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Muon-induced backgrounds in the CUORICINO experiment

Description: To better understand the contribution of cosmic ray muons to the CUORICINO background, ten plastic scintillator detectors were installed at the CUORICINO siteand operated during the final 3 months of the experiment. From these measurements, an upper limit of 0.0021 counts/(keV.kg.yr) (95percent c.l.) was obtained on the cosmicray induced background in the neutrinoless double beta decay region of interest. The measurements were also compared to Geant4 simulations.
Date: April 15, 2010
Creator: Andreotti, E.; Arnaboldi, C.; Avignone III, F. T.; Balata, M.; Bandac, I.; Barucci, M. et al.
Partner: UNT Libraries Government Documents Department

Neutrinoless Double Beta Decay in Light of SNO Salt Data

Description: In the SNO data from its salt run, probably the most significant result is the consistency with the previous results without assuming the 8B energy spectrum. In addition, they have excluded the maximal mixing at a very high confidence level. This has an important implication on the double beta decay experiments. For the inverted or degenerate mass spectrum, we find bar<m_nu>_ee bar> 0.013 eV at 95percent CL, and the next generation experiments can discriminate Majorana and Dirac neutrinos if the invertedor degenerate mass spectrum will be confirmed by the improvements in cosmology, tritium data beta decay, or long-baseline oscillation experiments.
Date: September 11, 2003
Creator: Murayama, Hitoshi & Pena-Garay, Carlos
Partner: UNT Libraries Government Documents Department

Electrical Signal Path Study and Component Assay for the MAJORANA N-Type Segmented Contact Detector

Description: The purpose of the present electrical signal path study is to explore the various issues related to the deployment of highly-segmented low-background Ge detectors for the MAJORANA double-beta decay experiment. A significant challenge is to simultaneously satisfy competing requirements for the mechanical design, electrical readout performance, and radiopurity specifications from the MAJORANA project. Common to all rare search experiments, there is a very stringent limit on the acceptable radioactivity level of all the electronics components involved. Some of the findings are summarized in this report.
Date: February 24, 2009
Creator: Amman, Mark; Bergevin, Marc; Chan, Yuen-Dat; Detwiler, Jason A.; Fujikawa, Brian .; Lesko, Kevin T. et al.
Partner: UNT Libraries Government Documents Department

A measurement of the 2 neutrino double beta decay rate of Te-130 in the CUORICINO experiment

Description: CUORICINO was a cryogenic bolometer experiment designed to search for neutrinoless double beta decay and other rare processes, including double beta decay with two neutrinos (2{nu}{beta}{beta}). The experiment was located at Laboratori Nazionali del Gran Sasso and ran for a period of about 5 years, from 2003 to 2008. The detector consisted of an array of 62 TeO{sub 2} crystals arranged in a tower and operated at a temperature of #24;10 mK. Events depositing energy in the detectors, such as radioactive decays or impinging particles, produced thermal pulses in the crystals which were read out using sensitive thermistors. The experiment included 4 enriched crystals, 2 enriched with {sup 130}Te and 2 with {sup 128}Te, in order to aid in the measurement of the 2{nu}{beta}{beta} rate. The enriched crystals contained a total of #24;350 g {sup 130}Te. The 128-enriched (130-depleted) crystals were used as background monitors, so that the shared backgrounds could be subtracted from the energy spectrum of the 130- enriched crystals. Residual backgrounds in the subtracted spectrum were fit using spectra generated by Monte-Carlo simulations of natural radioactive contaminants located in and on the crystals. The 2{nu}{beta}{beta} half-life was measured to be T{sup 2{nu}}{sub 1/2} = [9.81{+-} #6;0.96(stat){+-} 0.49(syst)]#2;x10{sup 20} y.
Date: November 3, 2011
Creator: Kogler, Laura
Partner: UNT Libraries Government Documents Department


