Indirect constraints on top quark operators from a global SMEFT analysis

TL;DR

This paper conducts a comprehensive, model-independent SMEFT analysis to derive indirect constraints on top quark operators by combining diverse low-energy measurements and comparing them with direct LHC bounds.

Contribution

It introduces a global SMEFT framework considering only top-quark operators at tree level, integrating multiple observables and RG evolution for the first time.

Findings

Strong interplay among different observables constrains top operators.

Complementarity between low-energy and collider bounds is demonstrated.

Constraints are applied to specific ultraviolet models.

Abstract

We perform a model-independent analysis of top-philic New Physics scenarios, under the assumption that only effective operators involving top quarks are generated at tree level. Within the SMEFT framework, we derive indirect constraints on Wilson Coefficients by combining a large set of low-energy observables: B-meson and kaon decays, meson mixing observables, precision electroweak and Higgs measurements, anomalous magnetic moments, lepton flavour violating processes, lepton flavour universality tests, and measurements of the Cabibbo angle. We consider the renormalization group evolution of the operators and use the one-loop matching of the SMEFT onto the LEFT. The global analysis is then used to perform one-parameter, two-parameter, and global fits, as well as applications to explicit ultraviolet models. We find that the inclusion of measurements from different physics sectors reveals a strong interplay and complementarity among the observables. The resulting constraints are also compared to direct bounds provided by top quark productions at the LHC.