Search For Top Decays Through Flavor Changing Neutral Current Process T Z Q In Pp Collisions At Square Root S

Search for Top Decays Through Flavor Changing Neutral Current Process, T --> Z+q, in Pp Collisions at [square Root]s

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

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%.

Search for the Flavor Changing Neutral Current Decay T $\to Zq$ in $p \bar{p}$ Collisions at $\sqrt{s}

We report a search for the flavor changing neutral current (FCNC) decay of the top quark t → Zq (q = u, c) in p{bar p} collisions at √s = 1.96 TeV using a data sample corresponding to an integrated luminosity of 1.9 fb−1 collected by the CDF II detector. This decay is strongly suppressed in the standard model (SM) and a signal at the Tevatron would be an indication of physics beyond the SM. Using Z+ ≥ 4 jet final state candidate events, both with and without an identified bottom quark jet, we discriminate signal from background by exploring kinematic constraints present in FCNC events and obtain an upper limit of [Beta](t → Zq)