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Sample records for 76ge neutrinoless double-beta

  1. An investigation of proton pair correlations relevant to the neutrinoless double beta decay of 76Ge

    NASA Astrophysics Data System (ADS)

    Ticehurst, David R.

    The observation of neutrinoless double beta decay (0nubetabeta ) would demonstrate that the neutrino is a Majorana particle and allow determination of its mass by comparing the measured decay rate to the calculated rate. The main uncertainty in the calculation of the 0 nubetabeta rate is due to uncertainties in the nuclear structure models used in the computation of the nuclear matrix elements for the decay process. This project tested the validity of using wavefunctions for the nuclear states involved in the 0nubetabeta process that are based on a first-order application of the Bardeen-Cooper-Schrieffer (BCS) theory of superconductivity. In the BCS approximation, most of the strength for two-nucleon transfer reactions should be for transitions to the 0 + ground state of the final nucleus (i.e., little strength should go to the 0+ excited states). This experiment measured the strength to the first 0+ excited state for the 74Ge( 3He,n)76Se and 76Ge( 3He,n)78Se reactions relative to the strength for transition to the 0+ ground state in selenium. For both nuclei, and at 3He beam energies of 15 and 21 MeV, the observed relative strength for transfer to the first 0+ excited state was less than 13%. This result supports the validity of using the BCS approximation to describe the ground state of both 76Se and 78Se and is consistent with the results of recent ( 3He,n) cross section measurements on 74Ge and 76Ge. In addition, the magnitude and shape of the measured angular distributions suggest that contribution of the sequential two-nucleon transfer process, which is an indicator of long-range nucleon-nucleon correlations, is over-predicted by the DWBA code FRESCO.

  2. The Majorana Demonstrator: Progress towards showing the feasibility of a 76Ge neutrinoless double-beta decay experiment

    SciTech Connect

    Finnerty, P.; Aguayo, Estanislao; Amman, M.; Avignone, Frank T.; Barabash, Alexander S.; Barton, P. J.; Beene, Jim; Bertrand, F.; Boswell, M.; Brudanin, V.; Busch, Matthew; Chan, Yuen-Dat; Christofferson, Cabot-Ann; Collar, J. I.; Combs, Dustin C.; Cooper, R. J.; Detwiler, Jason A.; Doe, P. J.; Efremenko, Yuri; Egorov, Viatcheslav; Ejiri, H.; Elliott, S. R.; Esterline, James H.; Fast, James E.; Fields, N.; Fraenkle, Florian; Galindo-Uribarri, A.; Gehman, Victor M.; Giovanetti, G. K.; Green, M.; Guiseppe, Vincente; Gusey, K.; Hallin, A. L.; Hazama, R.; Henning, Reyco; Hoppe, Eric W.; Horton, Mark; Howard, Stanley; Howe, M. A.; Johnson, R. A.; Keeter, K.; Kidd, M. F.; Knecht, A.; Kochetov, Oleg; Konovalov, S.; Kouzes, Richard T.; LaFerriere, Brian D.; Leon, Jonathan D.; Leviner, L.; Loach, J. C.; Looker, Q.; Luke, P.; MacMullin, S.; Marino, Michael G.; Martin, R. D.; Merriman, Jason H.; Miller, M. L.; Mizouni, Leila; Nomachi, Masaharu; Orrell, John L.; Overman, Nicole R.; Perumpilly, Gopakumar; Phillips, David; Poon, Alan; Radford, D. C.; Rielage, Keith; Robertson, R. G. H.; Ronquest, M. C.; Schubert, Alexis G.; Shima, T.; Shirchenko, M.; Snavely, Kyle J.; Steele, David; Strain, J.; Timkin, V.; Tornow, Werner; Varner, R. L.; Vetter, Kai; Vorren, Kris R.; Wilkerson, J. F.; Yakushev, E.; Yaver, Harold; Young, A.; Yu, Chang-Hong; Yumatov, Vladimir

    2014-03-24

    The Majorana Demonstrator will search for the neutrinoless double-beta decay (0*) of the 76Ge isotope with a mixed array of enriched and natural germanium detectors. The observation of this rare decay would indicate the neutrino is its own anti-particle, demonstrate that lepton number is not conserved, and provide information on the absolute mass-scale of the neutrino. The Demonstrator is being assembled at the 4850 foot level of the Sanford Underground Research Facility in Lead, South Dakota. The array will be contained in a lowbackground environment and surrounded by passive and active shielding. The goals for the Demonstrator are: demonstrating a background rate less than 3 counts tonne -1 year-1 in the 4 keV region of interest (ROI) surrounding the 2039 keV 76Ge endpoint energy; establishing the technology required to build a tonne-scale germanium based double-beta decay experiment; testing the recent claim of observation of 0; and performing a direct search for lightWIMPs (3-10 GeV/c2).

  3. Limits of Majorana neutrino mass from combined analysis of data from 76Ge and 136Xe neutrinoless double beta decay experiments

    NASA Astrophysics Data System (ADS)

    Klimenko, A. A.; Rumyantseva, N. S.

    2017-01-01

    We present effective Majorana neutrino mass limits < m ββ> obtained from the joint analysis of the recently published results of 76Ge and 136Xe neutrinoless double beta decay (0νββ) experiments, which was carried out by using the Bayesian calculations. Nuclear matrix elements (NMEs) used for the analysis are taken from the works, in which NMEs of 76Ge and 136Xe were simultaneously calculated. This reduced systematic errors connected with NME calculation techniques. The new effective Majorana neutrino mass limits < m ββ> less than [85.4-197.0] meV are much closer to the inverse neutrino mass hierarchy region.

  4. Neutrinoless Double Beta Decay

    NASA Astrophysics Data System (ADS)

    Fiorini, Ettore

    2007-06-01

    The recent results showing the presence of neutrino oscillations clearly indicate that the difference between the squared mass of neutrinos of different flavors is different from zero, but are unable to determine the nature and the absolute value of the neutrino mass. Neutrinoless double beta decay (DBD) is at present the most powerful tool to ascertain if the neutrino is a Majorana particle and to determine under this condition the absolute value of its mass. The results already obtained in this lepton violating process will be reported and the two presently running DBD experiments briefly discussed. The future second generation experiments will be reviewed with special emphasis to those already partially approved. In conclusion the peculiar and interdisciplinary nature of these searches will be stressed in their exciting aim to discover if neutrino is Dirac or Majorana particle.

  5. The Majorana Neutrinoless Double-beta Decay Experiment

    NASA Astrophysics Data System (ADS)

    Guiseppe, Vincente

    2008-04-01

    Neutrinoless double-beta decay searches play a major role in determining the effective Majorana neutrino mass, the Majorana nature of neutrinos, and a lepton violating process. The Majorana experiment proposes to assemble an array of HPGe detectors to search for neutrinoless double-beta decay in ^76Ge. Initially, Majorana aims to construct a prototype system containing 60 kg of Ge detectors to demonstrate the potential of a future 1-tonne experiment. The design and potential reach of the prototype system will be presented. This talk will also discuss material purity, detector optimization, background rejection, identification of rare backgrounds, and other key technologies to be utilized in the Majorana experiment.

  6. Correlations and the neutrinoless double beta decay

    SciTech Connect

    Menendez, J.; Poves, A.; Caurier, E.; Nowacki, F.

    2009-11-09

    We explore the influence of the deformation on the nuclear matrix elements of the neutrinoless double beta decay (NME), concluding that the difference in deformation -or more generally on the amount of quadrupole correlations- between parent and grand daughter nuclei quenchs strongly the decay. We discuss how varies the nuclear matrix element of {sup 76}Ge decay when the wave functions of the two nuclei involved in the transition are constrained to reproduce the experimental occupancies. In the Interacting Shell Model description the value of the NME is enhanced about 15% compared to previous calculations, whereas in the QRPA the NME's are reduced by 20%-30%, thus, the discrepancies between both approaches diminish.

  7. The Majorana Neutrinoless Double-Beta Decay Program

    NASA Astrophysics Data System (ADS)

    Guiseppe, Vincente

    2014-09-01

    Neutrinoless double-beta decay searches play a major role in determining the nature of neutrinos, the existence of a lepton violating process, and the effective Majorana neutrino mass. The Majorana Collaboration is assembling an array of high purity Ge detectors to search for neutrinoless double-beta decay in 76Ge. The Majorana Demonstrator, containing 40 kg (30 kg enriched in 76Ge) of Ge detectors, is currently being constructed and commissioned at the Sanford Underground Research Facility in Lead, South Dakota. The initial goals are to demonstrate the required background and scalability of a Ge-based, tonne-scale experiment. The status and potential physics reach of the Majorana Demonstrator experiment will be presented. Neutrinoless double-beta decay searches play a major role in determining the nature of neutrinos, the existence of a lepton violating process, and the effective Majorana neutrino mass. The Majorana Collaboration is assembling an array of high purity Ge detectors to search for neutrinoless double-beta decay in 76Ge. The Majorana Demonstrator, containing 40 kg (30 kg enriched in 76Ge) of Ge detectors, is currently being constructed and commissioned at the Sanford Underground Research Facility in Lead, South Dakota. The initial goals are to demonstrate the required background and scalability of a Ge-based, tonne-scale experiment. The status and potential physics reach of the Majorana Demonstrator experiment will be presented. We acknowledge support from the Office of Nuclear Physics in the DOE Office of Science, the Particle and Nuclear Astrophysics Program of the National Science Foundation and the Russian Foundation for Basic Research.

  8. Majorana neutrino masses and the neutrinoless double-beta decay

    SciTech Connect

    Faessler, A.

    2006-12-15

    Neutrinoless double-beta decay is forbidden in the Standard Model of electroweak and strong interaction but allowed in most Grand Unified Theories (GUTs). Only if the neutrino is a Majorana particle (identical with its antiparticle) and if it has a mass is neutrinoless double-beta decay allowed. Apart from one claim that the neutrinoless double-beta decay in {sup 76}Ge is measured, one has only upper limits for this transition probability. But even the upper limits allow one to give upper limits for the electron Majorana neutrino mass and upper limits for parameters of GUTs and the minimal R-parity-violating supersymmetric model. One further can give lower limits for the vector boson mediating mainly the right-handed weak interaction and the heavy mainly right-handed Majorana neutrino in left-right symmetric GUTs. For that, one has to assume that the specific mechanism is the leading one for neutrinoless double-beta decay and one has to be able to calculate reliably the corresponding nuclear matrix elements. In the present work, one discusses the accuracy of the present status of calculating of the nuclear matrix elements and the corresponding limits of GUTs and supersymmetric parameters.

  9. Ultralow-background study of neutrinoless double. beta. decay of /sup 76/Ge; new limit on the Majorana mass of. nu. /sub e/

    SciTech Connect

    Avignone F.T. III; Brodzinski, R.L.; Brown, D.P.; Evans J.C. Jr.; Hensley, W.K.; Miley, H.S.; Reeves, J.H.; Wogman, N.A.

    1985-05-27

    A lower limit of 1.16 x 10/sup 23/ yr (1sigma) is reported for the half-life of no-neutrino ..beta../sup -/..beta../sup -/ decay of /sup 76/Ge which results from 3763 h of counting with an ultralow-background, 135-cm/sup 3/ prototype detector located 1438 m underground. A limit of 1.7 x 10/sup 23/ yr (1sigma) results from the best combination of our data with that from other experiments. Straightforward application of shell-model matrix elements to this limit implies that <3.2 eV (1sigma).

  10. The Majorana Demonstrator Neutrinoless Double-beta Decay Experiment

    NASA Astrophysics Data System (ADS)

    Guiseppe, V. E.

    2012-03-01

    Neutrinoless double-beta decay searches play a major role in determining the nature of neutrinos, the existence of a lepton violating process, and the effective Majorana neutrino mass. The Majorana Collaboration is assembling an array of HPGe detectors to search for neutrinoless double-beta decay in ^76Ge. Our proposed method uses the well-established technique of searching for neutrinoless double-beta decay in high purity Ge-diode radiation detectors that play both roles of source and detector. The use of p-type point contact Ge detectors present advances in background rejection and a significantly lower energy threshold than conventional Ge detectors. The lower energy threshold opens up a broader and exciting physics program including searches for dark matter and axions concurrent with the double-beta decay search. Initially, Majorana is constructing a prototype module to demonstrate the potential of a future 1-tonne experiment. The status and potential physics reach of the Majorana Demonstrator module will be presented.

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

    SciTech Connect

    Aguayo Navarrete, Estanislao; Kouzes, Richard T.; Orrell, John L.; Reid, Douglas J.; Fast, James E.

    2012-04-15

    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.

  12. The MAJORANA experiment: an ultra-low background search for neutrinoless double-beta decay

    SciTech Connect

    Phillips, D.; Aguayo Navarrete, Estanislao; Avignone, Frank T.; Back, Henning O.; Barabash, Alexander S.; Bergevin, M.; Bertrand, F.; Boswell, M.; Brudanin, V.; Busch, Matthew; Chan, Yuen-Dat; Christofferson, Cabot-Ann; Collar, J. I.; Combs, Dustin C.; Cooper, R. J.; Detwiler, Jason A.; Doe, Peter J.; Efremenko, Yuri; Egorov, Viatcheslav; Ejiri, H.; Elliott, Steven R.; Esterline, James H.; Fast, James E.; Fields, N.; Finnerty, P.; Fraenkle, Florian; Gehman, Victor; Giovanetti, G. K.; Green, Matthew P.; Guiseppe, Vincente; Gusey, K.; Hallin, A. L.; Hazama, R.; Henning, Reyco; Hime, Andrew; Hoppe, Eric W.; Horton, Mark; Howard, Stanley; Howe, M. A.; Johnson, R. A.; Keeter, K.; Keller, C.; Kidd, Mary; Knecht, A.; Kochetov, Oleg; Konovalov, S.; Kouzes, Richard T.; LaFerriere, Brian D.; LaRoque, B. H.; Leon, Jonathan D.; Leviner, L.; Loach, J. C.; MacMullin, S.; Marino, Michael G.; Martin, R. D.; Mei, Dong-Ming; Merriman, Jason H.; Miller, M. L.; Mizouni, Leila; Nomachi, Masaharu; Orrell, John L.; Overman, Nicole R.; Poon, Alan; Perumpilly, Gopakumar; Prior, Gersende; Radford, D. C.; Rielage, Keith; Robertson, R. G. H.; Ronquest, M. C.; Schubert, Alexis G.; Shima, T.; Shirchenko, M.; Snavely, Kyle J.; Steele, David; Strain, J.; Thomas, K.; Timkin, V.; Tornow, W.; Vanyushin, I.; Varner, R. L.; Vetter, Kai; Vorren, Kris R.; Wilkerson, J. F.; Wolfe, B. A.; Yakushev, E.; Young, A.; Yu, Chang-Hong; Yumatov, Vladimir; Zhang, C.

    2012-12-01

    The observation of neutrinoless double-beta decay would resolve the Majorana nature of the neutrino and could provide information on the absolute scale of the neutrino mass. The initial phase of the Majorana Experiment, known as the Demonstrator, will house 40 kg of Ge in an ultra-low background shielded environment at the 4850' level of the Sanford Underground Laboratory in Lead, SD. The objective of the Demonstrator is to validate whether a future 1-tonne experiment can achieve a background goal of one count per tonne-year in a narrow region of interest around the 76Ge neutrinoless double-beta decay peak.

  13. Search for neutrinoless double beta decay

    NASA Astrophysics Data System (ADS)

    Ostrovskiy, Igor; O'Sullivan, Kevin

    2016-06-01

    We review current experimental efforts to search for neutrinoless double beta decay (0νββ). A description of the selected leading experiments is given and the strongest recent results are compared in terms of achieved background indexes (BI) and limits on effective Majorana mass. A combined limit is also shown. The second part of the review covers next generation experiments, highlighting the challenges and new technologies that may be necessary to achieve a justifiable discovery potential. A potential synergy with direct dark matter searches, which could be an especially prudent strategy in case the axial vector coupling constant is quenched in 0νββ decay, is emphasized.

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

    SciTech Connect

    Miley, H.S.; Brodzinski, R.L.; Hensley, W.K.; Reeves, J.H.; Avignone, F.T.

    1991-09-01

    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.

  15. New techniques and results in sup 76 Ge double-beta decay

    SciTech Connect

    Miley, H.S.; Brodzinski, R.L.; Hensley, W.K.; Reeves, J.H. ); Avignone, F.T. . Dept. of Physics)

    1991-09-01

    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.

  16. Neutrinoless double beta decay search with SNO+

    NASA Astrophysics Data System (ADS)

    Lozza, V.

    2014-01-01

    The SNO+ experiment is the follow up of SNO. The detector is located 2 km underground in the Vale Canada Ltd.'s Creighton Mine near Sudbury, Ontario, Canada. The active volume of the detector consists of 780 tonnes of Linear Alkyl Benzene (LAB) in an acrylic vessel of 12 m diameter, surrounded by about 9500 PMTs. The main goal of the SNO+ experiment is the search for neutrinoless double beta decay of 130Te. With an initial loading of 0.3% of natural tellurium (nearly 800 kg of 130Te), it is expected to reach a sensitivity on the effective Majorana neutrino mass of about 100 meV after several years of data taking. Designed as a general purpose neutrino experiment, other exciting physical goals can be explored, like the measurement of reactor neutrino oscillations and geo-neutrinos in a geologically-interesting location, watch of supernova neutrinos and studies of solar neutrinos. A first commissioning phase with water filled detector will start at the end of 2013, while the double beta decay phase will start in 2015.

  17. Neutrinoless double beta decay and neutrino mass

    NASA Astrophysics Data System (ADS)

    Vergados, J. D.; Ejiri, H.; Šimkovic, F.

    2016-11-01

    The observation of neutrinoless double beta decay (DBD) will have important consequences. First it will signal that lepton number is not conserved and the neutrinos are Majorana particles. Second, it represents our best hope for determining the absolute neutrino mass scale at the level of a few tens of meV. To achieve the last goal, however, certain hurdles have to be overcome involving particle, nuclear and experimental physics. Particle physics is important since it provides the mechanisms for neutrinoless DBD. In this review, we emphasize the light neutrino mass mechanism. Nuclear physics is important for extracting the useful information from the data. One must accurately evaluate the relevant nuclear matrix elements (NMEs), a formidable task. To this end, we review the recently developed sophisticated nuclear structure approaches, employing different methods and techniques of calculation. We also examine the question of quenching of the axial vector coupling constant, which may have important consequences on the size of the NMEs. From an experimental point of view it is challenging, since the life times are extremely long and one has to fight against formidable backgrounds. One needs large isotopically enriched sources and detectors with good energy resolution and very low background.

  18. Current and future searches for neutrinoless double beta decay

    NASA Astrophysics Data System (ADS)

    Dolinski, Michelle J.

    2016-09-01

    With the discovery of neutrino oscillations and neutrino mass, it has become a pressing question whether neutrinos have distinct antiparticle states. The most practical experimental approach to answering this question is the search for neutrinoless double beta decay, a version of a rare nuclear process that would violate lepton number conservation. The observation of neutrinoless double beta decay would prove that neutrinos are their own antiparticles. Neutrinoless double beta decay experiments deploy large source masses consisting of a select few (usually enriched) isotopes of interest. Detectors must achieve extremely low levels of radioactive background to detect this rare decay. I will report on recent searches for neutrinoless double beta decay and discuss the technical challenges that the next generation of experiments will overcome.

  19. Extended operator expansion method for neutrinoless double beta decay

    NASA Astrophysics Data System (ADS)

    Hirsch, M.; Kadowaki, O.; Klapdor-Kleingrothaus, H. V.; Muto, K.; Oda, T.

    1995-03-01

    Reliable calculations of nuclear matrix elements are a prerequisite for the determination of the effective neutrino mass and other particle physics parameters from neutrinoless double beta decay. Here, the operator expansion method is improved by including Coulomb, tensor and central interactions simultaneously. Furthermore, the formalism of the OEM is extended to those matrix elements necessary to extract the right-handed parameters < λ > and < η > from 0 νββ decay. OEM includes the dependence of the nuclear matrix elements on the intermediate states implicitly and can therefore be understood as a step beyond the closure approximation. Numerical studies are carried out for the isotope76Ge combining the OEM expressions with ground-state wave functions calculated within a proton-neutron quasiparticle Random Phase Approximation (pn-QRPA) model. The influence and relative importance of central, tensor and Coulomb interactions is investigated. Within the OEM, contributions from the Coulomb force are found to be negligible in 0 νββ decay, while the tensor force leads to a moderate change of the results, of the order of (10 30)%, giving a better agreement between sets of calculations which employ different NN-interactions. Generally, results of the OEM+QRPA calculation are similar to previous calculations of 0 νββ decay matrix elements, indicating that 0 νββ decay is not sensitive to model approximations and might therefore be more accurately calculated than the strongly suppressed 2 νββ decay matrix elements.

  20. LBL/UCSB /sup 76/Ge double beta decay experiment: first results

    SciTech Connect

    Goulding, F.S.; Cork, C.P.; Landis, D.A.; Luke, P.N.; Madden, N.W.; Malone, D.F.; Pehl, R.H.; Smith, A.R.; Caldwell, D.O.; Eisberg, R.M.

    1984-10-01

    A paper given at the IEEE Nuclear Science Symposium last year presented the scientific justification for this experiment and discussed the design of the detector system. At the present time two of the dual detector systems (i.e., four out of a final total of eight detectors) are operating in the complete active/passive shield in the low background laboratory at LBL. Early results (1620 h) of an experiment using two detectors yield a limit of 4 x 10/sup 22/ years (68% confidence) for the half life of the neutrinoless double beta decay (..beta beta../sub o nu/) of /sup 76/Ge. Although this experiment was carried out above ground, the result approaches those achieved by other groups in deep underground laboratories. Based on studies of the origins of background in our system, we hope to reach a limit of 3 x 10/sup 23/ years (or more) in a two month/four detector experiment to be carried out soon in an underground facility.

  1. Status of the Battelle-Carolina /sup 76/Ge double beta decay experiment

    SciTech Connect

    Moore, R.S.; Avignone, F.T. III; Brodzinski, R.L.; Brown, D.P.; Evans, J.C. Jr.; Hensley, W.K.; Reeves, J.H.; Wogman, N.A.

    1983-09-01

    A new detector for the measurement of /sup 76/Ge double beta decay is described. The detector system will consist of a 1440 cm/sup 3/ mosaic Ge detector with anticoincidence shielding, and the experiment will be performed deep underground. 12 references. (WHK)

  2. Theory of neutrinoless double-beta decay

    NASA Astrophysics Data System (ADS)

    Vergados, J. D.; Ejiri, H.; Šimkovic, F.

    2012-10-01

    Neutrinoless double-beta decay, which is a very old and yet elusive process, is reviewed. Its observation will signal that the lepton number is not conserved and that the neutrinos are Majorana particles. More importantly it is our best hope for determining the absolute neutrino-mass scale at the level of a few tens of meV. To achieve the last goal certain hurdles must be overcome involving particle, nuclear and experimental physics. Nuclear physics is important for extracting useful information from the data. One must accurately evaluate the relevant nuclear matrix elements—a formidable task. To this end, we review the sophisticated nuclear structure approaches which have recently been developed, and which give confidence that the required nuclear matrix elements can be reliably calculated employing different methods: (a) the various versions of the quasiparticle random phase approximations, (b) the interacting boson model, (c) the energy density functional method and (d) the large basis interacting shell model. It is encouraging that, for the light neutrino-mass term at least, these vastly different approaches now give comparable results. From an experimental point of view it is challenging, since the life times are long and one has to fight against formidable backgrounds. One needs large isotopically enriched sources and detectors with high-energy resolution, low thresholds and very low background. If a signal is found, it will be a tremendous accomplishment. The real task then, of course, will be the extraction of the neutrino mass from the observations. This is not trivial, since current particle models predict the presence of many mechanisms other than the neutrino mass, which may contribute to or even dominate this process. In particular, we will consider the following processes: The neutrino induced, but neutrino-mass independent contribution. Heavy left and/or right-handed neutrino-mass contributions. Intermediate scalars (doubly charged, etc

  3. Theory of neutrinoless double-beta decay.

    PubMed

    Vergados, J D; Ejiri, H; Simkovic, F

    2012-10-01

    Neutrinoless double-beta decay, which is a very old and yet elusive process, is reviewed. Its observation will signal that the lepton number is not conserved and that the neutrinos are Majorana particles. More importantly it is our best hope for determining the absolute neutrino-mass scale at the level of a few tens of meV. To achieve the last goal certain hurdles must be overcome involving particle, nuclear and experimental physics. Nuclear physics is important for extracting useful information from the data. One must accurately evaluate the relevant nuclear matrix elements--a formidable task. To this end, we review the sophisticated nuclear structure approaches which have recently been developed, and which give confidence that the required nuclear matrix elements can be reliably calculated employing different methods: (a) the various versions of the quasiparticle random phase approximations, (b) the interacting boson model, (c) the energy density functional method and (d) the large basis interacting shell model. It is encouraging that, for the light neutrino-mass term at least, these vastly different approaches now give comparable results. From an experimental point of view it is challenging, since the life times are long and one has to fight against formidable backgrounds. One needs large isotopically enriched sources and detectors with high-energy resolution, low thresholds and very low background. If a signal is found, it will be a tremendous accomplishment. The real task then, of course, will be the extraction of the neutrino mass from the observations. This is not trivial, since current particle models predict the presence of many mechanisms other than the neutrino mass, which may contribute to or even dominate this process. In particular, we will consider the following processes: The neutrino induced, but neutrino-mass independent contribution. Heavy left and/or right-handed neutrino-mass contributions. Intermediate scalars (doubly charged, etc

  4. The Majorana Demonstrator: A search for neutrinoless double-beta decay of germanium-76

    SciTech Connect

    Elliott, S. R.; Boswell, M.; Goett, J.; Rielage, K.; Ronquest, M. C.; Xu, W.; Abgrall, N.; Chan, Y-D.; Hegai, A.; Martin, R. D.; Mertens, S.; Poon, A. W. P.; Aguayo, E.; Fast, J. E.; Hoppe, E. W.; Kouzes, R. T.; LaFerriere, B. D.; Orrell, J. L.; Overman, N. R.; Soin, A.; and others

    2013-12-30

    The MAJORANA collaboration is searching for neutrinoless double beta decay using {sup 76}Ge, which has been shown to have a number of advantages in terms of sensitivities and backgrounds. The observation of neutrinoless double-beta decay would show that lepton number is violated and that neutrinos are Majorana particles and would simultaneously provide information on neutrino mass. Attaining sensitivities for neutrino masses in the inverted hierarchy region, 15 - 50 meV, will require large, tonne-scale detectors with extremely low backgrounds, at the level of ∼1 count/t-y or lower in the region of the signal. The MAJORANA collaboration, with funding support from DOE Office of Nuclear Physics and NSF Particle Astrophysics, is constructing the DEMONSTRATOR, an array consisting of 40 kg of p-type point-contact high-purity germanium (HPGe) detectors, of which ∼30 kg will be enriched to 87% in {sup 76}Ge. The DEMONSTRATOR is being constructed in a clean room laboratory facility at the 4850' level (4300 m.w.e.) of the Sanford Underground Research Facility (SURF) in Lead, SD. It utilizes a compact graded shield approach with the inner portion consisting of ultra-clean Cu that is being electroformed and machined underground. The primary aim of the DEMONSTRATOR is to show the feasibility of a future tonne-scale measurement in terms of backgrounds and scalability.

  5. Complementarity of Neutrinoless Double Beta Decay and Cosmology

    SciTech Connect

    Dodelson, Scott; Lykken, Joseph

    2014-03-20

    Neutrinoless double beta decay experiments constrain one combination of neutrino parameters, while cosmic surveys constrain another. This complementarity opens up an exciting range of possibilities. If neutrinos are Majorana particles, and the neutrino masses follow an inverted hierarchy, then the upcoming sets of both experiments will detect signals. The combined constraints will pin down not only the neutrino masses but also constrain one of the Majorana phases. If the hierarchy is normal, then a beta decay detection with the upcoming generation of experiments is unlikely, but cosmic surveys could constrain the sum of the masses to be relatively heavy, thereby producing a lower bound for the neutrinoless double beta decay rate, and therefore an argument for a next generation beta decay experiment. In this case as well, a combination of the phases will be constrained.

  6. Extra dimensions and neutrinoless double beta decay experiments

    NASA Astrophysics Data System (ADS)

    Góźdź, Marek; Kamiński, Wiesław A.; Faessler, Amand

    2005-05-01

    The neutrinoless double beta decay is one of the few phenomena, belonging to the nonstandard physics, which is extensively being sought for in experiments. In the present paper the link between the half-life of the neutrinoless double beta decay and theories with large extra dimensions is explored. The use of the sensitivities of currently planned 0ν2β experiments: DAMA, CANDLES, COBRA, DCBA, CAMEO, GENIUS, GEM, MAJORANA, MOON, CUORE, EXO, and XMASS, gives the possibility for a nondirect “experimental” verification of various extra dimensional scenarios. We discuss also the results of the Heidelberg-Moscow Collaboration. The calculations are based on the Majorana neutrino mass generation mechanism in the Arkani-Hamed-Dimopoulos-Dvali model.

  7. Disentangling the various Mechanisms of neutrinoless double beta decay to extract the neutrino mass

    NASA Astrophysics Data System (ADS)

    Vergados, J. D.

    2011-12-01

    It is well known that there exist many mechanisms that may contribute to neutrinoless double beta decay. By exploiting the fact that the associated nuclear matrix elements are target dependent we show that, given definite experimental results on a sufficient number of targets, one can determine or sufficiently constrain all lepton violating parameters including the mass term. As a specific example we show that, given the observation of the 0νββ-decay in three different nuclei, e.g. 76Ge, 100Mo and 130Te, and assuming just three active lepton number violating parameters, e.g. light and heavy neutrino mass mechanisms in left handed currents as well as R-parity breaking SUSY mechanism, one may determine all lepton violating parameters, provided that they are relatively real.

  8. Non-collapsing renormalized QRPA with proton-neutron pairing for neutrinoless double beta decay

    NASA Astrophysics Data System (ADS)

    Simkovic, F.; Schwieger, J.; Veselský, M.; Pantis, G.; Faessler, Amand

    1997-02-01

    Using the renormalized quasiparticle random phase approximation (RQRPA), we calculate the light neutrino mass mediated mode of neutrinoless double beta decay (0νββ-decay) of 76Ge, 100Mo, 128Te and 130Te. Our results indicate that the simple quasiboson approximation is not good enough to study the 0νββ-decay, because its solutions collapse for physical values of gpp. We find that extension of the Hilbert space and inclusion of the Pauli principle in the QRPA with proton-neutron pairing, allows us to extend our calculations beyond the point of collapse, for physical values of the nuclear force strength. As a consequence one might be able to extract more accurate values on the effective neutrino mass by using the best available experimental limits on the half-life of 0νββ-decay.

  9. Double-beta-decay Q values of {sup 74}Se and {sup 76}Ge

    SciTech Connect

    Mount, Brianna J.; Redshaw, Matthew; Myers, Edmund G.

    2010-03-15

    The atomic masses of {sup 74}Ge, {sup 74}Se, {sup 76}Ge, and {sup 76}Se have been determined from cyclotron frequency ratios of pairs of ions simultaneously trapped in a cryogenic Penning trap. Allowing for cancellation of systematic errors in the mass differences between isobars, we determine the Q value for double-electron capture of {sup 74}Se to be 1209.240(7) keV, and the Q value for double-electron emission of {sup 76}Ge to be 2039.061(7) keV. The new Q{sub 2EC} value for {sup 74}Se precludes a large resonant enhancement for neutrinoless double-electron capture.

  10. Neutrino oscillation constraints on neutrinoless double-beta decay

    NASA Astrophysics Data System (ADS)

    Bilenky, S. M.; Giunti, C.; Kim, C. W.; Monteno, M.

    1998-06-01

    We have studied the constraints imposed by the results of neutrino oscillation experiments on the effective Majorana mass \\|\\| that characterizes the contribution of Majorana neutrino masses to the matrix element of neutrinoless double-beta decay. We have shown that in a general scheme with three Majorana neutrinos and a hierarchy of neutrino masses (which corresponds to the standard seesaw mechanism) the results of neutrino oscillation experiments imply rather strong constraints on the parameter \\|\\|. From the results of the first reactor long-baseline experiment CHOOZ and the Bugey experiment it follows that \\|\\|<~3×10-2 eV if Δm2<~2 eV2 (Δm2 is the largest mass-squared difference). Hence, we conclude that the observation of neutrinoless double-beta decay with a probability that corresponds to \\|\\|>~10-1 eV would be a signal for a nonhierarchical neutrino mass spectrum and/or nonstandard mechanisms of lepton number violation.

  11. NuDot: Search for neutrinoless double-beta decay

    NASA Astrophysics Data System (ADS)

    Santana, Jesse

    2015-10-01

    NuDot is a prototype, liquid scintillator detector, to demonstrate that the separation of directional Cherenkov light from isotropic scintillation light is possible using sub-nanosecond photodetectors. NuDot is currently being tested on a small scale before ramping up to a one-metric ton prototype in the next three years. A proof-of-concept setup for separating the light as well as calibrating the PMTs' timing has been designed. The setup consist of two LEDs, the first of which will mimic the cherenkov light while the second represents the scintillating light. NuDot's main application is the search for neutrinoless double beta decay, but it could also be used to reduce backgrounds in studies of geo-neutrinos, solar neutrinos, supernovae neutrinos and neutrino interactions. By being sensitive to the Cherenkov light a detector will have directionality for events and increase it's energy resolution- these two effects can provide methods to veto backgrounds- which then allow for a better analysis of rare phenomena such as neutrinoless double beta decay.

  12. The MAJORANA DEMONSTRATOR: A search for neutrinoless double-beta decay of germanium-76

    NASA Astrophysics Data System (ADS)

    Schubert, Alexis; Majorana Collaboration

    2011-04-01

    Observation of neutrinoless double-beta decay (0 νββ) could determine whether the neutrino is a Majorana particle and may provide information on neutrino mass. The MAJORANA Collaboration will search for 0 νββ of 76Ge in an array of germanium detectors enriched to 86% in 76Ge. Germanium detectors are a well-understood technology and have the benefits of excellent energy resolution, a high Q-value, and the ability to act as source and detector. The p-type point contact germanium detectors chosen by the MAJORANA Collaboration provide low noise, low energy threshold, and some ability to distinguish between the signal and background events. MAJORANA is constructing the DEMONSTRATOR, which will be used to conduct research and development toward a tonne-scale Ge experiment. The DEMONSTRATOR will be installed deep underground and will contain 40 kg of Ge deployed in an ultra-low-background shielded environment. Research supported by DOE under contracts DE-AC05-00OR22725 and DE-FG02-97ER41020.

  13. Early results from the Battelle-Carolina /sup 76/Ge double-beta-decay project

    SciTech Connect

    Brodzinski, R.L.; Avignone, F.T.; Brown, D.P.; Evans, J.C.; Hensley, W.K.; Reeves, J.H.; Wogman, N.A.

    1982-10-01

    A search for no-neutrino double beta decay of /sup 76/Ge using an anticoincidence shielded Ge spectrometer is reported. A new lower limit of T/sub 1/2/ greater than or equal to 1.7 x 10/sup 22/ y at a 90% CL was determined using a maximum likelihood analysis on a 5 keV wide energy bin centered at 2041 keV. Combining this result with the shell model calculations of Haxton, Stephenson and Strottman, we obtain average m/sub nu/ less than or equal to 10 eV and parallel eta parallel less than or equal to 2.4 x 10/sup -5/.

  14. Early results from the Battelle-Carolina /sup 76/Ge double beta decay project

    SciTech Connect

    Avignone, F.T. III; Brodzinski, R.L.; Brown, D.P.; Evans, J.C. Jr.; Hensley, W.K.; Reeves, J.H.; Wogman, N.A.

    1983-01-01

    A search for no-neutrino double beta decay of /sup 76/Ge using an anticoincidence shielded Ge spectrometer is reported. A new lower limit of T/sub 1/2/ greater than or equal to 1.7 x 10/sup 22/ y at a 90% CL was determined using a maximum likelihood analysis on a 5 keV wide energy bin centered at 2041 keV. Combining this result with the shell model calculations of Haxton, Stephenson and Strottman, we obtain anti m/sub nu/ less than or equal to 10 eV and absolute value eta less than or equal to 2.4 x 10/sup -5/.

  15. Development of Micromegas for neutrinoless double beta decay searches

    NASA Astrophysics Data System (ADS)

    Tomás, A.; Carmona, J. M.; Cebrián, S.; Dafni, T.; Ferrer-Ribas, E.; Galán, J.; Giomataris, I.; Gómez, H.; Gorodetzky, P.; Iguaz, F. J.; Irastorza, I. G.; Jeanneau, F.; Luzón, G.; Morales, J.; Papaevangelou, T.; Rodríguez, A.; Ruz, J.; Salin, P.; Seguí, L.; Villar, J. A.

    2009-11-01

    The present paper is a summary of experimental tests performed with microbulk Micromegas for application in a neutrinoless double beta decay experiment based in a xenon TPC. No critical limitation related with high pressure has been detected for Micromegas, which has been tested up to 10 bar. No significant differences have been found between low energy X-rays and high energy alpha tracks regarding ionization yield and electronic transparency of Micromegas mesh. Using 5.5 MeV alphas in argon-isobutane mixtures, values as low as 1.8% FWHM have been obtained, with possible evidence that better resolutions are achievable. These results seems independent of pressure (probed up to 4.5 bar) or gas mixture (microbulks have run in xenon without quencher). The imperative necessity of high quality gas led to start on a new TPC and MPGD dedicated lab at Zaragoza.

  16. The MAJORANA DEMONSTRATOR Neutrinoless Double-Beta Decay Experiment

    SciTech Connect

    Abgrall, N.; Aguayo, Estanislao; Avignone, Frank T.; Barabash, Alexander S.; Bertrand, F.; Boswell, M.; Brudanin, V.; Busch, Matthew; Caldwell, A. S.; Chan, Yuen-Dat; Christofferson, Cabot-Ann; Combs, Dustin C.; Detwiler, Jason A.; Doe, Peter J.; Efremenko, Yuri; Egorov, Viatcheslav; Ejiri, H.; Elliott, S. R.; Esterline, James H.; Fast, James E.; Finnerty, P.; Fraenkle, Florian; Galindo-Uribarri, A.; Giovanetti, G. K.; Goett, J.; Green, M.; Gruszko, J.; Guiseppe, Vincente; Gusev, K.; Hallin, A. L.; Hazama, R.; Hegai, A.; Henning, Reyco; Hoppe, Eric W.; Howard, Stanley; Howe, M. A.; Keeter, K.; Kidd, M. F.; Knecht, A.; Kochetov, Oleg; Konovalov, S.; Kouzes, Richard T.; Laferriere, Brian D.; Leon, Jonathan D.; Leviner, L.; Loach, J. C.; Luke, P.; MacMullin, S.; Martin, R. D.; Mertens, S.; Mizouni, Leila; Nomachi, Masaharu; Orrell, John L.; O'Shaughnessy, C.; Overman, Nicole R.; Phillips, David; Poon, Alan; Pushkin, K.; Radford, D. C.; Rielage, Keith; Robertson, R. G. H.; Ronquest, M. C.; Schubert, Alexis G.; Shanks, B.; Shima, T.; Shirchenko, M.; Snavely, Kyle J.; Snyder, N.; Steele, David; Strain, J.; Suriano, Anne-Marie; Thompson, J.; Timkin, V.; Tornow, Werner; Varner, R. L.; Vasilyev, Sergey; Vetter, Kai; Vorren, Kris R.; White, Brandon R.; Wilkerson, J. F.; Williams, T.; Xu, W.; Yakushev, E.; Young, A.; Yu, Chang-Hong; Yumatov, Vladimir

    2014-06-01

    The MAJORANA DEMONSTRATOR will search for the neutrinoless double-beta (ββ(0ν)) decay of the isotope 76Ge with a mixed array of enriched and natural germanium detectors. The observation of this rare decay would indicate that the neutrino is its own antiparticle, demonstrate that lepton number is not conserved, and provide information on the absolute mass scale of the neutrino. The DEMONSTRATOR is being assembled at the 4850-foot level of the Sanford Underground Research Facility in Lead, South Dakota. The array will be situated in a low-background environment and surrounded by passive and active shielding. Here we describe the science goals of the DEMONSTRATOR and the details of its design.

  17. The MAJORANA DEMONSTRATOR Neutrinoless Double-Beta Decay Experiment

    SciTech Connect

    Abgrall, N.; Aguayo, Estanislao; Avignone, III, F. T.; Barabash, A.; Bertrand, F.; Boswell, M.; Brudanin, V.; Busch, Matthew; Caldwell, A. S.; Chan, Yuen-Dat; Christofferson, Cabot-Ann; Combs, Dustin C.; Detwiler, Jason A.; Doe, Peter J.; Efremenko, Yuri; Egorov, Viatcheslav; Ejiri, H.; Elliott, S. R.; Esterline, James H.; Fast, James E.; Finnerty, P.; Fraenkle, Florian; Galindo-Uribarri, A.; Giovanetti, G. K.; Goett, J.; Green, M.; Gruszko, J.; Guiseppe, Vincente; Gusev, K.; Hallin, A. L.; Hazama, R.; Hegai, A.; Henning, Reyco; Hoppe, Eric W.; Howard, Stanley; Howe, M. A.; Keeter, K.; Kidd, M. F.; Knecht, A.; Kochetov, Oleg; Konovalov, S.; Kouzes, Richard T.; Laferriere, Brian D.; Leon, Jonathan D.; Leviner, L.; Loach, J. C.; Luke, P.; MacMullin, S.; Martin, R. D.; Mertens, S.; Mizouni, Leila; Nomachi, Masaharu; Orrell, John L.; O'Shaughnessy, Mark D.; Overman, Nicole R.; Phillips, David; Poon, Alan; Pushkin, K.; Radford, D. C.; Rielage, Keith; Robertson, R. G. H.; Ronquest, M. C.; Schubert, Alexis G.; Shanks, B.; Shima, T.; Shirchenko, M.; Snavely, Kyle J.; Snyder, N.; Steele, David; Strain, J.; Suriano, Anne-Marie; Thompson, J.; Timkin, V.; Tornow, Werner; Varner, R. L.; Vasilyev, Sergey; Vetter, Kai; Vorren, Kris R.; White, Brandon R.; Wilkerson, J. F.; Williams, T.; Xu, W.; Yakushev, E.; Young, A.; Yu, Chang-Hong; Yumatov, Vladimir

    2014-01-01

    The Majorana Demonstrator will search for the neutrinoless double-beta (ββ (0ν)) decay of the isotope 76Ge with a mixed array of enriched and natural germanium detectors. The observation of this rare decay would indicate that the neutrino is its own antiparticle, demonstrate that lepton number is not conserved, and provide information on the absolute mass scale of the neutrino. TheDemonstrator is being assembled at the 4850-foot level of the SanfordUnderground Research Facility in Lead, SouthDakota. The array will be situated in a low-background environment and surrounded by passive and active shielding. Here we describe the science goals of the Demonstrator and the details of its design.

  18. The MAJORANA DEMONSTRATOR Neutrinoless Double-Beta Decay Experiment

    DOE PAGES

    Abgrall, N.; Aguayo, E.; Avignone, F. T.; ...

    2014-01-01

    Tmore » he M ajorana D emonstrator will search for the neutrinoless double-beta ( β β 0 ν ) decay of the isotope Ge with a mixed array of enriched and natural germanium detectors.he observation of this rare decay would indicate that the neutrino is its own antiparticle, demonstrate that lepton number is not conserved, and provide information on the absolute mass scale of the neutrino.he D emonstrator is being assembled at the 4850-foot level of the Sanford Underground Research Facility in Lead, South Dakota.he array will be situated in a low-background environment and surrounded by passive and active shielding. Here we describe the science goals of the D emonstrator and the details of its design. « less

  19. First neutrinoless double beta decay results from CUORE-0

    SciTech Connect

    Gironi, L. Biassoni, M.; Brofferio, C.; Capelli, S.; Carniti, P.; Cassina, L.; Chiesa, D.; Clemenza, M.; Faverzani, M.; Ferri, E.; Gotti, C.; Maino, M.; Nucciotti, A.; Pavan, M.; Pozzi, S.; Sala, E.; Sisti, M.; Terranova, F.; Zanotti, L.; Alduino, C.; and others

    2015-10-28

    The CUORE-0 experiment, a 52 bolometer array searching for neutrinoless double beta decay from {sup 130}Te, has started taking data in spring 2013 underground at the Laboratori Nazionali del Gran Sasso (LNGS). The excellent results obtained in terms of energy resolution and background level allowed this experiment to reach the sensitivity of Cuoricino in approximately half the runtime. Combining CUORE-0 data (9.8 kg·yr exposure of {sup 130}Te) with the 19.75 kg·yr exposure of the Cuoricino experiment, we obtain the most stringent limit to date on the half-life of this isotope (T{sub 1/2} > 4.0 × 10{sup 24} yr). In this article, we review the results from CUORE-0 and discuss the status and the physics potential of CUORE, a 19 times larger bolometer array that plans to begin operations by end of this year.

  20. The Nuclear and Particle Physics of Neutrinoless Double Beta Decay

    NASA Astrophysics Data System (ADS)

    Haxton, Wick

    2014-03-01

    Fortuitous properties of nuclei allow us to isolate and study the rare second-order weak process of double beta decay. In particular, the decay channel in which a final state of two electrons and no neutrinos is produced - neutrinoless double beta decay - provides our best test of lepton number conservation and the Majorana mass of the electron neutrino. I will describe the connections between this process and the charge conjugation properties of the neutrino, including the possibility that the presence of both Dirac and Majorana masses accounts for the anomalous scale of neutrino masses. The extraordinary progress made over the past two decades has prepared the way for next-generation experiments that will probe Majorana masses at levels where nonzero rates may be found, given what we now know about neutrino mass splittings. I will describe some of the heroic efforts underway to develop detectors of unprecedented size, radiopurity, depth, and thus sensitivity. Work supported by the Office of Science, US DOE.

  1. The neutrinoless double beta decay from a modern perspective

    NASA Astrophysics Data System (ADS)

    Vergados, J. D.

    2002-04-01

    Neutrinoless double beta decay is a very important process both from the particle and nuclear physics point of view. From the elementary particle point of view it pops up in almost every model, giving rise, among others, to the following mechanisms: (a) The traditional contributions like the light neutrino mass mechanism as well as the jL- jR leptonic interference ( λ and η terms). (b) The exotic R-parity violating supersymmetric (SUSY) contributions. In this scheme, the currents are only left handed and the intermediate particles normally are very heavy. There exists, however, the possibility of light intermediate neutrinos arising from the combination of V-A and P-S currents at the quark level. This leads to the same structure as the above λ term. Similar considerations apply to its sister lepton and muon number violating muon to positron conversion in the presence of nuclei. Anyway, regardless of the dominant mechanism, the observation of neutrinoless double betas decay, which is the most important of the two from an experimental point of view, will severely constrain the existing models and will signal that the neutrinos are massive Majorana particles. From the nuclear physics point of view it is challenging, because: (1) The nuclei, which can undergo double beta decay, have a complicated nuclear structure. (2) The energetically allowed transitions are suppressed (exhaust a small part of the entire strength). (3) Since in some mechanisms the intermediate particles are very heavy, one must cope with the short distance behavior of the transition operators. Thus novel effects, like the double beta decay of pions in flight between nucleons, have to be considered. In SUSY models this mechanism is more important than the standard two nucleon mechanism. (4) The intermediate momenta involved are quite high (about 100 MeV/c ). Thus, one has to take into account possible momentum-dependent terms of the nucleon current, like the modification of the axial current due to

  2. Internal Energy Loss of the Electrons Ejected in Neutrinoless Double Beta Decay

    NASA Astrophysics Data System (ADS)

    Drukarev, E. G.; Amusia, M. Ya.; Chernysheva, L. V.

    2017-01-01

    The excitations of the electron shell in neutrinoless double beta decay shifts the limiting energy available for ejected electrons. We present the general equations for this shift and make computations for the decays of two nuclei—germanium and xenon.

  3. The Majorana Demonstrator Neutrinoless Double Beta Decay Experiment

    NASA Astrophysics Data System (ADS)

    Massarczyk, Ralph; Majorana Collaboration

    2016-03-01

    Neutrinoless double beta decay searches play a major role in determining neutrino properties. The Majorana Collaboration is constructing an ultra-low background, modular high-purity Ge detector array to search for this decay in 76Ge. Located at the 4850-ft level of the Sanford Underground Research Facility, the Demonstrator detector assembly has the goal to show that it is possible to achieve background rates necessary for future ton-scale experiments. The talk will give a short introduction to the experiment, an overview of the achievements made in detector construction, data analysis and simulation. After the first commissioning phase last year with more than half of the detectors in their final configuration, the current status of the Demonstrator will be presented in this talk as well as plans for the future. This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics, the Particle Astrophysics Program of the National Science Foundation, and the Sanford Underground Research Facility. We acknowledge the support of the U.S. Department of Energy through the LANL/LDRD Program.

  4. The MGDO software library for data analysis in Ge neutrinoless double-beta decay experiments

    NASA Astrophysics Data System (ADS)

    Agostini, M.; Detwiler, J. A.; Finnerty, P.; Kröninger, K.; Lenz, D.; Liu, J.; Marino, M. G.; Martin, R.; Nguyen, K. D.; Pandola, L.; Schubert, A. G.; Volynets, O.; Zavarise, P.

