1,041 research outputs found
Sterile neutrino decay and the LSND experiment
We propose a new explanation of the intriguing LSND evidence for electron
antineutrino appearance in terms of heavy (mostly sterile) neutrino decay via a
coupling with a light scalar and light (mostly active) neutrinos. We perform a
fit to the LSND data, as well as all relevant null-result experiments, taking
into account the distortion of the spectrum due to decay. By requiring a
coupling g ~ 10^{-5}, a heavy neutrino mass m_4 ~ 100 keV and a mixing with
muon neutrinos |U_{mu 4}|^2 ~ 10^{-2}, we show that this model explains all
existing data evading constraints that disfavor standard (3+1) neutrino models.Comment: 3pp. Talk given at 9th International Conference on Astroparticle and
Underground Physics (TAUP 2005), Zaragoza, Spain, 10-14 Sep 200
Literacia, ensino da leitura e sucesso escolar
Nas últimas décadas, tem se observado uma crescente demanda pelo domínio da
linguagem escrita em todas as áreas da vida social (Olson 2009). Essa demanda não se
limita apenas ao contexto brasileiro, mas refere-se a um contexto mundial, que hoje
coloca o domínio das diversas capacidades de linguagem, em especial das capacidades
de leitura e escrita, como condição para acesso ao conhecimento, à participação social e
o exercício efetivo da cidadania. O domínio de tais capacidades refere-se a um certo
tipo ou nível de literacia que vai além da descodificação, diz respeito às diversas
capacidades de leitura e escrita necessárias em diferentes práticas sociais. Partindo
de uma parceria de investigação entre instituições de ensino superior em Portugal e no
Brasil, temos vindo a reflectir sobre questões de currículo nos dois países.ABSTRACT
In the last decades, a growing demand for the domain of written language in all areas of
social life has been observed (Olson 2009). This demand is not limited to the Brazilian
context, but concerns a global context which now sets the domain of different language
skills, especially skills in reading and writing as a condition for access to knowledge,
social participation and effective exercise of citizenship. The domain of these skills
concerns a certain type or level of literacy that goes beyond decoding, refers to the
different reading and writing skills required in different social practices. From a
research partnership between universities and research centers in Portugal and Brazil,
we have been reflecting on issues of curriculum in both countries
Event Stream Processing with Multiple Threads
Current runtime verification tools seldom make use of multi-threading to
speed up the evaluation of a property on a large event trace. In this paper, we
present an extension to the BeepBeep 3 event stream engine that allows the use
of multiple threads during the evaluation of a query. Various parallelization
strategies are presented and described on simple examples. The implementation
of these strategies is then evaluated empirically on a sample of problems.
Compared to the previous, single-threaded version of the BeepBeep engine, the
allocation of just a few threads to specific portions of a query provides
dramatic improvement in terms of running time
- …