Description: Summary and Conclusions - It was shown that segmentation and pulse-shape discrimination can improve the discovery sensitivity of a next-gen 0vBB-decay experiment by 90%. - However, when practical aspects are considered (such as instrumenting each segment with front-end electronics), the discovery sensitivity is decreased by 19%. - This has extremely important consequences to proposed next-gen experiments since the two active collaborations have strongly advocated the use of segmented detectors for all or part of the experiment. - New germanium detector technology, currently under development, has demonstrated excellent multi-site background rejection capabilities without the complexity of segmentation or complicated PSD algorithms. - The physically-segmented p-type germanium detector technology has proven to be a useful and practical tool in modern nuclear physics. The PSEG technology deserves further development as it has the potential for use in a variety of applications.
Date: June 2009
Creator: Hossbach, Todd W.
Partner: UNT Libraries Government Documents Department

Monte Carlo Simulation for the Majorana Neutrinoless Double-betaDecay Experiment

Description: The Majorana experiment is a proposed HPGe detector array that will primarily search for neutrinoless double-beta decay and dark matter. It will rely on pulse-shape discrimination and crystal segmentation to suppress backgrounds following careful materials selection. A critical aspect of the design phase of Majorana is a reliable simulation of the detector response, pulse formation, and its radioactive backgrounds. We are developing an adaptable and complete simulation based on GEANT 4 to address these requirements and the requirements of a modern, large collaboration experiment. The salient aspects of the simulation are presented. The Majorana experiment is presented in a parallel poster by Kareem Kazkaz.
Date: January 28, 2005
Creator: Henning, Reyco & Collaboration, Majorana
Partner: UNT Libraries Government Documents Department

Prospects for CUORE and Latest Results from CUORICINO

Description: CUORE (Cryogenic Underground Observatory for Rare Events) is a proposed next generation experiment designed to search for the neutrinoless DBD of {sup 130}Te using a bolometric technique. The present status of the CUORE is presented along with the latest results from its operating prototype, CUORICINO.
Date: January 5, 2006
Creator: Norman, E B
Partner: UNT Libraries Government Documents Department

Are neutrinos their own antiparticles?

Description: We explain the relationship between Majorana neutrinos, which are their own antiparticles, and Majorana neutrino masses. We point out that Majorana masses would make the neutrinos very distinctive particles, and explain why many theorists strongly suspect that neutrinos do have Majorana masses. The promising approach to confirming this suspicion is to seek neutrinoless double beta decay. We introduce a toy model that illustrates why this decay requires nonzero neutrino masses, even when there are both right-handed and left-handed weak currents.
Date: March 1, 2009
Creator: Kayser, Boris
Partner: UNT Libraries Government Documents Department

Taming the Runaway Problem of Inflationary Landscapes

Description: A wide variety of vacua, and their cosmological realization, may provide an explanation for the apparently anthropic choices of some parameters of particle physics and cosmology. If the probability on various parameters is weighted by volume, a flat potential for slow-roll inflation is also naturally understood, since the flatter the potential the larger the volume of the sub-universe. However, such inflationary landscapes have a serious problem, predicting an environment that makes it exponentially hard for observers to exist and giving an exponentially small probability for a moderate universe like ours. A general solution to this problem is proposed, and is illustrated in the context of inflaton decay and leptogenesis, leading to an upper bound on the reheating temperature in our sub-universe. In a particular scenario of chaotic inflation and non-thermal leptogenesis, predictions can be made for the size of CP violating phases, the rate of neutrinoless double beta decay and, in the case of theories with gauge-mediated weak scale supersymmetry, for the fundamental scale of supersymmetry breaking.
Date: March 15, 2006
Creator: Hall, Lawrence J.; Watari, Taizan & Yanagida, T. T.
Partner: UNT Libraries Government Documents Department

Sensitivity of CUORE to Neutrinoless Double-Beta Decay

Description: In this paper, we study the sensitivity of CUORE, a bolometric double-beta decay experiment under construction at the Laboratori Nazionali del Gran Sasso in Italy. Two approaches to the computation of experimental sensitivity are discussed and compared, and the formulas and parameters used in the sensitivity estimates are provided. Assuming a background rate of 10{sup -2} cts/(keV kg y), we find that, after 5 years of live time, CUORE will have a 1#27;{sigma} sensitivity to the neutrinoless double-beta decay half-life of {caret T{sup 0{nu}}{sub 1/2}}(1{sigma}#27;) = 1.6x#2;10{sup 26} y and thus a potential to probe the effective Majorana neutrino mass down to 41-95 meV; the sensitivity at 1.64{sigma}#27;, which corresponds to 90% C.L., will be {caret T{sup 0{nu}}{sub 1/2}(1.64{sigma}#27;}) = 9.5x10{sup 25} y. This range is compared with the claim of observation of neutrinoless double-beta decay in {sup 76}Ge and the preferred range in the neutrino mass parameter space from oscillation results.
Date: November 23, 2011
Creator: CUORE; Alessandria, F.; Andreotti, E.; Ardito, R.; Arnaboldi, C.; Avignone III, F. T. et al.
Partner: UNT Libraries Government Documents Department