    2012-07-01

    The Gerda and Majorana experiments will search for neutrinoless double-beta decay of 76Ge using isotopically enriched high-purity germanium detectors. Although the experiments differ in conceptual design, they share many aspects in common, and in particular will employ similar data analysis techniques. The collaborations are jointly developing a C++ software library, MGDO, which contains a set of data objects and interfaces to encapsulate, store and manage physical quantities of interest, such as waveforms and high-purity germanium detector geometries. These data objects define a common format for persistent data, whether it is generated by Monte Carlo simulations or an experimental apparatus, to reduce code duplication and to ease the exchange of information between detector systems. MGDO also includes general-purpose analysis tools that can be used for the processing of measured or simulated digital signals. The MGDO design is based on the Object-Oriented programming paradigm and is very flexible, allowing for easy extension and customization of the components. The tools provided by the MGDO libraries are used by both Gerda and Majorana.

  5. LUCIFER: scintillating bolometers for neutrinoless double-beta decay searches

    NASA Astrophysics Data System (ADS)

    Pattavina, Luca

    2014-09-01

    In the field of fundamental particle physics, the nature of the neutrino, if it is a Dirac or a Majorana particle, plays a crucial role not only in neutrino physics, but also in the overall framework of fundamental particle interactions and in cosmology. Neutrinoless double-beta decay (0vDBD) is the key tool for the investigation of this nature. Experimental techniques based on the calorimetric approach with cryogenic particle detectors have demonstrated suitability for the investigation of rare nuclear processes, profiting from excellent energy resolution and scalability to large masses. Unfortunately, the most relevant issue is related to background suppression. In fact, bolometers being fully-active detectors struggle to reach extremely low background level. The LUCIFER project aims to deploy the first array of enriched scintillating bolometers. Thanks to the double read-out - heat and scintillation light produced by scintillating bolometers - a highly efficient background identification and rejection is guaranteed, leading to a background-free experiment. We show the potential of such technology in ZnMoO4 and ZnSe prototypes. We describe the current status of the project, including results of the recent R&D activity.

  6. Sensitivity of NEXT-100 to neutrinoless double beta decay

    NASA Astrophysics Data System (ADS)

    Martín-Albo, J.; Muñoz Vidal, J.; Ferrario, P.; Nebot-Guinot, M.; Gómez-Cadenas, J. J.; Álvarez, V.; Azevedo, C. D. R.; Borges, F. I. G.; Cárcel, S.; Carrión, J. V.; Cebrián, S.; Cervera, A.; Conde, C. A. N.; Díaz, J.; Diesburg, M.; Esteve, R.; Fernandes, L. M. P.; Ferreira, A. L.; Freitas, E. D. C.; Goldschmidt, A.; González-Díaz, D.; Gutiérrez, R. M.; Hauptman, J.; Henriques, C. A. O.; Hernando Morata, J. A.; Herrero, V.; Labarga, L.; Laing, A.; Lebrun, P.; Liubarsky, I.; López-March, N.; Lorca, D.; Losada, M.; Martínez-Lema, G.; Martínez, A.; Monrabal, F.; Monteiro, C. M. B.; Mora, F. J.; Moutinho, L. M.; Novella, P.; Nygren, D.; Palmeiro, B.; Para, A.; Querol, M.; Renner, J.; Ripoll, L.; Rodríguez, J.; Santos, F. P.; dos Santos, J. M. F.; Serra, L.; Shuman, D.; Simón, A.; Sofka, C.; Sorel, M.; Stiegler, T.; Toledo, J. F.; Torrent, J.; Tsamalaidze, Z.; Veloso, J. F. C. A.; Webb, R.; White, J. T.; Yahlali, N.; Yepes-Ramírez, H.

    2016-05-01

    NEXT-100 is an electroluminescent high-pressure xenon gas time projection chamber that will search for the neutrinoless double beta (0 νββ) decay of 136Xe. The detector possesses two features of great value for 0 νββ searches: energy resolution better than 1% FWHM at the Q value of 136Xe and track reconstruction for the discrimination of signal and background events. This combination results in excellent sensitivity, as discussed in this paper. Material-screening measurements and a detailed Monte Carlo detector simulation predict a background rate for NEXT-100 of at most 4 × 10-4 counts keV-1 kg-1 yr-1. Accordingly, the detector will reach a sensitivity to the 0 νββ-decay half-life of 2.8 × 1025 years (90% CL) for an exposure of 100 kg·year, or 6.0 × 1025 years after a run of 3 effective years. [Figure not available: see fulltext.

  7. Neutrinoless Double Beta Decay from a Modern Perspective

    NASA Astrophysics Data System (ADS)

    Vergados, J. D.

    2002-04-01

    Neutrinoless double beta decay is important both from the particle and nuclear physics point of view. From the elementary particle point of view it pops up everywhere , giving rise to the following: The light and heavy neutrino average mass, the right handed λ and η couplings, the SUSY R-parity breaking lepton violating parameter as well as that arising from physics in extra dimensions (branes) etc. Regardless of the dominant mechanism its observation will signal that the neutrinos are massive Majorana particles. From the nuclear physics point of view it is challenging because: 1) The relevant nuclei have complicated nuclear structure. 2) The energetically allowed transitions are suppressed . 3) The intermediate particles in some mechanisms are so heavy that the short distance behavior must be tackled. 4) The momentum dependent terms of the nucleon current cannot be ignored. Taking such effects into account the nuclear matrix elements for A = 76, 82, 96, 100, 116, 128, 130, 136 and 150 have become reliable. From the presently available experimental limits on the half-lives, new limits on the relevant lepton violating parameters have been extracted imposing stringent constraints on the fashionable particle models.

  8. Neutrinoless double beta decay in the left-right symmetric models for linear seesaw

    NASA Astrophysics Data System (ADS)

    Gu, Pei-Hong

    2016-09-01

    In a class of left-right symmetric models for linear seesaw, a neutrinoless double beta decay induced by the left- and right-handed charged currents together will only depend on the breaking details of left-right and electroweak symmetries. This neutrinoless double beta decay can reach the experimental sensitivities if the right-handed charged gauge boson is below the 100TeV scale.

  9. Occupancies of individual orbits, and the nuclear matrix element of the {sup 76}Ge neutrinoless {beta}{beta} decay

    SciTech Connect

    Menendez, J.; Poves, A.

    2009-10-15

    We discuss the variation of the nuclear matrix element (NME) for the neutrinoless double beta (0{nu}{beta}{beta}) decay of {sup 76}Ge when the wave functions are constrained to reproduce the experimental occupancies of the two nuclei involved in the transition. In the interacting shell model description the value of the NME is enhanced about 15% compared to previous calculations, whereas in the QRPA the NME's are reduced by 20%-30%. This diminishes the discrepancies between both approaches. In addition, we discuss the effect of the short-range correlations on the NME in light of the recently proposed parametrizations based on a consistent renormalization of the 0{nu}{beta}{beta} transition operator.

  10. The MAJORANA DEMONSTRATOR: An R&D project towards a tonne-scale germanium neutrinoless double-beta decay search

    SciTech Connect

    Aalseth, Craig E; Amman, M; Amsbaugh, John F; Avignone, F. T.; Back, Henning O; Barabash, A; Barbeau, Phil; Beene, Jim; Bergevin, M; Bertrand, F; Boswell, M; Brudanin, V; Bugg, William; Burritt, Tom H; Chan, Yuen-Dat; Collar, J I; Cooper, R J; Creswick, R; Detwiler, Jason A; Doe, P J; Efremenko, Yuri; Egorov, Viatcheslav; Ejiri, H; Elliott, Steven R; Ely, James H; Esterline, James H; Farach, H A; Fast, James E; Fields, N; Finnerty, P; Fujikawa, Brian; Fuller, Erin S; Gehman, Victor; Giovanetti, G K; Guiseppe, Vincente; Gusey, K; Hallin, A L; Hazama, R; Henning, Reyco; Hime, Andrew; Hoppe, Eric W; Hossbach, Todd W; Howe, M A; Johnson, R A; Keeter, K; Keillor, Martin E; Keller, C; Kephart, Jeremy D; Kidd, Mary; Kochetov, Oleg; Konovalov, S; Kouzes, Richard T; Lesko, Kevin; Leviner, L; Loach, J C; Luke, P; MacMullin, S; Marino, Michael G; Mei, Dong-Ming; Miley, Harry S; Miller, M; Mizouni, Leila K; Montoya, A; Myers, A W; Nomachi, Masaharu; Odom, Brian; Orrell, John L; Phillips, D; Poon, Alan; Prior, Gersende; Qian, J; Radford, D C; Rielage, Keith; Robertson, R G. H.; Rodriguez, Larry; Rykaczewski, Krzysztof P; Schubert, Alexis G; Shima, T; Shirchenko, M; Strain, J; Thomas, K; Thompson, Robert C; Timkin, V; Tornow, W; Van Wechel, T D; Vanyushin, I; Vetter, Kai; Warner, Ray A; Wilkerson, J; Wouters, Jan; Yakushev, E; Young, A; Yu, Chang-Hong; Yumatov, Vladimir; Zhang, C L; Zimmerman, S

    2009-12-17

    The MAJORANA collaboration is pursuing the development of the so-called MAJORANA DEMONSTRATOR. The DEMONSTRATOR is intended to perform research and development towards a tonne-scale germanium-based experiment to search for the neutrinoless double-beta decay of 76Ge. The DEMONSTRATOR can also perform a competitive direct dark matter search for light WIMPs in the 1-10GeV/c2 mass range. It will consist of approximately 60 kg. of germanium detectors in an ultra-low background shield located deep underground at the Sanford Underground Laboratory in Lead, SD. The DEMONSTRATOR will also perform background and technology studies, and half of the detector mass will be enriched germanium. This talk will review the motivation, design, technology and status of the Demonstrator.

  11. The MAJORANA DEMONSTRATOR: An R and D project towards a tonne-scale germanium neutrinoless double-beta decay search

    SciTech Connect

    Aalseth, C. E.; Ely, J.; Fast, J. E.; Fuller, E.; Hoppe, E. W.; Keillor, M.; Kouzes, R. T.; Miley, H. S.; Orrell, J. L.; Thompson, R.; Warner, R.; Amman, M.; Bergevin, M.; Chan, Y.-D.; Detwiler, J. A.; Fujikawa, B.; Loach, J. C.; Luke, P. N.; Poon, A. W. P; Prior, G.

    2009-12-17

    The MAJORANA collaboration is pursuing the development of the so-called MAJORANA DEMONSTRATOR. The DEMONSTRATOR is intended to perform research and development towards a tonne-scale germanium-based experiment to search for the neutrinoless double-beta decay of {sup 76}Ge. The DEMONSTRATOR can also perform a competitive direct dark matter search for light WIMPs in the 1-10 GeV/c{sup 2} mass range. It will consist of approximately 60 kg of germanium detectors in an ultra-low background shield located deep underground at the Sanford Underground Laboratory in Lead, SD. The DEMONSTRATOR will also perform background and technology studies, and half of the detector mass will be enriched germanium. This talk will review the motivation, design, technology and status of the Demonstrator.

  12. Neutron Interactions in the CUORE Neutrinoless Double Beta Decay Experiment

    SciTech Connect

    Dolinski, Michelle Jean

    2008-10-01

    Neutrinoless double beta decay (0vDBD) is a lepton-number violating process that can occur only for a massive Majorana neutrino. The search for 0vDBD is currently the only practical experimental way to determine whether neutrinos are identical to their own antiparticles (Majorana neutrinos) or have distinct particle and anti-particle states (Dirac neutrinos). In addition, the observation of 0vDBD can provide information about the absolute mass scale of the neutrino. The Cuoricino experiment was a sensitive search for 0vDBD, as well as a proof of principle for the next generation experiment, CUORE. CUORE will search for 0vDBD of 130Te with a ton-scale array of unenriched TeO2 bolometers. By increasing mass and decreasing the background for 0vDBD, the half-life sensitivity of CUORE will be a factor of twenty better than that of Cuoricino. The site for both of these experiments is the Laboratori Nazionali del Gran Sasso, an underground laboratory with 3300 meters water equivalent rock overburden and a cosmic ray muon attenuation factor of 10-6. Because of the extreme low background requirements for CUORE, it is important that all potential sources of background in the 0vDBD peak region at 2530 keV are well understood. One potential source of background for CUORE comes from neutrons, which can be produced underground both by (α,n) reactions and by fast cosmic ray muon interactions. Preliminary simulations by the CUORE collaboration indicate that these backgrounds will be negligible for CUORE. However, in order to accurately simulate the expected neutron background, it is important to understand the cross sections for neutron interactions with detector materials. In order to help refine these simulations, I have measured the gamma-ray production cross sections for interactions of neutrons on the abundant stable isotopes of Te using the GEANIE detector array at the Los Alamos Neutron Science Center. In addition, I have used the GEANIE

  13. Neutrinoless Double Beta Nuclear Matrix Elements Around Mass 80 in the Nuclear Shell Model

    NASA Astrophysics Data System (ADS)

    Yoshinaga, Naotaka; Higashiyama, Koji; Taguchi, Daisuke; Teruya, Eri

    The observation of the neutrinoless double-beta decay can determine whether the neutrino is a Majorana particle or not. In its theoretical nuclear side it is particularly important to estimate three types of nuclear matrix elements, namely, Fermi (F), Gamow-Teller (GT), and tensor (T) types matrix elements. The shell model calculations and also the pair-truncated shell model calculations are carried out to check the model dependence on nuclear matrix elements. In this work the neutrinoless double-beta decay for mass A = 82 nuclei is studied. It is found that the matrix elements are quite sensitive to the ground state wavefunctions.

  14. Nuclear structure relevant to neutrinoless double beta decay candidate {sup 130}Te and other recent results

    SciTech Connect

    Kay, B. P.

    2013-12-30

    We have undertaken a series of single-nucleon and pair transfer reaction measurements to help constrain calculations of the nuclear matrix elements for neutrinoless double beta decay. In this talk, a short overview of measurements relevant to the {sup 130}Te→{sup 130}Xe system is given. Brief mention is made of other recent and forthcoming results.

  15. New limits on the neutrino mass, lepton conservation, and no-neutrino double beta decay of /sup 76/Ge

    SciTech Connect

    Avignone, F.T. III; Brodzinski, R.L.; Brown, D.P.; Evans, J.C. Jr.; Hensley, W.K.; Reeves, J.H.; Wogman, N.A.

    1983-03-07

    A continuing search for the no-neutrino mode of the double beta decay of /sup 76/Ge has resulted in a new lower limit T/sub 1/2//sup 0nu/ > or =1.7 x 10/sup 22/ yr. This value corresponds to a 90% confidence level determined with a maximum-likelihood analysis of the energy interval 2041 +- 2 keV. Combined with recent shell-model calculations, the data imply m/sub ..nu../< or =10 eV and a limit on lepton nonconservation Vertical BaretaVertical Bar< or =2.4 x 10/sup -5/. In the context of the shell model, the data imply that the electron neutrino is not a Majorana mass eigenstate.

  16. Neutrinoless Double Beta Decay in Light of SNO Salt Data

    SciTech Connect

    Murayama, Hitoshi; Pena-Garay, Carlos

    2003-09-11

    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_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.

  17. Search for Neutrinoless Double-Beta Decay in Xe136 with EXO-200

    NASA Astrophysics Data System (ADS)

    Auger, M.; Auty, D. J.; Barbeau, P. S.; Beauchamp, E.; Belov, V.; Benitez-Medina, C.; Breidenbach, M.; Brunner, T.; Burenkov, A.; Cleveland, B.; Cook, S.; Daniels, T.; Danilov, M.; Davis, C. G.; Delaquis, S.; deVoe, R.; Dobi, A.; Dolinski, M. J.; Dolgolenko, A.; Dunford, M.; Fairbank, W., Jr.; Farine, J.; Feldmeier, W.; Fierlinger, P.; Franco, D.; Giroux, G.; Gornea, R.; Graham, K.; Gratta, G.; Hall, C.; Hall, K.; Hargrove, C.; Herrin, S.; Hughes, M.; Johnson, A.; Johnson, T. N.; Karelin, A.; Kaufman, L. J.; Kuchenkov, A.; Kumar, K. S.; Leonard, D. S.; Leonard, F.; Mackay, D.; MacLellan, R.; Marino, M.; Mong, B.; Montero Díez, M.; Müller, A. R.; Neilson, R.; Nelson, R.; Odian, A.; Ostrovskiy, I.; O'Sullivan, K.; Ouellet, C.; Piepke, A.; Pocar, A.; Prescott, C. Y.; Pushkin, K.; Rowson, P. C.; Russell, J. J.; Sabourov, A.; Sinclair, D.; Slutsky, S.; Stekhanov, V.; Tolba, T.; Tosi, D.; Twelker, K.; Vogel, P.; Vuilleumier, J.-L.; Waite, A.; Walton, T.; Weber, M.; Wichoski, U.; Wodin, J.; Wright, J. D.; Yang, L.; Yen, Y.-R.; Zeldovich, O. Ya.

    2012-07-01

    We report on a search for neutrinoless double-beta decay of Xe136 with EXO-200. No signal is observed for an exposure of 32.5 kg yr, with a background of ˜1.5×10-3kg-1yr-1keV-1 in the ±1σ region of interest. This sets a lower limit on the half-life of the neutrinoless double-beta decay T1/20νββ(Xe136)>1.6×1025yr (90% C.L.), corresponding to effective Majorana masses of less than 140-380 meV, depending on the matrix element calculation.

  18. Search for neutrinoless double-beta decay in 136Xe with EXO-200.

    PubMed

    Auger, M; Auty, D J; Barbeau, P S; Beauchamp, E; Belov, V; Benitez-Medina, C; Breidenbach, M; Brunner, T; Burenkov, A; Cleveland, B; Cook, S; Daniels, T; Danilov, M; Davis, C G; Delaquis, S; deVoe, R; Dobi, A; Dolinski, M J; Dolgolenko, A; Dunford, M; Fairbank, W; Farine, J; Feldmeier, W; Fierlinger, P; Franco, D; Giroux, G; Gornea, R; Graham, K; Gratta, G; Hall, C; Hall, K; Hargrove, C; Herrin, S; Hughes, M; Johnson, A; Johnson, T N; Karelin, A; Kaufman, L J; Kuchenkov, A; Kumar, K S; Leonard, D S; Leonard, F; Mackay, D; MacLellan, R; Marino, M; Mong, B; Montero Díez, M; Müller, A R; Neilson, R; Nelson, R; Odian, A; Ostrovskiy, I; O'Sullivan, K; Ouellet, C; Piepke, A; Pocar, A; Prescott, C Y; Pushkin, K; Rowson, P C; Russell, J J; Sabourov, A; Sinclair, D; Slutsky, S; Stekhanov, V; Tolba, T; Tosi, D; Twelker, K; Vogel, P; Vuilleumier, J-L; Waite, A; Walton, T; Weber, M; Wichoski, U; Wodin, J; Wright, J D; Yang, L; Yen, Y-R; Zeldovich, O Ya

    2012-07-20

    We report on a search for neutrinoless double-beta decay of 136Xe with EXO-200. No signal is observed for an exposure of 32.5 kg yr, with a background of ∼1.5×10(-3)  kg(-1) yr(-1)  keV(-1) in the ±1σ region of interest. This sets a lower limit on the half-life of the neutrinoless double-beta decay T(1/2)(0νββ)(136Xe)>1.6×10(25)  yr (90% C.L.), corresponding to effective Majorana masses of less than 140-380 meV, depending on the matrix element calculation.

  19. The next generation neutrinoless double-beta decay experiment nEXO

    NASA Astrophysics Data System (ADS)

    MacLellan, Ryan; nEXO Collaboration

    2017-01-01

    The nEXO Collaboration is actively engaged in R&D towards a very large detector for neutrinoless double beta decay of 136Xe. 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 ×1025 y with an exposure of 99.8 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 initial goal for nEXO is a neutrinoless double-beta decay half-life sensitivity of 1 ×1028 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.

  20. Neutrinoless double beta nuclear matrix elements around mass 80 in the nuclear shell-model

    NASA Astrophysics Data System (ADS)

    Yoshinaga, N.; Higashiyama, K.; Taguchi, D.; Teruya, E.

    2015-05-01

    The observation of the neutrinoless double-beta decay can determine whether the neutrino is a Majorana particle or not. For theoretical nuclear physics it is particularly important to estimate three types of matrix elements, namely Fermi (F), Gamow-Teller (GT), and tensor (T) matrix elements. In this paper, we carry out shell-model calculations and also pair-truncated shell-model calculations to check the model dependence in the case of mass A=82 nuclei.

  1. Are massive Majorana neutrinos canceling each other in neutrinoless double-. beta. decay

    SciTech Connect

    Vergados, J.D.

    1983-12-01

    The possibility of various massive Majorana neutrinos canceling each other in neutrinoless double-..beta.. decay is examined. It is shown that if all neutrino eigenmasses are less than 10 MeV such a cancellation persists in the hadronic medium if initially present at the elementary (gauge) level. The same is true for neutrino mass greater than 10 GeV. In all other cases, such a cancellation will require a conspiracy between particle and nuclear physics.

  2. The MAJORANA DEMONSTRATOR: A search for neutrinoless double-beta decay of ⁷⁶Ge

    SciTech Connect

    Xu, W.; Abgrall, N.; Avignone, F. T.; Barabash, A. S.; Bertrand, F. E.; Brudanin, V.; Busch, M.; Buuck, M.; Byram, D.; Caldwell, A. S.; Chan, Y. -D.; Christofferson, C. D.; Cuesta, C.; Detwiler, J. A.; Efremenko, Yu; Ejiri, H.; Elliott, S. R.; Galindo-Uribarri, A.; Giovanetti, G. K.; Goett, J.; Green, M. P.; Gruszko, J.; Guinn, I.; Guiseppe, V. E.; Henning, R.; Hoppe, E. W.; Howard, S.; Howe, M. A.; Jasinski, B. R.; Keeter, K. J.; Kidd, M. F.; Konovalov, S. I.; Kouzes, R. T.; LaFerriere, B. D.; Leon, J.; MacMullin, J.; Martin, R. D.; Meijer, S. J.; Mertens, S.; Orrell, J. L.; O'Shaughnessy, C.; Overman, N. R.; Poon, A. W.P.; Radford, D. C.; Rager, J.; Rielage, K.; Robertson, R. G. H.; Romero-Romero, E.; Ronquest, M. C.; Shanks, B.; Shirchenko, M.; Snyder, N.; Suriano, A. M.; Tedeschi, D.; Trimble, J. E.; Varner, R. L.; Vasilyev, S.; Vetter, K.; Vorren, K.; White, B. R.; Wilkerson, J. F.; Wiseman, C.; Yakushev, E.; Yu, C. -H.; Yumatov, V.

    2015-05-01

    Neutrinoless double-beta (0νββ) decay is a hypothesized process where in some even-even nuclei it might be possible for two neutrons to simultaneously decay into two protons and two electrons without emitting neutrinos. This is possible only if neutrinos are Majorana particles, i.e. fermions that are their own antiparticles. Neutrinos being Majorana particles would explicitly violate lepton number conservation, and might play a role in the matter-antimatter asymmetry in the universe. The observation of neutrinoless double-beta decay would also provide complementary information related to neutrino masses. The Majorana Collaboration is constructing the MAJORANA DEMONSTRATOR, with a total of 40-kg Germanium detectors, to search for the 0νββ decay of ⁷⁶Ge and to demonstrate a background rate at or below 3 counts/(ROI•t•y) in the 4 keV region of interest (ROI) around the 2039 keV Q-value for ⁷⁶Ge 0νββ decay. In this paper, we discuss the physics of neutrinoless double beta decay and then focus on the MAJORANA DEMONSTRATOR, including its design and approach to achieve ultra-low backgrounds and the status of the experiment.

  3. The MAJORANA DEMONSTRATOR: A search for neutrinoless double-beta decay of ⁷⁶Ge

    DOE PAGES

    Xu, W.; Abgrall, N.; Avignone, F. T.; ...

    2015-05-01

    Neutrinoless double-beta (0νββ) decay is a hypothesized process where in some even-even nuclei it might be possible for two neutrons to simultaneously decay into two protons and two electrons without emitting neutrinos. This is possible only if neutrinos are Majorana particles, i.e. fermions that are their own antiparticles. Neutrinos being Majorana particles would explicitly violate lepton number conservation, and might play a role in the matter-antimatter asymmetry in the universe. The observation of neutrinoless double-beta decay would also provide complementary information related to neutrino masses. The Majorana Collaboration is constructing the MAJORANA DEMONSTRATOR, with a total of 40-kg Germanium detectors,more » to search for the 0νββ decay of ⁷⁶Ge and to demonstrate a background rate at or below 3 counts/(ROI•t•y) in the 4 keV region of interest (ROI) around the 2039 keV Q-value for ⁷⁶Ge 0νββ decay. In this paper, we discuss the physics of neutrinoless double beta decay and then focus on the MAJORANA DEMONSTRATOR, including its design and approach to achieve ultra-low backgrounds and the status of the experiment.« less

  4. Single molecule fluorescence imaging as a technique for barium tagging in neutrinoless double beta decay

    NASA Astrophysics Data System (ADS)

    Jones, B. J. P.; McDonald, A. D.; Nygren, D. R.

    2016-12-01

    Background rejection is key to success for future neutrinoless double beta decay experiments. To achieve sensitivity to effective Majorana lifetimes of ~ 1028 years, backgrounds must be controlled to better than 0.1 count per ton per year, beyond the reach of any present technology. In this paper we propose a new method to identify the birth of the barium daughter ion in the neutrinoless double beta decay of 136Xe. The method adapts Single Molecule Fluorescent Imaging, a technique from biochemistry research with demonstrated single ion sensitivity. We explore possible SMFI dyes suitable for the problem of barium ion detection in high pressure xenon gas, and develop a fiber-coupled sensing system with which we can detect the presence of bulk Ba++ ions remotely. We show that our sensor produces signal-to-background ratios as high as 85 in response to Ba++ ions when operated in aqueous solution. We then describe the next stage of this R&D program, which will be to demonstrate chelation and fluorescence in xenon gas. If a successful barium ion tag can be developed using SMFI adapted for high pressure xenon gas detectors, the first essentially zero background, ton-scale neutrinoless double beta decay technology could be realized.

  5. Background-free search for neutrinoless double-β decay of (76)Ge with GERDA.

    PubMed

    2017-04-05

    Many extensions of the Standard Model of particle physics explain the dominance of matter over antimatter in our Universe by neutrinos being their own antiparticles. This would imply the existence of neutrinoless double-β decay, which is an extremely rare lepton-number-violating radioactive decay process whose detection requires the utmost background suppression. Among the programmes that aim to detect this decay, the GERDA Collaboration is searching for neutrinoless double-β decay of (76)Ge by operating bare detectors, made of germanium with an enriched (76)Ge fraction, in liquid argon. After having completed Phase I of data taking, we have recently launched Phase II. Here we report that in GERDA Phase II we have achieved a background level of approximately 10(-3) counts keV(-1) kg(-1) yr(-1). This implies that the experiment is background-free, even when increasing the exposure up to design level. This is achieved by use of an active veto system, superior germanium detector energy resolution and improved background recognition of our new detectors. No signal of neutrinoless double-β decay was found when Phase I and Phase II data were combined, and we deduce a lower-limit half-life of 5.3 × 10(25) years at the 90 per cent confidence level. Our half-life sensitivity of 4.0 × 10(25) years is competitive with the best experiments that use a substantially larger isotope mass. The potential of an essentially background-free search for neutrinoless double-β decay will facilitate a larger germanium experiment with sensitivity levels that will bring us closer to clarifying whether neutrinos are their own antiparticles.

  6. Background-free search for neutrinoless double-β decay of 76Ge with GERDA

    NASA Astrophysics Data System (ADS)

    Agostini, M.; Allardt, M.; Bakalyarov, A. M.; Balata, M.; Barabanov, I.; Baudis, L.; Bauer, C.; Bellotti, E.; Belogurov, S.; Belyaev, S. T.; Benato, G.; Bettini, A.; Bezrukov, L.; Bode, T.; Borowicz, D.; Brudanin, V.; Brugnera, R.; Caldwell, A.; Cattadori, C.; Chernogorov, A.; D’Andrea, V.; Demidova, E. V.; di Marco, N.; di Vacri, A.; Domula, A.; Doroshkevich, E.; Egorov, V.; Falkenstein, R.; Fedorova, O.; Freund, K.; Frodyma, N.; Gangapshev, A.; Garfagnini, A.; Gooch, C.; Grabmayr, P.; Gurentsov, V.; Gusev, K.; Hakenmüller, J.; Hegai, A.; Heisel, M.; Hemmer, S.; Hofmann, W.; Hult, M.; Inzhechik, L. V.; Janicskó Csáthy, J.; Jochum, J.; Junker, M.; Kazalov, V.; Kihm, T.; Kirpichnikov, I. V.; Kirsch, A.; Kish, A.; Klimenko, A.; Kneißl, R.; Knöpfle, K. T.; Kochetov, O.; Kornoukhov, V. N.; Kuzminov, V. V.; Laubenstein, M.; Lazzaro, A.; Lebedev, V. I.; Lehnert, B.; Liao, H. Y.; Lindner, M.; Lippi, I.; Lubashevskiy, A.; Lubsandorzhiev, B.; Lutter, G.; Macolino, C.; Majorovits, B.; Maneschg, W.; Medinaceli, E.; Miloradovic, M.; Mingazheva, R.; Misiaszek, M.; Moseev, P.; Nemchenok, I.; Palioselitis, D.; Panas, K.; Pandola, L.; Pelczar, K.; Pullia, A.; Riboldi, S.; Rumyantseva, N.; Sada, C.; Salamida, F.; Salathe, M.; Schmitt, C.; Schneider, B.; Schönert, S.; Schreiner, J.; Schulz, O.; Schütz, A.-K.; Schwingenheuer, B.; Selivanenko, O.; Shevchik, E.; Shirchenko, M.; Simgen, H.; Smolnikov, A.; Stanco, L.; Vanhoefer, L.; Vasenko, A. A.; Veresnikova, A.; von Sturm, K.; Wagner, V.; Walter, M.; Wegmann, A.; Wester, T.; Wiesinger, C.; Wojcik, M.; Yanovich, E.; Zhitnikov, I.; Zhukov, S. V.; Zinatulina, D.; Zuber, K.; Zuzel, G.; GERDA Collaboration

    2017-04-01

    Many extensions of the Standard Model of particle physics explain the dominance of matter over antimatter in our Universe by neutrinos being their own antiparticles. This would imply the existence of neutrinoless double-β decay, which is an extremely rare lepton-number-violating radioactive decay process whose detection requires the utmost background suppression. Among the programmes that aim to detect this decay, the GERDA Collaboration is searching for neutrinoless double-β decay of 76Ge by operating bare detectors, made of germanium with an enriched 76Ge fraction, in liquid argon. After having completed Phase I of data taking, we have recently launched Phase II. Here we report that in GERDA Phase II we have achieved a background level of approximately 10‑3 counts keV‑1 kg‑1 yr‑1. This implies that the experiment is background-free, even when increasing the exposure up to design level. This is achieved by use of an active veto system, superior germanium detector energy resolution and improved background recognition of our new detectors. No signal of neutrinoless double-β decay was found when Phase I and Phase II data were combined, and we deduce a lower-limit half-life of 5.3 × 1025 years at the 90 per cent confidence level. Our half-life sensitivity of 4.0 × 1025 years is competitive with the best experiments that use a substantially larger isotope mass. The potential of an essentially background-free search for neutrinoless double-β decay will facilitate a larger germanium experiment with sensitivity levels that will bring us closer to clarifying whether neutrinos are their own antiparticles.

  7. MOON for neutrino-less double beta decays. Majorana neutrinos by spectroscopic studies of double beta decays

    NASA Astrophysics Data System (ADS)

    Ejiri, H.; Doe, P.; Elliott, S. R.; Engel, J.; Finger, M., Jr.; Finger, M.; Fushimi, K.; Gehman, V.; Greenfield, M.; Hazama, R.; Kavitov, P.; Kekelidze, V.; Nakamura, H.; Nomachi, M.; Robertson, R. G. H.; Shima, T.; Slunecka, M.; Shirkov, G.; Sissakian, A.; Titov, A.; Umehara, S.; Vaturin, V.; Voronov, V.; Wilkerson, J. F.; Will, D. I.; Yoshida, S.; Vrba, V.

    2008-08-01

    The MOON (Majorana/Mo Observatory Of Neutrinos) project aims at studies of the Majorana nature of the neutrino ( ν) and the ν-mass spectrum by spectroscopic experiments of neutrino-less double beta decays (0 νββ) with the ν-mass sensitivity of < m {/ν m }> = 100-30 meV. The solid scintillator option of the MOON detector is a super ensemble of multi-layer modules, each being composed by PL scintillator plates and position-sensitive detector planes with good overall energy resolution of σ ≈ 2% at the Q ββ ≈ 3 MeV. Thin ββ source films are interleaved between the detector planes. High localization of the two β tracks enables one to select true signals and reject BG ones. The multi-layer structure of the detector makes it realistic to build a compact ton-scale detector. MOON with detector ≠ ββ source is used for studying 0 νββ decays from 100Mo, 82Se and other ββ isotopes with large Q ββ . Real-time exclusive measurements of low energy solar neutrinos can be made by observing inverse β rays from solar- ν captures of 100Mo in delayed coincidence with the subsequent β decay of 100Tc.

  8. Status and future of nuclear matrix elements for neutrinoless double-beta decay: a review

    NASA Astrophysics Data System (ADS)

    Engel, Jonathan; Menéndez, Javier

    2017-04-01

    The nuclear matrix elements that govern the rate of neutrinoless double beta decay must be accurately calculated if experiments are to reach their full potential. Theorists have been working on the problem for a long time but have recently stepped up their efforts as ton-scale experiments have begun to look feasible. Here we review past and recent work on the matrix elements in a wide variety of nuclear models and discuss work that will be done in the near future. Ab initio nuclear-structure theory, which is developing rapidly, holds out hope of more accurate matrix elements with quantifiable error bars.

  9. Neutrinoless double-beta decay search with CUORE and CUORE-0 experiments

    SciTech Connect

    Moggi, N.; Artusa, D. R.; F. T. Avignone; Azzolini, O.; Balata, M.; Banks, T. I.; Bari, G.; Beeman, J.; Bellini, F.; Bersani, A.; Biassoni, M.; Brofferio, C.; Bucci, C.; Cai, X. Z.; Camacho, A.; Caminata, A.; Canonica, L.; Cao, X. G.; Capelli, S.; Cappelli, L.; Carbone, L.; Cardani, L.; Casali, N.; Cassina, L.; Chiesa, D.; Chott, N.; Clemenza, M.; Copello, S.; Cosmelli, C.; Cremonesi, O.; Creswick, R. J.; Cushman, J. S.; Dafinei, I.; Dally, A.; Datskov, V.; Dell’oro, S.; Deninno, M. M.; Di Domizio, S.; Di Vacri, M. L.; Drobizhev, A.; Ejzak, L.; Fang, D. Q.; Farach, H. A.; Faverzani, M.; Fernandes, G.; Ferri, E.; Ferroni, F.; Fiorini, E.; Franceschi, M. A.; Freedman, S. J.; Fujikawa, B. K.; Giachero, A.; Gironi, L.; Giuliani, A.; Gorla, P.; Gotti, C.; Gutierrez, T. D.; Haller, E. E.; Han, K.; Heeger, K. M.; Hennings-Yeomans, R.; Hickerson, K. P.; Huang, H. Z.; Kadel, R.; Keppel, G.; Kolomensky, Yu. G.; Li, Y. L.; Ligi, C.; Lim, K. E.; Liu, X.; Ma, Y. G.; Maiano, C.; Maino, M.; Martinez, M.; Maruyama, R. H.; Mei, Y.; Morganti, S.; Napolitano, T.; Nisi, S.; C. Nones; Norman, E. B.; Nucciotti, A.; O’Donnell, T.; Orio, F.; Orlandi, D.; Ouellet, J. L.; Pagliarone, C. E.; Pallavicini, M.; Palmieri, V.; Pattavina, L.; Pavan, M.; Pessina, G.; Pettinacci, V.; Piperno, G.; Pira, C.; Pirro, S.; Pozzi, S.; Previtali, E.; Rosenfeld, C.; Rusconi, C.; Sala, E.; Sangiorgio, S.; Santone, D.; Scielzo, N. D.; Sisti, M.; Smith, A. R.; Taffarello, L.; Tenconi, M.; Terranova, F.; Tian, W. D.; Tomei, C.; Trentalange, S.; Ventura, G.; Vignati, M.; Wang, B. S.; Wang, H. W.; Wielgus, L.; Wilson, J.; Winslow, L. A.; Wise, T.; Woodcraft, A.; Zanotti, L.; Zarra, C.; Zhang, G. Q.; Zhu, B. X.; Zucchelli, S.; Fabbri, F.; Giacomelli, P.

    2015-03-24

    The Cryogenic Underground Observatory for Rare Events (CUORE) is an upcoming experiment designed to search for the neutrinoless double-beta decays. Observation of the process would unambiguously establish that neutrinos are Majorana particles and provide information on their absolute mass scale hierarchy. CUORE is now under construction and will consist of an array of 988 TeO2 crystal bolometers operated at 10 mK, but the first tower (CUORE-0) is already taking data. The experimental techniques used will be presented as well as the preliminary CUORE-0 results. The current status of the full-mass experiment and its expected sensitivity will then be discussed.

  10. Neutrinoless double-beta decay search with CUORE and CUORE-0 experiments

    DOE PAGES

    Moggi, N.; Artusa, D. R.; F. T. Avignone; ...

    2015-03-24

    The Cryogenic Underground Observatory for Rare Events (CUORE) is an upcoming experiment designed to search for the neutrinoless double-beta decays. Observation of the process would unambiguously establish that neutrinos are Majorana particles and provide information on their absolute mass scale hierarchy. CUORE is now under construction and will consist of an array of 988 TeO2 crystal bolometers operated at 10 mK, but the first tower (CUORE-0) is already taking data. The experimental techniques used will be presented as well as the preliminary CUORE-0 results. The current status of the full-mass experiment and its expected sensitivity will then be discussed.

  11. Status and future of nuclear matrix elements for neutrinoless double-beta decay: a review.

    PubMed

    Engel, Jonathan; Menéndez, Javier

    2017-04-01

    The nuclear matrix elements that govern the rate of neutrinoless double beta decay must be accurately calculated if experiments are to reach their full potential. Theorists have been working on the problem for a long time but have recently stepped up their efforts as ton-scale experiments have begun to look feasible. Here we review past and recent work on the matrix elements in a wide variety of nuclear models and discuss work that will be done in the near future. Ab initio nuclear-structure theory, which is developing rapidly, holds out hope of more accurate matrix elements with quantifiable error bars.

  12. Status Update of the Majorana Demonstrator Neutrinoless Double Beta Decay Experiment

    SciTech Connect

    Gruzko, Julieta; Rielage, Keith Robert; Xu, Wenqin; Elliott, Steven Ray; Massarczyk, Ralph; Goett, John Jerome III; Chu, Pinghan

    2015-11-10

    Neutrinoless double beta decay searches play a major role in determining neutrino properties, in particular the Majorana or Dirac nature of the neutrino and the absolute scale of the neutrino mass. The consequences of these searches go beyond neutrino physics, with implications for Grand Unification and leptogenesis. The Majorana Collaboration is assembling a low-background array of high purity Germanium (HPGe) detectors to search for neutrinoless double-beta decay in 76Ge. The Majorana Demonstrator, which is currently being constructed and commissioned at the Sanford Underground Research Facility in Lead, South Dakota, will contain 44 kg (30 kg enriched in 76Ge) of HPGe detectors. Its primary goal is to demonstrate the scalability and background required for a tonne-scale Ge experiment. This is accomplished via a modular design and projected background of less than 3 cnts/tonne-yr in the region of interest. The experiment is currently taking data with the first of its enriched detectors.

  13. Cryogenic detectors for dark matter search and neutrinoless double beta decay

    NASA Astrophysics Data System (ADS)

    Münster, Andrea; Schönert, Stefan; Willers, Michael

    2017-02-01

    The search for the neutrinoless double beta decay and the direct search for dark matter particles are amongst the most fundamental questions in astroparticle physics and cosmology. To achieve a high sensitivity, detectors with an excellent energy resolution and highly efficient particle identification capabilities are required. In recent years, cryogenic particle detectors have become one of the driving technologies in these fields. Future direct dark matter search experiments aim to improve the sensitivity for low mass dark matter particles (≲ 10 GeV /c2) down to the neutrino floor and the next generation of neutrinoless double beta decay experiments aims to improve the sensitivity on the half-life to ∼1026 -1027 years, corresponding to the parameter space predicted for the inverted mass ordering and degenerate mass range. To achieve these goals, significant improvements in detector performance and in radiopurity are required and both classes of experiments can benefit from the strong synergies in the fields of detector development and in the production of high purity single-crystals.

  14. Extracting Majorana properties from strong bounds on neutrinoless double beta decay

    NASA Astrophysics Data System (ADS)

    Ge, Shao-Feng; Lindner, Manfred

    2017-02-01

    Assuming that neutrinos are Majorana particles, we explore what information can be inferred from future strong limits (i.e. nonobservation) for neutrinoless double beta decay. Specifically we consider the case where the mass hierarchy is normal and the different contributions to the effective mass ⟨m ⟩e e partly cancel. We discuss how this fixes the two Majorana C P phases simultaneously from the Majorana triangle and how it limits the lightest neutrino mass m1 within a narrow window. The two Majorana C P phases are in this case even better determined than in the usual case for larger ⟨m ⟩ee. We show that the uncertainty in these predictions can be significantly reduced by the complementary measurement of reactor neutrino experiments, especially the medium baseline version JUNO/RENO-50. We also estimate the necessary precision on ⟨m ⟩ee to infer nontrivial Majorana C P phases and the upper limit ⟨m ⟩ee≲1 meV sets a target for the design of future neutrinoless double beta decay experiments.

  15. Search for Neutrinoless Double-Beta Decay of with CUORE-0

    DOE PAGES

    Alfonso, K.; Artusa, D.  R.; F. T. Avignone; ...

    2015-09-03

    We report the results of a search for neutrinoless double-beta decay in a 9.8 kg yr exposure of 130Te using a bolometric detector array, CUORE-0. The characteristic detector energy resolution and background level in the region of interest are 5.1 ± 0.3 keV FWHM and 0.058 ± 0.004 (stat.) ± 0:002 (syst.) counts/(keV kg yr), respectively. The median 90% C.L. lower-limit sensitivity of the experiment is 2.9 x 1024 yr and surpasses the sensitivity of previous searches. We find no evidence for neutrinoless double-beta decay of 130Te and place a Bayesian lower bound on the decay half-life, T0more » $$_1$$1/2 > 2.7 x 1024 yr at 90% C.L. Combining CUORE-0 data with the 19.75 kg yr exposure of 130Te from the Cuoricino experiment we obtain T0$$_1$$1/2 > 4.0 x 1024 yr at 90% C.L. (Bayesian), the most stringent limit to date on this half-life. Using a range of nuclear matrix element estimates we interpret this as a limit on the effective Majorana neutrino mass, mββ < 270 - 760 meV.« less

  16. The COBRA experiment - Status and prospects on the search of neutrinoless double beta-decay

    NASA Astrophysics Data System (ADS)

    Zatschler, S.

    2015-10-01

    The Cadmium-Zinc-Telluride 0-ν Double Beta Research Apparatus (COBRA) [1] is a next-generation experiment searching for the existence of neutrinoless double beta-decay (0νββ-decay). The observation of 0νββ-decay would be an unambiguous sign for physics beyond the Standard Model such as lepton number violating processes and would prove the Majorana character of neutrinos. Furthermore, the study of 0νββ-decay could probe the absolute neutrino mass and allows for the identification of the neutrino mass hierarchy realized in nature assuming light Majorana neutrino exchange. Currently a demonstrator setup at the underground facility LNGS (Italy) built of 4×4×4 coplanar grid (CPG) detectors collects high quality low background physics data with FADC pulse shape sampling. The detectors are made of natural abundant CdZnTe (CZT), which is a commercially available room temperature semiconductor. It contains several double beta isotopes, the most promising of which is 116Cd with a Q-value of 2813.5 keV - which is well above the highest naturally occurring prominent γ-lines.

  17. The COBRA experiment – Status and prospects on the search of neutrinoless double beta-decay

    SciTech Connect

    Zatschler, S.

    2015-10-28

    The Cadmium-Zinc-Telluride 0-ν Double Beta Research Apparatus (COBRA) [1] is a next-generation experiment searching for the existence of neutrinoless double beta-decay (0νββ-decay). The observation of 0νββ-decay would be an unambiguous sign for physics beyond the Standard Model such as lepton number violating processes and would prove the Majorana character of neutrinos. Furthermore, the study of 0νββ-decay could probe the absolute neutrino mass and allows for the identification of the neutrino mass hierarchy realized in nature assuming light Majorana neutrino exchange. Currently a demonstrator setup at the underground facility LNGS (Italy) built of 4×4×4 coplanar grid (CPG) detectors collects high quality low background physics data with FADC pulse shape sampling. The detectors are made of natural abundant CdZnTe (CZT), which is a commercially available room temperature semiconductor. It contains several double beta isotopes, the most promising of which is {sup 116}Cd with a Q-value of 2813.5 keV – which is well above the highest naturally occurring prominent γ-lines.

  18. Background constrains of the SuperNEMO experiment for neutrinoless double beta-decay searches

    NASA Astrophysics Data System (ADS)

    Povinec, Pavel P.

    2017-02-01

    The SuperNEMO experiment is a new generation of experiments dedicated to the search for neutrinoless double beta-decay, which if observed, would confirm the existence of physics beyond the Standard Model. It is based on the tracking and calorimetry techniques, which allow the reconstruction of the final state topology, including timing and kinematics of the double beta-decay transition events, offering a powerful tool for background rejection. While the basic detection strategy of the SuperNEMO detector remains the same as of the NEMO-3 detector, a number of improvements were accomplished for each of detector main components. Upgrades of the detector technologies and development of low-level counting techniques ensure radiopurity control of construction parts of the SuperNEMO detector. A reference material made of glass pellets has been developed to assure quality management and quality control of radiopurity measurements. The first module of the SuperNEMO detector (Demonstrator) is currently under construction in the Modane underground laboratory. No background event is expected in the neutrinoless double beta-decay region in 2.5 years of its operation using 7 kg of 82Se. The half-life sensitivity of the Demonstrator is expected to be >6.5·1024 y, corresponding to an effective Majorana neutrino mass sensitivity of |0.2-0.4| eV (90% C.L.). The full SuperNEMO experiment comprising of 20 modules with 100 kg of 82Se source should reach an effective Majorana neutrino mass sensitivity of |0.04-0.1| eV, and a half-life limit 1·1026 y.

  19. Combining data from high-energy pp-reactions and neutrinoless double-beta decay: Limits on the mass of the right-handed boson

    NASA Astrophysics Data System (ADS)

    Civitarese, Osvaldo; Suhonen, Jouni; Zuber, Kai

    2016-10-01

    From the recently established lower-limits on the nonobservability of the neutrinoless double-beta decay of 76Ge (GERDA collaboration) and 136Xe (EXO-200 and KamLAND-Zen collaborations), combined with the ATLAS and CMS data, we extract limits for the left-right (LR) mixing angle, ζ, of the SU(2)L ×SU(2)R electroweak Hamiltonian. For the theoretical analysis, which is a model dependent, we have adopted a minimal extension of the Standard Model (SM) of Electroweak Interactions belonging to the SU(2)L ×SU(2)R representation. The nuclear-structure input of the analysis consists of a set of matrix elements and phase-space factors, and the experimental lower-limits for the half-lives. The other input are the ATLAS and CMS cross-section measurements of the pp-collisions into two-jets and two-leptons, performed at the large hadron collider (LHC). Our analysis yields the limit ζ < 10-3 for MR > 3TeV, by combining the model-dependent limits extracted from the double-beta-decay measurements and those extracted from the results of the CMS and ATLAS measurements.

  20. The Majorana Double Beta Decay Experiment: Present Status

    SciTech Connect

    Aguayo, Estanislao; Avignone, Frank T.; Back, Henning O.; Barabash, Alexander S.; Beene, Jim; Bergevin, M.; Bertrand, F.; Boswell, M.; Brudanin, V.; Busch, Matthew; Chan, Yuen-Dat; Christofferson, C. D.; Collar, J. I.; Combs, Dustin C.; Cooper, R. J.; Detwiler, Jason A.; Doe, Peter J.; Efremenko, Yuri; Egorov, Viatcheslav; Ejiri, H.; Elliott, S. R.; Esterline, James H.; Fast, James E.; Fields, N.; Finnerty, P.; Fraenkle, Florian; Gehman, Victor M.; Giovanetti, G. K.; Green, M. P.; Guiseppe, V. E.; Gusey, K.; Hallin, A. L.; Hazama, R.; Henning, Reyco; Hime, Andrew; Hoppe, Eric W.; Horton, Mark; Howard, Stanley; Howe, M. A.; Johnson, R. A.; Keeter, K.; Keller, C.; Kidd, M. F.; Knecht, A.; Kochetov, Oleg; Konovalov, S.; Kouzes, Richard T.; Laferriere, Brian D.; LaRoque, B. H.; Leon, Jonathan D.; Leviner, L.; Loach, J. C.; MacMullin, S.; Marino, Michael G.; Martin, R. D.; Mei, Dong-Ming; Merriman, Jason H.; Miller, M. L.; Mizouni, Leila; Nomachi, Masaharu; Orrell, John L.; Overman, Nicole R.; Phillips II, D. G.; Poon, Alan; Perumpilly, Gopakumar; Prior, Gersende; Radford, D. C.; Rielage, Keith; Robertson, R. G. H.; Ronquest, M. C.; Schubert, Alexis G.; Shima, T.; Shirchenko, M.; Snavely, Kyle J.; Steele, David; Strain, J.; Thomas, K.; Timkin, V.; Tornow, W.; Vanyushin, I.; Varner, R. L.; Vetter, Kai; Vorren, Kris R.; Wilkerson, J. F.; Yakushev, E.; Young, A.; Yu, Chang-Hong; Yumatov, Vladimir; Zhang, C.

