Cryogenic Underground Observatory for Rare Events (CUORE)
CUORE is is a tightly packed array of 988 TeO2 bolometers operated at 10 mK in the Gran Sasso National Underground Laboratory in Italy. The main goal of the experiment is to search for previously undetected neutrinoless double beta decay in 130Te. CUORE also searches for dark matter and other rare, low-energy events. The CUORE group at Yale has been responsible for the design, construction, and commissioning of the CUORE Detector Calibration System, in the analysis and simulation of CUORE and CUORE-0 data, and in research and development for CUPID, the successor to CUORE.
CUORE Upgrade with Particle IDentification (CUPID)
CUPID will use to CUORE infrastructure for a bolometric experiment that is able to operate in the zero-background conditions and explore the inverted hierarchy of neutrino masses, searching for the violation of the lepton number and the Majorana neutrino. The Yale team is currently re designing a muon veto system for CUORE that will assist in reaching the background goals for CUPID.
Daya Bay Reactor Neutrino Experiment (Daya Bay)
Daya Bay is a US-China-Russia collaboration to search for and measure the yet unknown neutrino mixing angle theta13. The experiment is located at the Daya Bay nuclear power plant near Hong Kong, China. The Yale group has overall responsibility in the US for the design and construction of the antineutrino detectors and is involved in data analysis and measurements. Together with the University of Wisconsin Physical Sciences Laboratory, the Yale group oversaw the assembly and installation of the antineutrino detectors at Daya Bay.
Deep Underground Neutrino Experiment (DUNE)
Yale is undertaking R&D for DUNE, a planned neutrino experiment with a detector composed of multiple LArTPCs that is projected to be in operation in 2022. This experiment will send a high energy neutrino beam over a distance of 1,300 km from Fermilab in Batavia, IL to the Sanford Underground Research Facility (SURF) in Lead, South Dakota. Dune will be used to study low-background physics, such as proton decay and supernova detection, to measure the parameters that characterize three-flavor neutrino oscillations, and to study a phenomenon known as CP-violation, which may help explain the matter-antimatter imbalance in the universe and determine the relative neutrino mass-differences.
IceCube is the world’s largest neutrino detector, encompassing a cubic kilometer of ice at depths between 1,450 and 2,450 meters at the South Pole. IceCube uses 5160 photomultiplier tubes (PMTs) to search for neutrinos from the most violent astrophysical sources: events like exploding stars, gamma-ray bursts, and cataclysmic phenomena involving black holes and neutron stars. IceCube is a powerful tool to search for dark matter and could reveal the physical processes associated with the enigmatic origin of the highest energy particles in nature. In addition, exploring the background of neutrinos produced in the atmosphere, IceCube studies the neutrinos themselves; their energies far exceed those produced by accelerator beams.
nEXO is the multi-ton successor to EXO-200 (see past projects), which will search for neutrinoless double beta decay with half-life sensitivity beyond 1028 years. The nEXO project is currently underway, and the detector is being designed and built in the coming years. The Yale group is working on hardware development for the nEXO Photo Detector system, as well as simulation and analysis of the detector response. We are also investigating possible extensions of this technology to the kiloton scale, enabling half life sensitivities possibly as long as 1030 years.
Project 8 utilizes a novel technique dubbed Cyclotron Radiation Spectroscopy (CRES) to perform precision beta-electron spectroscopy from a gaseous Tritium source in an effort to measure the effective neutrino mass. Totaling 9 institutions, the Project 8 collaboration has for the first time successfully measured single-electron radiation directly. This fundamentally new approach to precision beta spectroscopy is set to push the current limit on sensitivity in direct neutrino mass experiments. Project 8 is led by Prof. Karsten Heeger from Wright Laboratory and the physical experiment is located at the University of Washington in Seattle. The Yale team supports the digitization and ongoing development of algorithms in the data analysis, as well works on a detailed Monte Carlo simulation of the CRES experiment to understand and optimize the energy resolution of the detected electrons.
Precision Oscillation and Spectrum Experiment (PROSPECT)
PROSPECT is a reactor neutrino experiment at very short baselines to make a precision measurement of the flux and energy spectrum of antineutrinos emitted from nuclear reactors. PROSPECT searches for the oscillation signature of sterile neutrinos and tests our understanding of the emission of antineutrinos from the fission products in a nuclear reactor. The measurements of PROSPECT will test our understanding of the Standard Model of Particle Physics, deepen our understanding of nuclear processes in a reactor, and help develop technology for the remote monitoring of nuclear reactors for safeguard and non-proliferation.
Search for new Interactions in a Microsphere Precision Levitation Experiment (SIMPLE)
The SIMPLE experiment, located at Wright Lab, is using optically trapped nanoparticles to perform precision measurements of the neutrinos emitted in beta or electron capture decays. By measuring the recoil of the trapped nanoparticle following a decay of a radioactive nucleus implanted into the nanoparticle, the momentum of the neutrino leaving the particle can be determined on an event by event basis. The current limits to sensing this recoil are determined by Heisenberg uncertainty, and quantum sensing techniques are being developed to improve sensitivity to tiny momentum transfers in the experiment. A new optical trapping system is currently under development to perform these searches, and will be able to search for sterile neutrinos in the keV-MeV mass range with orders-of-magnitude better sensitivity to small branching ratios than existing techniques.
Francesco Iachello’s work has been dedicated to the study of symmetries in physics through the introduction of models based on symmetry and their application to physical systems. Prof. Iachello is co-discoverer (with A. Arima) of the interacting boson model of nuclei. He also introduced supersymmetry in nuclei, developed the vibron model of molecules, introduced symmetries at the critical point of phase transitions, and co-introduced the concept of excited states quantum phase transitions. In recent years, Professor Iachello has further developed the theory of double beta decay, with and without the emission of neutrinos. With J. Barea, he provided a calculation of nuclear matrix elements (NME) within the framework of the interacting boson model (IBM-2). With J. Kotila, he provided a calculation of phase space factors (PSF). His current research in neutrino physics is the study of mechanisms of neutrino-less double beta decay other than the mass mechanism, in particular: the emission and reabsorption of hypothetical sterile neutrinos, the emission of a scalar particle (Majoron), and, with L. Graf, the contribution of hitherto unknown dimension-6 and dimension-9 effective operators.