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A<sc>bstract</sc> We study a class of models in which the particle that constitutes dark matter arises as a composite state of a strongly coupled hidden sector. The hidden sector interacts with the Standard Model through the neutrino portal, allowing the relic abundance of dark matter to be set by annihilation into final states containing neutrinos. The coupling to the hidden sector also leads to the generation of neutrino masses through the inverse seesaw mechanism, with composite hidden sector states playing the role of the singlet neutrinos. We focus on the scenario in which the hidden sector is conformal in the ultraviolet, and the compositeness scale lies at or below the weak scale. We construct a holographic realization of this framework based on the Randall-Sundrum setup and explore the implications for experiments. We determine the current constraints on this scenario from direct and indirect detection, lepton flavor violation and collider experiments and explore the reach of future searches. We show that in the near future, direct detection experiments and searches forμ→econversion will be able to probe new parameter space. At colliders, dark matter can be produced in association with composite singlet neutrinos via Drell Yan processes or in weak decays of hadrons. We show that current searches at the Large Hadron Collider have only limited sensitivity to this new production channel and we comment on how the reconstruction of the singlet neutrinos can potentially expand the reach.
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The Search for Electroweakinos
In this review, we consider a general theoretical framework for fermionic color-singlet states—including a singlet, a doublet, and a triplet under the Standard Model SU(2) L gauge symmetry, corresponding to the bino, higgsino, and wino in supersymmetric theories—generically dubbed electroweakinos for their mass eigenstates. Depending on the relations among these states’ three mass parameters and their mixing after the electroweak symmetry breaking, this sector leads to a rich phenomenology that may be accessible in current and near-future experiments. We discuss the decay patterns of electroweakinos and their observable signatures at colliders, review the existing bounds on the model parameters, and summarize the current statuses of the comprehensive searches by the ATLAS and CMS Collaborations at the Large Hadron Collider. We also comment on the prospects for future colliders. An important feature of the theory is that the lightest neutral electroweakino can be identified as a weakly interacting massive particle cold dark matter candidate. We take into account the existing bounds on the parameters from the dark matter direct detection experiments and discuss the complementarity of the electroweakino searches at colliders.
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- Award ID(s):
- 1915147
- PAR ID:
- 10278848
- Date Published:
- Journal Name:
- Annual Review of Nuclear and Particle Science
- Volume:
- 70
- Issue:
- 1
- ISSN:
- 0163-8998
- Page Range / eLocation ID:
- 425 to 454
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1146/annurev-nucl-031020-121031