    2013-06-01

    The Majorana collaboration is actively pursuing research and development aimed at a tonne-scale 76Ge neutrinoless double-beta decay experiment, an R&D effort that will field approximately 40 kg of germanium detectors with mixed enrichment levels. This article provides a status update on the construction of the Demonstrator

  1. MOON for a next-generation neutrino-less double-beta decay experiment: Present status and perspective

    SciTech Connect

    Shima, T.; Doe, P.J.; Ejiri, H.; Elliot, S.R.; Engel, J.; Finger, M.; Finger, M.; Fushimi, K.; Gehman, V.M.; Greenfield, M.B.; Hazama, R.; /Hiroshima U. /NIRS, Chiba

    2008-01-01

    The performance of the MOON detector for a next-generation neutrino-less double-beta decay experiment was evaluated by means of the Monte Carlo method. The MOON detector was found to be a feasible solution for the future experiment to search for the Majorana neutrino mass in the range of 100-30 meV.

  2. MOON for a next-generation neutrino-less double-beta decay experiment; present status and perspective

    NASA Astrophysics Data System (ADS)

    Shima, T.; Doe, P. J.; Ejiri, H.; Elliot, S. R.; Engel, J.; Finger, M.; Finger, M., Jr.; Fushimi, K.; Gehman, V. M.; Greenfield, M. B.; Hazama, R.; Imaseki, H.; Kavitov, P.; Kekelidze, V. D.; Kitamura, H.; Matsuoka, K.; Nakamura, H.; Nomachi, M.; Para, A.; Robertson, R. G. H.; Slunecka, M.; Shirkov, G. D.; Sissakian, A. N.; Titov, A. I.; Uchihori, Y.; Umehara, S.; Vaturin, V.; Voronov, V. V.; Wilkerson, J. F.; Will, D. I.; Yasuda, K.; Yoshida, S.

    2008-07-01

    The performance of the MOON detector for a next-generation neutrino-less double-beta decay experiment was evaluated by means of the Monte Carlo method. The MOON detector was found to be a feasible solution for the future experiment to search for the Majorana neutrino mass in the range of 100-30 meV.

  3. Anti-Reflective Coatings R&D for Next Generation Neutrinoless Double Beta Experiments

    NASA Astrophysics Data System (ADS)

    Leder, Alexander; Cuore Collaboration

    2016-03-01

    The Cyogenic Underground Observatory for Rare Events (CUORE) is a ton-scale cryogenic source=detector experiment designed to search for the Neutrinoless Double Beta Decay (0 νββ) of 130Te. CUORE currently utilizes a single phonon readout channel per crystal; adding a second channel for scintillation or Cherenkov light would improve particle identification for actively rejecting background events. This light would be collected via semiconductor wafers covered with anti-reflective coatings. These coatings maximize light absorption. In this talk, I will discuss the coating optimization regarding material and structure, and its implications for designing the next generation CUORE-style experiment. In addition, I will discuss projections for possible sensitivities of next generation 0 νββ searches that use dual channel light-phonon readouts.

  4. A search for neutrinoless double beta decay of [sup 130]Te with a low temperature calorimeter

    SciTech Connect

    Alessandrello, A. ); Brofferio, C. ); Camin, D.V.; Cremonesi, O.; Gervasio, G.; Fiorini, E.; Giuliani, A.; Pavan, M.; Pessina, G.; Previtali, E.; Zanotti, L. )

    1992-02-05

    Possible impacts of the bolometric technique on Neutrinoless Double Beta Decay (0[nu]-DVD) search are discussed. In this approach, the performances of two TeO[sub 2] low temperature calorimeters with masses of 73 g and 340 g are reported: the FWHM resolutions are respectively 6 keV and 20 keV at 2614 keV. The operation of these detectors in a low background environment in the Gran Sasso underground laboratory has allowed to set a limit on the half-life of [sup 130]Te 2[nu]-DBD of about 2.5[times]10[sup 21] and to study the residual radioactive background components.

  5. The search for Majorana neutrinos with neutrinoless double beta decays: From CUORICINO to LUCIFER experiment

    SciTech Connect

    Bellini, F.

    2012-11-20

    The study of neutrino properties is one of the fundamental challenges in particle physics nowadays. Fifty years of investigations established that neutrinos are massive but the absolute mass scale has not yet been measured. Moreover its true nature is still unknown. Is the neutrino its own antiparticle (thus violating the lepton number) as proposed by Majorana in 1937? The only way to probe the neutrino nature is through the observation of Neutrinoless Double Beta Decay (0{nu}{beta}{beta}), a very rare spontaneous nuclear transition which emits two electrons and no neutrinos. In this paper, after a brief introduction to the theoretical framework of Majorana's neutrino, a presentation of experimental challenges posed by 0{nu}{beta}{beta} search will be given as well as an overview of present status and future perpectives of experiments.

  6. The DCBA/MTD Experiments for Neutrinoless Double Beta Decay Search

    NASA Astrophysics Data System (ADS)

    Iwase, H.; Kakuno, H.; Ishihara, N.; Kawai, M.; Kondou, Y.; Makida, Y.; Iwai, G.; Ohama, T.; Takahashi, K.; Yamada, Y.; Inagaki, T.; Kato, Y.; Tanaka, K.; Tonooka, M.; Kitamura, S.; Sumiyoshi, T.; Tajima, T.; Ishizuka, T.; Ito, R.; Tamura, N.; Nakano, I.; Nagasaka, Y.; Sakamoto, Y.; Teramoto, Y.

    Both experiments Drift Chamber Beta-ray Analyzer and Magnetic Tracking Detector (DCBA/MTD) aim at searches for neutrinoless double beta decay (0νββ) in several nuclei. If 0νββ would be observed, Majorana nature of neutrino would be confirmed. This means that the See-saw mechanism would be supported and Leptogenesis would be hopeful in early universe. And also the half-life measurement of 0νββ would determine the absolute mass scale of neutrinos. DCBA can obtain four-momentum of each beta-ray so that not only the energy of two beta-rays each, but also the angular correlations are measured directly. Since the method has a large number of new experimental techniques, DCBA has been placed as an R&D experiment for a future large scale experiment MTD. This paper describes the present status of DCBA and the design of MTD.

  7. Superconducting solenoid magnet of the DCBA-T3 experiment searching for neutrinoless double beta decay

    NASA Astrophysics Data System (ADS)

    Kawai, M.; Kondou, Y.; Makida, Y.; Haruyama, T.; Ishihara, N.; Kobayashi, Y.; Iwai, G.; Iwase, H.; Ohama, T.; Takahashi, K.; Yamada, Y.; Kato, Y.; Tanaka, K.; Tonooka, M.; Kitamura, S.; Ishikawa, T.; Igarashi, H.; Kakuno, H.; Sumiyoshi, T.; Tajima, T.; Ishizuka, T.; Ito, R.; Tamura, N.

    2014-03-01

    The experiment of neutrinoless double beta decay (0ν β β) is the only realistic method for investigating the Majorana nature and the absolute mass scale of neutrinos. An R&D project called Drift Chamber Beta-ray Analyzer (DCBA) has been developing a magnetic tracking detector for 0ν β β experiments at KEK. A superconducting solenoid magnet (SCSM) has been constructed to produce a uniform magnetic field for the prototype test facility called DCBA-T3. The results of SCSM test runs are described, as well as its design studies. Since the SCSM is a prototype magnet for a future detector temporarily called Magnetic Tracking Detector (MTD), it is essential to understand its long-term operation. The experience of about two years of operation is also described.

  8. Magnetic tracking detector DCBA/MTD for neutrinoless double beta decay experiments

    NASA Astrophysics Data System (ADS)

    Ishihara, Nobuhiro; DCBA Collaboration

    2012-07-01

    Magnetic tracking detector is being developed at KEK for neutrinoless double beta decay experiments. Drift Chamber Beta-ray Analyzer (DCBA) is an R&D program to confirm the detection principle of the magnetic tracking detector. A prototype called DCBA-T2 has been constructed and operated to investigate its energy resolution and operation problems. Another new prototype DCBA-T3 is now under construction to improve the energy resolution and the amount of decay source. On the basis on DCBA-T2&T3, we have designed a future project temporarily called Magnetic Tracking Detector (MTD). One module of MTD will be able to accommodate a lot of decay source, so that several ten modules will give us a chance to investigate the effective neutrino mass down to 30 meV.

  9. AXEL-a high pressure xenon gas TPC for neutrinoless double beta decay search

    NASA Astrophysics Data System (ADS)

    Nakamura, Kiseki; Ichikawa, Atsuko K.; Nakaya, Tsuyoshi; Minamino, Akihiro; Ban, Sei; Yanagita, Saori; Tanaka, Shunsuke; Hirose, Masanori; Sekiya, Hiroyuki; Ueshima, Kota; Miuchi, Kentaro

    2017-02-01

    To search for neutrinoless double beta decay, we have started developing a high pressure xenon gas time projection chamber as the AXEL (A Xenon ElectroLuminescence detector) project since 2014. We proposed a new scheme to measure energy deposit using electroluminescence lights to achieve high energy resolution, large mass and strong background rejection power. Important performances of compositions of our new readout scheme are shown: electric field simulation, VUV sensitivity of MPPC in high pressure gaseous xenon, response of MPPC for large amount of photons. To demonstrate as a whole system, we constructed a small prototype detector using 64 MPPCs filled with 4 bar xenon gas. Result of measurement with a 57Co gamma-ray source are shown.

  10. Pions in nuclei and manifestations of supersymmetry in neutrinoless double beta decay

    NASA Astrophysics Data System (ADS)

    Faessler, Amand; Kovalenko, Sergey; Šimkovic, Fedor

    1998-12-01

    We examine the pion realization of the short-ranged supersymmetric (SUSY) mechanism of neutrinoless double beta decay (0νββ decay). It originates from the R-parity violating quark-lepton interactions of the SUSY extensions of the standard model of the electroweak interactions. We argue that pions are dominant SUSY mediators in 0νββ decay. The corresponding nuclear matrix elements for potentially 0νββ-decaying isotopes are calculated within the proton-neutron renormalized quasiparticle random-phase approximation (pn-RQRPA). We define those isotopes which are most sensitive to the SUSY signal and provide an outlook on the present experimental situation with the 0νββ-decay searches for SUSY. Upper limits on the R-parity violating first-generation Yukawa coupling λ'111 are derived from various 0νββ experiments.

  11. An update on the neutrinoless double beta decay search at Cuoricino

    NASA Astrophysics Data System (ADS)

    Gutierrez, Thomas D.

    2004-10-01

    We present a status report on the neutrinoless double beta (0ν2β) decay search efforts at Cuoricino, a bolometric experiment located at the Gran Sasso Laboratory in Italy. In particular, we provide an update on the ongoing hardware development and parallel analysis efforts at LBNL. Cuoricino consists of a single tower of 62 TeO2 crystals ( ˜ 40 kg), which serve as both the source and detector for the 0ν2β decays. We also discuss the proposed CUORE (Cryogenic Underground Observatory for Rare Events) experiment. Similar in concept to Cuoricino, CUORE will consist of 1000 TeO2 crystals having a total mass of approximately 760 kg. CUORE will provide more statistics and, along with various anticipated technical improvements, higher sensitivity to 0ν2β decays than Cuoricino. This work is supported by the US Department of Energy.

  12. Search for Neutrinoless Double-Beta Decay of with CUORE-0

    SciTech Connect

    Alfonso, K.; Artusa, D.  R.; F. T. Avignone; Azzolini, O.; Balata, M.; Banks, T.  I.; Bari, G.; Beeman, J.  W.; Bellini, F.; Bersani, A.; Biassoni, M.; Brofferio, C.; Bucci, C.; Caminata, A.; Canonica, L.; Cao, X.  G.; Capelli, S.; Cappelli, L.; Carbone, L.; Cardani, L.; Casali, N.; Cassina, L.; Chiesa, D.; Chott, N.; Clemenza, M.; Copello, S.; Cosmelli, C.; Cremonesi, O.; Creswick, R.  J.; Cushman, J.  S.; Dafinei, I.; Dally, A.; Dell’Oro, S.; Deninno, M.  M.; Di Domizio, S.; Di Vacri, M.  L.; Drobizhev, A.; Ejzak, L.; Fang, D.  Q.; Faverzani, M.; Fernandes, G.; Ferri, E.; Ferroni, F.; Fiorini, E.; Freedman, S.  J.; Fujikawa, B.  K.; Giachero, A.; Gironi, L.; Giuliani, A.; Gorla, P.; Gotti, C.; Gutierrez, T.  D.; Haller, E.  E.; Han, K.; Hansen, E.; Heeger, K.  M.; Hennings-Yeomans, R.; Hickerson, K.  P.; Huang, H.  Z.; Kadel, R.; Keppel, G.; Kolomensky, Yu.  G.; Lim, K.  E.; Liu, X.; Ma, Y.  G.; Maino, M.; Martinez, M.; Maruyama, R.  H.; Mei, Y.; Moggi, N.; Morganti, S.; Nisi, S.; C. Nones; Norman, E.  B.; Nucciotti, A.; O’Donnell, T.; Orio, F.; Orlandi, D.; Ouellet, J.  L.; Pagliarone, C.  E.; Pallavicini, M.; Palmieri, V.; Pattavina, L.; Pavan, M.; Pedretti, M.; Pessina, G.; Pettinacci, V.; Piperno, G.; Pirro, S.; Pozzi, S.; Previtali, E.; Rosenfeld, C.; Rusconi, C.; Sala, E.; Sangiorgio, S.; Santone, D.; Scielzo, N.  D.; Sisti, M.; Smith, A.  R.; Taffarello, L.; Tenconi, M.; Terranova, F.; Tomei, C.; Trentalange, S.; Ventura, G.; Vignati, M.; Wagaarachchi, S.  L.; Wang, B.  S.; Wang, H.  W.; Wielgus, L.; Wilson, J.; Winslow, L.  A.; Wise, T.; Zanotti, L.; Zarra, C.; Zhang, G.  Q.; Zhu, B.  X.; Zucchelli, S.

    2015-09-03

    We report the results of a search for neutrinoless double-beta decay in a 9.8 kg yr exposure of 130Te using a bolometric detector array, CUORE-0. The characteristic detector energy resolution and background level in the region of interest are 5.1 ± 0.3 keV FWHM and 0.058 ± 0.004 (stat.) ± 0:002 (syst.) counts/(keV kg yr), respectively. The median 90% C.L. lower-limit sensitivity of the experiment is 2.9 x 1024 yr and surpasses the sensitivity of previous searches. We find no evidence for neutrinoless double-beta decay of 130Te and place a Bayesian lower bound on the decay half-life, T0$_1$1/2 > 2.7 x 1024 yr at 90% C.L. Combining CUORE-0 data with the 19.75 kg yr exposure of 130Te from the Cuoricino experiment we obtain T0$_1$1/2 > 4.0 x 1024 yr at 90% C.L. (Bayesian), the most stringent limit to date on this half-life. Using a range of nuclear matrix element estimates we interpret this as a limit on the effective Majorana neutrino mass, mββ < 270 - 760 meV.

  13. The AMoRE: Search for neutrinoless double beta decay of {sup 100}Mo

    SciTech Connect

    Park, HyangKyu

    2015-10-28

    The AMoRE (Advanced Mo-based Rare process Experiment) collaboration is using calcium molybdate ({sup dep48}Ca {sup 100}MoO{sub 4}) crystals enriched in {sup 100}Mo and depleted in {sup 48}Ca to search for neutrinoless double-beta decay (DBD) of {sup 100}Mo using at the underground laboratory in Korea. Metallic magnetic calorimeters operating a milliKelvin temperatures are used as temperature sensors to measure heat and light signals from the crystals. The simultaneous and fast detection capabilities for both phonons and photons, and their excellent energy resolution provide powerful methods for identifying DBD signals and rejecting background events, which are mainly due to random coincidences between two uncorrelated two-neutrino-double-beta decays of {sup 100}Mo. The AMoRE-Pilot experiment that is currently underway uses a 1.5 kg, five-element array of {sup dep48}Ca {sup 100}MoO{sub 4} crystals. The ultimate goal is a ∼200 kg array of crystals and a half-life sensitivity of order 10{sup 26} years, which will access the inverted hierarchy region for effective Majorana neutrino masses, i.e., 0.02 to 0.05 eV. In this talk, we present recent progress on the development of low-background calcium molybdate detectors and results from room- and milli-Kelvin temperatures. Sensitivities based on GEANT4 simulations that incorporate measured background are reported.

  14. The AMoRE: Search for neutrinoless double beta decay of 100Mo

    NASA Astrophysics Data System (ADS)

    Park, HyangKyu

    2015-10-01

    The AMoRE (Advanced Mo-based Rare process Experiment) collaboration is using calcium molybdate (dep48Ca 100MoO4) crystals enriched in 100Mo and depleted in 48Ca to search for neutrinoless double-beta decay (DBD) of 100Mo using at the underground laboratory in Korea. Metallic magnetic calorimeters operating a milliKelvin temperatures are used as temperature sensors to measure heat and light signals from the crystals. The simultaneous and fast detection capabilities for both phonons and photons, and their excellent energy resolution provide powerful methods for identifying DBD signals and rejecting background events, which are mainly due to random coincidences between two uncorrelated two-neutrino-double-beta decays of 100Mo. The AMoRE-Pilot experiment that is currently underway uses a 1.5 kg, five-element array of dep48Ca 100MoO4 crystals. The ultimate goal is a ˜200 kg array of crystals and a half-life sensitivity of order 1026 years, which will access the inverted hierarchy region for effective Majorana neutrino masses, i.e., 0.02 to 0.05 eV. In this talk, we present recent progress on the development of low-background calcium molybdate detectors and results from room- and milli-Kelvin temperatures. Sensitivities based on GEANT4 simulations that incorporate measured background are reported.

  15. Measurement of the double-beta decay half-life and search for the neutrinoless double-beta decay of 48Ca with the NEMO-3 detector

    NASA Astrophysics Data System (ADS)

    Arnold, R.; Augier, C.; Bakalyarov, A. M.; Baker, J. D.; Barabash, A. S.; Basharina-Freshville, A.; Blondel, S.; Blot, S.; Bongrand, M.; Brudanin, V.; Busto, J.; Caffrey, A. J.; Calvez, S.; Cascella, M.; Cerna, C.; Cesar, J. P.; Chapon, A.; Chauveau, E.; Chopra, A.; Duchesneau, D.; Durand, D.; Egorov, V.; Eurin, G.; Evans, J. J.; Fajt, L.; Filosofov, D.; Flack, R.; Garrido, X.; Gómez, H.; Guillon, B.; Guzowski, P.; Hodák, R.; Huber, A.; Hubert, P.; Hugon, C.; Jullian, S.; Klimenko, A.; Kochetov, O.; Konovalov, S. I.; Kovalenko, V.; Lalanne, D.; Lang, K.; Lebedev, V. I.; Lemière, Y.; Le Noblet, T.; Liptak, Z.; Liu, X. R.; Loaiza, P.; Lutter, G.; Mamedov, F.; Marquet, C.; Mauger, F.; Morgan, B.; Mott, J.; Nemchenok, I.; Nomachi, M.; Nova, F.; Nowacki, F.; Ohsumi, H.; Pahlka, R. B.; Perrot, F.; Piquemal, F.; Povinec, P.; Přidal, P.; Ramachers, Y. A.; Remoto, A.; Reyss, J. L.; Richards, B.; Riddle, C. L.; Rukhadze, E.; Rukhadze, N. I.; Saakyan, R.; Salazar, R.; Sarazin, X.; Shitov, Yu.; Simard, L.; Šimkovic, F.; Smetana, A.; Smolek, K.; Smolnikov, A.; Söldner-Rembold, S.; Soulé, B.; Štekl, I.; Suhonen, J.; Sutton, C. S.; Szklarz, G.; Thomas, J.; Timkin, V.; Torre, S.; Tretyak, Vl. I.; Tretyak, V. I.; Umatov, V. I.; Vanushin, I.; Vilela, C.; Vorobel, V.; Waters, D.; Zhukov, S. V.; Žukauskas, A.; NEMO-3 Collaboration

    2016-06-01

    The NEMO-3 experiment at the Modane Underground Laboratory investigates the double-beta decay of 48Ca. Using 5.25 yr of data recorded with a 6.99 g sample of 48Ca, approximately 150 double-beta decay candidate events are selected with a signal-to-background ratio greater than 3. The half-life for the two-neutrino double-beta decay of 48Ca is measured to be T1/2 2 ν=[6. 4-0.6+0.7(stat)-0.9 +1.2(syst ) ]×1 019 yr . A search for neutrinoless double-beta decay of 48Ca yields a null result, and a corresponding lower limit on the half-life is found to be T1/2 0 ν>2.0 ×1 022 yr at 90% confidence level, translating into an upper limit on the effective Majorana neutrino mass of ⟨mβ β⟩<6.0 - 26 eV , with the range reflecting different nuclear matrix element calculations. Limits are also set on models involving Majoron emission and right-handed currents.

  16. Neutrinoless double beta decay in LRSM with natural type-II seesaw dominance

    NASA Astrophysics Data System (ADS)

    Pritimita, Prativa; Dash, Nitali; Patra, Sudhanwa

    2016-10-01

    We present a detailed discussion on neutrinoless double beta decay within a class of left-right symmetric models where neutrino mass originates by natural type-II seesaw dominance. The spontaneous symmetry breaking is implemented with doublets, triplets and bidoublet scalars. The fermion sector is extended with an extra sterile neutrino per generation that helps in implementing the seesaw mechanism. The presence of extra particles in the model exactly cancels type-I seesaw and allows large value for Dirac neutrino mass matrix M D . The key feature of this work is that all the physical masses and mixing are expressed in terms of neutrino oscillation parameters and lightest neutrino mass thereby facilitating to constrain light neutrino masses from 0ν ββ decay. With this large value of M D new contributions arise due to; i) purely left-handed current via exchange of heavy right- handed neutrinos as well as sterile neutrinos, ii) the so called λ and η diagrams. New physics contributions also arise from right-handed currents with right-handed gauge boson W R mass around 3 TeV. From the numerical study, we find that the new contributions to 0 νββ decay not only saturate the current experimental bound but also give lower limit on absolute scale of lightest neutrino mass and favor NH pattern of light neutrino mass hierarchy.

  17. Development of liquid scintillator containing a zirconium complex for neutrinoless double beta decay experiment

    NASA Astrophysics Data System (ADS)

    Fukuda, Yoshiyuki; Moriyama, Shigetaka; Ogawa, Izumi

    2013-12-01

    An organic liquid scintillator containing a zirconium complex has been developed for a new neutrinoless double beta decay experiment. In order to produce a detector that has good energy resolution (4% at 2.5 MeV) and low background (0.1 counts/(t·year)) and that can monitor tons of target isotope, we chose a zirconium β-diketone complex having high solubility (over 10 wt%) in anisole. However, the absorption peak of the diketone ligand overlaps with the luminescence of anisole. Therefore, the light yield of the liquid scintillator decreases in proportion to the concentration of the complex. To avoid this problem, we synthesized a β-keto ester complex introducing -OC3H7 or -OC2H5 substituent groups in the β-diketone ligand, which shifted the absorption peak to around 245 nm, which is shorter than the emission peak of anisole (275 nm). However, the shift of the absorption peak depends on the polarity of the scintillation solvent. Therefore we must choose a low polarity solvent for the liquid scintillator. We also synthesized a Zr-ODZ complex, which has a high quantum yield (30%) and good emission wavelength (425 nm) with a solubility 5 wt% in benzonitrile. However, the absorption peak of the Zr-ODZ complex was around 240 nm. Therefore, it is better to use the scintillation solvent which has shorter luminescence wavelength than that of the aromatic solvent.

  18. A realistic model of neutrino masses with a large neutrinoless double beta decay rate

    NASA Astrophysics Data System (ADS)

    del Aguila, Francisco; Aparici, Alberto; Bhattacharya, Subhaditya; Santamaria, Arcadi; Wudka, Jose

    2012-05-01

    The minimal Standard Model extension with the Weinberg operator does accommodate the observed neutrino masses and mixing, but predicts a neutrinoless double beta (0 νββ) decay rate proportional to the effective electron neutrino mass, which can be then arbitrarily small within present experimental limits. However, in general 0 νββ decay can have an independent origin and be near its present experimental bound; whereas neutrino masses are generated radiatively, contributing negligibly to 0 νββ decay. We provide a realization of this scenario in a simple, well defined and testable model, with potential LHC effects and calculable neutrino masses, whose two-loop expression we derive exactly. We also discuss the connection of this model to others that have appeared in the literature, and remark on the significant differences that result from various choices of quantum number assignments and symmetry assumptions. In this type of models lepton flavor violating rates are also preferred to be relatively large, at the reach of foreseen experiments. Interestingly enough, in our model this stands for a large third mixing angle, {{si}}{{{n}}^{{2}}}{θ_{{{13}}}}{˜}}}{ > }}0.00{8} , when μ→ eee is required to lie below its present experimental limit.

  19. GraXe, graphene and xenon for neutrinoless double beta decay searches

    SciTech Connect

    Gómez-Cadenas, J.J.; Martín-Albo, J.; Monrabal, F.; Vidal, J. Muñoz; Guinea, F.; Fogler, M.M.; Katsnelson, M.I. E-mail: paco.guinea@icmm.csic.es E-mail: katsnel@sci.kun.nl E-mail: francesc.monrabal@ific.uv.es

    2012-02-01

    We propose a new detector concept, GraXe (to be pronounced as grace), to search for neutrinoless double beta decay in {sup 136}XE. GraXe combines a popular detection medium in rare-event searches, liquid xenon, with a new, background-free material, graphene. In our baseline design of GraXe, a sphere made of graphene-coated titanium mesh and filled with liquid xenon (LXe) enriched in the {sup 136}XE isotope is immersed in a large volume of natural LXe instrumented with photodetectors. Liquid xenon is an excellent scintillator, reasonably transparent to its own light. Graphene is transparent over a large frequency range, and impermeable to the xenon. Event position could be deduced from the light pattern detected in the photosensors. External backgrounds would be shielded by the buffer of natural LXe, leaving the ultra-radiopure internal volume virtually free of background. Industrial graphene can be manufactured at a competitive cost to produce the sphere. Enriching xenon in the isotope {sup 136}XE is easy and relatively cheap, and there is already near one ton of enriched xenon available in the world (currently being used by the EXO, KamLAND-Zen and NEXT experiments). All the cryogenic know-how is readily available from the numerous experiments using liquid xenon. An experiment using the GraXe concept appears realistic and affordable in a short time scale, and its physics potential is enormous.

  20. Online Data Quality and Bad Interval Detection for the CUORE Neutrinoless Double Beta Decay Search

    NASA Astrophysics Data System (ADS)

    Welliver, Bradford; Cuore Collaboration

    2016-09-01

    The Cryogenic Underground Observatory for Rare Events (CUORE) is a large neutrinoless double beta decay (0 νββ) search being installed underground at the Laboratori Nazionali del Gran Sasso (LNGS). 0 νββ searches can address fundamental questions about the nature of the neutrino, such as whether it is a Dirac or MAJORANA fermion, its mass scale, and may provide insight into the observed matter-antimatter asymmetry in the universe. CUORE is the largest array of bolometer instrumented crystals in the world, nineteen times larger than the previous implementation used in CUORE-0, and contains a total of 988 TeO2 crystals with a mass of 741kg and is expected to achieve a sensitivity on the 130Te 0 νββ half-life of T1 / 2 = 9 . 5 x 1025 years (90 % C.L.) after 5 years of operation. The large number of individual crystals in CUORE presents challenges for monitoring data quality and the determination of bad intervals of time in detector operation. We will discuss the work being performed to provide expanded online detector quality monitoring tools as well as the development of automated algorithms to test and identify periods of abnormal behavior across all of the individual detectors.

  1. The contribution of light Majorana neutrinos to neutrinoless double beta decay and cosmology

    SciTech Connect

    Dell’Oro, S.; Marcocci, S.; Viel, M.; Vissani, F.

    2015-12-11

    Cosmology is making impressive progress and it is producing stringent bounds on the sum of the neutrino masses Σ, a parameter of great importance for the current laboratory experiments. In this letter, we exploit the potential relevance of the analysis of Palanque-Delabrouille et al. to the neutrinoless double beta decay (0νββ) search. This analysis indicates small values for the lightest neutrino mass, since the authors find Σ<84 meV at 1σ C.L., and provides a 1σ preference for the normal hierarchy. The allowed values for the Majorana effective mass, probed by 0νββ, turn out to be <75 meV at 3σ C.L. and lower down to less than 20 meV at 1σ C.L. . If this indication is confirmed, the impact on the 0νββ experiments will be tremendous since the possibility of detecting a signal will be out of the reach of the next generation of experiments.

  2. Exploring the Neutrinoless Double Beta Decay in the Inverted Neutrino Hierarchy with Bolometric Detectors

    DOE PAGES

    Artusa, D. R.; Azzolini, O.; Balata, M.; ...

    2014-10-15

    Neutrinoless double beta decay (0νββ) is one of the most sensitive probes for physics beyond the Standard Model, providing unique information on the nature of neutrinos. In this paper we review the status and outlook for bolometric 0νββ decay searches. We summarize recent advances in background suppression demonstrated using bolometers with simultaneous readout of heat and light signals. We simulate several configurations of a future CUORE-like bolometer array which would utilize these improvements and present the sensitivity reach of a hypothetical next-generation bolometric0νββ experiment. We demonstrate that a bolometric experiment with the isotope mass of about 1 ton is capablemore » of reaching the sensitivity to the effective Majorana neutrino mass (|mee|) of order 10-20 meV, thus completely exploring the so-called inverted neutrino mass hierarchy region. In conclusion, we highlight the main challenges and identify priorities for an R&D program addressing them.« less

  3. Theoretical uncertainties in the nuclear matrix elements of neutrinoless double beta decay: The transition operator

    SciTech Connect

    Menéndez, Javier

    2013-12-30

    We explore the theoretical uncertainties related to the transition operator of neutrinoless double-beta (0νββ) decay. The transition operator used in standard calculations is a product of one-body currents, that can be obtained phenomenologically as in Tomoda [1] or Šimkovic et al. [2]. However, corrections to the operator are hard to obtain in the phenomenological approach. Instead, we calculate the 0νββ decay operator in the framework of chiral effective theory (EFT), which gives a systematic order-by-order expansion of the transition currents. At leading orders in chiral EFT we reproduce the standard one-body currents of Refs. [1] and [2]. Corrections appear as two-body (2b) currents predicted by chiral EFT. We compute the effects of the leading 2b currents to the nuclear matrix elements of 0νββ decay for several transition candidates. The 2b current contributions are related to the quenching of Gamow-Teller transitions found in nuclear structure calculations.

  4. Deformed shell model results for neutrinoless double beta decay of nuclei in A = 60 - 90 region

    NASA Astrophysics Data System (ADS)

    Sahu, R.; Kota, V. K. B.

    2015-03-01

    Nuclear transition matrix elements (NTME) for the neutrinoless double beta decay (Oνββ or OνDBD) of 70Zn, 80Se and 82Se nuclei are calculated within the framework of the deformed shell model (DSM) based on Hartree-Fock (HF) states. For 70Zn, jj44b interaction in 2p3/2, 1f5/2, 2p1/2 and 1g9/2 space with 56Ni as the core is employed. However, for 80Se and 82Se nuclei, a modified Kuo interaction with the above core and model space are employed. Most of our calculations in this region were performed with this effective interaction. However, jj44b interaction has been found to be better for 70Zn. The above model space was used in many recent shell model (SM) and interacting boson model (IBM) calculations for nuclei in this region. After ensuring that DSM gives good description of the spectroscopic properties of low-lying levels in these three nuclei considered, the NTME are calculated. The deduced half-lives with these NTME, assuming neutrino mass is 1 eV, are 1.1 × 1026, 2.3 × 1027 and 2.2 × 1024 yr for 70Zn, 80Se and 82Se, respectively.

  5. Exploring the Neutrinoless Double Beta Decay in the Inverted Neutrino Hierarchy with Bolometric Detectors

    SciTech Connect

    Artusa, D. R.; Azzolini, O.; Balata, M.; Banks, T. I.; Bari, G.; Beeman, J.; Bellini, F.; Bersani, A.; Biassoni, M.; Brofferio, C.; Bucci, C.; Cai, X. Z.; Camacho, A.; Canonica, L.; Cao, X. G.; Capelli, S.; Carbone, L.; Cardani, L.; Carrettoni, M.; Casali, N.; Chiesa, D.; Chott, N.; Clemenza, M.; Cosmelli, C.; Cremonesi, O.; Creswick, R. J.; Dafinei, I.; Dally, A.; Datskov, V.; Biasi, A. De; Deninno, M. M.; Domizio, S. Di; Vacri, M. L. di; Ejzak, L.; Fang, D. Q.; Farach, H. A.; Faverzani, M.; Fernandes, G.; Ferri, E.; Ferroni, F.; Fiorini, E.; Franceschi, M. A.; Freedman, S. J.; Fujikawa, B. K.; Giachero, A.; Gironi, L.; Giuliani, A.; Goett, J.; Gorla, P.; Gotti, C.; Gutierrez, T. D.; Haller, E. E.; Han, K.; Heeger, K. M.; Hennings-Yeomans, R.; Huang, H. Z.; Kadel, R.; Kazkaz, K.; Keppel, G.; Kolomensky, Yu. G.; Li, Y. L.; Ligi, C.; Liu, X.; Ma, Y. G.; Maiano, C.; Maino, M.; Martinez, M.; Maruyama, R. H.; Mei, Y.; Moggi, N.; Morganti, S.; Napolitano, T.; Nisi, S.; Norman, E. B.; Nucciotti, A.; O'Donnell, T.; Orio, F.; Orlandi, D.; Ouellet, J. L.; Pallavicini, M.; Palmieri, V.; Pattavina, L.; Pavan, M.; Pedretti, M.; Pessina, G.; Pettinacci, V.; Piperno, G.; Pira, C.; Pirro, S.; Previtali, E.; Rampazzo, V.; Rosenfeld, C.; Rusconi, C.; Sala, E.; Sangiorgio, S.; Scielzo, N. D.; Sisti, M.; Smith, A. R.; Taffarello, L.; Tenconi, M.; Terranova, F.; Tian, W. D.; Tomei, C.; Trentalange, S.; Ventura, G.; Vignati, M.; Wang, B. S.; Wang, H. W.; Wielgus, L.; Wilson, J.; Winslow, L. A.; Wise, T.; Woodcraft, A.; Zanotti, L.; Zarra, C.; Zhu, B. X.

    2014-10-15

    Neutrinoless double beta decay (0νββ) is one of the most sensitive probes for physics beyond the Standard Model, providing unique information on the nature of neutrinos. In this paper we review the status and outlook for bolometric 0νββ decay searches. We summarize recent advances in background suppression demonstrated using bolometers with simultaneous readout of heat and light signals. We simulate several configurations of a future CUORE-like bolometer array which would utilize these improvements and present the sensitivity reach of a hypothetical next-generation bolometric0νββ experiment. We demonstrate that a bolometric experiment with the isotope mass of about 1 ton is capable of reaching the sensitivity to the effective Majorana neutrino mass (|mee|) of order 10-20 meV, thus completely exploring the so-called inverted neutrino mass hierarchy region. In conclusion, we highlight the main challenges and identify priorities for an R&D program addressing them.

  6. Sensitivity of the LUX detector to the possible neutrinoless double beta decay of 134Xe

    NASA Astrophysics Data System (ADS)

    Pease, Evan; The LUX Collaboration Collaboration

    2017-01-01

    The Large Underground Xenon (LUX) detector is a 370-kg liquid xenon (LXe) time-projection chamber designed primarily for the direct detection of weakly-interacting massive particles (WIMPs), a leading dark matter candidate. LUX operates on the 4850-foot level of the Sanford Underground Research Facility in Lead, SD. The unenriched xenon of LUX contains the natural 10.4% abundance of the isotope 134Xe, a candidate for the lepton-number-violating process of neutrinoless double beta (0 νββ) decay. If observed, this process would confirm the existence of massive Majorana neutrinos and would be a possible path to the measurement of neutrino mass and other studies of new weak-interaction physics. Given its xenon mass and the length of exposure for the LUX detector, there is an opportunity to improve upon the T1 / 2 > 5 . 8 ×1022 yr sensitivity of the 6.5-kg DAMA experiment (enriched to 17.1%134Xe) from 2002 (Bernabei, et al., Phys. Lett. B 527, 182-186, 2002.). Building upon previous LUX measurements of the energy resolution and signal yields up to 662 keV, this talk will go over the response of the LUX detector at 826 keV, the 134Xe Q-value, and the current status of the LUX 134Xe 0 νββ analysis.

  7. Neutron capture cross-section studies of Tellurium isotopes for neutrinoless double beta decay applications

    NASA Astrophysics Data System (ADS)

    Bhike, Megha; Tornow, Werner

    2014-09-01

    The CUORE detector at Gran Sasso, aimed at searching for neutrinoless double-beta decay of 130Te, employs an array of TeO2 bolometer modules. To understand and identify the contribution of muon and (α,n) induced neutrons to the CUORE background, fast neutron cature cross-section data of the tellurium isotopes 126Te, 128Te and 130Te have been measured with the activation method at eight different energies in the neutron energy range 0.5-7.5 MeV. Plastic pill boxes of diameter 1.6 cm and width 1 cm containing Te were irradiated with mono-energetic neutrons produced via the 3H(p,n)3He and 2H(d,n)3He reactions. The cross-sections were determined relative to the 197Au(n, γ)198Au and 115In(n,n')115m In standard cross sections. The activities of the products were measured using 60% lead-shielded HPGe detectors at TUNL's low background counting facility. The present results are compared with the evaluated data from TENDL-2012, ENDF/B-VII.1, JEFF-3.2 and JENDL-4.0, as well as with literature data.

  8. GraXe, graphene and xenon for neutrinoless double beta decay searches

    NASA Astrophysics Data System (ADS)

    Gómez-Cadenas, J. J.; Guinea, F.; Fogler, M. M.; Katsnelson, M. I.; Martín-Albo, J.; Monrabal, F.; Muñoz Vidal, J.

    2012-02-01

    We propose a new detector concept, GraXe (to be pronounced as grace), to search for neutrinoless double beta decay in 136XE. GraXe combines a popular detection medium in rare-event searches, liquid xenon, with a new, background-free material, graphene. In our baseline design of GraXe, a sphere made of graphene-coated titanium mesh and filled with liquid xenon (LXe) enriched in the 136XE isotope is immersed in a large volume of natural LXe instrumented with photodetectors. Liquid xenon is an excellent scintillator, reasonably transparent to its own light. Graphene is transparent over a large frequency range, and impermeable to the xenon. Event position could be deduced from the light pattern detected in the photosensors. External backgrounds would be shielded by the buffer of natural LXe, leaving the ultra-radiopure internal volume virtually free of background. Industrial graphene can be manufactured at a competitive cost to produce the sphere. Enriching xenon in the isotope 136XE is easy and relatively cheap, and there is already near one ton of enriched xenon available in the world (currently being used by the EXO, KamLAND-Zen and NEXT experiments). All the cryogenic know-how is readily available from the numerous experiments using liquid xenon. An experiment using the GraXe concept appears realistic and affordable in a short time scale, and its physics potential is enormous.

  9. Dilepton bounds on left-right symmetry at the LHC run II and neutrinoless double beta decay

    NASA Astrophysics Data System (ADS)

    Lindner, Manfred; Queiroz, Farinaldo S.; Rodejohann, Werner

    2016-11-01

    In the light of the new 13 TeV dilepton data set with 3.2 fb-1 integrated luminosity from the ATLAS Collaboration, we derive limits on the Z‧ mass in the context of left-right symmetric models and exploit the complementarity with dijet and lljj data, as well as neutrinoless double beta decay. We keep the ratio of the left- and right-handed gauge coupling free in order to take into account different patterns of left-right symmetry breaking. By combining the dielectron and dimuon data we can exclude Z‧ masses below 3 TeV for gR =gL, and for gR ∼ 1 we rule out masses up to ∼ 4 TeV. Those comprise the strongest direct bounds on the Z‧ mass from left-right models up to date. We show that in the usual plane of right-handed neutrino and charged gauge boson mass, dilepton data can probe a region of parameter space inaccessible to neutrinoless double beta decay and lljj studies. Lastly, through the mass relation between WR and Z‧ we present an indirect bound on the lifetime of neutrinoless double beta decay using dilepton data. Our results prove that the often ignored dilepton data in the context of left-right models actually provide important complementary limits.

  10. Purifications of calcium carbonate and molybdenum oxide powders for neutrinoless double beta decay experiment, AMoRE

    SciTech Connect

    Park, HyangKyu

    2015-08-17

    The AMoRE (Advanced Mo based Rare process Experiment) collaboration is going to use calcium molybdate crystals to search for neutrinoless double beta decay of {sup 100}Mo isotope. In order to make the crystal, we use calcium carbonate and molybdenum oxide powders as raw materials. Therefore it is highly necessary to reduce potential sources for radioactive backgrounds such as U and Th in the powders. In this talk, we will present our studies for purification of calcium carbonate and molybdenum oxide powders.

  11. CANDLES project for the study of neutrino-less double beta decay of 48Ca

    NASA Astrophysics Data System (ADS)

    Yoshida, Sei

    2014-09-01

    There is, presently, strong evidence that neutrinos undergo flavor oscillations,and hence must have finite masses. Neutrino-less double beta (0 νββ) decay measurement offers a realistic opportunity to establish the Majorana nature of neutrinos and gives the absolute scale of the effective neutrino mass. CANDLES is the project to search for 0 νββ decay of 48Ca. A distinctive characteristic of 48Ca is the highest Q value (4.3 MeV) among 0 νββ isotopes. Therefore it enables us to measure 0 νββ decay signals in background free contribution. The CANDLES system consists of undoped CaF2 scintillators (CaF2),liquid scintillator (LS), and large photomultiplier tubes (PMTs). A large number of CaF2 crystals in the form of 10 cm cubes are immersed in the LS. Scintillating CaF2 crystals work as an active source detector for 0 νββ decay of 48Ca, together with LS as a multi-purpose detector component to both reject backgrounds and to propagate scintillation photons. PMTs are placed around the LS vessel to detect photons from both scintillators. The simple design concept of CANDLES enables us to increase the 48Ca source amount. 48Ca enrichment is also effective for the high sensitive measurement, because natural abundance of 48Ca is very low (0.19%). We have studied 48Ca enrichment and succeeded in obtaining enriched 48Ca although it is a small amount. Now we have developed the CANDLES III system, which contained with 300kg CaF2 crystals without enrichment, at the Kamioka underground laboratory. New light collection system was installed in 2012, and accordingly photo-coverage has been enlarged by about 80%. Further improvement will be expected in 2014 by installing a detector cooling system in order to increase light emission from CaF2 crystals. The detail of the latest CANDLES III (U.G.) system and its performance will be presented. Recently, we found that gamma rays from neutron captures on materials surrounding detector could be dominant background. These

  12. Short-baseline electron neutrino disappearance, tritium beta decay, and neutrinoless double-beta decay

    SciTech Connect

    Giunti, Carlo; Laveder, Marco

    2010-09-01

    We consider the interpretation of the MiniBooNE low-energy anomaly and the gallium radioactive source experiments anomaly in terms of short-baseline electron neutrino disappearance in the framework of 3+1 four-neutrino mixing schemes. The separate fits of MiniBooNE and gallium data are highly compatible, with close best-fit values of the effective oscillation parameters {Delta}m{sup 2} and sin{sup 2}2{theta}. The combined fit gives {Delta}m{sup 2}(greater-or-similar sign)0.1 eV{sup 2} and 0.11(less-or-similar sign)sin{sup 2}2{theta}(less-or-similar sign)0.48 at 2{sigma}. We consider also the data of the Bugey and Chooz reactor antineutrino oscillation experiments and the limits on the effective electron antineutrino mass in {beta} decay obtained in the Mainz and Troitsk tritium experiments. The fit of the data of these experiments limits the value of sin{sup 2}2{theta} below 0.10 at 2{sigma}. Considering the tension between the neutrino MiniBooNE and gallium data and the antineutrino reactor and tritium data as a statistical fluctuation, we perform a combined fit which gives {Delta}m{sup 2}{approx_equal}2 eV and 0.01(less-or-similar sign)sin{sup 2}2{theta}(less-or-similar sign)0.13 at 2{sigma}. Assuming a hierarchy of masses m{sub 1}, m{sub 2}, m{sub 3}<neutrinoless double-{beta} decay are, respectively, between about 0.06 and 0.49 and between about 0.003 and 0.07 eV at 2{sigma}. We also consider the possibility of reconciling the tension between the neutrino MiniBooNE and gallium data and the antineutrino reactor and tritium data with different mixings in the neutrino and antineutrino sectors. We find a 2.6{sigma} indication of a mixing angle asymmetry.

  13. Nd loaded liquid scintillator to search for 150Nd neutrinoless double beta decay

    NASA Astrophysics Data System (ADS)

    Barabanov, I.; Bezrukov, L.; Cattadori, C.; Danilov, N.; di Vacri, A.; Ianni, A.; Nisi, S.; Ortica, F.; Romani, A.; Salvo, C.; Smirnov, O.; Yanovich, E.

    2008-11-01

    The 150Nd is considered one of the most attractive candidate for searching neutrinoless double beta (0νββ-) decay, thanks to its high Q-value (3.367 MeV), that makes the external background issue less significative respect to other isotopes, and favorable computed matrix elements. The isotopic abundance of this isotope in natural neodimium is only 5.6% and up to now, it has been investigated only in low mass experiments. The next step is to increase the sensitivity of the experiments using larger mass of neodymium (10 ton-1 kton). This could be possible with a Nd loaded liquid scintillator (LS). At the Gran Sasso National Laboratory (LNGS), a joint INFN (Istituto Nazionale di Fisica Nucleare) and INR (Institute for Nuclear Research of Moscow) working group has been carrying out since 2001 an R&D activity aiming to develop organic liquid scintillators (LS) doped with metals. The achieved know-how and the satisfactory results obtained both with In and Gd allowed to face the development and production of Nd doped LS. The development of metal doped LS is challenging because the metal has to be embedded in a proper organic system that makes it soluble in an organic solvent minimizing the impact of the metal-organic compound on the optical and scintillation properties of the LS. A further challenge in the case of Nd is the presence of absorption bands of this element in the optical region with a transparent region around 400 nm, which is about at the maximum of the scintillator emission spectrum. A 2.5 1 Nd loaded LS has been produced diluting an originally developed Nd-Carboxylic (Nd-CBX) salt in pseudocumene (PC), the solvent of the Borexino liquid scintillator. The measured light yield, at [Nd] = 6.5 g/1 and [PPO] = 1.5 g/1, is ~ 75% of pure PC at the same fluor concentration (~ 10000 ph/MeV). The Nd doped LS has been tested in a 2 1 quartz cell (wrapped by VM2000 reflector film) having dimensions 5x5x100 cm3. The light propagates in the cell by total internal

  14. Neutrinoless double beta decay with Xe-136 in BOREXINO and the BOREXINO Counting Test Facility

    NASA Astrophysics Data System (ADS)

    Caccianiga, B.; Giammarchi, M. G.

    2000-08-01

    This article discusses the methods and sensitivity for a double beta decay experiment based on the Xe-136 candidate for BOREXINO or the BOREXINO Counting Test Facility. Different background assumptions and experimental configurations are studied, assuming a data obtaining period of one year. The related experimental problems are discussed, and summary tables containing the sensitivity estimates for the various configurations are presented.

  15. Dominance of Pion Exchange in {ital {ital R}}-Parity-Violating Supersymmetric Contributions to Neutrinoless Double Beta Decay

    SciTech Connect

    Faessler, A.; Kovalenko, S.; Simkovic, F.; Schwieger, J.; Kovalenko, S.; Simkovic, F.; Simkovic, F.

    1997-01-01

    We present a new contribution of the R-parity-violating (R/{sub p}) supersymmetry (SUSY) to neutrinoless double beta decay (0{nu}{beta}{beta}) via the pion exchange between decaying neutrons. The pion coupling to the final state electrons is induced by the R/{sub p} SUSY interactions. We have found this pion-exchange mechanism to dominate over the conventional two-nucleon one. The latter corresponds to direct interaction between quarks from two decaying neutrons without any light hadronic mediator like {pi} meson. The constraints on the certain R/{sub p} SUSY parameters are extracted from the current experimental 0{nu}{beta}{beta}-decay half-life limit. These constraints are significantly stronger than those previously known or expected from the ongoing accelerator experiments. {copyright} {ital 1997} {ital The American Physical Society}

  16. Extending two Higgs doublet models for two-loop neutrino mass generation and one-loop neutrinoless double beta decay

    NASA Astrophysics Data System (ADS)

    Liu, Zhen; Gu, Pei-Hong

    2017-02-01

    We extend some two Higgs doublet models, where the Yukawa couplings for the charged fermion mass generation only involve one Higgs doublet, by two singlet scalars respectively carrying a singly electric charge and a doubly electric charge. The doublet and singlet scalars together can mediate a two-loop diagram to generate a tiny Majorana mass matrix of the standard model neutrinos. Remarkably, the structure of the neutrino mass matrix is fully determined by the symmetric Yukawa couplings of the doubly charged scalar to the right-handed leptons. Meanwhile, a one-loop induced neutrinoless double beta decay can arrive at a testable level even if the electron neutrino has an extremely small Majorana mass. We also study other experimental constraints and implications including some rare processes and Higgs phenomenology.

