New flavor physics in bb decays

A new $U(1)$ gauge boson coupling predominantly to the third family has been considered in connection with recent LEP data. We consider another likely consequence of such a gauge boson, a greatly enhanced $b$ quark decay mode, b \to s \nnbar.Comment: 6 pages, Latex documen

Penguin decays of B mesons

Penguin, or loop, decays of B mesons induce effective flavor-changing neutral currents, which are forbidden at tree level in the Standard Model. These decays give special insight into the CKM matrix and are sensitive to non-standard model effects. In this review, we give a historical and theoretical introduction to penguins and a description of the various types of penguin processes: electromagnetic, electroweak, and gluonic. We review the experimental searches for penguin decays, including the measurements of the electromagnetic penguins b -> s gamma and B -> K* gamma and gluonic penguins B -> K pi, B+ -> omega K+ and B -> eta' K, and their implications for the Standard Model and New Physics. We conclude by exploring the future prospects for penguin physics.Comment: 49 pages, LATEX, 30 embedded figures, submitted to Annual Reviews of Nuclear and Particle Scienc

Metakognitives Wissen in der Sekundarstufe: Konstruktion und Evaluation domänenspezifischer Messverfahren. Projekt EWIKO

Deklaratives metakognitives Wissen stellt neben prozeduralen metakognitiven Fertigkeiten eine notwendige Voraussetzung zur Steuerung kognitiver Prozesse dar. Aufgrund psychometrischer Probleme stehen jedoch kaum Messverfahren zur Erfassung dieser Komponente metakognitiver Kompetenz zur Verfügung. In der vorliegenden Studie wurden domänenspezifische Verfahren zur Erfassung des deklarativen metakognitiven Wissens in den Domänen Lesen, Mathematik, Englisch und im selbstregulierten Lernen für den Einsatz zu Beginn der Sekundarstufe adaptiert bzw. neu konstruiert. Die vier Wissenstests basieren auf domänenspezifischen Szenarien und rekurrieren auf die Einschätzung der relativen Nützlichkeit von Strategien. Die Testkonstruktion wurde an einer Stichprobe von 798 bayerischen Schüler/innen der 5. und 6. Jahrgangsstufe aus den Schularten Hauptschule und Gymnasium validiert. Die interne Konsistenz (Cronbachs Alpha) der vier Verfahren ist zufrieden stellend bis gut. In allen vier Domänen zeigen sich deutliche Wissensunterschiede sowohl zwischen den untersuchten Jahrgangsstufen als auch zwischen den untersuchten Schularten. Die konstruierten Verfahren bilden das Leistungsspektrum am Beginn der Sekundarstufe reliabel und valide ab. Weitere, längsschnittliche Analysen zu den Entwicklungsmustern des deklarativen metakognitiven Wissens innerhalb und zwischen den Domänen sind notwendig. (DIPF/Autor

Data-in-Place: Thinking through the Relations Between Data and Community

We present findings from a year-long engagement with a street and its community . The work is targeted at exploring how the production and use of data is bound up with place, both in terms of physical and social geography. We detail three strands of the project. First, we consider how residents have sought to curate existing data about the street in the form of an archive with physical and digital components. Second, we report endeavours to capture data about the street’s environment, especially of traffic moving through it. Third, we draw on the possibilities afforded by technologies for polling opinion. We reflect on how these engagements have: materialised distinctive relations between the community and their data; surfaced flows and contours of data , and spatial, temporal and social boundaries ;and enacted a multiplicity of ‘small worlds’. We consider how such a conceptualisation of data-in-place is relevant to the design of data technologies

Rare radiative B decay to the orbitally excited K_2^*(1430) meson

The exclusive rare radiative B meson decay to the orbitally excited tensor K_2^*(1430) meson is investigated in the framework of the relativistic quark model based on the quasipotential approach in quantum field theory. The calculated branching ratio BR(B --> K_2^*(1430)\gamma)=(1.7\pm 0.6)\times 10^{-5} as well as the ratio BR(B --> K_2^*(1430)\gamma)/BR(B --> K^*(892)\gamma)=0.38\pm 0.08 is found in a good agreement with recent experimental data from CLEO.Comment: 10 pages, RevTe

