Conveners
Dark Matter: Dark Matter 1
- Mark Boulay
Dark Matter: Dark Matter 2
- Ubi Wichoski
Dark Matter: Dark Matter 3
- Ken Clark
Dark Matter: Dark Matter 4
- Pierre Gorel
Dark Matter: Dark Matter 5
- Mark Boulay
Dark Matter: Dark Matter 6
- Ken Clark
Dark Matter: Dark Matter 7
- Pierre Gorel
Dark Matter: Dark Matter 8
- Ubi Wichoski
XENON1T, the largest xenon TPC ever built, is performing the most sensitive direct search for WIMP dark matter on earth. As xenon TPCs become larger, long drift times and extreme fidelity requirements challenge the data acquisition, processing, and modeling. This talk explores how XENON1T dealt with these challenges for its first results, and what this implies for XENON1T's future physics...
PandaX experiment, located at China JinPing underground Laboratory (CJPL), is a 500kg scale liquid xenon dark matter direct detection experiment. With the first 98.7-day data, PandaX-II experiment obtained stringent upper limits on the spin-independent (SI) and spin-dependent (SD) WIMP-nucleon elastic scattering cross sections. Alternative models of dark matter are also explored using this...
A search for dark matter was conducted by looking for an annual modulation signal due to the Earth's rotation around the Sun using XMASS-I detector at Kamioka. It is a single phase Xe detector with 832 kg surrounded by low radioactive 642 PMTs with a water tank for cosmic muon veto. The detector has been performed satiable operation over 3 years with a very high light yield of 15...
DEAP-3600 is a dark matter WIMP (Weakly Interacting Massive Particles) search experiment, which aims to detect nuclear recoils from WIMP scattering in an argon target located $2$ km underground at SNOLAB. At WIMP masses of $100$ GeV, DEAP-3600 has a projected sensitivity of $10^{-46}$ cm$^{2}$ for the spin-independent elastic scattering cross section of WIMPs. The beta emissions from the...
The DEAP-3600 experiment is searching for dark matter with a single phase liquid argon (LAr) target, located at SNOLAB. For a background-free exposure of 3000 kg$\cdot$yr, the projected sensitivity to the spin-independent WIMP-nucleon cross section at 100 GeV/c$^2$ WIMP mass is 10$^{-46}$ cm$^{2}$.
The experimental signature of dark matter interactions is keV-scale argon recoils producing 128...
DarkSide uses dual-phase Liquid Argon Time Projection Chambers to search for WIMP dark matter. The current experiment, DarkSide-50, has a 50-kg-active-mass TPC surrounded by a borated-liquid-scintillator neutron detector and a water Cherenkov detector. DarkSide-50 has been running continuously since 2013, initially with atmospheric argon and then, starting in mid-2015, with argon from...
One technology being examined for future direct dark matter searches is a
single-phase noble liquid detector. The MiniCLEAN experiment is a test of
such an approach, using liquid argon to search for WIMPs via nuclear
recoils. The detector, located at SNOLAB, will have a 500 kg (150 kg)
target (fiducial) mass and is instrumented with cold photomultiplier
tubes. Pulse-shape discrimination...
Over the last two decades, astrophysicists and astronomers have produced compelling evidence on galactic and cosmological scales indicates that ~80% of the matter density of the Universe consists of non-luminous, non-baryonic dark matter. Despite this fact, the composition of the dark matter remains unknown. One compelling candidate for particle dark matter is the Weakly Interacting Massive...
The EDELWEISS collaboration is performing a direct search for WIMP dark matter using an array of up to twenty-four 860g cryogenic germanium detectors equipped with a full charge and thermal signal readout. The experiment is located in the ultra-low radioactivity background of the Modane underground laboratory, in the French-Italian Frejus tunnel. We present the analysis of data obtained in...
The CRESST experiment, located at Laboratori Nazionali del Gran Sasso in Italy, searches for dark matter particles via their elastic scattering off nuclei in a target material.
