Gamma-Rays from Decaying Dark Matter

TL;DR

This paper explores the potential for detecting gamma-rays from decaying dark matter, especially gravitino dark matter, using high-latitude observations to distinguish signals from astrophysical backgrounds.

Contribution

It analyzes the gamma-ray signatures of decaying dark matter, emphasizing the detection strategy at high galactic latitudes and the capabilities of upcoming gamma-ray experiments.

Findings

Decaying dark matter produces a distinct gamma-ray flux at high galactic latitudes.

Upcoming experiments like GLAST and AMS-02 can potentially identify or constrain decaying dark matter.

The gamma-ray signal from decay differs from annihilation, affecting detection strategies.

Abstract

We study the prospects for detecting gamma-rays from decaying Dark Matter (DM), focusing in particular on gravitino DM in R-parity breaking vacua. Given the substantially different angular distribution of the predicted gamma-ray signal with respect to the case of annihilating DM, and the relatively poor (of order 0.1$^\circ$) angular resolution of gamma-ray detectors, the best strategy for detection is in this case to look for an exotic contribution to the gamma-ray flux at high galactic latitudes, where the decaying DM contribution would resemble an astrophysical extra-galactic component, similar to the one inferred by EGRET observations. Upcoming experiments such as GLAST and AMS-02 may identify this exotic contribution and discriminate it from astrophysical sources, or place significant constraints on the mass and lifetime of DM particles.