Session DD: Mini-symposium on Opportunities in Underground Nuclear Physics: I

Overview of Opportunities in Underground Nuclear Physics

The field of deep underground nuclear physics is within an exciting and burgeoning phase, demonstrated by the recent award of the 2105 Nobel Prize in physics for the observation of neutrino oscillations and neutrino flavor change, with new detector systems in construction and deployment to further develop this scientific field. This talk will overview the current status of the fields within deep underground nuclear physics, focusing on the study of astrophysical neutrino sources, the intrinsic nature of the neutrino, and nuclear astrophysics. The opportunities available in these fields in the near-future will also be discussed.   

Commissioning the SNO+ detector

The SNO+ experiment is the successor to the Sudbury Neutrino Observatory (SNO), in which SNO's heavy water is replaced by approximately 780T of liquid scintillator (LAB). The combination of the 2km underground location, the use of ultra-clean materials and the high light-yield of the liquid scintillator means that a low background level and a low energy threshold can be achieved. This creates a new multipurpose neutrino detector with the potential to address a diverse set of physics goals, including the detection of reactor, solar, geo- and supernova neutrinos. A main physics goal of SNO+ is the search for neutrinoless double beta decay. By loading the liquid scintillator with 0.5\% of natural Tellurium, resulting in about 1300kg of $^{130}$Te (isotopic abundance is slightly over 34\%), a competitive sensitivity to the effective neutrino mass can be reached. This talk will present the status of the SNO+ detector, specifically the results and status of the detector commissioning with water.   

Search for Neutrinoless Double Beta Decay with CUORE

The Cryogenic Underground Observatory for Rare Events (CUORE) is an experiment to search for neutrinoless double beta decay ($0\nu\beta\beta$) in $^{130}$Te and other rare processes. Observation of $0\nu\beta\beta$ would establish violation of the lepton number, indicate that neutrinos are Majorana particles, and would provide information about the absolute neutrino mass scale. CUORE, a bolometric detector composed of 988 TeO$_2$ crystals, with the total mass of about 750 kg of natural Tellurium, will start data taking this year in Gran Sasso National Laboratories (LNGS) in Italy. We will discuss the status of the CUORE experiment, and present the most recent results from CUORE-0, a single-tower array of 52 crystals, operated at LNGS between 2013-2015.   

First data of the Majorana Demonstrator

The\textsc{ Majorana }Collaboration is constructing a system containing 44 kg of HPGe detectors to demonstrate the~feasibility and potential of a future tonne-scale experiment capable of probing the neutrino mass scale in the inverted-hierarchy region.~To realize this, a major goal of Majorana Demonstrator is to demonstrate a path forward to achieving a background rate at or below 1 cnt/(ROI-t-y) in the 4 keV region of interest around the Q-value at 2039 keV.~This goal is pursued through a combination of a significant reduction of radioactive impurities in construction materials with analytical methods for background rejection. The analysis tools~are based on run ranking, data reduction, pulse shape analysis, event coincidences, and time correlations. The first data corresponding to the~commissioning~of the \textsc{Demonstrator} analyzed using these techniques will be presented. The cuts developed to reject delayed charge recovery and multisite events will be described.   

The next generation neutrinoless double-beta decay experiment nEXO

The nEXO Collaboration is actively engaged in R&D towards a very large detector for neutrinoless double beta decay of $^{136}$Xe. The nEXO detector is rooted in the current EXO-200 program, which has reached a sensitivity for the half-life of the decay of $1.9\times10^{25}$y with an exposure of 100 kg-y. The baseline nEXO design assumes 5 tonnes of liquid xenon, enriched in the mass 136 isotope, within a large monolithic time projection chamber. The sensitivity goal for nEXO is a neutrinoless double-beta decay half-life sensitivity of $1\times10^{28}$y, covering the inverted neutrino mass hierarchy with 5 years of data. We present the conceptual nEXO detector design, the current status of R&D efforts, and the physics case for the experiment.   

The HALO / HALO-2 Supernova Neutrino Detectors

The Helium and Lead Observatory (HALO) is a dedicated supernova neutrino detector in SNOLAB, which is built from 79 tons of surplus lead and the helium-3 neutron detectors from the SNO experiment. It is sensitive primarily to electron neutrinos, and is thus complementary to water Cerenkov and organic scintillation detectors which are primarily sensitive to electron anti-neutrinos. A comparison of the rates in these complementary detectors will enable a flavor decomposition of the neutrino flux from the next galactic core-collapse supernova. We have tentative ideas to build a 1000-ton HALO-2 detector in the Gran Sasso laboratory by using the lead from the decommissioned OPERA detector. We are exploring several neutron detector technologies to supplement the existing helium-3 detectors. We welcome new collaborators to join us.   

Test of the validity of the spin statistics with X-ray spectroscopy - VIP2 at LNGS Gran Sasso

We are experimentally investigating possible violations of standard quantum mechanics predictions in the Gran Sasso underground laboratory in Italy. We test with high precision the Pauli Exclusion Principle and the collapse of the wave function (collapse models). We present our method of searching for possible small violations of the Pauli Exclusion Principle (PEP) for electrons, through the search for "anomalous" X-ray transitions in copper atoms, produced by "fresh" electrons (brought inside the copper bar by circulating current) which can have the probability to undergo Pauli-forbidden transition to the 1 s level already occupied by two electrons and we describe the VIP2 (VIolation of PEP) experiment under data taking at the Gran Sasso underground laboratories. In this talk the new VIP2 setup installed in the Gran Sasso underground laboratory will be presented. The goal of VIP2 is to test the PEP for electrons with unprecedented accuracy, down to a limit in the probability that PEP is violated at the level of 10E-31. We show preliminary experimental results and discuss implications of a possible violation.