A precise characterisation of the top quark electro-weak vertices at the ILC
M.S. Amjad (COMSATS Institute of Information Technology, Islamabad, Pakistan, Laboratoire de l’Accélérateur Linéaire (LAL), Centre Scientifique d’Orsay, BP 34, Bâtiment 200, 91898, Orsay Cedex, France); S. Bilokin (Laboratoire de l’Accélérateur Linéaire (LAL), Centre Scientifique d’Orsay, BP 34, Bâtiment 200, 91898, Orsay Cedex, France); M. Boronat (IFIC, Universitat de Valencia CSIC, c/Catedrático José Beltrán, 2, 46980, Paterna, Spain); P. Doublet (IFIC, Universitat de Valencia CSIC, c/Catedrático José Beltrán, 2, 46980, Paterna, Spain, IUT d’Orsay, Université Paris-Sud, Orsay Cedex, France); T. Frisson (CERN, 1211, Geneva 23, Switzerland, Laboratoire de l’Accélérateur Linéaire (LAL), Centre Scientifique d’Orsay, BP 34, Bâtiment 200, 91898, Orsay Cedex, France); et al - Show all 13 authors
Top quark production in the process e+e-âtt¯ 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 s=500  GeV and a luminosity of L=500fb-1 equally shared between the incoming beam polarisations of Pe-,Pe+=±0.8,â0.3 . Events are selected in which the top pair decays semi-leptonically and the cross sections and the forwardâbackward asymmetries are determined. Based on these results, the vector, axial vector and tensorial CP conserving couplings are extracted separately for the photon and the Z0 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.
