Conveners
Dark Matter: I - BioSci 1101
- Ilias Cholis (Oakland University)
Dark Matter: II - BioSci 1101
- David Curtin (University of Toronto)
Dark Matter: IV - Chernoff Auditorium
- Daniel Gilman
Dark Matter: III - Stirling Auditorium
- Seodong Shin (Jeonbuk National University)
Dark Matter: V - Stirling Auditorium
- Christopher Cappiello
Dark Matter: VI - Chernoff Auditorium
- Aion Viana (IFSC-USP)
Dark Matter: VII - BioSci 1101
- Erez Etzion (Tel Aviv University (IL))
Dark Matter: VIII - BioSci 1102
- Tomas Gonzalo (Karlsruhe Institute for Technology (KIT))
Dark Matter: IX - BioSci 1101
- Marco Chianese
Dark Matter: X - BioSci 1102
- Elena Pinetti (Fermilab)
Dark Matter: XII - Stirling Auditorium
- Philip Von Doetinchem (University of Hawaii at Manoa)
Dark Matter: XI - Chernoff Auditorium
- Marco Taoso
Dark Matter: XIV - Stirling Auditorium
- Nassim Bozorgnia (York University, University of Alberta)
Dark Matter: XIII - Chernoff Auditorium
- Sara Rebecca Gozzini
Complex Dark Sectors are theories of hidden particles and forces that could constitute all or part of dark matter but have non-minimal interactions between them, such as dark analogues of electromagnetism of the strong force. These scenarios are predicted by many highly motivated extensions of the Standard Model that solve fundamental mysteries like the hierarchy problem, but are notoriously...
An intriguing possibility for dark matter is that it formed bound states in the early Universe, in a scenario called 'composite' dark matter, much like the Standard Model fundamental particles formed nucleons, nuclei and atoms. One of the simplest composite dark matter models consists of dark fermions bound together by a real scalar field. Composite states that are massive enough source scalar...
The addition of spatial dimensions compactified to submillimeter scales serves as an elegant solution to the hierarchy problem. As a consequence of such large extra dimensions, is the possibility of producing primordial black holes (PBHs) from high-energy collisions in the early universe, leading to a novel source of dark matter. While four-dimensional PBHs have been extensively studied, they...
Magnetic monopoles and Q-balls are examples of topological and nontopological solitons, respectively. A new soliton state with both topological and nontopological charges is shown to also exist, given a monopole sector with a portal coupling to an additional scalar field S with a global U(1) symmetry. This new state, the Q-monopole-ball, is more stable than an isolated Q-ball made of only S...
The Galactic Centre (GC) region is a promising target for dark matter (DM) search due to the size of its halo and proximity. We report on the search for DM spectral gamma-ray lines in the GC region up to gamma-ray energies of 100 TeV with the MAGIC telescopes, located on the island of La Palma (Spain). We present the results obtained with more than 200 hours of large-zenith angle observations...
A bright and statistically significant flux of GeV-scale gamma rays has been detected from the region surrounding the Galactic Center. While the spectrum, angular distribution, and intensity of this signal is consistent with the predictions of annihilating dark matter matter particles, it has also been suggested that these gamma rays could potentially be produced by a large population of...
We present a new reconstruction of the distribution of atomic hydrogen in the inner Galaxy that is based on explicit radiation-transport modelling of line and continuum emission and a gas-flow model in the barred Galaxy that provides distance resolution for lines of sight toward the Galactic Center. The main benefits of the new gas model are, a), the ability to reproduce the negative line...
The Galactic Center Excess (GCE) remains one of the most intriguing discoveries from the Fermi Large Area Telescope (LAT) observations. I will revisit the characteristics of the GCE by using a new set of high-resolution galactic diffuse gamma-ray emission templates. This diffuse emission, which accounts for the bulk of the observed gamma rays, is ultimately due to cosmic-ray interactions with...
