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Search For Long Lived Neutral Particles Decaying To Quark Antiquark Pairs In Proton Proton Collisions At U221as
Download Search For Long Lived Neutral Particles Decaying To Quark Antiquark Pairs In Proton Proton Collisions At U221as full books in PDF, epub, and Kindle. Read online Search For Long Lived Neutral Particles Decaying To Quark Antiquark Pairs In Proton Proton Collisions At U221as ebook anywhere anytime directly on your device. Fast Download speed and no annoying ads. We cannot guarantee that every ebooks is available!
Book Synopsis Heavy Neutral Particle Decays to Tau Pairs by : Michail Bachtis
Download or read book Heavy Neutral Particle Decays to Tau Pairs written by Michail Bachtis and published by Springer Science & Business Media. This book was released on 2013-12-13 with total page 161 pages. Available in PDF, EPUB and Kindle. Book excerpt: The work presented in this thesis spans a wide range of experimental particle physics subjects, starting from level-1 trigger electronics to the final results of the search for Higgs boson decay and to tau lepton pairs. The thesis describes an innovative reconstruction algorithm for tau decays and details how it was instrumental in providing a measurement of Z decay to tau lepton pairs. The reliability of the analysis is fully established by this measurement before the Higgs boson decay to tau lepton pairs is considered. The work described here continues to serve as a model for analysing CMS Higgs to tau leptons measurements.
Book Synopsis Search for Flavor-Changing Neutral Current Top Quark Decays t → Hq, with H → bb̅ , in pp Collisions at √s = 8 TeV with the ATLAS Detector by : Shota Tsiskaridze
Download or read book Search for Flavor-Changing Neutral Current Top Quark Decays t → Hq, with H → bb̅ , in pp Collisions at √s = 8 TeV with the ATLAS Detector written by Shota Tsiskaridze and published by Springer. This book was released on 2017-08-02 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt: This PhD thesis focuses on the search for flavor-changing neutral currents in the decay of a top quark to an up-type quark (q = u, c) and the Standard Model Higgs boson, where the Higgs boson decays to bb. Further, the thesis presents the combination of this search for top quark pair events with other ATLAS searches – in the course of which the most restrictive bounds to date on tqH interactions were obtained. Following on from the discovery of the Higgs boson, it is particularly important to measure the Yukawa couplings of the Standard Model fermions; these parameters may provide crucial insights to help solve the flavor puzzle and may help reveal the presence of new physics before it is directly observed in experiments.
Book Synopsis Search for the Decay K_L → π^0\nu\bar{\nu} at the J-PARC KOTO Experiment by : Kota Nakagiri
Download or read book Search for the Decay K_L → π^0\nu\bar{\nu} at the J-PARC KOTO Experiment written by Kota Nakagiri and published by Springer Nature. This book was released on 2020-08-20 with total page 151 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book reports on a new result from the KL→π0νν search at the J-PARC KOTO experiment, which sets an upper limit of 3×10-9 for the branching fraction of the decay at the 90% confidence level, improving the previous best limit by an order of magnitude. To explain the matter–antimatter asymmetry in the universe, still unknown new physics beyond the standard model (SM) that breaks CP symmetry is necessary. The rare decay of a long-lived neutral K meson, KL→π0νν, is a CP-violating decay. It is an excellent probe to search for new physics because new physics can contribute to the decay and change its branching fraction, while the SM is as small as 3×10-11. However, it is extremely difficult to search for because all of the decay products are neutral and two neutrinos are undetectable. The KL→π0νν signal is identified by measuring two photons from a π0 with a calorimeter and confirming the absence of any other detectable particles with hermetic veto counters. The book contributes to the analysis of neutron-induced backgrounds which were the dominant background sources in the search. For the background caused by two consecutive hadronic showers in the calorimeter due to a neutron, the author evaluated the background yield using a data-driven approach. For another background caused by an η meson production—η decays two photons—by a neutron that hits a veto counter near the calorimeter, the author developed an original analysis technique to reduce it. The book also contributes to the analysis of the normalization modes (KL→3π0, KL→2π0, KL→2γ) to measure KL yield, the estimation of the signal acceptance based on a simulation, and the evaluation of the trigger efficiency. As a result, significant improvements in the measurement were achieved, and this is an important step in the continuing higher sensitivity search, which can reach new physics with the energy scales up to O(100-1000 TeV).
