What the study found
The study found that Higgs boson-mediated interactions in the Future Circular Collider's electron-positron mode could produce semi-visible jets, meaning jet-like particle sprays containing both visible and invisible particles. The authors report that these signals can be used to probe a wide range of the dark-sector models they considered.
Why the authors say this matters
The authors conclude that their strategy could improve sensitivity to Higgs boson-induced semi-visible jets and enhance discovery prospects at the Future Circular Collider. They also say it can constrain Higgs boson exotic branching ratios, meaning the fraction of Higgs decays into nonstandard final states, into dark quarks at the permille level.
What the researchers tested
The researchers studied exotic signatures from confining dark sectors in electron-positron collisions at the Future Circular Collider. They assumed the Higgs boson mediates between the Standard Model and the dark sector, then examined semi-visible jets with different invisible fractions, including versions enriched in leptons and photons. They used kinematic selections such as missing energy and a graph neural network jet tagger, a machine learning tool that analyzes relationships inside jets through their substructure.
What worked and what didn't
When the invisible component was large, selections based on kinematic features like missing energy already gave good signal-to-background discrimination. When the invisible fraction was smaller, the signals looked more like Standard Model events, and the graph neural network jet tagger improved sensitivity by using jet substructure differences. The abstract states that the proposed strategy can effectively probe a wide parameter space for the models considered and a variety of signatures.
What to keep in mind
The summary describes only the models and signatures considered in this study, so the results apply to that scope. The abstract does not provide detailed numerical performance measures beyond the stated permille-level constraint on exotic branching ratios.
Key points
- The study examines semi-visible jets from confining dark sectors at the Future Circular Collider.
- The Higgs boson is assumed to mediate interactions between the Standard Model and the dark sector.
- Large missing-energy signals are easier to separate from background than cases with smaller invisible fractions.
- A graph neural network jet tagger improved sensitivity when the signals resembled Standard Model events more closely.
- The authors say the approach can constrain Higgs exotic branching ratios into dark quarks at the permille level.
Disclosure
- Research title:
- Semi-visible jets may probe Higgs-linked dark sectors at FCC-ee
- Authors:
- Cesare Cazzaniga, Annapaola de Cosa, Felix Kahlhoefer, Andrea S. Maria, Roberto Seidita, Emre Sitti
- Institutions:
- ETH Zurich, ETH Zurich, ETH Zurich, ETH Zurich, ETH Zurich, Karlsruhe Institute of Technology, Prediction Systems (United States), University of Zurich
- Publication date:
- 2026-04-28
- OpenAlex record:
- View
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