The CRESST target consists of scintillating CaWO$_4$ crystals, which are operated as cryogenic calorimeters at millikelvin temperatures. Each interaction in the CaWO$_4$ target crystal produces a phonon signal and a...
Liquid argon is known as an excellent target material for WIMP dark matter direct search experiment. Use of its ionization and scintillation signals, and scintillation pulse shape provides strong discrimination between the electron and nuclear events. Relatively small atomic mass (A=40) gives higher nuclear recoil energy for WIMP-Ar nuclear scattering, thus it potentially has higher...
Despite several large-scale direct detection experiments worldwide, dark matter remains elusive. Not favored by theory, the low mass region of the weakly interacting particles parameter-space (<1GeV) has been largely ignored until now, and time has come to broaden the search.
The NEWS-G project builds on the experience gathered with the SEDINE detector, which has been operated for several...
The PICO-60 bubble chamber has concluded its dark matter search runs using a superheated liquid C$_3$F$_8$ target. Its replacement currently under commissioning, PICO-40L, is a redesigned bubble chamber with an inverted vertical orientation. This design allows the replacement of the water buffer with a second fused silica jar acting as a piston. The removal of the buffer fluid is intended to...
The China Dark Matter Experiment (CDEX) aims at direct searches of light Weakly Interacting Massive Particles (WIMPs) at the China Jinping Underground Laboratory (CJPL) with an overburden of about 2400m rock. Results from a prototype CDEX-1 994 g p-type Point Contact Germanium(pPCGe) detector are reported. Research programs are pursued to further reduce the physics threshold by improving...
Millimeter-thick charge-coupled devices (CCDs) are outstanding particle detectors. Although initially developed for near-infrared astronomy, the low pixel noise also makes them the most sensitive detectors to signals from ionizing radiation. By virtue of their very low energy threshold (<100 eV of ionizing energy) and their unique capabilities for background characterization based on their...
We directly measure exceptionally long ($\sim$ms) scintillation lifetimes of tetraphenyl-butadiene, a common wavelength shifter used on surfaces in liquid argon detectors. The magnitude of the scintillation tail relative to the prompt signal is found to differ under alpha, beta, and UV excitation, allowing for pulse-shape discrimination (PSD). Using PSD we show that surface backgrounds from...
Dark matter direct detection experiments rely heavily on calibrations to understand each detector’s response to predicted backgrounds. Certain backgrounds, such as neutrino-electron scatters, cannot be directly calibrated, and so beta- or gamma-decay sources are often used as a proxy. This treatment inherently assumes that interaction type and energy do not affect detector response to electron...
The SABRE (Sodium Iodide with Active Background Rejection) experiment will search for an annually modulating signal from Dark Matter (DM) using an array of ultra-pure NaI(Tl) detectors surrounded by an active scintillator veto to further reduce the intrinsic background. The expected rate of interactions between DM particles and the detector in fact modulates due to Earth’s changing velocity...
The ANAIS (Annual modulation with NaI(Tl) Scintillators) experiment aims at the confirmation of the DAMA/LIBRA signal using the same target and technique at the Canfranc Underground Laboratory (LSC). Several 12.5 kg NaI(Tl) modules produced by Alpha Spectra Inc. have been operated in Canfranc during the last years in various set-ups; an outstanding light collection at the level of 15...
Astrophysical observations give overwhelming evidence for the existence of dark matter. While the DAMA collaboration has asserted for years that they observe a dark matter-induced annual modulation signal in their NaI(Tl)-based detectors, their signal has not been confirmed independently. Moreover, DAMA's observations are inconsistent with those from other direct detection dark matter...
The positive observation of dark matter by the DAMA experiment has to be re-examined by a NaI(Tl) detector since there are multiple negative results shown by Xe experiments. The PICOLON experiment is trying to observe dark matter with multiple highly radio-pure NaI(Tl) scintillator detectors.
In recent a couple years, 3”φx3” and 4”φx3” detectors were constructed for future target of 5”φx5”...
