Search for a narrow t(t)over-bar resonance in p(p)over-bar collisions at root s=1.96 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

SEMICLASSICAL ESTIMATE OF THE COULOMB-EXCITATION OF THE GIANT-DIPOLE RESONANCE IN PB-208

A semiclassical approach to study pure Coulomb excitation of Pb-208 giant dipole isovector resonance is examined. We consider medium energy projectiles and assume the target excitation to be described by a simple Goldhaber-Teller model. It is shown that the main features concerning the angular distribution are obtained in the angular range described by the model and an estimate is made of the pure Coulomb dipole contribution to the measured cross sections.

Resonance in positron-helium scattering at medium energy

A narrow S-wave resonance has been found in the positron-helium system at about 30 eV, using the close-coupling approach, in excitation and rearrangement cross sections to He(1s2s), He(1s2p), Ps(1s) and Ps(2s) states by employing different combinations of the following basis functions: He(1s1s), He(1s2s), He(1s2p), Ps(1s) and Ps(2s), where Ps stands for the positronium atom.

Influence of the resonance in a gravity-gradient stabilized satellite

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

State Dependent Riccati Equation (SDRE) control method applied in cancellation of a parametric resonance in a magnetically levitated body

Here, a simplified dynamical model of a magnetically levitated body is considered. The origin of an inertial Cartesian reference frame is set at the pivot point of the pendulum on the levitated body in its static equilibrium state (ie, the gap between the magnet on the base and the magnet on the body, in this state). The governing equations of motion has been derived and the characteristic feature of the strategy is the exploitation of the nonlinear effect of the inertial force associated, with the motion of a pendulum-type vibration absorber driven, by an appropriate control torque [4]. In the present paper, we analyzed the nonlinear dynamics of problem, discussed the energy transfer between the main system and the pendulum in time, and developed State Dependent Riccati Equation (SDRE) control design to reducing the unstable oscillatory movement of the magnetically levitated body to a stable fixed point. The simulations results showed the effectiveness of the (SDRE) control design. Copyright © 2011 by ASME.

Contribution of magnetic resonance in acute spinal cord trauma - case report

Acute spinal cord trauma is a common injury that occurs frequently in small animals. In order to acertain a prognosis of the lesion generated in the spinal cord, it is necessary to perform a complete neurological and physical examination, aided by complementary images. Magnetic resonance imaging may be advantageous over other types of images, because it can determine with greater definition the structural damage to the nervous tissue. The objective of this report was to demonstrate the contribution of magnetic resonance imaging in a case of acute spinal cord trauma in a dog.

A radiologic morphometric study of sellar, infrassellar and parasellar regions by magnetic resonance in adults

To evaluate variations of some anatomic structures of sellar and parasellar regions and their possible differences between genders and age groups. Magnetic resonance images (MRI) of 380 patients were performed to analyze the dimensions of the sphenoid sinus, pituitary gland, optic chiasm, intra-cavernous carotid distances, distance between columella nasal - sphenoid sinus; and columella nasal-pituitary gland. The patients age ranged between 20 and 80 years (mean age 48 years). The study included 235 females (mean age 53 years) and 145 males (mean age 40 years). The transverse length of the pituitary, the inter-carotid distance and the height of the pituitary were similar between genders and age groups. The width and height of the optic chiasm showed differences only between females of different ages. Males presented greater distances between nasal columella and sphenoid sinus. The most common type of pneumatization of the sphenoid sinus was the sellar, and depending on the age group, sphenoid sinus was larger in males than females. The anatomy of the Sellar and parasellar regions is complex and varies widely within the normal range. They are a small area, rich in anatomical details affecting multiple physiological systems in the body and, therefore, have great importance in several medical fields. A better understanding of these complex structures is essential in clinical diagnosis and treatment of disease.

Probing the decay characteristics of the Pygmy Dipole Resonance in the semi-magic nucleus 140 Ce with gamma-gamma coincidence measurements

Im Rahmen dieser Arbeit wurde ein neuartiger Experimentaufbau -- das γ3 Experiment -- zur Messung von photoneninduzierten Kern-Dipolanregungen in stabilen Isotopen konzipiert und an der High Intensity γ-Ray Source (HIγS) an der Duke University installiert.rnDie hohe Energieauflösung und die hohe Nachweiseffizienz des Detektoraufbaus, welcher aus einer Kombination von LaBr Szintillatoren und hochreinen Germanium-Detektoren besteht, erlaubt erstmals die effiziente Messung von γ-γ-Koinzidenzen in Verbindung mit der Methode der Kernresonanzfluoreszenz.rnDiese Methode eröffnet den Zugang zum Zerfallsverhalten der angeregten Dipolzustände als zusätzlicher Observablen, die ein detaillierteres Verständnis der zugrunde liegenden Struktur dieser Anregungen ermöglicht.rnDer Detektoraufbau wurde bereits erfolgreich im Rahmen von zwei Experimentkampagnen in 2012 und 2013 für die Untersuchung von 13 verschiedenen Isotopen verwendet. Im Fokus dieser Arbeit stand die Analyse der Pygmy-Dipolresonanz (PDR) im Kern 140Ce im Energiebereich von 5,2 MeV bis 8,3 MeV basierend auf den mit dem γ3 Experimentaufbau gemessenen Daten. Insbesondere das Zerfallsverhalten der Zustände, die an der PDR beteiligt sind, wurde untersucht. Der Experimentaufbau, die Details der Analyse sowie die Resultate werden in der vorliegenden Arbeit präsentiert. Desweiteren erlaubt ein Vergleich der Ergebnisse mit theoretischen Rechnungen im quasi-particle phonon model (QPM) eine Interpretation des beobachteten Zerfallsverhaltens.

Measurements of Four-Lepton Production at the Z Resonance in pp Collisions at √s=7 and 8 TeV with ATLAS

Measurements of four-lepton (4ℓ , ℓ=e,μ ) production cross sections at the Z resonance in pp collisions at the LHC with the ATLAS detector are presented. For dilepton and four-lepton invariant mass regions m ℓ + ℓ − >5  GeV and 80ing the nonresonant 4ℓ production contributions and normalizing with Z→μ + μ − events, the branching fraction for the Z boson decay to 4ℓ is determined to be (3.20±0.25(stat)±0.13(syst))×10 −6 , consistent with the standard model prediction.

Tunable Fano resonance in symmetric multilayered gold nanoshells

Fano resonances (FRs) are produced when a discrete state is coupled with a continuum. In addition to fundamental scientific interests, FRs in plasmonic systems give rise to the so-called plasmon-induced transparency. In this work we have studied the evolution of dipole-dipole all-plasmonic FRs in symmetric multilayered nanoshells as the function of their geometrical parameters. We demonstrate that symmetry breaking is not mandatory for controlling the Fano resonance in such multilayered nanoshells. Generation of FRs in these symmetric nanostructures presents clear advantages over their asymmetric counterparts, as they are easier to fabricate and can be used in a wider range of technological applications.

Tunable Fano resonance in symmetric multilayered gold nanoshells

We have studied the evolution of dipole–dipole all-plasmonic Fano resonances (FRs) in symmetric multilayered nanoshells as a function of their geometrical parameters. We demonstrate that symmetry breaking is not mandatory for controlling the Fano resonance in such multilayer structures. By carefully selecting the geometrical parameters, the position of the FR can be tuned between 600 and 950 nm and its intensity can be increased up to four fold with respect to the non-optimized structures. Generation of FRs in such symmetric nanostructures presents clear advantages over their asymmetric counterparts, as they are easier to fabricate and can be used in a wider range of technological applications.