Physics case of FCC-ee

Abstract

The physics case for electron-positron beams at the Future Circular Collider (FCC-ee) is succinctly summarized. The FCC-ee core program involves $e^+e^-$ collisions at $\sqrt{s}$ = 90, 160, 240, and 350 GeV with multi-ab$^{-1}$ integrated luminosities, yielding about 10$^{12}$ Z bosons, 10$^{8}$ W$^+$W$^-$ pairs, 10$^{6}$ Higgs bosons and 4$\cdot$10$^{5}$ $t\bar{t}$ pairs per year. The huge luminosities combined with $\cal{100}$ keV knowledge of the c.m. energy will allow for Standard Model studies at unrivaled precision. Indirect constraints on new physics can thereby be placed up to scales $\Lambda_{_{\rm NP}} \approx$ 7 and 100 TeV for particles coupling respectively to the Higgs and electroweak bosons.