Download or read book Search for the Lepton Flavor Violating Decay math Display written by and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We use the ATLAS detector at the Large Hadron Collider to search for the lepton flavor violating process Z→e[mu] in pp collisions using 20.3 fb-1 of data collected at √s=8 TeV. An enhancement in the e[mu] invariant mass spectrum is searched for at the Z-boson mass. The number of Z bosons produced in the data sample is estimated using events of similar topology, Z→ee and [mu][mu], significantly reducing the systematic uncertainty in the measurement. In conclusion, there is no evidence of an enhancement at the Z-boson mass, resulting in an upper limit on the branching fraction, B(Z→e[mu])
Download or read book Search for the Lepton Flavor Violating Decay Z Implies Epsilon Mu with the ATLAS Detector written by D. T. Pignotti and published by . This book was released on 2014 with total page 85 pages. Available in PDF, EPUB and Kindle. Book excerpt: The ATLAS detector at the Large Hadron Collider is used to search for the lepton flavor violating process Z -> eμ in pp collisions using 20.3 fb^(-1) of data collected at sqrt(s)= 8 TeV. An enhancement in the eμ invariant mass spectrum is searched for at the Z boson mass. The number of Z bosons produced in the data sample is estimated using events of similar topology, Z -> ee and μμ, significantly reducing the systematic uncertainty in the measurement. There is no evidence of an enhancement at the Z boson mass, resulting in an upper limit on the branching fraction, B(Z -> eμ)
Download or read book Search for Charged lepton flavour Violation in Z boson Decays with the ATLAS Detector written by ATLAS Collaboration CERN and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Search for Lepton flavor VViolation in Z boson Decays with tau Leptons with the ATLAS Detector written by ATLAS Collaboration CERN and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Search for the Lepton flavor violating Decay K0L mu e written by Philip Lincoln Melese and published by . This book was released on 1988 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Search for Lepton Flavour Violation in Z tau Mu Decays at Sqrt s written by Sara Svendsen and published by . This book was released on 2017 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Probing Lepton Flavour Violation Via Neutrinoless tau 2 mu Decays with the ATLAS Detector written by and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This article presents the sensitivity of the ATLAS experiment to the lepton-flavour-violating decays of [tau]2![mu]. A method utilising the production of [tau] leptons via W2!tau][nu] decays is used. This method is applied to the sample of 20.3 fb-1 of pp collision data at a centre-of-mass energy of 8 TeV collected by the ATLAS experiment at the LHC in 2012. Lastly, no event is observed passing the selection criteria, and the observed (expected) upper limit on the [tau] lepton branching fraction into three muons, Br([tau]2![mu]), is 3.76×10-7 (3.94×10-7) at 90 % confidence level.
Download or read book Search for Lepton Flavor Violation in the Decay Tau to Mu Gamma written by and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A search for the nonconservation of lepton flavor number in the decay?{sup {+-}} →?{sup {+-}}? has been performed using 2.07 x 108 ee− →?+?− events produced at a center-of-mass energy near 10.58 GeV with the BABAR detector at the PEP-II storage ring. We find no evidence for a signal and set an upper limit on the branching ratio of?(?{sup {+-}} →?{sup {+-}}?)
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 The Composite Nambu Goldstone Higgs written by Giuliano Panico and published by Springer. This book was released on 2015-11-17 with total page 325 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Hierarchy Problem is arguably the most important guiding principle concerning the extension to high-energy scales of the Standard Model (SM) of Fundamental Interactions. Every scenario for addressing this issue unavoidably predicts new physics in the TeV energy range, which is currently being probed directly by the LHC experimental program. Among the possible solutions to the Hierarchy Problem, the scenario of a composite Higgs boson is a very simple idea and a rather plausible picture has emerged over the years by combining the following ingredients: First, the Higgs must be a (pseudo-) Nambu-Goldstone boson, rather than a generic hadron of the new strong sector. Second, through the so-called ‘partial compositeness’, SM particles mix with strong sector resonances with suitable quantum numbers, so that they become a linear combination of elementary and composite degrees of freedom. Recently, general descriptions of the Composite Higgs Scenario were developed which successfully capture the relevant features of this theoretical framework in a largely model-independent way. The present book provides a concise and illustrative introduction to the subject for a broad audience of graduate students and non-specialist researchers in the fields of particle, nuclear and gravitational physics.
Download or read book New Physics In B Decays written by Sheldon Stone and published by World Scientific. This book was released on 2022-04-07 with total page 232 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Standard Model (SM) of particle physics has withstood thus far every attempt by experimentalists to show that it does not describe data. We discuss the SM in some detail, focusing on the mechanism of fermion mixing, which represents one of its most intriguing aspects. We discuss how this mechanism can be tested in b-quark decays, and how b decays can be used to extract information on physics beyond the SM. We review experimental techniques in b physics, focusing on recent results and highlighting future prospects. Particular attention is devoted to recent results from b decays into a hadron, a lepton and an anti-lepton, that show discrepancies with the SM predictions — the so-called B-physics anomalies — whose statistical significance has been increasing steadily. We discuss these experiments in a detailed manner, and also provide theoretical interpretation of these results in terms of physics beyond the SM.