Optimization of the Transport Shield for Neutrinoless Double Beta-decay Enriched Germanium

Description: This document presents results of an investigation of the material and geometry choice for the transport shield of germanium, the active detector material used in 76Ge neutrinoless double beta decay searches. The objective of this work is to select the optimal material and geometry to minimize cosmogenic production of radioactive isotopes in the germanium material. The design of such a shield is based on the calculation of the cosmogenic production rate of isotopes that are known to cause interfering backgrounds in 76Ge neutrinoless double beta decay searches.
Date: April 15, 2012
Creator: Aguayo Navarrete, Estanislao; Kouzes, Richard T.; Orrell, John L.; Reid, Douglas J. & Fast, James E.
Partner: UNT Libraries Government Documents Department

DUSEL-related Science at LBNL -- Program and Opportunities

Description: The National Science Foundation is advancing the design of a Deep Underground Science and Engineering Laboratory (DUSEL) at the former Homestake mine in South Dakota. UC Berkeley and LBNL are leading the design effort for the facility and coordinating the definition and integration of the suite of experiments to be coupled to the facility design in the creation of an MREFC (Major Research Equipment and Facility Construction) proposal. The State of South Dakota has marshaled $120M to prepare the site and begin a modest science program at the 4850 ft level. The first physics experiment is anticipated to begin installation in 2009. The current timetable calls for the MREFC Preliminary Design to be assembled by 2010 to be presented to the National Science Board in 2011. This, in turn, indicates that the earliest DUSEL construction start would be FY2013. The MREFC is estimated (before the inclusion of the long baseline neutrino components) at $500--600M, roughly divided evenly between the experimental program and support for the facility. Construction was estimated at 6--8 years. The DOE and NSF are establishing a Joint Oversight Group (JOG) to coordinate the experimental programs and participation in DUSEL. It is anticipated that the JOG would mirror the similar function for the NSF and DOE participation in the LHC, and that DOE-HEP, DOE-NP, and NSF will all participate in the JOG. In parallel with the NSF efforts, DOE-HEP plans to develop a long baseline neutrino program with neutrino beams created at FNAL and aimed at DUSEL. In the P5 report the focus of the program is to pursue CP violation in the lepton sector. The same detectors can also be used for nucleon decay experiments. DOE has indicated that FNAL would be the ''lead lab'' for the long baseline neutrino program and be charged with designing and ...
Date: August 1, 2009
Creator: Bauer, Christian; Detweiler, Jason; Freedman, Stuart; Gilchriese, Murdock; Kadel, Richard; Koch, Volker et al.
Partner: UNT Libraries Government Documents Department

GLADE Global Liquid Argon Detector Experiment: a letter of intent to FNAL

Description: The recent measurements of the {theta}{sub 13} mixing angle, which controls the observable size of any CP violation effects, open a window of opportunity to take advantage of the world's most powerful existing neutrino beam together with recent successes in development of the ultimate detector technology for the detection of electron neutrinos : a liquid argon (LAr) time projection chamber. During this proposed project a 5kt LAr detector (GLADE) will be developed by European groups to be put in a cryostat in the NuMI neutrino beam at Fermi National Accelerator Laboratory in the US and will start taking data in 3-5 years time to address the neutrino mass ordering. The successful fruition of this project, along with nominal exposure at NO{nu}A and T2K, together with information from double beta decay experiments could ascertain that neutrinos are Dirac particles in the next decade.
Date: May 13, 2012
Creator: Thomas, Jennifer
Partner: UNT Libraries Government Documents Department

