Measurement of the W-Pair Production Cross Section and W-Decay Branching Fractions in e+e−e^{+}e^{-} Interactions at s\sqrt{s}= 189 GeV

The data collected by the L3 experiment at LEP at a centre-of-mass energy of $188.6~\rm{Ge\kern -0.1em V}$ are used to measure the W-pair production cross section and the W-boson decay branching fractions. These data correspond to an integrated luminosity of 176.8~pb$^{-1}$. The total cross section for W-pair production, combining all final states, is measured to be $\sigma_{\rm{WW}}= 16.24 \pm 0.37~(stat.) \pm 0.22~(syst.)$~pb. Including our data collected at lower centre-of-mass energies, the hadronic branching fraction of the W-boson is determined to be $B(\rm{W} \rightarrow \rm{qq})= \left[ 68.20 \pm 0.68~(stat.) \pm 0.33~(syst.)\right]~\%$. The results agree with the Standard Model predictions.The data collected by the L3 experiment at LEP at a centre-of-mass energy of 188.6 GeV are used to measure the W-pair production cross section and the W-boson decay branching fractions. These data correspond to an integrated luminosity of 176.8pb^-1. The total cross section for W-pair production, combining all final states, is measured to be sigma_WW = 16.24 +/- 0.37(stat.) +/- 0.22(syst.) pb. Including our data collected at lower centre-of-mass energies, the hadronic branching fraction of the W-boson is determined to be B(W ->qq) = [68.20 +/- 0.68 (stat.) +/- 0.33 (syst.) ] %. The results agree with the Standard Model predictions.The data collected by the L3 experiment at LEP at a centre-of-mass energy of 188.6 GeV are used to measure the W-pair production cross section and the W-boson decay branching fractions. These data correspond to an integrated luminosity of 176.8 pb −1 . The total cross section for W-pair production, combining all final states, is measured to be σ WW =16.24±0.37 (stat.)±0.22 (syst.) pb. Including our data collected at lower centre-of-mass energies, the hadronic branching fraction of the W-boson is determined to be B (W→qq)=[68.20±0.68 (stat.)±0.33 (syst.)]%. The results agree with the Standard Model predictions

Improving secondary students’ scientific literacy and laboratory skills: the Italian Project “Scientific Degrees”

An overview of the Italian National Project “Progetto Lauree Scientifiche” (PLS, Scientific Degrees Project is presented (http://www.progettolaureescientifiche.eu/). The Project, established in 2005 by the Ministry of Education, University and Research, was initially aimed at addressing the constant decrease, since 2000, in the enrolment of secondary school students in tertiary scientific education. The involved University degrees have been: Chemistry, Mathematics, Physics, Sciences of Materials. Due to the strong focus on motivating students towards scientific-related professional careers, the Project was developed in cooperation also with the Italian National Board of Industries, to give students an informed view about employment possibilities in industrial companies. From the scientific viewpoint, the main objectives have been to: enhance knowledge of Science contents and perception about Nature of Science through laboratory activities that actively involve students; improve competences of in-service teachers on laboratory activities focusing on both contents and methodological aspects; help students become aware of their own scientific knowledge and of the pre-requisites requested to take full advantage of the University curricula; deepen special Science topics for the most motivated students. In this paper, a brief overview of the PLS Project is presented. Then, emblematic activities carried at the Naples Department of Physics are described. Finally, some conclusions are drawn

Integrating scientific inquiry and technological design activities using microcomputer-based laboratories.

Research findings suggest the inclusion of design activities in science teaching to foster students’ learning of scientific/technological contents. Integration with inquiry-based activities has also been suggested to improve engagement in authentic practices. We propose a Teaching-Learning Sequence (TLS), “The insulated house”, which integrates scientific inquiry and technological design activities using a blend of traditional and microcomputer-based laboratories. The TLS was developed within an Italian National Project aimed at improving students’ scientific literacy. The activities have involved 15 students (17-18 years-old) of a Technical School. The contents addressed are: heat, temperature, materials thermal properties. First, an experiment to describe/interpret cooling/heating of a water quantity was done with thermometers and temperature probes; data analysis allowed to identify the mathematical function describing the temperature vs. time trend and the physical parameters of the phenomenon (e.g. conductivity, exchange surface, thickness, etc…). Then, the students were asked to design the walls of an house to met certain temperature requirements in the inner rooms. A prototype “house” with 3 “rooms” separated by “walls” of different materials was built and tested to verify that the materials met the desired requirements when illuminated by an artificial “sun” (high wattage lamp). In each room a sensor measured the temperature. The students drew on the experiment results to investigate the influence of the walls’ material on the heating curve of each room and identify the most suitable materials for walls’ construction. Analysis of answers to an open question shows that the proposed integrated activities improved students’ views about Science and Technology relationships

Integrating scientific inquiry and technological design activities using microcomputer-based laboratories

Research findings suggest the inclusion of design activities in science teaching to foster students’ learning of scientific/technological contents. Integration with inquiry-based activities has also been suggested to improve engagement in authentic practices. We propose a Teaching-Learning Sequence (TLS), “The insulated house”, which integrates scientific inquiry and technological design activities using a blend of traditional and microcomputer-based laboratories. The TLS was developed within an Italian National Project aimed at improving students’ scientific literacy. The activities have involved 15 students (17-18 years-old) of a Technical School. The contents addressed are: heat, temperature, materials thermal properties. First, an experiment to describe/interpret cooling/heating of a water quantity was done with thermometers and temperature probes; data analysis allowed to identify the mathematical function describing the temperature vs. time trend and the physical parameters of the phenomenon (e.g. conductivity, exchange surface, thickness, etc…). Then, the students were asked to design the walls of an house to met certain temperature requirements in the inner rooms. A prototype “house” with 3 “rooms” separated by “walls” of different materials was built and tested to verify that the materials met the desired requirements when illuminated by an artificial “sun” (high wattage lamp). In each room a sensor measured the temperature. The students drew on the experiment results to investigate the influence of the walls’ material on the heating curve of each room and identify the most suitable materials for walls’ construction. Analysis of answers to an open question shows that the proposed integrated activities improved students’ views about Science and Technology relationships