Gamma-ray signals from multicomponent scalar dark matter decays

Abstract

Within a multicomponent dark matter scenario, novel gamma-ray signals may arise from the decay of the heavier dark matter component into the lighter. For a scalar dark sector of this kind, the decay ${\varphi }_2\to {\varphi }_1\gamma$ is forbidden by the conservation of angular momentum, but the decay ${\varphi }_2\to {\varphi }_1\gamma \gamma$ can have a sizable or even dominant branching ratio. In this paper we present a detailed study of this decay channel. We determine the width and photon energy spectrum generated in the decay, employing an effective theory approach, and in UV complete models where the scalar dark matter components interact with heavy or light fermions. We also calculate limits on the inverse width from current data of the isotropic diffuse photon flux, both for a hierarchical and a degenerate dark matter spectrum. Finally, we briefly comment on the prospects of observing the diphoton signal from sneutrino decay in the minimal supersymmetric standard model extended with right-handed neutrino superfields ($\tilde{\nu }$MSSM).

22 pages, 10 figures, Version matches published version

References in corpus (8)

• Dark Matter Candidates from Particle Physics and Methods of Detection
• Gauge Singlet Scalars as Cold Dark Matter
• The spectrum of isotropic diffuse gamma-ray emission between 100 MeV and 820 GeV
• New Gamma-Ray Contributions to Supersymmetric Dark Matter Annihilation
• Dark matter constraints from box-shaped gamma-ray features
• INTEGRAL SPI All-Sky View in Soft Gamma Rays: Study of Point Source and Galactic Diffuse Emissions
• Right-Handed Sneutrino as Cold Dark Matter of the Universe
• Right-handed Sneutrinos as Nonthermal Dark Matter

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• Dark matter candidates in the NMSSM with RH neutrino superfields
• Probing multicomponent FIMP scenarios with gamma-ray telescopes
• Search for decaying heavy dark matter in an effective interaction framework: a comparison of $\gamma$-ray and radio observations
• Prospects for detecting the rare heavy Higgs decay $H\to h\gamma \gamma$ through the $H\to b\bar{b}\gamma \gamma$ channel at the LHC