  17. Five Sample Proposals for Next Generation Neutrinoless Double-Beta Decay Experiments

    NASA Astrophysics Data System (ADS)

    Avignone, F. T., III; King, G. S., III

    2005-06-01

    Five next generation zero-neutrino double-beta decay experimental proposals are discussed. They propose to utilize cryogenic, ionization, time-projection chamber, and tracking chamber techniques. The representative experiments are: CUORE/CUORICINO, EXO, Majorana, MOON, and NEMO. We make no claim that this selection of experiments is the best or in any way a complete listing. It is limited by the available space.

  18. The nature of massive neutrinos and multiple mechanisms in neutrinoless double-beta decay

    NASA Astrophysics Data System (ADS)

    Meroni, Aurora

    2015-11-01

    Determining the nature -Dirac or Majorana- of massive neutrinos is one of the most pressing and challenging problems in the field of neutrino physics. We discuss how one can possibly extract information on the couplings, if any, which might be involved in (ββ)_{0ν}-decay using a multi-isotope approach. We investigate as well the potential of combining data on the half-lives of nuclides with largely different Nuclear Matrix Elements such as 136Xe and of one or more of the four nuclei 76Ge, 82Se, 100Mo and 130Te, for discriminating between different pairs of noninterfering or interfering mechanisms of (ββ)_{0ν}-decay. The case studies do not extend to the evaluation of the theoretical uncertainties of the results, due to the nuclear matrix elements calculations and other causes.

  19. Searching for Neutrinoless Double-Beta Decay of 130 Te with CUORE

    DOE PAGES

    Artusa, D. R.; Avignone, F. T.; Azzolini, O.; ...

    2015-01-01

    Neumore » trinoless double-beta (0 ν β β ) decay is a hypothesized lepton-number-violating process that offers the only known means of asserting the possible Majorana nature of neutrino mass. The Cryogenic Underground Observatory for Rare Events (CUORE) is an upcoming experiment designed to search for 0 ν β β decay of 130 Te using an array of 988 TeO 2 crystal bolometers operated at 10 mK. The detector will contain 206 kg of 130 Te and have an average energy resolution of 5 keV; the projected 0 ν β β decay half-life sensitivity after five years of livetime is 1.6 × 10 26  y at 1 σ (9.5 × 10 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). In this paper, we review the experimental techniques used in CUORE as well as its current status and anticipated physics reach.« less

  20. Scintillating bolometric technique for the neutrino-less double beta decay search: The LUCIFER/CUPID-0 experiment

    NASA Astrophysics Data System (ADS)

    Casali, N.; Artusa, D. R.; Bellini, F.; Biassoni, M.; Brofferio, C.; Bucci, C.; Camacho, A.; Capelli, S.; Cardani, L.; Carniti, P.; Cassina, L.; Clemenza, M.; Cremonesi, O.; Cruciani, A.; D'Addabbo, A.; Dafinei, I.; Domizio, S. Di; Vacri, M. L. di; Ferroni, F.; Gironi, L.; Gotti, C.; Keppel, G.; Maino, M.; Martinez, M.; Morganti, S.; Nagorny, S.; Orlandi, D.; Pagnanini, L.; Pallavicini, M.; Palmieri, V.; Pattavina, L.; Pavan, M.; Pessina, G.; Pettinacci, V.; Pozzi, S.; Pirro, S.; Previtali, E.; Puiu, A.; Rusconi, C.; Schäffner, K.; Tomei, C.; Vignati, M.

    2017-02-01

    CUPID is a proposed future tonne-scale bolometric neutrino-less double beta decay (0 νββ) experiment to probe the Majorana nature of neutrinos and discover lepton number violation in the so-called inverted hierarchy region of the neutrino mass. In order to improve the sensitivity with respect to the current bolometric experiments, the source mass must be increased and the backgrounds in the region of interest must be dramatically reduced. The background suppression can be achieved discriminating β / γ against α events by means of the different light yield produced in the interactions within a scintillating bolometer. The increase in the number of 0 νββ emitters demands for crystals grown with enriched material. LUCIFER/CUPID-0, the first demonstrator of CUPID, aims at running the first array of enriched scintillating Zn82Se bolometers (total mass of about 7 kg of 82Se) with a background level as low as 10-3 counts/(keV kg y) in the energy region of interest. We present the results of the first measurement performed on three Zn82Se enriched scintillating bolometers operated deep underground in the Hall C of the Laboratori Nazionali del Gran Sasso.

  1. LUMINEU: a search for neutrinoless double beta decay based on ZnMoO4 scintillating bolometers

    NASA Astrophysics Data System (ADS)

    Armengaud, E.; Arnaud, Q.; Augier, C.; Benoît, A.; Benoît, A.; Boiko, L. Bergé S.; Bergmann, T.; Blümer, J.; Broniatowski, A.; Brudanin, V.; Camus, P.; Cazes, A.; Chapellier, M.; Charlieux, F.; Chernyak, D. M.; Coron, N.; Coulter, P.; Danevich, F. A.; de Boissiére, T.; Decourt, R.; De Jesus, M.; Devoyon, L.; Drillien, A.-A.; Dumoulin, L.; Eitel, K.; Enss, C.; Filosofov, D.; Fleischmann, A.; Foerster, N.; Fourches, N.; Gascon, J.; Gastaldo, L.; Gerbier, G.; Giuliani, A.; Gray, D.; Gros, M.; Hehn, L.; Henry, S.; Hervé, S.; Heuermann, G.; Humbert, V.; Ivanov, I. M.; Juillard, A.; Kéfélian, C.; Kleifges, M.; Kluck, H.; Kobychev, V. V.; Koskas, F.; Kozlov, V.; Kraus, H.; Kudryavtsev, V. A.; Le Sueur, H.; Loidl, M.; Magnier, P.; Makarov, E. P.; Mancuso, M.; de Marcillac, P.; Marnieros, S.; Marrache-Kikuchi, C.; Menshikov, A.; Nasonov, S. G.; Navick, X.-F.; Nones, C.; Olivieri, E.; Pari, P.; Paul, B.; Penichot, Y.; Pessina, G.; Piro, M. C.; Plantevin, O.; Poda, D. V.; Redon, T.; Robinson, M.; Rodrigues, M.; Rozov, S.; Sanglard, V.; Schmidt, B.; Scorza, S.; Shlegel, V. N.; Siebenborn, B.; Strazzer, O.; Tcherniakhovski, D.; Tenconi, M.; Torres, L.; Tretyak, V. I.; Vagneron, L.; Vasiliev, Ya V.; Velazquez, M.; Viraphong, O.; Walker, R. J.; Weber, M.; Yakushev, E.; Zhang, X.; Zhdankov, V. N.

    2016-05-01

    The LUMINEU is designed to investigate the possibility to search for neutrinoless double beta decay in 100 Mo by means of a large array of scintillating bolometers based on ZnMoO4 crystals enriched in 100 Mo. High energy resolution and relatively fast detectors, which are able to measure both the light and the heat generated upon the interaction of a particle in a crystal, are very promising for the recognition and rejection of background events. We present the LUMINEU concepts and the experimental results achieved aboveground and underground with large-mass natural and enriched crystals. The measured energy resolution, the α/β discrimination power and the radioactive internal contamination are all within the specifications for the projected final LUMINEU sensitivity. Simulations and preliminary results confirm that the LUMINEU technology can reach zero background in the region of interest (around 3 MeV) with exposures of the order of hundreds kgxyears, setting the bases for a next generation 0v2β decay experiment capable to explore the inverted hierarchy region of the neutrino mass pattern.

  2. Inelastic neutron scattering studies of Ge-76 and Se-76: relevance to neutrinoless double-beta decay

    SciTech Connect

    Crider, Ben; Peters, Erin; Ross, T.J.; McEllistrem, M; Prados-Estevez, F.; Allmond, James M; Vanhoy, J.R.; Yates, S.W.

    2015-01-01

    Inelastic neutron scattering measurements were performed at the University of Kentucky Accelerator Laboratory on enriched Ge-76 and Se-76 scattering samples. From measurements at incident neutron energies from 2.0 to 4.0 MeV, many new levels were identified and characterized in each nucleus; level lifetimes, transition probabilities, multipole mixing ratios, and other properties were determined. In addition, gamma-ray cross sections for the Ge-76(n,n'gamma) reaction were measured at neutron energies up to 5.0 MeV, with the goal of determining the cross sections of gamma rays in 2040-keV region, which corresponds to the region of interest in the neutrinoless double beta decay of Ge-76. Gamma rays from the three strongest branches from the 3952-keV level were observed, but the previously reported 2041-keV gamma ray was not. Population cross sections across the range of incident neutron energies were determined for the 3952-keV level, resulting in a cross section of similar to 0.1 mb for the 2041-keV branch using the previously determined branching ratios. Beyond this, the data from these experiments indicate that previously unreported gamma rays from levels in Ge-76 can be found in the 2039-keV region.

  3. Deformed shell model results for neutrinoless positron double beta decay of nuclei in the A = 60-90 region

    NASA Astrophysics Data System (ADS)

    Sahu, R.; Srivastava, P. C.; Kota, V. K. B.

    2013-09-01

    Nuclear transition matrix elements (NTME) for neutrinoless positron double beta decay (0νβ+β+ and 0νβ+EC) of 64Zn, 74Se, 78Kr and 84Sr nuclei, which are in the A = 60-90 region, are calculated within the framework of the deformed shell model (DSM) based on Hartree-Fock states. For 64Zn, GXPF1A interaction in 1f7/2, 2p3/2, 1f5/2 and 2p1/2 space with 40Ca as the core is employed. Similarly for 74Se, 78Kr and 84Sr nuclei, 56Ni is taken as the inert core employing a modified Kuo interaction in 2p3/2, 1f5/2, 2p1/2 and 1g9/2 space. After ensuring that the DSM gives a good description of the spectroscopic properties of low-lying levels in the four nuclei considered, the NTME are calculated. The half-lives deduced with these NTME, assuming the neutrino mass is 1 eV, are smallest for 78Kr with the half-life for β+EC decay being ˜1027 yr. For all others, the half-lives are in the range of ˜1028-1029 yr.

  4. Neutron-induced Backgrounds in 134Xe for Large-Scale Neutrinoless Double-Beta Decay Experiments

    NASA Astrophysics Data System (ADS)

    Moriguchi, Nina; Kidd, Mary; Tornow, Werner

    2016-09-01

    136Xe is used in large neutrinoless double-beta (0 νββ) decay experiments, such as KamLAND- Zen and EXO 200. Though highly purified, 136Xe still contains a significant amount of 134Xe. Recently, a new nuclear energy level was found in 134Xe. If 134Xe decays from this proposed excited state, it will emit a 2485.7 keV gamma ray. Because this energy lies near the region of interest of 136Xe νββ decay experiments (Q value 2457.8 keV), it could make a significant contribution to the background. A purified gaseous sample of 134Xe will be irradiated with neutrons of an incident energy of 4.0 MeV at Triangle Universities Nuclear Laboratory and monitored with high-purity germanium detectors. The spectra obtained from these detectors will be analyzed for the presence of the 2581 keV gamma ray. We will report on the status of this experiment. Future plans include expanding this measurement to higher initial neutron energies. Tennesse Tech University CISE Grant program.

  5. Search for neutrinoless double-beta decay of Mo 100 with the NEMO-3 detector

    SciTech Connect

    John D. Baker; A. J. Caffrey

    2014-06-01

    We report the results of a search for the neutrinoless double-ß decay (0?ßß ) of Mo 100 , using the NEMO-3 detector to reconstruct the full topology of the final state events. With an exposure of 34.7??kg·y , no evidence for the 0?ßß signal has been found, yielding a limit for the light Majorana neutrino mass mechanism of T 1/2 (0?ßß)>1.1×10 24 years (90% C.L.) once both statistical and systematic uncertainties are taken into account. Depending on the nuclear matrix elements this corresponds to an upper limit on the Majorana effective neutrino mass of ?m ? ?<0.3–0.9??eV (90% C.L.). Constraints on other lepton number violating mechanisms of 0?ßß decays are also given. Searching for high-energy double electron events in all suitable sources of the detector, no event in the energy region [3.2–10] MeV is observed for an exposure of 47??kg·y .

  6. Short-baseline electron neutrino disappearance, tritium beta decay, and neutrinoless double-beta decay

    NASA Astrophysics Data System (ADS)

    Giunti, Carlo; Laveder, Marco

    2010-09-01

    We consider the interpretation of the MiniBooNE low-energy anomaly and the gallium radioactive source experiments anomaly in terms of short-baseline electron neutrino disappearance in the framework of 3+1 four-neutrino mixing schemes. The separate fits of MiniBooNE and gallium data are highly compatible, with close best-fit values of the effective oscillation parameters Δm2 and sin⁡22ϑ. The combined fit gives Δm2≳0.1eV2 and 0.11≲sin⁡22ϑ≲0.48 at 2σ. We consider also the data of the Bugey and Chooz reactor antineutrino oscillation experiments and the limits on the effective electron antineutrino mass in β decay obtained in the Mainz and Troitsk tritium experiments. The fit of the data of these experiments limits the value of sin⁡22ϑ below 0.10 at 2σ. Considering the tension between the neutrino MiniBooNE and gallium data and the antineutrino reactor and tritium data as a statistical fluctuation, we perform a combined fit which gives Δm2≃2eV and 0.01≲sin⁡22ϑ≲0.13 at 2σ. Assuming a hierarchy of masses m1, m2, m3≪m4, the predicted contributions of m4 to the effective neutrino masses in β decay and neutrinoless double-β decay are, respectively, between about 0.06 and 0.49 and between about 0.003 and 0.07 eV at 2σ. We also consider the possibility of reconciling the tension between the neutrino MiniBooNE and gallium data and the antineutrino reactor and tritium data with different mixings in the neutrino and antineutrino sectors. We find a 2.6σ indication of a mixing angle asymmetry.

  7. Characterization of Nuclear Recoils in High Pressure Xenon Gas: Towards a Simultaneous Search for WIMP Dark Matter and Neutrinoless Double Beta Decay

    DOE PAGES

    Renner, J.; Gehman, V. M.; Goldschmidt, A.; ...

    2015-03-24

    Xenon has recently been the medium of choice in several large scale detectors searching for WIMP dark matter and neutrinoless double beta decay. Though present-day large scale experiments use liquid xenon, the gas phase offers advantages favorable to both types of searches such as improved intrinsic energy resolution and fewer fluctuations in the partition of deposited energy between scintillation and ionization channels. We recently constructed a high pressure xenon gas TPC as a prototype for the NEXT (Neutrino Experiment with a Xenon TPC) neutrinoless double beta decay experiment and have demonstrated the feasibility of 0.5% FWHM energy resolution at themore » 136Xe double beta Q-value with 3-D tracking capabilities. We now present results from this prototype on the simultaneous observation of scintillation and ionization produced by nuclear recoils at approximately 14 bar pressure. The recoils were produced by neutrons of approximately 2-6 MeV emitted from a radioisotope plutonium-beryllium source, and primary scintillation (S1) and electroluminescent photons produced by ionization (S2) were observed. We discuss the potential of gaseous xenon to distinguish between electron and nuclear recoils through the ratio of these two signals S2/S1. From these results combined with the possibility of using columnar recombination to sense nuclear recoil directionality at high pressures we envision a dual-purpose, ton-scale gaseous xenon detector capable of a combined search for WIMP dark matter and neutrinoless double beta decay. This work has been performed within the context of the NEXT collaboration.« less

  8. Characterization of Nuclear Recoils in High Pressure Xenon Gas: Towards a Simultaneous Search for WIMP Dark Matter and Neutrinoless Double Beta Decay

    SciTech Connect

    Renner, J.; Gehman, V. M.; Goldschmidt, A.; Oliveira, C. A.B.; Nygren, D.

    2015-03-24

    Xenon has recently been the medium of choice in several large scale detectors searching for WIMP dark matter and neutrinoless double beta decay. Though present-day large scale experiments use liquid xenon, the gas phase offers advantages favorable to both types of searches such as improved intrinsic energy resolution and fewer fluctuations in the partition of deposited energy between scintillation and ionization channels. We recently constructed a high pressure xenon gas TPC as a prototype for the NEXT (Neutrino Experiment with a Xenon TPC) neutrinoless double beta decay experiment and have demonstrated the feasibility of 0.5% FWHM energy resolution at the 136Xe double beta Q-value with 3-D tracking capabilities. We now present results from this prototype on the simultaneous observation of scintillation and ionization produced by nuclear recoils at approximately 14 bar pressure. The recoils were produced by neutrons of approximately 2-6 MeV emitted from a radioisotope plutonium-beryllium source, and primary scintillation (S1) and electroluminescent photons produced by ionization (S2) were observed. We discuss the potential of gaseous xenon to distinguish between electron and nuclear recoils through the ratio of these two signals S2/S1. From these results combined with the possibility of using columnar recombination to sense nuclear recoil directionality at high pressures we envision a dual-purpose, ton-scale gaseous xenon detector capable of a combined search for WIMP dark matter and neutrinoless double beta decay. This work has been performed within the context of the NEXT collaboration.

  9. Improved background rejection in neutrinoless double beta decay experiments using a magnetic field in a high pressure xenon TPC

    NASA Astrophysics Data System (ADS)

    Renner, J.; Cervera, A.; Hernando, J. A.; Imzaylov, A.; Monrabal, F.; Muñoz, J.; Nygren, D.; Gomez-Cadenas, J. J.

    2015-12-01

    We demonstrate that the application of an external magnetic field could lead to an improved background rejection in neutrinoless double-beta (0νββ) decay experiments using a high-pressure xenon (HPXe) TPC. HPXe chambers are capable of imaging electron tracks, a feature that enhances the separation between signal events (the two electrons emitted in the 0νββ decay of 136Xe) and background events, arising chiefly from single electrons of kinetic energy compatible with the end-point of the 0νββ decay (0Qββ). Applying an external magnetic field of sufficiently high intensity (in the range of 0.5-1 Tesla for operating pressures in the range of 5-15 atmospheres) causes the electrons to produce helical tracks. Assuming the tracks can be properly reconstructed, the sign of the curvature can be determined at several points along these tracks, and such information can be used to separate signal (0νββ) events containing two electrons producing a track with two different directions of curvature from background (single-electron) events producing a track that should spiral in a single direction. Due to electron multiple scattering, this strategy is not perfectly efficient on an event-by-event basis, but a statistical estimator can be constructed which can be used to reject background events by one order of magnitude at a moderate cost (about 30%) in signal efficiency. Combining this estimator with the excellent energy resolution and topological signature identification characteristic of the HPXe TPC, it is possible to reach a background rate of less than one count per ton-year of exposure. Such a low background rate is an essential feature of the next generation of 0νββ experiments, aiming to fully explore the inverse hierarchy of neutrino masses.

  10. Predictions for the Majorana CP violation phases in the neutrino mixing matrix and neutrinoless double beta decay

    NASA Astrophysics Data System (ADS)

    Girardi, I.; Petcov, S. T.; Titov, A. V.

    2016-10-01

    We obtain predictions for the Majorana phases α21 / 2 and α31 / 2 of the 3 × 3 unitary neutrino mixing matrix U = Ue† Uν, Ue and Uν being the 3 × 3 unitary matrices resulting from the diagonalisation of the charged lepton and neutrino Majorana mass matrices, respectively. We focus on forms of Ue and Uν permitting to express α21 / 2 and α31 / 2 in terms of the Dirac phase δ and the three neutrino mixing angles of the standard parametrisation of U, and the angles and the two Majorana-like phases ξ21 / 2 and ξ31 / 2 present, in general, in Uν. The concrete forms of Uν considered are fixed by, or associated with, symmetries (tri-bimaximal, bimaximal, etc.), so that the angles in Uν are fixed. For each of these forms and forms of Ue that allow to reproduce the measured values of the three neutrino mixing angles θ12, θ23 and θ13, we derive predictions for phase differences (α21 / 2 -ξ21 / 2), (α31 / 2 -ξ31 / 2), etc., which are completely determined by the values of the mixing angles. We show that the requirement of generalised CP invariance of the neutrino Majorana mass term implies ξ21 = 0 or π and ξ31 = 0 or π. For these values of ξ21 and ξ31 and the best fit values of θ12, θ23 and θ13, we present predictions for the effective Majorana mass in neutrinoless double beta decay for both neutrino mass spectra with normal and inverted ordering.

  11. Discovery potential of xenon-based neutrinoless double beta decay experiments in light of small angular scale CMB observations

    SciTech Connect

    Gómez-Cadenas, J.J.; Martín-Albo, J.; Vidal, J. Muñoz; Peña-Garay, C. E-mail: jmalbos@ific.uv.es E-mail: penya@ific.uv.es

    2013-03-01

    The South Pole Telescope (SPT) has probed an expanded angular range of the CMB temperature power spectrum. Their recent analysis of the latest cosmological data prefers nonzero neutrino masses, with Σm{sub ν} = (0.32±0.11) eV. This result, if confirmed by the upcoming Planck data, has deep implications on the discovery of the nature of neutrinos. In particular, the values of the effective neutrino mass m{sub ββ} involved in neutrinoless double beta decay (ββ0ν) are severely constrained for both the direct and inverse hierarchy, making a discovery much more likely. In this paper, we focus in xenon-based ββ0ν experiments, on the double grounds of their good performance and the suitability of the technology to large-mass scaling. We show that the current generation, with effective masses in the range of 100 kg and conceivable exposures in the range of 500 kg·year, could already have a sizeable opportunity to observe ββ0ν events, and their combined discovery potential is quite large. The next generation, with an exposure in the range of 10 ton·year, would have a much more enhanced sensitivity, in particular due to the very low specific background that all the xenon technologies (liquid xenon, high-pressure xenon and xenon dissolved in liquid scintillator) can achieve. In addition, a high-pressure xenon gas TPC also features superb energy resolution. We show that such detector can fully explore the range of allowed effective Majorana masses, thus making a discovery very likely.

  12. Measurement of scintillation and ionization yield with high-pressure gaseous mixtures of Xe and TMA for improved neutrinoless double beta decay and dark matter searches

    NASA Astrophysics Data System (ADS)

    Nakajima, Y.; Goldschmidt, A.; Matis, H. S.; Miller, T.; Nygren, D. R.; Oliveira, C. A. B.; Renner, J.

    2016-03-01

    The gaseous Xenon(Xe) time projection chamber (TPC) is an attractive detector technique for neutrinoless double beta decay and WIMP dark matter searches. While it is less dense compared to Liquid Xe detectors, it has intrinsic advantages in tracking capability and better energy resolution. The performance of gaseous Xe can be further improved by molecular additives such as trimethylamine(TMA), which is expected to (1) cool down the ionization electrons, (2) convert Xe excitation energy to TMA ionizations through Penning transfer, and (3) produce scintillation and electroluminescence light in a more easily detectable wavelength (300 nm). In order to test the feasibility of the performance improvements with TMA, we made the first direct measurement of Penning and fluorescence transfer efficiency with gaseous mixtures of Xe and TMA. While we observed a Penning transfer efficiency up to ~35%, we found strong suppression of primary scintillation light with TMA. We also found that the primary scintillation light with Xe and TMA mixture can be well characterized by ~3% fluorescence transfer from Xe to TMA, with further suppression due to TMA self-quenching. No evidence of the scintillation light produced by recombination of TMA ions was found. This strong suppression of scintillation light makes dark matter searches quite challenging, while the possibility of improved neutrinoless double beta decay searches remains open. This work has been carried out within the context of the NEXT collaboration.

  13. Role of triaxiality in 76Ge and 76Se nuclei studied with Gogny energy density functionals

    NASA Astrophysics Data System (ADS)

    Rodríguez, Tomás R.

    2017-03-01

    The structure of the nuclei 76Ge and 76Se is studied with symmetry conserving configuration mixing methods based on the Gogny D1S interaction. These two nuclei are of key importance in the search for neutrinoless double-beta decay. The energy density functionals used here include symmetry restorations (particle number and angular momentum) and shape mixing within the generator coordinate method. The comparison with the experimental data shows a good qualitative agreement when triaxial shapes are included, revealing the important role played by this degree of freedom in these two nuclei.

  14. TeO[Formula: see text] bolometers with Cherenkov signal tagging: towards next-generation neutrinoless double-beta decay experiments.

    PubMed

    Casali, N; Vignati, M; Beeman, J W; Bellini, F; Cardani, L; Dafinei, I; Di Domizio, S; Ferroni, F; Gironi, L; Nagorny, S; Orio, F; Pattavina, L; Pessina, G; Piperno, G; Pirro, S; Rusconi, C; Schäffner, K; Tomei, C

    CUORE, an array of 988 TeO[Formula: see text] bolometers, is about to be one of the most sensitive experiments searching for neutrinoless double-beta decay. Its sensitivity could be further improved by removing the background from [Formula: see text] radioactivity. A few years ago it was pointed out that the signal from [Formula: see text]s can be tagged by detecting the emitted Cherenkov light, which is not produced by [Formula: see text]s. In this paper we confirm this possibility. For the first time we measured the Cherenkov light emitted by a CUORE crystal, and found it to be 100 eV at the [Formula: see text]-value of the decay. To completely reject the [Formula: see text] background, we compute that one needs light detectors with baseline noise below 20 eV RMS, a value which is 3-4 times smaller than the average noise of the bolometric light detectors we are using. We point out that an improved light detector technology must be developed to obtain TeO[Formula: see text] bolometric experiments able to probe the inverted hierarchy of neutrino masses.

  15. Charged lepton flavour violcxmation and neutrinoless double beta decay in left-right symmetric models with type I+II seesaw

    NASA Astrophysics Data System (ADS)

    Borah, Debasish; Dasgupta, Arnab

    2016-07-01

    We study the new physics contributions to neutrinoless double beta decay (0 νββ) half-life and lepton flavour violation (LFV) amplitude within the framework of the minimal left-right symmetric model (MLRSM). Considering all possible new physics contributions to 0 νββ and charged lepton flavour violation μ → eγ , μ → 3 e in MLRSM, we constrain the parameter space of the model from the requirement of satisfying existing experimental bounds. Assuming the breaking scale of the left-right symmetry to be O (1) TeV accessible at ongoing and near future collider experiments, we consider the most general type I+II seesaw mechanism for the origin of tiny neutrino masses. Choosing the relative contribution of the type II seesaw term allows us to calculate the right handed neutrino mass matrix as well as Dirac neutrino mass matrix as a function of the model parameters, required for the calculation of 0νββ and LFV amplitudes. We show that such a general type I+II seesaw structure results in more allowed parameter space compared to individual type I or type II seesaw cases considered in earlier works. In particular, we show that the doubly charged scalar masses M Δ are allowed to be smaller than the heaviest right handed neutrino mass M N from the present experimental bounds in these scenarios which is in contrast to earlier results with individual type I or type II seesaw showing M Δ > M N .

  16. Herman Feshbach Prize in Theoretical Nuclear Physics Xiangdong Ji, University of Maryland PandaX-III: high-pressure gas TPC for Xe136 neutrinoless double beta decay at CJPL

    NASA Astrophysics Data System (ADS)

    Ji, Xiangdong; PandaX-III Collaboration

    2016-03-01

    The PandaX-III in China's Jinping Underground Lab is a new neutrinoless double beta decay experiment using Xe136 high-pressure gas TPC. The first phase of the experiment uses a 4 m3 gas detector with symmetric Micromegas charge readout planes. The gas TPC allows full reconstruction of the event topology, capable of distinguishing the two electron events from gamma background with high confidence level. The energy resolution can reach about 3% FWHM at the beta decay Q-value. The detector construction and the experimental lab is currently under active development. In this talk, the current status and future plan are reported.

  17. Measurement of scintillation and ionization yield with high-pressure gaseous mixtures of Xe and TMA for improved neutrinoless double beta decay and dark matter searches

    NASA Astrophysics Data System (ADS)

    Nakajima, Y.; Goldschmidt, A.; Matis, H. S.; Nygren, D.; Oliveira, C.; Renner, J.

    2015-11-01

    Liquid Xe TPCs are among the most popular choices for double beta decay and WIMP dark matter searches. Gaseous Xe has intrinsic advantages when compared to Liquid Xe, specifically, tracking capability and better energy resolution for double beta decay searches. The performance of gaseous Xe can be further improved by molecular additives such as trimethylamine(TMA), which are expected to (1) cool down the ionization electrons, (2) convert Xe excitation energy to TMA ionizations through Penning transfer, and (3) produce scintillation and electroluminescence light in a more easily detectable wavelength (300 nm). These features may provide better tracking and energy resolution for double-beta decay searches. They are also expected to enhance columnar recombination for nuclear recoils, which can be used for searches for WIMP dark matter with directional sensitivity. We constructed a test ionization chamber and successfully measured scintillation and ionization yields at high precision with various Xe and TMA mixtures and pressures. We observed the Penning effect and an increase in recombination with the addition of TMA. However, many undesired features for dark matter searches, such as strong suppression of the scintillation light and no sign of recombination light, were also found. This work has been carried out within the context of the NEXT collaboration.

  18. Review of modern double beta decay experiments

    SciTech Connect

    Barabash, A. S.

    2015-10-28

    The review of modern experiments on search and studying of double beta decay processes is done. Results of the most sensitive current experiments are discussed. The main attention is paid to EXO-200, KamLAND-Zen, GERDA-I and CUORE-0 experiments. Modern values of T{sub 1/2}(2ν) and best present limits on neutrinoless double beta decay and double beta decay with Majoron emission are presented. Conservative limits on effective mass of a Majorana neutrino (〈m{sub ν}〉 < 0.46 eV) and a coupling constant of Majoron to neutrino (〈g{sub ee}〉 < 1.3 · 10{sup −5}) are obtained. Prospects of search for neutrinoless double beta decay in new experiments with sensitivity to 〈m{sub ν}〉 at the level of ∼ 0.01-0.1 eV are discussed.

  19. The cosmogenic induced background estimation for the MAJORANA DEMONSTRATOR enriched 76Ge

    NASA Astrophysics Data System (ADS)

    White, Brandon; Majorana Collaboration

    2016-03-01

    Neutrino-less double beta (0 νββ) decay experiments probe for such rare events that the suppression of backgrounds are major experimental concerns. Cosmogenic induced isotopes have the potential to be a major background for such experiments. For the MAJORANA DEMONSTRATOR Experiment 76Ge isotope is used as both detector and source. The isotope 68Ge is cosmogenically produced when the Ge is on the Earth's surface. The decay of this isotope can mimic events in the region of interest. The experiment is located at the 4850 foot level at the Sanford Underground Research Facility in Lead, South Dakota to suppress cosmogenic activation. In this talk I will present the calculations of cosmogenic background for the enriched 76Ge materials used in the MAJORANA DEMONSTRATOR HPGe detectors. The activation is determined by the surface exposure from the time of production, storage, and delivery of the enriched Ge detectors to the underground experimental site. This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics, the Particle Astrophysics and Nuclear Physics Programs of the National Science Foundation, and the Sanford Underground Research Faci.

  20. Double Beta Decay

    NASA Astrophysics Data System (ADS)

    Fiorini, Ettore

    2010-12-01

    Almost exactly seventy years ago and only one year before his tragic disappearance the ingenious idea of Ettore Majorana is becoming one of the most important step in the development of fundamental physics. The problem of the nature of the neutrino, namely if it is a massless Dirac particle different from its antineutrino or a Majorana particle with finite mass, is discussed. In fact the recent results showing the presence of neutrino oscillations clearly indicates that the difference between the squared mass of neutrinos of different flavours is finite. Neutrinoless double beta decay (DBD) is at present the most powerful tool to determine the effective value of the mass of a Majorana neutrino. The results already obtained in this lepton violating process will be reported and the two presently running DBD experiments briefly discussed. The future second generation experiments will be reviewed with special emphasis to those already at least partially approved. In conclusion the peculiar and interdisciplinary nature of these searches will be stressed in their exciting aim to discover if neutrino is indeed a Majorana particle.

  1. Characterization of the energy resolution and the tracking capabilities of a hybrid pixel detector with CdTe-sensor layer for a possible use in a neutrinoless double beta decay experiment

    NASA Astrophysics Data System (ADS)

    Filipenko, Mykhaylo; Gleixner, Thomas; Anton, Gisela; Durst, Jürgen; Michel, Thilo

    2013-04-01

    Many different experiments are being developed to explore the existence of the neutrinoless double beta decay (0 νββ) since it would imply fundamental consequences for particle physics. In this work we present results on the evaluation of Timepix detectors with cadmium-telluride sensor material to search for 0 νββ in 116Cd. This work was carried out with the COBRA collaboration and the Medipix collaboration. Due to the relatively small pixel dimension of 110×110×1000 μm3 the energy deposited by particles typically extends over several detector pixels leading to a track in the pixel matrix. We investigated the separation power regarding different event-types like α-particles, atmospheric muons, single electrons and electron-positron pairs produced at a single vertex. We achieved excellent classification power for α-particles and muons. In addition, we achieved good separation power between single electron and electron-positron pair production events. These separation abilities indicate a very good background reduction for the 0 νββ search. Further, in order to distinguish between 2 νββ and 0 νββ, the energy resolution is of particular importance. We carried out simulations which demonstrate that an energy resolution of 0.43 % is achievable at the Q-value for 0 νββ of 116Cd at 2.814 MeV. We measured an energy resolution of 1.6 % at a nominal energy of 1589 keV for electron-positron tracks which is about two times worse that predicted by our simulations. This deviation is probably due to the problem of detector calibration at energies above 122 keV which is discussed in this paper as well.

  2. /sup 76/Ge double beta decay experiment at Homestake

    SciTech Connect

    Brodzinski, R.L.; Brown, D.P.; Evans, J.C. Jr.; Hensley, W.K.; Reeves, J.H.; Wogman, N.A.; Avignone, F.T. III; Miley, H.S.

    1985-01-25

    An ultralow background intrinsic Ge detector has been developed over several generations of experiments. The radioactive background from construction materials has been reduced by more than two orders of magnitude. The sources of background in a standard commercial cryostat have been identified and eliminated. Data taken with this 135 cm/sup 3/ prototype installed in the Homestake Gold Mine are presented. A large (1440 cm/sup 3/) detector and data acquisition system now under construction are also described.

  3. /sup 76/Ge double beta decay experiment at Homestake

    SciTech Connect

    Brodzinski, R.L.; Brown, D.P.; Evans, J.C. Jr.; Hensley, W.K.; Reeves, J.H.; Wogman, N.A.; Avignone, F.T. III; Miley, H.S.

    1984-08-01

    An ultralow background intrinsic Ge detector has been developed over several generations of experiments. The radioactive background from construction materials has been reduced by more than two orders of magnitude. The sources of background in a standard commercial cryostat have been identified and eliminated. Data are presented taken with this 135 cm/sup 3/ prototype, installed in the Homestake Gold Mine. A large (1440 cm/sup 3/) detector and data acquisition system are under construction and are also described. 11 references, 4 tables, 2 figures.

  4. The double-beta decay: Theoretical challenges

    SciTech Connect

    Horoi, Mihai

    2012-11-20

    Neutrinoless double beta decay is a unique process that could reveal physics beyond the Standard Model of particle physics namely, if observed, it would prove that neutrinos are Majorana particles. In addition, it could provide information regarding the neutrino masses and their hierarchy, provided that reliable nuclear matrix elements can be obtained. The two neutrino double beta decay is an associate process that is allowed by the Standard Model, and it was observed for about ten nuclei. The present contribution gives a brief review of the theoretical challenges associated with these two process, emphasizing the reliable calculation of the associated nuclear matrix elements.

  5. Nuclear-Structure Data Relevant to Neutinoless-Double-Beta-Decay Matrix Elements

    NASA Astrophysics Data System (ADS)

    Kay, Benjamin

    2015-10-01

    An observation of neutrinoless double beta decay is one of the most exciting prospects in contemporary physics. It follows that calculations of the nuclear matrix elements for this process are of high priority. The change in the wave functions between the initial and final states of the neutrinoless-double-beta-decay candidates 76Ge-->76Se, 100Mo-->100Ru, 130Te-->130Xe, and 136Xe-->136Ba have been studied with transfer reactions. The data are focused on the change in the occupancies of the valence orbitals in the ground states as two neutrons decay into two protons. The results set a strict constraint on any theoretical calculations describing this rearrangement and thus on the magnitude of the nuclear matrix elements for this process, which currently exhibit uncertainties at the factor of 2-4 level. Prior to these measurements there were limited experimental data were available A = 76 and 100 systems, and very limited data for the A = 130 and 136 systems, in a large part due to the gaseous Xe isotopes involved. The uncertainties on most of these data are estimated to range from 0.1-0.3 nucleons. The program started with the A = 76 system, with subsequent calculations, modified to reproduce the experimental occupancies, exhibiting a significant reduction in the discrepancy between various models. New data are available for the A = 100 , 130, and 136 systems. I review the program, making detailed comparisons between the latest theoretical calculations and the experimental data where available. This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics, under Contract Number DE-AC02-06CH11357.

  6. The NEXT double beta decay experiment

    NASA Astrophysics Data System (ADS)

    Laing, A.; NEXT Collaboration

    2016-05-01

    NEXT (Neutrino Experiment with a Xenon TPC) is a neutrinoless double-beta (ββ0v) decay experiment at Laboratorio Subterraneo de Canfranc (LSC). It is an electroluminescent Time Projection Chamber filled with high pressure 136Xe gas with separated function capabilities for calorimetry and tracking. Energy resolution and background suppression are the two key features of any neutrinoless double beta decay experiment. NEXT has both good energy resolution (< 1% FWHM) and an extra handle for background identification provided by track reconstruction. We expect a background rate of 4 × 10-4 counts keV-1 kg-1 yr-1, and a sensitivity to the Majorana neutrino mass of between 80-160 meV (depending on NME) after a run of 3 effective years of the 100 kg scale NEXT-100 detector. The initial phase of NEXT-100, called NEW, is currently being commissioned at LSC. It will validate the NEXT background rate expectations and will make first measurements of the two neutrino ββ2v mode of 136Xe. Furthermore, the NEXT technique can be extrapolated to the tonne scale, thus allowing the full exploration of the inverted hierarchy of neutrino masses. These proceedings review NEXT R&D results, the status of detector commissioning at LSC and the NEXT physics case.

  7. Double-beta decay: Some recent results and developments

    NASA Astrophysics Data System (ADS)

    Avignone, F. T.

    A brief review and status of theoretical issues associated with double-beta decay (ββ-decay) is given. The final results of the measurement of 2ν ββ-decay of 100Mo to the first excited 0 + state in 100Ru are presented prior to publication. Corrections to the earlier PNL/USC/ITEP/YPI measurement of 2ν ββ-decay of 76Ge are also given prior to publication. Finally, a status report and first results of the phase-I of the International Germanium Experiment (IGEX) are presented.

  8. Searching for Double Beta Decay with the Enriched Xenon Observatory

    SciTech Connect

    Hall, C.; /SLAC

    2007-03-16

    The Enriched Xenon Observatory (EXO) Collaboration is building a series of experiments to search for the neutrinoless double beta decay of {sup 136}Xe. The first experiment, known as EXO-200, will utilize 200 kg of xenon enriched to 80% in the isotope of interest, making it the largest double beta decay experiment to date by one order of magnitude. This experiment is rapidly being constructed, and will begin data taking in 2007. The EXO collaboration is also developing a technique to identify on an event-by-event basis the daughter barium ion of the double beta decay. If successful, this method would eliminate all conventional radioactive backgrounds to the decay, resulting in an ideal experiment. We summarize here the current status of EXO-200 construction and the barium tag R&D program.

  9. A calorimetric search on double beta decay of 130Te

    NASA Astrophysics Data System (ADS)

    Arnaboldi, C.; Brofferio, C.; Bucci, C.; Capelli, S.; Cremonesi, O.; Fiorini, E.; Giuliani, A.; Nucciotti, A.; Pavan, M.; Pedretti, M.; Pessina, G.; Pirro, S.; Pobes, C.; Previtali, E.; Sisti, M.; Vanzini, M.

    2003-04-01

    We report on the final results of a series of experiments on double beta decay of 130Te carried out with an array of twenty cryogenic detectors. The set-up is made with crystals of TeO2 with a total mass of 6.8 kg, the largest operating one for a cryogenic experiment. Four crystals are made with isotopically enriched materials: two in 128Te and two others in 130Te. The remaining ones are made with natural tellurium, which contains 31.7% and 33.8% 128Te and 130Te, respectively. The array was run under a heavy shield in the Gran Sasso Underground Laboratory at a depth of about 3500 m.w.e. By recording the pulses of each detector in anticoincidence with the others a lower limit of 2.1×1023 years has been obtained at the 90% C.L. on the lifetime for neutrinoless double beta decay of 130Te. In terms of effective neutrino mass this leads to the most restrictive limit in direct experiments, after those obtained with Ge diodes. Limits on other lepton violating decays of 130Te and on the neutrinoless double beta decay of 128Te to the ground state of 128Xe are also reported and discussed. An indication is presented for the two neutrino double beta decay of 130Te. Some consequences of the present results in the interpretation of geochemical experiments are discussed.

  10. Double beta decay: Calorimeters

    NASA Astrophysics Data System (ADS)

    Brofferio, Chiara

    2008-11-01

    Calorimeters or, with a more specific definition, low temperature detectors, have been used by now for more than 15 years in Double Beta Decay (DBD) searches, with excellent results: they compete with Ge diodes for the rank of detectors with the highest sensitivity to the effective neutrino mass, which is defined as a linear combination of the neutrino mass eigenvalues. After a brief introduction to the argument, with some notes on DBD and on bolometers, an update on the now closed experiment CUORICINO and on its successor, CUORE, is given. The fundamental role of background is then revealed and commented, introducing in this way the importance of the specific experiment now under construction, CUORE-0, that will precede CUORE to help optimizing the struggle against surface background. The possible future of this technique is then commented, quoting important R&D studies that are going on, for active shielding bolometers and for scintillating bolometers coupled with light detecting bolometers.

  11. Gauge vectors and double beta decay

    NASA Astrophysics Data System (ADS)

    Fonseca, Renato M.; Hirsch, Martin

    2017-02-01

    We discuss contributions to neutrinoless double beta (0 ν β β ) decay involving vector bosons. The starting point is a list of all possible vector representations that may contribute to 0 ν β β decay via d =9 or d =11 operators at tree level. We then identify gauge groups which contain these vectors in the adjoint representation. Even though the complete list of vector fields that can contribute to 0 ν β β up to d =11 is large (a total of 46 vectors), only a few of them can be gauge bosons of phenomenologically realistic groups. These latter cases are discussed in some more detail, and lower (upper) limits on gauge boson masses (mixing angles) are derived from the absence of 0 ν β β decay.

  12. Double Beta Decay in Gauge Theories

    NASA Astrophysics Data System (ADS)

    Vergados, J. D.

    2002-09-01

    Neutrinoless double beta decay is a very important process both from the particle and nuclear physics point of view. From the elementary particle point of view it pops up in almost every model, giving rise among others to the following mechanisms: a) The traditional contributions like the light neutrino mass mechanism as well as the jL - jR leptonic interference (λ and η terms). b) The exotic R-parity violating supersymmetric (SUSY) contributions. From the nuclear physics point of view it is challenging, because: 1) The nuclei, which can undergo double beta decay, have complicated nuclear structure. 2) The energetically allowed transitions are suppressed (exhaust a small part of all the strength). 3) Since in some mechanisms the intermediate particles are very heavy one must cope with the short distance behavior of the transition operators. 4) The intermediate momenta involved are quite high and one has to consider momentum dependent terms of the nucleon current. Taking the above effects into account from the experimental limits on the interesting nuclei A = 76, 82, 96, 100, 116, 128, 130, 136 and 150, we have extracted new limits on the various lepton violating parameters. In particular we get a stringent limit on the R-parity violating parameter λ '111 < 4.0 × 10-4.

  13. Results of the double beta decay experiment NEMO-3

    SciTech Connect

    Tretyak, V. I.; Collaboration: NEMO-3 Collaboration

    2013-12-30

    The double beta decay experiment NEMO-3 has taken data from February 2003 to January 2011. The two-neutrino decay half lives were measured for seven different isotopes ({sup 100}Mo, {sup 82}Se, {sup 116}Cd, {sup 150}Nd, {sup 96}Zr, {sup 48}Ca and {sup 130}Te). No evidence for neutrinoless double beta decay is observed. The 0νββ half-life limits are found to be T{sub 1/2}{sup 0ν}({sup 100}Mo)>1.0×10{sup 24}yr(90%C.L.) and T{sub 1/2}{sup 0ν}({sup 82}Se)>3.2×10{sup 23}yr(90%C.L.)

  14. Spectroscopic Studies of Double Beta Decays and MOON

    NASA Astrophysics Data System (ADS)

    Ejiri, H.

    2007-10-01

    This is a brief review of future spectroscopic experiments of neutrino-less double beta decays (0νββ) and the MOON (Mo Observatory Of Neutrinos) project. Spectroscopic 0νββ experiments of MOON, SuperNEMO and DCBA are planned to study Majorana masses in the quasi-degenerate (QD) and inverted mass hierarchy (IH) regions. MOON aims at 0νββ studies with the ν-mass sensitivities of 100-30 meV by means of a super ensemble of multi-layer modules, each being consist of a scintillator plate, two tracking detector planes and a thin ββ source film.

  15. Double Beta Decays and Neutrinos - Experiments and MOON -

    NASA Astrophysics Data System (ADS)

    Ejiri, H.

    2008-01-01

    This is a brief review of the present and future experiments of neutrino-less double beta decays (0νββ) and the MOON (Mo Observatory Of Neutrinos) project. High sensitivity 0νββ experiments are unique and realistic probes for studying the Majorana nature of neutrinos and the absolute mass scale as suggested by neutrino oscillation experiments. MOON aims at spectroscopic 0νββ studies with the ν-mass sensitivity of 100-30 meV by means of a super ensemble of multilayer modules of scintillator plates and tracking detector planes.

  16. A Search for Lorentz-Violation in Double Beta Decay with EXO-200

    NASA Astrophysics Data System (ADS)

    Johnson, Tessa; EXO-200 Collaboration

    2015-10-01

    The Standard-Model Extension (SME) framework assumes Lorentz-violation at the Planck scale, a result of certain theories uniting quantum mechanics to General Relativity. Lorentz-violating operators are added to the current Standard Model, potentially producing effects that could be observed on a macroscopic scale, for instance altering the standard spectrum of double beta decay. The EXO-200 experiment uses 175 kg of enriched liquid xenon to search for neutrinoless double beta decay in 136Xe, and the low background and high precision of the experiment create a good platform to search for other phenomena in double beta decay. The results of a search for deviations to the two-neutrino double beta decay spectrum of 136Xe that would indicate neutrino coupling to a Lorentz-violating operator in the SME are presented.

  17. Tracking electrons from double beta decay - How far can you push the TPC?

    NASA Astrophysics Data System (ADS)

    Moe, M. K.; Nelson, M. A.; Vient, M. A.

    New results are reported from time-projection-chamber measurements of the double beta decay of 100Mo and 150Nd. A previously-observed high-energy anomaly has been eliminated by improved energy resolution. Kurie plots of the two-neutrino spectra show end-point energies close to the reported parent-daughter mass differences. The 150Nd source has produced a new direct-counting 90% confidence neutrino-majoron coupling limit of < gν, χ> < 7.0 × 10 -5. The strengths and weaknesses of the TPC, and the feasibility of a larger TPC for neutrinoless double beta decay are discussed.

  18. Observation of Two-Neutrino Double-Beta Decay in Xe-136 with EXO-200

    SciTech Connect

    Ackerman, N.; Aharmim, B.; Auger, M.; Auty, D.J.; Barbeau, P.S.; Barry, K.; Bartoszek, L.; Beauchamp, E.; Belov, V.; Benitez-Medina, C.; Breidenbach, M.; Burenkov, A.; Cleveland, B.; Conley, R.; Conti, E.; Cook, J.; Cook, S.; Coppens, A.; Counts, I.; Craddock, W.; Daniels, T.; /more authors..

    2012-09-14

    We report the observation of two-neutrino double-beta decay in {sup 136}Xe with T{sub 1/2} = 2.11 {+-} 0.04(stat) {+-} 0.21(syst) x 10{sup 21} yr. This second-order process, predicted by the standard model, has been observed for several nuclei but not for {sup 136}Xe. The observed decay rate provides new input to matrix element calculations and to the search for the more interesting neutrinoless double-beta decay, the most sensitive probe for the existence of Majorana particles and the measurement of the neutrino mass scale.

  19. Current double beta decay experiments

    NASA Astrophysics Data System (ADS)

    Giuliani, A.

    2005-01-01

    After an introduction about double beta decay and the deep connections between the lepton-violating channel and the neutrino properties, the most sensitive experimental approaches to the search for this rare nuclear transition are described. An overview of the experiments presently running is then given, with particular emphasis on the adopted techniques and their possible extrapolation to next-generation, higher-sensitivity experiments. The present situation about the experimental determination of the Majorana neutrino mass is presented and discussed.

  20. Nuclear matrix elements of the double beta decay for mass around 80

    NASA Astrophysics Data System (ADS)

    Yoshinaga, Naotaka; Higashiyama, Koji; Teruya, Eri

    2014-09-01

    In nature there are 30 kinds of nuclei which are expected to have double beta decays. Among them ten nuclei are actually observed for the neutrino double beta decays. Still no observation is made for the neutrinoless double beta decays (0 νββ) . The 0 νββ decay is expected to occur only when neutrinos have masses and they are Majorana particles. In that respect observation of 0 νββ is to determine whether neutrinos are Majorana particles or not. In theoretical side in order to estimate the half life of 0 νββ determination of the nuclear matrix elements are essential. They were calculated in many theoretical frameworks, but the results are not consistent in various models. In this study we carry out shell model calculations for 82Se and 82Kr nuclei. After obtaining the wavefunctions, we calculate the nuclear matrix elements. For comparison we make pair truncated shell model calculations.

