Speaker
Dominic Hirschbuehl
(KIT)
Description
In proton-antiproton collisions at the Tevatron top quarks are
predominantly pair-produced via the strong interaction. However,
the standard model of particle physics also predicts the production
of single top-quarks via electroweak processes where an
off-mass-shell W boson is exchanged either in the s-channel or
the t-channel. Once a signal is established the single-top cross
section will serve as an input to tests of the unitarity of the
CKM mixing matrix.
It is a major challenge to distinguish the single top signal from
significant backgrounds, mainly W production in association with
heavy flavour jets. The CDF collaboration has analyzed a Tevatron
Run II dataset corresponding to 1 fb^{-1} of integrated luminosity.
Advanced analysis techniques including neural networks, matrix
elements and likelihood discriminants are employed to search for the
tiny single-top signal. The results of these multivariate searches
will be presented.
Single-Top analyses are an improtant stepping stone for the Higgs
boson search in the WH channel, since the two processes have the
same experimental signature. Understanding the background rates and
background composition in the W+jets sample using single-top techniques
will be a prerequiste for a successful WH analysis. The talk will
summarize the lessons learned by the single-top analyses and point to
their application in the WH search.
Author
Dominic Hirschbuehl
(KIT)
Co-author
CDF Collaboration