2007 Nuclear Data Review

Description: The results of a review and evaluation of neutron and non-neutron nuclear data published in the scientific literature are presented. The status of new chemical elements is examined. Data on revised values for the isotopic composition of the elements are reviewed and recommended values are presented. Half-lives of very long-lived nuclides are presented, including double beta decay, double electron capture, long-lived alpha decay and long-lived beta decay. Data from new measurements on the very heavy elements (trans-meitnerium elements) are discussed and tabulated. The first observation of the radioactive decay mode of the free neutron is discussed. New measurements that have expanded the neutron drip line for magnesium and aluminum are discussed. Data on recent neutron cross-section and resonance integral measurements are also discussed.
Date: May 5, 2008
Creator: Holden,N.E.
Partner: UNT Libraries Government Documents Department

Background Characterization for Thermal Ion Release Experiments with 224Ra

Description: The Enriched Xenon Observatory for neutrinoless double beta decay uses {sup 136}Ba identification as a means for verifying the decay's occurrence in {sup 136}Xe. A current challenge is the release of Ba ions from the Ba extraction probe, and one possible solution is to heat the probe to high temperatures to release the ions. The investigation of this method requires a characterization of the alpha decay background in our test apparatus, which uses a {sup 228}Th source that produces {sup 224}Ra daughters, the ionization energies of which are similar to those of Ba. For this purpose, we ran a background count with our apparatus maintained at a vacuum, and then three counts with the apparatus filled with Xe gas. We were able to match up our alpha spectrum in vacuum with the known decay scheme of {sup 228}Th, while the spectrum in xenon gas had too many unresolved ambiguities for an accurate characterization. We also found that the alpha decays occurred at a near-zero rate both in vacuum and in xenon gas, which indicates that the rate was determined by {sup 228}Th decays. With these background measurements, we can in the future make a more accurate measurement of the temperature dependency of the ratio of ions to neutral atoms released from the hot surface of the probe, which may lead to a successful method of Ba ion release.
Date: December 15, 2005
Creator: Kwong, H.; /Stanford U., Phys. Dept.; Rowson, P. & /SLAC
Partner: UNT Libraries Government Documents Department

Majorana DUSEL R&D Final Report

Description: This report summarizes the work performed at PNNL under the project Majorana Neutrinoless Double Beta Decay DUSEL R&D over the period of FY07-FY09.
Date: September 21, 2010
Creator: Fast, James E.; Hoppe, Eric W.; Mintzer, Esther E.; Aalseth, Craig E.; Day, Anthony R.; Gerlach, David C. et al.
Partner: UNT Libraries Government Documents Department

Single Ion Trapping for the Enriched Xenon Observatory

Description: In the last decade, a variety of neutrino oscillation experiments have established that there is a mass difference between neutrino flavors, without determining the absolute neutrino mass scale. The Enriched Xenon Observatory for neutrinoless double beta decay (EXO) will search for the rare decays of xenon to determine the absolute value of the neutrino mass. The experiment uses a novel technique to minimize backgrounds, identifying the decay daughter product in real time using single ion spectroscopy. Here, we describe single ion trapping and spectroscopy compatible with the EXO detector. We extend the technique of single ion trapping in ultrahigh vacuum to trapping in xenon gas. With this technique, EXO will achieve a neutrino mass sensitivity of <m{sub {nu}}> {approx_equal} .010 eV.
Date: March 28, 2006
Creator: Waldman, Samuel J. & /Stanford U., Phys. Dept. /SLAC
Partner: UNT Libraries Government Documents Department

Characterization of Large Area APDs for the EXO-200 Detector

Description: EXO-200 uses 468 large area avalanche photodiodes (LAAPDs) for detection of scintillation light in an ultra-low-background liquid xenon (LXe) detector. We describe initial measurements of dark noise, gain and response to xenon scintillation light of LAAPDs at temperatures from room temperature to 169 K - the temperature of liquid xenon. We also describe the individual characterization of more than 800 LAAPDs for selective installation in the EXO-200 detector.
Date: December 2, 2011
Creator: Neilson, R.; LePort, F.; Pocar, A.; Kumar, K.; Odian, A.; Prescott, C. Y. et al.
Partner: UNT Libraries Government Documents Department

