SNOLAB Seminar Series

The Cryogenic Underground Observatory for Rare Events (CUORE), hosted at the Laboratori Nazionali del Gran Sasso in Italy, is the first tonne-scale cryogenic experiment searching for neutrinoless double-beta decay (0nuDBD) of 130Te. The observation of this process would prove that lepton number is not a symmetry of nature and that neutrinos are Majorana particles. CUORE, started in 2017, is currently in stable data taking: a raw exposure of ~ 1 tonne yr has recently been achieved. In this talk, the most recent results of CUORE for the 0nuDBD channel as well as for other physical processes of interest (2nuDBD, decays to excited states,..) will be presented, together with a review of the detector features and performance.

The DAMIC experiment exploits the exceptional energy and spatial resolution of charge coupled devices (CCDs) to search for dark matter particles. We present the latest results from the 11 kg-day
exposure collected with the DAMIC detector at SNOLAB. We build on previous analyses to distinguish between bulk and surface backgrounds to construct a robust radioactive background model down to energies as low as 50 eV. We compare the observed spectrum of events to the background-model prediction to search for an excess bulk signal, as would be expected from dark matter.

The EDELWEISS direct detection experiment uses cryogenic Ge semiconductor detectors to search for sub-GeV dark matter (DM) particles. With its low gap energy, germanium is an excellent target to explore DM particles interactions with nucleons in the sub-GeV range, and DM-electron interactions in the MeV range, as well as search for the absorption of eV-scale dark photons. The collaboration has recently obtained the first Ge-based constraints on sub-MeV dark DM particles interacting with electrons using a 33.4 g Ge cryogenic detector prototype with a 0.53 electron-hole pair (rms) resolution, operated underground at the Laboratoire Souterrain de Modane.
These results will be presented, as well as the EDELWEISS-SubGeV plans to achieve lower threshold and more efficient particle identification at low energy.

Neutrino oscillations have been probed during the last few decades using multiple neutrino sources and experimental set-ups. In recent years, very large volume neutrino telescopes have started contributing to the field. These large and sparsely instrumented detectors observe atmospheric neutrinos for combinations of baselines and energies inaccessible to other experiments. IceCube, the largest neutrino telescope in operation, has used this to measure standard oscillations and place limits on exotic proposals, such as sterile neutrinos. In this talk, I will go over the newest results from IceCube as well as the improvements expected thanks to a new detector upgrade to be deployed in the near future.

Standard descriptions of the Milky Way dark matter halo and the WIMP-nucleus scattering may be oversimplified. As a result, direct detection experiments like DEAP-3600 can miss important features in case of a future signal. Therefore, it is important to have detailed analysis of the diverse dark matter interactions, in addition to the standard spin-independent and -dependent couplings. In this study we made use of a Non-Relativistic Effective Field Theory which is a suitable framework for such purpose since it considers a palette of dark matternucleon interactions expressed in terms of effective operators. This research also examined how current DEAP-3600 limits are modified due to the presence of substructures in the solar neighborhood; such stellar debris have recently been observed by astronomical surveys like the Gaia satellite and they were assumed with some fraction of dark matter. The most important aspect our study reveals is that both particle physics and astrophysics uncertainties need to be treated together since non-linear effects manifest in exclusion curves.

We are going to discuss the physics reach and the experimental challenges
of directional WIMP-like Dark Matter searches, illustrating the concept of the CYGNUS-TPC international collaboration and how the CYGNO effort fits into it.
We are going to present the latest R&D results in the field and discuss future short and long term developments of such techniques, also in the context of solar Neutrinos measurements.

ProtoDUNE-SP is a single-phase liquid argon (LAr) TPC located at CERN’s neutrino platform facility. This detector is a large scale prototype providing, for the first time, a full validation of the use of the membrane tank technology for large dimension cryostats. With more than 2 years of continuous and stable operation, protoDUNE-SP demonstrates the reliability of the LAr TPC technology for the 10-kton fiducial mass detectors for the DUNE experiment. In this talk the design of the prototype will be presented. The TPC and light system detector performances recently published[1] will be also reviewed.

