The vast majority of the elements heavier than helium are formed in stellar environments through sequences of nuclear reactions and decays. Relevant stellar environments for nucleosynthesis include both quiescent burning as well as explosive environments such as novae, supernovae, X-ray bursts, and neutron star mergers. As part of the global effort to understand the origin of the elements, the...
The slow (s) and rapid (r) neutron capture processes have long been considered to produce nearly the entirety of elements above Fe, but when comparing their yields with spectroscopic data, inconsistencies in abundance arise in the Z=40 region. These differences are expected to be attributable to the intermediate (i) neutron capture process.
Working in weak i-process neutron densities on...
Motivated by fundamental symmetry tests, a measure of large electric dipole moment (EDM) would represent a clear signal of the violation of the CP symmetries. This observation highlights the imbalance in the matter and antimatter observed in our Universe. The Standard Model (SM) predicts an EDM lower than the experimental reach, prompting the need to explore beyond the SM. The $^{199}Hg$...
In the universe, most matter is mainly composed of light elements like hydrogen and helium, which were synthesised shortly after the Big Bang. Elements beyond iron are produced through neutron capture via the r-process or the s-process. However, these processes can’t explain the existence of several neutron-deficient elements, called p-nuclei, especially $^{92,94}$Mo and $^{96,98}$Ru. The $...
Understanding the formation of the heaviest elements has long been a pivotal inquiry and recent progress spurred by LIGO's detection of gravitational waves now lead us to examine kilonovae as crucial markers in unraveling the processes behind the synthesis of those elements. Notably, the emission spectra of MeV gamma rays could lead to strong insight in the identification of individual...
Nuclei away from the line of stability have been found to demonstrate behavior that is inconsistent with the traditional magic numbers of the spherical shell model. This has led to the concept of the evolution of nuclear shell structure in exotic nuclei, and the neutron-rich calcium isotopes are a key testing ground of these theories; there have been conflicting results from various...
The ongoing goal of relativistic heavy-ion collision experiments is to constrain the properties of nuclear media under extreme densities. Mounting evidence gathered from these experiments suggests that a strongly interacting plasma of quarks and gluons – the Quark Gluon Plasma (QGP) – is created within these collisions. The QGP is well described using multi-stage simulations, where...
The MOLLER (Measurement of a Lepton-Lepton Electroweak Reaction) experiment aims to measure the weak mixing angle with unprecedented precession at low momentum transfer. The measurement will be carried out with Jefferson Laboratory's state-of-the-art Continuous Electron Beam Accelerator Facility (CEBAF) to measure the parity violating scattering asymmetry of 11 GeV highly-polarized electrons...
Parity Violating Electron Scattering (PVES) experiments are a powerful tool for exploring physics beyond the Standard Model of particle physics. These experiments, which conduct highly accurate measurements of the parity-violating asymmetry across various kinematic conditions and targets, significantly contribute to advancements in particle, nuclear, and hadronic physics. Achieving precise...
The High Voltage Monolithic Active Pixel Sensors (HVMAPS) will be used as electron detectors in The Measurement of a Lepton-Lepton Electroweak Reaction (MOLLER) experiment. The HVMAPS will map the response across the face of the quartz integrating detectors. Using two commercial GEM detectors, a position calibration system for the MOLLER's HVMAP was commisionned. The pair of of GEMs are...
Of particular interest for nuclear structure and astrophysical processes are nuclides in the vicinity of N=Z=50, where the proton and neutron shells are each full or “magic”. These doubly magic isotopes can give unique insights into nuclear structure due to their doubly magic nucleons which give rise to extraordinary nuclear stability, like high binding energy, and tests of isospin symmetry....
There are many outstanding fundamental questions in nuclear physics that are described in the NSERC Subatomic Physics Long Range Plan. For several of these main research drivers such as " How does nuclear structure emerge from nuclear forces and ultimately from quarks and gluons?", gamma-ray spectroscopy is the investigative tool of choice. However, analysis of data from large-scale gamma-ray...
