Gauge hierarchy and metastability from Higgs-driven crunching

TL;DR

This paper proposes a novel solution to the Higgs hierarchy problem by using a landscape mechanism where patches with natural Higgs mass undergo a cosmological crunch, leaving only the metastable patches consistent with our universe.

Contribution

It introduces a new dynamical vacuum selection mechanism based on cosmological crunching to address the Higgs hierarchy problem, linking it to new physics at the TeV scale.

Findings

The mechanism naturally favors patches with the observed Higgs mass.

Proposed models can be tested at future colliders like FCC-ee or muon colliders.

The scenario connects Higgs stability with cosmological evolution and new TeV-scale physics.

Abstract

We present a new solution to the Higgs hierarchy problem based on dynamical vacuum selection in a landscape scanning the Higgs mass. In patches where the Higgs mass parameter takes a natural value, the Higgs potential only admits a minimum with a large and negative energy density. This causes a cosmological crunch, removing such patches from the landscape. Conversely, in patches where the Higgs mass parameter is smaller than a critical value, the Higgs potential admits a metastable minimum with the standard cosmological history. This critical value is determined by the instability scale, where the quartic coupling turns negative due to its running. The ability of this mechanism to explain the observed Higgs mass hinges on new physics at the TeV scale, such as vector-like fermions. We study two simple realizations of this scenario in a heavy neutral lepton model and in the singlet-doublet model, the latter mimicking a Higgsino-bino system. We show that the relevant parts of their parameter spaces can be probed by proposed future colliders, such as the FCC-ee or a muon collider.