4 documents found, page 1 of 1
As masterclasses internacionais em física de partículas em Portugal
Abreu, P.; Abreu, M.C.; Barão, F.; Bertolami, O.; Castro, N.; Espírito Santo, C.; Mota, M.F.; Naia, M.D.; Onofre, A.; Peralta, L.; Pereira, Ana I.Todos os anos, desde 2005, institutos de investigação e universidades de todo o mundo convidam estudantes do ensino secundário a experimentar a linha da frente da investigação fundamental. São as Masterclasses Internacionais em Física de Partículas, um programa do International Particle Physics Outreach Group (IPPOG) que oferece aos estudantes a oportunidade de serem cientistas por um dia, analisando dados reai...
Measurement of the electron structure function F$\frac{e}{2}$ at LEP energies
DELPHI collaboration (343 authors); Abreu, P.; Andringa, S.; Anjos, N.; Castro, N.; De Angelis, A.; Espirito Santo, M.C.; Gonçalves, P.; Onofre, A.The hadronic part of the electron structure function F2e has been measured for the first time, using e+e− data collected by the DELPHI experiment at LEP, at centre-of-mass energies of s=91.2–209.5 GeV . The data analysis is simpler than that of the measurement of the photon structure function. The electron structure function F2e data are compared to predictions of phenomenological models based on the photon str...
Search for Charged Higgs bosons: Combined Results Using LEP Data
ALEPH, DELPHI, L3, OPAL, LEP collaboration (1216 authors); Abreu, P.; Andringa, S.; Anjos, N.; Castro, Nuno Filipe; De Angelis, A.; Espirito Santo, M.C.The four LEP collaborations, ALEPH, DELPHI, L3 and OPAL, have searched for pair-produced charged Higgs bosons in the framework of Two Higgs Doublet Models (2HDMs). The data of the four experiments are statistically combined. The results are interpreted within the 2HDM for Type I and Type II benchmark scenarios. No statistically significant excess has been observed when compared to the Standard Model background ...
Clear-PEM: A PET imaging system dedicated to breast cancer diagnostics
Abreu, M. C.; Aguiar, D.; Albuquerque, E.; Almeida, F. G.; Almeida, P.; Amaral, P.; Auffray, E.; Bento, P.; Bruyndonckx, P.; Bugalho, R.; Carriço, B.The Clear-PEM scanner for positron emission mammography under development is described. The detector is based on pixelized LYSO crystals optically coupled to avalanche photodiodes and readout by a fast low-noise electronic system. A dedicated digital trigger (TGR) and data acquisition (DAQ) system is used for on-line selection of coincidence events with high efficiency, large bandwidth and small dead-time. A sp...