Computation of FCC-ee Sensitivity to Heavy New Physics with Interactions of Any Flavor Structure

TL;DR

This paper introduces a computational tool to evaluate FCC-ee collider sensitivity to heavy new physics interactions, accommodating any flavor structure and incorporating projected experimental and theoretical uncertainties.

Contribution

The paper develops a new tool extending existing software to analyze FCC-ee sensitivity to heavy particles without flavor assumptions, including correlated uncertainties.

Findings

Estimated FCC-ee sensitivity to flavor-specific $Z'$ models.

Demonstrated the tool's application to $b ightarrow s \, \ell^+ \ell^-$ anomalies.

Provided a framework for future collider precision tests.

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 parameterize 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 $Z^\prime$ model with flavor-specific couplings which explains anomalies inferred from present-day measurements and Standard Model predictions of observables that involve the $b \rightarrow s \ell^+ \ell^-$ transition.