Cosmological Selection of Multi-TeV Supersymmetry

TL;DR

This paper proposes a cosmological selection mechanism involving discrete R-symmetry and gaugino condensation to explain why superparticles might naturally have multi-TeV masses, aligning with current experimental constraints.

Contribution

It introduces a novel cosmological selection effect that accounts for multi-TeV superparticle masses through R-symmetry breaking and inflationary scale considerations.

Findings

Superparticle masses in the multi-TeV range can be natural due to cosmological effects.

The dynamical scale must exceed the inflationary Hubble scale to avoid domain walls.

Future CMB measurements could test the proposed scenario.

Abstract

We discuss a possible answer to the fundamental question of why nature would actually prefer low-scale supersymmetry, but end up with a supersymmetry scale that is not completely natural. This question is inevitable if we postulate that low-energy supersymmetry is indeed realized in nature, despite the null observation of superparticles below a TeV at the Large Hadron Collider. As we argue in this paper, superparticles masses in the multi-TeV range can, in fact, be reconciled with the concept of naturalness by means of a cosmological selection effect--a selection effect based on the assumption of an exact discrete R-symmetry that is spontaneously broken by gaugino condensation in a pure supersymmetric Yang-Mills theory. In such theories, the dynamical scale of the Yang-Mills gauge interactions is required to be higher than the inflationary Hubble scale, in order to avoid the formation of domain walls. This results in a lower limit on the superparticle masses and leads us to conclude that, according to the idea of naturalness, the most probable range of superparticle masses is potentially located at the multi-TeV, if the inflationary Hubble rate is of O(10^{14}) GeV. Our argument can be partially tested by future measurements of the tensor fraction in the Cosmic Microwave Background fluctuations.