Mapping the SMEFT at High-Energy Colliders: from LEP and the (HL-)LHC to the FCC-ee

TL;DR

This paper updates the global SMEFT analysis incorporating recent LHC data and projections for future colliders like FCC-ee and CEPC, assessing their potential to constrain new physics models.

Contribution

It introduces SMEFiT3.0, a comprehensive framework for analyzing collider data within SMEFT, including novel electroweak precision observable calculations and collider projections.

Findings

Significant constraints on SMEFT parameters from current LHC data.

Projected improvements in parameter constraints with HL-LHC and future colliders.

Demonstrated the impact of FCC-ee and CEPC measurements on UV-complete models.

Abstract

We present SMEFiT3.0, an updated global SMEFT analysis of Higgs, top quark, and diboson production data from the LHC complemented by electroweak precision observables (EWPOs) from LEP and SLD. We consider recent inclusive and differential measurements from the LHC Run II, alongside with a novel implementation of the EWPOs based on independent calculations of the relevant EFT contributions. We estimate the impact of HL-LHC measurements on the SMEFT parameter space when added on top of SMEFiT3.0, through dedicated projections extrapolating from Run II data. We quantify the significant constraints that measurements from two proposed high-energy circular $e^+e^-$ colliders, the FCC-ee and the CEPC, would impose on both the SMEFT parameter space and on representative UV-complete models. Our analysis considers projections for the FCC-ee and the CEPC based on the latest running scenarios and includes $Z$-pole EWPOs, fermion-pair, Higgs, diboson, and top quark production, using optimal observables for both the $W^+W^-$ and the $t\bar{t}$ channels. The framework presented in this work may be extended to other future colliders and running scenarios, providing timely input to ongoing studies towards future high-energy particle physics facilities.