Book Synopsis Searches for Dijet Resonances by : Lydia Audrey Beresford
Download or read book Searches for Dijet Resonances written by Lydia Audrey Beresford and published by Springer. This book was released on 2018-09-04 with total page 175 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book addresses one of the most intriguing mysteries of our universe: the nature of dark matter. The results presented here mark a significant and substantial contribution to the search for new physics, in particular for new particles that couple to dark matter. The first analysis presented is a search for heavy new particles that decay into pairs of hadronic jets (dijets). This pioneering analysis explores unprecedented dijet invariant masses, reaching nearly 7 TeV, and sets constraints on several important new physics models. The two subsequent analyses focus on the difficult low dijet mass region, down to 200 GeV, and employ a novel technique to efficiently gather low-mass dijet events. The results of these analyses transcend the long-standing constraints on dark matter mediator particles set by several existing experiments.
Book Synopsis Search for Flavor-changing Neutral Current Top Quark Decays T—›Hq, with H—›bb, in Pp Collisions at √s by : Shota Tsiskaridze
Download or read book Search for Flavor-changing Neutral Current Top Quark Decays T—›Hq, with H—›bb, in Pp Collisions at √s written by Shota Tsiskaridze and published by . This book was released on 2016 with total page 232 pages. Available in PDF, EPUB and Kindle. Book excerpt: Esta tesis presenta la búsqueda de decaimientos del quark top, via corrientes neutras que cambian el sabor, a quarks tipo u (q = u; c) y a el bosón de Higgs del modelo estándar. El análisis busca eventos donde un quark top decae a Wb y el W decae en leptones, mientras que el otro quark top decae a Hq. El estudio se basa en colisiones protón-protón a una energía en el centro de masa de √ s = 8 TeV obtenidas en 2012 con el detector ATLAS del Large Hadron Collider del CERN, usando una muestra de 20.3 fb-1. Los datos corresponden a eventos con un electrón o muon aislado y al menos cuatro jets en el estado final. La búsqueda explota la alta multiplicidad de quarks b que caracterizan la señal, empleando un discriminante basado en la verosimilitud que utiliza las diferencias cinemáticas entre la señal y el fondo (el cual está dominado por eventos tt—›WbWb). No se observan eventos en exceso del fondo esperado. Los límites de un 95% de confianza para el proceso observado (esperado) son de 0.56% (0.42%) para t —›Hc y de 0.61% (0.64%) para t—›Hu. Los límites de esta búsqueda han sido combinados con las búsquedas en los canales con modos de decaimiento H—› y H—›WW*; tt , logrando mejorar significativamente la sensibilidad. Los límites de un 95% de confianza para la combinación observada (esperada) es de 0.46% (0.25%) para t—› Hc y 0.45% (0.29%) para t ! Hu respectivamente. Los límites correspondientes en el acoplamiento.
Download or read book Quark Matter written by Helmut Satz and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 354 pages. Available in PDF, EPUB and Kindle. Book excerpt: From the Editors Preface: "Quark Matter 1987 was attended by about 250 scientists, representing 75 research institutions around the world - the scientific community engaged in experimental and theoretical studies of high energy nuclear collisions. The central theme of the meeting was the possibility of achieving extreme energy densities in extended systems of strongly interacting matter - with the ultimate aim of creating in the laboratory a deconfined state of matter, a state in which quarks and gluons attain the active degrees of freedom. High energy accelerator beams and cosmic radiation projectiles provide the experimental tools for this endeavour; on the theoretical side, it is intimately connected to recent developments in the non-perturbative study of quantum chromodynamics. Phase transitions between hadronic matter and quark-gluon plasma are of basic interest also for our understanding of the dynamics of the early universe ... A very special feature of this Sixth Quark Matter Conference was the advent of the first experimental results from dedicated accelerator studies. These were conducted during 1986/87 at the AGS of Brookhaven National Laboratory ... and at the CERN SPS ... An intense discussion of these data formed the main activity of the meeting.
