NLO QCD corrections to off-shell top–antitop production with semi-leptonic decays at lepton colliders

Ansgar Denner; Mathieu Pellen; Giovanni Pelliccioli

doi:10.1140/epjc/s10052-023-11500-3

2024 Impact factor 4.8

Particles and Fields

Open Access

Eur. Phys. J. C (2023) 83: 353
https://doi.org/10.1140/epjc/s10052-023-11500-3

Regular Article - Theoretical Physics

NLO QCD corrections to off-shell top–antitop production with semi-leptonic decays at lepton colliders

Ansgar Denner¹, Mathieu Pellen² and Giovanni Pelliccioli³^c

¹ Institut für Theoretische Physik und Astrophysik, University of Würzburg, Emil-Hilb-Weg 22, 97074, Würzburg, Germany
² Physikalisches Institut, Universität Freiburg, 79104, Freiburg, Germany
³ Max-Planck-Institut für Physik, Föhringer Ring 6, 80805, Munich, Germany

^c gpellicc@mpp.mpg.de

Received: 15 February 2023
Accepted: 9 April 2023
Published online: 3 May 2023

Abstract

The study of top-quark properties will be a central aspect of the physics programme of any future lepton collider. In this article, we investigate the production of top-quark pairs in the semi-leptonic decay channel in $e^{+} e^{-}$ ${\textrm{e}}^{+}\textrm{e}^{-}$ collisions, whose experimental signature is one charged lepton, jets, and missing energy. We present for the first time fiducial cross sections and differential distributions at next-to-leading-order accuracy in QCD for the full off-shell process. We find that the QCD corrections for the considered process are strongly dependent on the beam energies and range from few per cent up to more than $100 %$ $100\%$ (near threshold and above $1 TeV$ $1\,\text {TeV}$ ). We focus, in particular, on two scenarios: one close to threshold ( $365 GeV$ $365\,\text {GeV}$ ), dominated by top-pair production, and one at the TeV scale ( $1.5 TeV$ $1.5\,\text {TeV}$ ), for which irreducible-background contributions become relevant. An assessment of polarised-beam effects is also provided.

© The Author(s) 2023

Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.