Conveners
Dark Matter: DM 1K
- Robert Group (University of Virginia)
- Muti Wulansatiti (Florida State University (US))
- Zhengkang Zhang (Caltech)
Dark Matter: DM 1D
- Ivan Esteban (CCAPP, Ohio State University)
- Hooman Davoudiasl (BNL)
- Suho Kim (Florida State University (US))
Dark Matter: DM 2K
- Robert Group (University of Virginia)
- Muti Wulansatiti (Florida State University (US))
- Zhengkang Zhang (Caltech)
Dark Matter: DM 2D
- Doojin Kim (Texas A&M University)
- Purbita Rahman Prova (Florida State University (US))
- Bhaskar Dutta (Texas A&M University)
Dark Matter: DM 3K
- Bertrand Echenard (California Institute of Technology (US))
- Barmak Shams Es Haghi (University of Utah)
Dark Matter: DM 3D
- Zhengkang Zhang (Caltech)
- Caterina Doglioni (Lund University (SE))
Dark Matter: DM 4D
- Zhengkang Zhang (Caltech)
- LianTao Wang (University of Chicago)
Dark Matter: DM 5D
- Joshua Foster (University of Michigan)
- Hong Ma (Brookhaven National Laboratory (US))
Dark Matter: DM 6D
- Joshua Foster (University of Michigan)
- maria monzani (Stanford University)
The DAMIC experiment at SNOLAB uses thick, fully-depleted, scientific grade charge-coupled devices (CCDs) to search for the interactions between proposed dark matter particles in the galactic halo and the ordinary silicon atoms in the detector. DAMIC CCDs operate with an extremely low instrumental noise and dark current, making them particularly sensitive to ionization signals expected from...
GAMBIT (the Global and Modular Beyond-the-standard-model Inference Tool) is a flexible and extensible framework that can be used to undertake global fits of essentially any BSM theory to relevant experimental data sets. Currently included in code are results from collider searches for new physics, cosmology, neutrino experiments, astrophysical and terrestrial dark matter searches, and...
SuperCDMS deploys cryogenic germanium and silicon detectors which are sensitive in both the athermal phonon and ionization channels to search for dark matter. In order to observe such a small potential signal, all background sources need to be well understood and then mitigated.
Low-background shielding was designed such that the environmental background is negligible compared to the...
Automated tools for the computation of amplitudes and cross sections have become the backbone of phenomenological studies beyond the standard model. We present the latest developments in MadDM, a calculator of dark matter observables based on MadGraph5_aMC@NLO. The new version enables the fully automated computation of loop-induced annihilation processes, relevant for indirect detection of...
The WIMP proposed here yields the observed abundance of dark matter, and is consistent with the current limits from direct detection, indirect detection, and collider experiments, if its mass is $\sim 72$ GeV/$c^2$. It is also consistent with analyses of the gamma rays observed by Fermi-LAT from the Galactic center (and other sources), and of the antiprotons observed by AMS-02, in which the...
The third science run of SuperCDMS HVeV detectors (single-charge sensitive detectors with high Neganov-Trofimov-Luke phonon gain) took place at the NEXUS underground test facility in early 2021, incorporating two important changes to test background hypotheses and enhance sensitivity. First, this was the first HVeV dataset taken underground (300 mwe) and in a shielded environment. Second, the...
We present the theoretical case along with some early measurements with diamond test chips that demonstrate the viability of TES on diamond as a potential platform for direct detection of sub-GeV dark matter.
Diamond targets can be sensitive to both nuclear and electron recoils from dark matter scattering in the MeV and above mass range, as well as to absorption processes of dark matter with...
If dark matter interacts too feebly with ordinary matter, it was not able to thermalize with the bath in the early universe. Such Feebly Interacting Massive Particles (FIMPs) would therefore be produced via the freeze-in mechanism. Testing FIMPs is a challenging task, given the smallness of their couplings. In this talk, I will discuss our recent proposal of a $Z’$ portal where freeze-in can...
Dark, chiral fermions carrying lepton flavor quantum numbers are natural candidates for freeze-in. Small couplings with the Standard Model fermions of the order of lepton Yukawas are ‘automatic’ in the limit of Minimal Flavor Violation. In the absence of total lepton number violating interactions, particles with certain representations under the flavor group remain absolutely stable. For...