Potassium-40 is a contaminant found in many rare-event searches. Its decay by electron capture to argon-40 emits X-rays and Auger electrons at energies of 3 keV and below, right in the region where direct searches for dark matter expect their signal. Most of the electron capture decays are to an excited state of 40Ar which emits a 1.461 MeV gamma ray allowing identification of the low-energy...
The Jinping Neutrino Experiment will perform an in-depth research on solar neutrinos, geo-neutrinos and supernova relic neutrinos. Many efforts were devoted to the R&D of the experimental proposal. A new type of liquid scintillator, with high light-yield and Cherenkov and scintillation separation capability, is being developed. The assay and selection of low radioactive stainless-steel (SST)...
LUX-ZEPLIN (LZ) is a forthcoming experiment designed to directly detect WIMP dark matter. It aims to detect WIMP interactions with a liquid xenon time projection chamber containing 5.6 tonnes of xenon in the fiducial volume. LZ is projected to have a sensitivity to the spin-independent WIMP-nucleon cross section of 2.3x10^-48 cm^2 for a 40 GeV/c^2 mass WIMP after 1000 days of livetime. An...
LZ will be a 10 ton dual-phase xenon Time Projection Chamber (TPC) searching for WIMP dark matter via direct detection. In order to achieve our desired sensitivity, we require an extremely radiopure environment. Gamma backgrounds originate outside of the bulk xenon and are mitigated by xenon’s self-shielding properties, as well as our position reconstruction and veto capabilities. More...
The Super Cryogenic Dark Matter Search (SuperCDMS) and its predecessor CDMS have been at the forefront of the search for Weakly Interacting Massive dark matter Particles (WIMPs) for close to two decades. Significant improvements in detector technology have opened up the low-mass parameter space ( $^\lt\!\!\!\!_\sim$ 10 GeV/c$^2$) where the experiment broke new ground with the CDMS low...
The planned SuperCDMS SNOLAB dark matter experiment will seek direct detection of WIMP-like dark matter with masses in the 0.5-10 GeV/c$^2$ mass range. The experiment will employ four types of cryogenic radiation detectors sensitive to phonon and ionization signals. At the lowest recoil energies electron recoil backgrounds are expected to limit the cross section reach to ~10$^{-43}$ cm$^2$...
The PICO-500L detector will be a 500 litre bubble chamber designed to search for weakly interacting massive particles (WIMP). The experiment will cover a large range of mass and cross section parameter space, proving a variety of theoretical models. The PICO collaboration has built a well established technology, easily scalable and relatively inexpensive with flexibility to easily exchange...
Liquid xenon is an ideal target material to probe Dark Matter and neutrino physics well beyond the sensitivity of ongoing projects. The DARWIN observatory is a proposed detector with a multitude of physics channels spanning particle, astroparticle, and nuclear physics. DARWIN will probe vanilla WIMPs down to the signal from atmospheric neutrinos, and search for light WIMPs, solar axions,...
Neutron-induced backgrounds are among the dominant backgrounds in low-background experiments. One of the main processes that produce these neutrons is the ($\alpha$,n) reaction occurring in detector components. An accurate understanding of these backgrounds is important for any low-background experiment. In this talk, we will present NeuCBOT, a new tool for calculating ($\alpha$,n) yields and...
Germanium detectors with sub-keV sensitivities [1] offer a unique opportunity to study neutrino interactions and properties [2] as well as to search for light WIMP Dark Matter and axion-like particles [3]. The TEXONO Collaboration has been pursuing this research program at the Kuo-Sheng Neutrino Laboratory (KSNL) in Taiwan. We will highlight our results on neutrino electromagnetic properties,...
Direct dark matter searches are promising techniques to identify the nature of dark matter particles. A variety of experiments have been developed over the past decades, aiming at detecting Weakly Interactive Massive Particles (WIMPs) via their scattering in a detector medium. Exploiting directionality would give a proof of the galactic origin of dark matter making it possible to provide a...
