Speakers
Aurelio Juste
(Fermilab)
Horst Wahl
(Florida State University)
Stefan Soldner-Rembold
(University of Manchester)
Description
We present the simultaneous measurement of the ratio of branching fractions, R=B(t -> Wb)/B(t -> Wq), with q being a d, s, or b quark, and the top quark pair production cross section sigma(ttbar) in the lepton plus jets channel using data at sqrt(s)=1.96 TeV collected with the D0 detector. We extract R and sigma(ttbar) by analyzing samples of events with 0, 1 and >2 identified b jets.
We also report on a model-independent measurement of the helicity of W bosons
produced in top quark decays based on a 4 fb-1 sample of ttbar events in
the dilepton and lepton+jets channels.
W boson helicity fractions are sensitive to the ratios of different
anomalous Wtb couplings as well as single top production.
We set simultaneous limits on left-handed vector and right-handed vector,
and left-handed vector and right-handed tensor Wtb couplings measured
using the single top selection.
We combined this analysis with the W boson helicity measurement
to set direct upper limits on a right-handed vector coupling as well as a
left-handed tensor coupling.
Authors
Aurelio Juste
(Fermilab)
Horst Wahl
(Florida State University)
Stefan Soldner-Rembold
(University of Manchester)
