We search for pair production of the supersymmetric partner of the top quark, the stop quarkt 1 , decaying to a b-quark and a charginoχ ± 1 with a subsequentχ ± 1 decay into a neutralinoχ 0 1 , lepton , and neutrino ν. Using 2.7 fb −1 of √ s = 1.96 TeV pp collision data collected by the CDF II experiment, we reconstruct the mass of candidate stop events and fit the observed mass spectrum to a combination of standard model processes and stop signal. No evidence oft 1t1 production is found, therefore we set 95% C.L. limits on the masses of the stop and the neutralino for several values of the chargino mass and the branching ratio B χ ± 1 →χ 0 1 ± ν. 0.1. ACKNOWLEDGMENTS vi I am also thankful to all of my friends who have understood when I couldn't spend time with them, or attend their parties because of school. I am especially thankful to my good friends and rock climbing partners David Cherney and Lisa Hardy. The many trips rock climbing with these two helped me to remain sane the first two years of grad school. Starting from community college, David was perhaps the greatest influence in shaping my philosophy of and approach towards science; Lisa not only showed me how impressive the human intellect can be, but also at one point physically forced me to staying in grad school, when I otherwise wouldn't have. I am most thankful to my family. My parents have selflessly sacrificed so much, and worked so hard to provide my sibling and I with the best opportunities they could. They unknowingly conditioned me to pursue physics when I was young, encouraged me through college, and were always there for me in grad school, even though I don't think we knew or understood where it would go or what it could be useful for. For my families unconditional love, I will always be grateful. 0.2. INTRODUCTION vii 0.2. Introduction The research in this thesis was performed from August 2006 though May 2009, by Andrew Ivanov, Robin Erbacher and the author. The results represent the effort of a much larger group of people however. The accelerator division at Fermilab who run the Tevatron to give the D0 and CDF experiments their data. The people at CDF who built the detector, who run the online system to collect the data, who perform offline calibrations, data handling, computing support, software creation, and much more. This research also benefited from the techniques and tools pioneered by the researchers before us, which made this this analysis possible. Additionally, many people at CDF contributed to this analysis by helping to review it's integrity, as well as suggest improvements.