Using Secondary Tau Neutrinos to Probe Heavy Dark Matter Decays in Earth

Abstract

Dark matter particles can be gravitationally trapped by celestial bodies, motivating searches for localized annihilation or decay. If neutrinos are among the decay products, then IceCube and other neutrino observatories could detect them. We investigate this scenario for dark matter particles above $m_{\chi }\gtrsim$ PeV producing tau neutrino signals, using updated modeling of dark matter capture and thermalization. At these energies, tau neutrino regeneration is an important effect during propagation through Earth, allowing detection at distances far longer than one interaction length. We show how large energy loss of tau leptons above $\sim$ PeV drives a wide range of initial energies to the same final energy spectrum of "secondary" tau neutrinos at the detector, and we provide an analytic approximation to the numerical results. This effect enables an experiment to constrain decays that occur at very high energies, and we examine the reach of the IceCube high-energy starting event (HESE) sample in the parameter space of trapped dark matter annihilations and decays above PeV. We find that the parameter space probed by IceCube searches would require dark matter cross sections in tension with existing direct-detection bounds.

Updated to include projected IceCube-Gen2 sensitivity, various minor revisions for clarity, some references added

References in corpus (15)

• IceCube-Gen2: The Window to the Extreme Universe
• The IceCube high-energy starting event sample: Description and flux characterization with 7.5 years of data
• Physics Reach of High-Energy and High-Statistics IceCube Atmospheric Neutrino Data
• Constraining Very Heavy Dark Matter Using Diffuse Backgrounds of Neutrinos and Cascaded Gamma Rays
• A Comprehensive Approach to Tau-Lepton Production by High-Energy Tau Neutrinos Propagating Through Earth
• Evaporation of dark matter from celestial bodies
• Dark Matter, Destroyer of Worlds: Neutrino, Thermal, and Existential Signatures from Black Holes in the Sun and Earth
• Direct Detection Limits on Heavy Dark Matter
• A Dark Matter Interpretation of the ANITA Anomalous Events
• Observing EeV neutrinos through the Earth: GZK and the anomalous ANITA events
• Can the ANITA anomalous events be due to new physics?
• Erratum: A Comprehensive Approach to Tau-Lepton Production by High-Energy Tau Neutrinos Propagating Through Earth [Phys. Rev. D 97, 023021 (2018), arXiv:1707.00334]
• Oscillations of sterile neutrinos from dark matter decay eliminates the IceCube-Fermi tension
• Contribution of Secondary Neutrinos from Line-of-sight Cosmic Ray Interactions to the IceCube Diffuse Astrophysical Flux
• Indirect dark matter searches at ultrahigh energy neutrino detectors