Off-shell effects for t-channel and s-channel single-top production at   NLO in QCD
  In this work we present a calculation of both t-channel and s-channel single-top production at next-to-leading order in QCD for the Tevatron and for the LHC at a centre-of-mass energy of 7 TeV. All the cross sections and kinematical distributions presented include leading non-factorizable corrections arising from interferences of the production and decay subprocesses, extending previous results beyond the narrow-width approximation. The new off-shell effects are found to be generally small, but can be sizeable close to kinematical end-points and for specific distributions. 
P. Falgari, F. Giannuzzi, P. Mellor, A. Signer
hep-ph