370 research outputs found
A Multivariate Approach to Dilepton Analyses in the Upgraded ALICE Detector at CERN-LHC
No full textALICE, the dedicated heavy-ion experiment at CERN-LHC, will undergo a major upgrade in 2019/20. This work aims to assess the feasibility of conventional and multivariate analysis techniques for low-mass dielectron measurements in Pb-Pb collisions in a scenario involving the upgraded ALICE detector with a low magnetic field (). These electron-positron pairs are promising probes for the hot and dense medium, which is created in collisions of ultra-relativistic heavy nuclei, as they traverse the medium without significant final-state modifications. Due to their small signal-to-background ratio, high-purity dielectron samples are required. They can be provided by conventional analysis methods, which are based on sequential cuts, however at the price of low signal efficiency. This work shows that existing methods can be improved by employing multivariate approaches to reject different background sources of the dielectron invariant mass spectrum. The major background components are dielectrons from photon conversion and combinatorial pairs. By implementing deep neural networks, the signal-to-background ratio can be improved by up to 60% over existing results in the case of pure conversion rejection and up to 30% in the case of additional suppression of all combinatorial background components. In both cases, the gain in significance is about 15% compared to conventional approaches. Additionally, different strategies for rejecting heavy flavor pairs (i.e., dielectrons originating from or ) are studied and some of their major challenges identified. In general, it is concluded that multivariate techniques are a powerful and promising approach to dielectron analyses since they significantly improve the results over conventional methods in terms of signal-to-background ratio and significance. Moreover, these techniques remove complexity from existing implementations as they allow to (1) base the analyses on individual tracks (instead of track pairs), essentially without sacrificing analysis performance, (2) render some of the existing and involved analysis methods obsolete and, to some degree, (3) obviate the need for manual input feature engineering
Search for displaced dimuons in proton-proton collisions at = 13 TeV with the CMS muon system
No full textLong-lived particles (LLPs) naturally appear in many well-motivated theories beyond the Standard Model of Particle Physics (SM). These LLPs could be produced in high-energy particle collisions and subsequently decay into known particles, which can be detected a measurable distance away from the LLP point of creation. This work presents an inclusive search for neutral, exotic LLPs in events with pairs of oppositely charged muons originating from a common displaced vertex. The underlying dataset was recorded by the CMS detector during the LHC Run 2 and comprised an integrated luminosity of 97.6 fb of proton-proton collisions at a center-of-mass energy of = 13 TeV. The search is sensitive to LLP decays beyond the CMS tracking system because it uses muons reconstructed by the CMS muon detectors only. To measure the relevant muon trigger and reconstruction efficiencies as a function of displacement and to assess systematic uncertainties and scale factors in the analysis, performance studies were carried out with cosmic-ray muons recorded by CMS in 2016. The results are interpreted in the context of two benchmark models: (1) a scenario in which the final-state muons are the decay products of a generic long-lived, scalar boson from anon-SM Higgs initial state (“BSM heavy scalar“ model), and (2) the “Hidden Abelian Higgs model“ which features long-lived, scalar “dark photons“ as the intermediate LLP states giving rise to displaced dimuons in the final state. Upper limits on the production cross-sections in both interpretations are presented for a wide range of LLP mass-lifetime hypotheses. In all scenarios, there is good agreement between expected and observed upper limits and no statistically significant excess over the predicted SM background is reported
Simulation of the Position Resolution of a Scintillation Detector
