827 research outputs found
Upper secondary students face optical diffraction using simple experiments and on-line measurements
No full textA research-based educational path on diffraction of light was designed for upper secondary
schools. Through the experimental exploration of the diffraction pattern produced by a laser
beam incident on a single slit, students first analyse the diffraction pattern qualitatively,
recognizing the global properties, then measuring with on-line sensors the light intensity vs
position, constructing empirical relations between order and position of minimum, order and
position of maximum, position and intensity of maximum. Making a wave hypothesis on the
nature of light, a computer model based on Huygens' principle takes into account the intensity
pattern of light. Experiments in school were performed with students, using inquiry based
learning tutorial worksheets e pre-test, post-test. Positive learning indications of students
emerged concerning the role of diffraction in everyday situations, and the general features of the
diffraction pattern. The findings suggests that to produce an effective change in the model of
light, students need to reflect extensively in the hypothesis at the base of their prevision and to
by involved in deep in a modelling activity
Searches for Squarks and Gluinos at the Tevatron
No full textWe present results on a search for squarks and gluinos performed on data from proton-antiproton collisions collected using the CDF and D0 detectors at the Fermilab Tevatron. Events with multiple jets of hadrons and large missing transverse energy in the final state are studied within the framework of minimal supergravity (mSUGRA) and assuming R-parity conservation. At D0, the search for squarks has also been performed in the topology of multijet events accompanied by large missing transverse energy and at least one tau lepton decaying hadronically. Preliminary results are presente
- …
