DOI 10.1007/s100529900071
Complete calculations of 
and
production
at Tevatron and LHC:
Probing anomalous Wtb couplings
in single-top production
E. Boos1 - L. Dudko1 - T. Ohl2
1 Institute of Nuclear Physics, Moscow State University,
119899 Moscow, Russia
2 Institut für Kernphysik, Darmstadt University of Technology,
Darmstadt, Germany
Received: 3 March 1999 / Published oline: 22 October 2999
Abstract
We present the results of a complete tree-level calculation of the
processes
and
that includes the single-top signal and all
irreducible backgrounds simultaneously. In order to probe the
structure of the Wtb coupling with the highest possible accuracy
and to look for possible deviations from standard model predictions,
we identify sensitive observables and propose an optimal set of cuts
which minimizes the background, as compared to the signal. At the
Large Hadron Collider (LHC),
the single-top and the single-antitop rates are different, and the
corresponding asymmetry yields additional information. The analysis
shows that the sensitivity for anomalous couplings will be improved
at the LHC by a factor of 2-3, as compared to the expectations for the
first measurements at the upgraded Tevatron. Still, the bounds on
anomalous couplings obtained at hadron colliders will remain 2-8
times larger than those from high-energy 
colliders;
however, these will not be available for some time. All basic calculations
have been carried out using the computer package CompHEP. The known
next-to-leading-order corrections to the single-top rate have been
taken into account.
Copyright Springer-Verlag