  1. Radiopurity control in the NEXT-100 double beta decay experiment

    NASA Astrophysics Data System (ADS)

    Álvarez, V.; Bandac, I.; Bettini, A.; Borges, F. I. G. M.; Cárcel, S.; Castel, J.; Cebrián, S.; Cervera, A.; Conde, C. A. N.; Dafni, T.; Dias, T. H. V. T.; Díaz, J.; Egorov, M.; Esteve, R.; Evtoukhovitch, P.; Fernandes, L. M. P.; Ferrario, P.; Ferreira, A. L.; Freitas, E. D. C.; Gehman, V. M.; Gil, A.; Goldschmidt, A.; Gómez, H.; Gómez-Cadenas, J. J.; González-Díaz, D.; Gutiérrez, R. M.; Hauptman, J.; Hernando Morata, J. A.; Herrera, D. C.; Iguaz, F. J.; Irastorza, I. G.; Jinete, M. A.; Labarga, L.; Laing, A.; Liubarsky, I.; Lopes, J. A. M.; Lorca, D.; Losada, M.; Luzón, G.; Marí, A.; Martín-Albo, J.; Martínez, A.; Miller, T.; Moiseenko, A.; Monrabal, F.; Monteiro, C. M. B.; Mora, F. J.; Moutinho, L. M.; Muñoz Vidal, J.; da Luz, H. Natal; Navarro, G.; Nebot-Guinot, M.; Nygren, D.; Oliveira, C. A. B.; de Solórzano, A. Ortiz; Palma, R.; Pérez, J.; Pérez Aparicio, J. L.; Renner, J.; Ripoll, L.; Rodríguez, A.; Rodríguez, J.; Santos, F. P.; dos Santos, J. M. F.; Segui, L.; Serra, L.; Shuman, D.; Simón, A.; Sofka, C.; Sorel, M.; Toledo, J. F.; Tomás, A.; Torrent, J.; Tsamalaidze, Z.; Vázquez, D.; Veloso, J. F. C. A.; Villar, J. A.; Webb, R. C.; White, J. T.; Yahlali, N.

    2013-08-01

    An extensive material screening and selection process is underway in the construction of the "Neutrino Experiment with a Xenon TPC" (NEXT), intended to investigate neutrinoless double beta decay using a high-pressure xenon gas TPC filled with 100 kg of Xe enriched in 136Xe. Determination of the radiopurity levels of the materials is based on gamma-ray spectroscopy using ultra-low background germanium detectors at the Laboratorio Subterráneo de Canfranc (Spain) and also on Glow Discharge Mass Spectrometry. Materials to be used in the shielding, pressure vessel, electroluminescence and high voltage components and energy and tracking readout planes have been already taken into consideration. The measurements carried out are presented, describing the techniques and equipment used, and the results obtained are shown, discussing their implications for the NEXT experiment.

  2. Radiopurity control in the NEXT-100 double beta decay experiment

    SciTech Connect

    Álvarez, V.; Cárcel, S.; Cervera, A.; Díaz, J.; Ferrario, P.; Gil, A.; Gómez-Cadenas, J. J.; Laing, A.; Liubarsky, I.; Lorca, D.; Martín-Albo, J.; Martínez, A.; Monrabal, F.; Muñoz Vidal, J.; Nebot-Guinot, M.; Rodríguez, J.; Serra, L.; Simón, A.; Sofka, C.; Sorel, M.; and others

    2013-08-08

    An extensive material screening and selection process is underway in the construction of the 'Neutrino Experiment with a Xenon TPC' (NEXT), intended to investigate neutrinoless double beta decay using a high-pressure xenon gas TPC filled with 100 kg of Xe enriched in {sup 136}Xe. Determination of the radiopurity levels of the materials is based on gamma-ray spectroscopy using ultra-low background germanium detectors at the Laboratorio Subterráneo de Canfranc (Spain) and also on Glow Discharge Mass Spectrometry. Materials to be used in the shielding, pressure vessel, electroluminescence and high voltage components and energy and tracking readout planes have been already taken into consideration. The measurements carried out are presented, describing the techniques and equipment used, and the results obtained are shown, discussing their implications for the NEXT experiment.

  3. Double Beta Decay in Xenon-136. Measuring the Neutrino-Emitting Mode and Searching for Majoron-Emitting Modes

    SciTech Connect

    Herrin, Steven

    2013-06-01

    Observations of neutrino flavor oscillations have demonstrated that neutrinos have mass. Since the discovery of these oscillations, much progress has been made at mea- suring the neutrino mass-squared differences and lepton mixing angles that character- ize them. However, the origin and absolute scale of neutrino masses remain unknown. Unique among fermions, neutrinos can be Majorana particles, which could provide an explanation for neutrino masses. Discovery of a hypothetical process known as neutrinoless double beta decay would show that neutrinos are Majorana particles and determine the mass scale for neutrinos. The Enriched Xenon Observatory (EXO) is a series of experiments searching for the neutrinoless double beta decay of 136Xe. The first experiment, EXO-200, began operation in 2011 and makes use of 200 kg of xenon enriched to 80.6% in 136Xe. The analysis presented here makes use of data from EXO-200 to obtain a more precise measurement of the half-life for the two-neutrino-emitting mode of double beta decay than previously reported. The analysis also sets limits on the half-lives for exotic, Majoron-emitting modes of neutrinoless double beta decay. Data from EXO-200 is also used to produce a measurement of the cosmic muon flux at the WIPP under- ground site where EXO-200 is located.

  4. Search for double beta decay of 116Cd with enriched 116CdWO4 crystal scintillators (Aurora experiment)

    NASA Astrophysics Data System (ADS)

    Danevich, F. A.; Barabash, A. S.; Belli, P.; Bernabei, R.; Cappella, F.; Caracciolo, V.; Cerulli, R.; Chernyak, D. M.; d'Angelo, S.; Incicchitti, A.; Kobychev, V. V.; Konovalov, S. I.; Laubenstein, M.; Mokina, V. M.; Poda, D. V.; Polischuk, O. G.; Shlegel, V. N.; Tretyak, V. I.; Umatov, V. I.

    2016-05-01

    The Aurora experiment to investigate double beta decay of 116 Cd with the help of 1.162 kg cadmium tungstate crystal scintillators enriched in 116 Cd to 82% is in progress at the Gran Sasso Underground Laboratory. The half-life of 116 Cd relatively to the two neutrino double beta decay is measured with the highest up-to-date accuracy T1/2 = (2.62 ± 0.14) × 1019 yr. The sensitivity of the experiment to the neutrinoless double beta decay of 116 Cd to the ground state of 116 Sn is estimated as T1/2 ≥ 1.9 × 1023 yr at 90% CL, which corresponds to the effective Majorana neutrino mass limit (mv) ≤ (1.2 — 1.8) eV. New limits are obtained for the double beta decay of 116 Cd to the excited levels of 116 Sn, and for the neutrinoless double beta decay with emission of majorons.

  5. Observation of Two-Neutrino Double-Beta Decay in Xe136 with the EXO-200 Detector

    NASA Astrophysics Data System (ADS)

    Ackerman, N.; Aharmim, B.; Auger, M.; Auty, D. J.; Barbeau, P. S.; Barry, K.; Bartoszek, L.; Beauchamp, E.; Belov, V.; Benitez-Medina, C.; Breidenbach, M.; Burenkov, A.; Cleveland, B.; Conley, R.; Conti, E.; Cook, J.; Cook, S.; Coppens, A.; Counts, I.; Craddock, W.; Daniels, T.; Danilov, M. V.; Davis, C. G.; Davis, J.; Devoe, R.; Djurcic, Z.; Dobi, A.; Dolgolenko, A. G.; Dolinski, M. J.; Donato, K.; Dunford, M.; Fairbank, W., Jr.; Farine, J.; Fierlinger, P.; Franco, D.; Freytag, D.; Giroux, G.; Gornea, R.; Graham, K.; Gratta, G.; Green, M. P.; Hägemann, C.; Hall, C.; Hall, K.; Haller, G.; Hargrove, C.; Herbst, R.; Herrin, S.; Hodgson, J.; Hughes, M.; Johnson, A.; Karelin, A.; Kaufman, L. J.; Koffas, T.; Kuchenkov, A.; Kumar, A.; Kumar, K. S.; Leonard, D. S.; Leonard, F.; Leport, F.; Mackay, D.; MacLellan, R.; Marino, M.; Martin, Y.; Mong, B.; Montero Díez, M.; Morgan, P.; Müller, A. R.; Neilson, R.; Nelson, R.; Odian, A.; O'Sullivan, K.; Ouellet, C.; Piepke, A.; Pocar, A.; Prescott, C. Y.; Pushkin, K.; Rivas, A.; Rollin, E.; Rowson, P. C.; Russell, J. J.; Sabourov, A.; Sinclair, D.; Skarpaas, K.; Slutsky, S.; Stekhanov, V.; Strickland, V.; Swift, M.; Tosi, D.; Twelker, K.; Vogel, P.; Vuilleumier, J.-L.; Vuilleumier, J.-M.; Waite, A.; Waldman, S.; Walton, T.; Wamba, K.; Weber, M.; Wichoski, U.; Wodin, J.; Wright, J. D.; Yang, L.; Yen, Y.-R.; Zeldovich, O. Ya.

    2011-11-01

    We report the observation of two-neutrino double-beta decay in Xe136 with T1/2=2.11±0.04(stat)±0.21(syst)×1021yr. This second-order process, predicted by the standard model, has been observed for several nuclei but not for Xe136. The observed decay rate provides new input to matrix element calculations and to the search for the more interesting neutrinoless double-beta decay, the most sensitive probe for the existence of Majorana particles and the measurement of the neutrino mass scale.

  6. Observation of two-neutrino double-beta decay in 136Xe with the EXO-200 detector.

    PubMed

    Ackerman, N; Aharmim, B; Auger, M; Auty, D J; Barbeau, P S; Barry, K; Bartoszek, L; Beauchamp, E; Belov, V; Benitez-Medina, C; Breidenbach, M; Burenkov, A; Cleveland, B; Conley, R; Conti, E; Cook, J; Cook, S; Coppens, A; Counts, I; Craddock, W; Daniels, T; Danilov, M V; Davis, C G; Davis, J; deVoe, R; Djurcic, Z; Dobi, A; Dolgolenko, A G; Dolinski, M J; Donato, K; Dunford, M; Fairbank, W; Farine, J; Fierlinger, P; Franco, D; Freytag, D; Giroux, G; Gornea, R; Graham, K; Gratta, G; Green, M P; Hägemann, C; Hall, C; Hall, K; Haller, G; Hargrove, C; Herbst, R; Herrin, S; Hodgson, J; Hughes, M; Johnson, A; Karelin, A; Kaufman, L J; Koffas, T; Kuchenkov, A; Kumar, A; Kumar, K S; Leonard, D S; Leonard, F; LePort, F; Mackay, D; MacLellan, R; Marino, M; Martin, Y; Mong, B; Díez, M Montero; Morgan, P; Müller, A R; Neilson, R; Nelson, R; Odian, A; O'Sullivan, K; Ouellet, C; Piepke, A; Pocar, A; Prescott, C Y; Pushkin, K; Rivas, A; Rollin, E; Rowson, P C; Russell, J J; Sabourov, A; Sinclair, D; Skarpaas, K; Slutsky, S; Stekhanov, V; Strickland, V; Swift, M; Tosi, D; Twelker, K; Vogel, P; Vuilleumier, J-L; Vuilleumier, J-M; Waite, A; Waldman, S; Walton, T; Wamba, K; Weber, M; Wichoski, U; Wodin, J; Wright, J D; Yang, L; Yen, Y-R; Zeldovich, O Ya

    2011-11-18

    We report the observation of two-neutrino double-beta decay in (136)Xe with T(1/2) = 2.11 ± 0.04(stat) ± 0.21(syst) × 10(21) yr. This second-order process, predicted by the standard model, has been observed for several nuclei but not for (136)Xe. The observed decay rate provides new input to matrix element calculations and to the search for the more interesting neutrinoless double-beta decay, the most sensitive probe for the existence of Majorana particles and the measurement of the neutrino mass scale.

  7. The MAJORANA DEMONSTRATOR: A Search for Neutrino less Double-beta Decay of Ge-76

    SciTech Connect

    Xu, W.; Abgrall, N.; Avignone, III, F. T.; Bertrand, F. E.; Efremenko, Yuri; Galindo-Uribarri, Alfredo {nmn}; Green, M. P.; Radford, D. C.; Romero-Romero, E.; White, B. R.; Wilkerson, J. F.

    2015-01-01

    Neutrino less double-beta (Ov beta beta) decay is a hypothesized process where in some even-even nuclei it might be possible for two neutrons to simultaneously decay into two protons and two electrons without emitting neutrinos. This is possible only if neutrinos are Majorana particles, i.e. fermions that are their own antiparticles. Neutrinos being Majorana particles would explicitly violate lepton number conservation, and might play a role in the matter-antimatter asymmetry in the universe. The observation of neutrinoless double-beta decay would also provide complementary information related to neutrino masses. The MAJORANA Collaboration is constructing the MAJORANA DEMONSTRATOR, with a total of 40-kg Germanium detectors, to search for the Ov beta beta decay of Ge-76 and to demonstrate a background rate at or below 3 counts/ (ROI.t.y) in the 4 keV region of interest (ROT) around the 2039 keV Q-value for Ge-76 Ov beta beta decay. In this paper, we discuss the physics of neutrinoless double beta decay and then focus on the MAJORANA DEMONSTRATOR, including its design and approach to achieve ultra-low backgrounds and the status of the experiment.

  8. SNO+ status and plans for double beta decay search and other neutrino studies

    NASA Astrophysics Data System (ADS)

    Andringa, S.; SNO+ Collaboration

    2016-01-01

    SNO+ is a multi-purpose Neutrino Physics experiment, succeeding to the Sudbury Neutrino Observatory by replacing heavy water with liquid scintillator, which can also be loaded with large quantities of double-beta decaying isotope. The scientific goals of SNO+ are the search for neutrinoless double-beta decay, the study of solar neutrinos and of anti-neutrinos from nuclear reactors and the Earth's natural radioactivity, as well as supernovae neutrinos. The installation of the detector at SNOLAB is being completed and commissioning has already started with a dry run. The detector will soon be filled with water and, later, with scintillator. Here we highlight the main detector developments and address the several Physics analysis being prepared for the several planned SNO+ runs.

  9. Average and recommended half-life values for two neutrino double beta decay: Upgrade-2013

    SciTech Connect

    Barabash, A. S.

    2013-12-30

    All existing positive results on two neutrino double beta decay in different nuclei were analyzed. Using the procedure recommended by the Particle Data Group, weighted average values for half-lives of {sup 48}Ca, {sup 76}Ge, {sup 82}Se, {sup 96}Zr, {sup 100}Mo, {sup 100}Mo−{sup 100}Ru (0{sub 1}{sup +}), {sup 116}Cd, {sup 130}Te, {sup 136}Xe, {sup 150}Nd, {sup 150}Nd−{sup 150}Sm (0{sub 1}{sup +}) and {sup 238}U were obtained. Existing geochemical data were analyzed and recommended values for half-lives of {sup 128}Te and {sup 130}Ba are proposed. I recommend the use of these results as the most currently reliable values for half-lives.

  10. Shell-Model Calculations of Two-Nucleon Tansfer Related to Double Beta Decay

    NASA Astrophysics Data System (ADS)

    Brown, Alex

    2013-10-01

    I will discuss theoretical results for two-nucleon transfer cross sections for nuclei in the regions of 48Ca, 76Ge and 136Xe of interest for testing the wavefuntions used for the nuclear matrix elements in double-beta decay. Various reaction models are used. A simple cluster transfer model gives relative cross sections. Thompson's code Fresco with direct and sequential transfer is used for absolute cross sections. Wavefunctions are obtained in large-basis proton-neutron coupled model spaces with the code NuShellX with realistic effecive Hamiltonians such as those used for the recent results for 136Xe [M. Horoi and B. A. Brown, Phys. Rev. Lett. 110, 222502 (2013)]. I acknowledge support from NSF grant PHY-1068217.

  11. Search for the Neutrino Less Double Beta Decay

    SciTech Connect

    Efremenko, Yuri

    2016-07-11

    During the past few years our understanding of neutrino properties has reached a new level, with experiments such as Super-K, SNO, KamLAND, and others obtaining exciting results. Major questions such as “Do neutrinos have mass?” and “Do neutrinos oscillate?” now have positive answers. However, an extensive program of neutrino research remains. Undoubtedly, the most important of these is the question pointed out by the National Research Council in its February 2002 report “Connecting Quarks with the Cosmos”, specifically: What are the masses of neutrinos and how have they shaped the evolution of the Universe? The MAJORANA collaboration has proposed to build the world’s most sensitive one-ton scale experiment to search for neutrino less double beta decay to answer this question. In its initial stage, the collaboration is building a prototype MAJORANA DEMONSTRATOR (MJD) experiment consisting of detectors made out of enriched Ge76 with a total sensitive mass of ~30 kg. This will accomplish two goals. First, it will test not yet confirmed claim for observation of neutrino-less double beta decay. Second, it will establish that the selected technology is capable of extension to a one-ton experiment with sufficient sensitivity to measure neutrino mass mββ down to 10 meV. To achieve the last goal, collaboration must demonstrate that a background level of 1 count per year per 4 keV per ton of detector is achievable. The University of Tennessee (UT) neutrino group has made a major commitment to the MJD. P.I. accepted the responsibility for one of the major tasks of the experiment, “Materials and Assay Task” which is crucial to the achievement of low background levels required for the experiment. In addition, the UT group is committed to construct, commission, and operate the MJD active veto system. Those activities were supported by NP-DOE via program funding for “Search for the Neutrino Less Double Beta Decay” at the University

  12. MOON for symmetry studies of neutrinos by double beta decays and neutrino nuclear responses

    NASA Astrophysics Data System (ADS)

    Ejiri, H.

    2010-11-01

    Neutrino-less double beta decays (0νββ) are used for high sensitivity studies of symmetry properties of neutrinos such as the Majorana nature of neutrinos, the absolute mass scale, the CP at the lepton sector, and others. Neutrino nuclear responses (0νββ nuclear matrix elements) are crucial for extracting these neutrino properties from 0νββ experiments. This is a brief report of the present status of MOON (spectroscopic 0νββ experiment) with the ν-mass sensitivity of 100-30 meV, and experimental ways to study the neutrino nuclear responses.

  13. Double-Beta Decay at TUNL

    NASA Astrophysics Data System (ADS)

    Kidd, Mary

    2007-10-01

    Studying double-beta decay at Triangle Universities Nuclear Laboratory (TUNL) is perhaps one of the most promising ways to pinpoint the neutrino mass. What they do not mention is that to study double-beta decay, you probably have to become a certified miner, and if you have a fear of goats, you should stay away. In this talk, I will tell you some of my experiences as a TUNL graduate student, and how I am now nearly qualified for a job in the mining industry.

  14. Double-beta decay in pn-QRPA model with isospin and SU(4) symmetry constraints

    NASA Astrophysics Data System (ADS)

    Krmpotić, F.; Sharma, S. Shelly

    1994-05-01

    The transition matrix elements for the 0 + → 0 + double-beta decays are calculated for 48Ca, 76Ge, 82Se, 100Mo, 128Te and 130Te nuclei, using a δ-interaction. As a guide, to fix the particle-particle interaction strengths, we exploit the fact that the missing symmetries of the mean-field approximation are restored in the random phase approximation by the residual interaction. Thus, the T = 1, S = 0 and T = 0, S = 1 coupling strengths have been estimated by invoking the partial restoration of the isospin and Wigner SU(4) symmetries, respectively. When this recipe is strictly applied, the calculation is consistent with the experimental limit for the 2ν lifetime of 48Ca and it also correctly reproduces the 2ν lifetime of 82Se. In this way, however, the two-neutrino matrix elements for the remaining nuclei are either underestimated (for 76Ge and 100Mo) or overestimated (for 128Te and 130Te) approximately by a factor of 3. With a comparatively small variation (< 10%) of the spin-triplet parameter, near the value suggested by the SU(4) symmetry, it is possible to reproduce the measured T 2ν{1}/{2} all the cases. The upper limit for the effective neutrino mass, as obtained from the theoretical estimates of 0ν matrix elements, is < m> ˜- 1 eV. The dependence of the nuclear matrix elements on the size of the configuration space has been also analyzed.

  15. Double beta decay: recent developments and projections

    SciTech Connect

    Avignone, F.T. III; Brodzinski, R.L.; Brown, D.P.; Evans, J.C. Jr.; Hensley, W.K.; Reeves, J.H.; Wogman, N.A.

    1983-08-01

    A report of recent events in both theoretical and experimental aspects of double beta decay is given. General theoretical considerations, recent developments in nuclear structure theory, geochronological determinations of half lives and ratios as well as laboratory experiments are discussed with emphasis on the past three years. Some projections are given. 28 references.

  16. Nuclear-structure aspects of double beta decay

    SciTech Connect

    Suhonen, Jouni

    2010-11-24

    Neutrinoless double beta (0{nu}{beta}{beta}) decay of nuclei is a process that requires the neutrino to be a massive Majorana particle and thus cannot proceed in the standard model of electro-weak interactions. Recent results of the neutrino-oscillation experiments have produced accurate information on the mixing of neutrinos and their squared mass differences. The 0{nu}{beta}{beta} decay takes place in atomic nuclei where it can be observed, at least in principle, by underground neutrino experiments. The need of nuclei in observation of the 0{nu}{beta}{beta} decay bears two facets: The nucleus serves as laboratory for detection but at the same time its complicated many-nucleon structure interferes strongly with the analysis of the experimental data. The information about the weak-interaction observables, like the neutrino mass, has to be filtered from the data through the nuclear matrix elements (NMEs). Hence, exact knowledge about the NMEs is of paramount importance in the analysis of the data provided by the expensive and time-consuming underground experiments.

  17. New Technique for Barium Daughter Ion Identification in a Liquid Xe-136 Double Beta Decay Experiment

    SciTech Connect

    Fairbank, William

    2016-06-08

    This work addresses long-standing issues of fundamental interest in elementary particle physics. The most important outcome of this work is a new limit on neutrinoless double beta decay. This is an extremely rare and long-sought-after type of radioactive decay. If discovered, it would require changes in the standard model of the elementary constituents of matter, and would prove that neutrinos and antineutrinos are the same, a revolutionary concept in particle physics. Neutrinos are major components of the matter in the universe that are so small and so weakly interacting with other matter that their masses have not yet been discovered. A discovery of neutrinoless double beta decay could help determine the neutrino masses. An important outcome of the work on this project was the Colorado State University role in operating the EXO-200 neutrinoless double beta decay experiment and in analysis of the data from this experiment. One type of double beta decay of the isotope 136Xe, the two-neutrino variety, was discovered in this work. Although the other type of double beta decay, the neutrinoless variety, was not yet discovered in this work, a world’s best sensitivity of 1.9x1025 year half-life was obtained. This result rules out a previous claim of a positive result in a different isotope. This work also establishes that the masses of the neutrinos are less than one millionth of that of electrons. A unique EXO-200 analysis, in which the CSU group had a leading role, has established for the first time ever in a liquid noble gas the fraction of daughter atoms from alpha and beta decay that are ionized. This result has important impact on other pending studies, including nucleon decay and barium tagging. Novel additional discoveries include multiphoton ionization of liquid xenon with UV pulsed lasers, which may find application in calibration of future noble liquid detectors, and studies of association and dissociation reactions of Ba

  18. First results on double {beta}-decay modes of Cd, Te, and Zn Isotopes

    SciTech Connect

    Bloxham, T.; Freer, M.; Boston, A.; Nolan, P.; Dawson, J.; Reeve, C.; Wilson, J. R.; Zuber, K.; Dobos, D.; Goessling, C.; Kiel, H.; Muenstermann, D.; Oehl, S.; Fox, S. P.; Fulton, B. R.; McGrath, J.; Wadsworth, R.; Harrison, P. F.; Morgan, B.; Ramachers, Y.

    2007-08-15

    Four 1-cm{sup 3} CdZnTe semiconductor detectors were operated in the Gran Sasso National Laboratory to explore the feasibility of such devices for double {beta}-decay searches as proposed for the COBRA experiment. The research involved background studies accompanied by measurements of energy resolution performed at the surface. Energy resolutions sufficient to reduce the contribution of two-neutrino double {beta}-decay events to a negligible level for a large-scale experiment have already been achieved and further improvements are expected. Using activity measurements of contaminants in all construction materials a background model was developed with the help of Monte Carlo simulations and major background sources were identified. A total exposure of 4.34 kg{center_dot}days of underground data have been accumulated allowing a search for neutrinoless double {beta}-decay modes of seven isotopes found in CdZnTe. Half-life limits (90% C.L.) are presented for decays to ground and excited states. Four improved lower limits have been obtained, including zero neutrino double electron capture transitions of {sup 64}Zn and {sup 120}Te to the ground state, which are 1.19x10{sup 17} years and 2.68x10{sup 15} years, respectively.

  19. Measurement of the two-neutrino double-beta decay half-life of ^{130}Te with the CUORE-0 experiment

    NASA Astrophysics Data System (ADS)

    Alduino, C.; Alfonso, K.; Artusa, D. R.; Avignone, F. T.; Azzolini, O.; Banks, T. I.; Bari, G.; Beeman, J. W.; Bellini, F.; Bersani, A.; Biassoni, M.; Brofferio, C.; Bucci, C.; Camacho, A.; Caminata, A.; Canonica, L.; Cao, X. G.; Capelli, S.; Cappelli, L.; Carbone, L.; Cardani, L.; Carniti, P.; Casali, N.; Cassina, L.; Chiesa, D.; Chott, N.; Clemenza, M.; Copello, S.; Cosmelli, C.; Cremonesi, O.; Creswick, R. J.; Cushman, J. S.; D'Addabbo, A.; Dafinei, I.; Davis, C. J.; Dell'Oro, S.; Deninno, M. M.; Di Domizio, S.; Di Vacri, M. L.; Drobizhev, A.; Fang, D. Q.; Faverzani, M.; Feintzeig, J.; Fernandes, G.; Ferri, E.; Ferroni, F.; Fiorini, E.; Franceschi, M. A.; Freedman, S. J.; Fujikawa, B. K.; Giachero, A.; Gironi, L.; Giuliani, A.; Gladstone, L.; Gorla, P.; Gotti, C.; Gutierrez, T. D.; Haller, E. E.; Han, K.; Hansen, E.; Heeger, K. M.; Hennings-Yeomans, R.; Hickerson, K. P.; Huang, H. Z.; Kadel, R.; Keppel, G.; Kolomensky, Yu. G.; Leder, A.; Ligi, C.; Lim, K. E.; Liu, X.; Ma, Y. G.; Maino, M.; Marini, L.; Martinez, M.; Maruyama, R. H.; Mei, Y.; Moggi, N.; Morganti, S.; Mosteiro, P. J.; Napolitano, T.; Nones, C.; Norman, E. B.; Nucciotti, A.; O'Donnell, T.; Orio, F.; Ouellet, J. L.; Pagliarone, C. E.; Pallavicini, M.; Palmieri, V.; Pattavina, L.; Pavan, M.; Pessina, G.; Pettinacci, V.; Piperno, G.; Pira, C.; Pirro, S.; Pozzi, S.; Previtali, E.; Rosenfeld, C.; Rusconi, C.; Sangiorgio, S.; Santone, D.; Scielzo, N. D.; Singh, V.; Sisti, M.; Smith, A. R.; Taffarello, L.; Tenconi, M.; Terranova, F.; Tomei, C.; Trentalange, S.; Vignati, M.; Wagaarachchi, S. L.; Wang, B. S.; Wang, H. W.; Wilson, J.; Winslow, L. A.; Wise, T.; Woodcraft, A.; Zanotti, L.; Zhang, G. Q.; Zhu, B. X.; Zimmermann, S.; Zucchelli, S.

    2017-01-01

    We report on the measurement of the two-neutrino double-beta decay half-life of ^{130}Te with the CUORE-0 detector. From an exposure of 33.4 kg year of TeO_2, the half-life is determined to be T_{1/2}^{2ν } = [8.2 ± 0.2 (stat.) ± 0.6 (syst.)] × 10^{20} year. This result is obtained after a detailed reconstruction of the sources responsible for the CUORE-0 counting rate, with a specific study of those contributing to the ^{130}Te neutrinoless double-beta decay region of interest.

  20. CANDLES for the study of ^48Ca double beta decay

    NASA Astrophysics Data System (ADS)

    Ogawa, Izumi

    2009-10-01

    CANDLES is the project to search for double beta decay (DBD) of ^48Ca by using CaF2 scintillators. The Q-value of ^48Ca, which is the highest (4.27 MeV) among potential DBD nuclei, is far above energies of γ-rays from natural radioactivities (maximum 2.615 MeV from ^208Tl decay), therefore we can naturally expect small backgrounds in the energy region we are interested in. We gave the best lower limit on the half-life of neutrino-less double beta decay of ^48Ca by using CaF2(Eu) detector system, ELEGANT VI though further development is highly desirable to reach the mass region of current interest. We have constructed the prototype detector, CANDLES III in our laboratory (Osaka U.) at sea level and studied the basic performance of the system, including the light collection, position reconstruction and background rejection. We are now moving the detector system to new experimental room (room D) at Kamioka underground laboratory (2700 m.w.e.) to avoid large background originated from cosmic rays. At the same time, we are increasing the total mass of the ^48Ca compared to the one in the prototype detector. 96 (instead of 60 in prototype) CaF2 modules which contains 350 g of ^48Ca are immersed in a liquid scintillator (LS) which acts as an active veto (veto phase). The conversion phase contains wavelength shifter (Bis-MSB) which converts the emission light of CaF2(pure) which has a peak in the UV region to the visible one where the quantum efficiency of the PMTs is high enough (maximum at ˜400 nm) and materials at the optical path have good transparencies. Scintillation lights from both the CaF2 modules and the liquid scintillator in veto phase are viewed by large PMTs (48 x13'' and 14 x17'' tubes). All the detector system described above are contained in a water tank which is 3 m in diameter and 4 m in height. The water tank and a purification system of the LS together with LS storage tanks were installed at room D. The purification system of the LS removes the

  1. Sense and sensitivity of double beta decay experiments

    NASA Astrophysics Data System (ADS)

    Gómez-Cadenas, J. J.; Martín-Albo, J.; Sorel, M.; Ferrario, P.; Monrabal, F.; Muñoz, J.; Novella, P.; Poves, A.

    2011-06-01

    The search for neutrinoless double beta decay is a very active field in which the number of proposals for next-generation experiments has proliferated. In this paper we attempt to address both the sense and the sensitivity of such proposals. Sensitivity comes first, by means of proposing a simple and unambiguous statistical recipe to derive the sensitivity to a putative Majorana neutrino mass, mββ. In order to make sense of how the different experimental approaches compare, we apply this recipe to a selection of proposals, comparing the resulting sensitivities. We also propose a ``physics-motivated range'' (PMR) of the nuclear matrix elements as a unifying criterium between the different nuclear models. The expected performance of the proposals is parametrized in terms of only four numbers: energy resolution, background rate (per unit time, isotope mass and energy), detection efficiency, and ββ isotope mass. For each proposal, both a reference and an optimistic scenario for the experimental performance are studied. In the reference scenario we find that all the proposals will be able to partially explore the degenerate spectrum, without fully covering it, although four of them (KamLAND-Zen, CUORE, NEXT and EXO) will approach the 50 meV boundary. In the optimistic scenario, we find that CUORE and the xenon-based proposals (KamLAND-Zen, EXO and NEXT) will explore a significant fraction of the inverse hierarchy, with NEXT covering it almost fully. For the long term future, we argue that 136Xe-based experiments may provide the best case for a 1-ton scale experiment, given the potentially very low backgrounds achievable and the expected scalability to large isotope masses.

  2. Pattern recognition techniques to reduce backgrounds in the search for the {sup 136}Xe double beta decay with gaseous TPCs

    SciTech Connect

    Iguaz, F. J.; Cebrián, S.; Dafni, T.; Gómez, H.; Herrera, D. C.; Irastorza, I. G.; Luzon, G.; Segui, L.; Tomas, A.

    2013-08-08

    The observation of the neutrinoless double beta decay may provide essential information on the nature of neutrinos. Among the current experimental approaches, a high pressure gaseous TPC is an attractive option for the search of double beta decay due to its good energy resolution and the detailed topological information of each event. We present in this talk a detailed study of the ionization topology of the {sup 136}Xe double beta decay events in a High Pressure Xenon TPC, as well as that of the typical competing backgrounds. We define some observables based on graph theory concepts to develop automated discrimination algorithms. Our criteria are able to reduce the background level by about three orders of magnitude in the region of interest of the {sup 136}Xe Q{sub ββ} for a signal acceptance of 40%. This result provides a quantitative assessment of the benefit of topological information offered by gaseous TPCs for double beta decay search, and proves that it is a promising feature in view of future experiments in the field. Possible ideas for further improvement in the discrimination algorithms and the dependency of these results with the gas diffusion and readout granularity will be also discussed.

  3. Inelastic neutron scattering cross sections for Ge76 relevant to background in neutrinoless double- β decay experiments

    DOE PAGES

    Crider, B. P.; Peters, E. E.; Allmond, J. M.; ...

    2015-09-11

    The experimental signature in searches for the neutrinoless double- decay of 76Ge is a peak near 2039 keV in the spectrum. Given the low probability of the process, it is important that the background in this region be well understood. Moreover, inelastic scattering reactions with neutrons from muon-induced interactions and ( ,n) reactions in the surrounding materials or in the detector can provide contributions to the background. We also measured the production cross sections for rays from the 76Ge(n,n ) reaction in the 2039-keV region at incident neutron energies up to 4.9 MeV. In addition to determining that the crossmore » sections of a previously known 2040.7-keV ray from the 3952-keV level in 76 Ge are rather small, we find that a larger contribution arises from a 2037.5-keV ray which is attributed to a newly identified level at 3147 keV in 76Ge. Finally, a third contribution is also possible from another new level at 3577 keV. These results indicate that the 2039-keV region in 76Ge neutrinoless double- decay searches is more complex than was previously thought.« less

  4. Two-Neutrino Double-Beta Decay.

    NASA Astrophysics Data System (ADS)

    Guerard Ortego, Carlos-Kjell

    1992-01-01

    Two previous independent reports of 2 nubetabeta-decay by the ITEP-YPI collaboration, rm T_sp{1/2} {2nu}=(9+/- 1) times 10^ {20} yr (1sigma), and PNL-USC group, rm T_sp{1/2 }{2nu}=(1.12_sp{-0.26} {+0.48}) times 10^{21} yr (2sigma), were confirmed using a 0.25 Kg Ge(Li) detector isotopically enriched to 86% in ^{76}Ge. The detector was operated in the PNL-USC ultralow background facility in the Homestake gold mine for 168 days. Following a single correction to the data, a spectrum resembling that of the earlier PNL-USC experiment, with about the same intensity per ^{76}Ge atom, per year, was observed with a measured half life of rm T_sp{1/2}{2nu}=(9.2 _sp{-0.4}{+0.7} times 10 ^{20} y (2sigma). This experiment is one of two presented in this dissertation as original work. The half-life of the 2nubeta beta-decay of ^{100} Mo to the 1130 keV level of ^{100 }Ru has been measured to be rm T_{1/2}=(1.1_sp{-0.2} {+0.3}) times 10^{21} y (90% C.L.), by observing the 590.76 and 539.53 keV gamma rays emitted in the 0_sp{1}{+ }to 2^+to 0^+ de -excitation cascade. A review of the most relevant nuclear structure calculations is given, and their predictions are compared to the measurements from our two experiments.

  5. Towards a Precise Energy Calibration of the CUORE Double Beta Decay Experiment

    NASA Astrophysics Data System (ADS)

    Dally, Adam G.

    The mass of the neutrino may hold the key to many problems in cosmology and astrophysics. The observation of neutrino oscillations shows that neutrinos have mass, which was something that was not accounted for in the Standard Model of particle physics. This thesis covers topics relating to measuring the value of neutrino mass directly using bolometers. The first section will discuss the neutrino mass and different experiments for measuring the mass using bolometers. The mass of the neutrino can be measured directly from beta-decay or inferred from observation of neutrinoless double beta decay (0nubetabeta). In this work I present Monte Carlo and analytic simulation of the MARE experiment including, pile-up and energy resolution effects. The mass measurement limits of a micro-calorimeter experiments as it relates to the quantity of decays measured is provided. A similar simulation is preformed for the HolMES experiment. The motivation is to determine the sensitivity of such experiments and the detector requirements to reach the goal sensitivity. Another possible method for determining the neutrino mass is to use neutrinoless double beta decay. The second section will cover the Cryogenic Underground Observatory for Rare Events (CUORE) detector calibration system (DCS). CUORE is a neutrinoless double beta decay (0nubetabeta) experiment with an active mass of 206 kg of 130Te. The detector consists of 988 TeO2 bolometers operating at 10 mK. The signature of 0 nubetabeta decay is an excess of events at the Q-value of 2528 keV. Understanding the energy response is critical for event identification, but this presents many challenges. Calibration is necessary to associate a known energy from a gamma with a voltage pulse from the detector. The DCS must overcome many design challenges. The calibration source must be placed safely and reliable within the detector. The temperature of the detector region of the cryostat must not be changed during calibration. To achieve this

  6. An experimental investigation of double beta decay of /sup 100/Mo

    SciTech Connect

    Dougherty, B.L.

    1988-11-17

    New limits on half-lives for several double beta decay modes of /sup 100/Mo were obtained with a novel experimental system which included thin source films interleaved with a coaxial array of windowless silicon detectors. Segmentation and timing information allowed backgrounds originating in the films to be studied in some detail. Dummy films containing /sup 96/Mo were used to assess remaining backgrounds. With 0.1 mole years of /sup 100/Mo data collected, the lower half-life limits at 90% confidence were 2.7 /times/ 10/sup 18/ years for decay via the two-neutrino mode, 5.2 /times/10/sup 19/ years for decay with the emission of a Majoron, and 1.6 /times/ 10/sup 20/ years and 2.2 /times/ 10/sup 21/ years for neutrinoless 0/sup +/ ..-->.. 2/sup +/ and 0/sup +/ ..-->.. 0/sup +/ transitions, respectively. 50 refs., 38 figs., 11 tabs.

  7. Present and future of double-beta decay searches with bolometric detectors

    NASA Astrophysics Data System (ADS)

    Cardani, L.

    2016-01-01

    Thanks to the excellent energy resolution, high efficiency and versatility, bolometric detectors are primed for the search of neutrinoless double-beta decay (0 ν DBD). The most advanced bolometric experiment, CUORE, is studying the 0 ν DBD of 130Te using a 741kg array of TeO2 crystals. CUORE points to a 90% CL sensitivity on the half-life of 0 ν DBD of 9.5×1025 yr in 5yr, corresponding to an upper limit on the neutrino Majorana mass of 50-130meV. This sensitivity will allow to touch, but not to explore, the region corresponding to the inverted hierarchy mass scenario. In this document I present the status of CUORE and the possible upgrades of the bolometric technology in view of a next generation experiment.

  8. First array of enriched Zn^{82}Se bolometers to search for double beta decay

    NASA Astrophysics Data System (ADS)

    Artusa, D. R.; Balzoni, A.; Beeman, J. W.; Bellini, F.; Biassoni, M.; Brofferio, C.; Camacho, A.; Capelli, S.; Cardani, L.; Carniti, P.; Casali, N.; Cassina, L.; Clemenza, M.; Cremonesi, O.; Cruciani, A.; D'Addabbo, A.; Dafinei, I.; Di Domizio, S.; di Vacri, M. L.; Ferroni, F.; Gironi, L.; Giuliani, A.; Gotti, C.; Keppel, G.; Maino, M.; Mancuso, M.; Martinez, M.; Morganti, S.; Nagorny, S.; Nastasi, M.; Nisi, S.; Nones, C.; Orio, F.; Orlandi, D.; Pagnanini, L.; Pallavicini, M.; Palmieri, V.; Pattavina, L.; Pavan, M.; Pessina, G.; Pettinacci, V.; Pirro, S.; Pozzi, S.; Previtali, E.; Puiu, A.; Rusconi, C.; Schäffner, K.; Tomei, C.; Vignati, M.; Zolotarova, A.

    2016-07-01

    The R&D activity performed during the last years proved the potential of ZnSe scintillating bolometers to the search for neutrino-less double beta decay, motivating the realization of the first large-mass experiment based on this technology: CUPID-0. The isotopic enrichment in ^{82}Se, the Zn^{82}Se crystals growth, as well as the light detectors production have been accomplished, and the experiment is now in construction at Laboratori Nazionali del Gran Sasso (Italy). In this paper we present the results obtained testing the first three Zn^{82}Se crystals operated as scintillating bolometers, and we prove that their performance in terms of energy resolution, background rejection capability and intrinsic radio-purity complies with the requirements of CUPID-0.

  9. Spin dipole nuclear matrix elements for double beta decay nuclei by charge-exchange reactions

    NASA Astrophysics Data System (ADS)

    Ejiri, H.; Frekers, D.

    2016-11-01

    Spin dipole (SD) strengths for double beta-decay (DBD) nuclei were studied experimentally for the first time by using measured cross sections of (3He, t) charge-exchange reactions (CERs). Then SD nuclear matrix elements (NMEs) {M}α ({{SD}}) for low-lying 2- states were derived from the experimental SD strengths by referring to the experimental α = GT (Gamow-Teller) and α = F (Fermi) strengths. They are consistent with the empirical NMEs M({{SD}}) based on the quasi-particle model with the empirical effective SD coupling constant. The CERs are used to evaluate the SD NME, which is associated with one of the major components of the neutrino-less DBD NME.

  10. MOON for double beta decays and X-rays from WIMP nuclear interactions

    NASA Astrophysics Data System (ADS)

    Ejiri, H.

    2006-07-01

    Neutrino-less double beta decays (0νββ) and direct observation of cold dark matter (DM) are of great interest for studying fundamental properties of neutrinos and weakly interacting massive particles (WIMPs). These are crucial for particle physics and cosmology beyond the standard electro-weak theory. The present seminar in the Erice neutrino school reports briefly (1) the effective neutrino mass studied by 0νββ, (2) the unique features and the present status of MOON (Molybdenum Observatory Of Neutrinos) for high-sensitivity 0νββ studies with 100Mo in the quasi-degenerate and inverted hierarchy regions, and (3) the direct detection of WIMPs by measuring atomic X-rays following inner-shell ionization by WIMPs nuclear interactions. The MOON project is carried out in collaboration with the MOON collaboration, and the X-ray work from WIMPs is done with Ch.C. Moustakidis and J.D. Vergados.

  11. Nuclear responses for double-beta decays by hadron, photon, and neutrino probes and MOON experiment

    NASA Astrophysics Data System (ADS)

    Ejiri, H.

    2006-05-01

    Neutrino-less double-beta decays (0νββ) with the mass sensitivities of the solar and atmospheric ν masses are of great interest for studying the Majorana nature of neutrinos and the absolute mass spectrum as suggested by recent ν oscillation experiments. Here nuclear responses (nuclear matrix elements) for 0νββ are crucial. They are well studied experimentally by using charge-exchange, photo-nuclear and neutrino reactions. MOON(Mo Observatory Of Neutrinos) is a high sensitivity 0νβ β experiment with the mass sensitivity of an order of 30 meV. Experimental studies of the nuclear responses and the present status of MOON are briefly discussed.

  12. Status and future prospect of 48Ca double beta decay search in CANDLES

    NASA Astrophysics Data System (ADS)

    Iida, T.; Nakajima, K.; Ajimura, S.; Batpurev, T.; Chan, W. M.; Fushimi, K.; Hazama, R.; Kakubata, H.; Khai, B. T.; Kishimoto, T.; Li, X.; Maeda, T.; Masuda, A.; Matsuoka, K.; Morishita, K.; Nakatani, N.; Nomachi, M.; Noshiro, S.; Ogawa, I.; Ohata, T.; Osumi, H.; Suzuki, K.; Tamagawa, Y.; Tesuno, K.; Trang, V. T. T.; Uehara, T.; Umehara, S.; Yoshida, S.

    2016-05-01

    The observation of neutrino-less double beta decay (0vßß) would be the most practical way to prove the Majorana nature of the neutrino and lepton number violation. CANDLES studies 48Ca double beta decay using CaF2 scintillator. The main advantage of 48Ca is that it has the highest Q-value (4.27 MeV) among all the isotope candidates for 0vßß. The CANDLES III detector is currently operating with 300kg CaF2 crystals in the Kamioka underground observatory, Japan. In 2014, a detector cooling system and a magnetic cancellation coil was installed with the aim to increase light emission of CaF2 scintillator and photo-electron collection efficiency of the photo-multipliers. After this upgrade, light yield was increased to 1000 p.e./MeV which is 1.6 times larger than before. According to data analysis and simulation, main background source in CANDLES is turned out to be high energy external gamma-ray originating neutron capture on the surrounding materials, so called (n,γ). Upgrading the detector by installing neutron and gamma-ray shield can reduce the remaining main backgrounds by two order magnitude. In this report, we discuss the detail of (n,γ) and background reduction by additional shielding.

  13. Capturing relic neutrinos with {beta}- and double {beta}-decaying nuclei

    SciTech Connect

    Hodak, Rastislav; Kovalenko, Sergey; Simkovic, Fedor

    2009-11-09

    Neutrinos are probably one of the most important structural constituents of the Universe. The Big Bang Theory predicts that the significant component of them is formed by the cosmic neutrino background, an analogues of the big bang relic photons comprising the cosmic microwave background radiation, which has been measured with amazing accuracy. Properties of the relic neutrino background are closely related to the ones of the cosmic microwave radiation. Relic neutrinos pervade space, but their temperature is extremely small, being of the order of 0.1 meV. Although belonging to the most abundant particles of the Universe, the relic neutrinos evade direct detection so far. This is because the low-energy neutrinos interact only very weakly with matter. In this contribution, we explore the feasibility to detect the cosmic neutrino background by means of {beta}-decaying ({sup 3}H and {sup 187}Re) and double beta decaying ({sup 100}Mo) nuclei. In addition, we address the question whether double relic neutrino capture on nuclei can be an obstacle for observation of neutrinoless double {beta}-decay.

  14. Bonner Prize Talk -- First Laboratory Observation of Double Beta Decay

    NASA Astrophysics Data System (ADS)

    Moe, Michael

    2013-04-01

    Although we are awash in neutrinos, we remain ignorant of some of their fundamental properties. We don't know their masses. We don't know whether ``anti-neutrinos'' are really distinct particles. Double beta (ββ) decay offers a handle on these questions if we can observe the energy spectrum of the two emitted electrons, and determine whether or not they share their energy with two neutrinos. Seeing neutrinoless (0ν) decay would solve some enduring puzzles. The power of the process to elucidate the neutrino was recognized in the 1930's, but ββ decay would be exceedingly rare and difficult to detect. Unsuccessful laboratory searches had been going on for 25 years when the UC Irvine group began its first experiment with a cloud chamber in 1972. After some background for the non-expert, and a snapshot of the theoretical and experimental milieu at the time, the talk will begin with the reasons for choosing a cloud chamber, and the taming of its balky and idiosyncratic behavior. The talk will end with the first definitive observation of two-neutrino (2ν)ββ decay of ^82Se in the vastly superior time projection chamber (TPC) in 1987. Discouragement through the tortuous 15-year interval was relieved by occasional victories. Some I will illustrate with revealing cloud-chamber photographs. We learned many things from this primitive device, and after seven years we isolated an apparent ββ decay signal. But the efficiency of the trigger was small, and difficult to pin down. Estimating 2.2%, we were way low. The resulting ``short'' ^82Se half-life of 1 x 10^19 years was suspect. New technology came to the rescue with the invention of the TPC. Experience with the cloud chamber guided our design of a TPC specifically for ββ decay. The TPC was built from scratch. Its long, steep learning curve was also punctuated with little triumphs. A memorable moment was the first turn-on of a portion of the chamber. So long ago, this all seems rather quaint, but through ample use of

  15. Change of Nuclear Configurations in the Neutrinoless Double-β Decay of 130Te → 130Xe and 136Xe → 136Ba

    DOE PAGES

    Entwisle, J. P.; Kay, B. P.; Tamii, A.; ...

    2016-06-13

    The change in the configuration of valence protons between the initial and final states in the neutrinoless double-beta decay of Te-130 -> Xe-130 and of Xe-136 -> Ba-136 has been determined by measuring the cross sections of the (d,He-3) reaction with 101-MeV deuterons. Together with our recent determination of the relevant neutron configurations involved in the process, a quantitative comparison with the latest shell-model and interacting-boson-model calculations reveals significant discrepancies. These are the same calculations used to determine the nuclear matrix elements governing the rate of neutrinoless double-beta decay in these systems.

