A bstract We study a renormalizable model of Dirac fermion dark matter (DM) that communicates with the Standard Model (SM) through a pair of mediators — one scalar, one fermion — in the representation ( 6 , 1 , $$ \frac{4}{3} $$ 4 3 ) of the SM gauge group SU(3) c × SU(2) L × U(1) Y . While such assignments preclude direct coupling of the dark matter to the Standard Model at tree level, we examine the many effective operators generated at one-loop order when the mediators are heavy, and find that they are often phenomenologically relevant. We reinterpret dijet and pair-produced resonance and jets + $$ {E}_{\mathrm{T}}^{\mathrm{miss}} $$ E T miss searches at the Large Hadron Collider (LHC) in order to constrain the mediator sector, and we examine an array of DM constraints ranging from the observed relic density Ω χ $$ {h}_{\mathrm{Planck}}^2 $$ h Planck 2 to indirect and direct searches for dark matter. Tree-level annihilation, available for DM masses starting at the TeV scale, is required in order to produce Ω χ $$ {h}_{\mathrm{Planck}}^2 $$ h Planck 2 through freeze-out, but loops — led by the dimension-five DM magnetic dipole moment — are nonetheless able to produce signals large enough to be constrained, particularly by the XENON1T experiment. In some benchmarks, we find a fair amount of parameter space left open by experiment and compatible with freeze-out. In other scenarios, however, the open space is quite small, suggesting a need for further model-building and/or non-standard cosmologies.
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Is a Miracle-less WIMP Ruled out?
We examine a real electroweak triplet scalar field as dark matter,abandoning the requirement that its relic abundance is determinedthrough freeze out in a standard cosmological history (a situation whichwe refer to as `miracle-less WIMP’). We extract the bounds on such aparticle from collider searches, searches for direct scattering withterrestrial targets, and searches for the indirect products ofannihilation. Each type of search provides complementary information,and each is most effective in a different region of parameter space. LHCsearches tend to be highly dependent on the mass of the SU(2) chargedpartner state, and are effective for very large or very tiny masssplitting between it and the neutral dark matter component. Directsearches are very effective at bounding the Higgs portal coupling, butineffective once it falls below \lambda_{\text{eff}} \lesssim 10^{-3} λ eff ≲ 10 − 3 .Indirect searches suffer from large astrophysical uncertainties due tothe backgrounds and J J -factors,but do provide key information for \sim ∼ 100 GeV to TeV masses. Synthesizing the allowed parameter space, thisexample of WIMP dark matter remains viable, but only in miracle-lessregimes.
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- Award ID(s):
- 1915005
- NSF-PAR ID:
- 10346109
- Date Published:
- Journal Name:
- SciPost Physics
- Volume:
- 11
- Issue:
- 2
- ISSN:
- 2542-4653
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
-
Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.21468/SciPostPhys.11.2.019