No full textIn the Standard Model of particle physics, CPT symmetry is regarded as invariant. In order to test this prediction, the ASACUSA collaboration (“Atomic Spectroscopy And Collisions Using Slow Antiprotons”) aims to make a very precise measurement of the hyperfine structure of antihydrogen with a Rabi-like experiment. The compar- ison of the experimentally-obtained antihydrogen transition frequencies with those of hydrogen allows for a direct test of CPT symmetry. The spectrometer line of the ASACUSA HBAR-GSHFS (“Antihydrogen ground state hyperfine splitting”) experiment consists of a particle source, a spin flip-in- ducing microwave cavity, a spin-analyzing sextupole magnet, and a detector. In the course of the work for this thesis, a single scintillation detector as used in the hodoscopes of the detector at the end of the spectrometer line was simulated using the particle physics toolkit Geant4. Subsequent analysis of the simulation data allows for an estimate of the minimal uncertainty in determining the location of a particle’s point of impact on the detector geometry
Search for displaced dimuons in proton-proton collisions at √s = 13 TeV with the CMS muon system
No full textLong-lived particles (LLPs) naturally appear in many well-motivated theories beyond the Standard Model of Particle Physics (SM). These LLPs could be produced in high-energy particle collisions and subsequently decay into known particles, which can be detected a measurable distance away from the LLP point of creation. This work presents an inclusive search for neutral, exotic LLPs in events with pairs of oppositely-charged muons originating from a common displaced vertex. The underlying dataset was recorded by the CMS detector during the LHC Run 2 and comprised an integrated luminosity of 97.6 fb-1 of proton-proton collisions at a center-of-mass energy of √s = 13 TeV. The search is sensitive to LLP decays beyond the CMS tracking system because it uses muons reconstructed by the CMS muon detectors only. To measure the relevant muon trigger and reconstruction eciencies as a function of displacement and to assess systematic uncertainties and scale factors in the analysis, performance studies were carried out with cosmic-ray muons recorded by CMS in 2016. The results are interpreted in the context of two benchmark models: (1) a scenario in which the final-state muons are the decay products of a generic long-lived, scalar boson from a non-SM Higgs initial state (“BSM heavy scalar” model), and (2) the “Hidden Abelian Higgs model” which features long-lived, scalar dark photons as the intermediate LLP states giving rise to displaced dimuons in the final state. Upper limits on the production cross-sections in both interpretations are presented for a wide range of LLP mass–lifetime hypotheses. In all scenarios, there is good agreement between expected and observed upper limits and no statistically significant excess over the predicted SM background is reported
Ein multivarianter Zugang zur Dileptonanalyse mit dem verbesserten ALICE Detektor am CERN-LHC
No full textdeu: ALICE, eines der vier großen Experimente am CERN–LHC, wird in denJahren 2019/20 einem umfassenden Upgrade unterzogen werden. Die vorliegende Arbeit dient der Abschätzung der Realisierbarkeit von konventionellenund multivariaten Analysetechniken für die Messung von Di-Elektronen mitgeringer Masse in Pb-Pb-Kollisionen in einem Szenario, das den verbessertenALICE-Detektor mit einem geringen Magnetfeld (B = 0.2 T) involviert. InKollisionen von ultrarelativistischen, schweren Kernen wird ein heißes unddichtes Medium erzeugt. Elektron-Positron-Paare stellen vielversprechende Sonden für dieses Medium dar, da sie es ohne signifikante Änderungen ihresfinalen Zustandes durchqueren. Aufgrund ihres geringen Signal-Untergrund-Verhältnisses werden Proben mit hoher Reinheit benötigt. Diese können durch konventionelle Analysemethoden, welche auf sequentiellen Schnitten basieren, auf Kosten von geringer Signaleffizienz bereitgestellt werden. Die vorliegende Arbeit zeigt, dass existierende Ansätze durch den Einsatz multivariater Methoden zur Unterdrückung verschiedener Untergrund-Quellen im Di-Elektronen-Massenspektrum verbessert werden können. Die Hauptkomponen-te des Untergrund sind Di-Elektronen von Photon-Konversionen und kombinatorische Di-Elektronenpaare. Der Einsatz von “tiefen” neuronalen Netzwerken(deep neural networks) ermöglicht eine Verbesserung des Signal-Untergrund-Verhältnisses von bis zu 60 % im Vergleich zu existierenden Ergebnissen im Falle von multivariater Unterdrückung des Konversionsuntergrundes und biszu 30 % im Falle von zusätzlicher Unterdrückung aller kombinatorischer Komponenten. In beiden Fällen erhöht sich die Signifikanz um etwa 15 % im Vergleich zu herkömmlichen Ansätzen. Außerdem werden verschiedene Strategien zur Unterdrückung von heavy flavor-Paaren (i. e., von c¯c oder