Using the data from the Large Area Telescope (LAT), the Fermi-LAT collaboration continuously updates their catalogs, which now contain a few thousands of detected gamma-ray sources. Among them, around one third are of not yet identified origin, and they could contain signals from established source types or, most intriguing, new source types such as dark matter subhalos producing gamma-rays...
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 instrument noise and dark current, making them particularly sensitive to ionization signals expected from...
Cosmological and astrophysical observations suggest that 85% of the total matter of the Universe is made of Dark Matter (DM). However, its nature remains one of the most challenging and fundamental open questions of particle physics. Assuming particle DM, this exotic form of matter cannot consist of Standard Model (SM) particles. Many models have been developed to attempt unraveling the nature...
We develop a novel formalism to describe the scattering of dark matter (DM) particles by electrons bound in detector materials such as silicon, germanium and graphene for a general form of the underlying DM-electron interaction. By applying non-relativistic effective field theory methods, we find that the DM and material physics factorise into a handful of DM and material "response functions"....
Dark matter at the keV scale has become an active topic in the last decade. The NuSTAR x-ray observatory, with its energy bandpass 3--150 keV and wide-angle aperture for unfocused x-rays, is an ideal platform to search for decaying keV-scale dark matter, e.g. sterile neutrinos. Previous NuSTAR analyses constrained much of the sterile-neutrino parameter space for masses ~10--40 keV, improving...
Direct detection experiments set strong constraints on dark matter-nucleus scattering, but are typically limited to probing dark matter velocities of order 10^-3 c. If there exists a sub-population of dark matter with much larger velocity, considering this population could make direct detection experiments sensitive to smaller dark matter mass, while also improving their sensitivity to cross...
We propose a novel mechanism of boosting dark matter by cosmic-ray neutrinos. The new mechanism is so significant that the arriving flux of cosmic-ray neutrino boosted dark matter (νBDM) lighter than O(1) MeV on Earth substantially larger than the one of the cosmic-ray electron boosted dark matter. Therefore, νBDM can dominantly contribute in direct detection experiments. We derive...
The true nature of the largest matter density component of the Universe, the so-called dark matter, is one of the most elusive problems of Physics. One primary candidate to explain dark matter are Weakly Interacting Massive Particles (WIMPs), as they provide the right relic density with a cross-section at the electroweak scale, however, up-to-date no WIMP signals were observed until now....
Dark matter halos and subhalos less massive than 10^9 solar masses hold the key to understanding the nature of dark matter, including its formation mechanism, particle mass, and possible interactions. In particular, self-interacting dark matter (SIDM) prescribes a dynamic evolution of halo density profiles that distinguishes it from cold dark matter. This process begins with core formation,...
Primordial black holes (PBHs) are a potential dark matter candidate whose masses can span over many orders of magnitude. If they have masses in the 10^15 − 10^17 g range, they can emit sizeable fluxes of MeV neutrinos through evaporation via Hawking radiation. We explore the possibility of detecting light (non-)rotating PBHs with future neutrino experiments DUNE and THEIA. We will show that...
The direct detection of sub-GeV dark matter interacting with nucleons is hampered by the low recoil energies induced by scatterings in the detectors. This experimental difficulty is avoided in the scenario of boosted dark matter where a component of dark matter particles is endowed with large kinetic energies. In this talk, I will show that the current evaporation of primordial black holes...
Strong gravitational lensing provides a promising way to look for clues to the elusive particle nature of dark matter. Indeed, subtle perturbations to lensed images can reveal the dark-matter distribution on sub-galactic scales. In addition to the subhalos of the main lens, a significant contribution to these perturbations comes from dark matter halos along the line-of-sight between the...
We emphasize the distinctive cosmological dynamics in multi-component dark-matter scenarios and its impact in probing a sub-dominant component of dark matter.
The dynamics originates from the conversion among different dark-matter components.
