Operation of a high purity germanium crystal in liquid argon as a Compton suppressed radiation spectrometer

A high purity germanium crystal was operated in liquid argon as a Compton suppressed radiation spectrometer. Spectroscopic quality resolution of less than 1% of the full-width half maximum of full energy deposition peaks was demonstrated. The construction of the small apparatus used to obtain these results is reported. The design concept is to use the liquid argon bath to both cool the germanium crystal to operating temperatures and act as a scintillating veto. The scintillation light from the liquid argon can veto cosmic-rays, external primordial radiation, and gamma radiation that does not fully deposit within the germanium crystal. This technique was investigated for its potential impact on ultra-low background gamma-ray spectroscopy. This work is based on a concept initially developed for future germanium-based neutrinoless double-beta decay experiments.Comment: Paper presented at the SORMA XI Conference, Ann Arbor, MI, May 200

Project 8 Phase III Design Concept

We present a working concept for Phase III of the Project 8 experiment, aiming to achieve a neutrino mass sensitivity of $2~\mathrm{eV}$ ($90~\%$ C.L.) using a large volume of molecular tritium and a phased antenna array. The detection system is discussed in detail.Comment: 3 pages, 3 figures, Proceedings of Neutrino 2016, XXVII International Conference on Neutrino Physics and Astrophysics, 4-9 July 2016, London, U

Results from the Project 8 phase-1 cyclotron radiation emission spectroscopy detector

The Project 8 collaboration seeks to measure the absolute neutrino mass scale by means of precision spectroscopy of the beta decay of tritium. Our technique, cyclotron radiation emission spectroscopy, measures the frequency of the radiation emitted by electrons produced by decays in an ambient magnetic field. Because the cyclotron frequency is inversely proportional to the electron's Lorentz factor, this is also a measurement of the electron's energy. In order to demonstrate the viability of this technique, we have assembled and successfully operated a prototype system, which uses a rectangular waveguide to collect the cyclotron radiation from internal conversion electrons emitted from a gaseous $^{83m}$Kr source. Here we present the main design aspects of the first phase prototype, which was operated during parts of 2014 and 2015. We will also discuss the procedures used to analyze these data, along with the features which have been observed and the performance achieved to date.Comment: 3 pages; 2 figures; Proceedings of Neutrino 2016, XXVII International Conference on Neutrino Physics and Astrophysics, 4-9 July 2016, London, U

Comment on "Evidence for Neutrinoless Double Beta Decay"

We comment on the recent claim for the experimental observation of neutrinoless double-beta decay. We discuss several limitations in the analysis provided in that paper and conclude that there is no basis for the presented claim.Comment: A comment written to Modern Physics Letters A. 4 pages, no figures. Updated version, accepted for publicatio

Double-beta decay of 130^{130}Te to the first 0+^{+} excited state of 130^{130}Xe with CUORICINO

The CUORICINO experiment was an array of 62 TeO$_{2}$ single-crystal bolometers with a total $^{130}$Te mass of $11.3\,$kg. The experiment finished in 2008 after more than 3 years of active operating time. Searches for both $0\nu$ and $2\nu$ double-beta decay to the first excited $0^{+}$ state in $^{130}$Xe were performed by studying different coincidence scenarios. The analysis was based on data representing a total exposure of N($^{130}$Te)$\cdot$t=$9.5\times10^{25}\,$y. No evidence for a signal was found. The resulting lower limits on the half lives are $T^{2\nu}_{1/2}(^{130} Te\rightarrow^{130} Xe^{*})>1.3\times10^{23}\,$y (90% C.L.), and $T^{0\nu}_{1/2}(^{130} Te\rightarrow^{130} Xe^{*})>9.4\times10^{23}\,$y (90% C.L.).Comment: 6 pages, 4 figure

Status of the LUX Dark Matter Search

The Large Underground Xenon (LUX) dark matter search experiment is currently being deployed at the Homestake Laboratory in South Dakota. We will highlight the main elements of design which make the experiment a very strong competitor in the field of direct detection, as well as an easily scalable concept. We will also present its potential reach for supersymmetric dark matter detection, within various timeframes ranging from 1 year to 5 years or more.Comment: 4 pages, in proceedings of the SUSY09 conferenc

CUORE-0 results and prospects for the CUORE experiment

With 741 kg of TeO2 crystals and an excellent energy resolution of 5 keV (0.2%) at the region of interest, the CUORE (Cryogenic Underground Observatory for Rare Events) experiment aims at searching for neutrinoless double beta decay of 130Te with unprecedented sensitivity. Expected to start data taking in 2015, CUORE is currently in an advanced construction phase at LNGS. CUORE projected neutrinoless double beta decay half-life sensitivity is 1.6E26 y at 1 sigma (9.5E25 y at the 90% confidence level), in five years of live time, corresponding to an upper limit on the effective Majorana mass in the range 40-100 meV (50-130 meV). Further background rejection with auxiliary bolometric detectors could improve CUORE sensitivity and competitiveness of bolometric detectors towards a full analysis of the inverted neutrino mass hierarchy. CUORE-0 was built to test and demonstrate the performance of the upcoming CUORE experiment. It consists of a single CUORE tower (52 TeO2 bolometers of 750 g each, arranged in a 13 floor structure) constructed strictly following CUORE recipes both for materials and assembly procedures. An experiment its own, CUORE-0 is expected to reach a sensitivity to the neutrinoless double beta decay half-life of 130Te around 3E24 y in one year of live time. We present an update of the data, corresponding to an exposure of 18.1 kg y. An analysis of the background indicates that the CUORE performance goal is satisfied while the sensitivity goal is within reach.Comment: 10 pages, 3 figures, to appear in the proceedings of NEUTRINO 2014, 26th International Conference on Neutrino Physics and Astrophysics, 2-7 June 2014, held at Boston, Massachusetts, US

CUORE and beyond: bolometric techniques to explore inverted neutrino mass hierarchy

The CUORE (Cryogenic Underground Observatory for Rare Events) experiment will search for neutrinoless double beta decay of $^{130}$Te. With 741 kg of TeO$_2$ crystals and an excellent energy resolution of 5 keV (0.2%) at the region of interest, CUORE will be one of the most competitive neutrinoless double beta decay experiments on the horizon. With five years of live time, CUORE projected neutrinoless double beta decay half-life sensitivity is $1.6\times 10^{26}$ y at $1\sigma$ ($9.5\times10^{25}$ y at the 90% confidence level), which corresponds to an upper limit on the effective Majorana mass in the range 40--100 meV (50--130 meV). Further background rejection with auxiliary light detector can significantly improve the search sensitivity and competitiveness of bolometric detectors to fully explore the inverted neutrino mass hierarchy with $^{130}$Te and possibly other double beta decay candidate nuclei.Comment: Submitted to the Proceedings of TAUP 2013 Conferenc