214 research outputs found
Soft Pomerons and the Forward LHC Data
Recent data from LHC13 by the TOTEM Collaboration on and
have indicated disagreement with all the Pomeron model predictions by
the COMPETE Collaboration (2002). On the other hand, as recently demonstrated
by Martynov and Nicolescu (MN), the new datum and the unexpected
decrease in the value are well described by the maximal Odderon
dominance at the highest energies. Here, we discuss the applicability of
Pomeron dominance through fits to the \textit{most complete set} of forward
data from and scattering. We consider an analytic
parametrization for consisting of non-degenerated Regge
trajectories for even and odd amplitudes (as in the MN analysis) and two
Pomeron components associated with double and triple poles in the complex
angular momentum plane. The parameter is analytically determined by
means of dispersion relations. We carry out fits to and data on
and in the interval 5 GeV - 13 TeV (as in the MN
analysis). Two novel aspects of our analysis are: (1) the dataset comprises all
the accelerator data below 7 TeV and we consider \textit{three independent
ensembles} by adding: either only the TOTEM data (as in the MN analysis), or
only the ATLAS data, or both sets; (2) in the data reductions to each ensemble,
uncertainty regions are evaluated through error propagation from the fit
parameters, with 90 \% CL. We argument that, within the uncertainties, this
analytic model corresponding to soft Pomeron dominance, does not seem to be
excluded by the \textit{complete} set of experimental data presently available.Comment: 10 pages, 4 figures, 1 table. Two paragraphs and four references
added. Accepted for publication in Phys. Lett.
Modeling of a gimbal azimuth drive and simulation of control techniques
A common problem in developing new gimbal products is predicting performance. At the beginning of the design stage, typically the proposal writing stage, it is critical to be able to anticipate the performance of a design, which may still be very roughly defined. Static performance metrics such as pointing accuracy are easier to predict and can be related to position sensor resolution and compliance in the structure and drive. Dynamic performance metrics such as rate tracking and bandwidth are much more difficult to estimate. These dynamic parameters will serve as the results of this paper. A gimbal model is usually developed in this early stage of design. A model is built for each axis as cross-coupling is not usually significant. The development of each model is inherently dependent on the integrity of the parameters used. Some parameters may be easily accessible and clearly defined, such as manufacturer specifications for commercial-off-the-shelf (COTS) components. An example of these would be motors. A motor datasheet will usually include specifications such as winding resistance, torque constant, etc. Some parameters have to estimated such as drive friction, structural rigidity and drive parameters. There is also much less certainty in these estimates due to their dependence on the integrated, final system. Building an accurate and sufficient model of the system is a challenging task. This thesis developments and validates a single axis gimbal model. Following this is a recursion on the model parameters based upon empirical data. Finally, application of different control laws are evaluated in simulation on the model. First, a classical output feedback law is implemented. Secondly, a state observer is implemented with state feedback. State feedback coefficients are found using both pole placement (PP) algorithms and linear quadratic regulation (LQR) optimal control formulas
Proton-proton forward scattering at the LHC
Recently the TOTEM experiment at the LHC has released measurements at
TeV of the proton-proton total cross section, ,
and the ratio of the real to imaginary parts of the forward elastic amplitude,
. Since then an intense debate on the -parity asymptotic nature of the
scattering amplitude was initiated. We examine the proton-proton and the
antiproton-proton forward data above 10 GeV in the context of an eikonal
QCD-based model, where nonperturbative effects are readily included via a QCD
effective charge. We show that, despite an overall satisfactory description of
the forward data is obtained by a model in which the scattering amplitude is
dominated by only crossing-even elastic terms, there is evidence that the
introduction of a crossing-odd term may improve the agreement with the
measurements of at TeV. In the Regge language the
dominant even(odd)-under-crossing object is the so called Pomeron (Odderon).Comment: 5 pages, 2 figures, 1 table. Phenomenological approach revised,
results and conclusions changed, suggesting now the presence of Odderon
effects in forward scattering (once confirmed the TOTEM data at 13 TeV
El cambio de 'vosotros' por 'ustedes' en la adaptación latinoamericana de la Biblia
El presente trabajo se integra en un proyecto de investigación que se propone indagar en perspectiva histórica las políticas lingüísticas referidas a la Los hablantes reconocen, intuitivamente, las diferencias entre su variedad lingüística y las que hablan otros grupos. Las distintas variedades pueden ser generadas por factores geográficos, sociales o situacionales, pero los usuarios siempre las reconocen al compararlas con su variante vernácula que consideran 'no marcada'. El presente trabajo surge de la observación de que el uso de la forma 'vosotros' como pronombre de 2º persona plural, propia del español peninsular, genera, en el hablante de español americano, una connotación desde el plano del significante. Esto se debe a los efectos de sentido que provoca en el oyente hispanoamericano la oposición usted / vosotros. En el caso de los textos bíblicos, la versión preparada para Hispanoamérica utiliza 'usted' en todos los casos en que se refiere a la 2º persona plural, con las adecuaciones morfosintácticas correspondientes. El hablante latinoamericano de español percibe esta adaptación como 'no marcada'. El objetivo de este trabajo es detectar la connotación producida en el plano del significante por las variantes vinculadas con el uso de la 2º persona plural en el texto bíblico, y mostrar, asimismo, los matices que surgen de esas variantes combinatorias. Para realizar este análisis se comparan tres versiones del mismo fragmento del Nuevo Testamento, separadas en cinco segmentos cada una. Se revisa la bibliografía sobre el tema, partiendo de las definiciones de la Real Academia Española de la Lengua, considerando la perspectiva sociolingüística y tomando los aportes de L. Hjelmslev y C. Kerbrat-Orecchioni a la problemática de la connotación. Se concluye que el esfuerzo por acercar el texto bíblico a la variedad vernácula del español americano implica también la pérdida de los efectos connotativos que genera el uso de 'vosotros' en América.Facultad de Humanidades y Ciencias de la Educació
O princípio da livre convicção motivada do juiz na análise da prova pericial no âmbito penal
O estudo demonstra a análise do princípio da livre convicção motivada do juiz, constante no art. 93, inciso IX, da Constituição Federativa do Brasil de 1988, bem como a análise da produção de prova pericial no âmbito penal e a (in) possibilidade de aplicação do referido princípio a fim de afastar as conclusões do laudo pericial. Tal assertiva resta clara a partir de uma análise jurídico-constitucional de princípios consagrados na Constituição Federal, onde se defende a liberdade de julgamento das decisões proferidas pelo magistrado, muito embora as mesmas necessitem obrigatoriamente de pronunciamento motivado, com as respectivas justificativas do porque de determinada conclusão. Para tanto, utilizou-se como método de abordagem o dedutivo e, como técnica de procedimento, a monográfica, efetuandose as consultas e pesquisas necessárias na doutrina, jurisprudência e principalmente na legislação de regência. A monografia encontra-se dividida em três capítulos, versando, nesta ordem, sobre o processo penal brasileiro, numa abordagem conceitual e evolutiva, alguns dos princípios norteadores do processo penal brasileiro, bem assim, o estudo dos meios de prova no processo penal, da produção de prova pericial em especial e, por fim, o foco do trabalho, a análise do principio da livre convicção motivada do juiz na análise da prova pericial no âmbito penal. Conclui o trabalho que o enfoque do tema sob o viés seguido torna possível a aplicação da livre convicção, a luz da produção da prova pericial, todavia de forma motivada e justificada, de modo a garantir a cristalização das decisões jurisdicionais, e a clareza para a compreensão dos cidadãos em geral
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