We find that the temperature of the self-interacting sub-component dark matter is significantly enhanced by the dark-matter annihilation into the...
The fundamental nature of dark matter so far eludes direct detection experiments, but it has left its imprint in the large-scale structure (LSS) of the Universe. Extracting this information requires accurate modelling of structure formation and careful handling of astrophysical uncertainties. I will present new bounds using the LSS on two compelling dark matter scenarios that are otherwise...
We present converged ab initio calculations [1] of structure factors for elastic spin-dependent WIMP scattering off all nuclei used in dark matter direct-detection searches: 19F, 23Na, 27Al, 29Si, 73Ge, 127I, 129Xe, and 131Xe. From a set of established two- and three-nucleon interactions derived within chiral effective field theory, we construct consistent WIMP-nucleon currents at the one-body...
The isothermal Jeans model is a semi-analytical approach to modelling galaxies and galaxy clusters with self-interacting dark matter (SIDM) that has been shown to work remarkably well. Recent studies have found great success testing Jeans model predictions for SIDM halos against both observations and simulations while assuming spherical symmetry. In the presence of baryons SIDM halos are known...
Strongly-lensed galaxies are a unique laboratory for probing dark matter substructure and testing the fundamental assumptions of the ΛCDM paradigm. However, the statistical difficulties with analyzing such observations are formidable, requiring disentangling the source galaxy’s light from the lens’ mass distribution and marginalizing over different substructure configurations. In this talk I...
Dark matter in cosmic structures is expected to produce signals that originate from its particle-like nature, among which the electromagnetic emission represents a relevant opportunity. However, this emission is very faint and contributes only to the unresolved background radiation. This background emission is isotropic at first order, but exhibits a degree of anisotropy since it originates...
The NEWS-G direct dark matter search experiment uses spherical proportional counters (SPC) with light noble gasses to explore low WIMP masses. The current iteration of the experiment consists of a large 140 cm diameter SPC installed at SNOLAB with a new sensor design, and lots of improvements in detector performance and data quality. Before its installation at SNOLAB, the detector was operated...
The latest results from DEAP-3600 will be presented, including the best constraints on TeV-scale mass dark matter scattering in argon, and world-leading constraints on Planck-scale mass dark matter. DEAP-3600 is located at SNOLAB, 2 km underground in Sudbury, Ontario. This spherical detector consists of 3.3 tonnes of liquid argon in a large ultralow-background acrylic cryostat instrumented...
Parton showers are part and parcel of particle phenomenology, but what in the case of a confining dark sector with no light quarks below the confinement scale? Then the only available hadronic states are ‘glueballs’, composite gluon states. To date, there have been very few quantitative studies of dark shower signatures with glueball final states, despite the fact they commonly appear in...
The Technical Design of the DarkSide-20k experiment has been finalised and the detector construction in the Gran Sasso National Laboratory in Italy starts this year. The experiment is designed to observe WIPMs scattering from argon atoms in 20 tonnes of the liquid argon target. Scintillation light generated during the interaction is detected by planes of Silicon photomultipliers (SiPMs). The...
Cosmological and astrophysical probes suggest that dark matter (DM) would make up for 85\% of the total matter content of the Universe. However, the determination of its nature remains one of the greatest challenges of fundamental physics. Assuming the $\Lambda$CDM model, Weakly Interacting Massive Particles (WIMPs) would annihilate into Standard Model particles, such as $\gamma$ rays, which...
Darkside-20k will exploit the physical and chemical properties of liquid argon housed within a large dual-phase time project chamber (TPC) in its direct search for dark matter. The TPC will utilize a compact, integrated design with many novel features to enable the 20t fiducial volume of underground argon. Underground argon (UAr) is sourced from underground CO2 wells and depleted in the...
Warm dark matter (WDM) could explain some small-scale structure observations that have challenged the cold dark matter (CDM) model, as warm particles suppress structure formation due to free streaming effects. Observing small-scale structure thus provides a valuable way to distinguish between CDM and WDM. In this talk, I will present a semi-analytical model of the dark matter substructure...
