Crunching Dilaton, Hidden Naturalness

TL;DR

This paper proposes a novel solution to the Higgs naturalness problem by linking the Higgs mass to cosmic stability, predicting a light dilaton that can be tested in future experiments.

Contribution

It introduces a new mechanism where the Higgs VEV is connected to a dilaton in a CFT sector, addressing the hierarchy problem through cosmic crunching and metastable vacua.

Findings

Predicts a light dilaton in the 0.1-10 GeV range.

Part of the parameter space is constrained by B-meson decay measurements.

Future experiments will probe the remaining viable parameter space.

Abstract

We introduce a new approach to the Higgs naturalness problem, where the value of the Higgs mass is tied to cosmic stability and the possibility of a large observable Universe. The Higgs mixes with the dilaton of a CFT sector whose true ground state has a large negative vacuum energy. If the Higgs VEV is non-zero and below $\mathcal{O}({\rm TeV})$, the CFT also admits a second metastable vacuum, where the expansion history of the Universe is conventional. As a result, only Hubble patches with unnaturally small values of the Higgs mass support inflation and post-inflationary expansion, while all other patches rapidly crunch. The elementary Higgs VEV driving the dilaton potential is the essence of our new solution to the hierarchy problem. The main experimental prediction is a light dilaton field in the 0.1-10 GeV range that mixes with the Higgs. Part of the viable parameter space has already been probed by measurements of rare B-meson decays, and the rest will be fully explored by future colliders and experiments searching for light, weakly-coupled particles.