Dresden 2013 – scientific programme

Parts | Days | Selection | Search | Updates | Downloads | Help

T: Fachverband Teilchenphysik

T 38: Top-Quarks: Single-Top 1

T 38.5: Talk

Tuesday, March 5, 2013, 17:45–18:00, HSZ-04

Monte Carlo generator comparison for the Wt-channel of single top-quark production — •Pienpen Seema, Ian C. Brock, Irina Cioară, Thomas Loddenkötter, Sebastian Mergelmeyer, and Jan A. Stillings — Physikalisches Institut, University of Bonn

Single top-quark production in the Wt-channel is the second most important production channel at the LHC. At next-to-leading-order (NLO) the problem arises that tt diagrams (with one subsequently decaying top quark) contribute to the Wt channel, such that the NLO corrections are much larger than the LO cross section itself. In order to recover a meaningful definition of the Wt channel at NLO, these contributions therefore have to be removed somehow. This is only possible if there is no interference between the "Wt-like" and the "tt-like" diagrams. In NLO MC generators two different schemes to get rid of the tt-like diagrams are implemented. These are called diagram removal and diagram subtraction. These are designed such that if they yield the same results, one can conclude that the interference is small and therefore the Wt channel is well-defined. Therefore it is important to investigate the differences between different generators.

This contribution will discuss results for Monte Carlo generator comparison for the Wt-channel single top-quark production in the lepton+jets mode in proton-proton collisions at a center-of-mass energy of √s = 8 TeV with the ATLAS detector.