Two of the outstanding open questions in physics are the nature of dark matter and the fundamental nature of neutrinos. DARWIN is a next-generation experiment aiming to reach a dark matter sensitivity limited by the irreducible neutrino backgrounds. The core of the detector will have a 40 ton liquid xenon target operated as a dual-phase time projection chamber. The unprecedented large xenon mass, the exquisitely low radioactive background and the low energy threshold will allow for a diversification of the physics program beyond the search for dark matter particles: DARWIN will be a true low-background, low-threshold astroparticle physics observatory. I will present the status of the project, its science reach, and discuss the main R&D topics.

The CUPID-Mo experiment, currently taking data at the Laboratoire Souterrain de Modane (France), is a demonstrator for CUPID, the next-generation upgrade of the first ton-scale cryogenic 0νββ-search, CUORE. The experiment is searching for 0νββ decay of 100Mo with an array of 20 enriched ~0.2 kg Li2MoO4 crystals. The detectors are operated deep under the Frejus mountain at a depth of 4800 m.w.e. in a dilution refrigerator at ~20 mK. They are complemented by cryogenic Ge light detectors allowing us to distinguish alpha from beta/gamma events by the detection of both heat and scintillation light signals. With a bolometric performance of ~ 7 keV energy resolution (FWHM) at 2615 keV, full alpha-to-beta/gamma separation and excellent radio-purity levels, we operate in the background free regime. For the present analysis, we consider more than one year of data acquired between March 2019 and April 2020. With 2.17 kg x yr of exposure and a high analysis efficiency of ~ 90%, we are able to set a new world leading limit for 0νββ decay of 100Mo. In this seminar, I will present the details of the analysis, the new limit of T1/2 > 1.4 x 1024 yr at 90% c.i. and I will conclude with an outlook on the data taken up to the end of CUPID-Mo operations in July 2020 and further upcoming analyses.

SNO+ is a multi-purpose, low background liquid scintillator detector located in the SNOLAB facility. This talk will present our progress towards the main goal of SNO+: probing the mass and nature of neutrinos through a search for neutrino less double beta decay. By loading large amounts of natural tellurium into a homogeneous liquid scintillator detector SNO+ is pioneering an affordable and extendable approach to this rare decay search with the isotope 130Te. I will also discuss other physics reach of SNO+ including reactor, solar and supernova neutrinos and invisible nucleon decay. I will present the results for previous water phase operations and the current status of scintillator filling, tellurium plant preparation and background studies.

The searches for solving the greatest mysteries of our Universe require ultra-sensitive detectors and an extreme control of the environment and the background in order to detect a rare signal. Over the last decades, technologies have reached such unprecedented sensitivity levels that never-before-seen background signals must be considered. In this talk I will give an overview of the requirements for low background detection and what are the current R&D effortsfor developing new cutting-edge technologies in order to address the common challenges of experiments and for pushing the limits of detector performance.

The discovery of gravitational wave signals from merger events of massive binary-black-hole (BBH) systems have prompted a renewed debate in the scientific community about the existence of primordial black holes (PBHs) of O(1-100) solar masses. These objects may have formed in the early Universe and could constitute a significant portion of the elusive dark matter that, according to standard cosmology, makes up the majority of the matter content in the universe. I will review the most recent developments of this field, with focus on multi-messenger prospects of detection. In the first part of the talk, I will present the prospects of discovery for both a hypothetical PBH population and the guaranteed population of astrophysical isolated black holes in our Galaxy, based on the radio and X-ray emission from the interstellar gas that is being accreted onto them (the “shiny dresses”). A future detection will be possible thanks to the expected performance of forthcoming radio facilities such as SKA and ngVLA. Then, I will turn my attention to scenarios where primordial black holes constitute a sub-dominant component of the dark matter, and study the impact of dark matter mini-spikes that are expected to form around them (the “dark dresses”) on several observables. In this context, I will first present an updated computation of the PBH merger rate as a function of DM fraction and redshift that takes into account the impact of the dark dresses. Then, I will discuss the observational prospects of these dresses in binary systems composed of a stellar-mass and an intermediate-mass black hole: I will show a novel calculation of the dephasing of the gravitational waveform induced by the DM spike, potentially detectable with the LISA space interferometer.DARK AND SHINY DRESSES AROUND BLACK HOLES DANIELE GAGGERO (UAM)July 6, 2020 Zoom Line: https://laurentian.zoom.us/j/92591146494