University of Pennsylvania
Department of Physics and Astronomy
High Energy Physics Seminar

Abstract

As performance improves at the world's highest energy collider (the Tevatron) and luminosity increases, the importance of an efficient trigger system becomes more evident. The Collider Detector at Fermilab (CDF) has a complex but flexible trigger system that allows it to wisely select events of physics interest from a collision rate of several MHz. Since the beginning of Run II, CDF's three level trigger system has provided physics data to the experiment in a reliable and efficient manner. More importantly it is the system's flexibility that allows this performance to continue even with the challenges presented by the Tevatron's high luminosity environment. In the first part of this seminar I will present an overview of the relevance of a trigger system to the hadron collider environment and give a description of CDF's system and its performance. After 4 years of taking data for Run II, CDF has enough statistics to attempt to measure the top quark's charge for the first time. A question could then be raised. Is the particle discovered at Fermilab in 1995 truly the Standard Model (SM) top quark? The SM predicts the top quark charge to be +2/3 but an alternative interpretation allows for the discovered particle to be an exotic quark with a charge -4/3. During the last part of my talk I will present a method for measuring the sign of the top quark's charge via its decay products and placing a limit on the likelihood of our data being consistent with the SM.