title: CERN Yellow Reports: Monographs, Vol 3 (2020): Theory for the FCC-ee: Report on the 11th FCC-ee Workshop, Theory and Experiments, 8–11 January 2019, CERN, Geneva
title: Theory for the FCC-ee: Report on the 11th FCC-ee Workshop, Theory and Experiments, 8–11 January 2019, CERN, Geneva
titleType: AlternativeTitle
Creators: name: CERN
Publisher: name: CERN
Year: 2020

description: Eds. A. Blondel, J. Gluza, S. Jadach, P. Janot and T. Riemann The Future Circular Collider (FCC) at CERN, a proposed 100 km circular facility with several colliders in succession, culminates in a 100 TeV proton–proton collider. It offers a vast new domain of exploration in particle physics, with orders-of-magnitude advances in terms of precision, sensitivity, and energy. The implementation plan published in 2018 foresees, as a first step, an electroweak factory electron– positron collider. This high-luminosity facility, operating at centre-of-mass energies between 90 and 365 GeV, will study the heavy particles of the Standard Model (SM), Z, W, and Higgs bosons, and top quarks with unprecedented accuracy. The physics programme offers great discovery potential: (i) through precision measurements, (ii) through sensitive searches for symmetry violations, forbidden, or extremely rare decays, and (iii) through the search for direct observation of new particles with extremely small couplings. The electroweak factory e+e− collider constitutes a real challenge to the theory and to precision calculations, triggering the need for the development of new mathematical methods and software tools. A first workshop in 2018 focused on the first FCC-ee stage, the Tera-Z, and confronted the theoretical status of precision Standard Model calculations on the Z boson resonance to the experimental demands. The second workshop, in January 2019, extended the scope to the next stages, with the pro- duction of W bosons (FCC-ee-W), the Higgs boson (FCC-ee-H), and top quarks (FCC-ee-tt). In par- ticular, the theoretical precision in the determination of the crucial input parameters, αQED, αQCD, MW, and mt, at the level of FCC-ee requirements was thoroughly discussed. The requirements on Standard Model theory calculations were spelt out, so as to meet the demanding accuracy of the FCC-ee experimental potential. The discussion of innovative methods and tools for multiloop calcu- lations was deepened. Furthermore, phenomenological analyses beyond the Standard Model were dis- cussed, including effective theory approaches. The reports of 2018 and 2019 serve as white papers of the workshop results and subsequent developments.
description: Theoretical luminosity precision for the FCC-ee: overview of the path to 0.01%...65 Editors’ note...viii Contents...xi Executive summary...1 Introduction and overview...3 αQED, eff (s) for precision physics at the FCC-ee/ILC...9 Precision quantum chromodynamics...38 Inclusion of mixed QCD–QED resummation effects at higher orders...51 CoLoRFulNNLO at work: a determination of αS...57 e+e− → γγ at large angles for FCC-ee luminometry...71 Prospects for higher-order corrections to W pair production near threshold in the EFT approach...77 Perspectives of heavy quarkonium production at the FCC-e...89 Vertex functions in QCD—preparation for beyond two loops...97 Effective field theory approach to QED corrections in flavour physics...107 Top pair production and mass determination...117 Higgs boson decays: theoretical status...123 Heritage projects, preservation, and re-usability concerns...135 Scalar one-loop Feynman integrals in arbitrary space–time dimension d – an update...139 NNLO corrections in four dimensions...163 Unsubtractions at NNLO...169 Numerics for elliptic Feynman integrals...177 Numerical multiloop calculations: sector decomposition and QMC integration in pySecDec...185 Analytics from numerics: five-point QCD amplitudes at two loops...193 Recent developments in Kira...201 Precision Monte Carlo simulations with WHIZARD...205 FCC tau polarisation...211 Electron–positron annihilation processes in MCSANCee...213 Global electroweak fit in the FCC-ee era...217 SMEFT...221 (Triple) Higgs coupling imprints at future lepton colliders...231 Exotic Higgs decays (and long-lived particles) at future colliders...241 Precision predictions for Higgs decays in the (N)MSSM...247 Acknowledgements...267