Particle physics and dark matter experiments using large time projection chambers (TPC) with several square meters of light detectors produce tremendous amounts of data. To retrieve such a high volume of data, traditional copper or kapton-based solutions require significant trade-offs to meet the performances and constraints needed by the physics goals. A novel communication system based on...
SPAD array-based photodetectors are emerging in large-scale photodetector panels because of their appealing characteristics such as compactness, low bias voltages and good photon detection efficiency (PDE). Conventional SiPMs are considered for covering large areas, but the large capacitance of SiPMs brings a serious limitation. They also require an analog readout circuit designed with...
Dark matter (DM) is an undetected form of matter whose existence is supported by numerous astrophysical observations on multiple scales. Since DM constitutes over 85% of the mass of the galaxy, its direct detection is one of the most important fundamental physics concerns today. For a broad region of sub-100KHz (peV) "ultralight" DM (UDM), mechanical sensors are predicted to set the deepest...
The McDonald Institute is dedicated to cultivating an inclusive and diverse environment that prioritizes equity, diversity, inclusion, and Indigenization (EDII) within the realm of astroparticle physics research in Canada. Recognizing the significance of varied perspectives, backgrounds, and experiences, we believe that advancing our understanding of the universe is most effective through...
The observed asymmetry between matter and antimatter in the Universe still awaits for an explanation. If lepton number conservation, a global symmetry of the standard model, is violated, that could help understand it. The most sensitive probe to search for this violation is through a hypothetical decay known as neutrinoless double beta decay. Observation of this decay would prove that...
The NEWS-G experiment searches for low-mass dark matter candidates at SNOLAB in Sudbury, Ontario. This direct dark matter search is performed using a spherical proportional counter filled with low atomic mass gases, such as 98% neon + 2% methane. The detector consists of a grounded copper sphere with a high-voltage anode in the centre, which detects ionization within the gas. The inner surface...
The NEWS-G experiment at SNOLAB uses spherical proportional counters, or SPCs, to detect weakly interacting massive particles (WIMPs), which are a prime candidate for dark matter. Interactions within the gas-filled sphere create a primary ionization. The signal from the resulting electrons is passed through a digitizer and this generates raw pulses that are observed as time-series data....
The Particle Physics Group at the Montreal Tandem Accelerator is currently working on setting up an experiment to verify the existence of the so-called X-17 particle. This supposed particle of mass 17 MeV/$c^2$ was first claimed to be observed by the ATOMKI experiment in the decays of excited $^8Be$ and $^4He$ nuclei to their ground states via internal e+ e- pair creation. The anomaly observed...
PICO-500 is a WIMP dark matter bubble chamber detector in its early stages of construction underground at SNOLAB. It is the upscaled successor of PICO-40L, which is currently operational with the objective of detecting dark matter or improving the world leading spin-dependent WIMP search limits set by PICO-60 in 2016. PICO-500 will have almost an order of magnitude greater sensitivity with a...
The PICO collaboration searches for dark matter using superheated C3F8 in bubble chamber technology. The results of the operation of the PICO-60 detector at SNOLAB set the most stringent direct-detection constraint to date on the weakly interacting massive particle (WIMP)-proton spin-dependent cross section.
PICO-500 is the next-generation detector produced by PICO with a 250 kg live volume....
The SuperCDMS collaboration uses cryogenic silicon and germanium detectors to directly search for dark matter. Among the full payload of 24 detectors are 12 HV detectors. These utilize a bias voltage across the crystal substrate to amplify the phonon signal created from particle energy depositions. We have operated 4 Ge and 2 Si HV detectors in a deep underground environment for the first time...
SuperCDMS SNOLAB will be a direct detection experiment with world-leading sensitivity to low-mass dark matter (DM) that employs cryogenic silicon and germanium calorimeters. SNOLAB detectors are expected to exhibit a non-linear energy response, necessitating calibration signatures across the entire energy range of interest. A calibration method proposed for silicon-based detectors is to use...