ABSTRACT:
HeRALD, the Helium Roton Apparatus for Light Dark Matter, will use a superfluid 4He target to probe the sub-GeV dark matter parameter space. The HeRALD design is sensitive to all signal channels produced by nuclear recoils in superfluid helium: singlet and triplet excimers, as well as phonon-like excitations of the superfluid medium. Excimers are detected via calorimetry with...
Absorption of dark matter (DM) allows direct detection experiments to probe a broad range of DM candidates with masses much smaller than kinematically allowed via scattering. It has been known for some time that for vector and pseudoscalar DM the absorption rate can be related to the target's optical properties, i.e. the conductivity/dielectric. However this is not the case for scalar DM,...
The cold dark matter (CDM) candidate with weakly interacting massive
particles can successfully explain the observed dark matter relic
density in cosmic scale and the large-scale structure of the Universe.
However, a number of observations at the satellite galaxy scale seem
to be inconsistent with CDM simulation.
This is known as the small-scale problem of CDM.
In recent years, it has...
The XENONnT experiment has made great commissioning strides in the last year. Operating at the INFN Gran Sasso National Laboratory in Italy, XENONnT has substantially improved upon its predecessor, XENON1T, which to date is the most sensitive direct-detection dark-matter experiment for spin-independent WIMPs above 6 GeV/c^{2}. As part of its multi-pronged physics program, XENONnT aims to reach...
The Scintillating Bubble Chamber (SBC) is a rapidly developing new technology for 0.7 - 7 GeV nuclear recoil detection. Demonstrations in liquid xenon at the few-gram scale have confirmed that this technique combines the event-by-event energy resolution of a liquid-noble scintillation detector with the world-leading electron-recoil discrimination capability of the bubble chamber, and in fact...
We present models of resonant self-interacting dark matter in a dark sector with QCD, based on analogies to the meson spectra in Standard Model QCD. For dark mesons made of two light quarks, we present a simple model that realizes resonant self-interaction (analogous to the ϕ-K-K system) and thermal freeze-out. We also consider asymmetric dark matter composed of heavy and light dark quarks to...
Dark matter self-interactions have been proposed as a solution to various astrophysical small-scale structure anomalies. We explore the scenario in which dark matter self-interacts through a continuum of low-mass states. This happens if dark matter couples to a strongly-coupled nearly-conformal hidden sector. This type of theory is holographically described by brane-localized dark matter...
The Scintillating Bubble Chamber (SBC) Collaboration is constructing a 10-kg liquid argon bubble chamber with scintillation readout. The goal for this new technology is to achieve a nuclear recoil detection threshold as low as 100 eV with near complete discrimination against electron recoil events. Following initial characterization in a near-surface site at Fermilab, an underground deployment...
I will discuss dark matter production mechanism based on decays of a messenger WIMP-like state into a pair of dark matter particles that are self-interacting via exchange of a light, stable mediator. A natural by-product of this mechanism is a possibility of a late time transition to subdominant dark radiation component which increases the present-day Hubble rate. Simple realization of the...
The detection of low mass dark matter is under development with the advancement of experiment techniques. The superfluid helium-4 detector covers an extensive detection range from DM mass keV to GeV among the setups. I will present a complete theoretical framework for all processes within the superfluid to fill in the missing theory for sub-GeV DM detection. First, we use effective field...
We present two distinct models which rely on 1st order phase transitions in a dark sector. The first is a minimal model for baryogenesis which employs a new dark SU(2) gauge group with two doublet Higgs bosons, two lepton doublets, and two singlets. The singlets act as a neutrino portal that transfers the generated baryon asymmetry to the Standard Model. The model predicts extra relativistic...
Recent theoretical calculations have shown that it is possible to
attempt the direct detection of dark matter in the laboratory through
its gravitational interaction alone. This is particularly relevant
around the well-motivated Planck mass scale (22 micro-g or $10^{19}$ GeV).
The Windchime collaboration is working on arrays of mechanical
accelerometers with quantum-enhanced readout to...
The Axion Dark Matter Experiment (ADMX) is an experiment that searches for axions as dark matter with a resonant cavity in a strong magnetic field. In previous operations, ADMX achieved DFSZ sensitivity between 2.66-3.31 micro eV with yocto Watt level background using a quantum amplifier and dilution refrigerator. The latest operation has searched between 3.3 to 4.2 micro eV between October...
The constituents of dark matter are still unknown, and the viable possibilities span a very large mass range. Specific scenarios for the origin of dark matter sharpen the focus on a narrower range of masses: the natural scenario where dark matter originates from thermal contact with familiar matter in the early Universe requires the DM mass to lie within about an MeV to 100 TeV. Considerable...
