1,720,962 research outputs found
Optimization of Spin Coherence Time at a Prototype Storage Ring for Electric Dipole Moment Investigations
No full textIl modello standard della fisica delle particelle finora non è stato in grado di spiegare la asimmetria materia-antimateria osservata nell'Universo. I Momenti di Dipolo Elettrico (EDM) delle particelle fondamentali sono sonde molto sensibili della fisica oltre il modello standard. La collaborazione JEDI sta conducendo una di queste ricerche, con l'obiettivo di misurare direttamente i Momenti di Dipolo Elettrico di particelle cariche utilizzando un fascio polarizzato in anelli di accumulazione. L'obiettivo potrà essere raggiunto eseguendo la misura in un anello di accumulazione puramente elettrostatico, che può "congelare" la precessione di spin dei protoni sul piano orizzontale. Come fase intermedia, si propone un "prototipo" di anello di accumulazione più piccolo, in grado di utilizzare una combinazione di campi elettrici e magnetici, che serva a dimostrare il principio di base e per comprendere meglio le sistematiche richieste. Un parametro fondamentale da ottimizzare per raggiungere la massima sensibilità possibile nella misura EDM è il Tempo di Coerenza dello Spin (SCT) del fascio polarizzato accumulato nell'anello, cioè l'intervallo di tempo entro il quale le particelle del fascio mantengono una polarizzazione netta maggiore di 1/e del valore iniziale. Per identificare le condizioni di lavoro che massimizzano l'SCT, sono state eseguite accurate simulazioni delle dinamiche dello spin nel reticolo del prototipo dell'anello. Questo studio presenta un'indagine sulla variazione dei parametri del fascio e dello spin che influenzano l'SCT, nonché una strategia di ottimizzazione per le impostazioni dei sestupoli per ottenere il Tempo di Coerenza dello Spin più elevato in qualsiasi condizione di lavoro dell'anello. Lo studio fornisce un set di dati di molte configurazioni con differenti Tempi di Coerenza dello Spin sufficientemente elevati da soddisfare i requisiti di sensibilità della misurazione EDM. Analizza inoltre i possibili fattori di progettazione che possono avere un impatto negativo sugli SCT e discute possibili riconfigurazioni o aggiornamenti per migliorare questi valori in futuro.The standard model of particle physics has thus far fallen short of being able to explain the observed amount of matter-antimatter asymmetry in the Universe. Electric Dipole Moments (EDMs) of fundamental particles are very sensitive probes of physics beyond the Standard Model. The JEDI collaboration is dedicated to the measurement of the electric dipole moments of charged particles by using a polarized beam in storage rings. The goal can be accomplished by performing the measurement in a pure electrostatic storage ring, which can freeze the horizontal spin precession of protons. As an intermediate step, a smaller "prototype" storage ring, capable of using a combination of electric and magnetic fields, is proposed to serve as a proof-of-principle and to better understand the required systematics. A fundamental parameter to be optimised to reach the highest possible sensitivity in the EDM measurement is the Spin Coherence Time (SCT) of the stored polarized beam, that is the time interval within which the particles of the stored beam maintain a net polarisation greater than 1/e of its initial value. To identify the working conditions that maximise SCT, accurate spin dynamics simulations have been performed on the lattice of the prototype ring. This study presents an investigation of the variation of the beam and spin parameters that influence SCT as well as an optimisation strategy for the sextupole settings to obtain the highest spin coherence time at any given working condition of the ring. The study provides a data set of many configurations with spin coherence times high enough to meet the sensitivity requirements of the EDM measurement. It also analyses the possible design factors that may negatively impact SCTs and discusses possible reconfigurations or design upgrades to improve these values in the future
Search for Electric Dipole Moments and Axions/ALPS with Polarized Beams in Storage RIngs
No full textThe research investigates two main questions in particle physics and cosmology: the fate of antimatter after the Big Bang and the nature of Dark Matter (DM). It focuses on studying Electric Dipole Moments (EDMs) in particles like protons and deuterons using polarized particle beams in a storage ring. Research and developments have been till now experimentally pursued at the COoler SYnchrotron (COSY) storage ring at Forschungszentrum-Jülich in Germany which has been shut-down at the end of 2023. The next stage involves designing a Prototype Storage Ring (PSR), both all-electric and hybrid (electric and magnetic), with a beam energy of 30-45 MeV and a circumference of around 100 m. The PSR aims to prepare for a final EDM facility, addressing technical uncertainties for measuring a proton EDM. Following the PSR phase, a precision EDM facility with 233 MeV energy and 500 m circumference will seek to significantly enhance the neutron's static EDM limit, potentially leading to significant discoveries
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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