Abstract

The European Strategy Update of 2020 offers the vision of a Higgs Factory followed by a HIgh energy (>100 TeV hadron collider). The most effective realization of this vision is the Future Circular Collider (FCC ee and hh) integral project, to be hosted in a new 100km tunnel around Geneva. The first step, FCC ee, is a Higgs and Electroweak circular e+e- factory, that should start operation shortly after the end of HL-LHC.

Built under the principles developed at the B-factories, FCC -ee offers huge luminosities and special qualities of beam energy calibration at the 100 keV level, and possibly monochromatization for the s-channel Higgs production, which single it out among the Higgs factory projects with a set of unique measurement possibilities.

The full exploitation of these opportunities poses considerable challenges both for detector design and theory, to reduce systematic errors at the level of the available statistics.