Book Synopsis Hidden Worlds by : Timothy Paul Smith
Download or read book Hidden Worlds written by Timothy Paul Smith and published by Princeton University Press. This book was released on 2005-03-27 with total page 193 pages. Available in PDF, EPUB and Kindle. Book excerpt: No one has ever seen a quark. Yet physicists seem to know quite a lot about the properties and behavior of these ubiquitous elementary particles. Here a top researcher introduces us to a fascinating but invisible realm that is part of our everyday life. Timothy Smith tells us what we know about quarks--and how we know it. Though the quarks that make science headlines are typically laboratory creations generated under extreme conditions, most quarks occur naturally. They reside in the protons and neutrons that make up almost all of the universe's known matter, from human DNA to distant nebulae, from books and tables to neutron stars. Smith explains what these quarks are, how they act, and why physicists believe in them sight unseen. How do quarks arrange themselves? What other combinations can nature make? How do quarks hold nuclei together? What else is happening in their hidden worlds? It turns out that these questions can be answered using a few simple principles, such as the old standby: opposites attract. With these few principles, Smith shows how quarks dance around each other and explains what physicists mean when they refer to "up" and "down" quarks and talk about a quark's color, flavor, and spin. Smith also explains how we know what we know about these oddly aloof particles, which are eternally confined inside larger particles. He explains how quark experiments are mounted and how massive accelerators, targets, and detectors work together to collect the data that scientists use to infer what quarks are up to. A nonmathematical tour of the quark world, this book is written for students, educators, and all who enjoy scientific exploration--whether they seek a taste of subnuclear physics or just wonder about nature on the smallest of scales.
Book Synopsis Extending the Limits in the Hunt for Long-lived Heavy Neutral Leptons with the ATLAS Experiment at the Large Hadron Collider at CERN by : Christian Appelt
Download or read book Extending the Limits in the Hunt for Long-lived Heavy Neutral Leptons with the ATLAS Experiment at the Large Hadron Collider at CERN written by Christian Appelt and published by . This book was released on 2024* with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Englische Version: A search for a long-lived, heavy neutral lepton ($\mathcal{N}$) in 139~fb$ {-1}$ of $\sqrt{s}=13$~TeV $pp$ collision data collected between 2015 and 2018 by the ATLAS detector at the Large Hadron Collider is presented. The $\mathcal{N}$ is assumed to be produced via $W \rightarrow \mathcal{N} \mu$ or $W \rightarrow \mathcal{N} e$ and decays into two charged leptons and a neutrino, forming a unique displaced vertex signature. A novel technique is used to reconstruct the $\mathcal{N}$ mass that discriminates between signal and background. No signal is observed, and limits are set on the squared mixing parameters of the $\mathcal{N}$ with the left-handed neutrino states for the $\mathcal{N}$ mass range $3$~GeV~$
Book Synopsis The Spin Structure of the Proton by : Steven D. Bass
Download or read book The Spin Structure of the Proton written by Steven D. Bass and published by World Scientific. This book was released on 2008 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt: One of the main challenges in nuclear and particle physics in the last 20 years has been to understand how the proton's spin is built up from its quark and gluon constituents. Quark models generally predict that about 60% of the proton's spin should be carried by the spin of the quarks inside, whereas high energy scattering experiments have shown that the quark spin contribution is small - only about 30%. This result has been the underlying motivation for about 1000 theoretical papers and a global program of dedicated spin experiments at BNL, CERN, DESY and Jefferson Laboratory to map the individual quark and gluon angular momentum contributions to the proton's spin, which are now yielding exciting results. This book gives an overview of the present status of the field: what is new in the data and what can be expected in the next few years. The emphasis is on the main physical ideas and the interpretation of spin data. The interface between QCD spin physics and the famous axial U(1) problem of QCD (eta and etaprime meson physics) is also highlighted. Book jacket.
Book Synopsis New Aspects of High-Energy Proton-Proton Collisions by : A. Ali
Download or read book New Aspects of High-Energy Proton-Proton Collisions written by A. Ali and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 437 pages. Available in PDF, EPUB and Kindle. Book excerpt: Articles focus on the planned European proton-proton collider, and concentrate on physics issues, rather than the more technical concerns addressed in the three previous workshops. The use of energies much higher than those of the American Superconducting Super Collider is featured. Topics include reviews of current projects, hadron collisions, lep
Book Synopsis Associated Production of W + Charm in 13 TeV Proton-Proton Collisions Measured with CMS and Determination of the Strange Quark Content of the Proton by : Svenja Karen Pflitsch
Download or read book Associated Production of W + Charm in 13 TeV Proton-Proton Collisions Measured with CMS and Determination of the Strange Quark Content of the Proton written by Svenja Karen Pflitsch and published by Springer Nature. This book was released on 2020-08-18 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt: The associated production of a W boson and a single charm quark (W+c) is the only process in proton-proton collisions that directly probes the strange quark content of the proton. In this thesis, W+charm production is measured in proton-proton collisions at the LHC at 13 TeV, as recorded by the Compact Muon Solenoid (CMS) experiment. The analysis focuses on the identification of W bosons in their leptonic decay to a muon and a neutrino and charm quarks are tagged via the full reconstruction of D*-Mesons. The measured cross sections of W+c production are used, in combination with other relevant CMS results and the most precise HERA DIS data, in a QCD analysis to determine the strange quark content of the proton. The resulting strange quark distribution and suppression, with respect to the other light sea quarks, are in good agreement with those obtained in neutrino scattering experiments and extend their kinematic reach.
