Session G09: Mini-symposium: Innovative Dark Matter Detection II

LAMPOST: First Constraints on Dark Photon Dark Matter with an Optical Haloscope

We demonstrate a proof-of-concept search for dark photon dark matter in the 0.7-0.8 eV mass range via coherent absorption in a multi-layer dielectric haloscope. This new experimental architecture optically focuses the signal from a compact target to a sub-mm-scale SNSPD, breaking conventional trade-offs in DM experiments requiring macroscopic panels of expensive and noisy detectors. Our SNSPD achieved a dark count rate of 6x10⁻⁶ counts/s, the lowest reported among all types of superconducting sensors, while still achieving close to 20% detection efficiency at 1700 nm wavelength. With less than one week of run time, our prototype constrains new dark photon DM parameter space in this mass range. After a rigorous analysis of the prototype’s strengths and shortcomings, we outline crucial improvements that could enable rapid searches over the meV to 10 eV mass range using this technology in the near future.   

A new high voltage cable feedthrough concept for future dark matter and neutrino experiments

Physics experiments featuring liquid noble gas time projection chambers are becoming larger in scale.

Consequently, their high voltage (HV) requirements have increased as well, making conventional design HV feedthrough (FT) impracticable.

In this talk, a new concept for a HV cable FT usable in cryogenic environment is presented.

It features a co-extruded multi-layered coaxial cable fabricated with a single material and relies on the ability to develop a plastic material with tunable resistivity.   

Interactions of dark matter portals

 

Dark matter(DM) origin cover a vast range of materials, from weakly interacting massive particles (WIMPs) to axions, dark photons, new neutrino species, primordial black holes, superfluids and more. In freeze-out mechanism where DM decouples from the visible sector heat bath as the expansion rate of the universe wins over the interaction rate of DM and heat bath particles. Consequently, the commoving number density of DM particles freezes to a constant value. In freeze-in mechanism which is based on the assumption that the DM phase space is initially unpopulated, but subsequently produced from the visible sector by decays or annihilations. Also, the dark sector can have rich dynamics as combinations of the previous two mechanisms. For example if dark matter has self- interactions, it can, after initially populated by freeze-in from the visible sector, constitute a heat bath within itself but decoupled from the visible sector. The Higgs Portal, The Vector Porta, Axion Portal, Neutrino Portal, interactions with SM as well as, Strongly Coupled Composite Dark Matter, Dark Pions, Dark Quarkonia and Dark Baryons, Dark Glueballs are possible..

 

Due to the lack of any compelling evidence for the existence of WIMP dark matter despite many searches are probing into the plausible WIMP parameter space, many theoretical developments are now going beyond the minimal WIMP model or alter its basic assumptions. If one considers the possibility that dark matter is produced at the LHC, and that its interaction cross section with normal matter is so high that the particles are no longer WIMPs, but become SIMPs or strongly interacting massive particles. With an interaction cross section as large as the hadronic one, these SIMPs manifest themselves as jets in the calorimeter, but with no tracks in the tracking detector from charged hadrons, in sharp contrast to typical quantum chromodynamics (QCD) jets.

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The NEWS-G light dark matter experiment: Results with a hydrogen-rich target

The NEWS-G direct detection experiment employs Spherical Proportional Counters (SPCs) with light atom gas mixtures to search for low-mass Dark Matter (DM). NEWS-G has already set competitive constraints on spin-independent interactions at the Laboratoire Souterrain de Modane (LSM), and is commissioning a new 140 cm diameter SPC at SNOLAB in Sudbury, Canada, with improved shielding, sensor technology, and radio-pure construction. Earlier in development, this SPC was operated at the LSM with a 135 mbar methane target gas for a limited physics campaign. This hydrogen rich target allows for sensitivity to DM particle masses of approximately 100 MeV/c². Robust calibrations of the detector response to single-electron ionizations are necessary to exploit this potential, which is done primarily with a UV laser and ³⁷Ar. These and other preliminary results will be presented, as well as an overview of the experimental setup.   

Systematic investigation of minimal Scotogenic models

We carry out a systematic investigation for minimal Scotogenic models based on a dark U(1)_D gauge symmetry, in which the neutrino masses are induced at the one-loop level and include a chiral dark matter (DM) candidate. Moreover, we assume this U(1)_D gauge symmetry is broken by only one Higgs singlet scalar that also generates masses to all dark fermions. The stability of the DM candidate is ensured by a residual symmetry of U(1)_D gauge symmetry. Furthermore, we also explore the associated DM phenomenology of one of the minimal models.   

The progress of the ALETHEIA project in 2021

The ALETHEIA (A Liquid hElium Time projection cHambEr In dArk matter) aims to hunt for low-mass WIMPs with a liquid helium TPC. The temperature of liquid helium filling in the TPC is at $\sim$ 4 K. Cooling helium to 4 K is easier than doing it to superfluid helium ( below 2.17 K). There are lots of technical challenges ahead since no single LHe TPC has ever been demonstrated for DM hunting yet, though LXe (Liquid Xenon) and LAr (Liquid Argon) TPCs achieved great success in DM (Dark Matter) searches. The project was successfully reviewed by a panel composed of leading physicists in the community of DM and LHe in Oct 2019. Since then, we have built a liquid helium prototype detector successfully. We will mainly share experiences of making such a detector and present preliminary results on testing it.   

A new experiment to search for hidden sector particles in the 3-60 MeV range using the PRad experimental setup

A new experiment will search the 3-60 MeV mass region for hidden sector particles produced through a Bremsstrahlung-like process. This experiment is unique in that it will detect all final-state particles, will be sensitive to both charged and neutral decay products, and will have both high-resolution energy and position information for charged decay products. Two beam energies will be used to suppress “false bumps” from kinematical reflections from known physics processes. Our search will be able to resolve the hypothetical X17 anomaly seen in two measurements at the ATOMKI accelerator. This experiment will use the PRad experimental setup in Hall B at Jefferson Lab. The setup consists of a 1µm Tantalum target that is 7.5m upstream of two GEM planes separated by 0.1m and the HyCal calorimeter. New GEM planes will allow for tracking of the recoil electron and charged decay products to reduce beam-related backgrounds. This experiment will have a coupling constant, ε², sensitivity from 7.2×10^-8 to 5.9×10^-9. The proposal was brought to JLab PAC49 and is now a conditionally-approved experiment.