A Search for Rare Decay D0 --> mu+mu - High Energy Physics UPRM

I thank Fanny Mora, my mother, for making me into what I am today. Without herunconditional help I wouldn’t heve gotten to this point. To her above all, I dedicate thistriumph. To my brothers, Madelaine and Jorge Luis, for believing in me and for taking careof my mother while I was absent. To my father Anthony Valle, for always being there inthe good times as well as in the bad times.P U E R TO RICO is a country that I will always have with me. A master’s degree, amarriage and a family. All this I take from you “Isla del Encanto”. I thank my wife Dianafor her unconditional help. Thank you for sharing my good times and my sorrow.An immensurable thanks to the friendship, professional and economic support thatDr. Angel M. López gave me. Thank you for everything you did during the time I workedfor you, and for always believing in me and trusting me. To professors Will E. Johns andHéctor Méndez for helping me out without asking and also to Dr. WeiJun Xiong. Thanksto Dr. Wolfgang Rolke for your cooperation in the statistical analysis for this work. Yourcontribution was of great importance for me. Overall, to all of those who work with me atthe HEP lab at Mayagüez. Those from the past: Alejandro Mirles, Carlos Rivera, MauricioSuárez, Salvador Carrillo, Fabiola Vázquez and Kennie Cruz; and those from the present:José A. Quiñones, Eduardo Luiggi, Alexis París, Luis A. Ninco and Carlos R. Pérez. Thankyou guys!!!To the Physics Department at Mayaguez Campus and its director when I became apart of the University, Dr. Dorial Castellanos (January, 1998), who gave me chance to makeit happen. I that all of those at the FOCUS Collaboration for giving me the opportunityvi