Muon-induced backgrounds in the CUORICINO experiment

Description: To better understand the contribution of cosmic ray muons to the CUORICINO background, ten plastic scintillator detectors were installed at the CUORICINO site and operated during 3 months of the CUORICINO experiment. From these measurements, an upper limit of 0.0021 counts/keV {center_dot} kg {center_dot} yr (95% C.L.) was obtained on the cosmic ray induced background in the neutrinoless double beta decay region of interest. The measurements were compared to Geant4 simulations, which are similar to those that will be used to estimate the backgrounds in CUORE.
Date: November 16, 2009
Creator: Andreotti, E; Arnaboldi, C; Avignone, F T; Balata, M; Bandac, I; Barucci, M et al.
Partner: UNT Libraries Government Documents Department

A research program in neutrino physics, cosmic rays and elementary particles. Progress report for Task A

Description: Physics interests of the group are focused primarily on tests of conservation laws and studies of fundamental interactions between particles. There is also a significant interest in astrophysics and cosmic rays. Task A consists of three experimental programs; a Double-Beta Decay study (currently at the Hoover Dam), a Reactor Neutrino program (until this year at Savannah River), and the IMB Proton Decay experiment in a Cleveland salt mine. Discussion of the research in each area is given.
Date: August 1, 1991
Creator: Reines, F. & Sobel, H.W.
Partner: UNT Libraries Government Documents Department

WMAPping out Neutrino Masses

Description: Recent data from the Wilkinson Microwave Anisotropy Probe (WMAP) place important bounds on the neutrino sector. The precise determination of the baryon number in the universe puts a strong constraint on the number of relativistic species during Big-Bang Nucleosynthesis. WMAP data, when combined with the 2dF Galaxy Redshift Survey (2dFGRS), also directly constrain the absolute mass scale of neutrinos. These results impinge upon a neutrino oscillation interpretation of the result from the Liquid Scintillator Neutrino Detector (LSND).We also note that the Heidelberg-Moscow evidence for neutrinoless double beta decay is only consistent with the WMAP+2dFGRS data for the largest values of the nuclear matrix element.
Date: October 28, 2003
Creator: Pierce, Aaron & Murayama, Hitoshi
Partner: UNT Libraries Government Documents Department

Two neutrino double-beta decay of {sup 100}Mo to the first excited 0{sup +} state in {sup 100}Ru

Description: Double-beta decay from the ground state of {sup 100}Mo to the O{sup +} excited state at 1,130.29 keV in {sup 100}Ru has been observed. A sample of 956q of Mo metal powder isotopically enriched to 98.468% of {sup 100}Mo was counted in a Marinelli geometry with a well shielded, ultralow-background germanium detector. The cascade gamma-rays at 539.53 and 590.76 keV were observed. The resulting decay half-life is 1.1{sub {minus}0.2}{sup +0.3} {times} 10{sup 21} y at 68% CL.
Date: June 1, 1992
Creator: Barabash, A. S.; Avignone, F. T. III; Guerard, C. K.; Brodzinski, R. L.; Miley, H. S.; Reeves, J. H. et al.
Partner: UNT Libraries Government Documents Department

Simulated progress in double-beta decay

Description: A Monte Carlo code has been developed to accurately simulate double-beta decay measurements. Coincident gamma rays, beta spectra, and angular correlations have been added to adequately simulate a complete {sup 100}Mo nuclear decay and provide corrections to experimentally determined detector efficiencies. This code has been used to strip certain low-background spectra obtained in the Homestake gold mine in Lead, SD, for the purpose of extremely sensitive materials assay for the construction of new, large, enriched germanium detectors. Assays as low as 9 {mu}Bq/g of {sup 210}Pb in lead shielding were obtained.
Date: September 1, 1993
Creator: Miley, H. S.; Arthur, R. J. & Avignone, F. T.
Partner: UNT Libraries Government Documents Department

New techniques and results in {sup 76}Ge double-beta decay

Description: Several methods of lowering the background in germanium double-beta decay experiments are discusses. A technique for increasing confidence in double-beta decay measurements by variation of detector enrichment is demonstrated in the case of two-neutrino decay mode of {sup 76}Ge. The impact of cosmic ray spallation in low-background isotopically enriched germanium detectors is examined.
Date: September 1, 1991
Creator: Miley, H. S.; Brodzinski, R. L.; Hensley, W. K.; Reeves, J. H. & Avignone, F. T.
Partner: UNT Libraries Government Documents Department