  16. A search for double beta decays of 136Xe to the excited state of 136Ba with EXO-200

    NASA Astrophysics Data System (ADS)

    Yen, Yung-Ruey; EXO-200 Collaboration

    2015-10-01

    EXO-200 is one of the most sensitive searches for neutrinoless double beta decay of 136Xe in the world. The experiment uses 110 kg of active enriched liquid xenon in an ultralow background time projection chamber installed at the Waste Isolation Pilot Plant, a salt mine with a 1600 m water equivalent overburden. This detector has demonstrated excellent energy resolution and background rejection capabilities. While the experiment is designed to search for the double beta decays of 136Xe to the ground state of 136Ba, transitions to the excited states of 136Ba are also plausible. The ββ 2 ν decay to the first 0+ excited state of the daughter nuclei has been observed for 100Mo and 150Nd; this particular transition for 136Xe has a theoretical lifetime on the order of 1025 year, which is right around the sensitivity of EXO-200. We present the results from the search of double beta decays to the excited state using two years of EXO-200 data.

  17. Quest for Neutrinoless Double Beta Decay of 130Te with the CUORE Detector

    NASA Astrophysics Data System (ADS)

    O'Donnell, Thomas; Cuore Collaboration

    2013-10-01

    The CUORE experiment, in the advanced stages of construction at Laboratori Nazionali del Gran Sasso (LNGS), aims to search for 0 νββ decay of 130Te with unprecedented sensitivity: T1/ 2 0 ν = 9 . 5 ×1025 yr at 90 % C.L. The detector will consist of 19 towers, each comprising 13 planes of four, 125 cm3, cubic TeO2 crystals. This amounts to a total mass of 206 kg of 130Te. When cooled to an operating temperature of ~ 10 mK such crystals function as highly sensitive bolometers with energy resolution better than 5 keV demonstrated near the 0 νββ decay Q-value (2527.518 +/- 0.013 keV). In this talk I will describe the expected reach of CUORE considering the rigorous cleaning, materials handling, and ultra-pure assembly techniques developed by the collaboration. I will also report on the status of CUORE-0, a single CUORE-like tower where many of these background mitigation techniques were deployed during assembly. CUORE-0 represents a new 0 νββ experiment which is already operating at LNGS and will surpass the sensitivity of the previous generation experiment (Cuoricino) before CUORE begins operating.

  18. No-neutrino double beta decay: more than one neutrino

    SciTech Connect

    Rosen, S.P.

    1983-01-01

    Interference effects between light and heavy Majorana neutrinos in the amplitude for no-neutrino double beta decay are discussed. The effects include an upper bound on the heavy neutrino mass, and an A dependence for the effective mass extracted from double beta decay. Thus the search for the no-neutrino decay mode should be pursued in several nuclei, and particularly in Ca/sup 48/, where the effective mass may be quite large.

  19. MOON for double-beta decays and neutrino nuclear responses

    NASA Astrophysics Data System (ADS)

    Fushimi, K.; Kameda, Y.; Harada, K.; Nakayama, S.; Ejiri, H.; Shima, T.; Yasuda, K.; Hazama, R.; Imagawa, K.

    2010-01-01

    Thin and wide area inorganic crystal was tested for double beta decay experiment. The thin NaI(Tl) whose dimension of 18cm×18cm×0.5cm was developed. The energy resolution at Q-value of 100Mo was obtained less than 3% in full-width-half-maximum. Although the backscattering of electrons suffers the detection efficiency, the NaI(Tl) has the advantage for double beta decay experiment.

  20. Radiopure ZnMoO{sub 4} scintillating bolometers for the LUMINEU double-beta experiment

    SciTech Connect

    Poda, D. V.; Chernyak, D. M.; Armengaud, E.; Boissière, T. de; Fourches, N.; Gerbier, G.; Gros, M.; Hervé, S.; Magnier, P.; Navick, X-F.; Nones, C.; Paul, B.; Penichot, Y.; Arnaud, Q.; Augier, C.; Benoît, A.; Cazes, A.; Censier, B.; Charlieux, F.; De Jesus, M. [IPNL, Université de Lyon, Université Lyon 1, CNRS and others

    2015-08-17

    The results of R&D of radiopure zinc molybdate (ZnMoO{sub 4}) based scintillating bolometers for the LUMINEU (Luminescent Underground Molybdenum Investigation for NEUtrino mass and nature) double-beta decay experiment are presented. A dedicated two-stage molybdenum purification technique (sublimation in vacuum and recrystallization from aqueous solutions) and an advanced directional solidification method (the low-thermal-gradient Czochralski technique) were utilized to produce high optical quality large mass (∼1 kg) ZnMoO{sub 4} crystal boules and first {sup 100}Mo (99.5%) enriched Zn{sup 100}MoO{sub 4} crystal scintillator (mass of ∼0.2 kg). Scintillating bolometers based on ZnMoO{sub 4} (≈ 0.33 kg) and Zn{sup 100}MoO{sub 4} (≈ 0.06 kg) scintillation elements and high purity Ge wafers were tested in the EDELWEISS set-up at the Modane Underground Laboratory (France). Long term low temperature tests demonstrate excellent detectors’ performance and effectiveness of the purification and solidification procedures for the achievement of high radiopurity of the material, in particular with a bulk activity of {sup 228}Th and {sup 226}Ra below 4 µBq/kg. The adopted protocol was used to produce for the first time a large volume Zn{sup 100}MoO{sub 4} crystal scintillator (mass of ∼1.4 kg, {sup 100}Mo enrichment is 99.5%) to search for neutrinoless double-beta decay of {sup 100}Mo in the framework of the LUMINEU project.

  1. Change of Nuclear Configurations in the Neutrinoless Double-β Decay of 130Te → 130Xe and 136Xe → 136Ba

    SciTech Connect

    Entwisle, J. P.; Kay, B. P.; Tamii, A.; Adachi, S.; Aoi, N.; Clark, J. A.; Freeman, S. J.; Fujita, H.; Fujita, Y.; Furuno, T.; Hashimoto, T.; Hoffman, C. R.; Ideguchi, E.; Ito, T.; Iwamoto, C.; Kawabata, T.; Liu, B.; Miura, M.; Ong, H. J.; Schiffer, J. P.; Sharp, D. K.; Susoy, G.; Suzuki, T.; Szwec, S. V.; Takaki, M.; Tsumura, M.; Yamamoto, T.

    2016-06-13

    The change in the configuration of valence protons between the initial and final states in the neutrinoless double-beta decay of Te-130 -> Xe-130 and of Xe-136 -> Ba-136 has been determined by measuring the cross sections of the (d,He-3) reaction with 101-MeV deuterons. Together with our recent determination of the relevant neutron configurations involved in the process, a quantitative comparison with the latest shell-model and interacting-boson-model calculations reveals significant discrepancies. These are the same calculations used to determine the nuclear matrix elements governing the rate of neutrinoless double-beta decay in these systems.

  2. Computer code for double beta decay QRPA based calculations

    SciTech Connect

    Barbero, C. A.; Mariano, A.; Krmpotić, F.; Samana, A. R.; Ferreira, V. dos Santos; Bertulani, C. A.

    2014-11-11

    The computer code developed by our group some years ago for the evaluation of nuclear matrix elements, within the QRPA and PQRPA nuclear structure models, involved in neutrino-nucleus reactions, muon capture and β{sup ±} processes, is extended to include also the nuclear double beta decay.

  3. A measurement of the 2 neutrino double beta decay rate of tellurium-130 in the CUORICINO experiment

    NASA Astrophysics Data System (ADS)

    Kogler, Laura Katherine

    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 (2nubetabeta). 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 TeO2 crystals arranged in a tower and operated at a temperature of ˜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 130Te and 2 with 128Te, in order to aid in the measurement of the 2nubetabeta rate. The enriched crystals contained a total of ˜350 g 130Te. 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 2nubetabeta half-life was measured to be T1/2 = [9.81 +/- 0.96(stat) +/- 0.49(syst)] x 1020 y.

  4. Double-beta decay investigation with highly pure enriched [Formula: see text]Se for the LUCIFER experiment.

    PubMed

    Beeman, J W; Bellini, F; Benetti, P; Cardani, L; Casali, N; Chiesa, D; Clemenza, M; Dafinei, I; Domizio, S Di; Ferroni, F; Gironi, L; Giuliani, A; Gotti, C; Laubenstein, M; Maino, M; Nagorny, S; Nisi, S; Nones, C; Orio, F; Pagnanini, L; Pattavina, L; Pessina, G; Piperno, G; Pirro, S; Previtali, E; Rusconi, C; Schäffner, K; Tomei, C; Vignati, M

    The LUCIFER project aims at deploying the first array of enriched scintillating bolometers for the investigation of neutrinoless double-beta decay of [Formula: see text]Se. The matrix which embeds the source is an array of ZnSe crystals, where enriched [Formula: see text]Se is used as decay isotope. The radiopurity of the initial components employed for manufacturing crystals, that can be operated as bolometers, is crucial for achieving a null background level in the region of interest for double-beta decay investigations. In this work, we evaluated the radioactive content in 2.5 kg of 96.3 % enriched [Formula: see text]Se metal, measured with a high-purity germanium detector at the Gran Sasso deep underground laboratory. The limits on internal contaminations of primordial decay chain elements of [Formula: see text]Th, [Formula: see text]U and [Formula: see text]U are respectively: [Formula: see text]61, [Formula: see text]110 and [Formula: see text]74 [Formula: see text]Bq/kg at 90 % C.L. The extremely low-background conditions in which the measurement was carried out and the high radiopurity of the [Formula: see text]Se allowed us to establish the most stringent lower limits on the half-lives of the double-beta decay of [Formula: see text]Se to 0[Formula: see text], 2[Formula: see text] and 2[Formula: see text] excited states of [Formula: see text]Kr of 3.4[Formula: see text]10[Formula: see text], 1.3[Formula: see text]10[Formula: see text] and 1.0[Formula: see text]10[Formula: see text] y, respectively, with a 90 % C.L.

  5. Radon and material radiopurity assessment for the NEXT double beta decay experiment

    SciTech Connect

    Cebrián, S.; Dafni, T.; González-Díaz, D.; Herrera, D. C.; Irastorza, I. G.; Luzón, G.; Ortiz de Solórzano, A.; Villar, J. A.; Álvarez, V.; Cárcel, S.; Cervera, A.; Díaz, J.; Ferrario, P.; Gómez-Cadenas, J. J.; Laing, A.; Liubarsky, I.; López-March, N. [Instituto de Física Corpuscular, CSIC & Universitat de València, C and others

    2015-08-17

    The ”Neutrino Experiment with a Xenon TPC” (NEXT), intended to investigate the neutrinoless double beta decay using a high-pressure xenon gas TPC filled with Xe enriched in {sup 136}Xe at the Canfranc Underground Laboratory in Spain, requires ultra-low background conditions demanding an exhaustive control of material radiopurity and environmental radon levels. An extensive material screening process is underway for several years based mainly on gamma-ray spectroscopy using ultra-low background germanium detectors in Canfranc but also on mass spectrometry techniques like GDMS and ICPMS. Components from shielding, pressure vessel, electroluminescence and high voltage elements and energy and tracking readout planes have been analyzed, helping in the final design of the experiment and in the construction of the background model. The latest measurements carried out will be presented and the implication on NEXT of their results will be discussed. The commissioning of the NEW detector, as a first step towards NEXT, has started in Canfranc; in-situ measurements of airborne radon levels were taken there to optimize the system for radon mitigation and will be shown too.

  6. Radiopurity assessment of the tracking readout for the NEXT double beta decay experiment

    NASA Astrophysics Data System (ADS)

    Cebrián, S.; Pérez, J.; Bandac, I.; Labarga, L.; Álvarez, V.; Barrado, A. I.; Bettini, A.; Borges, F. I. G. M.; Camargo, M.; Cárcel, S.; Cervera, A.; Conde, C. A. N.; Conde, E.; Dafni, T.; Díaz, J.; Esteve, R.; Fernandes, L. M. P.; Fernández, M.; Ferrario, P.; Ferreira, A. L.; Freitas, E. D. C.; Gehman, V. M.; Goldschmidt, A.; Gómez-Cadenas, J. J.; González-Díaz, D.; Gutiérrez, R. M.; Hauptman, J.; Hernando Morata, J. A.; Herrera, D. C.; Irastorza, I. G.; Laing, A.; Liubarsky, I.; López-March, N.; Lorca, D.; Losada, M.; Luzón, G.; Marí, A.; Martín-Albo, J.; Martínez, A.; Martínez-Lema, G.; Miller, T.; Monrabal, F.; Monserrate, M.; Monteiro, C. M. B.; Mora, F. J.; Moutinho, L. M.; Muñoz Vidal, J.; Nebot-Guinot, M.; Nygren, D.; Oliveira, C. A. B.; Ortiz de Solórzano, A.; Pérez Aparicio, J. L.; Querol, M.; Renner, J.; Ripoll, L.; Rodríguez, J.; Santos, F. P.; dos Santos, J. M. F.; Serra, L.; Shuman, D.; Simón, A.; Sofka, C.; Sorel, M.; Toledo, J. F.; Torrent, J.; Tsamalaidze, Z.; Veloso, J. F. C. A.; Villar, J. A.; Webb, R. C.; White, J. T.; Yahlali, N.

    2015-05-01

    The ``Neutrino Experiment with a Xenon Time-Projection Chamber'' (NEXT) is intended to investigate the neutrinoless double beta decay of 136Xe, which requires a severe suppression of potential backgrounds; therefore, an extensive screening and selection process is underway to control the radiopurity levels of the materials to be used in the experimental set-up of NEXT. The detector design combines the measurement of the topological signature of the event for background discrimination with the energy resolution optimization. Separate energy and tracking readout planes are based on different sensors: photomultiplier tubes for calorimetry and silicon multi-pixel photon counters for tracking. The design of a radiopure tracking plane, in direct contact with the gas detector medium, was specially challenging since the needed components like printed circuit boards, connectors, sensors or capacitors have typically, according to available information in databases and in the literature, activities too large for experiments requiring ultra-low background conditions. Here, the radiopurity assessment of tracking readout components based on gamma-ray spectroscopy using ultra-low background germanium detectors at the Laboratorio Subterr&aposaneo de Canfranc (Spain) is described. According to the obtained results, radiopure enough printed circuit boards made of kapton and copper, silicon photomultipliers and other required components, fulfilling the requirement of an overall background level in the region of interest of at most 8×10-4 counts keV-1 kg-1 y-1, have been identified.

  7. Radon and material radiopurity assessment for the NEXT double beta decay experiment

    NASA Astrophysics Data System (ADS)

    Cebrián, S.; Pérez, J.; Bandac, I.; Labarga, L.; Álvarez, V.; Barrado, A. I.; Bettini, A.; Borges, F. I. G. M.; Camargo, M.; Cárcel, S.; Cervera, A.; Conde, C. A. N.; Conde, E.; Dafni, T.; Díaz, J.; Esteve, R.; Fernandes, L. M. P.; Fernández, M.; Ferrario, P.; Freitas, E. D. C.; Fernandes, L. M. P.; Gehman, V. M.; Goldschmidt, A.; Gómez-Cadenas, J. J.; González-Díaz, D.; Gutiérrez, R. M.; Hauptman, J.; Morata, J. A. Hernando; Herrera, D. C.; Irastorza, I. G.; Laing, A.; Liubarsky, I.; López-March, N.; Lorca, D.; Losada, M.; Luzón, G.; Marí, A.; Martín-Albo, J.; Martínez, A.; Martínez-Lema, G.; Miller, T.; Monrabal, F.; Monserrate, M.; Monteiro, C. M. B.; Mora, F. J.; Moutinho, L. M.; Vidal, J. Muñoz; Nebot-Guinot, M.; Nygren, D.; Oliveira, C. A. B.; de Solórzano, A. Ortiz; Aparicio, J. L. Pérez; Querol, M.; Renner, J.; Ripoll, L.; Rodríguez, J.; Santos, F. P.; dos Santos, J. M. F.; Serra, L.; Shuman, D.; Simón, A.; Sofka, C.; Sorel, M.; Toledo, J. F.; Torrent, J.; Tsamalaidze, Z.; Veloso, J. F. C. A.; Villar, J. A.; Webb, R. C.; White, J. T.; Yahlali, N.

    2015-08-01

    The "Neutrino Experiment with a Xenon TPC" (NEXT), intended to investigate the neutrinoless double beta decay using a high-pressure xenon gas TPC filled with Xe enriched in 136Xe at the Canfranc Underground Laboratory in Spain, requires ultra-low background conditions demanding an exhaustive control of material radiopurity and environmental radon levels. An extensive material screening process is underway for several years based mainly on gamma-ray spectroscopy using ultra-low background germanium detectors in Canfranc but also on mass spectrometry techniques like GDMS and ICPMS. Components from shielding, pressure vessel, electroluminescence and high voltage elements and energy and tracking readout planes have been analyzed, helping in the final design of the experiment and in the construction of the background model. The latest measurements carried out will be presented and the implication on NEXT of their results will be discussed. The commissioning of the NEW detector, as a first step towards NEXT, has started in Canfranc; in-situ measurements of airborne radon levels were taken there to optimize the system for radon mitigation and will be shown too.

  8. Majorana Neutrino Masses by Spectroscopic Studies of Double Beta Decays and Moon

    NASA Astrophysics Data System (ADS)

    Ejiri, Hiroyasu

    This is a brief review of spectroscopic studies of neutrino-less double beta decays (0νββ) and the MOON (Mo Observatory Of Neutrinos) project. It aims at studying the Majorana nature of neutrinos and the mass spectrum by spectroscopic studies of 0νββ with ν-mass sensitivity of ≈ 30 meV. The solid scintillator option of the MOON detector is a super ensemble of multi-layer modules, each being composed by a scintillator plate and two tracking detector planes. Thin ββ source films are interleaved between the detector planes. High localization of the two β tracks enables one to select true signals and reject BG ones by spatial and time correlation analyses. MOON with detector ≠ ββ source is used for studying 0νββ decays from 100Mo, 82Se and other ββ isotopes with large nuclear sensitivity (large Qββ). Real-time exclusive measurements of low energy solar neutrinos can also be made by observing inverse β rays from solar-ν captures of 100Mo in delayed coincidence with the subsequent β decay of 100Tc.

  9. First NEXT prototypes for double-beta decay search

    NASA Astrophysics Data System (ADS)

    Yahlali, Nadia; Irastorza, Igor G.; NEXT Collaboration

    2011-02-01

    The NEXT collaboration aims at building a 100 kg high-pressure Xenon gas TPC enriched in 136Xe isotope, to measure its two double-beta decay modes and to explore the degenerate hierarchy of the neutrino mass. The high-pressure Xenon gas offers the possibility to record the event energy with near-intrinsic resolution using electroluminescence, as well as the event track and topology patterns. These are the key features of a robust double-beta decay experiment which are presently being investigated in the first NEXT prototypes, the so-called NEXT0 and NEXT1. In this paper, the prototypes being developed at IFIC and University of Zaragoza are described and preliminary results are outlined.

  10. MeV neutrinos in double {beta} decay

    SciTech Connect

    Zuber, K.

    1997-08-01

    The effect of Majorana neutrinos in the MeV mass range on the double {beta} decay of various isotopes is studied on pure phenomenological arguments. By using only experimental half-life data, limits on the mixing parameter U{sub eh}{sup 2} of the order 10{sup {minus}7} can be derived. Also the possible achievements of upcoming experiments and some consequences are outlined. {copyright} {ital 1997} {ital The American Physical Society}

  11. Influence of Pairing on the Nuclear Matrix Elements of the Neutrinoless {beta}{beta} Decays

    SciTech Connect

    Caurier, E.; Nowacki, F.

    2008-02-08

    We study in this Letter the neutrinoless double beta decay nuclear matrix elements (NME's) in the framework of the interacting shell model. We analyze them in terms of the total angular momentum of the decaying neutron pair and as a function of the seniority truncations in the nuclear wave functions. This point of view turns out to be very adequate to gauge the accuracy of the NME's predicted by different nuclear models. In addition, it gives back the protagonist role in this process to the pairing interaction, the one which is responsible for the very existence of double beta decay emitters. We show that low seniority approximations, comparable to those implicit in the quasiparticle RPA in a spherical basis, tend to overestimate the NME's in several decays.

  12. Values of the phase space factors for double beta decay

    SciTech Connect

    Stoica, Sabin Mirea, Mihai

    2015-10-28

    We report an up-date list of the experimentally most interesting phase space factors for double beta decay (DBD). The electron/positron wave functions are obtained by solving the Dirac equations with a Coulomb potential derived from a realistic proton density distribution in nucleus and with inclusion of the finite nuclear size (FNS) and electron screening (ES) effects. We build up new numerical routines which allow us a good control of the accuracy of calculations. We found several notable differences as compared with previous results reported in literature and possible sources of these discrepancies are discussed.

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

    SciTech Connect

    Kogler, Laura K.

    2011-11-30

    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 (2vββ). 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 TeO2 crystals arranged in a tower and operated at a temperature of 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 130Te and 2 with 128Te, in order to aid in the measurement of the 2vββ rate. The enriched crystals contained a total of 350 g 130Te. 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 2vββ half-life was measured to be T2v1/2 = [9.81± 0.96(stat)± 0.49(syst)] x1020 y.

  14. Evaluation of radioactive background rejection in 76Ge neutrino-lessdouble-beta decay experiments using a highly segmented HPGe detector

    SciTech Connect

    Chan, Yuen-Dat; Campbell, D.B.; Vetter, K.; Henning, R.; Lesko, K.; Chan, Y.D.; Poon, A.W.P.; Perry, M.; Hurley, D.; Smith, A.R.

    2007-02-05

    A highly segmented coaxial HPGe detector was operated in a low background counting facility for over 1 year to experimentally evaluate possible segmentation strategies for the proposed Majorana neutrino-less double-beta decay experiment. Segmentation schemes were evaluated on their ability to reject multi-segment events while retaining single-segment events. To quantify a segmentation scheme's acceptance efficiency the percentage of peak area due to single segment events was calculated for peaks located in the energy region 911-2614 keV. Single interaction site events were represented by the double-escape peak from the 2614 keV decay in {sup 208}Tl located at 1592 keV. In spite of its prototypical nature, the detector performed well under realistic operating conditions and required only minimal human interaction. Though the energy resolution for events with interactions in multiple segments was impacted by inter-segment cross-talk, the implementation of a cross-talk correlation matrix restored acceptable resolution. Additionally, simulations utilizing the MaGe simulation package were performed and found to be in good agreement with experimental observations verifying the external nature of the background radiation.

  15. MOON (Mo Observatory Of Neutrinos) for double beta decay

    NASA Astrophysics Data System (ADS)

    Nomachi, M.; Doe, P.; Ejiri, H.; Elliott, S. R.; Engel, J.; Finger, M.; Formaggio, J. A.; Fushimi, K.; Gehman, V.; Gorin, A.; Greenfield, M.; Hazama, R.; Ichihara, K.; Ikegami, Y.; Ishii, H.; Itahashi, T.; Kavitov, P.; Kekelidze, V.; Kuroda, K.; Kutsalo, V.; Manouilov, I.; Matsuoka, K.; Nakamura, H.; Ogama, T.; Para, A.; Rielage, K.; Rjazantsev, A.; Robertson, R. G. H.; Shichijo, Y.; Shima, T.; Shimada, Y.; Shirkov, G.; Sissakian, A.; Sugaya, Y.; Titov, A.; Vatulin, V.; Vilches, O. E.; Voronov, V.; Wilkerson, J. F.; Will, D. I.; Yoshida, S.

    2005-01-01

    The MOON (Molybdenum Observatory Of Neutrinos) project aims at studies of double beta decays with a high sensitivity of ˜0.03 eV and real-time studies of low-energy solar neutrinos. Two β rays from 100Mo are measured in coincidence for the 0νββ studies. The inverse β rays from solar neutrino captures of 100Mo are measured in delayed coincidence with the following β decay of 100Tc. Measurements with good energy resolution and good position resolution enable one to select true signals. A prototype MOON detector (MOON 1) is now under development. The present report describes briefly the outline of the MOON project and the status of MOON 1.

  16. On improvements of Double Beta Decay using FQTDA Model

    NASA Astrophysics Data System (ADS)

    de Oliveira, L.; Samana, A. R.; Krmpotic, F.; Mariano, A. E.; Barbero, C. A.

    2015-07-01

    The Quasiparticle Tamm-Dancoff Approximation (QTDA) is applied to describe the nuclear double beta decay with two neutrinos. Several serious inconveniences found in the Quasiparticle Random Phase Approximation (QRPA) are not present in the QTDA, as such as the ambiguity in treating the intermediary states, and further approximations necessary for evaluation of the nuclear matrix elements (NMEs) or, the extreme sensitivity of NME with the ratio between the pn and pp + nn pairings. Some years ago, the decay 48Ca → 48Ti was discussed within the particle-hole limit of QTDA. We found some mismatch in the numerical calculations when the full QTDA was being implemented, and a new performance in the particle-hole limit of QTDA is required to guarantee the fidelity of the approximation.

  17. Search for Majoron-emitting modes of double-beta decay of Xe 136 with EXO-200

    NASA Astrophysics Data System (ADS)

    Albert, J. B.; Auty, D. J.; Barbeau, P. S.; Beauchamp, E.; Beck, D.; Belov, V.; Benitez-Medina, C.; Breidenbach, M.; Brunner, T.; Burenkov, A.; Cao, G. F.; Chambers, C.; Chaves, J.; Cleveland, B.; Coon, M.; Craycraft, A.; Daniels, T.; Danilov, M.; Daugherty, S. J.; Davis, C. G.; Davis, J.; DeVoe, R.; Delaquis, S.; Didberidze, T.; Dolgolenko, A.; Dolinski, M. J.; Dunford, M.; Fairbank, W.; Farine, J.; Feldmeier, W.; Fierlinger, P.; Fudenberg, D.; Giroux, G.; Gornea, R.; Graham, K.; Gratta, G.; Hall, C.; Herrin, S.; Hughes, M.; Jewell, M. J.; Jiang, X. S.; Johnson, A.; Johnson, T. N.; Johnston, S.; Karelin, A.; Kaufman, L. J.; Killick, R.; Koffas, T.; Kravitz, S.; Kuchenkov, A.; Kumar, K. S.; Leonard, D. S.; Leonard, F.; Licciardi, C.; Lin, Y. H.; Ling, J.; MacLellan, R.; Marino, M. G.; Mong, B.; Moore, D.; Nelson, R.; Odian, A.; Ostrovskiy, I.; Ouellet, C.; Piepke, A.; Pocar, A.; Prescott, C. Y.; Rivas, A.; Rowson, P. C.; Rozo, M. P.; Russell, J. J.; Schubert, A.; Sinclair, D.; Smith, E.; Stekhanov, V.; Tarka, M.; Tolba, T.; Tosi, D.; Tsang, R.; Twelker, K.; Vogel, P.; Vuilleumier, J.-L.; Waite, A.; Walton, J.; Walton, T.; Weber, M.; Wen, L. J.; Wichoski, U.; Yang, L.; Yen, Y.-R.; Zeldovich, O. Ya.; EXO-200 Collaboration

    2014-11-01

    EXO-200 is a single phase liquid xenon detector designed to search for neutrinoless double-beta decay of Xe 136 . Here, we report on a search for various Majoron-emitting modes based on 100 kg yr exposure of Xe 136 . A lower limit of T1/2 Xe 136 >1.2 ×1024 yr at 90% C.L. on the half-life of the spectral index =1 Majoron decay was obtained, corresponding to a constraint on the Majoron-neutrino coupling constant of |⟨gee M⟩|<(0.8 - 1.7 )×10-5 .

  18. Improving the physics impact of next-generation 76Ge neutrinoless double-beta decay experiments

    SciTech Connect

    Hossbach, Todd W.

    2009-01-01

    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.

  19. Final Technical Report [Cosmogenic background and shielding R&D for a Ge Neutrinoless Double Beta Decay Experiment

    SciTech Connect

    Guiseppe, Vince

    2013-10-01

    The USD Majorana group focused all of its effort in support of the MAJORANA DEMONSTRATOR (MJD) experiment. Final designs of the shielding subsystems are complete. Construction of the MJD shielding systems at SURF has begun and the proposed activities directly support the completion of the shield systems. The PI and the group contribute heavily to the onsite construction activities of the MJD experiment. The group led investigations into neutron and neutron-­induced backgrounds, shielding effectiveness and design, and radon backgrounds.

  20. Simulation studies of muon-produced background events deep underground and consequences for double beta decay experiments

    NASA Astrophysics Data System (ADS)

    Massarczyk, Ralph; Majorana Collaboration

    2015-10-01

    Cosmic radiation creates a significant background for low count rate experiments. The Majorana demonstrator experiment is located at the Sanford Underground Research Facility at a depth of 4850ft below the surface but it can still be penetrated by cosmic muons with initial energies above the TeV range. The interaction of muons with the rock, the shielding material in the lab and the detector itself can produce showers of secondary particles, like fast neutrons, which are able to travel through shielding material and can produce high-energy γ-rays via capture or inelastic scattering. The energy deposition of these γ rays in the detector can overlap with energy region of interest for the neutrino-less double beta decay. Recent studies for cosmic muons penetrating the Majorana demonstrator are made with the Geant4 code. The results of these simulations will be presented in this talk and an overview of the interaction of the shower particles with the detector, shielding and veto system will be given. This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics, the Particle Astrophysics Program of the National Science Foundation, and the Sanford Underground Research Facility. Supported by U.S. Department of Energy through the LANL/LDRD Program.

  1. Radon emanation based material measurement and selection for the SuperNEMO double beta experiment

    SciTech Connect

    Cerna, Cédric Soulé, Benjamin; Perrot, Frédéric

    2015-08-17

    The SuperNEMO Demonstrator experiment aims to study the neutrinoless double beta decay of 7 kg of {sup 82}Se in order to reach a limit on the light Majorana neutrino mass mechanism T{sub 1/2} (ββ0ν) > 6.5 10{sup 24} years (90%CL) equivalent to a mass sensitivity mβ{sub β} < 0.20 - 0.40 eV (90%CL) in two years of data taking. The detector construction started in 2014 and its installation in the Laboratoire Souterrain de Modane (LSM) is expected during the course of 2015. The remaining level of {sup 226}Ra ({sup 238}U chain) in the detector components can lead to the emanation of {sup 222}Rn gas. This isotope should be controlled and reduced down to the level of a 150 µBq/m{sup 3} in the tracker chamber of the detector to achieve the physics goals. Besides the HPGe selection of the detector materials for their radiopurity, the most critical materials have been tested and selected in a dedicated setup facility able to measure their {sup 222}Rn emanation level. The operating principle relies on a large emanation tank (0.7m{sup 3}) that allows measuring large material surfaces or large number of construction pieces. The emanation tank is coupled to an electrostatic detector equipped with a silicon diode to perform the alpha spectroscopy of the gas it contains and extract the {sup 222}Rn daughters. The transfer efficiency and the detector efficiency have been carefully calibrated through different methods. The intrinsic background of the system allows one to measure 222Rn activities down to 3 mBq, leading to a typical emanation sensitivity of 20 µBq/m{sup 2}/day for a 30 m{sup 2} surface sample. Several construction materials have been measured and selected, such as nylon and aluminized Mylar films, photomultipliers and tracking of the SuperNEMO Demonstrator.

  2. Purification of lanthanides for double beta decay experiments

    NASA Astrophysics Data System (ADS)

    Polischuk, O. G.; Barabash, A. S.; Belli, P.; Bernabei, R.; Boiko, R. S.; Cappella, F.; Cerulli, R.; Danevich, F. A.; Incicchitti, A.; Laubenstein, M.; Mokina, V. M.; Nisi, S.; Poda, D. V.; Tretyak, V. I.

    2013-08-01

    There are several potentially double beta active isotopes among the lanthanide elements. However, even high purity grade lanthanide compounds contain 238U, 226Ra and 232,228Th typically on the level of ˜ (0.1 - 1) Bq/kg. The liquid-liquid extraction technique was used to remove traces of U, Ra and Th from CeO2, Nd2O3 and Gd2O3. The radioactive contamination of the samples before and after the purification was tested by using ultra-low-background HPGe γ spectrometry at the underground Gran Sasso National Laboratories of the INFN (Italy). After the purification the radioactive contamination of gadolinium oxide by Ra and Th was decreased at least one order of magnitude. The efficiency of the approach to purify cerium oxide from Ra was on same level, while the radioactive contamination of neodymium sample before and after the purification is below the sensitivity of analytical methods. The purification method is much less efficient for chemically very similar radioactive elements like lanthanum, lutetium and actinium. R&D of the methods to remove the pollutions with improved efficiency is in progress.

  3. Purification of lanthanides for double beta decay experiments

    SciTech Connect

    Polischuk, O. G.; Barabash, A. S.; Belli, P.; Bernabei, R.; Boiko, R. S.; Danevich, F. A.; Mokina, V. M.; Poda, D. V.; Tretyak, V. I.; Cappella, F.; Incicchitti, A.; Cerulli, R.; Laubenstein, M.; Nisi, S.

    2013-08-08

    There are several potentially double beta active isotopes among the lanthanide elements. However, even high purity grade lanthanide compounds contain {sup 238}U, {sup 226}Ra and {sup 232,228}Th typically on the level of ∼ (0.1 - 1) Bq/kg. The liquid-liquid extraction technique was used to remove traces of U, Ra and Th from CeO{sub 2}, Nd{sub 2}O{sub 3} and Gd{sub 2}O{sub 3}. The radioactive contamination of the samples before and after the purification was tested by using ultra-low-background HPGe γ spectrometry at the underground Gran Sasso National Laboratories of the INFN (Italy). After the purification the radioactive contamination of gadolinium oxide by Ra and Th was decreased at least one order of magnitude. The efficiency of the approach to purify cerium oxide from Ra was on same level, while the radioactive contamination of neodymium sample before and after the purification is below the sensitivity of analytical methods. The purification method is much less efficient for chemically very similar radioactive elements like lanthanum, lutetium and actinium. R and D of the methods to remove the pollutions with improved efficiency is in progress.

  4. The Majorana Experiment

    SciTech Connect

    Aalseth, Craig E.; Aguayo Navarrete, Estanislao; Amman, M.; Avignone, F. T.; Back, Henning O.; Bai, Xinhua; Barabash, Alexander S.; Barbeau, P. S.; Bergevin, M.; Bertrand, F.; Boswell, M.; Brudanin, V.; Bugg, William; Burritt, Tom H.; Busch, Matthew; Capps, Greg L.; Chan, Yuen-Dat; Collar, J. I.; Cooper, R. J.; Creswick, R.; Detwiler, Jason A.; Diaz, J.; Doe, Peter J.; Efremenko, Yuri; Egorov, Viatcheslav; Ejiri, H.; Elliott, S. R.; Ely, James H.; Esterline, James H.; Farach, H. A.; Fast, James E.; Fields, N.; Finnerty, P.; Fraenkle, Florian; Gehman, Victor M.; Giovanetti, G. K.; Green, M.; Guiseppe, Vincente; Gusey, K.; Hallin, A. L.; Harper, Gregory; Hazama, R.; Henning, Reyco; Hime, Andrew; Hong, H.; Hoppe, Eric W.; Hossbach, Todd W.; Howard, Stanley; Howe, M. A.; Johnson, R. A.; Keeter, K.; Keillor, Martin E.; Keller, C.; Kephart, Jeremy D.; Kidd, M. F.; Knecht, A.; Kochetov, Oleg; Konovalov, S.; Kouzes, Richard T.; LaRoque, B. H.; Leviner, L.; Loach, J. C.; Luke, P.; MacMullin, S.; Marino, Michael G.; Martin, R. D.; Medlin, D.; Mei, Dong-Ming; Miley, Harry S.; Miller, M. L.; Mizouni, Leila; Myers, Allan W.; Nomachi, Masaharu; Orrell, John L.; Peterson, David; Phillips, D.; Poon, Alan; Perevozchikov, O.; Perumpilly, Gopakumar; Prior, Gersende; Radford, D. C.; Reid, Douglas J.; Rielage, Keith; Robertson, R. G. H.; Rodriguez, Larry; Ronquest, M. C.; Salazar, Harold; Schubert, Alexis G.; Shima, T.; Shirchenko, M.; Sobolev, V.; Steele, David; Strain, J.; Swift, Gary; Thomas, K.; Timkin, V.; Tornow, W.; Van Wechel, T. D.; Vanyushin, I.; Varner, R. L.; Vetter, Kai; Vorren, Kris R.; Wilkerson, J. F.; Wolfe, B. A.; Xiang, W.; Yakushev, E.; Yaver, Harold; Young, A.; Yu, Chang-Hong; Yumatov, V.; Zhang, C.

    2011-08-01

    The Majorana Collaboration is assembling an array of HPGe detectors to search for neutrinoless double-beta decay in 76Ge. Initially, Majorana aims to construct a prototype module to demonstrate the potential of a future 1-tonne experiment. The design and potential reach of this prototype Demonstrator module are presented.

  5. Ageing studies of TPB in noble gas detectors for dark matter and neutrinoless ββ decay searches.

    PubMed

    Yahlali, N; Garcia, J M; Díaz, J; Soriano, A; Fernandes, L M P

    2017-02-05

    Noble gases (Xe, Ar, Kr) are very attractive as detector media in Dark Matter search and neutrinoless double-beta decay experiments. However, the detection of their scintillation light (in the VUV spectral region) requires shifting the VUV light to visible light, where standard photosensors are more efficient. Tetraphenyl butadiene (TPB) is widely used as wavelength shifter, absorbing the VUV light and re-emitting in the blue region (~430nm). TPB is an organic molecule that may degrade due to exposure to environmental agents and also to ultraviolet light. In this work, we present TPB ageing studies due to exposure to VUV light, aiming at quantifying the reduction of the absolute fluorescence yield of TPB coatings of several thicknesses (130nm, 260nm, 390nm, 1600nm), exposed to various doses of VUV light at 170nm (similar to the Xe scintillation). In our setup, the VUV light is produced from a vacuum monochromator coupled to a deuterium lamp. The VUV exposure in our setup is compared to the exposure obtained in the electroluminescent gaseous Xe TPC of the NEXT-100 experiment for neutrinoless double-beta decay search.

  6. Ageing studies of TPB in noble gas detectors for dark matter and neutrinoless ββ decay searches

    NASA Astrophysics Data System (ADS)

    Yahlali, N.; Garcia, J. M.; Díaz, J.; Soriano, A.; Fernandes, L. M. P.

    2017-02-01

    Noble gases (Xe, Ar, Kr) are very attractive as detector media in Dark Matter search and neutrinoless double-beta decay experiments. However, the detection of their scintillation light (in the VUV spectral region) requires shifting the VUV light to visible light, where standard photosensors are more efficient. Tetraphenyl butadiene (TPB) is widely used as wavelength shifter, absorbing the VUV light and re-emitting in the blue region ( 430 nm). TPB is an organic molecule that may degrade due to exposure to environmental agents and also to ultraviolet light. In this work, we present TPB ageing studies due to exposure to VUV light, aiming at quantifying the reduction of the absolute fluorescence yield of TPB coatings of several thicknesses (130 nm, 260 nm, 390 nm, 1600 nm), exposed to various doses of VUV light at 170 nm (similar to the Xe scintillation). In our setup, the VUV light is produced from a vacuum monochromator coupled to a deuterium lamp. The VUV exposure in our setup is compared to the exposure obtained in the electroluminescent gaseous Xe TPC of the NEXT-100 experiment for neutrinoless double-beta decay search.

  7. Confirmation of the observation of 2v ββ decay of 76Ge

    NASA Astrophysics Data System (ADS)

    Avignone, F. T.; Brodzinski, R. L.; Guerard, C. K.; Kirpichnikov, I. V.; Miley, H. S.; Pogosov, V. S.; Reeves, J. H.; Starostin, A. S.; Tamanyan, A. G.

    1991-03-01

    Two previous independent reports of 2v ββ decay by the ITEP-YPI Collaboration, T {1}/{2}2 v = (9±1) × 10 20yr (1σ) , and the PNL-USC Collaboration, T {1}/{2}2 v = (1.12 -0.26+0.48) × 10 21yr (2σ) , are confirmed. A 0.25 kg Ge(Li) detector, isotopically enriched to 85% in 76Ge, was operated in the PNL-USC ultralow-background facility in the Homestake gold mine. Following a single correction to the data, a spectrum resembling that observed in the earlier PNL-USC experiment, with about the same intensity per 76Ge atom per year, was observed. The measured half-life is T {1}/{2}2 v = (9.2 -0.4+0.7) × 10 20yr (2σ) .

  8. Shape coexistence and the role of axial asymmetry in 72,76Ge

    NASA Astrophysics Data System (ADS)

    Ayangeakaa, A. D.; Janssens, R. V. F.; Wu, C. Y.; Allmond, J. M.; Wood, J. L.; Zhu, S.; Albers, M.; Almaraz-Calderon, S.; Bucher, B.; Carpenter, M. P.; Chiara, C. J.; Cline, D.; Crawford, H. L.; David, H. M.; Harker, J.; Hayes, A. B.; Hoffman, C. R.; Kay, B. P.; Kolos, K.; Korichi, A.; Lauritsen, T.; Macchiavelli, A. O.; Richards, A.; Seweryniak, D.; Wiens, A.

    2016-09-01

    The structure of low-lying states in medium-mass germanium isotopes 72Ge and 76Ge is investigated via projectile Coulomb excitation with GRETINA and CHICO2. In both nuclei, complete sets of E 2 matrix elements were determined and substantial evidence for triaxiality and shape coexistence, based on the model-independent shape invariants deduced from the Kumar-Cline sum rule, has been observed [3]. These observations are supported by results of a two-state mixing model as well as multi-configuration mixing calculations carried out within the framework of the triaxial rotor model. These observations and the role of axial asymmetry in the shape coexistence phenomena, as well as results pertaining to rigid triaxiality in 76Ge will be presented. Department of Energy, Office of Science, Office of Nuclear Physics and the National Science Foundation.

  9. Experimental study of double-{beta} decay modes using a CdZnTe detector array

    SciTech Connect

    Dawson, J. V.; Goessling, C.; Koettig, T.; Muenstermann, D.; Rajek, S.; Schulz, O.; Janutta, B.; Zuber, K.; Junker, M.; Reeve, C.; Wilson, J. R.

    2009-08-15

    An array of sixteen 1 cm{sup 3} CdZnTe semiconductor detectors was operated at the Gran Sasso Underground Laboratory (LNGS) to further investigate the feasibility of double-{beta} decay searches with such devices. As one of the double-{beta} decay experiments with the highest granularity the 4x4 array accumulated an overall exposure of 18 kg days. The setup and performance of the array is described. Half-life limits for various double-{beta} decay modes of Cd, Zn, and Te isotopes are obtained. No signal has been found, but several limits beyond 10{sup 20} years have been performed. They are an order of magnitude better than those obtained with this technology before and comparable to most other experimental approaches for the isotopes under investigation. An improved limit for the {beta}{sup +}/EC decay of {sup 120}Te is given.

  10. About some of the theoretical approaches used in double-beta decay calculations

    SciTech Connect

    Civitarese, O.

    2007-10-12

    The calculations of nuclear matrix elements, corresponding to nuclear double beta decay transitions, rely upon several approximations. The impact of these approximations upon final estimations of the nuclear matrix elements is illustrated. We pay attention to mean field (symmetry violations) and to approximate diagonalizations (pn-QRPA, renormalized pn-QRPA and fully renormalized pn-QRPA)

  11. About some of the theoretical approaches used in double-beta decay calculations

    NASA Astrophysics Data System (ADS)

    Civitarese, O.

    2007-10-01

    The calculations of nuclear matrix elements, corresponding to nuclear double beta decay transitions, rely upon several approximations. The impact of these approximations upon final estimations of the nuclear matrix elements is illustrated. We pay attention to mean field (symmetry violations) and to approximate diagonalizations (pn-QRPA, renormalized pn-QRPA and fully renormalized pn-QRPA).

  12. First search for Lorentz and C P T violation in double beta decay with EXO-200

    NASA Astrophysics Data System (ADS)

    Albert, J. B.; Barbeau, P. S.; Beck, D.; Belov, V.; Breidenbach, M.; Brunner, T.; Burenkov, A.; Cao, G. F.; Chambers, C.; Cleveland, B.; Coon, M.; Craycraft, A.; Daniels, T.; Danilov, M.; Daugherty, S. J.; Davis, C. G.; Davis, J.; Delaquis, S.; Der Mesrobian-Kabakian, A.; DeVoe, R.; Díaz, J. S.; Didberidze, T.; Dilling, J.; Dolgolenko, A.; Dolinski, M. J.; Dunford, M.; Fairbank, W.; Farine, J.; Feyzbkhsh, S.; Feldmeier, W.; Fierlinger, P.; Fudenberg, D.; Gornea, R.; Graham, K.; Gratta, G.; Hall, C.; Homiller, S.; Hughes, M.; Jewell, M. J.; Jiang, X. S.; Johnson, A.; Johnson, T. N.; Johnston, S.; Karelin, A.; Kaufman, L. J.; Killick, R.; Koffas, T.; Kravitz, S.; Krücken, R.; Kuchenkov, A.; Kumar, K. S.; Leonard, D. S.; Licciardi, C.; Lin, Y. H.; Ling, J.; MacLellan, R.; Marino, M. G.; Mong, B.; Moore, D.; Nelson, R.; Njoya, O.; Odian, A.; Ostrovskiy, I.; Piepke, A.; Pocar, A.; Prescott, C. Y.; Retiére, F.; Rowson, P. C.; Russell, J. J.; Schubert, A.; Sinclair, D.; Smith, E.; Stekhanov, V.; Tarka, M.; Tolba, T.; Tsang, R.; Twelker, K.; Vuilleumier, J.-L.; Vogel, P.; Waite, A.; Walton, J.; Walton, T.; Weber, M.; Wen, L. J.; Wichoski, U.; Wood, J.; Yang, L.; Yen, Y.-R.; Zeldovich, O. Ya.; EXO-200 Collaboration

    2016-04-01

    A search for Lorentz- and C P T -violating signals in the double beta decay spectrum of 136Xe has been performed using an exposure of 100 kg .yr with the EXO-200 detector. No significant evidence of the spectral modification due to isotropic Lorentz-violation was found, and a two-sided limit of -2.65 ×10-5 GeV <âof(3 )<7.60 ×10-6 GeV (90% C.L.) is placed on the relevant coefficient within the Standard-Model Extension (SME). This is the first experimental study of the effect of the SME-defined oscillation-free and momentum-independent neutrino coupling operator on the double beta decay process.

  13. Nuclear structure of 76Ge from inelastic neutron scattering measurements and shell model calculations

    NASA Astrophysics Data System (ADS)

    Mukhopadhyay, S.; Crider, B. P.; Brown, B. A.; Ashley, S. F.; Chakraborty, A.; Kumar, A.; McEllistrem, M. T.; Peters, E. E.; Prados-Estévez, F. M.; Yates, S. W.

    2017-01-01

    The low-lying, low-spin levels of 76Ge were studied with the (n ,n'γ ) reaction. Gamma-ray excitation function measurements were performed at incident neutron energies from 1.6 to 3.7 MeV, and γ -ray angular distributions were measured at neutron energies of 3.0 and 3.5 MeV. From these measurements, level spins, level lifetimes, γ -ray intensities, and multipole mixing ratios were determined. No evidence for a number of previously placed levels was found. Below 3.3 MeV, many new levels were identified, and the level scheme was re-evaluated. The B (E 2 ) values support low-lying band structure. The 2+ mixed-symmetry state has been identified for the first time. A comparison of the level characteristics with large-scale shell model calculations yielded excellent agreement.

  14. The MAJORANA DEMONSTRATOR for 0νββ: Current Status and Future Plans

    SciTech Connect

    Green, M. P.; Abgrall, N.; Aguayo, Estanislao; Avignone, Frank T.; Barabash, Alexander; Bertrand, F.; Boswell, M.; Brudanin, V.; Busch, Matthew; Byram, D.; Caldwell, A. S.; Chan, Yuen-Dat; Christofferson, Cabot-Ann; Combs, Dustin C.; Cuesta, C.; Detwiler, Jason A.; Doe, P. J.; Efremenko, Yuri; Egorov, Viatcheslav; Ejiri, H.; Elliott, S. R.; Fast, James E.; Finnerty, P.; Fraenkle, Florian; Galindo-Uribarri, A.; Giovanetti, G. K.; Goett, J.; Gruszko, J.; Guiseppe, Vincente; Gusev, K.; Hallin, A. L.; Hazama, R.; Hegai, A.; Henning, Reyco; Hoppe, Eric W.; Howard, Stanley; Howe, M. A.; Keeter, K.; Kidd, M. F.; Kochetov, Oleg; Konovalov, S.; Kouzes, Richard T.; Laferriere, Brian D.; Leon, Jonathan D.; Leviner, L.; Loach, J. C.; MacMullin, J.; MacMullin, S.; Martin, R. D.; Meijer, S. J.; Mertens, S.; Nomachi, Masaharu; Orrell, John L.; O'Shaughnessy, Mark D.; Overman, Nicole R.; Phillips, David; Poon, Alan; Pushkin, K.; Radford, D. C.; Rager, J.; Rielage, Keith; Robertson, R. G. H.; Romero-Romero, E.; Ronquest, M. C.; Schubert, Alexis G.; Shanks, B.; Shima, T.; Shirchenko, M.; Snavely, Kyle J.; Snyder, N.; Suriano, Anne-Marie; Thompson, J.; Timkin, V.; Tornow, Werner; Trimble, J. E.; Varner, R. L.; Vasilyev, Sergey; Vetter, Kai; Vorren, Kris R.; White, Brandon R.; Wilkerson, J. F.; Wiseman, C.; Xu, W.; Yakushev, E.; Young, A.; Yu, Chang-Hong; Yumatov, Vladimir

    2015-03-24

    The Majorana Demonstrator will search for neutrinoless-double-beta decay in 76Ge, while establishing the feasibility of a future tonne-scale germanium-based neutrinoless-double-beta decay experiment, and performing searches for new physics beyond the Standard Model. The experiment, currently under construction at the Sanford Underground Research Facility in Lead, SD, will consist of a pair of modular high-purity germanium detector arrays housed inside of a compact copper, lead, and polyethylene shield. Through a combination of strict materials qualifications and assay, low-background design, and powerful background rejection techniques, the Demonstrator aims to achieve a background rate in the neutrinoless-double-beta decay region of interest (ROI) of no more than 3cnts/(ROI-t-y). The current status of the Demonstrator is discussed, as are plans for its completion.