Information Tactics of Immigrants in Urban Environments

Introduction. This project seeks to contribute to research on everyday human information behaviour by addressing the information practices of immigrants (here called migrational individuals) engaged in learning about new urban environments.Method. Two qualitative approaches are used: semi-structured, in-depth interviews and participatory mapping (a methodology involving analysis of maps produced by interviewees). The twelve participants interviewed in this project were migrational individuals recruited from an English language learning and acculturation centre in New York, NY.Analysis. Using Certeau\u27s construct of tactics as a theoretical frame, interviews were transcribed and coded with NVIVO software. Analysis focused on practices used by migrational individuals in order to become familiar with New York, sources of surprise and instances of being lost in the city, and technologies and resources that were (or were not) useful in learning about daily life as a recent arrival to an urban environment.Results. Main findings from analysis of interviews include: a detailed account of multiple information resources used in everyday life information seeking, the extent to which personal narrative and biography (such as work history) shapes interpretations of surroundings, and the deliberate use of wandering to become familiar with new environments. These findings are theorized in terms of everyday life information seeking. The term information tactics is suggested as particularly salient for understanding daily practices of navigating unfamiliar city space.Conclusions. Through discussion of migrational individuals\u27 information practices, possible developments for public libraries and acculturation programmes seeking to provide improved services for the immigrant community are suggested. With both practical and theoretical implications, this project provides in-depth perspectives on an understudied group within library and information science research

The Case for Many Internets

Internet studies research often concentrates on mainstream platforms, practices, and users at the expense of people and technologies at the margin. This article introduces a collection of essays that addresses the gap in research, taking a number of different approaches. Indeed, arguing for a diverse and multi-faceted understanding of digital technologies can take a number of forms, including studying platforms that are incredibly common yet rarely investigated, looking at practices that fall outside the scope of mainstream communication research, and investigating communities that are non-Western, non-urban, and/or non-heteronormative. Research in these areas is crucial in developing a broader understanding of online platforms, and for expanding theoretical frameworks related to technology, media, and communication

Networked Field Studies: Comparative Inquiry and Online Communities

In this article, I articulate a methodology for comparative qualitative analysis of online communities, which I refer to as networked field studies. I describe networked field studies as an approach that allows for looking across multiple communities and field sites to build a coherent set of analytical claims about the role of technology and everyday life, drawing on my own research investigating relationships to digital technologies among three countercultural communities. The major aim of this article is to contribute to methodological discussions on comparative qualitative analysis within Internet studies, foregrounding how research on digital technologies can both benefit from and complicate a comparative approach. After a brief summary of the communities studied in the research that has given rise to this methodological approach, I outline key methodological concepts and address the strengths and limitations of networked field studies as a method for analyzing socio-technical practices in everyday life

Adjusting The Borders: Bisexual Passing And Queer Theory

Fluidity is a term sometimes used in reference to bisexual identity, thus positioning sexuality as an adaptive, evolving set of behaviors performed to constitute alternately straightness or queerness. Part of the speciousness of using fluidity to describe bisexuality centers on the implication that heterosexuality and homosexuality occupy opposite ends of a psychological spectrum, leaving bisexuality vaguely straddling poles of identity, without specificity or intent. This article is predominantly concerned with the notion of intentionality in bisexual behavior and whether or not deliberate choices are made to participate in communities that identify as either straight or queer. Rather than framing this investigation in terms of whether or not sexuality itself is a choice, this article compares bisexuals who alternately engage in straight or queer practices in the context of passing, as when a person presents herself as an alternate race. Using personal narratives, theoretical works from Judith Butler, bell hooks and Eve Kosofsky Sedgwick, and drawing on descriptions of racial passing, I am interested in crafting psychological profiles of women who routinely perform their sexualities differently as part of belonging to and identifying with distinct communities of queerness and straightness