Solving the Naturalness Problem with Feeble Coupled Sectors

TL;DR

This paper explores a natural solution to the Higgs naturalness problem using feebly coupled sectors, which can include dark matter and neutrino mass mechanisms, and discusses testable predictions within an extended SMEFT framework.

Contribution

It introduces a natural extension of SMEFT incorporating feebly coupled sectors, providing a framework for dark matter and neutrino masses with testable collider signatures.

Findings

Feeble sectors can stabilize the Higgs mass without fine-tuning.

The extended SMEFT predicts small corrections to Higgs properties.

Potential signals for feeble sectors can be tested at future colliders.

Abstract

The discovery of a light Higgs boson means that whatever form new physics takes, it should keep stable the Higgs mass. Besides the well-known solutions to the naturalness problem (Supersymmetry, Conformal symmetry, Compositeness, etc), models that include heavy particles with feeble couplings to the Standard Model (SM) can be considered natural, since the corrections to the Higgs mass remains of the order of the electroweak (EW) scale. This solution can be used for model building too, with realizations that include the see-saw mechanism for neutrino masses and FIMP dark matter models, but it also holds for generic sectors that have Planck-suppressed couplings with the SM. One can also incorporate this solution within the SMEFT framework; the corresponding higher-dimensional operators induce small corrections to both the Higgs mass and its self-coupling, a prediction that can be tested at a future Higgs factory. We present a natural extension of the SMEFT that describes corrections to the SM, while also including a Feeble Coupled Sector aimed to account for the dark cosmos, with predictions for new signals that can be tested too.