The Large Hadron Collider at CERN has provided us with an unprecedented number of proton collisions at unprecedented energies. One of the main motivations of the LHC was the discovery of the Higgs boson, which was achieved in 2012. Now over a decade later, this begs the question: what have we been doing at the LHC since the discovery of the Higgs boson? Together, we will explore the richness...
The ATLAS detector at Large Hadron Collider (LHC) at CERN has collected $140~\mathrm{fb}^{-1}$ of proton-proton collisions over the course of the 2015-2018 data-taking period, allowing for some of the most stringent tests of the Standard Model of particle physics and new measurements of its parameters with unprecedented accuracy. This presentation details the first observation of the...
Many extensions to the Standard Model (SM) predict the existence of strongly interacting dark sectors, which behave similarly to Quantum Chromodynamics (QCD) but interact weakly with SM particles. Depending on the parameters of the dark sector, one potential LLP signature could be that of an "emerging jet" – a spray of particle tracks after proton-proton collision dominantly composed of...
The Large Hadron Collider (LHC) at the Conseil Européen pour la Recherche Nucléaire (CERN) features a 27km ring of superconducting magnets that accelerate protons into extremely high-energy collisions to probe for new physics. Found along the ring is ATLAS (A Toroidal LHC ApparatuS), a cylindrical multi-purpose detector with various subsystems. At the heart of the detector, the electromagnetic...
A search for a novel experimental collider signature called 'Emerging Jets' is presented using the ATLAS experiment at the Large Hadron Collider. This signature is based on a model of 'Dark-QCD' wherein dark quarks will shower and hadronize analogous to quantum chromodynamics (QCD) in the Standard Model (SM). If produced in particle collisions, these dark particles would form dark-jets:...
The ‘Data-Directed Paradigm’ (DDP) is a search methodology that efficiently explores possibilities for new physics within a vast number of spectra featuring smooth-falling Standard Model backgrounds. DDP deviates from the traditional analytical approach by sidestepping the requirement for a simulated or functional-form-based background estimate. Instead, it uses a neural network trained to...
At the Francium Trapping Facility located at TRIUMF our group uses laser cooling and atom trapping techniques to confine Fr and Rb atoms in a magneto-optical trap allowing us to investigate highly forbidden optical transitions in these atoms with precision laser spectroscopy. For Fr, these investigations are important precursors to future atomic parity-violating (APV) experiments. Atomic...
The TRIUMF Ultra Cold Advanced Neutron (TUCAN) Collaboration is developing an apparatus to measure the neutron electric dipole moment (nEDM) to a sensitivity of 10−27 ecm, an order of magnitude improvement over the current best limit. The measurement will be conducted over around 105 experiment cycles using spin-polarized ultracold neutrons produced by the high-intensity TUCAN source in a...
Antimatter remains one of the most vital, yet mysterious areas of particle physics. The deficiency of antimatter in nature, despite its theoretically predicted abundance, leaves questions regarding our understanding of fundamental symmetries. Antihydrogen is the antimatter counterpart of the hydrogen atom, and it provides a simple antimatter system to test these symmetries, such as...
One possible extension to the Standard Model of Particle Physics (SM) is one which provides a mechanism, active in the early universe that has lead to the matter-antimatter asymmetry that we observe today. One of the most prominent proposed solutions to this asymmetry relates this imbalance of matter and antimatter to new sources of CP violation which may manifest, for instance, in permanent...
The detection of dark matter is currently one of the leading challenges in particle physics. The DEAP-3600 experiment, the largest argon dark matter detector in the world, uses 3.3 tonnes of liquid argon and 255 photomultiplier tubes to detect scintillation light produced by a dark matter particle scattering on an argon nucleus. Since the interaction of dark matter scattering on argon is such...
