Search for Scalar Top Quarks and Higgsino-Like Neutralinos

Search for Scalar Top Quarks and Higgsino-Like Neutralinos

Author: Takuya Nobe

Publisher: Springer

Published: 2015-11-30

Total Pages: 229

ISBN-13: 9811000034

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This book reports a search for theoretically natural supersymmetry (SUSY) at the Large Hadron Collider (LHC). The data collected with the ATLAS detector in 2012 corresponding to 20 /fb of an integrated luminosity have been analyzed for stop pair production in proton–proton collisions at a center-of-mass energy of 8 TeV at the Large Hadron Collider (LHC) in the scenario of the higgsino-like neutralino. The author focuses on stop decaying into a bottom quark and chargino. In the scenario of the higgsino-like neutralino, the mass difference between charginos and neutralinos (Δm) is expected to be small, and observable final-state particles are likely to have low-momentum (soft). The author develops a dedicated analysis with a soft lepton as a probe of particles from chargino decay, which suppresses the large amount of backgrounds. As a result of the analysis, no significant SUSY signal is observed. The 95% confidence-level exclusion limits are set to masses of stop and neutralino assuming Δm = 20 GeV. The region with ΔM (the mass difference between stop and neutralino) 70 GeV is excluded for the first time at stop mass of less than 210 GeV. The author also excludes the signals with ΔM 120 GeV up to 600 GeV of stop mass with neutralino mass of less than 280 GeV. The author clearly shows very few remaining parameter spaces for light stop (e.g., topology of stop decay is extremely similar to the SM top quark) by combining his results and previous ATLAS analyses. His results provide a strong constraint to searches for new physics in the future.


Weak Scale Supersymmetry

Weak Scale Supersymmetry

Author: Howard Baer

Publisher: Cambridge University Press

Published: 2023-01-31

Total Pages: 557

ISBN-13: 1009289845

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This OA text develops the basic concepts of supersymmetry for experimental and phenomenological particle physicists and graduate students.


Lepton Dipole Moments

Lepton Dipole Moments

Author: B. Lee Roberts

Publisher: World Scientific

Published: 2010

Total Pages: 772

ISBN-13: 9814271845

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This book provides a self-contained description of the measurements of the magnetic dipole moments of the electron and muon, along with a discussion of the measurements of the fine structure constant, and the theory associated with magnetic and electric dipole moments. Also included are the searches for a permanent electric dipole moment of the electron, muon, neutron and atomic nuclei. The related topic of the transition moment for lepton flavor violating processes, such as neutrinoless muon or tauon decays, and the search for such processes are included as well. The papers, written by many of the leading authors in this field, cover both the experimental and theoretical aspects of these topics. Sample Chapter(s). Chapter 1: Historical Introduction to Electric and Mangnetic Moments (367 KB). Contents: Historical Introduction (B L Roberts); Electromagnetic Dipole Moments and New Physics (A Czarnecki & W J Marciano); Lepton g OCo 2 from 1947 to Present (T Kinoshita); Analytic QED Calculations of the Anomalous Magnetic Moment of the Electron (S Laporta & E Remiddi); Measurements of the Electron Magnetic Moment (G Gabrielse); Determining the Fine Structure Constant (G Gabrielse); Helium Fine Structure Theory for the Determination of (K Pachucki & J Sapirstein); Hadronic Vacuum Polarization and the Lepton Anomalous Magnetic Moments (M Davier); The Hadronic Light-by-Light Contribution to a, e (J Prades et al.); General Prescriptions for One-loop Contributions to a e, (K R Lynch); Measurement of the Muon ( g OCo 2) Value (J P Miller et al.); Muon ( g OCo 2) and Physics Beyond the Standard Model (D StAckinger); Probing CP Violation with Electric Dipole Moments (M Pospelov & A Ritz); The Electric Dipole Moment of the Electron (E D Commins & D DeMille); Neutron EDM Experiments (S K Lamoreaux & R Golub); Nuclear Electric Dipole Moments (W C Griffith et al.); EDM Measurements in Storage Rings (B L Roberts et al.); Models of Lepton Flavor Violation (Y Okada); Search for the Charged Lepton-Flavor-Violating Transition Moments l OaAE l OC (Y Kuno). Readership: Researchers and graduate students in particle physics, atomic physics and nuclear physics, as well as experts working in the field


Physics From Planck Scale To Electroweak Scale - Proceedings Of The Us-polish Workshop 1994

Physics From Planck Scale To Electroweak Scale - Proceedings Of The Us-polish Workshop 1994

Author: Pran Nath

Publisher: World Scientific

Published: 1995-04-28

Total Pages: 510

ISBN-13: 9814549517

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The Proceedings of the Workshop covers a broad range of subjects from low energy supersymmetry through supersymmetric grand unification to supergravity and superstring theories. Although the focus was mainly on theoretical problems and ideas, the present and future experimental searches of new particles were also discussed.


Cosmic Matter

Cosmic Matter

Author: Siegfried Röser

Publisher: John Wiley & Sons

Published: 2008-09-26

Total Pages: 426

ISBN-13: 3527623000

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This 20th volume in the series contains 16 invited reviews and highlight contributions presented during the 2007 International Scientific Conference of the German Astronomical Society on the topic of "Cosmic Matter", held in Würzburg, Germany. The papers published here discuss a wide range of hot topics, including cosmology, high-energy astrophysics, astroparticle physics gravitational waves, extragalactic and stellar astronomy -- together representing the roadmap for astroparticle physics in Europe.


Yet Another Introduction to Dark Matter

Yet Another Introduction to Dark Matter

Author: Martin Bauer

Publisher: Springer

Published: 2019-06-11

Total Pages: 183

ISBN-13: 3030162346

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Dark matter is a frequently discussed topic in contemporary particle physics. Written strictly in the language of particle physics and quantum field theory, these course-based lecture notes focus on a set of standard calculations that students need in order to understand weakly interacting dark matter candidates. After introducing some general features of these dark matter agents and their main competitors, the Higgs portal scalar and supersymmetric neutralinos are introduced as our default models. In turn, this serves as a basis for exploring four experimental aspects: the dark matter relic density extracted from the cosmic microwave background; indirect detection including the Fermi galactic center excess; direct detection; and collider searches. Alternative approaches, like an effective theory of dark matter and simplified models, naturally follow from the discussions of these four experimental directions.


Hunting the Faster than Light Tachyon, and Finding Three Unicorns and a Herd of Elephants

Hunting the Faster than Light Tachyon, and Finding Three Unicorns and a Herd of Elephants

Author: Robert Ehrlich

Publisher: CRC Press

Published: 2022-05-18

Total Pages: 213

ISBN-13: 1000587932

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In 1905, Albert Einstein declared speeds greater than light to be impossible. This book describes the author’s decades-long search for the hypothetical subatomic particles known as tachyons that violate this principle. This book is a scientific detective story. The crime is speeding—that is, the possible breaking of the cosmic speed limit, namely the speed of light, as stipulated by Einstein. This detective story is also a memoir written by a member of a band of "tachyon hunters." The author’s pursuit of tachyons has been met with skepticism from most physicists, who note correctly that no such superluminal particles have ever been surely observed and that there have been many false sightings. Nevertheless, considerable circumstantial evidence for tachyons has already been published and an ongoing experiment could decide the issue in the next few years. This book is written for the general reader, containing humor and eliminating jargon whenever possible, and will also be of interest to scientists. The hunt for the tachyon will fascinate all readers who approach the study of physics with curious and open minds.