is an great advisor. He usually let me work things out for myself instead of giving me something already done. Special thanks to Dr. Jorge Morn, he was very supportive to the Latino group. Many thanks to our spokespersons, Dr. Deborah Harris and Dr. Kevin McFarland, who have been very nice. To CAPES and CNPQ for the scholarship (2008-2012), the University of Pittsburgh, Department Physics of and Astronomy for my appointment as a Visiting Scholar (2012). Thanks to CBPF administrative sta José de Almeida Ricardo and Elisabete Vicente. To FERMI-LAB administrative sta