Axino dark matter with R-parity violation and 130 GeV gamma-ray line

TL;DR

This paper proposes that decaying axino dark matter with R-parity violation can account for the 130 GeV gamma-ray line observed in the Galactic center, fitting cosmological and astrophysical constraints.

Contribution

It introduces a model where axino dark matter decay explains the gamma-ray line, with specific parameter ranges for the Peccei-Quinn scale and R-parity violation.

Findings

Axino decay can produce a monochromatic 130 GeV gamma-ray line.

The model's parameters satisfy cosmological and astrophysical constraints.

Branching fraction into photons can be of order one.

Abstract

We show that decaying axino dark matter with R-parity violation can explain the observed excess of the 130GeV gamma-ray line from the Galactic center in the Fermi data. The branching fraction of the axino decay into monochromatic photons can be O(1), and constraints from continuum gamma-rays and the anti-proton flux are ameliorated. The Peccei-Quinn scale of $O(10^{13}-10^{14})$\,GeV and the R-parity violation parameter of $O(10^{-12}-10^{-11})$ are cosmologically favored.