Download or read book Lectures on LHC Physics written by Tilman Plehn and published by Springer. This book was released on 2014-08-05 with total page 340 pages. Available in PDF, EPUB and Kindle. Book excerpt: With the discovery of the Higgs boson, the LHC experiments have closed the most important gap in our understanding of fundamental interactions, confirming that such interactions between elementary particles can be described by quantum field theory, more specifically by a renormalizable gauge theory. This theory is a priori valid for arbitrarily high energy scales and does not require an ultraviolet completion. Yet, when trying to apply the concrete knowledge of quantum field theory to actual LHC physics - in particular to the Higgs sector and certain regimes of QCD - one inevitably encounters an intricate maze of phenomenological know-how, common lore and other, often historically developed intuitions about what works and what doesn’t. These lectures cover three aspects to help understand LHC results in the Higgs sector and in searches for physics beyond the Standard Model: they discuss the many facets of Higgs physics, which is at the core of this significantly expanded second edition; then QCD, to the degree relevant for LHC measurements; as well as further standard phenomenological background knowledge. They are intended to serve as a brief but sufficiently detailed primer on LHC physics to enable graduate students and all newcomers to the field to find their way through the more advanced literature, and to help those starting to work in this very timely and exciting field of research. Advanced readers will benefit from this course-based text for their own lectures and seminars. .
Download or read book Strings Branes and Extra Dimensions written by Steven Scott Gubser and published by World Scientific. This book was released on 2004 with total page 872 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers some recent advances in string theory and extra dimensions. Intended mainly for advanced graduate students in theoretical physics, it presents a rare combination of formal and phenomenological topics, based on the annual lectures given at the School of the Theoretical Advanced Study Institute (2001) OCo a traditional event that brings together graduate students in high energy physics for an intensive course of advanced learning. The lecturers in the School are leaders in their fields. The first lecture, by E DOCOHoker and D Freedman, is a systematic introduction to the gaugeOCogravity correspondence, focusing in particular on correlation functions in the conformal case. The second, by L Dolan, provides an introduction to perturbative string theory, including recent advances on backgrounds involving Ramond-Ramond fluxes. The third, by S Gubser, explains some of the basic facts about special holonomy and its uses in string theory and M-theory. The fourth, by J Hewett, surveys the TeV phenomenology of theories with large extra dimensions. The fifth, by G Kane, presents the case for supersymmetry at the weak scale and some of its likely experimental consequences. The sixth, by A Liddle, surveys recent developments in cosmology, particularly with regard to recent measurements of the CMB and constraints on inflation. The seventh, by B Ovrut, presents the basic features of heterotic M-theory, including constructions that contain the Standard Model. The eighth, by K Rajagopal, explains the recent advances in understanding QCD at low temperatures and high densities in terms of color superconductivity. The ninth, by M Sher, summarizes grand unified theories and baryogenesis, including discussions of supersymmetry breaking and the Standard Model Higgs mechanism. The tenth, by M Spiropulu, describes collider physics, from a survey of current and future machines to examples of data analyses relevant to theories beyond the Standard Model. The eleventh, by M Strassler, is an introduction to supersymmetric gauge theory, focusing on Wilsonian renormalization and analogies between three- and four-dimensional theories. The twelfth, by W Taylor and B Zwiebach, introduces string field theory and discusses recent advances in understanding open string tachyon condensation. The thirteenth, by D Waldram, discusses explicit model building in heterotic M-theory, emphasizing the role of the E8 gauge fields. The written presentation of these lectures is detailed yet straightforward, and they will be of use to both students and experienced researchers in high-energy theoretical physics for years to come. The proceedings have been selected for coverage in: . OCo Index to Scientific & Technical Proceedings (ISTP CDROM version / ISI Proceedings). OCo CC Proceedings OCo Engineering & Physical Sciences."
Download or read book Studies of CP Violation in Charmless Three Body b Hadron Decays written by Daniel O'Hanlon and published by Springer. This book was released on 2018-11-02 with total page 215 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book highlights two essential analyses of data collected during the LHCb experiment, based on the Large Hadron Collider at CERN. The first comprises the first observation and studies of matter-antimatter asymmetries in two three-body b-baryon decays, paving the way for more precise measurements of the relatively unknown decay properties of b-baryon decays. The second is an analysis of a charged B meson decay to three charged pions, where previously large matter-antimatter asymmetries were observed in a model-independent analysis. Here a model of the decay amplitude is constructed using the unitarity-conserving ‘K-matrix’ model for the scalar contributions, so as to gain an understanding of how the previously observed matter-antimatter asymmetries arise; further, the model’s construction yields the most precise and comprehensive study of this decay mode to date.
Download or read book Statistical Problems in Particle Physics Astrophysics and Cosmology written by Louis Lyons and published by Imperial College Press. This book was released on 2006 with total page 326 pages. Available in PDF, EPUB and Kindle. Book excerpt: These proceedings comprise current statistical issues in analyzing data in particle physics, astrophysics and cosmology, as discussed at the PHYSTAT05 conference in Oxford. This is a continuation of the popular PHYSTAT series; previous meetings were held at CERN (2000), Fermilab (2000), Durham (2002) and Stanford (2003).In-depth discussions on topical issues are presented by leading statisticians and research workers in their relevant fields. Included are invited reviews and contributed research papers presenting the latest, state-of-the-art techniques.
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 Astroparticle Physics written by Claus Grupen and published by Springer Nature. This book was released on 2020-01-27 with total page 616 pages. Available in PDF, EPUB and Kindle. Book excerpt: Describes the branch of astronomy in which processes in the universe are investigated with experimental methods employed in particle-physics experiments. After a historical introduction the basics of elementary particles, Explains particle interactions and the relevant detection techniques, while modern aspects of astroparticle physics are described in a chapter on cosmology. Provides an orientation in the field of astroparticle physics that many beginners might seek and appreciate because the underlying physics fundamentals are presented with little mathematics, and the results are illustrated by many diagrams. Readers have a chance to enter this field of astronomy with a book that closes the gap between expert and popular level.
