Sweet Spot Supersymmetry

TL;DR

This paper proposes a class of supersymmetric theories with GeV-scale gravitinos that naturally resolve multiple longstanding problems, predict a mild hierarchy, and suggest distinctive collider signatures, especially involving long-lived scalar tau particles.

Contribution

It introduces a novel supersymmetric model with GeV gravitinos that addresses flavor, CP, mu, cosmological, and proton decay problems, and provides testable collider predictions.

Findings

No supersymmetric flavor/CP problem in the model

Dark matter explained by non-thermal gravitinos

Scalar tau as long-lived next-to-lightest supersymmetric particle

Abstract

We find that there is no supersymmetric flavor/CP problem, mu-problem, cosmological moduli/gravitino problem or dimension four/five proton decay problem in a class of supersymmetric theories with O(1) GeV gravitino mass. The cosmic abundance of the non-thermally produced gravitinos naturally explains the dark matter component of the universe. A mild hierarchy between the mass scale of supersymmetric particles and electroweak scale is predicted, consistent with the null result of a search for the Higgs boson at the LEP-II experiments. A relation to the strong CP problem is addressed. We propose a parametrization of the model for the purpose of collider studies. The scalar tau lepton is the next to lightest supersymmetric particle in a theoretically favored region of the parameter space. The lifetime of the scalar tau is of O(1000) seconds with which it is regarded as a charged stable particle in collider experiments. We discuss characteristic signatures and a strategy for confirmation of this class of theories at the LHC experiments.