Book Synopsis High Pt Physics at Hadron Colliders by : Dan Green
Download or read book High Pt Physics at Hadron Colliders written by Dan Green and published by Cambridge University Press. This book was released on 2005 with total page 280 pages. Available in PDF, EPUB and Kindle. Book excerpt: Publisher Description
Book Synopsis An Introduction to Quarks and Partons by : F. E. Close
Download or read book An Introduction to Quarks and Partons written by F. E. Close and published by . This book was released on 1979 with total page 500 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Proton-antiproton Collider Physics by : G. Altarelli
Download or read book Proton-antiproton Collider Physics written by G. Altarelli and published by World Scientific. This book was released on 1989 with total page 420 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume reviews the physics studied at the CERN proton-antiproton collider during its first phase of operation, from the first physics run in 1981 to the last one at the end of 1985.The volume consists of a series of review articles written by physicists who are actively involved with the collider research program. The first article describes the proton-antiproton collider facility itself, including the antiproton source and its principle of operation based on stochastic cooling.The subsequent six articles deal with the various physics subjects studied at the collider. Each article describes in detail the experimental results on a particular subject, and also provides the theoretical framework necessary for their interpretation. Finally the last two articles discuss the physics expectations from the improved collider (the so-called ACOL program, which has just started operation), and also from the next generation of ?supercolliders? which are being considered both in Europe and in the United States America.
Download or read book Quarks written by Harald Fritzsch and published by . This book was released on 1983-06-12 with total page 330 pages. Available in PDF, EPUB and Kindle. Book excerpt: Offers a non-technical introduction to particle physics, the subnuclear structure of the atom, and the research that led to the discovery of quarks - the basic components of matter.
Book Synopsis Spin Correlations in Tt Events from Pp Collisions by : Boris Lemmer
Download or read book Spin Correlations in Tt Events from Pp Collisions written by Boris Lemmer and published by . This book was released on 2015 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis introduces readers to the Standard Model, the top quark and its properties, before explaining the concept of spin correlation measurement. The first measurement of top quark spin correlations at the LHC in the lepton+jets decay channel is presented. As the heaviest elementary particle, the top quark plays an essential role in the Standard Model of elementary particle physics. In the case of top quarks being produced in pairs at hadron colliders, the Standard Model predicts their spins to be correlated. The degree of correlation depends on both the production mechanism and properties of the top quark. Any deviation from the Standard Model prediction can be an indicator for new physics phenomena. The thesis employs an advanced top quark reconstruction algorithm including dedicated identification of the up- and down-type quarks from the W boson decay.
Book Synopsis Gauge Theories, Massive Neutrinos and Proton Decay by :
Download or read book Gauge Theories, Massive Neutrinos and Proton Decay written by and published by Springer Science & Business Media. This book was released on 2013-12-01 with total page 387 pages. Available in PDF, EPUB and Kindle. Book excerpt: The following proceedings contains most of the contributions given at Orbis Scientiae 1981. As has become customary during the past few years, the organizers and moderators have attempted to strike a balance between reviews of the status of experimental and theoretical developments during the preceding year. We are very pleased that experimentalists representing the critical developments in new accelerator plans, neutrino oscillations, proton decay, and decay schemes of the upsilon, have seen fit to enlighten at first hand their theoretical colleagues. We believe that this interaction can be of great benefit to both groups. The reports of theorists on many of the key theoretical advances by the practitioners themselves is a particularly satisfying feature of this series of conferences and is a tribute to the care and wisdom of the session moderators. Although it has not been a customary editorial practice, we feel that it is particularly appropriate to point out that the 1981 recipient of the J. Robert Oppenheimer Memorial Prize was Professor Frederick Reines, of University of California, Irvine, for his pioneering experiments which first experimentally estab lished the existence of the neutrino. The flurry of activit- experimental and theoretical - generated by recent evidence for massive neutrinos is amply reflected in the contents of this volume. The enthusiasm and skill of Mrs. Helga S. Billings and Mrs. Susan L. Maxon in the organization and the running of the con ference, as well as in the preparation of these proceedings, is gratefully acknowledged.