We are going to present the CYGNO/INITIUM project, an experiment that emerges as a new approach for directional Dark Matter searches using a gaseous TPC with the purpose of detecting low mass (0.5-50 GeV) WIMPS and performing solar neutrino spectroscopy. This project distinguishes itself by the use of He:CF$_4$, a low-density gas mixture sensitive to both spin dependent and independent...
The detection of very high-energy neutrinos by the IceCube experiment supports the existence of a comparable gamma-ray counterpart from the same cosmic accelerators. Under the likely assumption that the sources of these particles are of extra-galactic origin, even for transparent sources the photon flux would be significantly absorbed during its propagation over cosmic distances. However, in...
The PICO collaboration searches for WIMPs using large superheated liquid detectors, or bubble chambers. Recent results from the complete exposure of the PICO-60 C$_3$F$_8$ detector at SNOLAB set the world’s most stringent limits on WIMP-proton spin-dependent interactions. I will present the current status of the construction and physics potential of the next generation, tonne-scale experiment...
The SENSEI Experiment leads the direct-detection searches for sub-GeV dark matter (DM) using the novel Skipper-CCD sensors. The Skipper-CCDs can provide repetitive non-destructive readouts of a single pixel’s charge reducing the noise to a negligible level and reaching a single electron distinction.
Already with the small-scale prototype runs, SENSEI achieved the lowest rates in silicon...
Axion-like particles (ALPs) are a well-motivated candidate for constituting a significant fraction of dark matter. They are produced in high-energy environments, such as core-collapse supernovae (CCSNe), and could undergo conversion into gamma-rays in the presence of an external magnetic field, with a characteristic spectrum peaking in the 30--100-MeV energy range. CCSNe are often invoked as...
Axion-like particles (ALPs) decaying before the time of recombination can have
strong implications in a range of cosmological and astrophysical observations. In this
talk I present a global analysis of a model of decaying ALP, focusing specifically on their
coupling to photons. Exploiting the multidisciplinary nature of the GAMBIT frame-
work, we combine state-of-the-art calculations of...
The SABRE (Sodium iodide with Active Background REjection) experiment aims to detect an annual rate modulation from dark matter interactions in ultra-high purity NaI(Tl) crystals in order to provide a model independent test of the signal observed by DAMA/LIBRA. It is made up of two separate detectors; SABRE South located at the Stawell Underground Physics Laboratory (SUPL), in regional...
Potassium-40 (40K) is a naturally-occurring radioactive isotope. It is a background in rare-event searches, plays a role in geochronology, and has a nuclear structure of interest to theorists. This radionuclide decays mainly by beta emission to calcium, and by electron-capture to an excited state of argon. The electron-capture decay of 40K directly to the ground state of argon has never been...
Extraterrestrial neutrinos can be used as messengers to probe the presence of dark matter particles in the Milky Way. Indeed, sizable fluxes of high-energy neutrinos are expected from pair annihilation and decay of dark matter in regions where it accumulates to a high density. Massive celestial bodies such as the Sun and the very large reservoir at the Galactic Centre are inside the field of...
If the dark matter annihilation cross section is velocity dependent, the dark matter pair-wise relative velocity distribution enters into the calculation of the annihilation signals and the so-called J-factors. Studies of velocity-dependent dark matter annihilation commonly rely on simplified analytic models for the dark matter phase space distribution, which need to be tested against...
Stars whose initial mass is between approximately 150 and 240 M$_\odot$ face a fate of complete explosion in a pair instability supernova (PISN). However, by injecting energy into the star, it may be possible in some cases to avoid this fate. We outline conditions on this energy injection which can lead to the survival or incomplete explosion of the star, and we discuss how dark matter...
