Abstract: | The FCC at CERN, a proposed 100-km circular facility with several colliders
in succession, culminates with 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
foresees, as a first step, an Electroweak Factory electron-positron collider.
This high luminosity facility, operating between 90 and 365 GeV centre-of-mass
energy, will study the heavy particles of the Standard Model, Z, W, Higgs, and
top with unprecedented accuracy. 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 had 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, which is reported here, extended the scope to the
next stages, with the production of W-bosons (FCC-ee-W), the Higgs boson
(FCC-ee-H) and top quarks (FCC-ee-tt). In particular, the theoretical precision
in the determination of the crucial input parameters, alpha_QED, alpha_QCD,
M_W, m_t at the level of FCC-ee requirements is thoroughly discussed. The
requirements on Standard Model theory calculations were spelled out, so as to
meet the demanding accuracy of the FCC-ee experimental potential. The
discussion of innovative methods and tools for multi-loop calculations was
deepened. Furthermore, phenomenological analyses beyond the Standard Model were
discussed, in particular the effective theory approaches. |