Searches for New Physics in Top Decays at D0
  The Tevatron proton-antiproton collider at Fermilab with its centre of mass energy of 1.96 TeV allows for pair production of top quarks and the study of top quark decay properties. This report reflects the current status of measurements of the W boson helicity in top quark decays and the ratio of top quark branching fractions as well as searches for neutral current top quark decays and pair production of fourth generation t' quarks, performed by the D0 Collaboration utilising datasets of up to 5.4/fb. 
Marc-Andr\'e Pleier
hep-ex