Nonmesonic weak decay of Λ-hypernuclei within independent-particle shell-model

After a short introduction to the nonmesonic weak decay (NMWD) ΛN→nN of Λ-hypernuclei we discuss the long-standing puzzle on the ratio Γn/Γp, and some recent experimental evidences that signalized towards its final solution. Two versions of the Independent-Particle-Shell-Model (IPSM) are employed to account for the nuclear structure of the final residual nuclei. They are: (a) IPSM-a, where no correlation, except for the Pauli principle, is taken into account, and (b) IPSM-b, where the highly excited hole states are considered to be quasi-stationary and are described by Breit-Wigner distributions, whose widths are estimated from the experimental data. We evaluate the coincidence spectra in Λ 4He, Λ 5He, Λ 12C, Λ 16O, and Λ 28Si, as a function of the sum of kinetic energies EnN=En+EN for N=n, p. The recent Brookhaven National Laboratory experiment E788 on Λ 4He, is interpreted within the IPSM. We found that the shapes of all the spectra are basically tailored by the kinematics of the corresponding phase space, depending very weakly on the dynamics, which is gauged here by the one-meson-exchange- potential. In spite of the straightforwardness of the approach a good agreement with data is achieved. This might be an indication that the final-state- interactions and the two-nucleon induced processes are not very important in the decay of this hypernucleus. We have also found that the π+K exchange potential with soft vertex-form-factor cutoffs (Λπ≈0. 7GeV, ΛK≈0.9GeV), is able to account simultaneously for the available experimental data related to Γp and Γn for Λ 4H, and Λ 5He. © 2010 American Institute of Physics.

Statics and dynamics of a binary dipolar Bose-Einstein condensate soliton

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

O experimento e o lúdico: reflexões sobre atividades didáticas experimentais para o ensino de Física e a ludicidade

In this work, is discussed the importance of experimental activities in Education of Physics in Basic Education from the experience of Supervised Stage and the work with the Initiation of Teaching in the Program PIBID CAPES, in this case linked to the Department of Education of the Institute of Biosciences, Campus Rio Claro, São Paulo State, in partnership with three schools of basic education in the city. At first, based on the work of Ferreira with Instrumentation for Teaching Physics, consider the electrostatic theme. The focus is the searching for equipments constructed with low cost materials and easy access. Were developed and promoted strategies of the use of such materials in Physics’ Teaching, with a view to reintroducing experimental teaching activities in Public Basic Education, in the form Workshop Learning and Teaching of Physics, as well as lessons of Laboratory with the help of script and also in the form of an Experiments Library. These experimental activities were critically analyzed with a focus on playfulness. The focus of work in experimental activities for the Physics’ Teaching allowed to redeem, critically, didactic materials. From the standpoint of playfulness, playful moments and interaction of individuals with the knowledge that provides the experimental material when used strategically, they seem to be of great relevance to the Physics’ Teaching in Basic Education. It is possible to use experiments in Physics’ Teaching in public schools

Future Brazilian teachers imaginaries about physics teaching in adults education

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Pedagogical practices carried out during an in-service teachers education project: approaching history and philosophy of science to physics teaching

We report here part of a research project developed by the Science Education Research Group, titled: "Teachers’ Pedagogical Practices and formative processes in Science and Mathematics Education" which main goal is the development of coordinated research that can generate a set of subsidies for a reflection on the processes of teacher training in Sciences and Mathematics Education. One of the objectives was to develop continuing education activities with Physics teachers, using the History and Philosophy of Science as conductors of the discussions and focus of teaching experiences carried out by them in the classroom. From data collected through a survey among local Science, Physics, Chemistry, Biology and Mathematics teachers in Bauru, a São Paulo State city, we developed a continuing education proposal titled “The History and Philosophy of Science in the Physics teachers’ pedagogical practice”, lasting 40 hours of lessons. We followed the performance of five teachers who participated in activities during the 2008 first semester and were teaching Physics at High School level. They designed proposals for short courses, taking into consideration aspects of History and Philosophy of Science and students’ alternative conceptions. Short courses were applied in real classrooms situations and accompanied by reflection meetings. This is a qualitative research, and treatment of data collected was based on content analysis, according to Bardin [1].

Estratégias experimentais de ensino visando contribuir com o ensino de Física de modo significativo: atividades de eletricidade, magnetismo e eletromagnetismo

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)