Münster 2017 – wissenschaftliches Programm
T 18.2: Vortrag
Montag, 27. März 2017, 17:00–17:15, VSH 05
Polarised amplitudes for top quark pair production at NNLO — •Rene Poncelet and Michal Czakon — RWTH Aachen University Institute for Theoretical Particle Physics and Cosmology, Aachen, Germany
More than 20 years after its discovery, the investigation of the top-quark and its properties is in a high-precision phase. The LHC plays a central role in this investigation since it provides a large number of tt-pairs. Precise top-quark measurements are an excellent tool for precision measurements of the Standard Model and searches for new physics. An important ingredient for this kind of measurements are precise theory predictions. Meanwhile, NNLO QCD predictions for tt-pair production at the LHC became available for comparison to data. Inclusive or differential, these predictions have in common that they assume stable top-quarks and use spin-summed matrix-elements. The information about spin-correlations with decay products is therefore lost. I present here the first calculation of amplitudes for production of polarized on-shell tt-pairs at NNLO QCD which is a necessary ingredient to incorporate spin-correlated top-decays in Narrow-Width-Approximation. The full calculation including higher order corrections to the decays can be used to extract the top-quark mass parameter more precisely from the examination of differential distributions of decay products.