Dark matter (DM) particles are predicted to decay into Standard Model particles which would produce signals of neutrinos, gamma-rays, and other secondary particles. Neutrinos provide an avenue to probe astrophysical sources of DM particles. We review the decay of dark matter into neutrinos over a range of dark matter masses from MeV/c2 to ZeV/c2. We examine the expected contributions to the...
Neutron stars (NS) of age >10^9 yrs exhaust thermal and rotational energies and cool down to temperatures below \mathcal{O}(100) K. Accretion of particle dark matter (DM) by such NS can heat them up through kinetic and annihilation processes. This increases the NS surface temperature to a maximum of \sim 2600 K in the best case scenario. The maximum accretion rate depends on the DM ambient...
In the search for particle dark matter (DM) the most prominent model is the Weakly Interacting Massive Particle (WIMP). This work uses Non-Relativistic Effective Operators (NREOs) from corresponding effective field theory (EFT) to describe WIMP DM interactions. The advantage of the NREO formalism is its ability to describe interactions outside the typical spin dependent and spin independent...
The nature of Dark Matter is an ongoing and relevant object of study in astroparticle physics. Despite our best efforts to identify its possible particle properties, the results have been null, which has led to a plethora of models describing viable connections to the Standard Model. In particular, loop models of Dark Matter, like the scotogenic model, have received attention in the last...
In this talk, we present model-independent constraints on dark matter and cosmic neutrinos through gravitational interactions on asteroidal objects. The bounds only rely on the matter density around the trajectories of the asteroids. The new bounds are model-independent but are most meaningful in constraining dark matter and cosmic neutrino scenarios with significant clustering.
We also...
Dark matter candidates can arise from a wide range of extensions to the Standard Model. Simplified models with a small number of new particles allow for the optimisation and interpretation of dark matter and collider experiments, without the need for a UV-complete theory. In this talk, I will discuss the results from a recent GAMBIT study of global constraints on vector-mediated simplified...
The GAPS experiment is designed to conduct a dark matter search by measuring low-energy cosmic-ray antinuclei (antiprotons, antideuterons, antihelium) with a novel detection approach. For the case of antiprotons, a high-statistics measurement in the unexplored low-energy range will be conducted. In contrast, not a single cosmic antideuteron has been detected by any experiment thus far....
Axions and axion-like particles (ALPs) are a theoretically promising dark matter candidate. In the presence of radio emissions from bright astrophysical sources, nonrelativistic ALPs can undergo stimulated decay to two nearly back-to-back photons, giving bright radio sources counterimages ("echoes") in nearly the exact opposite spatial direction. These echoes are spectrally distinct, and...
Light dark sectors can explain the existence of dark matter and, if the new fermions carry lepton number, may also generate light neutrino masses. We revisit models where the dark photon $A^\prime$ couples to multiple generations of dark fermions. The decays $A^\prime$ are semi-visible: they contain visible particles but come accompanied by missing energy. We will show that these models can...
We consider a dark sector containing a pair of almost degenerate states coupled to the Standard Model via a portal interaction. The lightest state can be a dark matter candidate, while the heaviest one is long-lived, and its decays offer new testable signals at accelerator experiments. We study the prospects for the detection of this scenario at proposed LHC experiments (e.g. FASER and...
Precision results on cosmic-ray electrons are presented in the energy range from 0.5 GeV to 2.0 TeV based on 50 million electrons collected by the Alpha Magnetic Spectrometer on the International Space Station. In the entire energy range the electron and positron spectra have distinctly different magnitudes and energy dependences. At medium energies, the electron flux exhibits a significant...
The LUX-ZEPLIN (LZ) experiment is a direct dark matter detector hosted at the Sanford Underground Research Facility in Lead, South Dakota. LZ’s central detector is a dual-phase time projection chamber containing 7-tonnes of liquid xenon. This is aided by a xenon skin detector and a liquid scintillator-based outer detector to veto events inconsistent with dark matter.
Results from LZ’s first...