b¯b herrührende Di-Elektronen) untersucht und die damit verbundenen Herausforderungen identifiziert. Da multivariate Methoden im Vergleich zu konventionellen Methoden die Ergebnisse hinsichtlich des Signal-Untergrund-Verhältnisses und der Signifikanz bedeutend verbessern, wird allgemein die Schlussfolgerung ge-zogen, dass diese Methoden einen leistungsfähigen und vielversprechenden Ansatz für die Analyse von Di-Elektronen darstellen. Weiters verringern multivariate Methoden die Komplexität existierender Implementierungen, in dem sie ermöglichen, (1) die Analysen auf Basis einzelner Teilchenspuren (i. e.,tracks) durchzuführen, anstelle von Paaren von tracks, (2) manche eingesetzten und aufwendigen Analysemethoden zu ersetzen, ohne die Analyseergebnisse dabei nennenswert zu verschlechtern, und (3) das manuelle Konstruieren von Inputvariablen bis zu einem gewissen Grad hinfällig zu machen.ALICE, the dedicated heavy-ion experiment at CERN–LHC, will undergo a major upgrade in 2019/20. This work aims to assess the feasibility of conventional and multivariate analysis techniques for low-mass dielectron measurements in Pb-Pb collisions in a scenario involving the upgraded ALICE detector with a low magnetic field (B=0.2 T). These electron-positron pairs are promising probes for the hot and dense medium, which is created in collisions of ultra-relativistic heavy nuclei, as they traverse the medium without significant final-state modifications. Due to their small signal-to-background ratio, high-purity dielectron samples are required. They can be provided by conventional analysis methods, which are based on sequential cuts, however at the price of low signal efficiency. This work shows that existing methods can be improved by employing multivariate approaches to reject different background sources of the dielectron invariant mass spectrum. The major background components are dielectrons from photon conversion and combinatorial pairs. By implementing deep neural networks, the signal-to-background ratio can be improved by up to 60% over existing results in the case of pure conversion rejection and up to 30% in the case of additional suppression of all combinatorial background components. In both cases, the gain in significance is about 15% compared to conventional approaches. Additionally, different strategies for rejecting heavy flavor pairs (i.e., dielectrons originating from ccbar or bbbar) are studied and some of their major challenges identified. In general, it is concluded that multivariate techniques are a powerful and promising approach to dielectron analyses since they significantly improve the results over conventional methods in terms of signal-to-background ratio and significance. Moreover, these techniques remove complexity from existing implementations as they allow to (1) base the analyses on individual tracks (instead of track pairs), essentially without sacrificing analysis performance, (2) render some of the existing and involved analysis methods obsolete and, to some degree, (3) obviate the need for manual input feature engineering
Aesop: The Complete Fables
No full textHere is an apparent second printing in 2008 of the Chinese translation from 2002 of Penguin's new edition of Aesop done in 1998 by Olivia and Robert Temple. The work includes Robert Temple's extensive introduction to this translation. This book adds an element that the original had lacked: a T of C at the beginning. There is a short afterword in Chinese on 385-7. The English appears on left-hand pages. The Chinese translation and a rare note or two appear on the right-hand pages. This Chinese collection shows excellent political correctness. It contains 357 fables, not 358, and they are ordered according to the Temples' order. A bit of sleuthing easily unearths the excluded fable: The Chariot of Hermes and the Arabs (#112 on 87 in the Temples' edition). This fable involves a racial slur. For more about the book by the Temples, consult my comment on their 1998 edition or my review of it for Classical Outlook. There are no illustrations here other than the FG illustration that appears both on the front cover and on the title-page.Language note: Bilingual: English/ChineseSecond printing?Translated by Olivia and Robert Templ
The phenomenon of existential indifference : if it does not even bother you that your life is meaningless
