The Physics of the B Factories

This work is on the Physics of the B Factories. Part A of this book contains a brief description of the SLAC and KEK B Factories as well as their detectors, BaBar and Belle, and data taking related issues. Part B discusses tools and methods used by the experiments in order to obtain results. The results themselves can be found in Part C

Measurement of the e^(+)e^(-)→ bb(macron) cross section between √s = 10.54 and 11.20 GeV

We report e^(+)e^(-)→ bb(macron) cross section measurements by the BABAR experiment performed during an energy scan in the range of 10.54 to 11.20 GeV at the SLAC PEP-II e^(+)e^(-) collider. A total relative error of about 5% is reached in more than 300 center-of-mass energy steps, separated by about 5 MeV. These measurements can be used to derive precise information on the parameters of the Y (10860) and Y (11020) resonances. In particular we show that their widths may be smaller than previously measured

Lawson criterion for ignition exceeded in an inertial fusion experiment

For more than half a century, researchers around the world have been engaged in attempts to achieve fusion ignition as a proof of principle of various fusion concepts. Following the Lawson criterion, an ignited plasma is one where the fusion heating power is high enough to overcome all the physical processes that cool the fusion plasma, creating a positive thermodynamic feedback loop with rapidly increasing temperature. In inertially confined fusion, ignition is a state where the fusion plasma can begin "burn propagation" into surrounding cold fuel, enabling the possibility of high energy gain. While "scientific breakeven" (i.e., unity target gain) has not yet been achieved (here target gain is 0.72, 1.37 MJ of fusion for 1.92 MJ of laser energy), this Letter reports the first controlled fusion experiment, using laser indirect drive, on the National Ignition Facility to produce capsule gain (here 5.8) and reach ignition by nine different formulations of the Lawson criterion

Ich spreche anders, aber das ist auch deutsch: línguas em conflito em uma escola rural localizada em zona de imigração no sul do Brasil Ich spreche anders, aber das ist auch deutsch: languages in conflict in a rural school located in an immigration area in the south of Brazil

O bilingüismo/multilingüismo como fenômeno social ainda é pouco reconhecido no cenário brasileiro, apesar de o tema ter conquistado espaço na academia. Em termos gerais, considera-se o Brasil um país monolíngüe, onde se fala apenas o português brasileiro. Há, no entanto, vários contextos de línguas minoritárias (grupos indígenas, grupos de imigrantes, zonas de fronteira, comunidades de surdos) em que o uso de várias línguas é a regra. Nesses contextos sociolingüisticamente complexos há relações assimétricas e de conflito entre a língua hegemônica e as línguas minoritárias, em geral estigmatizadas. O presente estudo, parte dos resultados de uma pesquisa etnográfica, focaliza o conflito lingüístico presente em uma escola rural localizada numa comunidade bilíngüe/multilíngüe em zona de imigração alemã no sul do país, onde, ainda hoje, as crianças aprendem em casa a língua de herança, empregada em âmbito familiar e social. Com suporte teórico predominantemente vindo do bilingüismo visto de uma perspectiva social e dos Estudos Culturais, o objetivo principal deste artigo é problematizar a situação de contato/conflito lingüístico existente na região alvo da pesquisa e sua interface com questões de identidades construídas nos discursos hegemônicos. Além disso, discute-se como esses conflitos emergem nas relações interacionais entre os professores e entre alunos e professores, dentro da instituição escolar. Os registros sugerem que o bilingüismo da comunidade penetra na escola e que os conflitos lingüísticos e identitários ganham ainda mais força nas interações sociais entre os sujeitos que ali convivem.<br>Bilingualism/multilingualism as a social phenomenon is still little recognized in the Brazilian scenario, despite it has gotten space in the academy. Usually, Brazil is seen as a monolingual country, where the Brazilian Portuguese is the only language spoken. There are, however, contexts of minority languages (indigenous groups, groups of immigrant, border regions, deaf communities) in which the use of several languages is the rule. In these sociolinguistically complex contexts there are both asymmetric and conflicting relations between the hegemonic language and minority languages, usually stigmatized. This study develops itself from the results of an ethnographic research, focusing the language conflict that is present in a rural school located in a bilingual/multilingual community in a region of German immigration in the south of the country, where, even nowadays, children learn at home the inherited language, which is used in the familiar and social contexts. With a theoretical basis mostly acquired from bilingualism analyzed from a social perspective and from the perspective of the Cultural Studies, the main aim of this article is to problematize the language contact/conflict situation existing in the target region and its interface with identity questions built in the hegemonic discourses. Moreover, it is discussed the way these conflicts emerge in the interactional relations between teachers and among teachers and students within school. The data suggests that the community's bilingualism gets into school, and that the language and identity conflicts become even stronger within the social interactions among the individuals that live together in that space