Gravitational Gauge Mediation
Ryuichiro Kitano
TL;DR
The paper addresses the challenge that gauge mediation with a messenger sector can favor a SUSY-preserving vacuum and proposes gravity as a stabilization mechanism for a metastable SUSY-breaking vacuum. It shows that supergravity corrections split the SUSY-breaking and SUSY-preserving minima, allowing a metastable minimum at $S \sim \tilde{\Lambda}^2 / M_{\rm Pl}$ for $\tilde{\Lambda} \gtrsim 10^{13}$ GeV, with a SUSY minimum near the origin; stability depends on parameters such as $\kappa$ and the scale $\tilde{\Lambda}$, and phenomenology ties $\mu^2$ to electroweak scales and yields $m_{3/2}$ in the GeV range. The work also discusses ultraviolet completions, including O'Raifeartaigh-type and IYIT models, connecting $\tilde{\Lambda}$ to dynamical scales and showing how the MSSM $\mu$-parameter can emerge from the SUSY-breaking sector. Overall, gravitational stabilization offers a robust mechanism to realize metastable SUSY breaking in gravity-augmented gauge mediation across a wide class of theories, with testable implications for gaugino and gravitino masses and potential links to the cosmological constant term.
Abstract
It is often the case that the naive introduction of the messenger sector to supersymmetry breaking models causes restoration of supersymmetry. We discuss a possibility of stabilizing the supersymmetry breaking vacuum by gravitational interaction.