Why is the Supersymmetry Breaking Scale Unnaturally High?

TL;DR

This paper explores why supersymmetry breaking occurs at a high scale, proposing a connection between the Peccei-Quinn and supersymmetry breaking scales, and discusses implications for dark matter and collider experiments.

Contribution

It introduces a model linking axion-related Peccei-Quinn symmetry breaking with supersymmetry breaking, addressing the high scale of supersymmetry breaking and related phenomenology.

Findings

Supersymmetry breaking scale is at least ~10^12 GeV.

Scalar superpartners are at least ~100 TeV in mass.

Gauginos may be detectable at the LHC and axions at ADMX Phase II.

Abstract

Evidence is mounting that natural supersymmetry at the weak scale is not realized in nature. On the other hand, string theory suggests that supersymmetry may be present at some energy scale, and gauge coupling unification implies that that energy scale may be relatively low. A puzzling question is then why nature would prefer a low, but not completely natural supersymmetry breaking scale. Here we offer one possible explanation, which simultaneously addresses also the strong CP and mu problems. We introduce an axion, and suppose that the Peccei-Quinn and supersymmetry breaking scales are connected. If we further assume that R-parity is not conserved, then the axion is required to be dark matter, and the Peccei-Quinn/supersymmetry breaking scale is required to be at least ~10^12 GeV. Gravity mediation then yields scalar superpartners with masses of at least ~100 TeV. The gauginos are likely to obtain loop-factor suppressed masses through anomaly mediation and higgsino threshold corrections, and thus may be accessible at the LHC. The axion should be probed at phase II of the ADMX experiment, and signs of R-parity violation may be seen in the properties of the gauginos.