Multi-Step Cascade Annihilations of Dark Matter and the Galactic Center Excess

Abstract

If dark matter is embedded in a non-trivial dark sector, it may annihilate and decay to lighter dark-sector states which subsequently decay to the Standard Model. Such scenarios - with annihilation followed by cascading dark-sector decays - can explain the apparent excess GeV gamma-rays identified in the central Milky Way, while evading bounds from dark matter direct detection experiments. Each 'step' in the cascade will modify the observable signatures of dark matter annihilation and decay, shifting the resulting photons and other final state particles to lower energies and broadening their spectra. We explore, in a model-independent way, the effect of multi-step dark-sector cascades on the preferred regions of parameter space to explain the GeV excess. We find that the broadening effects of multi-step cascades can admit final states dominated by particles that would usually produce too sharply peaked photon spectra; in general, if the cascades are hierarchical (each particle decays to substantially lighter particles), the preferred mass range for the dark matter is in all cases 20-150 GeV. Decay chains that have nearly-degenerate steps, where the products are close to half the mass of the progenitor, can admit much higher DM masses. We map out the region of mass/cross-section parameter space where cascades (degenerate, hierarchical or a combination) can fit the signal, for a range of final states. In the current work, we study multi-step cascades in the context of explaining the GeV excess, but many aspects of our results are general and can be extended to other applications.

arXiv comment18 pages, 15 figures, 2 tables; comments welcome. Updated to published version

References in corpus (45)

• A Universal Density Profile from Hierarchical Clustering
• The Structure of Cold Dark Matter Halos
• A Brief Introduction to PYTHIA 8.1
• A Theory of Dark Matter
• First results from the LUX dark matter experiment at the Sanford Underground Research Facility
• Secluded WIMP Dark Matter
• Dark Matter Annihilation in The Galactic Center As Seen by the Fermi Gamma Ray Space Telescope
• Muon Decay and Physics Beyond the Standard Model
• Non-Perturbative Effect on Dark Matter Annihilation and Gamma Ray Signature from Galactic Center
• Astrophysical Signatures of Secluded Dark Matter
• On The Origin Of The Gamma Rays From The Galactic Center
• Detection of a Gamma-Ray Source in the Galactic Center Consistent with Extended Emission from Dark Matter Annihilation and Concentrated Astrophysical Emission
• CMB Constraints on WIMP Annihilation: Energy Absorption During the Recombination Epoch
• Background model systematics for the Fermi GeV excess
• Explosive Dark Matter Annihilation
• Dark Matter and Pulsar Model Constraints from Galactic Center Fermi-LAT Gamma Ray Observations
• Particle decays during the cosmic dark ages
• Astrophysical and Dark Matter Interpretations of Extended Gamma-Ray Emission from the Galactic Center
• Detecting Dark Matter Annihilation with CMB Polarization : Signatures and Experimental Prospects
• Spin determination of single-produced resonances at hadron colliders
• Non-Abelian Dark Sectors and Their Collider Signatures
• LHC Signals for a SuperUnified Theory of Dark Matter
• New limits on dark matter annihilation from AMS cosmic ray positron data
• Simplified Dark Matter Models for the Galactic Center Gamma-Ray Excess
• Dark Matter through the Axion Portal
• A Renormalizable Model for the Galactic Center Gamma Ray Excess from Dark Matter Annihilation
• Heavy Dark Matter Through the Higgs Portal
• The Consistency of Fermi-LAT Observations of the Galactic Center with a Millisecond Pulsar Population in the Central Stellar Cluster
• Current Dark Matter Annihilation Constraints from CMB and Low-Redshift Data
• A comment on the emission from the Galactic Center as seen by the Fermi telescope
• Cosmic Ray Protons in the Inner Galaxy and the Galactic Center Gamma-Ray Excess
• Pulsars Cannot Account for the Inner Galaxy's GeV Excess
• Hidden On-Shell Mediators for the Galactic Center Gamma-Ray Excess
• Fitting the Galactic Center Gamma-Ray Excess with Cascade Annihilations
• Galactic Center gamma-ray "excess" from an active past of the Galactic Centre?
• Higgs portal vector dark matter for $\mathrm{GeV}$ scale $\gamma$-ray excess from galactic center
• The Contribution of Cosmic Rays Interacting With Molecular Clouds to the Galactic Center Gamma-Ray Excess
• The Effective Hooperon
• Dark Matter Signals from Cascade Annihilations
• NMSSM Interpretation of the Galactic Center Excess
• Lepton Jets in (Supersymmetric) Electroweak Processes
• Phenomenology of Dark Matter annihilation into a long-lived intermediate state
• Galactic Center Gamma-Ray Excess through a Dark Shower
• A Simple Recipe for the 111 and 128 GeV Lines
• Sharper Fermi LAT Images: instrument response functions for an improved event selection

Cited by in corpus (70)