I will describe two precision experiments searching for ultralight axion-like dark matter. The SHAFT experiment uses ferromagnetic toroidal magnets, and is sensitive to the electromagnetic coupling in the 12 peV to 12 neV mass range. The CASPEr-e experiment is based on precision magnetic resonance, and is sensitive to the EDM and the gradient couplings in the 162-166 neV mass range. These two...
New theoretical developments have motivated “hidden sector” dark matter with mass below the proton mass. The Light Dark Matter Experiment (LDMX) will use an electron beam to produce dark matter in fixed-target collisions. A low current, high repetition rate (37.2MHz) electron beam extracted from SLAC’s LCLS-II will provide LDMX with sufficient luminosity to explore many dark matter candidates....
Cosmic Axion Spin Precession Experiment (CASPEr) is a laboratory scale experiment searching for ultralight axion-like dark matter, using nuclear magnetic resonance [D. Budker, et al. Phys. Rev. X, 4,021030 and D. Aybas, J. Adam, et al., Phys. Rev. Lett. 126, 141802]. I will describe our work on the next phase of the experiment, with the goal of searching in the kHz – MHz frequency band, using...
New physics beyond the Standard Model (SM) could be responsible for the presence of Dark Matter in the Universe. A hidden, or "dark", sector interacting with SM particles via new force carriers is a natural scenario to explain the features of Dark Matter. In the last decade, growing interest has been dedicated to the search for dark sectors with force carriers in the MeV-GeV mass range. A well...
Cosmological observations indicate that our universe contains dark matter (DM), yet we have no measurements of its microscopic properties. Whereas the gravitational interaction of DM is well understood, its interaction with the Standard Model is not. Direct detection experiments, the current standard, search for nuclear recoil interactions and have low-mass sensitivities down to ~1 GeV. A path...
Detection and understanding of dark matter is one of the major unsolved problems of modern particle physics and cosmology. Several theories of fundamental physics predict bosonic dark matter candidates that can modify Maxwell’s equations resulting in additional photon emission from conducting surfaces. One of these promising dark matter candidates is known as the axion, which could be detected...
The QCD axion represents a well-motivated new physics candidate capable of explaining dark matter and the absence of the neutron electric dipole moment. If realized after the breaking of a Peccei-Quinn symmetry after the end of inflation, the late-time number density of axions is jointly determined by radiation of axions from topological defects known as strings and from the dynamics of the...
The existence of dark matter is ubiquitous in cosmological data, yet numerous particle detectors have been thoroughly looking for it without any success. For strongly interacting dark matter, the bounds from these experiments are actually irrelevant; as dark matter enters the atmosphere, it scatters and slows down, such that it has a much lower velocity than the detector threshold when it...
The existence of dark matter is widely accepted, with a well motivated theo-retical candidate being a class of particles known as WIMPs (weakly interacting massive particles), which appear in the spectra of many extensions to the stan-dard model.
We explore a particular WIMP-like model in which fermionic dark matter weakly couples to the muon/tau sectors of the standard model through a new...
Observations of dark matter structure at the smallest scales can tell us about physical processes taking place in the dark sector at very early times. Here, we point out that the presence of light degrees of freedom coupling to dark matter in the early Universe introduces a localized feature in the halo mass function. This leads to a mass function that is distinct in shape than either warm...
Dwarf galaxies are relatively pristine objects for testing dark matter microphysics due to weak baryonic feedback in them. We use a particular class of dwarfs which are gas-rich to probe DM interactions with ordinary matter. We require the rate of heat exchange between DM and gas to not exceed the low radiative cooling rate of the gas. This gives strong constraints on popular DM models: our...
Indirect detection experiments typically measure the flux of annihilating dark matter (DM) particles propagating freely through galactic halos. We consider a new scenario where celestial bodies "focus" DM annihilation events, increasing the efficiency of halo annihilation. In this setup, DM is first captured by celestial bodies, such as neutron stars or brown dwarfs, and then annihilates...
Macroscopic dark matter is almost unconstrained over a wide ``asteroid-like'' mass range, where it could scatter on baryonic matter with geometric cross section. We show that when such an object travels through a star, it produces shock waves which reach the stellar surface, leading to a distinctive transient optical, UV and X-ray emission. This signature can be searched for on a variety of...
