200 research outputs found
Constraints on Dark Matter Protohalos in Effective Theories and Neutrinophilic Dark Matter
The mass of primordial dark matter (DM) protohalos remains unknown. However,
the missing satellites problem may be an indication that they are quite large.
In this paper, we use effective field theory to map constraints on dark
matter-SM interactions into limits on the mass of DM protohalos. Given that
leptons remain in the thermal bath until late times, we focus on their
interactions with DM. To illustrate the method, we use the null results of LEP
missing energy searches along with Fermi-LAT searches for DM annihilation in
nearby dwarf galaxies, to derive limits on the protohalo mass, , with the range depending on the DM mass and the
operator. Thus, if DM is to remain thermally coupled until late times and
account for the missing satellites, charged lepton interactions are
insufficient. This motivates neutrinophilic DM, which can have protohalo masses
orders of magnitude larger, with constraints arising from Planck, IceCube and
unpublished Super-K data. We show that effective neutrinophilic models offer a
solution to the missing satellites problem for sub-GeV DM masses with larger
than WIMP-sized annihilation cross sections.Comment: 8 pages, 4 figure
Asymptotically Safe Dark Matter
We introduce a new paradigm for dark matter (DM) interactions in which the
interaction strength is asymptotically safe. In models of this type, the
coupling strength is small at low energies but increases at higher energies,
and asymptotically approaches a finite constant value. The resulting
phenomenology of this "asymptotically safe DM" is quite distinct. One
interesting effect of this is to partially offset the low-energy constraints
from direct detection experiments without affecting thermal freeze-out
processes which occur at higher energies. High-energy collider and indirect
annihilation searches are the primary ways to constrain or discover
asymptotically safe dark matter.Comment: 5 pages, 2 multi-panel figures, PRD versio
Mapping The Neutrino Floor For Dark Matter-Electron Direct Detection Experiments
We study the discovery reach of future Dark Matter (DM) Direct Detection
experiments using DM-electron scattering in the presence of the solar neutrino
background. At these low energies traditional methods for nuclear and
electronic recoil discrimination fail, implying that the neutrino-{\it nucleus}
scattering background can be sizable. We calculate discovery limits based on
ionization values of signal and background, and quantify the dependence on the
ionization model. Moreover, we explore how the dependence of the DM cross
section discovery limits vary with exposure, electronic/nuclear recoil
discrimination, DM form factors, and DM astrophysical uncertainties.Comment: 10 pages, 9 figure
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