Conveners
Dark Matter Searches
- Katherine Pachal (TRIUMF)
Dark Matter Searches: theory & experiment
- Erica Caden (SNOLAB)
The Scintillating Bubble Chamber (SBC) experiment is a novel low-background technique aimed at detecting low-mass (0.7-7 GeV/c2) WIMP interactions and coherent scattering of reactor neutrinos (CEvNS). The detector consists of a quartz-jar-filled liquid Argon (LAr), which is spiked with ppm-levels of liquid Xenon (LXe) acting as a wavelength shifter. The target fluid is de-pressurized into a...
The NEWS-G direct dark matter experiment uses spherical proportional counters (SPCs) to search for low mass WIMPs. The next phase of this experiment consists of a large 140 cm diameter SPC, called “SNOGLOBE”, which was recently installed at SNOLAB with improvements to overall detector performance and data quality. Prior to installation at SNOLAB, this detector was commissioned using pure...
The NEWS-G experiment searches for low mass dark matter using spherical proportional counters (SPCs). The primary ionization created by a particle interacting with the gas in the SPC drifts towards a central anode. When the ions approach the anode, the electric field becomes strong enough to trigger secondary ionizations, resulting in an amplified detector signal. In this talk I will present...
DEAP-3600 is a single-phase dark matter experiment searching for the direct detection of the dark matter signal using 3279 kg of liquid argon as the target material. In addition to the elastic interaction of the dark matter candidate, a Weakly Interacting Massive Particle (WIMP), with the argon nuclei, theories also predict the modulation in this signal rate with time due to the motion of the...
Bubble chambers using liquid xenon (and liquid argon) have been operated (resp. planned) by the Scintillating Bubble Chamber (SBC) collaboration for GeV-scale dark matter searches and to detect CEvNS from nuclear reactors. This will require a robust calibration of the nucleation efficiency of low-energy nuclear recoils in these target media. Such a program has been carried out by the PICO...
Axion dark matter (DM) constitutes an oscillating background that violates parity and time-reversal symmetries. Inside piezoelectric crystals, where parity is broken spontaneously, this axion background can result in a mechanical stress. We call this new phenomenon "the piezoaxionic effect". When the frequency of axion DM matches the natural frequency of a bulk acoustic normal mode of the...
The Antarctic Impulse Transient Antenna (ANITA) collaboration have reported observation of two anomalous events with noninverted polarity. These events are proven to be hard to explain in terms of conventional cosmic rays (CRs). We propose that these anomalous events represent the direct manifestation of the
dark matter (DM) annihilation events within the so-called axion quark...
The DEAP-3600 experiment (Dark matter Experiment using Argon Pulseshape discrimination) at SNOLAB in Sudbury, Ontario is searching for dark matter via the elastic scattering of argon nuclei by dark matter particles as they traverse through the detector. The detector uses 255 photomultiplier tubes (PMTs) looking at ~3300kg of liquid argon in a spherical vessel. In addition to being sensitive to...
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 matter fermions bound together by a real scalar field. Composite states that are massive enough source...
In Fall 2019, the NEWS-G experiment used its latest detector, a 140 cm diameter Spherical Proportional Counter (SPC) to search for low mass dark matter at the Laboratoire souterrain de Modane (LSM), in France. When a particle interacts with an atom of gas inside the SPC, the ensuing recoil ionizes the gas and produces primary electrons that drift towards the centre of the sphere due to a...
The Spherical Proportional Counter (SPC) is used in NEWS-G to search for low-mass Weakly Interacting Massive Particles (WIMPs). UV laser and Ar37 calibration data were previously taken at Laboratoire Souterrain de Modane (LSM) with a 1.35m diameter SPC filled with pure CH4 gas. To verify our understanding of the detector behavior and the physics model we use, a simulation of the SPC response...
