Cornering Natural SUSY at a Tera-$Z$ Factory

TL;DR

This paper evaluates the potential of the future Tera-$Z$ collider to indirectly probe natural supersymmetry, emphasizing the importance of precision measurements and theoretical improvements for uncovering MSSM signatures.

Contribution

It provides a comprehensive analysis of how the Tera-$Z$ collider can enhance indirect detection of natural SUSY through Higgs and electroweak precision tests, focusing on specific MSSM sectors.

Findings

Tera-$Z$ offers greater sensitivity than Mega-$h$ for MSSM detection.

Precision measurements are crucial for probing natural SUSY.

Reducing Standard Model uncertainties enhances discovery prospects.

Abstract

The future circular $e^+ e^-$ collider (FCC-ee) stands out as the next flagship project in particle physics, dedicated to uncovering the microscopic origin of the Higgs boson. In this context, we assess indirect probes of the Minimal Supersymmetric Standard Model (MSSM), a well-established benchmark hypothesis, exploring the complementarity between Higgs measurements and electroweak precision tests at the $Z$-pole. We study three key sectors: the heavy Higgs doublet, scalar top partners, and light gauginos and higgsinos, focusing on the parameter space favored by naturalness. Remarkably, the Tera-$Z$ program consistently offers significantly greater indirect sensitivity than the Mega-$h$ run. While promising, these prospects hinge on reducing SM uncertainties. Accordingly, we highlight key precision observables for targeted theoretical work.