Silicon photomultipliers (SiPMs) are the photo-detection technology of choice for future noble-liquid scintillator rare-event search experiments, both in neutrino-less double beta decay and dark matter. The Light only Liquid Xenon (LoLX) experiment is a small-scale R&D liquid xenon (LXe) detector located at McGill University. LoLX aims to perform detailed characterization of SiPM performance...
Baryon asymmetry of our universe is one of the most important phenomena that drives new physics models. I will summarize the landscape of the BSM physics required to explain this asymmetry and I will discuss the wide variety of experimental observations required to test these models.
Dark photons can oscillate into Standard Model (SM) photons via kinetic mixing. The conversion probability depends sensitively on properties of the ambient background, such as the density and electromagnetic field strength, which cause the SM photon to acquire an in-medium effective mass. Resonances can enhance the conversion probability when there is a level-crossing between the dark photon...
Current experiments investigating the existence of magnetic monopoles and other exotic phenomena at the LHC such as MoEDAL are underway. This has included the search for velocity dependent visible monopoles. The upcoming MAPP experiment will pursue the possible detection of milli-magnetically charged dark monopoles. Many novel extended features of our model are proposed, including dark...
Studying atomic parity violation in weak interactions by using atomic spectroscopy-based techniques plays a vital role in testing the Standard Model on a different momentum scale. In Francium Trapping Facility at TRIUMF, we trap and cool francium atoms in a magneto optic trap and then drive a highly forbidden 7s-8s transition in this trapped radioactive atomic sample of francium. Recently, we...
In the pursuit of unraveling one of the fundamental questions in physics—why the Universe is matter-dominated—one possible approach is to scrutinize the nature of neutrinos through the investigation of neutrinoless double beta ($0\nu\beta\beta$) decay. The detection of $0\nu\beta\beta$ decay would signify lepton number violation in weak processes and confirm the Majorana nature of neutrinos....
The nEXO experiment is being designed to search for neutrino-less double beta decay ($0\nu\beta\beta$) in a 5000 kg liquid xenon time projection chamber (TPC) enriched to the isotope xenon-136. nEXO requires unprecedentedly low radioactive background levels to achieve its desired sensitivity exceeding $10^{28}$ years. External backgrounds are shielded in part by immersing the TPC and its...
Barium-tagging is a technique being developed as a potential upgrade for an experiment called nEXO. The technique aims to identify single ions of the isotope Ba-136 to confirm the decay of its parent nucleus Xe-136. Due to the event localisation capability of the nEXO detector, with Ba-tagging, the detector volume can be probed for Ba-136. Identification of Ba-136 would serve as unambiguous...
Low background noble liquid-based experiments are among the leading world efforts in neutrino science and dark matter search. They rely on the development of large-scale photon counting technologies to detect noble liquid scintillation in the VUV range (argon at 128 nm or xenon at 175 nm) as a mean to quantify, position, and discriminate meaningful events.
The Université de Sherbrooke is...
The Light-Only Liquid Xenon (LoLX) experiment is designed to study scintillation light and characterize the performance of silicon photomultipliers (SiPMs) in a liquid xenon (LXe) medium. To ensure the SiPMs are functioning properly, it is necessary to verify that all of them are submerged. LoLX therefore requires a LXe level sensor. Outgassing requirements, cryogenic temperature, space...
A neutron star is one of the densest objects in the universe. Therefore, studying and understanding binary neutron star mergers can help us to understand the behaviour of ultra-dense matter also used to describe nuclear matter in extreme conditions. During those stellar events, most of the gravitational potential energy is transferred to neutrinos that escape the neutron-rich ejecta, and some...
In many environments, such as the early universe or stars, finite temperature effects modify the properties of particles, including their dispersion relations. In particular, the Standard Model photon acquires an effective mass. Furthermore, collective plasma excitations give rise to a longitudinal mode which is absent in vacuum. The key object to compute the effective in-medium mass of both...