NEWAGE is a direction-sensitive direct dark matter search experiment with a three-dimensional gaseous tracking detector (micro-TPC). Our goals are detection of dark matter - nucleus scattering signal in the micro-TPC and investigation of the characteristics of the kinematics of dark matter in the Galaxy. Our direction-sensitive dark matter search by NEWAGE-0.3b’ has been performed in Kamioka...
In order to perform Directional DM detection, low energy nuclear recoil tracks have to be detected. The MIMAC collaboration has recently reported the first detection of 3D nuclear tracks coming from the Radon progeny confirming the possibility to perform this kind of measurement with an ionization quenching measurement on these heavy nuclei. The nuclear recoils produced by monochromatic...
The axion is a hypothetical particle invented for solving the CP problem in strong interactions.
The XMASS-I detector with 832 kg of natural xenon has the sensitivity for searching for axions produced in the Sun thanks to its low energy threshold and low background.
In the XMASS commissioning run, we obtain the model independent limit on the coupling for mass << 1 keV is g_aee < 5.4 x 10^-11...
The LUX experiment has been searching for direct evidence of rare events including the interactions galactic dark matter. LUX is a 250 kg active liquid-xenon target situated 1.5 km underground at the Sanford Underground Research Facility in Lead, South Dakota (USA).
It is a liquid/gas time projection chamber capable of 3-D position reconstruction and nuclear recoil discrimination. We will...
International Axion Observatory (IAXO) is a new generation axion helioscope aiming to search for solar axions and axion-like particles (ALPs) with a signal to background ratio of about 5 orders of magnitude higher than the one achieved by currently the most sensitive axion helioscope, CAST. IAXO relies on large improvements in magnetic field volume and extensive use of x-ray focusing optics...
XMASS is multi-purpose experiment using a single phase liquid xenon technology located underground at Kamioka Observatory in Japan.
XMASS-I detector aims mainly for direct detection of dark matter particles with 832 kg of liquid xenon.
The key idea to reduce the background at low energies in XMASS is to use liquid xenon itself as a shield. The clean core of the 832 kg liquid xenon volume is...
In this talk, we discuss the effects of a non-negligible threshold energy on our model-independent methods developed for reconstructing WIMP properties by using measured recoil energies in direct Dark Matter detection experiments directly. Our expressions for reconstructing the mass and the (ratios between the) spin-independent and the spin-dependent WIMP-nucleon couplings have been modified....
We consider dark matter models in which the mass splitting between the dark matter particles and their annihilation products is tiny. Compared to the previously proposed Forbidden Dark Matter scenario, the mass splittings we consider are much smaller, and are allowed to be either positive or negative. To emphasize this modification, we dub our scenario "Impeded Dark Matter". We demonstrate...
Many theories of dark matter (DM) predict that DM particles can be captured by stars via scattering on ordinary matter. They subsequently condense into a DM core close to the center of the star and eventually annihilate. In this work, we trace DM capture and annihilation rates throughout the life of a massive star and show that this evolution culminates in an intense annihilation burst...
Dark matter particles interacting via the exchange of very light spin-0 mediators can have large self-interaction rates and obtain their relic abundance from thermal freeze-out. At the same time, these models face strong bounds from direct and indirect probes of dark matter as well as a number of constraints on the properties of the mediator. We investigate whether these constraints can be...
There are a number of papers that calculate how the limits or positive results of current experiments would be if some specific twist is applied to the standard interpretation framework (e.g., SI interactions with f_p \neq f_n). These works are usually not performed by members of the experiments, and therefore make very simple assumptions on experimental details like efficiencies....
The galaxy rotation curve, gravitational lensing and the existence of large scale structure imply that the present Universe is filled with a mysterious form of invisible matter, called “dark matter (DM)”, which is about 27% ( roughly 5 times of visible matter) of the total energy budget. Hitherto the existence of DM has been consolidated via its gravitational interaction in a cosmological...