No full textDiese wissenschaftliche Arbeit beschäftigt sich mit dem Phänomen der existenziellen Indifferenz. Die Jugendzeit ist eine Phase geprägt von großen Entwicklungsschritten, einem Reifungsprozess, wegweisenden Entscheidungen und vielen Unsicherheiten. Welche Auswirkungen die veränderten Gesellschaftsstrukturen, die unzähligen beruflichen und freizeittechnischen Möglichkeiten haben, war der Verfasserin dieser Masterarbeit zunächst unklar. Relevant ist diese Thematik dahingehend, da das Phänomen der existenziellen Indifferenz eine Phase ist, die häufig als eine Nebenerscheinung während des Entwicklungsprozesses von jungen Menschen auftreten kann. Die existenzielle Indifferenz beschreibt eine Sinnleere, die es Jugendlichen erschwert, sich zu entscheiden, Motivation für diverse Erledigungen aufzubringen, an sich und ihrem Charakter zu arbeiten und konkrete Ziele zu verfolgen. Ziel dieser Arbeit ist es daher herauszufinden, welche gesellschaftlichen Rahmenbedingungen zu dem Phänomen führen können. Ebenso spielen Medien und Erziehung in diesem Kontext eine erhebliche Rolle und können Gründe für die Entstehung der existenziellen Indifferenz sein. Letztlich sollen Lösungsansätze aufgezählt werden. Die Inhalte dieser Masterarbeit obliegen einer präzisen Recherche, wissenschaftlichen Literaturquellen und den Gesprächen mit acht ExpertInnen. Diese Interviews wurden anschließend mithilfe der Inhaltsanalyse nach Gläser und Laudel ausgewertet.Die Ergebnisse zeigen auf, dass die existenzielle Indifferenz meist als eine Begleiterscheinung im Entwicklungsprozess junger Menschen vorkommt. Der Boden, von dem sich das Phänomen nähren kann, besteht aus einer grenzenlosen Erziehung, zu viel Freiheiten in jungen Jahren, schlechten Vorbildern und dem unbegleiteten Nutzen der digitalen Medien. Ebenso wird ersichtlich, dass sich das Phänomen dann zeigt, wenn Menschen keine sinnvollen Aufgaben verfolgen und primär mit sich selbst beschäftigt sind. Die Ergebnisse zeigen deutlich, dass sich das Phänomen in erster Linie in Wohlstandgesellschaften zeigt, also bei Jugendlichen, denen alle Stolpersteine aus dem Weg geräumt werden und die keine Selbstwirksamkeit leben, da ihnen schon im Vorhinein alles geboten wird. Im Umgang mit existenziell indifferenten Personen ist es wichtig, ressourcenorientiert zu arbeiten und sie dahingehend zu leiten, sinnvolle Aufgaben zu entdecken, die auf jemanden oder etwas anderes bezogen sind.This scientific work with the title “The existential indifference. If it does not even bother you that your life is meaningless” deals with senselessness in early ages of children and teenagers. Youth is a time characterized by great developmental stages, a maturing process, groundbreaking decisions and many uncertainties. The effects of the changed social structures, which have countless professional and recreational opportunities, were initially unclear to the author of this master's thesis. Relevant is this issue because the phenomenon of existential indifference is a life stage that can often appear as a by-product during the developmental process of young people. The existential indifference describes a meaninglessness that makes it difficult for young people to decide, to raise motivation for various tasks, to work on themselves and their character and to pursue tangible goals.The aim of this work is therefore to find out which social framework conditions can lead to the phenomenon. Similarly, media and education play a significant role in this context and can be reasons for the emergence of the phenomenon of existential indifference. Finally, solutions are going to be mentioned based on this topic. The contents of this thesis are subject to a precise research, scientific sources of literature and the discussions with eight experts. These interviews were then evaluated using the content analysis by Gläser and Laudel.The results show that the phenomenon of existential indifference usually occurs as a concomitant in the developmental process of young people. The soil from which the phenomenon can nourish consists of boundless education, too much freedom at a young age, bad role models and the unaccompanied use of digital media. It also becomes apparent that the phenomenon manifests itself when people do not pursue meaningful tasks and are primarily concerned with themselves. The results clearly show that the phenomenon is primarily in affluent societies, precisely young people, where all stumbling blocks were removed and who do not live the self-efficacy, since they are already offered everything in advance. In dealing with existentially indifferent individuals, it is important to work resource-oriented and guide them to discover meaningful tasks that are related to someone or something else.vorgelegt von Naomi TemplZusammenfassungen in Deutsch und EnglischAbweichender Titel laut Übersetzung des Verfassers/der VerfasserinMasterarbeit Karl-Franzens-Universität Graz 2019 2.63
