https://doi.org/10.1140/epjp/s13360-026-07399-w
Regular Article
Other science opportunities at the FCC-ee
1
Deutsches Elektronen-Synchrotron DESY, Hamburg, Germany
2
Argonne National Laboratory, Lemont, IL, USA
3
European Organization for Nuclear Research (CERN), Geneva, Switzerland
4
A.I. Alikhanyan National Laboratory, Yerevan, Armenia
5
INFN Ferrara, Ferrara, Italy
6
University of Ferrara, Ferrara, Italy
7
PSI, Villigen, Switzerland
8
University of Oslo, Oslo, Norway
9
European XFEL, Hamburg, Germany
10
CEA Irfu, University Paris-Saclay, Gif-sur-Yvette, France
11
ETH Zürich, Zurich, Switzerland
12
University of the Bundeswehr Munich, Neubiberg, Germany
13
INFN Milano, Milan, Italy
14
IJCLab, Orsay, France
15
University Liverpool, Liverpool, UK
16
University of Manchester, Manchester, UK
17
University of Heidelberg, Heidelberg, Germany
18
University of Plymouth, Plymouth, UK
19
LPNHE, Paris, France
20
INFN LNF, Frascati, Italy
21
ENEA, Frascati, Italy
22
University of Geneva, Geneva, Switzerland
23
University Milano, Milan, Italy
24
AGH University, Cracow, Poland
25
EHU Quantum Center and Department of Physics, University of the Basque Country UPV/EHU, Bilbao, Spain
26
IKERBASQUE, Bilbao, Spain
27
Northern Illinois University, DeKalb, USA
28
INFN Roma1, Rome, Italy
29
UCL, London, UK
a
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Received:
19
August
2025
Accepted:
2
February
2026
Published online:
11
March
2026
Abstract
The Future Circular Collider (FCC) integrated programme begins with the FCC-ee, an electron-positron collider, followed by the FCC-hh, a proton–proton collider installed in the same 91 km circumference tunnel near CERN. Spanning 15 years from the mid-to-late 2040s through the early 2060s, the FCC-ee will operate at centre-of-mass energies between approximately 90 and 365 GeV, consistently delivering the highest possible luminosities to four experiments in a sustainable and energy-efficient manner. A key element of its design is top-up injection from a full-energy booster housed in the same 91 km tunnel, along with the world’s most intense positron source and 20 GeV injector linacs. The FCC-ee injector complex, comprising a high intensity positron source, a damping ring, and a linac accelerating electrons and positrons up to 20 GeV, is expected to start operation several years earlier than the booster and the collider. The primary objective of the FCC-ee is its rich High Energy Physics programme based on electron-positron collisions at various centre-of-mass energies (Benedikt et al. in Eur Phys J C 85:1468 https://doi.org/10.1140/epjc/s10052-025-15077-x, 2025). In addition, thanks to its large circumference, high beam energy, abundant positron production, and low-emittance beams, the FCC-ee also offers unique opportunities for various fields of physics and science. These include the potential production of true muonium, the creation of a Bose-Einstein condensate of positronium, Compton imaging with high-energy photons, the generation of spatially coherent photon beams, possibly down to 0.1 Åwavelengths—achieving several orders of magnitude higher average and peak brightness than any existing or planned light source—radioactive isotope production, and an electron- or photon-beam-driven neutron source. We present these and other science exploitations of the FCC-ee accelerator complex.
© The Author(s) 2026
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