As is well known, dark matter direct detection experiments will ultimately be limited by a "neutrino floor," due to the scattering of nuclei by MeV neutrinos from, e.g., nuclear fusion in the Sun. Here we point out the existence of a new "neutrino floor" that will similarly limit indirect detection with the Sun, due to high-energy neutrinos from cosmic-ray interactions with the solar...
Dark matter decays or annihilations that produce line-like spectra may be smoking-gun signals. However, even such distinctive signatures can be mimicked by astrophysical or instrumental causes. We show that velocity spectroscopy-the measurement of energy shifts induced by relative motion of source and observer-can separate these three causes with minimal theoretical uncertainties. The...
Axion like particles (ALPs) are fundamental pseudo particles with properties similar to Axions that have been involved to solve the strong CP problem in Quantum Chromodynamics. ALPs can oscillate into photons and vice versa in the presence of an external magnetic field. This oscillation of Photon and ALPs could have important implications for astronomical observations, i.e. a characteristic...
The sub-GeV spectrum of cosmic ray antinuclei is a largely unexplored hunting ground for products of dark matter decay or annihilation. Because the conventional astrophysical background is extremely low, detection of even a few antideuterons in this regime would be a strong hint of a dark matter source. Meanwhile, measuring the low-energy antiproton spectrum will constrain both dark matter...
The AMS-02 experiment has recently released a new measurement of the cosmic-ray antiproton spectrum. Assuming that cold dark matter (CDM) is made of self-annihilating particles, the AMS-02 data can be used to constrain the annihilation cross section. It is known however that CDM structures itself on scales much smaller than typical galaxies. This structuring translates into a very large...
I will discuss how future measurements of infrared emission from nearby neutron stars can be used as a largely model-independent probe of dark matter interactions with Standard Model particles. This relies on a recently discovered effect that even non-annihilating dark matter has on old neutron stars. The resulting sensitivity to dark matter interactions would exceed the reach of many...
The Higgs can couple to SU(2)xU(1)xSU'(2)xU'(1) models in such a way that the diagonal vector-like SU(2)xU(1) corresponds to the electroweak gauge symmetry. This leads to a new class of Higgs portal dark matter models within reach of direct search experiments. I will introduce the corresponding dark matter models and their implications for direct search experiments. If time permits, I will...
The wide range of probes of physics beyond the standard model (BSM) leads to the need for tools that combine experimental results to make the most robust possible statements about the validity of theories of new physics and the preferred regions of their parameter space. In this talk, I will introduce a new code for such analyses: GAMBIT, the Global and Modular BSM Inference Tool. GAMBIT is a...
This work presents indirect searches for dark matter (DM) as WIMPs (Weakly Interacting Massive Particles) using atmospheric neutrino data of Super-Kamiokande-I,-II,–III and -IV (1996-2016). The latest results of the search for WIMP-induced neutrinos from the Sun, the Earth’s core and the Milky Way are discussed.
We search for an excess of neutrinos as compared to the expected level of...
The IceCube Neutrino Observatory searches for a neutrino signal from dark matter self-annihilations in the Sun, the Earth, and the halo of the Milky Way among other targets. The signal neutrinos are identified as events with reconstructed energies and arrival directions that correspond to the distribution expected in dark matter self-annihilations. The latest results from IceCube will be...
The High Altitude Water Cherenkov (HAWC) gamma-ray observatory is a continuously operated, wide field-of-view (FOV) observatory sensitive to 100 GeV - 100 TeV gamma rays and cosmic rays. HAWC has been making observations since summer 2012 and officially commenced data-taking operations with the full detector in March 2015. With a FOV of 2 steradians, HAWC observes 2/3 of the sky in 24 hours...
In a dedicated run where protons from the Fermilab Booster were
delivered directly to the steel beam dump of the Booster Neutrino
Beamline, the MiniBooNE detector was used to search for the
production of dark matter particles via vector-boson mediators,
as predicted by vector portal models of dark matter. In the
scenario that was considered, the interactions of the dark matter
particles are...
