New Physics Reach through Precision at Future Colliders: a Multi-Pronged Approach

TL;DR

This paper evaluates the potential of future colliders to detect new physics via precision measurements, using multiple theoretical frameworks and providing an open-source analysis tool.

Contribution

It introduces comprehensive sensitivity projections for future colliders across various EFT frameworks and releases an open-source tool for analysis.

Findings

Future colliders can significantly constrain new physics models.

SMEFT analysis includes NLO corrections and RG evolution.

Open-source SMEFiT framework enables reproducibility and extension.

Abstract

We present projections for the sensitivity of future high-energy colliders to new physics through precision measurements of the Standard Model (SM) interactions, focusing on near-term electron-positron facilities: FCC-ee, LEP3, and the Linear Collider Facility. We interpret these projections in three complementary frameworks: Higgs coupling modifiers, effective Higgs and electroweak couplings, and global SMEFT fits. The SMEFT analysis includes renormalisation-group evolution, linear/quadratic contributions, and NLO corrections to EFT cross sections where available. By matching the EFT to UV-complete models, we also quantify the sensitivity of future colliders to representative benchmark scenarios, including composite Higgs models and single-particle SM extensions. In parallel, we release an updated version of the open-source SMEFiT framework, enabling the results presented here to be fully reproduced, extended, and customised.