Reducing cosmological small scale structure via a large dark matter-neutrino interaction: constraints and consequences

Abstract

Cold dark matter explains a wide range of data on cosmological scales. However, there has been a steady accumulation of evidence for discrepancies between simulations and observations at scales smaller than galaxy clusters. Solutions to these small scale structure problems may indicate that simulations need to improve how they include feedback from baryonic matter, or may imply that dark matter properties differ from the standard cold, noninteracting scenario. One promising way to affect structure formation on small scales is a relatively strong coupling of dark matter to neutrinos. We construct an experimentally viable, simple, renormalizable, model with new interactions between neutrinos and dark matter. We show that addressing the small scale structure problems requires dark matter with a mass that is tens of MeV, and a present-day density determined by an initial particle-antiparticle asymmetry in the dark sector. Generating a sufficiently large dark matter-neutrino coupling requires a new heavy neutrino with a mass around 100 MeV. The heavy neutrino is mostly sterile but has a substantial τ neutrino component, while the three nearly massless neutrinos are partly sterile. We provide the first discussion of how such dark matter-neutrino interactions affect neutrino (especially τ neutrino) phenomenology. This model can be tested by future astrophysical, particle physics, and neutrino oscillation data. A feature in the neutrino energy spectrum and flavor content from a future nearby supernova would provide strong evidence of neutrino-dark matter interactions. Promising signatures include anomalous matter effects in neutrino oscillations due to nonstandard interactions and a component of the τ neutrino with mass around 100 MeV.

Monochromatic dark neutrinos and boosted dark matter in noble liquid direct detection

“…Dark neutrino fluxes arise naturally in neutrino portal dark matter models [20][21][22]. When interpreting our constraints in terms of this setup, parametric regions that could potentially explain the "missing satellites" problem of structure formation can be probed extensively.…”

Dark matter, neutrino mass, cutoff for cosmic-ray neutrino, and the Higgs boson invisible decay from a neutrino portal interaction

“…10. There are several constraints for N , because it behaves as a right-handed neutrino with Yukawa coupling y and the mass M[101,102]. If we adopt the constraint in[102] for a heavy right-handed neutrino, which dominantly mixes with τ neutrino,…”

Highly-boosted dark matter and cutoff for cosmic-ray neutrinos through neutrino portal

“…5 ψ, if is extended into a Dirac fermion, can be asymmetric dark matter [5]. Interestingly, the parameter region for addressing small-scale structure issues also has y τ U τ = O(0.1) and m DM = O(10 − 100) MeV [6], which may be coincident with the parameter region suppressing cosmic-ray neutrinos and highly boosted dark matter. The clarification of the coincidence will be our future study.…”

“…When the neutrinos portal is through ν µ or ν e the experiment constraints becomes severer [6]. The measurement on meson decays sets stringent constraints and almost excludes all the viable region supressing the cosmic-ray neutrino with M Ri m K ∼ 500 MeV.…”

“…In particular, the neutrinos can interact with a dark sector, whose participants can carry some hidden charge, so that the lightest particle is stable to explain the dark matter i.e. there could be neutrino portal interaction relevant to dark matter [5,6]. It was pointed out that a cutoff for the cosmic-ray neutrino can be set through its scattering with cosmic background neutrinos (CνB) into the dark sector particles through the neutrino-portal interaction by using an effective theory approach [7].…”