Search results for "FIELD"
showing 10 items of 15048 documents
Highly occupied gauge theories in 2 + 1 dimensions : a self-similar attractor
2019
Motivated by the boost-invariant Glasma state in the initial stages in heavy-ion collisions, we perform classical-statistical simulations of SU(2) gauge theory in 2+1 dimensional space-time both with and without a scalar field in the adjoint representation. We show that irrespective of the details of the initial condition, the far-from-equilibrium evolution of these highly occupied systems approaches a unique universal attractor at high momenta that is the same for the gauge and scalar sectors. We extract the scaling exponents and the form of the distribution function close to this non-thermal fixed point. We find that the dynamics are governed by an energy cascade to higher momenta with sc…
Effective Field Theories for heavy probes in a hot QCD plasma and in the early universe
2017
There are many interesting problems in heavy-ion collisions and in cosmology that involve the interaction of a heavy particle with a medium. An example is the dissociation of heavy quarkonium seen in heavy-ion collisions. This was believed to be due to the screening of chromoelectric fields that prevents the heavy quarks from binding, however in the last years several perturbative and lattice computations have pointed out to the possibility that dissociation is due to the finite lifetime of a quarkonium state inside the medium. Regarding cosmology, the study of the behavior of heavy Majorana neutrinos in a hot medium is important to understand if this model can explain the origin of dark ma…
The Co-Design of a Counter-Narrative Social Campaign: Second Generation Youths Against Radicalization
2021
This paper deals with the OLTRE project (ISF - DG Migration and Home Affairs, EU) funded for preventing the radicalization of the second-generation of migrants in Italy. This essay aims to study the production of an online communication campaign co-designed by second-generation youths. The four Universities engaged in the project, in order to collect the issues for the campaign made an in-depth sociological research and an interdisciplinary social network analysis. We will present the results of the non-standard field research. Starting from the different dimensions of the risk of radicalization proposed by the kaleidoscopic overview of risk factors (Sieckelinck and Gielen 2018: 5; Ranstorp…
Encuentro de saberes: Huellas de memoria pluriversa y descolonización de la Universidad contemporánea
2018
This paper studies the Encounter of Knowledge as a project that, by welcoming mestres and mestras of ancestral knowledge into universities, contributes to decolonize higher education, broadening its field of memory. Based on a systematization exercise, we established a theoretical dialogue with Bajtin and Bejamin. Based on the participation of four mestres -Lucely Pío, raicera del Cerrado, Mãe Lu and Tata Mutá Imé, religious leaders of Candomblé and the political leader and shaman Álvaro Tukano of the Tukano nation- we show how the project promotes in the contemporary Brazilian university a space of mnemic pluriversity, capable of activating diverse narrative planes (biographical, political…
First observation and study of the K± → π±π0e+e− decay
2018
The NA48/2 experiment at CERN reports the first observation of the K-+/- -> pi(+/-)pi(0)e(+)e(-) decay from an exposure of 1.7 x 10(11) charged kaon decays recorded in 2003-2004. A sample of 4919 candidates with 4.9% background contamination allows the determination of the branching ratio in the full kinematic region, BR(K-+/- -> pi(+/-)pi(0)e(+)e(-)) = (4.24 +/- 0.14) x 10(-6). The study of the kinematic space shows evidence for a structure dependent contribution in agreement with predictions based on chiral perturbation theory. Several P- and CP-violating asymmetries are also evaluated.
Crystal field and magnetism with Wannier functions: Rare-earth doped aluminum garnets
2015
Using the recently developed method we calculate the crystal field parameters in yttrium and lutetium aluminum garnets doped with seven trivalent Kramers rare-earth ions. We then insert calculated parameters into the atomic-like Hamiltonian taking into account the electron-electron, spin-orbit and Zeeman interactions and determine the multiplet splitting by the crystal field as well as magnetic $\hat{g}$ tensors. We compare calculated results with available experimental data.
Hard Two-Photon Contribution to Elastic Lepton-Proton Scattering Determined by the OLYMPUS Experiment
2017
The OLYMPUS collaboration reports on a precision measurement of the positron-proton to electron-proton elastic cross section ratio, $R_{2\gamma}$, a direct measure of the contribution of hard two-photon exchange to the elastic cross section. In the OLYMPUS measurement, 2.01~GeV electron and positron beams were directed through a hydrogen gas target internal to the DORIS storage ring at DESY. A toroidal magnetic spectrometer instrumented with drift chambers and time-of-flight scintillators detected elastically scattered leptons in coincidence with recoiling protons over a scattering angle range of $\approx 20\degree$ to $80\degree$. The relative luminosity between the two beam species was mo…
Teoría de la educación : educación y cultura en la sociedad de la información
2011
Se exponen las principales perspectivas en el estudio del comportamiento informacional: la perspectiva del usuario y la del sistema. En el primer caso, se asume una visión global del proceso de búsqueda de información y se desarrollan modelos teóricos y metodológicos para guiar la investigación en este campo. Se presentan como ejemplo la teoría del Sense-Making de Brenda Dervin y el modelo de Proceso de Búsqueda de Información de Carol Kuhlthau. En el segundo caso, se asume una perspectiva parcial del proceso de búsqueda de información, centrándose fundamentalmente en las transacciones entre usuario y el sistema o entre el usuario y la información. Se describen los estudios del uso de recur…
The territorial dimension in the EU programming and the New Framework for Public Policies: Territorial Tural Development, CAP Reform and new LEADER
2012
Lo que venimos denominando como perspectiva territorial del desarrollo es un fenómeno bastante reciente en el contexto de la Unión Europea, de apenas dos décadas. En esencia esta perspectiva territorial del desarrollo se ha centrado en un enfoque local de los procesos de desarrollo en las áreas rurales, de la mano, principalmente, de instrumentos como LEADER. La necesidad de incorporar la dimensión territorial a los procesos de desarrollo proviene no solo del éxito global de estos instrumentos, sino también por el convencimiento de que puede constituir un elemento fundamental de cara a la cohesión económica y social en el seno de la UE. Avances recientes, como el Libro Verde de la Cohesión …
Four-dimensional representation of scattering amplitudes and physical observables through the application of the Loop-Tree Duality theorem
2019
Las últimas dos décadas han sido testigo de un tremendo progreso en la física teórica de alta precisión. Muchos avances han sido hechos, en particular, en la evaluación de diagramas multi-loop, pero el principal desafío yace en el tratamiento de las divergencias IR a través de eficientes esquemas de substracción. Con la complejidad del procedimiento incrementándose exponencialmente con el número de escalas, se ha hecho necesario tratar la cuestión desde un ángulo diferente, invocando así al desarrollo de nuevas técnicas. La Dualidad Lazo-Árbol (LTD, por sus siglas en inglés) provee de un nuevo marco para el cómputo de amplitudes con loops. A través de la modificación de la prescripción está…