An alternative interpretation for cosmic ray peaks

Abstract

We propose an alternative mechanism based upon dark matter (DM) interpretation for anomalous peak signatures in cosmic ray measurements, assuming an extended dark sector with two DM species. This is contrasted with previous effort to explain various line-like cosmic-ray excesses in the context of DM models where the relevant DM candidate directly annihilates into Standard Model (SM) particles. The heavier DM is assumed to annihilate to an on-shell intermediate state. As the simplest choice, it decays directly into the lighter DM along with an unstable particle which in turn decays to a pair of SM states corresponding to the interesting cosmic anomaly. We show that a sharp continuum energy peak can be readily generated under the proposed DM scenario, depending on dark sector particle mass spectra. Remarkably, such a peak is robustly identified as half the mass of the unstable particle. Furthermore, other underlying mass parameters are analytically related to the shape of energy spectrum. We apply this idea to the two well-known line excesses in the cosmic photon spectrum: 130 GeV gamma-ray line and 3.5 keV X-ray line. Each observed peak spectrum is well-reproduced by theoretical expectation predicated upon our suggested mechanism, and moreover, our resulting best fits provide rather improved chi-square values.

9 pages, 3 figures

References in corpus (11)

• Big-Bang Nucleosynthesis
• Observation of an anomalous positron abundance in the cosmic radiation
• Measurement of the Cosmic Ray e+ plus e- spectrum from 20 GeV to 1 TeV with the Fermi Large Area Telescope
• Updated Search for Spectral Lines from Galactic Dark Matter Interactions with Pass 8 Data from the Fermi Large Area Telescope
• (In)direct Detection of Boosted Dark Matter
• Discovery of a 3.5 keV line in the Galactic Center and a Critical Look at the Origin of the Line Across Astronomical Targets
• Indirect Detection of Dark Matter Using MeV-Range Gamma-Ray Telescopes
• Boosted dark matter signals uplifted with self-interaction
• Galactic 511 keV line from MeV millicharged dark matter
• The X-Ray Line Feature At 3.5 Kev In Galaxy Cluster Spectra
• Warped Graviton "Z + Missing Energy" Signal at Hadron Colliders

Cited by in corpus (7)

• Dark Matter "Collider" from Inelastic Boosted Dark Matter
• Lines and Boxes: Unmasking Dynamical Dark Matter through Correlations in the MeV Gamma-Ray Spectrum
• Boxes, Boosts, and Energy Duality: Understanding the Galactic-Center Gamma-Ray Excess through Dynamical Dark Matter
• Primordial Black Holes as a Factory of Axions: Extragalactic Photons from Axions
• GLIMPSE: Graphene-based super-Light Invisible Matter Particle SEarch
• Energy peaks: a high energy physics outlook
• Polynomial Spectrum of Gamma Ray from Dark Matter