The capture of Dark Matter in Neutron Stars has garnered considerable interest in recent years. This interest is driven by the prospect that the energy deposited by dark matter scattering can heat these objects to infra-red temperatures, which may soon be within reach of observations. In order to obtain reliable results from these searches, proper incorporation of the physics of Neutron stars...
In recent years, the usefulness of astrophysical objects as Dark Matter (DM) probes has become more and more evident, especially in view of null results from direct detection and particle production experiments. The potentially observable signatures of DM gravitationally trapped inside a star, or another compact astrophysical object, have been used to forecast stringent constraints on the...
We study the simplest viable dark matter model with an additional neutral real singlet scalar, including a vectorlike singlet and doublet fermions. We find a considerable enhancement in the allowed region of the scalar dark matter parameter spaces in the presence of these fermions. This model could also accommodate tiny neutrino masses and mixing at one loop-level through the radiative seesaw...
A search is presented for new particles in proton-proton collisions at $\sqrt{s}$ = 13 TeV at the LHC, using events with energetic jets and large missing transverse momentum. The analysis is based on a data sample corresponding to an integrated luminosity of 101 $\mathrm{fb}^{-1}$, collected in 2017–2018 with the CMS detector. Separate categories are defined for events with narrow jets from...
The visible content of the Universe is made up of baryons and almost without of anti-baryons, so it requires a baryogenesis mechanism to generate the baryon asymmetry and it is widely believed that successful baryogenesis requires extending the Standard Model. There are strong evidence of invisible contents, Dark Matter (DM) in the universe in astrophysical observations, such as rotational...
Pair production of dark photons is predicted from models of supersymmetry. When both dark photons decay into muon pairs, a trigger selection with three muons can be highly efficient for GeV-scale dark photons. We report the results of a simulation study of the CMS detector for p-p collisions at 14 GeV with average pile-up (interactions per bunch crossing) of 200. In this study, the dark...
We present a search for dark matter production in events with missing transverse momentum and a Higgs boson decaying to a photon pair using 139 fb$^{-1}$ of $pp$ collisions recorded by the ATLAS experiment at a center-of-mass energy of 13 TeV. The search considers three simplified dark matter models which include either vector or pseudo-scalar mediators and predict final states with a pair of...
Some new physics extensions of the Standard Model predict that the 125 GeV Higgs boson can be a portal to invisible dark matter candidates through its decay. Direct searches for Higgs boson decay to invisible particles are a convenient way to explore this scenario. I present the results of a search for invisible decays of the Higgs boson produced through the vector boson fusion channel (+low...
We investigate the effects of producing dark matter by Hawking evaporation of primordial black holes (PBHs) in scenarios that may have a second well-motivated dark matter production mechanism, such as freeze-out, freeze-in, or gravitational production. We show that the interplay between PBHs and the alternative sources of dark matter can give rise to model-independent modifications to the...
We investigate Hawking evaporation of a population of primordial black holes (PBHs) as a novel mechanism to populate a dark sector which consists of self-interacting scalar dark matter with pure gravitational coupling to the visible sector. We demonstrate that depending on initial abundance of PBHs and the dark matter mass, the dark sector can reach chemical equilibrium with a temperature...
Primordial black holes (PBHs), possibly formed via gravitational collapse of large density perturbations in the very early universe, are one of the earliest proposed and viable dark matter (DM) candidates. Recent studies indicate that PBHs can make up a large or even entire fraction of the present day DM density for a wide range of masses. Ultralight
PBHs in the mass range of 10^{15} -...
The extended excess towards the Galactic Center (GC) in gamma rays inferred from Fermi-LAT observations has been interpreted as being due to dark matter (DM) annihilation. In a recent paper my collaborators and I performed a new likelihood analyses of the GC and showed that when including templates for the stellar galactic and nuclear bulges, the GC shows no significant detection of a DM...
The Cherenkov Telescope Array (CTA) is the next-generation ground-based observatory for very-high-energy (VHE, E>100 GeV) gamma-rays. It will consist of more than 100 imaging atmospheric Cherenkov telescopes (IACTs) divided between two arrays in the Northern and the Southern hemispheres. Featuring telescopes with different sizes, it will provide coverage of the whole sky over a wide energy...
The discovery of diffuse sub-PeV gamma-rays by the Tibet ASγ collaboration promises to revolutionize our understanding of the high-energy astrophysical universe. It has been shown that this data broadly agrees with prior theoretical expectations. In this talk, We will discuss the impact of this discovery on a well-motivated new physics scenario: PeV-scale decaying dark matter (DM). Considering...
