Recent Result of the AMS-02 Experiment and Decaying Gravitino Dark Matter in Gauge Mediation

TL;DR

This paper explores the possibility that the AMS-02 cosmic-ray positron excess is due to decaying gravitino dark matter within gauge-mediated supersymmetry breaking models, aligning with current experimental constraints.

Contribution

It proposes a viable decaying gravitino dark matter scenario explaining positron excesses compatible with existing collider and astrophysical data.

Findings

Fits AMS-02 positron excess with gravitino decay

Compatible with 126 GeV Higgs and SUSY search limits

Predicts testable signals in electron EDM and muon decay

Abstract

The AMS-02 collaboration has recently reported an excess of cosmic-ray positron fractions, which is consistent with previous results at PAMELA and Fermi-LAT experiments. The result indicates the existence of new physics phenomena to provide the origin of the energetic cosmic-ray positron. We pursue the possibility that the enhancement of the positron fraction is due to the decay of gravitino dark matter. We discuss that such a scenario viably fits into the models in which the soft SUSY breaking parameters are dominantly from gauge-mediation mechanism with superparticle masses of around 10 TeV. Our scenario is compatible with ~126 GeV Higgs boson, negative searches for SUSY particles, and non-observation of anomalous FCNC processes. We also point out that the scenario will be tested in near future by measuring the electric dipole moment of the electron and the lepton flavor violating decay of the muon.