Nnaturalness

TL;DR

This paper proposes a novel solution to the electroweak hierarchy problem by introducing multiple Standard Model copies with varying Higgs masses, leading to a naturally small weak scale and testable cosmological and collider signatures.

Contribution

It introduces a new framework with N copies of the Standard Model to address the hierarchy problem, including cosmological modifications and supersymmetric extensions predicting accessible superpartner masses.

Findings

Reheating favors the lightest sector with a suppressed weak scale.

Current experiments can probe the natural parameter space.

Supersymmetric completions predict superpartners below ~10 TeV.

Abstract

We present a new solution to the electroweak hierarchy problem. We introduce $N$ copies of the Standard Model with varying values of the Higgs mass parameter. This generically yields a sector whose weak scale is parametrically removed from the cutoff by a factor of $1/\sqrt{N}$. Ensuring that reheating deposits a majority of the total energy density into this lightest sector requires a modification of the standard cosmological history, providing a powerful probe of the mechanism. Current and near-future experiments will explore much of the natural parameter space. Furthermore, supersymmetric completions which preserve grand unification predict superpartners with mass below $m_W \times M_{\text{pl}} / M_{\text{GUT}} \sim 10$ TeV.