Search for the Flavor Changing Neutral Current Decay $t\rightarrow qZ$ in $p\overline{p}$ Collisions at $\sqrt{s}$ = 1.96 TeV

Abstract

This dissertation presents a blind search for the flavor changing neutral current decay of the top quark t → qZ in pp collisions at [special characters omitted] = 1.96TeV using a data sample corresponding to an integrated luminosity of 1.12 fb-1 collected by the Collider Detector at Fermilab (CDF), This decay is extremely rare in the standard model, and a signal at the Tevatron would be an indication of new physics. Dividing candidate events with a Z boson and four or more jets into a sample of those which have a heavy flavor jet identified by a secondary vertex algorithm and those which do not, we observe data yields consistent with background expectations. We set a 95% C.L. upper limit on the branching fraction B (t → qZ) of 11.3%, consistent with an expected upper limit of 7.8% ± 3.3%.