of the Higgs boson to the quark top, most massive particle in the Standard Model. After a study of one of the important background of the associated production of the Higgs boson and a top quark pair, a new method called matrix element method has been used to improve the discrimination between signal and background. This analysis has led to the first experimental evidence of coupling between the Higgs boson and the top quark.
Download or read book The Higgs Boson Produced With Top Quarks in Fully Hadronic Signatures written by Daniel Salerno and published by Springer Nature. This book was released on 2019-10-25 with total page 207 pages. Available in PDF, EPUB and Kindle. Book excerpt: The work presented in this PhD dissertation is the first search at CMS for Higgs bosons produced in association with top quarks (ttH) in a final state consisting of only jets. The results presented in this book uncover a new class of ttH events that will help us elucidate our understanding of the Yukawa sector interactions between the Higgs boson and the top quark. Despite this being the most common decay signature for ttH, a large contamination of SM backgrounds makes it the most challenging for extracting a signal from data. The PhD thesis presents many sophisticated tools and techniques that were developed in order to overcome these challenges. These tools pave the way for future analyses to investigate other standard model and beyond-standard model physics.
Download or read book Search for tt H Production in the H bb Decay Channel written by Marcel Rieger and published by Springer Nature. This book was released on 2021-02-25 with total page 217 pages. Available in PDF, EPUB and Kindle. Book excerpt: In 1964, a mechanism explaining the origin of particle masses was proposed by Robert Brout, François Englert, and Peter W. Higgs. 48 years later, in 2012, the so-called Higgs boson was discovered in proton-proton collisions recorded by experiments at the LHC. Since then, its ability to interact with quarks remained experimentally unconfirmed. This book presents a search for Higgs bosons produced in association with top quarks tt̄H in data recorded with the CMS detector in 2016. It focuses on Higgs boson decays into bottom quarks H → bb̅ and top quark pair decays involving at least one lepton. In this analysis, a multiclass classification approach using deep learning techniques was applied for the first time. In light of the dominant background contribution from tt̄ production, the developed method proved to achieve superior sensitivity with respect to existing techniques. In combination with searches in different decay channels, the presented work contributed to the first observations of tt̄H production and H → bb̅ decays.
Download or read book Search for the Standard Model Higgs Boson Produced in Association with Top Quarks in the Lepton Plus Jets Channel written by Sean C. Flowers and published by . This book was released on 2017 with total page 109 pages. Available in PDF, EPUB and Kindle. Book excerpt: Results for the search of a Higgs boson decaying to a bottom quark-antiquark pair produced with a top quark-antiquark pair (t ̄tH) in the lepton plus jets channel in proton-proton collisions at a center-of-mass energy of √ s = 13 TeV are presented. The data used corresponds to an integrated luminosity of 12.9 fb−1 recorded with the CMS experiment in 2016. To increase the sensitivity of the search, selected events are categorized by number of jets and number of b-tagged jets resulting in different expected signal and background rates. For each category two multivariate techniques are combined to separate the signal and background events. A machine learning process called a boosted decision tree (BDT) is trained on the two types of classes of events and then split into high and low purity based on the output. The physics motivated matrix element method (MEM) is applied to the BDT output to obtain the final two dimensional discriminator. The result is presented in terms of the t ̄tH signal strength modifier μ, the ratio of the observed t ̄tH production cross section relative to the expected cross section based on a 125 GeV Standard Model Higgs boson. A combined fit of the final discriminant in all categories of the lepton plus jets channel results an observed (expected) upper limit of μ
Download or read book The God Particle written by Leon M. Lederman and published by Houghton Mifflin Harcourt. This book was released on 2006 with total page 452 pages. Available in PDF, EPUB and Kindle. Book excerpt: A fascinating tour of particle physics from Nobel Prize winner Leon Lederman. At the root of particle physics is an invincible sense of curiosity. Leon Lederman embraces this spirit of inquiry as he moves from the Greeks' earliest scientific observations to Einstein and beyond to chart this unique arm of scientific study. His survey concludes with the Higgs boson, nicknamed the God Particle, which scientists hypothesize will help unlock the last secrets of the subatomic universe, quarks and all--it's the dogged pursuit of this almost mystical entity that inspires Lederman's witty and accessible history.
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 the Standard Model Higgs Boson Produced in Association with Top Quarks and Decaying Into a B B Pair in P P Collisions at S written by Felix Bührer 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 Search for a Standard Model Higgs Boson Produced in Association with a Top quark Pair and Decaying to Bottom Quarks Using a Matrix Element Method written by and published by . This book was released on 2015 with total page 41 pages. Available in PDF, EPUB and Kindle. Book excerpt:
