Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 11
Book Description
Revisiting XENON100's Constraints (and Signals?) For Low-Mass Dark Matter
Author: Low-mass Dark Matter Search with the XENON100 Experiment
Author: Andrea TiseniPublisher:
ISBN: 9789462338432
Category :
Languages : en
Pages : 146
Book Description
"It is hypothesized that 26% of the mass and energy content of the universe consists of Dark Matter. The most promising Dark Matter candidates are Weakly Interacting Massive Particles (WIMP). If WIMPs are the Dark Matter particles, then they could be directly de-tected via their scattering off nuclei. The XENON100 experiment aims to detect the scattering of a WIMP with a xenon nucleus. This experiment is a xenon-based dual-phase (liquid-gas) Time Projection Chamber (TPC). The interaction of a particle in the TPC produces both scintillation photons and ionization electrons, which are both detected as light signals by photomultipliers. So far, the XENON100 experiment has not observed WIMPs, and exclusion limits have been produced. The data analysis relies on an accurate description of the backgrounds. In this thesis I present an analysis that assumes potentially unknown backgrounds to be present in the data. In this way, a WIMP exclusion limit without background subtraction is calculated with a minimum WIMP-nucleon cross section of 2.05 × 10-45 cm2 at a WIMP mass of 50 GeV. Furthermore, I developed a new method to enhance the sensitivity of the XENON100 experiment towards low-mass WIMPs using solely the ionization signal to calculate the recoil energy. Using this method, the sensitivity of the XENON100 experiment is improved by several orders of magnitude for WIMP masses below 7 GeV, excluding a WIMP-nucleon cross section of 1.4 × 10-41 cm2 at a WIMP mass of 6 GeV."--Samenvatting auteur.
Search for Low Mass Dark Matter with the XENON100 Experiment and Simulations for 1 Ton and 10 Ton Dark Matter Detectors
Author: Ethan Craig BrownThe Search for Dark Matter in XENON100 Using a Two-dimensional Profile Likelihood Analysis
Author: Kevin Joseph LungPublisher:
ISBN:
Category :
Languages : en
Pages : 169
Book Description
Direct dark matter detectors are currently probing the favored supersymmetric theoretical phase space for weakly interacting massive particles (WIMPs) as part of a larger electroweak sector particle search. The XENON100 detector has recently improved upon their world-best upper limits on WIMP-nucleon scattering cross sections from 2011 with new results presented in 2012, which have further ruled out much of the predicted regions for dark matter. In the low mass regime, the results shown so far have been conservative in addressing the claims of a WIMP detection by CoGeNT, DAMA and CRESSTII. This thesis discusses a different approach to analyzing the XENON100 data with a profile likelihood statistical method using the ionization channel to improve both energy reconstruction and energy resolution and probe the low WIMP mass region. A Monte Carlo simulation using a combination of detector geometry and underlying statistical features of signal production has been developed to determine the ionization yield, which has only a few direct measurements, and to model WIMP interactions as input to the statistical technique. The resulting profile likelihood analysis, which includes systematic uncertainties in the energy scales and background and signal models, has been able to improve the current upper limits by a factor of 10 in the low mass region (6-10 GeV/c2) and about a factor of 2 up to 50 GeV/c2. The discovery potential of the dataset is also studied, which has produced a 2.3[sigma] significance for a 7.5 GeV/c2 particle at a cross section of [sigma]_x-N =1.8 X 10−43 cm2 with a 95% confidence interval of [1.74 X 10−44,7.76 & times;10−43] cm2.
From the Fermi Scale to Cosmology
Author: Alberto SalvioPublisher: Frontiers Media SA
ISBN: 2889632059
Category :
Languages : en
Pages : 265
Book Description
Theory And Phenomenology Of Sparticles: An Account Of Four-dimensional N=1 Supersymmetry In High Energy Physics
Author: Manuel DreesPublisher: World Scientific
ISBN: 9814495344
Category : Science
Languages : en
Pages : 582
Book Description
Supersymmetry or SUSY, one of the most beautiful recent ideas of physics, predicts sparticles existing as superpartners of particles. This book gives a theoretical and phenomenological account of sparticles. Starting from a basic level, it provides a comprehensive, pedagogical and user-friendly treatment of the subject of four-dimensional N=1 supersymmetry as well as its observational aspects in high energy physics and cosmology. Part One of the book introduces the requisite formal theory, preceded by a discussion of the naturalness problem. Part Two describes the supersymmetrization of the Standard Model of particle interactions as well as the origin of soft supersymmetry breaking and how it can be mediated from higher energies. Search strategies for sparticles, supersymmetric Higgs bosons, nonminimal scenarios and cosmological implications are some of the other topics covered. Novel features of the book include a dictionary between two-component and four-component spinor notation, a step-by-step derivation of the nonrenormalization theorem, an extended discussion of supersymmetric renormalization group evolution, detailed analyses of minimal and nonminimal models with gravity (including anomaly) mediated and gauge mediated supersymmetry breaking as well as elaborate self-contained presentations of collider signals of sparticles plus supersymmetric Higgs bosons and of supersymmetric cosmology. Appendices list all Feynman rules for the vertices of the Minimal Supersymmetric Standard Model.
The Dark Matter Problem
Author: Robert H. SandersPublisher: Cambridge University Press
ISBN: 1139485733
Category : Science
Languages : en
Pages : 214
Book Description
Most astronomers and physicists now believe that the matter content of the Universe is dominated by dark matter: hypothetical particles which interact with normal matter primarily through the force of gravity. Though invisible to current direct detection methods, dark matter can explain a variety of astronomical observations. This book describes how this theory has developed over the past 75 years, and why it is now a central feature of extragalactic astronomy and cosmology. Current attempts to directly detect dark matter locally are discussed, together with the implications for particle physics. The author comments on the sociology of these developments, demonstrating how and why scientists work and interact. Modified Newtonian Dynamics (MOND), the leading alternative to this theory, is also presented. This fascinating overview will interest cosmologists, astronomers and particle physicists. Mathematics is kept to a minimum, so the book can be understood by non-specialists.
Stars as Laboratories for Fundamental Physics
Author: Georg G. RaffeltPublisher: University of Chicago Press
ISBN: 9780226702728
Category : Science
Languages : en
Pages : 692
Book Description
Much of what we know about neutrinos is revealed by astronomical observations, and the same applies to the axion, a conjectured new particle that is a favored candidate for the main component of the dark matter of the universe.
Perspectives on Supersymmetry II
Author: G. L. KanePublisher: World Scientific
ISBN: 9814307505
Category : Science
Languages : en
Pages : 604
Book Description
Supersymmetry is at an exciting stage of development. It extends the Standard Model of particle physics into a more powerful theory that both explains more and allows more questions to be addressed. Most importantly, it opens a window for studying and testing fundamental theories at the Planck scale. Experimentally we are finally entering the intensity and energy and sensitivity regions where superpartners and supersymmetric dark matter candidates are likely to be detected, and then studied. There has been progress in understanding the remarkable physics implications of supersymmetry, including the derivation of the Higgs mechanism, the unification of the Standard Model forces, cosmological connections such as a candidate for the cold dark matter of the universe and consequences for understanding the cosmological history of the universe, and more. This volume begins with an excellent pedagogical introduction to the physics and methods and formalism of supersymmetry which is accessible to anyone with a basic knowledge of the Standard Model of particle physics.Next is an overview of open questions, followed by chapters on topics such as how to detect superpartners and tools for studying them, the current limits on superpartner masses as we enter the LHC era, the lightest superpartner as a dark matter candidate in thermal and non-thermal cosmological histories, and associated Z'' physics. Most chapters have been extended and updated from the earlier edition and some are new. This superb book will allow interested physicists to understand the coming experimental and theoretical progress in supersymmetry and the implications of discoveries of superpartners, and will also help students and workers to quickly learn new aspects of supersymmetry they want to pursue.
The Higgs Hunter's Guide
Author: John F. GunionPublisher: CRC Press
ISBN: 0429976070
Category : Science
Languages : en
Pages : 333
Book Description
The Higgs Hunter's Guide is a definitive and comprehensive guide to the physics of Higgs bosons. In particular, it discusses the extended Higgs sectors required by those recent theoretical approaches that go beyond the Standard Model, including supersymmetry and superstring-inspired models.