1,721,097 research outputs found
Flavour predictions in the Standard Model and beyond
No full textThis thesis reports on two projects concerning flavour physics. In the first project it is shown how approximate Minimal Flavour Violation (MFV) can emerge from an SU(5) Supersymmetric Grand Unified Theory (SUSY GUT) supplemented by an S4 x U(1) family symmetry, which provides a good description of all quark and lepton (including neutrino) masses, mixings and CP violation. Assuming a SUSY breaking mechanism which respects the family symmetry, the low energy mass insertion parameters are calculated in full explicit detail in the super-CKM basis, including the effects of canonical normalisation and renormalisation group running. It is found that the very simple family symmetry S4 x U(1) is sufficient to approximately reproduce the effects of low energy MFV where required but there is also a suggestion of testable new physics. Numerical estimates of the low energy mass insertion parameters are presented for well-defined ranges of SUSY parameters and the naive model expectations are compared to the numerical scans and the experimental bounds. The results are then used to estimate the predictions for Electric Dipole Moments (EDMs), Lepton Flavour Violation (LFV), B and K meson mixing as well as rare B decays. The largest observable deviations from MFV come from the LFV process μ → eγ and the EDMs.In the second project, matrix elements of the chromomagnetic operator, often denoted by O8, between B/D-states and light mesons plus an off-shell photon are calculated, by employing the method of light-cone sum rules (LCSR) at leading twist 2. These matrix elements are relevant for flavour changing transition processes, such as B → K*l+l- and they can be seen as the analogues of the well-known penguin form factors T1;2;3 and fT . A large CP-even phase is found, for which a long-distance (LD) interpretation is given. Results are compared to QCD factorisation (QCDF), for which the spectator photon emission is end-point divergent. The analytic structure of the correlation function used in the LCSR method, admits a complex anomalous threshold on the physical sheet, the meaning and handling of which is discussed
Phenomenological implications of an SU(5) × S4 × U(1) SUSY GUT of flavor
No full textWe discuss the characteristic low energy phenomenological implications of an SU (5) supersymmetric (SUSY) grand unified theory whose flavor structure is controlled by the family symmetry S4×U(1), which provides a good description of all quark and lepton masses, mixings as well as charge parity violation. Although the model closely mimics minimal flavor violation (MFV) as shown in M. Dimou, S.?F. King, and C. Luhn, J. High Energy Phys. 02 (2016) 118., here we focus on the differences. We first present numerical estimates of the low energy mass insertion parameters, including canonical normalization and renormalization group running, for well-defined ranges of SUSY parameters and compare the naive model expectations to the numerical scans and the experimental bounds. Our results are then used to estimate the model-specific predictions for electric dipole moments (EDMs), lepton flavor violation (LFV), B and K meson mixing as well as rare B decays. The largest observable deviations from MFV come from the LFV process µ → e γ and the electron EDM
Exclusive chromomagnetism in heavy-to-light FCNCs
No full textWe compute matrix elements of the chromomagnetic operator, often denoted by O 8 , between B/D states and light mesons plus an off-shell photon by employing the method of light-cone sum rules at leading twist-2. These matrix elements are relevant for processes such as B?K ? l + l ? and they can be seen as the analogues of the well-known penguin form factors T 1,2,3 and f T . We find a large CP -even phase for which we give a long-distance interpretation. We compare our results to QCD factorization for which the spectator photon emission is end-point divergent. The analytic structure of the correlation function used in our method admits a complex anomalous threshold on the physical sheet. The meaning and handling within the sum rule approach of the anomalous threshold is discussed
Approaching minimal flavour violation from an SU(5) × S4 × U(1) SUSY GUT
Full text linkWe show how approximate Minimal Flavour Violation (MFV) can emerge from an SU(5) Supersymmetric Grand Unified Theory (SUSY GUT) supplemented by an S 4 × U(1) family symmetry, which provides a good description of all quark and lepton (including neutrino) masses, mixings and CP violation. Assuming a SUSY breaking mechanism which respects the family symmetry, we calculate in full explicit detail the low energy mass insertion parameters in the super-CKM basis, including the effects of canonical normalisation and renormalisation group running. We find that the very simple family symmetry S 4 ×U(1) is sufficient to approximately reproduce the effects of low energy MFV
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
WIT Talk with Noor Afshan Fathima, CERN IT accessibility studies' ally
No full textNoor Afshan Fathima is a Fullstack Engineer with CERN IT’s Search-As-A-Service project. She has been a volunteer at the Open Source community since 2011 with a focus on introducing students to open source philosophy and helping them migrate to open source. She has volunteered at a local specially-abled children’s school in India on certain occasions. She is a recipient of the Google Women TechMakers Scholarship and IEEE Computer Society's Richard E. Merwin Scholarship.
Noor participated in the 2021 edition of CERN’s Global Webfest, where she pitched the idea for “Crowdsourced designs, 3D printed enhancements for the disabled” (https://webfest.cern/node/339) which stems from the open-source philosophy of open collaboration model where the able-bodied world can contribute to building custom enhancements suited for each disabled person’s needs. This idea was prototyped during the weekend and won first place. In addition, she is a volunteer at Hackahealth Foundation (https://www.hackahealth.ch/) which fosters a community that operates on similar ideologies at Campus Biotech in Geneva (https://www.campusbiotech.ch/en/) and is collaborating on Team Caroline (https://www.hackahealth.ch/project-caroline-2021).
Noor envisions forming more of these communities which will provide free and safe spaces for people like herself with disabilities to express their needs and build solutions in an inclusive and systematic approach, in collaboration with able-bodied people, thereby bridging the gap through consistent innovation for a healthier co-existence of all diverse individuals.
Noor will be interviewed by Maria Dimou. Maria graduated in Physics from Athens university and Computing from the university of Brussels. After almost 5 years of permanent contract with IBM, she resigned to join a research environment. She is CERN IT dept. staff for 34 years. Her projects include the email gateway evolution, network configuration in the computer centre for the SHIFT project, Web operation and deputy Group Leader's role in the Web Office, Linux support, various Grid middleware packages in WLCG, the IT e-learning initiative, an investigation of Markdown for static documentation, a web-based Slides' maker and Solid - the Decentralised Web project by the Web inventor Sir Tim Berners-Lee. She loves human languages, is an amateur dancer and believes that art should be a mandatory aspect of education and an important part of everybody's life.
Noor and Maria both work in CERN IT.
Links:
https://webfest.cern/node/339
https://www.hackahealth.ch/hackathons-en</div
Variations on the Author
Full text link“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
Full text linkWe 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
Full text linkWe 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
- …
