Gamma-ray lines and One-Loop Continuum from s-channel Dark Matter Annihilations

Abstract

The era of indirect detection searches for dark matter has begun, with the sensitivities of gamma-ray detectors now approaching the parameter space relevant for weakly interacting massive particles. In particular, gamma ray lines would be smoking gun signatures of dark matter annihilation, although they are typically suppressed compared to the continuum. In this paper, we pay particular attention to the 1-loop continuum generated together with the gamma-ray lines and investigate under which conditions a dark matter model can naturally lead to a line signal that is relatively enhanced. We study generic classes of models in which DM is a fermion that annihilates through an s-channel mediator which is either a vector or scalar and identify the coupling and mass conditions under which large line signals occur. We focus on the "forbidden channel mechanism" advocated a few years ago in the "Higgs in space" scenario for which tree level annihilation is kinematically forbidden today. Detailed calculations of all 1-loop annihilation channels are provided. We single out very simple models with a large line over continuum ratio and present general predictions for a large range of WIMP masses that are relevant not only for Fermi and Hess II but also for the next generation of telescopes such as CTA and Gamma-400. Constraints from the relic abundance, direct detection and collider bounds are also discussed.

32 pages, 13 figures; v2: minor clarifications, summary paragraph added; v3: matches published version, minor clarifications, results unchanged

References in corpus (23)

• A Tentative Gamma-Ray Line from Dark Matter Annihilation at the Fermi Large Area Telescope
• Beyond the Minimal Composite Higgs Model
• Fermi LAT Search for Dark Matter in Gamma-ray Lines and the Inclusive Photon Spectrum
• Top Compositeness at the Tevatron and LHC
• Manifestations of Top Compositeness at Colliders
• What if Dark Matter Gamma-Ray Lines come with Gluon Lines?
• Extra U(1) as natural source of a monochromatic gamma ray line
• Is the 130 GeV Line Real? A Search for Systematics in the Fermi-LAT Data
• Two Lines or Not Two Lines? That is the Question of Gamma Ray Spectra
• The WIMP Forest: Indirect Detection of a Chiral Square
• Implications of a 130 GeV Gamma-Ray Line for Dark Matter
• Three Exceptions for Thermal Dark Matter with Enhanced Annihilation to Gamma Gamma
• Illuminating the 130 GeV Gamma Line with Continuum Photons
• An evidence for indirect detection of dark matter from galaxy clusters in Fermi-LAT data
• Gamma Lines without a Continuum: Thermal Models for the Fermi-LAT 130 GeV Gamma Line
• Disentangling Instrumental Features of the 130 GeV Fermi Line
• Probing Charged Matter Through Higgs Diphoton Decay, Gamma Ray Lines, and EDMs
• Top Quark Mediated Dark Matter
• Axion-mediated dark matter and Higgs diphoton signal
• Interplay between Fermi gamma-ray lines and collider searches
• From gamma ray line signals of dark matter to the LHC
• Triangulating an exotic T quark
• Observing Higgs boson production through its decay into gamma-rays: A messenger for Dark Matter candidates

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