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  • Open Access

Computation of FCC-ee sensitivity to heavy new physics with interactions of any flavor structure

Ben Allanach* and Eetu Loisa†

  • *Contact author: ben.allanach.work@gmail.com
  • †Contact author: eal47@cam.ac.uk
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Phys. Rev. D 112, 075045 – Published 24 October, 2025

DOI: https://doi.org/10.1103/tnrg-x4xj

Abstract

We present a tool to compute the sensitivity of the Future Circular Electron-Positron Collider (FCC-ee) to the interactions of new, heavy particles via publicly available extensions to the smelli and flavio computer programs. We parametrize new particles’ effects without any flavor assumptions and take into account the projected experimental and correlated theoretical uncertainties of various electroweak and Higgs observables at the proposed collider. We illustrate a use of the tool by estimating the sensitivity of the FCC-ee to a Z′ model with flavor-specific couplings, which explains anomalies inferred from present-day measurements and Standard Model predictions of observables that involve the b→sℓ+ℓ− transition.

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Outline

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Phys. Rev. D 112, 075045– Published 24 October, 2025
  • Received 27 January 2025
  • Revised 21 July 2025
  • Accepted 6 October 2025
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