  15. The First Tests of a Large-Area Light Detector Equipped with Metallic Magnetic Calorimeters for Scintillating Bolometers for the LUMINEU Neutrinoless Double Beta Decay Search

    NASA Astrophysics Data System (ADS)

    Gray, D.; Enss, C.; Fleischmann, A.; Gastaldo, L.; Hassel, C.; Hengstler, D.; Kempf, S.; Loidl, M.; Navick, X. F.; Rodrigues, M.

    2016-08-01

    Future rare-event searches using scintillating crystals need very low background levels for high sensitivity; however, unresolved pile-up can limit this. We present the design and fabrication of large-area photon detectors based on metallic magnetic calorimeters (MMCs), optimized for fast rise times to resolve close pile-up. The first prototypes have been characterized using Fe-55 X-rays and ZnMoO4 crystal scintillation light. A fast intrinsic rise time of 25-30 \\upmu s has been measured and has been compared to the 250 \\upmu s scintillation light pulse rise time constant. The difference indicates that the scintillation process limits the light pulse rise time. The fast rise time allows for a reduction of background due to close pile-up events as well as the study of the inherent crystal scintillation process. MMC-based photon detectors are shown to be a promising tool for scintillating crystal based rare event searches.

  16. Status of LUMINEU program to search for neutrinoless double beta decay of {sup 100}Mo with cryogenic ZnMoO{sub 4} scintillating bolometers

    SciTech Connect

    Danevich, F. A. Boiko, R. S.; Chernyak, D. M.; Kobychev, V. V.; Bergé, L.; Chapellier, M.; Drillien, A.-A.; Dumoulin, L.; Humbert, V.; Marcillac, P. de; Marnieros, S.; Marrache-Kikuchi, C.; Olivieri, E.; Plantevin, O.; Tenconi, M.; Devoyon, L.; Koskas, F.; and others

    2015-10-28

    The LUMTNEU program aims at performing a pilot experiment on 0ν2β decay of {sup 100}Mo using radiopure ZnMoO{sub 4} crystals enriched in {sup 100}Mo operated as cryogenic scintillating bolometers. Large volume ZnMoO{sub 4} crystal scintillators (∼ 0.3 kg) were developed and tested showing high performance in terms of radiopurity, energy resolution and α/β particle discrimination capability. Zinc molybdate crystal scintillators enriched in {sup 100}Mo were grown for the first time by the low-thermal-gradient Czochralski technique with a high crystal yield and an acceptable level of enriched molybdenum irrecoverable losses. A background level of ∼ 0.5 counts/(yr keV ton) in the region of interest can be reached in a large detector array thanks to the excellent detectors radiopurity and particle discrimination capability, suppression of randomly coinciding events by pulse-shape analysis, and anticoincidence cut. These results pave the way to future sensitive searches based on the LUMTNEU technology, capable of approachingand exploring the inverted hierarchy region of the neutrino mass pattern.

  17. High-pressure Xenon Gas Electroluminescent TPC Concept for Simultaneous Searches for Neutrino-less Double Beta Decay & WIMP Dark Matter

    NASA Astrophysics Data System (ADS)

    Nygren, David

    2013-04-01

    Xenon is an especially attractive candidate for both direct WIMP and 0- decay searches. Although the current trend has exploited the liquid phase, gas phase xenon offers some remarkable performance advantages for energy resolution, topology visualization, and discrimination between electron and nuclear recoils. The NEXT-100 experiment, now beginning construction in the Canfranc Underground Laboratory, Spain, will operate at 12 bars with 100 kg of ^136Xe for the 0- decay search. I will describe recent results with small prototypes, indicating that NEXT-100 can provide about 0.5% FWHM energy resolution at the decay 2457.83 keV Q-value, as well as rejection of -rays by topology. However, sensitivity goals for WIMP dark matter and 0- decay searches indicate the need for ton-scale active masses; NEXT-100 provides the springboard to reach this scale with xenon gas. I describe a scenario for performing both searches in a single high-pressure ton-scale xenon gas detector, without significant compromise to either. In addition, -- even in a single, ton-scale, high-pressure xenon gas TPC, an intrinsic sensitivity to the nuclear recoil direction may exist -- plausibly offering an advance of more than two orders of magnitude relative to current low-pressure TPC concepts. I argue that, in an era of deepening fiscal austerity, such a dual-purpose detector may be possible, at acceptable cost, within the time frame of interest, and deserves our collective attention.

  18. Many-body correlations of QRPA in nuclear matrix elements of double-beta decay

    SciTech Connect

    Terasaki, J.

    2015-10-28

    We present two new ideas on the quasiparticle random-phase approximation (QRPA) approach for calculating nuclear matrix elements of double-beta decay. First, it is necessary to calculate overlaps of the QRPA states obtained on the basis of the ground states of different nuclei. We calculate this overlap using quasiboson vacua as the QRPA ground states. Second, we show that two-particle transfer paths are possible to use for the calculation under the closure approximation. A calculation is shown for {sup 150}Nd→{sup 150}Sm using these two new ideas, and their implication is discussed.

  19. Study of the double beta decays of 96Ru and 104Ru.

    PubMed

    Andreotti, Erica; Hult, Mikael; Marissens, Gerd; de Orduña, Raquel González; Vermaercke, Peter

    2012-09-01

    In this work we present new improved experimental limits for the partial half-lives of the double beta processes of (96)Ru and (104)Ru, obtained by means of a γ-ray spectrometry measurement. A disc of metallic Ru of natural isotopic abundance was sandwiched between two HPGe-detectors in the 225 m deep underground laboratory HADES. After 108 days of measurement, the lower bounds for the partial half-lives were up to 6.9×10(19) yr for (96)Ru and 1.9×10(20) yr for (104)Ru.

  20. Status of the MAJORANA DEMONSTRATOR

    NASA Astrophysics Data System (ADS)

    Vasilyev, S.; Abgrall, N.; Arnquist, I. J.; Avignone, F. T.; Balderrot-Barrera, C. X.; Barabash, A. S.; Bertrand, F. E.; Bradley, A. W.; Brudanin, V.; Busch, M.; Buuck, M.; Byram, D.; Caldwell, A. S.; Chan, Y.-D.; Christofferson, C. D.; Cuesta, C.; Detwiler, J. A.; Efremenko, Yu.; Ejiri, H.; Elliott, S. R.; Galindo-Uribarri, A.; Gilliss, T.; Giovanetti, G. K.; Goett, J.; Green, M. P.; Gruszko, J.; Guinn, I.; Guiseppe, V. E.; Henning, R.; Hoppe, E. W.; Howard, S.; Howe, M. A.; Jasinski, B. R.; Keeter, K. E.; Kidd, M. F.; Konovalov, S. I.; Kouzes, R. T.; LaFerriere, B. D.; Leon, J.; MacMullin, J.; Martin, R. D.; Meijer, S. J.; Mertens, S.; Orrell, J. L.; O'Shaughnessy, C.; Poon, A. W. P.; Radford, D. C.; Rager, J.; Rielage, K.; Robertson, R. G. H.; Romero-Romero, E.; Shanks, B.; Shirchenko, M.; Snyder, N.; Suriano, A. M.; Tedeschi, D.; Trimble, J. E.; Varner, R. L.; Vetter, K.; Vorren, K.; White, B. R.; Wilkerson, J. F.; Wiseman, C.; Xu, W.; Yakushev, E.; Yu, C.-H.; Yumatov, V.; Zhitnikov, I.

    2017-01-01

    The MAJORANA Collaboration is constructing the MAJORANA DEMONSTRATOR, an ultralow background, 40-kg modular high purity Ge (HPGe) detector array to search for neutrinoless double-beta decay (0νββ-decay) in 76Ge. The goal of the experiment is to demonstrate a background rate at or below 3 counts/(t-y) in the 4 keV region of interest (ROI) around the 2039 keV Q-value for 76Ge 0νββ-decay. In this paper, the status of the MAJORANA DEMONSTRATOR, including its design and measurements of properties of the HPGe crystals is presented.

  1. Production of very neutron-rich nuclei with a {sup 76}Ge beam

    SciTech Connect

    Tarasov, O. B.; Portillo, M.; Baumann, T.; Bazin, D.; Ginter, T. N.; Hausmann, M.; Pereira, J.; Stolz, A.; Amthor, A. M.; Gade, A.; Nettleton, A.; Sherrill, B. M.; Thoennessen, M.; Inabe, N.; Kubo, T.; Morrissey, D. J.

    2009-09-15

    Production cross sections for neutron-rich nuclei from the fragmentation of a {sup 76}Ge beam at 132 MeV/u were measured. The longitudinal momentum distributions of 34 neutron-rich isotopes of elements 13{<=}Z{<=}27 were scanned using a novel experimental approach of varying the target thickness. Production cross sections with beryllium and tungsten targets were determined for a large number of nuclei, including 15 isotopes first observed in this work. These are the most neutron-rich nuclides of the elements 17{<=}Z{<=}25 ({sup 50}Cl, {sup 53}Ar, {sup 55,56}K, {sup 57,58}Ca, {sup 59,60,61}Sc, {sup 62,63}Ti, {sup 65,66}V, {sup 68}Cr, and {sup 70}Mn). A one-body Q{sub g} systematics is used to describe the production cross sections based on thermal evaporation from excited prefragments. Some of the fragments near {sup 58}Ca show anomalously large production cross sections.

  2. Degeneracies of particle and nuclear physics uncertainties in neutrinoless β β decay

    NASA Astrophysics Data System (ADS)

    Lisi, E.; Rotunno, A. M.; Šimkovic, F.

    2015-11-01

    Theoretical estimates for the half-life of neutrinoless double beta decay (0 ν β β ) in candidate nuclei are affected by both particle and nuclear physics uncertainties, which may complicate the interpretation of decay signals or limits. We study such uncertainties and their degeneracies in the following context: three 0 ν β β nuclei of great interest for large-scale experiments (Ge 76 , Te 130 , Xe 136 ), two representative particle physics mechanisms (light and heavy Majorana neutrino exchange), and a large set of nuclear matrix elements (NME), computed within the quasiparticle random phase approximation (QRPA). It turns out that the main theoretical uncertainties, associated with the effective axial coupling gA and with the nucleon-nucleon potential, can be parametrized in terms of NME rescaling factors, up to small residuals. From this parametrization, the following QRPA features emerge: (1) the NME dependence on gA is milder than quadratic, (2) in each of the two mechanisms, the relevant lepton number violating parameter is largely degenerate with the NME rescaling factors, and (3) the light and heavy neutrino exchange mechanisms are basically degenerate in the above three nuclei. We comment on the challenging theoretical and experimental improvements required to reduce such particle and nuclear physics uncertainties and their degeneracies.

  3. Neutrino nuclear responses for double beta decays and astro neutrinos by charge exchange reactions

    NASA Astrophysics Data System (ADS)

    Ejiri, Hiroyasu

    2014-09-01

    Neutrino nuclear responses are crucial for neutrino studies in nuclei. Charge exchange reactions (CER) are shown to be used to study charged current neutrino nuclear responses associated with double beta decays(DBD)and astro neutrino interactions. CERs to be used are high energy-resolution (He3 ,t) reactions at RCNP, photonuclear reactions via IAR at NewSUBARU and muon capture reactions at MUSIC RCNP and MLF J-PARC. The Gamow Teller (GT) strengths studied by CERs reproduce the observed 2 neutrino DBD matrix elements. The GT and spin dipole (SD) matrix elements are found to be reduced much due to the nucleon spin isospin correlations and the non-nucleonic (delta isobar) nuclear medium effects. Impacts of the reductions on the DBD matrix elements and astro neutrino interactions are discussed.

  4. Double beta decays into excited states in 110Pd and 102Pd

    NASA Astrophysics Data System (ADS)

    Lehnert, B.; Andreotti, E.; Degering, D.; Hult, M.; Laubenstein, M.; Wester, T.; Zuber, K.

    2016-11-01

    A search for double beta decays of {}110{Pd} and {}102{Pd} into excited states of the daughter nuclides has been performed using three ultra-low background gamma-spectrometry measurements in the Felsenkeller laboratory, Germany, the HADES laboratory, Belgium and at the LNGS, Italy. The combined Bayesian analysis of the three measurements sets improved half-life limits for the 2νββ and 0νββ decay modes of the {2}1+, {0}1+ and {2}2+ transitions in {}110{Pd} to 2.9\\cdot {10}20 yr, 4.0\\cdot {10}20 yr and 3.0\\cdot {10}20 yr, respectively, and in {}102{Pd} to 7.6\\cdot {10}18 yr, 8.8\\cdot {10}18 yr and 1.4\\cdot {10}19 yr, respectively, with 90% credibility.

  5. Physics Division annual report, 1 January-31 December 1984

    SciTech Connect

    Not Available

    1985-10-01

    A brief overview of each of the several areas of research is given with a list of resulting publications. Areas of research include electron-positron annihilation, neutrino interactions, neutrinoless double beta decay of /sup 100/Mo, double beta decay of /sup 76/Ge, antiproton-proton interactions, right-handed gauge boson effects, muon decay asymmetry parameter measurements, supernovae detection, Nemesis search, and detector development. Areas of theoretical research include electroweak interactions, strong interactions, nonperturbative dynamics, supersymmetry, and cosmology and particle physics. 34 figs. (WRF)

  6. Effect of deformation on the valence shell occupancies of 74Ge, 76Ge, 76Se and 78Se

    NASA Astrophysics Data System (ADS)

    Elsharkawy, H. M.; Saleh Yousef, M.

    2017-03-01

    The set of BCS equations have been solved using both realistic and schematic separable forces to calculate the occupation probability amplitudes for protons and neutrons in the valence shells of 74Ge, 76Ge, 76Se and 78Se deformed nuclei. A comparison between the calculated occupation probabilities with the experimental measured values is introduced. A big difference is found between the occupation probabilities of protons with the experimental values, while for neutrons the agreement with the experimental values at high deformations is satisfactory.

  7. Search for double beta decay of 106Cd in the TGV-2 experiment

    NASA Astrophysics Data System (ADS)

    Rukhadze, N. I.; Brudanin, V. B.; Egorov, V. G.; Klimenko, A. A.; Kovalik, A.; Kouba, P.; Piquemal, F.; Rozov, S. V.; Rukhadze, E.; Salamatin, A. V.; Šimkovic, F.; Shitov, Yu A.; Štekl, I.; Timkin, V. V.; Yakushev, E. A.

    2016-05-01

    A new experimental run of searching for double beta decay of 106Cd was performed at the Modane underground laboratory (LSM, France, 4800 m w.e.) using the TGV-2 spectrometer, consisting of 32 planar type HPGe detectors with a total sensitive volume of ~400 cm3. 16 foils of 106Cd with an enrichment of 99.57% and a total mass of ~ 23.2 g were inserted between the entrance windows of face-to-face detectors. The limit on 2vEC/EC decay of 106Cd - T1/2 > 3.7 × 1020 y at 90% C.F was obtained from the preliminary calculation of experimental data accumulated for 8198 h of measurement. The limits on the resonance OvEC/EC decay of 106Cd were obtained from the measurement of ~23.2 g of 106Cd with the low-background HPGe spectrometer Obelix lasted 395 h -T1/2 (KF, 2741 keV) > 0.9 × 1020 y and T1/2 (KK, 2718 keV) > 1.4 × 1020 y at 90% C.L.

  8. Double {beta} experiments with the help of scintillation and HPGe detectors at Gran Sasso

    SciTech Connect

    Barabash, A.; Konovalov, S. I.; Umatov, V. I.; Belli, P.; D'Angelo, S.; Di Marco, A.; Bernabei, R.; Boiko, R. S.; Chernyak, D. M.; Danevich, F. A.; Kobychev, V. V.; Kropivyansky, B. N.; Kudovbenko, V. M.; Nagorny, S. S.; Podviyanuk, R. B.; Polischuk, O. G.; Tretyak, V. I.; Vyshnevskyi, I. M.; Yurchenko, S. S.; Brudanin, V. B.; and others

    2011-12-16

    A search for double beta decay of {sup 64,70}Zn, {sup 180,186}W was carried out by using low background ZnWO{sub 4} crystal scintillators, while a CeCl{sub 3} scintillation detector was applied to investigate 2{beta} processes in {sup 136,138,142}Ce. A search for 2{beta} decay of {sup 96,104}Ru, {sup 156,158}Dy, {sup 190,198}Pt and study of 2{nu}2{beta} decay of {sup 100}Mo to the first excited 0{sup +} level of {sup 100}Ru were realized by ultra-low background HPGe {gamma} spectrometry. Moreover, CdWO{sub 4} crystal scintillators from enriched {sup 106}Cd and {sup 116}Cd isotopes were developed to search for 2{beta} decay of {sup 106}Cd and {sup 116}Cd. Finally, experiments aimed to investigate {sup 96,104}Ru and {sup 116}Cd are in progress and a new phase of the experiment to search for 2{beta} processes in {sup 106}Cd is in preparation.

  9. Results from the Cuoricino (Zero-Neutrino Double Beta) Decay Experiment

    SciTech Connect

    Arnaboldi, C; Artusa, D R; Avignone, F T; Balata, M; Bandac, I; Barucci, M; Beeman, J W; Bellini, F; Brofferio, C; Bucci, C; Capelli, S; Carbone, L; Cebrian, S; Clemenza, M; Cremonesi, O; Creswick, R J; de Ward, A; Didomizio, S D; Dolinski, M J; Farach, H A; Fiorini, E; Frossati, G; Giachero, A; Giuliani, A; Gorla, P; Guardincerri, E; Gutierrez, T D; Haller, E E; Maruyama, R H; McDonald, R J; Nisi, S; Nones, C; Norman, E B; Nucciotti, A; Olivieri, E; Pallavicini, M; Palmieri, E; Pasca, E; Pavan, M; Pedretti, M; Pessina, G; Pirro, S; Previtali, E; Risegari, L; Rosenfeld, C; Sangiorgio, S; Sisti, M; Smith, A R; Torres, L; Ventura, G; Vignati, M

    2007-12-20

    Recent results from the CUORICINO {sup 130}Te zero-neutrino double-beta (0v{beta}{beta}) decay experiment are reported. CUORICINO is an array of 62 tellurium oxide (TeO{sub 2}) bolometers with an active mass of 40.7 kg. It is cooled to {approx}8 mK by a dilution refrigerator shielded from environmental radioactivity and energetic neutrons. It is running in the Laboratori Nazionali del Gran Sasso (LNGS) in Assergi, Italy. These data represent 11.83 kg y or 90.77 mole-years of {sup 130}Te. No evidence for 0v{beta}{beta}-decay was observed and a limit of T{sub 1/2}{sup 0v} ({sup 130}Te) {ge} 3.0 x 10{sup 24} y (90% C.L.) is set. This corresponds to upper limits on the effective mass, , between 0.19 and 0.68eV when analyzed with the many published nuclear structure calculations. In the context of these nuclear models, the values fall within the range corresponding to the claim of evidence of 0v{beta}{beta}-decay by H.V. Klapdor-Kleingrothaus and his co-workers. The experiment continues to acquire data.

  10. Electron-capture branch of {sup 100}Tc and tests of nuclear wave functions for double-{beta} decays.

    SciTech Connect

    Sjue, S. K. L.; Melconian, D.; Garcia, A.; Ahmad, I.; Algora, A.; Aysto, J.; Elomaa, V.-V.; Eronen, T.; Hakala, J.; Hoedl, S.; Kankainen, A.; Kessler, T.; Moore, I. D.; Naabe, F.; Penttila, H.; Rahaman, S.; Saastamoinen, A.; Swanson, H. E.; Weber, C.; Triambak, S.; Deryckx, K.; Physics; Univ. of Washington; Texas A&M Univ.; Univ. of Valencia; Hungarian Academy of Sciences; Univ. of Jyvaskyla; Univ. of Michigan

    2008-12-30

    We present a measurement of the electron-capture branch of {sup 100}Tc. Our value, B(EC) = (2.6 {+-} 0.4) x 10{sup -5}, implies that the {sup 100}Mo neutrino absorption cross section to the ground state of {sup 100}Tc is roughly 50% larger than previously thought. Disagreement between the experimental value and QRPA calculations relevant to double-{beta} decay matrix elements persists. We find agreement with previous measurements of the 539.5- and 590.8-keV {gamma}-ray intensities.

  11. MOON for spectroscopic studies of double beta decays and the present status of the MOON-1 prototype detector

    NASA Astrophysics Data System (ADS)

    Nakamura, H.; Ejiri, H.; Fushimi, K.; Ichihara, K.; Matsuoka, K.; Nomachi, M.; Hazama, R.; Umehara, S.; Yoshida, S.; Ogama, T.; Sakiuchi, T.; Hai, V. H.; Sugaya, Y.; Moon Collaboration

    2006-05-01

    The MOON (Molybdenum Observatory Of Neutrinos) project, as an extension of ELEGANT V, aims at spectroscopic studies of double beta decays from 100Mo with a sensitivity of the Majorana neutrino mass around 30 meV. Measurements with good energy and position resolutions enable one to select true signals and to reject background ones. A prototype MOON detector (MOON Phase-1A) with 142 g 100Mo was built and is running at the Oto underground laboratory. The present report describes briefly the outline of the MOON project and the present status of MOON-1.

  12. First results of a search for double beta decay of {sup 100}Mo with the NEMO 2 detector

    SciTech Connect

    NEMO Collaboration

    1993-06-15

    Double beta decay of {sup 100}Mo (172g) is studied with the NEMO 2 detector in the Frejus Underground Laboratory. The experiment has now accumulated 2485 hours of data taking. A clear signal of 380 events for 2{beta}2{nu} decay has been obtained corresponding to a half-life of T{sub {1/2}} = 1.0 {plus_minus} 0.08 (syst.) 10{sup 19} y. Limits are presented for 2{beta}(0{nu}, {chi}), 2{beta}0{nu} (ground state and excited states 2{sub 1}{sup +} and 0{sub 1}{sup +}). The experiment will run til October 1993.

  13. Status of the Majorana Demonstrator

    DOE PAGES

    Cuesta, C.; Abgrall, N.; Arnquist, I. J.; ...

    2015-08-06

    The Majorana Collaboration is constructing the Majorana Demonstrator, an ultra-low background, 40-kg modular high purity Ge detector array to search for neutrinoless double-beta decay in 76Ge. In view of the next generation of tonne-scale Ge-based neutrinoless double-beta decay searches that will probe the neutrino mass scale in the inverted-hierarchy region, a major goal of the Demonstrator is to demonstrate a path forward to achieving a background rate at or below 1 count/tonne/year in the 4 keV region of interest around the Q-value at 2039 keV. Lastly, the current status of the Demonstrator is discussed, as are plans for its completion.

  14. THE MAJORANA DEMONSTRATOR: OVERVIEW AND STATUS UPDATE

    SciTech Connect

    Keeter, K.; Abgrall, N.; Aguayo, Estanislao; Avignone, F. T.; Barabash, Alexander; Bertrand, F.; Boswell, M.; Brudanin, V.; Busch, Matthew; Caldwell, A. S.; Chan, Yuen-Dat; Christofferson, Cabot-Ann; Combs, Dustin C.; Cuesta, C.; Detwiler, Jason A.; Doe, Peter J.; Efremenko, Yuri; Egorov, Viatcheslav; Ejiri, H.; Elliott, S.; Esterline, James H.; Fast, James E.; Finnerty, P.; Fraenkle, Florian; Galindo-Uribarri, A.; Giovanetti, G. K.; Goett, J.; Green, Matthew P.; Gruszko, J.; Guiseppe, Vincente; Gusev, K.; Hallin, A. L.; Hazama, R.; Hegai, A.; Henning, Reyco; Hoppe, Eric W.; Howard, Stanley; Howe, M. A.; Kidd, M. F.; Kochetov, Oleg; Konovalov, S.; Kouzes, Richard T.; LaFerriere, Brian D.; Leon, Jonathan D.; Leviner, L.; Loach, J. C.; MacMullin, S.; Martin, R. D.; Mertens, S.; Mizouni, Leila; Nomachi, Masaharu; O'Shaughnessy, Mark D.; Orrell, John L.; Overman, Nicole R.; Phillips, D.; Poon, Alan; Pushkin, K.; Radford, D. C.; Rielage, Keith; Robertson, R. G. H.; Ronquest, M. C.; Schubert, Alexis G.; Shanks, B.; Shima, T.; Shirchenko, M.; Snavely, Kyle J.; Snyder, N.; Soin, Aleksandr; Strain, J.; Suriano, Anne-Marie; Swift, Gary; Thompson, J.; Timkin, V.; Tornow, Werner; Varner, R. L.; Vasilyev, Sergey; Vetter, Kai; Vorren, Kris R.; White, Brandon R.; Wilkerson, J. F.; Wiseman, C.; Xu, W.; Yakushev, E.; Young, A.; Yu, Chang-Hong; Yumatov, Vladimir

    2013-04-12

    The MAJORANA DEMONSTRATOR is being constructed at the Sanford Underground Research Facility (SURF) in Lead, SD by the MAJORANA Collaboration to demonstrate the feasibility of a tonne-scale neutrinoless double beta decay experiment based on 76Ge. The observation of neutrinoless double beta decay would indicate that neutrinos can serve as their own antiparticles, thus proving neutrinos to be Majorana particles, and would give information on neutrino masses. Attaining sensitivities for neutrino masses in the inverted hierarchy region requires large tonne-scale detectors with extremely low backgrounds. The DEMONSTRATOR project will show that sufficiently low backgrounds are achievable. A brief description of the detector and a status update on the construction will be given, including the work done at BHSU on acid-etching of Pb shielding bricks.

  15. On the neutrinoless double β{sup +}/EC decays

    SciTech Connect

    Suhonen, Jouni

    2013-12-30

    The neutrinoless double positron-emission/electron-capture (0νβ{sup +}/EC) decays are studied for the magnitudes of the involved nuclear matrix elements (NMEs). Decays to the ground state, 0{sub gs}{sup +}, and excited 0{sup +} states are discussed. The participant many-body wave functions are evaluated in the framework of the quasiparticle random-phase approximation (QRPA). Effective, G-matrix-derived nuclear forces are used in realistic single-particle model spaces. The channels β{sup +}β{sup +}, β{sup +}EC, and the resonant neutrinoless double electron capture (R0νECEC) are discussed.

  16. Limits on neutrino masses from neutrinoless double-β decay.

    PubMed

    Barea, J; Kotila, J; Iachello, F

    2012-07-27

    Neutrinoless double-β decay is of fundamental importance for the determining neutrino mass. By combining a calculation of nuclear matrix elements within the framework of the microscopic interacting boson model with an improved calculation of phase space factors, we set limits on the average light neutrino mass and on the average inverse heavy neutrino mass (flavor-violating parameter).

  17. Gaseous time projection chambers for rare event detection: results from the T-REX project. I. Double beta decay

    SciTech Connect

    Irastorza, I.G.; Aznar, F.; Castel, J. E-mail: faznar@unizar.es [Grupo de Física Nuclear y Astropartículas, Departamento de Física Teórica, Universidad de Zaragoza, C and others

    2016-01-01

    As part of the T-REX project, a number of R and D and prototyping activities have been carried out during the last years to explore the applicability of gaseous Time Projection Chambers (TPCs) with Micromesh Gas Structures (Micromegas) in rare event searches like double beta decay, axion research and low-mass WIMP searches. In both this and its companion paper, we compile the main results of the project and give an outlook of application prospects for this detection technique. While in the companion paper we focus on axions and WIMPs, in this paper we focus on the results regarding the measurement of the double beta decay (DBD) of {sup 136}Xe in a high pressure Xe (HPXe) TPC. Micromegas of the microbulk type have been extensively studied in high pressure Xe and Xe mixtures. Particularly relevant are the results obtained in Xe + trimethylamine (TMA) mixtures, showing very promising results in terms of gain, stability of operation, and energy resolution at high pressures up to 10 bar. The addition of TMA at levels of ∼ 1% reduces electron diffusion by up to a factor of 10 with respect to pure Xe, improving the quality of the topological pattern, with a positive impact on the discrimination capability. Operation with a medium size prototype of 30 cm diameter and 38 cm of drift (holding about 1 kg of Xe at 10 bar in the fiducial volume, enough to contain high energy electron tracks in the detector volume) has allowed to test the detection concept in realistic experimental conditions. Microbulk Micromegas are able to image the DBD ionization signature with high quality while, at the same time, measuring its energy deposition with a resolution of at least a ∼ 3% FWHM @ Q{sub ββ}. This value was experimentally demonstrated for high-energy extended tracks at 10 bar, and is probably improvable down to the ∼ 1% FWHM levels as extrapolated from low energy events. In addition, first results on the topological signature information (one straggling track ending in two

  18. Analysis techniques for the evaluation of the neutrinoless double-β decay lifetime in 130Te with the CUORE-0 detector

    NASA Astrophysics Data System (ADS)

    Alduino, C.; Alfonso, K.; Artusa, D. R.; Avignone, F. T.; Azzolini, O.; Banks, T. I.; Bari, G.; Beeman, J. W.; Bellini, F.; Bersani, A.; Biassoni, M.; Brofferio, C.; Bucci, C.; Caminata, A.; Canonica, L.; Cao, X. G.; Capelli, S.; Cappelli, L.; Carbone, L.; Cardani, L.; Carniti, P.; Casali, N.; Cassina, L.; Chiesa, D.; Chott, N.; Clemenza, M.; Copello, S.; Cosmelli, C.; Cremonesi, O.; Creswick, R. J.; Cushman, J. S.; Dafinei, I.; Dally, A.; Davis, C. J.; Dell'Oro, S.; Deninno, M. M.; di Domizio, S.; di Vacri, M. L.; Drobizhev, A.; Fang, D. Q.; Faverzani, M.; Fernandes, G.; Ferri, E.; Ferroni, F.; Fiorini, E.; Freedman, S. J.; Fujikawa, B. K.; Giachero, A.; Gironi, L.; Giuliani, A.; Gladstone, L.; Gorla, P.; Gotti, C.; Gutierrez, T. D.; Haller, E. E.; Han, K.; Hansen, E.; Heeger, K. M.; Hennings-Yeomans, R.; Hickerson, K. P.; Huang, H. Z.; Kadel, R.; Keppel, G.; Kolomensky, Yu. G.; Lim, K. E.; Liu, X.; Ma, Y. G.; Maino, M.; Marini, L.; Martinez, M.; Maruyama, R. H.; Mei, Y.; Moggi, N.; Morganti, S.; Mosteiro, P. J.; Nones, C.; Norman, E. B.; Nucciotti, A.; O'Donnell, T.; Orio, F.; Ouellet, J. L.; Pagliarone, C. E.; Pallavicini, M.; Palmieri, V.; Pattavina, L.; Pavan, M.; Pessina, G.; Pettinacci, V.; Piperno, G.; Pirro, S.; Pozzi, S.; Previtali, E.; Rosenfeld, C.; Rusconi, C.; Sala, E.; Sangiorgio, S.; Santone, D.; Scielzo, N. D.; Singh, V.; Sisti, M.; Smith, A. R.; Taffarello, L.; Tenconi, M.; Terranova, F.; Tomei, C.; Trentalange, S.; Ventura, G.; Vignati, M.; Wagaarachchi, S. L.; Wang, B. S.; Wang, H. W.; Wilson, J.; Winslow, L. A.; Wise, T.; Woodcraft, A.; Zanotti, L.; Zhang, G. Q.; Zhu, B. X.; Zimmermann, S.; Zucchelli, S.; Cuore Collaboration

    2016-04-01

    We describe in detail the methods used to obtain the lower bound on the lifetime of neutrinoless double-beta (0 ν β β ) decay in 130Te and the associated limit on the effective Majorana mass of the neutrino using the CUORE-0 detector. CUORE-0 is a bolometric detector array located at the Laboratori Nazionali del Gran Sasso that was designed to validate the background reduction techniques developed for CUORE, a next-generation experiment scheduled to come online in 2016. CUORE-0 is also a competitive 0 ν β β decay search in its own right and functions as a platform to further develop the analysis tools and procedures to be used in CUORE. These include data collection, event selection and processing, as well as an evaluation of signal efficiency. In particular, we describe the amplitude evaluation, thermal gain stabilization, energy calibration methods, and the analysis event selection used to create our final 0 ν β β search spectrum. We define our high level analysis procedures, with emphasis on the new insights gained and challenges encountered. We outline in detail our fitting methods near the hypothesized 0 ν β β decay peak and catalog the main sources of systematic uncertainty. Finally, we derive the 0 ν β β decay half-life limits previously reported for CUORE-0, T1/2 0 ν>2.7 ×1024yr , and in combination with the Cuoricino limit, T1/2 0 ν>4.0 ×1024yr .

  19. Studies on the double-{beta} decay nucleus {sup 64}Zn using the (d,{sup 2}He) reaction

    SciTech Connect

    Grewe, E.-W.; Baeumer, C.; Dohmann, H.; Frekers, D.; Hollstein, S.; Rakers, S.; Thies, J. H.; Harakeh, M. N.; Berg, A. M. van den; Woertche, H. J.; Johansson, H.; Martinez-Pinedo, G.; Petermann, I.; Sieja, K.; Simon, H.; Langanke, K.; Nowacki, F.; Popescu, L.; Savran, D.; Zilges, A.

    2008-06-15

    The (d,{sup 2}He) charge-exchange reaction on the double-{beta} decay ({beta}{beta}) nucleus {sup 64}Zn has been studied at an incident energy of 183 MeV. The two protons in the {sup 1}S{sub 0} state (indicated as {sup 2}He) were both momentum analyzed and detected simultaneously by the BBS magnetic spectrometer and its position-sensitive detector. {sup 2}He spectra with a resolution of about 115 keV (FWHM) have been obtained allowing identification of many levels in the residual nucleus {sup 64}Cu with high precision. {sup 64}Zn is one of the rare cases undergoing a {beta}{beta} decay in {beta}{sup +} direction. In the experiment presented here, Gamow-Teller (GT{sup +}) transition strengths have been extracted. Together with the GT{sup -} transition strengths from {sup 64}Ni({sup 3}He,t) data to the same intermediate nucleus {sup 64}Cu, the nuclear matrix elements of the {beta}{beta} decay of {sup 64}Zn have been evaluated. Finally, the GT{sup {+-}} distributions are compared with shell-model calculations and a critical assessment is given of the various residual interactions presently employed for the pf shell.

  20. Neutron-Induced Partial Cross-Section Measurements on ^76Ge Motivated by The Majorana Project 0νββ Decay Search

    NASA Astrophysics Data System (ADS)

    Hilderbrand, S.; Kwan, E.; Angell, C.; Fallin, B.; Howell, C. R.; Hutcheson, A.; Karwowski, H. J.; Kelley, J. H.; Tonchev, A. P.; Tornow, W.; Masters, D. B.; Pedroni, R. S.; Weisel, G. J.

    2007-10-01

    The goal of the Majorana Collaboration is to study 0νββ in order to verify that the neutrino is its own anti-particle; and if so, what is the mass ofthe electron neutrino. Observation of a sharp peak at the ββ endpoint energy will confirm 0νββ as a decay mode, and determination of the partial width will determine the matrix element which depends directly on the electron neutrino mass. In order to observe and verify the existence of 0νββ, it is important to reduce intrinsic, extrinsic,& cosmogenic backgrounds. The Majorana Project will operate with HPGe detectors deep underground to achieve a low-background environment. Recent advances in signal processing and detector design have also enabled scientists to further understand background sources. γ-ray spectra from the interaction of pulsed mono-energetic neutrons with ^76Ge were measured at TUNL using segmented HPGe clover detectors. The neutron-induced partial cross-sections for γ transitions in ^76Ge were measured at En = 8 and 12MeV.

  1. Search for double beta processes in {sup 106}Cd with enriched {sup 106}CdWO{sub 4} crystal scintillator in coincidence with four crystals HPGe detector

    SciTech Connect

    Danevich, F. A. Chernyak, D. M.; Mokina, V. M.; Belli, P.; Bernabei, R.; D’Angelo, S.; Brudanin, V. B.; Cappella, F.; Caracciolo, V.; Cerulli, R.; Laubenstein, M.; Incicchitti, A.; Poda, D. V.; Polischuk, O. G.; Tretyak, V. I.; Tupitsyna, I. A.

    2015-10-28

    A radiopure cadmium tungstate crystal scintillator, enriched in {sup 106}Cd ({sup 106}CdWO{sub 4}), was used to search for double beta decay processes in {sup 106}Cd in coincidence with an ultra-low background set-up containing four high purity germanium (HPGe) detectors in a single cryostat. The experiment has been completed after 13085 h of data taking. New improved limits on most of the double beta processes in {sup 106}Cd have been set on the level of 10{sup 20}−10{sup 21} yr. Tn particular, the half-life limit on the two neutrino electron capture with positron emission, T{sub 1/2} ≥ 1.8 × 10{sup 21} yr, reached the region of theoretical predictions.

  2. Neutrinoless ββ-decay in gauge theories

    NASA Astrophysics Data System (ADS)

    Vergados, J. D.

    1983-06-01

    The lepton violating neutrinoless ββ-decay is investigated in the context of fashionable gauge theories. Various mechanisms are examined e.g. light or heavy neutrinos, with or without righ-handed currents, intermediate doubly charged Higgs Particles, Majoran emisison etc. Numberical results have been obtained for the transitions 48Ca→8Ti(β-β-) and 58Ni→58Fe (β+B+, electron capture, double electron capture) employing realistic nuclear models.

  3. Front-End Electronics Characterization, Production, and QA for the Majorana Demonstrator

    NASA Astrophysics Data System (ADS)

    Elia, Sophia; Majorana Collaboration

    2014-09-01

    The Majorana Demonstrator will search for the neutrinoless double beta decay ββ (0 ν) of the isotope 76Ge. In anticipation of the future tonne-scale experiments, its goal is to demonstrate a path forward to a background rate of one cnt/(ROI-t-y) in a 4 keV region around the Q-value of the 76Ge ββ (0 ν) . Such a background requirement significantly constrains the design of the front end electronics. Low background and low noise qualifications are a necessity. This poster first presents the characterization and noise performance in single and multi detector systems of the front end electronics developed for Majorana. The poster next reviews the full production process and finally describes the Quality Assurance tests developed for the electronics before installation in the experiment. The Majorana Demonstrator will search for the neutrinoless double beta decay ββ (0 ν) of the isotope 76Ge. In anticipation of the future tonne-scale experiments, its goal is to demonstrate a path forward to a background rate of one cnt/(ROI-t-y) in a 4 keV region around the Q-value of the 76Ge ββ (0 ν) . Such a background requirement significantly constrains the design of the front end electronics. Low background and low noise qualifications are a necessity. This poster first presents the characterization and noise performance in single and multi detector systems of the front end electronics developed for Majorana. The poster next reviews the full production process and finally describes the Quality Assurance tests developed for the electronics before installation in the experiment. We acknowledge support from the Office of Nuclear Physics in the DOE Office of Science, the Particle and Nuclear Astrophysics Program of the National Science Foundation and the Russian Foundation for Basic Research.

  4. Virtual Compton Scattering and the Generalized Polarizabilities of the Proton at Q^2=0.92 and 1.76 GeV^2

    SciTech Connect

    Helene Fonvieille, Geraud Laveissiere, Natalie Degrande, Stephanie Jaminion, Christophe Jutier, Luminita Todor, L. Van Hoorebeke, Bryon Anderson, Konrad Aniol, Kathleen Arundell, Gerard Audit, Leonard Auerbach, F. Baker, Maud Baylac, J. Berthot, Pierre Bertin, William Bertozzi, Louis Bimbot, Werner Boeglin, Edward Brash, Vincent Breton, Herbert Breuer, Etienne Burtin, John Calarco, Lawrence Cardman, Christian Cavata, Jian-Ping Chen, Eugene Chudakov, Evaristo Cisbani, Daniel Dale, Cornelis De Jager, Raffaele De Leo, Alexandre Deur, Nicole D'Hose, Gail Dodge, John Domingo, Latifa Elouadrhiri, Martin Epstein, Lars Ewell, John Finn, Kevin Fissum, Guy Fournier, Bernhard Frois, Salvatore Frullani, Christophe Furget, Haiyan Gao, Juncai Gao, Franco Garibaldi, Ashot Gasparian, Shalev Gilad, Ronald Gilman, Oleksandr Glamazdin, Charles Glashausser, Javier Gomez, Viktor Gorbenko, Pierre Guichon, Jens-Ole Hansen, Richard Holmes, Maurik Holtrop, Calvin Howell, Garth Huber, Charles Hyde, Sebastien Incerti, Mauro Iodice, Johann Jardillier, Mark Jones, Seigo Kato, James Kelly, Armen Ketikyan, Mohammad Khayat, Kouichi Kino, Serge Kox, Laird Kramer, Krishna Kumar, Gerfried Kumbartzki, Michael Kuss, Antonio Leone, John LeRose, Richard Lindgren, Nilanga Liyanage, George Lolos, Kazushige Maeda, Sergey Malov, D. Manley, Claude Marchand, Dominique Marchand, Demetrius Margaziotis, Pete Markowitz, Jacques Marroncle, Jacques Martino, Kathy McCormick, James McIntyre, Surik Mehrabyan, Fernand Merchez, Zein-Eddine Meziani, Robert Michaels, Jean Mougey, Sirish Nanda, Amra Offermann, Zisis Papandreou, Charles Perdrisat, R. Perrino, Gerassimos Petratos, Stephane Platchkov, Roman Pomatsalyuk, David Prout, Vina Punjabi, Thierry Pussieux, Gilles Quemener, Ronald Ransome, Oliver Ravel, Jean-Sebastien Real, Yves Roblin, David Rowntree, Gary Rutledge, Paul Rutt, Arunava Saha, Teijiro Saito, Adam Sarty, Tim Smith, Paul Souder, Riad Suleiman, Jeffrey Templon, Tatsuo Terasawa, Raphael Tieulent, Egle Tomasi, Hiroaki Tsubota, Hiroaki Ueno, Paul Ulmer, Guido Urciuoli, Marc Vanderhaeghen, Rob van der Meer, R.Van De Vyver, Pascal Vernin, Branislav Vlahovic, Hakob Voskanyan, Eric Voutier, John Watson, Lawrence Weinstein, Krishni Wijesooriya, Richard Wilson, Bogdan Wojtsekhowski, Dan Zainea, Zilu Zhou, Rachele Di Salvo

    2012-07-01

    Virtual Compton Scattering (VCS) on the proton has been studied at Jefferson Lab using the exclusive photon electroproduction reaction (e p --> e p gamma). This paper gives a detailed account of the analysis which has led to the determination of the structure functions P{sub LL}-P{sub TT}/epsilon and P{sub LT}, and the electric and magnetic generalized polarizabilities (GPs) alpha{sub E}(Q{sup 2}) and beta{sub M}(Q{sup 2}) at values of the four-momentum transfer squared Q{sup 2} = 0.92 and 1.76 GeV{sup 2}. These data, together with the results of VCS experiments at lower momenta, help building a coherent picture of the electric and magnetic GPs of the proton over the full measured Q{sup 2}-range, and point to their non-trivial behavior.

  5. Measurement of the Generalized Polarizabilities of the Proton in Virtual Compton Scattering at Q2= 0.92 and 1.76 GeV2

    SciTech Connect

    Geraud Laveissiere; Natalie Degrande; Stephanie Jaminion; Christophe Jutier; Luminita Todor; Rachele Di Salvo; L. Van Hoorebeke; Et. Al.

    2004-09-01

    We report a Virtual Compton Scattering study of the proton at low CM energies. We have determined the structure functions P{sub LL} - P{sub TT}/{epsilon} and P{sub LT}, and the electric and magnetic Generalized Polarizabilities (GPs) {alpha}{sub E}(Q{sup 2}) and {beta}{sub M}(Q{sup 2}) at momentum transfer Q{sup 2} = 0.92 and 1.76 GeV{sup 2}. The electric GP shows a strong fall-off with Q{sup 2}, and its global behavior does not follow a simple dipole form. The magnetic GP shows a rise and then a fall-off; this can be interpreted as the dominance of a long-distance diamagnetic pion cloud at low Q{sup 2}, compensated at higher Q{sup 2} by a paramagnetic contribution from {pi}N intermediate states.

  6. Virtual Compton scattering and the generalized polarizabilities of the proton at Q2=0.92 and 1.76 GeV2

    NASA Astrophysics Data System (ADS)

    Fonvieille, H.; Laveissière, G.; Degrande, N.; Jaminion, S.; Jutier, C.; Todor, L.; Di Salvo, R.; Van Hoorebeke, L.; Alexa, L. C.; Anderson, B. D.; Aniol, K. A.; Arundell, K.; Audit, G.; Auerbach, L.; Baker, F. T.; Baylac, M.; Berthot, J.; Bertin, P. Y.; Bertozzi, W.; Bimbot, L.; Boeglin, W. U.; Brash, E. J.; Breton, V.; Breuer, H.; Burtin, E.; Calarco, J. R.; Cardman, L. S.; Cavata, C.; Chang, C.-C.; Chen, J.-P.; Chudakov, E.; Cisbani, E.; Dale, D. S.; de Jager, C. W.; De Leo, R.; Deur, A.; d'Hose, N.; Dodge, G. E.; Domingo, J. J.; Elouadrhiri, L.; Epstein, M. B.; Ewell, L. A.; Finn, J. M.; Fissum, K. G.; Fournier, G.; Frois, B.; Frullani, S.; Furget, C.; Gao, H.; Gao, J.; Garibaldi, F.; Gasparian, A.; Gilad, S.; Gilman, R.; Glamazdin, A.; Glashausser, C.; Gomez, J.; Gorbenko, V.; Grenier, P.; Guichon, P. A. M.; Hansen, J. O.; Holmes, R.; Holtrop, M.; Howell, C.; Huber, G. M.; Hyde, C. E.; Incerti, S.; Iodice, M.; Jardillier, J.; Jones, M. K.; Kahl, W.; Kato, S.; Katramatou, A. T.; Kelly, J. J.; Kerhoas, S.; Ketikyan, A.; Khayat, M.; Kino, K.; Kox, S.; Kramer, L. H.; Kumar, K. S.; Kumbartzki, G.; Kuss, M.; Leone, A.; LeRose, J. J.; Liang, M.; Lindgren, R. A.; Liyanage, N.; Lolos, G. J.; Lourie, R. W.; Madey, R.; Maeda, K.; Malov, S.; Manley, D. M.; Marchand, C.; Marchand, D.; Margaziotis, D. J.; Markowitz, P.; Marroncle, J.; Martino, J.; McCormick, K.; McIntyre, J.; Mehrabyan, S.; Merchez, F.; Meziani, Z. E.; Michaels, R.; Miller, G. W.; Mougey, J. Y.; Nanda, S. K.; Neyret, D.; Offermann, E. A. J. M.; Papandreou, Z.; Pasquini, B.; Perdrisat, C. F.; Perrino, R.; Petratos, G. G.; Platchkov, S.; Pomatsalyuk, R.; Prout, D. L.; Punjabi, V. A.; Pussieux, T.; Quémenér, G.; Ransome, R. D.; Ravel, O.; Real, J. S.; Renard, F.; Roblin, Y.; Rowntree, D.; Rutledge, G.; Rutt, P. M.; Saha, A.; Saito, T.; Sarty, A. J.; Serdarevic, A.; Smith, T.; Smirnov, G.; Soldi, K.; Sorokin, P.; Souder, P. A.; Suleiman, R.; Templon, J. A.; Terasawa, T.; Tieulent, R.; Tomasi-Gustaffson, E.; Tsubota, H.; Ueno, H.; Ulmer, P. E.; Urciuoli, G. M.; Vanderhaeghen, M.; Van der Meer, R. L. J.; Van De Vyver, R.; Vernin, P.; Vlahovic, B.; Voskanyan, H.; Voutier, E.; Watson, J. W.; Weinstein, L. B.; Wijesooriya, K.; Wilson, R.; Wojtsekhowski, B. B.; Zainea, D. G.; Zhang, W.-M.; Zhao, J.; Zhou, Z.-L.

    2012-07-01

    Virtual Compton scattering (VCS) on the proton has been studied at the Jefferson Laboratory using the exclusive photon electroproduction reaction ep→epγ. This paper gives a detailed account of the analysis which has led to the determination of the structure functions PLL-PTT/ɛ and PLT and the electric and magnetic generalized polarizabilities (GPs) αE(Q2) and βM(Q2) at values of the four-momentum transfer squared Q2=0.92 and 1.76 GeV2. These data, together with the results of VCS experiments at lower momenta, help building a coherent picture of the electric and magnetic GPs of the proton over the full measured Q2 range and point to their nontrivial behavior.

