https://doi.org/10.1140/epjc/s10052-025-14622-y
Regular Article - Experimental Physics
Search for additional scalar bosons within the Inert Doublet Model in a final state with two leptons at the FCC-ee
1
Physics Department, Imperial College London, Prince Consort Road, SW7 2BW, London, UK
2
Rudjer Boskovic Institute, Bijenicka cesta 54, 10000, Zagreb, Croatia
3
Theoretical Physics Department, CERN, 1211, Geneva 23, Switzerland
a
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b
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Received:
16
May
2025
Accepted:
7
August
2025
Published online:
21
August
2025
We present a search for new scalar bosons predicted by the Inert Doublet Model at an 
machine with centre-of-mass energies 
of 240 and 365 
. Within this model, four additional scalar bosons (
and 
) are predicted. Due to an additional symmetry, the lightest new scalar, here chosen to be H, is stable and provides an adequate dark matter candidate. The search for pair production of the new scalars is investigated in final states with two electrons or two muons, in the context of the future circular collider proposal, FCC-ee. Building on previous studies in the context of the CLIC proposal, this analysis extends the search to detector-level objects, using a parametric neural network to enhance the signal contributions over the Standard Model backgrounds, and sets projected exclusion and discovery contours in the 
vs. 
plane. With a total integrated luminosity of 10.8 (2.7) 
for 
240 (365) , the discovery reach for the model goes up to 
for 
at 240 (365) . For exclusion, almost the entire phase-space available in the vs. plane is expected to be ruled out at 95% CL, reaching up to 
.
© The Author(s) 2025
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