Jesus' Purification of the Jerusalem Temple: Historicity and Theological Accents in Gospels
No full textThe thesis "Jesus Cleansing the Jerusalem Temple: History and Theological Accents in Individual Gospels" deals with the event described by all four canonical Gospels. The paper describes the appearance of the Jerusalem Temple in Jesus' time and selected aspects of its spiritual, political, economic and sociological role in the life of the Jewish population of Palestine in the 1st century AD. The author notices the selected negative circumstances that could have led Jesus of Nazareth to enter the Jerusalem temple with the intention of disrupting the order and returning the Temple to its original purpose. The author pays great attention to evidence to confirm the theory that the "event" in the Temple occurred twice. One at the beginning of Jesus' public activity (described in the Gospel according to John) and once at the end (described in synoptics). Further, the author pays attention to the arguments in support of the historicity of the described events. Keywords Jesus of Nazareth, Jerusalem Temple, Gospel, Historicity, Cleansing of the Templ
The R Journal (June 2015) 7(1): Complete Issue
No full textEditorial, Bettina Grün
Contributed Research Articles
Peptides: A Package for Data Mining of Antimicrobial Peptides, Daniel Osorio, Paola Rondón-Villarreal, and Rodrigo Torres
fanplot: An R Package for Visualising Sequential Distributions, Guy J. Abel
sparkTable: Generating Graphical Tables for Websites and Documents with R, Alexander Kowarik, Bernhard Meindl, and Matthias Templ
rdrobust: An R Package for Robust Nonparametric Inference in Regression-Discontinuity Designs, Sebastian Calonico, Matias D. Cattaneo, and Rocío Titiunik
Frames2: A Package for Estimation in Dual Frame Surveys, Antonio Arcos, David Molina, Maria Giovanna Ranalli, and María del Mar Rueda
The Complex Multivariate Gaussian Distribution, Robin K. S. Hankin
sae: An R Package for Small Area Estimation, Isabel Molina and Yolanda Marhuenda
showtext: Using System Fonts in R Graphics, Yixuan Qiu
Correspondence Analysis on Generalised Aggregated Lexical Tables (CA-GALT) in the FactoMineR Package, Belchin Kostov, Mónica Bécue-Bertaut, and François Husson
Implementing Persistent O(1) Stacks and Queues in R, Shawn T. O’Neil
R as an Environment for Reproducible Analysis of DNA Amplification Experiments, Stefan Rödiger, Michał Burdukiewicz, Konstantin Blagodatskikh, Michael Jahn, and Peter Schierack
The gridGraphics Package, Paul Murrell
fslr: Connecting the FSL Software with R, John Muschelli, Elizabeth Sweeney, Martin Lindquist, and Ciprian Crainiceanu
Identifying Complex Causal Dependencies in Configurational Data with Coincidence Analysis, Michael Baumgartner and Alrik Thiem
Manipulation of Discrete Random Variables with discreteRV, Eric Hare, Andreas Buja, and Heike Hofmann
Estimability Tools for Package Developers, Russell V. Lenth
News and Notes
R Foundation News, Kurt Hornik
Changes on CRAN, Kurt Hornik and Achim Zeileis
Changes in R, R Core Team
News from the Bioconductor Project, Bioconductor Tea
Aesop's Fables
No full textHere are twelve fables on eight pages -- and the back-cover. Another piece on the back-cover announces A selection of timelessly poignant vignettes from the celebrated author of The Boy Who Cried 'Wolf,' The Tortoise and the Hare, and The Camel Who Shat in the River. (Regretably not included in this volume). True to the style of comics, the visuals carry the stories here. On one page, three fables are done in three strips across the page. The first of these is one of the author's best, The Sick Man and the Doctor. The facial expressions of the sick man in all four cells reveal his feelings. Marsden's presentation of The Amorous Lion and the Ploughman may make us wonder for the first time what the girl thought about all this! Marsden's portrait of Aesop on the inside back-cover is fine. I enjoy this author's humor. Here is how he finishes the short blurb on Aesop: His pithy anecdotes are as funny, satirical and educatonal today as they were 2,500 years ago. Sort of. Sort of! I also enjoy the author's copyright claim on the back of the front cover: All remaining material, for what it's worth, is ©2005 Phillip Marsden… There's probably some kind of fable in there somewhere!Robert and Olivia Templ
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