Top quark electroweak couplings at future lepton colliders

Abstract

We perform a comparative study of the reach of future $e^{+}{e}^{-}$ collider options for the scale of non-resonant new physics effects in the top quark sector, phrased in the language of higher-dimensional operators. Our focus is on the electroweak top quark pair production process $e^{+}{e}^{-}\to Z^{\ast }/\gamma \to t\bar{t}$, and we study benchmark scenarios at the ILC and CLIC. We find that both are able to constrain mass scales up to the few TeV range in the most sensitive cases, improving by orders of magnitude on the forecasted capabilities of the LHC. We discuss the role played by observables such as forward-backward asymmetries, and making use of different beam polarisation settings, and highlight the possibility of lifting a degeneracy in the allowed parameter space by combining top observables with precision $Z$-pole measurements from LEP1.

v1: 11 pages, 11 figures. v2: References added, Fig. 11 updated. Matches version published in EPJC

References in corpus (13)

• The automated computation of tree-level and next-to-leading order differential cross sections, and their matching to parton shower simulations
• The global electroweak fit at NNLO and prospects for the LHC and ILC
• On the Validity of the Effective Field Theory Approach to SM Precision Tests
• A global approach to top-quark flavor-changing interactions
• Probing anomalous Wtb couplings in top pair decays
• Reconstruction of heavy quark current correlators at O(α_s^3)
• Effective Theories and Measurements at Colliders
• Pinning down electroweak dipole operators of the top quark
• Top-quark forward-backward asymmetry in e+e- annihilation at NNLO in QCD
• Electroweak prodution of top-quark pairs in e+e- annihilation at NNLO in QCD: the vector contributions
• NLO QCD Predictions for off-shell $t\bar{t}$ and $t\bar{t}H$ Production and Decay at a Linear Collider
• Giving top quark effective operators a boost
• Two-Parton Contribution to the Heavy-Quark Forward-Backward Asymmetry in NNLO QCD

Cited by in corpus (21)

• The Standard Model as an Effective Field Theory
• A Monte Carlo global analysis of the Standard Model Effective Field Theory: the top quark sector
• The electro-weak couplings of the top and bottom quarks -- global fit and future prospects
• Top and Beauty synergies in SMEFT-fits at present and future colliders
• Global and optimal probes for the top-quark effective field theory at future lepton colliders
• Automated EW corrections with isolated photons: $t\bar{t}\gamma$, $t\bar{t}\gamma \gamma$ and $t\gamma j$ as case studies
• Probing top quark FCNC couplings in the triple-top signal at the high energy LHC and future circular collider
• Measurement of b quark EW couplings at ILC
• New Physics from High Energy Tops
• Effective field theory and scalar extensions of the top quark sector
• Optimal determination of New Physics couplings: A comparative study
• Boosting New Physics Searches in $t\bar{t}Z$ and $tZj$ Production with Angular Moments
• Study of top quark dipole interactions in $t\bar{t}$ production associated with two heavy gauge bosons at the LHC
• Electroweak Top Couplings, Partial Compositeness and Top Partner Searches
• Collider-Flavour Complementarity from the bottom to the top
• Single top production at linear $e^{-}{e}^{+}$ colliders
• Constraining the top quark effective field theory using the top quark pair production in association with a jet at future lepton colliders
• Top quark physics in the Large Hadron Collider era
• Signs of new physics in top quark pair production associated with a neutrino pair at the LHC
• Electroweak radiative corrections to polarized top quark pair production
• Impact of New Physics on Momentum-Dependent Particle Widths and Propagators