a precise characterisation of the top quark electro weak vertices at the ilc

• DOI: 10.48550/arxiv.1505.06020
• Publication Date: 2015-10-01
• Authors: M.S. Amjad; Francois Richard; Roman Pöschl; T. Frisson; J. Rouëné; Marcel Vos; M. Perelló; P. Doublet; P. Doublet; P. Ruiz Femenia; P. Ruiz Femenia; S. Bilokin; Eduardo Ros; M. Boronat; I. Garcia Garcia
• Keywords: Physics and Astronomy (miscellaneous); FOS: Physical sciences; 530; 01 natural sciences; High Energy Physics - Experiment; High Energy Physics - Phenomenology; High Energy Physics - Experiment (hep-ex); High Energy Physics - Phenomenology (hep-ph); [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph]; 0103 physical sciences; [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex]; Engineering (miscellaneous)

Top quark production in the process $e^+e^- \to t\bar{t}$ at a future linear electron positron collider with polarised beams is a powerful tool to determine indirectly the scale of new physics. The presented study, based on a detailed simulation of the ILD detector concept, assumes a centre-of-mass energy of $\sqrt{s}=500\,$GeV and a luminosity of $\mathcal{L}=500\,{\rm fb}^{-1}$ equally shared between the incoming beam polarisations of $\mathcal{P}_{e^-}, \mathcal{P}_{e^+} =\pm0.8,\mp0.3$. Events are selected in which the top pair decays semi-leptonically and the cross sections and the forward-backward asymmetries are determined. Based on these results, the vector, axial vector and tensorial $CP$ conserving couplings are extracted separately for the photon and the $Z^0$ component. With the expected precision, a large number of models in which the top quark acts as a messenger to new physics can be distinguished with many standard deviations. This will dramatically improve expectations from e.g. the LHC for electro-weak couplings of the top quark.<br/>This work is an update of arXiv:1307.8102, minor changes w.r.t. v1 (typos, wrong grammar, incomplete sentences etc.)<br/>