• GeV-Scale Thermal WIMPs: Not Even Slightly Dead
• Gamma-ray Constraints on Decaying Dark Matter and Implications for IceCube
• Model-Independent Indirect Detection Constraints on Hidden Sector Dark Matter
• Dark Matter's secret liaisons: phenomenology of a dark U(1) sector with bound states
• Powerful Solar Signatures of Long-Lived Dark Mediators
• Stealth Dark Matter: Dark scalar baryons through the Higgs portal
• Indirect Detection of Neutrino Portal Dark Matter
• The High-Energy Tail of the Galactic Center Gamma-Ray Excess
• Gamma-rays from Dark Showers with Twin Higgs Models
• Secluded singlet fermionic dark matter driven by the Fermi gamma-ray excess
• Searching for Secluded Dark Matter with H.E.S.S., Fermi-LAT, and Planck
• Mapping Extragalactic Dark Matter Annihilation with Galaxy Surveys: A Systematic Study of Stacked Group Searches
• Multimediator models for the galactic center gamma ray excess
• Scalar dark matter, Type II Seesaw and the DAMPE cosmic ray $e^{+}+e^{-}$ excess
• Unsupervised Hadronic SUEP at the LHC
• $Z^{\prime }$ Mediated WIMPs: Dead, Dying, or Soon to be Detected?
• The Thermal History of Composite Dark Matter
• Dark Forces in the Sky: Signals from Z' and the Dark Higgs
• Antiprotons from dark matter annihilation through light mediators and a possible excess in AMS-02 $\bar{p}/p$ data
• The Semi-Hooperon: Gamma-ray and anti-proton excesses in the Galactic Center
• Sensitivity of the Cherenkov Telescope Array to the detection of a dark matter signal in comparison to direct detection and collider experiments
• The One-Loop Correction to Heavy Dark Matter Annihilation
• Radiative Neutrino Mass with $Z_3$ Dark matter: From Relic Density to LHC Signatures
• p-wave Annihilating Dark Matter from a Decaying Predecessor and the Galactic Center Excess
• Constraints on box-shaped cosmic ray electron feature from dark matter annihilation with the AMS-02 and DAMPE data
• Point Sources from Dissipative Dark Matter
• Boxes, Boosts, and Energy Duality: Understanding the Galactic-Center Gamma-Ray Excess through Dynamical Dark Matter
• A Systematic Study of Hidden Sector Dark Matter: Application to the Gamma-Ray and Antiproton Excesses
• Hadronic Footprint of GeV-Mass Dark Matter
• Toward the ultimate reach of current imaging atmospheric Cherenkov telescopes and their sensitivity to TeV dark matter
• Indirect searches for dark matter bound state formation and level transitions
• Search for a dark-matter induced Cosmic Axion Background with ADMX
• Dark Higgs Channel for FERMI GeV $\gamma$-ray Excess
• Lepton-Flavor Violating Mediators
• Dark Matter, Shared Asymmetries, and Galactic Gamma Ray Signals
• Simple Hidden Sector Dark Matter
• Constraints on dark matter with future MeV gamma-ray telescopes
• Leptoquarks and Real Singlets: A Richer Scalar Sector Behind the Origin of Dark Matter
• Hazma Meets HERWIG4DM: Precision Gamma-Ray, Neutrino, and Positron Spectra for Light Dark Matter
• MeV to multi-TeV thermal WIMPs: most conservative limits
• Thermodynamic Evolution of Secluded Vector Dark Matter: Conventional WIMPs and Nonconventional WIMPs
• Right-Handed Neutrino Dark Matter with Forbidden Annihilation
• Interpreting the galactic center gamma-ray excess in the NMSSM
• Secluded Dark Matter in light of the Cherenkov Telescope Array (CTA)
• Cosmic Ray Antihelium from a Strongly Coupled Dark Sector
• Explanation of the 511 keV line: Cascade annihilating dark matter with the ${}^8$Be anomaly
• Type II Seesaw with scalar dark matter in light of AMS-02, DAMPE and Fermi-LAT
• The Galactic Center Excess from Z3 Scalar Semi-Annihilations
• Non-adiabatic evolution of dark sector in the presence of $U(1{)}_{L_{\mu }-L_{\tau }}$ gauge symmetry
• Simplified dark matter models in the light of AMS-02 antiproton data
• Revisiting simplified dark matter models in terms of AMS-02 and Fermi-LAT
• Search for soft unclustered energy patterns in proton-proton collisions at 13 TeV
• Indirect Detection of Secluded Supersymmetric Dark Matter
• Search for Scalar Dark Matter via Pseudoscalar Portal Interactions: In Light of the Galactic Center Gamma-Ray Excess
• Present and Future constraints on Secluded Dark Matter in the Galactic Halo with TeV Gamma-ray Observatories
• Phenomenology of Colored Radiative Neutrino Mass Model and Its Implications on the Cosmic-ray Observations
• Quantum Simulations of Dark Sector Showers
• Bouncing Dark Matter
• A Potentially Detectable Gamma-Ray Line in the Fermi Galactic Center Excess -- In Light of One-Step Cascade Annihilations of Secluded (Vector) Dark Matter via the Higgs Portal
• Dark Matter Annihilation via Breit-Wigner Enhancement with Heavier Mediator
• Some Implications of the Leptonic Annihilation of Dark Matter: Possible Galactic Radio Emission Signatures and the Excess Radio Flux of Extragalactic Origin
• Axion Portal to Scalar Dark Matter: Unveiling Stabilizing Symmetry Footprints
• Flux-mediated Dark Matter
• When Freeze-out occurs due to a non-Boltzmann suppression: A study of degenerate dark sector
• Prospects for the detection of Dark Matter with Long-lived Mediators in the Sun using the Southern Wide-field Gamma-ray Observatory
• Directional Direct Detection of MeV Scale Boosted Dark Matter in Two Component Dark Matter Scenario via Dark Photon Interaction
• Composite asymmetric dark matter with a dark photon portal: Multimessenger tests
• Indirect Searches for Secluded Dark Matter
• Constraining light dark matter in vector-scalar portals with COSI and AMEGO-X
• Extragalactic Searches for Dark Matter Annihilation