  7. Measurement of the generalized polarizabilities of the proton in virtual Compton scattering at Q2=0.92 and 1.76 GeV2.

    PubMed

    Laveissière, G; Todor, L; Degrande, N; Jaminion, S; Jutier, C; Di Salvo, R; Van Hoorebeke, L; Alexa, L C; Anderson, B D; Aniol, K A; Arundell, K; Audit, G; Auerbach, L; Baker, F T; Baylac, M; Berthot, J; Bertin, P Y; Bertozzi, W; Bimbot, L; Boeglin, W U; Brash, E J; Breton, V; Breuer, H; Burtin, E; Calarco, J R; Cardman, L S; Cavata, C; Chang, C-C; Chen, J-P; Chudakov, E; Cisbani, E; Dale, D S; de Jager, C W; De Leo, R; Deur, A; d'Hose, N; Dodge, G E; Domingo, J J; Elouadrhiri, L; Epstein, M B; Ewell, L A; Finn, J M; Fissum, K G; Fonvieille, H; Fournier, G; Frois, B; Frullani, S; Furget, C; Gao, H; Gao, J; Garibaldi, F; Gasparian, A; Gilad, S; Gilman, R; Glamazdin, A; Glashausser, C; Gomez, J; Gorbenko, V; Grenier, P; Guichon, P A M; Hansen, J O; Holmes, R; Holtrop, M; Howell, C; Huber, G M; Hyde-Wright, C E; Incerti, S; Iodice, M; Jardillier, J; Jones, M K; Kahl, W; Kato, S; Katramatou, A T; Kelly, J J; Kerhoas, S; Ketikyan, A; Khayat, M; Kino, K; Kox, S; Kramer, L H; Kumar, K S; Kumbartzki, G; Kuss, M; Leone, A; LeRose, J J; Liang, M; Lindgren, R A; Liyanage, N; Lolos, G J; Lourie, R W; Madey, R; Maeda, K; Malov, S; Manley, D M; Marchand, C; Marchand, D; Margaziotis, D J; Markowitz, P; Marroncle, J; Martino, J; McCormick, K; McIntyre, J; Mehrabyan, S; Merchez, F; Meziani, Z E; Michaels, R; Miller, G W; Mougey, J Y; Nanda, S K; Neyret, D; Offermann, E A J M; Papandreou, Z; Pasquini, B; Perdrisat, C F; Perrino, R; Petratos, G G; Platchkov, S; Pomatsalyuk, R; Prout, D L; Punjabi, V A; Pussieux, T; Quémenér, G; Ransome, R D; Ravel, O; Real, J S; Renard, F; Roblin, Y; Rowntree, D; Rutledge, G; Rutt, P M; Saha, A; Saito, T; Sarty, A J; Serdarevic, A; Smith, T; Smirnov, G; Soldi, K; Sorokin, P; Souder, P A; Suleiman, R; Templon, J A; Terasawa, T; Tieulent, R; Tomasi-Gustaffson, E; Tsubota, H; Ueno, H; Ulmer, P E; Urciuoli, G M; Vanderhaeghen, M; Van De Vyver, R; Van der Meer, R L J; Vernin, P; Vlahovic, B; Voskanyan, H; Voutier, E; Watson, J W; Weinstein, L B; Wijesooriya, K; Wilson, R; Wojtsekhowski, B B; Zainea, D G; Zhang, W-M; Zhao, J; Zhou, Z-L

    2004-09-17

    We report a virtual Compton scattering study of the proton at low c.m. energies. We have determined the structure functions P(LL)-P(TT)/epsilon and P(LT), and the electric and magnetic generalized polarizabilities (GPs) alpha(E)(Q2) and beta(M)(Q2) at momentum transfer Q(2)=0.92 and 1.76 GeV2. The electric GP shows a strong falloff with Q2, and its global behavior does not follow a simple dipole form. The magnetic GP shows a rise and then a falloff; this can be interpreted as the dominance of a long-distance diamagnetic pion cloud at low Q2, compensated at higher Q2 by a paramagnetic contribution from piN intermediate states.

  8. A Search for Neutrinoless Tau Decays to Three Leptons

    SciTech Connect

    Kolb, Jeffrey A.

    2008-06-01

    Using approximately 350 million τ+τ- pair events recorded with the BaBar detector at the Stanford Linear Accelerator Center between 1999 and 2006, a search has been made for neutrinoless, lepton-flavor violating tau decays to three lighter leptons. All six decay modes consistent with conservation of electric charge and energy have been considered. With signal selection efficiencies of 5-12%, we obtain 90% confidence level upper limits on the branching fraction β}(τ → ℓℓℓ) in the range (4-8) x 10-8.

  9. Development of radiopure cadmium tungstate crystal scintillators from enriched {sup 106}Cd and {sup 116}Cd to search for double beta decay

    SciTech Connect

    Danevich, F. A.; Boiko, R. S.; Chernyak, D. M.; Kobychev, V. V.; Kropivyansky, B. N.; Mokina, V. M.; Nikolaiko, A. S.; Poda, D. V.; Podviyanuk, R. B.; Tretyak, V. I.; Barabash, A. S.; Konovalov, S. I.; Umatov, V. I.; Belli, P.; Bernabei, R.; D'Angelo, S.; Brudanin, V. B.; Cappella, F.; Incicchitti, A.; Caracciolo, V.; and others

    2013-08-08

    Cadmium tungstate crystal scintillators enriched in {sup 106}Cd up to 66% ({sup 106}CdWO{sub 4}) and in {sup 116}Cd up to 82% ({sup 116}CdWO{sub 4}) have been developed. The low radioactive contamination of the crystals measured on the level of ≤ 1.5 mBq/kg ({sup 40}K), ≤ 0.005 - 0.012 mBq/kg ({sup 226}Ra), 0.04 - 0.07 mBq/kg ({sup 228}Th) allows to carry out high sensitivity experiments to search for double beta processes in {sup 106}Cd and {sup 116}Cd.

  10. Neutrinoless double β decay and low scale leptogenesis

    NASA Astrophysics Data System (ADS)

    Drewes, Marco; Eijima, Shintaro

    2016-12-01

    The extension of the Standard Model by right handed neutrinos with masses in the GeV range can simultaneously explain the observed neutrino masses via the seesaw mechanism and the baryon asymmetry of the universe via leptogenesis. It has previously been claimed that the requirement for successful baryogenesis implies that the rate of neutrinoless double β decay in this scenario is always smaller than the standard prediction from light neutrino exchange alone. In contrast, we find that the rate for this process can also be enhanced due to a dominant contribution from heavy neutrino exchange. In a small part of the parameter space it even exceeds the current experimental limit, while the properties of the heavy neutrinos are consistent with all other experimental constraints and the observed baryon asymmetry is reproduced. This implies that neutrinoless double β decay experiments have already started to rule out part of the leptogenesis parameter space that is not constrained by any other experiment, and the lepton number violation that is responsible for the origin of baryonic matter in the universe may be observed in the near future.

  11. Status of the Majorana Demonstrator

    SciTech Connect

    Cuesta, C.; Buuck, M.; Detwiler, J. A.; Gruszko, J.; Guinn, I. S.; Leon, J.; Robertson, R. G. H.; Abgrall, N.; Bradley, A. W.; Chan, Y.-D.; Mertens, S.; Poon, A. W. P.; Arnquist, I. J.; Hoppe, E. W.; Kouzes, R. T.; LaFerriere, B. D.; Orrell, J. L.; Avignone, F. T.; Baldenegro-Barrera, C. X.; Bertrand, F. E.; and others

    2015-10-28

    The MAJORANA Collaboration is constructing the MAJORANA DEMONSTRATOR, an ultra-low background, modular, HPGe detector array with a mass of 44-kg (29 kg {sup 76}Ge and 15 kg {sup nat}Ge) to search for neutrinoless double beta decay in {sup 76}Ge. The next generation of tonne-scale Ge-based neutrinoless double beta decay searches will probe the neutrino mass scale in the inverted-hierarchy region. The MAJORANA DEMONSTRATOR is envisioned to demonstrate a path forward to achieve a background rate at or below 1 count/tonne/year in the 4 keV region of interest around the Q-value of 2039 keV. The MAJORANA DEMONSTRATOR follows a modular implementation to be easily scalable to the next generation experiment. First, the prototype module was assembled; it has been continuously taking data from July 2014 to June 2015. Second, Module 1 with more than half of the total enriched detectors and some natural detectors has been assembled and it is being commissioned. Finally, the assembly of Module 2, which will complete MAJORANA DEMONSTRATOR, is already in progress.

  12. The status and initial results of the MAJORANA DEMONSTRATOR

    NASA Astrophysics Data System (ADS)

    Zhu, Xiaoyu; MAJORANA Collaboration

    2017-01-01

    The MAJORANA DEMONSTRATOR is an ultra-low background experiment searching for neutrinoless double-beta decay in 76Ge at the Sanford Underground Research Facility. The search for neutrinoless double-beta decay could determine the Dirac vs Majorana nature of neutrino mass and provide insight to the matter-antimatter asymmetry in the Universe. The DEMONSTRATOR is comprised of 44.8 kg (30 kg enriched in 76Ge) of high purity Ge detectors separated into two modules. Construction and commissioning of both modules completed in Summer 2016 and both modules are now acquiring physics data. In my talk, I will discuss the initial results of the first physics run utilizing both modules focusing primarily on the studies of the background and projections to a ton-scale experiment. This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics, the Particle Astrophysics Program of the National Science Foundation, and the Sanford Underground Research Facility. We acknowledge the support of the U.S. Department of Energy through the LANL/LDRD Program.

  13. Analysis techniques for the evaluation of the neutrinoless double-β decay lifetime in 130Te with the CUORE-0 detector

    SciTech Connect

    Alduino, C.; Alfonso, K.; Artusa, D. R.; Azzolini, O.; Banks, T. I.; Bari, G.; Beeman, J. W.; Bellini, F.; Bersani, A.; Biassoni, M.; Brofferio, C.; Bucci, C.; Caminata, A.; Canonica, L.; Cao, X. G.; Capelli, S.; Cappelli, L.; Carbone, L.; Cardani, L.; Carniti, P.; Casali, N.; Cassina, L.; Chiesa, D.; Chott, N.; Clemenza, M.; Copello, S.; Cosmelli, C.; Cremonesi, O.; Creswick, R. J.; Cushman, J. S.; Dafinei, I.; Dally, A.; Davis, C. J.; Dell'Oro, S.; Deninno, M. M.; Di Domizio, S.; Di Vacri, M. L.; Drobizhev, A.; Fang, D. Q.; Faverzani, M.; Fernandes, G.; Ferri, E.; Ferroni, F.; Fiorini, E.; Freedman, S. J.; Fujikawa, B. K.; Giachero, A.; Gironi, L.; Giuliani, A.; Gladstone, L.; Gorla, P.; Gotti, C.; Gutierrez, T. D.; Haller, E. E.; Han, K.; Hansen, E.; Heeger, K. M.; Hennings-Yeomans, R.; Hickerson, K. P.; Huang, H. Z.; Kadel, R.; Keppel, G.; Kolomensky, Yu. G.; Lim, K. E.; Liu, X.; Ma, Y. G.; Maino, M.; Marini, L.; Martinez, M.; Maruyama, R. H.; Mei, Y.; Moggi, N.; Morganti, S.; Mosteiro, P. J.; Nones, C.; Norman, E. B.; Nucciotti, A.; O'Donnell, T.; Orio, F.; Ouellet, J. L.; Pagliarone, C. E.; Pallavicini, M.; Palmieri, V.; Pattavina, L.; Pavan, M.; Pessina, G.; Pettinacci, V.; Piperno, G.; Pirro, S.; Pozzi, S.; Previtali, E.; Rosenfeld, C.; Rusconi, C.; Sala, E.; Sangiorgio, S.; Santone, D.; Scielzo, N. D.; Singh, V.; Sisti, M.; Smith, A. R.; Taffarello, L.; Tenconi, M.; Terranova, F.; Tomei, C.; Trentalange, S.; Ventura, G.; Vignati, M.; Wagaarachchi, S. L.; Wang, B. S.; Wang, H. W.; Wilson, J.; Winslow, L. A.; Wise, T.; Woodcraft, A.; Zanotti, L.; Zhang, G. Q.; Zhu, B. X.; Zimmermann, S.; Zucchelli, S.

    2016-04-25

    Here, we describe in detail the methods used to obtain the lower bound on the lifetime of neutrinoless double-beta (0νββ) decay in 130Te and the associated limit on the effective Majorana mass of the neutrino using the CUORE-0 detector. CUORE-0 is a bolometric detector array located at the Laboratori Nazionali del Gran Sasso that was designed to validate the background reduction techniques developed for CUORE, a next-generation experiment scheduled to come online in 2016. CUORE-0 is also a competitive 0νββ decay search in its own right and functions as a platform to further develop the analysis tools and procedures to be used in CUORE. These include data collection, event selection and processing, as well as an evaluation of signal efficiency. In particular, we describe the amplitude evaluation, thermal gain stabilization, energy calibration methods, and the analysis event selection used to create our final 0νββ search spectrum. We define our high level analysis procedures, with emphasis on the new insights gained and challenges encountered. We outline in detail our fitting methods near the hypothesized 0νββ decay peak and catalog the main sources of systematic uncertainty. Finally, we derive the 0νββ decay half-life limits previously reported for CUORE-0, T1/2 > 2.7×1024yr, and in combination with the Cuoricino limit, T1/2 > 4.0×1024yr.

  14. Analysis techniques for the evaluation of the neutrinoless double-β decay lifetime in 130Te with the CUORE-0 detector

    DOE PAGES

    Alduino, C.; Alfonso, K.; Artusa, D. R.; ...

    2016-04-25

    Here, we describe in detail the methods used to obtain the lower bound on the lifetime of neutrinoless double-beta (0νββ) decay in 130Te and the associated limit on the effective Majorana mass of the neutrino using the CUORE-0 detector. CUORE-0 is a bolometric detector array located at the Laboratori Nazionali del Gran Sasso that was designed to validate the background reduction techniques developed for CUORE, a next-generation experiment scheduled to come online in 2016. CUORE-0 is also a competitive 0νββ decay search in its own right and functions as a platform to further develop the analysis tools and procedures tomore » be used in CUORE. These include data collection, event selection and processing, as well as an evaluation of signal efficiency. In particular, we describe the amplitude evaluation, thermal gain stabilization, energy calibration methods, and the analysis event selection used to create our final 0νββ search spectrum. We define our high level analysis procedures, with emphasis on the new insights gained and challenges encountered. We outline in detail our fitting methods near the hypothesized 0νββ decay peak and catalog the main sources of systematic uncertainty. Finally, we derive the 0νββ decay half-life limits previously reported for CUORE-0, T0ν1/2 > 2.7×1024yr, and in combination with the Cuoricino limit, T0ν1/2 > 4.0×1024yr.« less

  15. Limit on the radiative neutrinoless double electron capture of ^{36}Ar from GERDA Phase I

    NASA Astrophysics Data System (ADS)

    Agostini, M.; Allardt, M.; Bakalyarov, A. M.; Balata, M.; Barabanov, I.; Barros, N.; Baudis, L.; Bauer, C.; Bellotti, E.; Belogurov, S.; Belyaev, S. T.; Benato, G.; Bettini, A.; Bezrukov, L.; Bode, T.; Borowicz, D.; Brudanin, V.; Brugnera, R.; Caldwell, A.; Cattadori, C.; Chernogorov, A.; D'Andrea, V.; Demidova, E. V.; di Vacri, A.; Domula, A.; Doroshkevich, E.; Egorov, V.; Falkenstein, R.; Fedorova, O.; Freund, K.; Frodyma, N.; Gangapshev, A.; Garfagnini, A.; Gooch, C.; Grabmayr, P.; Gurentsov, V.; Gusev, K.; Hakenmüller, J.; Hegai, A.; Heisel, M.; Hemmer, S.; Heusser, G.; Hofmann, W.; Hult, M.; Inzhechik, L. V.; Csáthy, J. Janicskó; Jochum, J.; Junker, M.; Kazalov, V.; Kihm, T.; Kirpichnikov, I. V.; Kirsch, A.; Kish, A.; Klimenko, A.; Kneißl, R.; Knöpfle, K. T.; Kochetov, O.; Kornoukhov, V. N.; Kuzminov, V. V.; Laubenstein, M.; Lazzaro, A.; Lebedev, V. I.; Lehnert, B.; Liao, H. Y.; Lindner, M.; Lippi, I.; Lubashevskiy, A.; Lubsandorzhiev, B.; Lutter, G.; Macolino, C.; Majorovits, B.; Maneschg, W.; Medinaceli, E.; Miloradovic, M.; Mingazheva, R.; Misiaszek, M.; Moseev, P.; Nemchenok, I.; Palioselitis, D.; Panas, K.; Pandola, L.; Pelczar, K.; Pullia, A.; Riboldi, S.; Rumyantseva, N.; Sada, C.; Salamida, F.; Salathe, M.; Schmitt, C.; Schneider, B.; Schönert, S.; Schreiner, J.; Schütz, A.-K.; Schulz, O.; Schwingenheuer, B.; Selivanenko, O.; Shirchenko, M.; Simgen, H.; Smolnikov, A.; Stanco, L.; Stepaniuk, M.; Vanhoefer, L.; Vasenko, A. A.; Veresnikova, A.; von Sturm, K.; Wagner, V.; Walter, M.; Wegmann, A.; Wester, T.; Wiesinger, C.; Wilsenach, H.; Wojcik, M.; Yanovich, E.; Zhitnikov, I.; Zhukov, S. V.; Zinatulina, D.; Zuber, K.; Zuzel, G.

    2016-12-01

    Neutrinoless double electron capture is a process that, if detected, would give evidence of lepton number violation and the Majorana nature of neutrinos. A search for neutrinoless double electron capture of ^{36}Ar has been performed with germanium detectors installed in liquid argon using data from Phase I of the GERmanium Detector Array ( Gerda) experiment at the Gran Sasso Laboratory of INFN, Italy. No signal was observed and an experimental lower limit on the half-life of the radiative neutrinoless double electron capture of ^{36}Ar was established: T_{1/2} > 3.6 × 10^{21} years at 90% CI.

  16. Neutrinoless double-β decay and nuclear transition matrix elements

    SciTech Connect

    Rath, P. K.

    2015-10-28

    Within mechanisms involving the light Majorana neutrinos, squark-neutrino, Majorons, sterile neutrinos and heavy Majorana neutrino, nuclear transition matrix elements for the neutrinoless (β{sup −}β{sup −}){sub 0ν} decay of {sup 96}Zr, {sup 100}Mo, {sup 128,130}Te and {sup 150}Nd nuclei are calculated by employing the PHFB approach. Effects due to finite size of nucleons, higher order currents, short range correlations, and deformations of parent as well as daughter nuclei on the calculated matrix elements are estimated. Uncertainties in nuclear transition matrix elements within long-ranged mechanisms but for double Majoron accompanied (β{sup −}β{sup −}ϕϕ){sub 0ν} decay modes are 9%–15%. In the case of short ranged heavy Majorona neutrino exchange mechanism, the maximum uncertainty is about 35%. The maximum systematic error within the mechanism involving the exchange of light Majorana neutrino is about 46%.

  17. WLS R&D for the detection of noble gas scintillation at LBL: seeing the light from neutrinos, to dark matter, to double beta decay

    NASA Astrophysics Data System (ADS)

    Gehman, V. M.

    2013-09-01

    Radiation detectors with noble gasses as the active medium are becoming increasingly common in experimental programs searching for physics beyond the standard model. Nearly all of these experiments rely to some degree on collecting scintillation light from noble gasses. The VUV wavelengths associated with noble gas scintillation mean that most of these experiments use a fluorescent material to shift the direct scintillation light into the visible or near UV band. We present an overview of the R&D program at LBL related to noble gas detectors for neutrino physics, double beta decay, and dark matter. This program ranges from precise measurements of the fluorescence behavior of wavelength shifting films, to the prototyping of large are VUV sensitive light guides for multi-kiloton detectors.

  18. Resonant Enhancement of Neutrinoless Double-Electron Capture in Gd152

    NASA Astrophysics Data System (ADS)

    Eliseev, S.; Roux, C.; Blaum, K.; Block, M.; Droese, C.; Herfurth, F.; Kluge, H.-J.; Krivoruchenko, M. I.; Novikov, Yu. N.; Minaya Ramirez, E.; Schweikhard, L.; Shabaev, V. M.; Šimkovic, F.; Tupitsyn, I. I.; Zuber, K.; Zubova, N. A.

    2011-02-01

    In the search for the nuclide with the largest probability for neutrinoless double-electron capture, we have determined the Qγγ value between the ground states of Gd152 and Sm152 by Penning-trap mass-ratio measurements. The new Qγγ value of 55.70(18) keV results in a half-life of 1026yr for a 1 eV neutrino mass. With this smallest half-life among known 0νγγ transitions, Gd152 is a promising candidate for the search for neutrinoless double-electron capture.

  19. Separating double-beta decay events from solar neutrino interactions in a kiloton-scale liquid scintillator detector by fast timing

    NASA Astrophysics Data System (ADS)

    Elagin, Andrey; Frisch, Henry J.; Naranjo, Brian; Ouellet, Jonathan; Winslow, Lindley; Wongjirad, Taritree

    2017-03-01

    We present a technique for separating nuclear double beta decay (ββ -decay) events from background neutrino interactions due to 8B decays in the sun. This background becomes dominant in a kiloton-scale liquid-scintillator detector deep underground and is usually considered as irreducible due to an overlap in deposited energy with the signal. However, electrons from 0 νββ -decay often exceed the Cherenkov threshold in liquid scintillator, producing photons that are prompt and correlated in direction with the initial electron direction. The use of large-area fast photodetectors allows some separation of these prompt photons from delayed isotropic scintillation light and, thus, the possibility of reconstructing the event topology. Using a simulation of a 6.5 m radius liquid scintillator detector with 100 ps resolution photodetectors, we show that a spherical harmonics analysis of early-arrival light can discriminate between 0 νββ -decay signal and 8B solar neutrino background events on a statistical basis. Good separation will require the development of a slow scintillator with a 5 ns risetime.

  20. Transition operators entering neutrinoless double electron capture to excited nuclear states

    NASA Astrophysics Data System (ADS)

    Vergados, J. D.

    2011-10-01

    We construct the effective transition operators relevant for neutrinoless double electron capture leading to final nuclear states different than 0+. From the structure of these operators we see that if such a process is observed experimentally, it will be very helpful in singling out the very important light neutrino mass contribution from the other lepton violating mechanisms.

  1. New Nuclear Structure and Decay Results in the {sup 76}Ge–{sup 76}As System

    SciTech Connect

    Domula, A.R.; Gehre, D.; Zuber, K.; Drohé, J.C.; Nankov, N.; Plompen, A.J.M.; Rouki, C.; Stanoiu, M.; Klix, A.; Buffler, A.; Geduld, D.; Smit, F.D.; Vermeulen, C.; Maleka, P.; Newman, R.T.; Nolte, R.; Wallner, A.

    2014-06-15

    The process of neutrinoless double beta decay (0νββ) plays a key role in modern neutrino physics. Experiments on {sup 76}Ge 0νββ-decay using germanium semiconductors are at the forefront in this field. Due to the extremely low count rates expected for this rare decay, any kind of background event in the detector, especially at energies close to Qββ=2039.006 keV must be avoided. Therefore, a careful investigation on the neutron-induced background was carried out. In this scope experiments investigating the inelastic neutron excitation of the lower lying and the 69{sup th} excited level of {sup 76}Ge have been performed. The existence of a 2040.7 keV gamma-ray, that occurs by the de-excitation of the 69{sup th} excited level, was confirmed. Interfering background from {sup 68}Ge was studied via cross-section measurements of the {sup nat}Ge(n,jn){sup 68}Ge reaction using quasi-monoenergetic neutrons and accelerator mass specrometry for {sup 68}Ge detection. In order to explore the matrix element for the transition between the {sup 76}Ge-{sup 76}As ground states, the electron–capture of {sup 76}As has been measured for the first time.

  2. ({sup 3}He,t) reaction on the double {beta} decay nucleus {sup 48}Ca and the importance of nuclear matrix elements

    SciTech Connect

    Grewe, E.-W.; Frekers, D.; Rakers, S.; Baeumer, C.; Dohmann, H.; Thies, J.; Adachi, T.; Fujita, Y.; Shimbara, Y.; Botha, N. T.; Fujita, H.; Hatanaka, K.; Nakanishi, K.; Sakemi, Y.; Shimizu, Y.; Tameshige, Y.; Tamii, A.; Negret, A.; Popescu, L.; Neveling, R.

    2007-11-15

    High-resolution ({sup 3}He,t) measurements on the double {beta}-decay ({beta}{beta}) nucleus {sup 48}Ca have been performed at RCNP (Osaka, Japan) to determine Gamow-Teller (GT{sup -}) transitions to the nucleus {sup 48}Sc, which represents the intermediate nucleus in the second-order perturbative description of the {beta}{beta} decay. At a bombarding energy of E{sub {sup 3}He}=420 MeV an excitation energy resolution of 40 keV was achieved. The measurements were performed at two angle positions of the Grand Raiden Spectrometer (GRS): 0 deg. and 2.5 deg. The results of both settings were combined to achieve angular distributions, by which the character of single transitions could be determined. To characterize the different multipoles, theoretical angular distributions for states with J{sup {pi}}=1{sup +},2{sup +},2{sup -}, and 3{sup +} were calculated using the distorted-wave Born approximation (DWBA) Code DW81. The GT{sup -} strength was extracted up to E{sub x}=7 MeV and combined with corresponding GT{sup +} strength deduced from the {sup 48}Ti(d,{sup 2}He){sup 48}Sc data to calculate the low-energy part of the {beta}{beta}-decay matrix element for the {sup 48}Ca 2{nu}{beta}{beta} decay. We show that after applying trivial momentum corrections to the ({sup 3}He,t) spectrum, the two reaction probes (p,n) and ({sup 3}He,t) reveal a spectral response to an impressively high degree of similarity in the region of low momentum transfer.

  3. The role of g9/2 intruder state in the nuclear matrix elements of 76Ge → 76Se 2νββ(0+ → 0+) decay

    NASA Astrophysics Data System (ADS)

    Valencia, J. P.

    2016-07-01

    I propose a model for the upper-part of pf-shell, which consists of p1/2, p3/2, f5/2 and g9/2 single-particle orbits. While the pf-subshell (or d ˜s -subshell, i.e. η ˜=2 ,s˜1 /2,d˜3 /2,d˜5 /2) is governed by the SU˜S ˜T(4 )⊗U˜L ˜(6 ) symmetry, the g9/2 intruder state is governed by the seniority model. The nuclear states of 76Ge and 76Se are expressed as direct products of the d ˜s subshell component and the g-subshell one. The five-dimensional quasispin formalism with seniority zero restriction is used for a classification in the g-subshell. In the d ˜s -subshell, for each configuration [Mπ,Mν]d ˜s I choose only the most symmetric U˜L ˜(6 ) representations with total pseudo-spin S ˜=0 . Therefore, all the configurations are given by (0 Y 0 ˜) {4P2Y ˜} and (0 Y 0 -20 ˜) {4P +12Y -2 ˜} for 76Ge and 76Se, respectively with Y = 6-(nν - nπ)/2 and P = (4 - nπ)/2. I derive an explicit expression for the NME of the 2νββ(0+ → 0+) in the closure approximation.

  4. Production and test of isotopically modified Ge detectors for GERDA

    SciTech Connect

    Budjas, D.

    2011-07-01

    The viability of producing BEGe-type detectors from isotopically modified germanium for the GERDA experiment is demonstrated by a complete test of the supply chain. GERDA is built to search for neutrinoless double beta (0v{beta}{beta}) decay of Ge using high-purity germanium detectors made of material enriched in {sup 76}Ge. To reach a sensitivity for 0v{beta}{beta} decay of <1.4 x 10{sup 26} years, new active background suppression techniques are necessary. BEGe detectors enable a capability to efficiently identify and reject background events, while keeping large acceptance of 0v{beta}{beta} decay signal, by using novel pulse shape discrimination (PSD) techniques. The PSD as well as spectroscopic performance of prototype BEGe detectors from isotopically modified Ge was verified by comprehensive testing. (authors)

  5. Current experiments in germanium 0 ν β β search -- GERDA and MAJORANA

    NASA Astrophysics Data System (ADS)

    von Sturm, K.

    2015-01-01

    There are unanswered questions regarding neutrino physics that are of great interest for the scientific community. For example the absolute masses, the mass hierarchy and the nature of neutrinos are unknown up to now. The discovery of neutrinoless double beta decay (0νββ) would prove the existence of a Majorana mass, which would be linked to the half-life of the decay, and would in addition provide an elegant solution for the small mass of the neutrinos via the seesaw mechanism. Because of an existing discovery claim of 0νββ of 76Ge and the excellent energy resolution achievable, germanium is of special interest in the search for 0νββ . In this article the state of the art of germanium 0νββ search, namely the GERDA experiment and MAJORANA demonstrator, is presented. In particular, recent results of the GERDA collaboration, which strongly disfavour the above mentioned claim, are discussed.

  6. The MAJORANA Demonstrator Radioassay Program

    SciTech Connect

    Abgrall, N.; Arnquist, Isaac J.; Avignone, F. T.; Back, Henning O.; Barabash, Alexander S.; Bertrand, F.; Boswell, M.; Bradley, A. W.; Brudanin, V.; Busch, Matthew; Buuck, M.; Byram, D.; Caldwell, A. S.; Chan, Yuen-Dat; Christofferson, C. D.; Chu, P. H.; Cuesta, C.; Detwiler, Jason A.; Dunmore, J. A.; Efremenko, Yuri; Ejiri, H.; Elliott, S.; Finnerty, P.; Galindo-Uribarri, A.; Gehman, Victor M.; Gilliss, T.; Giovanetti, G. K.; Goett, J.; Green, M. P.; Gruszko, J.; Guinn, I.; Guiseppe, V. E.; Henning, R.; Hoppe, Eric W.; Howard, S.; Howe, M. A.; Jasinski, B. R.; Johnson, R. A.; Keeter, K.; Kidd, M. F.; Kochetov, Oleg; Konovalov, S.; Kouzes, Richard T.; Laferriere, Brian D.; Leon, Jonathan D.; Loach, J. C.; MacMullin, J.; MacMullin, S.; Martin, R. D.; Massarcyk, R.; Meijer, S. J.; Mertens, S.; Miller, M. L.; Orrell, John L.; O'Shaughnessy, C.; Overman, Nicole R.; Poon, Alan W.; Pushkin, K.; Radford, D. C.; Rager, J.; Rielage, Keith; Robertson, R. G. H.; Romero-Romero, E.; Ronquest, M. C.; Schubert, Alexis G.; Shanks, B.; Shirchenko, M.; Snavely, Kyle J.; Snyder, N.; Steele, David; Suriano, Anne-Marie; Tedeschi, D.; Trimble, J. E.; Varner, R. L.; Vasilyev, Sergey; Vetter, K.; Vorren, Kris R.; White, B. R.; Wilkerson, J. F.; Wiseman, C.; Xu, W.; Yakushev, E.; Yu, Chang-Hong; Yumatov, Vladimir; Zhitnikov, I.

    2016-05-03

    The Majorana collaboration is constructing the Majorana Demonstrator at the Sanford Underground Research Facility at the Homestake gold mine, in Lead, SD. The apparatus will use Ge detectors, enriched in isotope 76Ge, to demonstrate the feasibility of a large-scale Ge detector experiment to search for neutrinoless double beta decay. The long half-life of this postulated process requires that the apparatus be extremely low in radioactive isotopes whose decays may produce backgrounds to the search. The radioassay program conducted by the collaboration to ensure that the materials comprising the apparatus are suffciently pure is described. The resulting measurements of the radioactiveisotope contamination for a number of materials studied for use in the detector are reported.

  7. Cosmogenically-produced isotopes in natural and enriched high-purity germanium detectors for the MAJORANA DEMONSTRATOR

    NASA Astrophysics Data System (ADS)

    Gilliss, Thomas; MAJORANA DEMONSTRATOR Collaboration

    2017-01-01

    The MAJORANA DEMONSTRATOR advances toward measurements of the neutrinoless double-beta decay of 76Ge. Detectors employed in the DEMONSTRATOR are subject to cosmogenic spallation during production and processing, resulting in activation of certain long-lived radioisotopes. Activation of these cosmogenic isotopes is mitigated by shielded storage of detectors and through underground operation of the DEMONSTRATOR at the 4850 ft level of the Sanford Underground Research Facility. In this work, we explore the appearance and reduction of cosmogenic contributions to the DEMONSTRATOR background spectrum. This work is supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics, the Particle Astrophysics and Nuclear Physics Programs of the National Science Foundation, and the Sanford Underground Research Facility.

  8. The Majorana Demonstrator for 0νββ: Current Status and Future Plans

    SciTech Connect

    Green, Matthew P.; Avignone, F. T.; Galindo-Uribarri, Alfredo; Radford, David C; Romero-Romero, Elisa; Varner, Jr, Robert L; White, Brandon R; Wilkerson, J. F.

    2015-01-01

    The Majorana Demonstrator will search for neutrinoless-double-beta decay (0νββ) in 76Ge, while establishing the feasibility of a future tonne-scale germanium-based 0νββ experiment, and performing searches for new physics beyond the Standard Model. The experiment, currently under construction at the Sanford Underground Research Facility in Lead, SD, will consist of a pair of modular high-purity germanium detector arrays housed inside of a compact copper, lead, and polyethylene shield. Through a combination of strict materials qualifications and assay, low-background design, and powerful background rejection techniques, the Demonstrator aims to achieve a background rate in the 0νββ region of interest (ROI) of no more than 3cnts/(ROI-t-y). The current status of the Demonstrator is discussed, as are plans for its completion.

  9. The Majorana Parts Tracking Database

    DOE PAGES

    Abgrall, N.

    2015-01-16

    The Majorana Demonstrator is an ultra-low background physics experiment searching for the neutrinoless double beta decay of 76Ge. The Majorana Parts Tracking Database is used to record the history of components used in the construction of the Demonstrator. The tracking implementation takes a novel approach based on the schema-free database technology CouchDB. Transportation, storage, and processes undergone by parts such as machining or cleaning are linked to part records. Tracking parts provides a great logistics benefit and an important quality assurance reference during construction. In addition, the location history of parts provides an estimate of their exposure to cosmic radiation.more » In summary, a web application for data entry and a radiation exposure calculator have been developed as tools for achieving the extreme radio-purity required for this rare decay search.« less

  10. The Majorana Parts Tracking Database

    SciTech Connect

    Abgrall, N.; Aguayo, E.; Avignone, F. T.; Barabash, A. S.; Bertrand, F. E.; Brudanin, V.; Busch, M.; Byram, D.; Caldwell, A. S.; Chan, Y-D.; Christofferson, C. D.; Combs, D. C.; Cuesta, C.; Detwiler, J. A.; Doe, P. J.; Efremenko, Yu.; Egorov, V.; Ejiri, H.; Elliott, S. R.; Esterline, J.; Fast, J. E.; Finnerty, P.; Fraenkle, F. M.; Galindo-Uribarri, A.; Giovanetti, G. K.; Goett, J.; Green, M. P.; Gruszko, J.; Guiseppe, V. E.; Gusev, K.; Hallin, A. L.; Hazama, R.; Hegai, A.; Henning, R.; Hoppe, E. W.; Howard, S.; Howe, M. A.; Keeter, K. J.; Kidd, M. F.; Kochetov, O.; Konovalov, S. I.; Kouzes, R. T.; LaFerriere, B. D.; Leon, J. Diaz; Leviner, L. E.; Loach, J. C.; MacMullin, J.; Martin, R. D.; Meijer, S. J.; Mertens, S.; Miller, M. L.; Mizouni, L.; Nomachi, M.; Orrell, J. L.; O׳Shaughnessy, C.; Overman, N. R.; Petersburg, R.; Phillips, D. G.; Poon, A. W. P.; Pushkin, K.; Radford, D. C.; Rager, J.; Rielage, K.; Robertson, R. G. H.; Romero-Romero, E.; Ronquest, M. C.; Shanks, B.; Shima, T.; Shirchenko, M.; Snavely, K. J.; Snyder, N.; Soin, A.; Suriano, A. M.; Tedeschi, D.; Thompson, J.; Timkin, V.; Tornow, W.; Trimble, J. E.; Varner, R. L.; Vasilyev, S.; Vetter, K.; Vorren, K.; White, B. R.; Wilkerson, J. F.; Wiseman, C.; Xu, W.; Yakushev, E.; Young, A. R.; Yu, C. -H.; Yumatov, V.; Zhitnikov, I.

    2015-04-01

    The MAJORANA DEMONSTRATOR is an ultra-low background physics experiment searching for the neutrinoless double beta decay of 76Ge. The MAJORANA Parts Tracking Database is used to record the history of components used in the construction of the DEMONSTRATOR. Transportation, storage, and processes undergone by parts such as machining or cleaning are linked to part records. Tracking parts provides a great logistics benefit and an important quality assurance reference during construction. In addition, the location history of parts provides an estimate of their exposure to cosmic radiation. A web application for data entry and a radiation exposure calculator have been developed as tools for achieving the extreme radiopurity required for this rare decay search.

  11. A Dark Matter Search with MALBEK

    SciTech Connect

    Giovanetti, G. K.; Abgrall, N.; Aguayo, Estanislao; Avignone, Frank T.; Barabash, Alexander S.; Bertrand, F.; Boswell, M.; Brudanin, V.; Busch, Matthew; Byram, D.; Caldwell, A. S.; Chan, Yuen-Dat; Christofferson, Cabot-Ann; Combs, Dustin C.; Cuesta, C.; Detwiler, Jason A.; Doe, Peter J.; Efremenko, Yuri; Egorov, Viatcheslav; Ejiri, H.; Elliott, S. R.; Fast, James E.; Finnerty, P.; Fraenkle, Florian; Galindo-Uribarri, A.; Goett, J.; Green, M. P.; Gruszko, J.; Guiseppe, Vincente; Gusev, K.; Hallin, A. L.; Hazama, R.; Hegai, A.; Henning, Reyco; Hoppe, Eric W.; Howard, Stanley; Howe, M. A.; Keeter, K.; Kidd, M. F.; Kochetov, Oleg; Konovalov, S.; Kouzes, Richard T.; Laferriere, Brian D.; Leon, Jonathan D.; Leviner, L.; Loach, J. C.; MacMullin, J.; MacMullin, S.; Martin, R. D.; Meijer, S. J.; Mertens, S.; Nomachi, Masaharu; Orrell, John L.; O'Shaughnessy, C.; Overman, Nicole R.; Phillips, D.; Poon, Alan; Pushkin, K.; Radford, D. C.; Rager, J.; Rielage, Keith; Robertson, R. G. H.; Romero-Romero, E.; Ronquest, M. C.; Schubert, Alexis G.; Shanks, B.; Shima, T.; Shirchenko, M.; Snavely, Kyle J.; Snyder, N.; Suriano, Anne-Marie; Thompson, J.; Timkin, V.; Tornow, W.; Trimble, J. E.; Varner, R. L.; Vasilyev, Sergey; Vetter, Kai; Vorren, Kris R.; White, Brandon R.; Wilkerson, J. F.; Wiseman, C.; Xu, W.; Yakushev, E.; Young, A.; Yu, Chang-Hong; Yumatov, Vladimir

    2015-06-01

    The Majorana Demonstrator is an array of natural and enriched high purity germanium detectors that will search for the neutrinoless double-beta decay of 76Ge and perform a search for weakly interacting massive particles (WIMPs) with masses below 10 GeV. As part of the Majorana research and development efforts, we have deployed a modified, low-background broad energy germanium detector at the Kimballton Underground Research Facility. With its sub-keV energy threshold, this detector is potentially sensitive to non-Standard Model physics, including interactions with WIMPs. We discuss the backgrounds present in the WIMP region of interest and present results from a WIMP search with 221.49 live days of data from this detector.

  12. The MAJORANA DEMONSTRATOR for 0νββ: Current status and future plans

    SciTech Connect

    Green, M. P.; Abgrall, N.; Aguayo, E.; Avignone, III, F. T.; Barabash, A. S.; Bertrand, F. E.; Boswell, M.; Brudanin, V.; Busch, M.; Byram, D.; Caldwell, A. S.; Chan, Y. -D.; Christofferson, C. D.; Combs, D. C.; Cuesta, C.; Detwiler, J. A.; Doe, P. J.; Efremenko, Yu.; Egorov, V.; Ejiri, H.; Elliott, S. R.; Fast, J. E.; Finnerty, P.; Fraenkle, F. M.; Galindo-Uribarri, A.; Giovanetti, G. K.; Goett, J.; Gruszko, J.; Guiseppe, V. E.; Gusev, K.; Hallin, A. L.; Hazama, R.; Hegai, A.; Henning, R.; Hoppe, E. W.; Howard, S.; Howe, M. A.; Keeter, K. J.; Kidd, M. F.; Kochetov, O.; Konovalov, S. I.; Kouzes, R. T.; LaFerriere, B. D.; Leon, J.; Leviner, L. E.; Loach, J. C.; MacMullin, J.; MacMullin, S.; Martin, R. D.; Meijer, S.; Mertens, S.; Nomachi, M.; Orrell, J. L.; O'Shaughnessy, C.; Overman, N. R.; Phillips, II, D. G.; Poon, A. W.P.; Pushkin, K.; Radford, D. C.; Rager, J.; Rielage, K.; Robertson, R. G.H.; Romero-Romero, E.; Ronquest, M. C.; Schubert, A. G.; Shanks, B.; Shima, T.; Shirchenko, M.; Snavely, K. J.; Snyder, N.; Suriano, A. M.; Thompson, J.; Timkin, V.; Tornow, W.; Trimble, J. E.; Varner, R. L.; Vasilyev, S.; Vetter, K.; Vorren, K.; White, B. R.; Wilkerson, J. F.; Wiseman, C.; Xu, W.; Yakushev, E.; Young, A. R.; Yu, C. -H.; Yumatov, V.

    2015-01-01

    The Majorana Demonstrator will search for neutrinoless-double-beta decay (0νββ) in 76Ge, while establishing the feasibility of a future tonne-scale germanium-based 0νββ experiment, and performing searches for new physics beyond the Standard Model. The experiment, currently under construction at the Sanford Underground Research Facility in Lead, SD, will consist of a pair of modular high-purity germanium detector arrays housed inside of a compact copper, lead, and polyethylene shield. Through a combination of strict materials qualifications and assay, low-background design, and powerful background rejection techniques, the Demonstrator aims to achieve a background rate in the 0νββ region of interest (ROI) of no more than 3 counts in the 0νββ-decay ROI per tonne of target isotope per year (cnts/(ROI-t-y)). The current status of the Demonstrator is discussed, as are plans for its completion.

  13. Updated constraints on the light-neutrino exchange mechanisms of the 0νββ-decay

    NASA Astrophysics Data System (ADS)

    Štefánik, Dušan; Dvornický, Rastislav; Šimkovic, Fedor

    2015-10-01

    The neutrinoless double-beta (0νββ) decay associated with light neutrino exchange mechanisms, which are due to both left-handed V-A and right-handed V+A leptonic and hadronic currents, is discussed by using the recent progress achieved by the GERDA, EXO and KamlandZen experiments. The upper limits for effective neutrino mass mββ and the parameters <λ> and <η> characterizing the right handed current mechanisms are deduced from the data on the 0νββ-decay of 76Ge and 136Xe using nuclear matrix elements calculated within the nuclear shell model and quasiparticle random phase approximation and phase-space factors calculated with exact Dirac wave functions with finite nuclear size and electron screening. The careful analysis of upper constraints on effective lepton number violating parameters assumes a competition of the above mechanisms and arbitrary values of involved CP violating phases.

  14. The MAJORANA DEMONSTRATOR radioassay program

    NASA Astrophysics Data System (ADS)

    Abgrall, N.; Arnquist, I. J.; Avignone, F. T.; Back, H. O.; Barabash, A. S.; Bertrand, F. E.; Boswell, M.; Bradley, A. W.; Brudanin, V.; Busch, M.; Buuck, M.; Byram, D.; Caldwell, A. S.; Chan, Y.-D.; Christofferson, C. D.; Chu, P.-H.; Cuesta, C.; Detwiler, J. A.; Dunmore, J. A.; Efremenko, Yu.; Ejiri, H.; Elliott, S. R.; Finnerty, P.; Galindo-Uribarri, A.; Gehman, V. M.; Gilliss, T.; Giovanetti, G. K.; Goett, J.; Green, M. P.; Gruszko, J.; Guinn, I. S.; Guiseppe, V. E.; Henning, R.; Hoppe, E. W.; Howard, S.; Howe, M. A.; Jasinski, B. R.; Johnson, R. A.; Keeter, K. J.; Kidd, M. F.; Kochetov, O.; Konovalov, S. I.; Kouzes, R. T.; LaFerriere, B. D.; Leon, J.; Loach, J. C.; MacMullin, J.; MacMullin, S.; Martin, R. D.; Massarczyk, R.; Meijer, S.; Mertens, S.; Miller, M. L.; Orrell, J. L.; O'Shaughnessy, C.; Overman, N. R.; Poon, A. W. P.; Pushkin, K.; Radford, D. C.; Rager, J.; Rielage, K.; Robertson, R. G. H.; Romero-Romero, E.; Ronquest, M. C.; Schubert, A. G.; Shanks, B.; Shirchenko, M.; Snavely, K. J.; Snyder, N.; Steele, D.; Suriano, A. M.; Tedeschi, D.; Trimble, J. E.; Varner, R. L.; Vasilyev, S.; Vetter, K.; Vorren, K.; White, B. R.; Wilkerson, J. F.; Wiseman, C.; Xu, W.; Yakushev, E.; Yu, C.-H.; Yumatov, V.; Zhitnikov, I.

    2016-08-01

    The MAJORANA collaboration is constructing the MAJORANA DEMONSTRATOR at the Sanford Underground Research Facility at the Homestake gold mine, in Lead, SD. The apparatus will use Ge detectors, enriched in isotope 76Ge, to demonstrate the feasibility of a large-scale Ge detector experiment to search for neutrinoless double beta decay. The long half-life of this postulated process requires that the apparatus be extremely low in radioactive isotopes whose decays may produce backgrounds to the search. The radioassay program conducted by the collaboration to ensure that the materials comprising the apparatus are sufficiently pure is described. The resulting measurements from gamma-ray counting, neutron activation and mass spectroscopy of the radioactive-isotope contamination for the materials studied for use in the detector are reported. We interpret these numbers in the context of the expected background for the experiment.

  15. Low background signal readout electronics for the Majorana Demonstrator

    DOE PAGES

    Guinn, I.; Abgrall, N.; Avignone, F. T.; ...

    2015-05-01

    The Majorana Demonstrator is a planned 40 kg array of Germanium detectors intended to demonstrate the feasibility of constructing a tonne-scale experiment that will seek neutrinoless double beta decay (0νββ) in 76Ge. In such an experiment we require backgrounds of less than 1 count/tonne-year in the 4 keV region of interest around the 2039 keV Q-value of the ββ decay. Moreover, designing low-noise electronics, which must be placed in close proximity to the detectors, presents a challenge to reaching this background target. Finally, this paper will discuss the Majorana collaboration's solutions to some of these challenges.

  16. The Majorana Demonstrator radioassay program

    DOE PAGES

    Abgrall, N.; Arnquist, I. J.; Avignone, F. T.; ...

    2016-05-03

    The Majorana collaboration is constructing the Majorana Demonstrator at the Sanford Underground Research Facility at the Homestake gold mine, in Lead, SD. The apparatus will use Ge detectors, enriched in isotope 76Ge, to demonstrate the feasibility of a large-scale Ge detector experiment to search for neutrinoless double beta decay. The long half-life of this postulated process requires that the apparatus be extremely low in radioactive isotopes whose decays may produce backgrounds to the search. The radioassay program conducted by the collaboration to ensure that the materials comprising the apparatus are sufficiently pure is described. The resulting measurements from gamma-ray counting,more » neutron activation and mass spectroscopy of the radioactive-isotope contamination for the materials studied for use in the detector are reported. In conclusion, we interpret these numbers in the context of the expected background for the experiment.« less

  17. Analysis techniques for background rejection at the MAJORANA DEMONSTRATOR

    SciTech Connect

    Cuesta, C.; Buuck, M.; Detwiler, J. A.; Gruszko, J.; Guinn, I. S.; Leon, J.; Robertson, R. G. H.; Abgrall, N.; Bradley, A. W.; Chan, Y-D.; Mertens, S.; Poon, A. W. P.; Arnquist, I. J.; Hoppe, E. W.; Kouzes, R. T.; LaFerriere, B. D.; Orrell, J. L.; Avignone, F. T.; Baldenegro-Barrera, C. X.; Bertrand, F. E.; and others

    2015-08-17

    The MAJORANA Collaboration is constructing the MAJORANA DEMONSTRATOR, an ultra-low background, 40- kg modular HPGe detector array to search for neutrinoless double beta decay in {sup 76}Ge. In view of the next generation of tonne-scale Ge-based 0νβ β-decay searches that will probe the neutrino mass scale in the inverted-hierarchy region, a major goal of the MAJORANA DEMONSTRATOR is to demonstrate a path forward to achieving a background rate at or below 1 count/tonne/year in the 4 keV region of interest around the Q-value at 2039 keV. The background rejection techniques to be applied to the data include cuts based on data reduction, pulse shape analysis, event coincidences, and time correlations. The Point Contact design of the DEMONSTRATOR’s germanium detectors allows for significant reduction of gamma background.

  18. Results from phase I of the GERDA experiment

    SciTech Connect

    Wester, Thomas

    2015-10-28

    The GERmanium Detector Array Gerda at the Laboratori Nazionali del Gran Sasso of the INFN in Italy is an experiment dedicated to the search for the neutrinoless double beta (0νββ) decay in {sup 76}Ge. The experiment employs high purity germanium detectors enriched in {sup 76}Ge inside a 64 m{sup 3} cryostat filled with liquid argon. Gerda was planned in two phases of data taking with the goal to reach a half-life sensitivity in the order of 10{sup 26} yr. Phase I of Gerda was running from November 2011 until May 2013. With about 18 kg total detector mass, data with an exposure of 21.6 kg·yr was collected and a background index of 0.01 cts/(keV·kg·yr) was achieved in the region of interest. No signal was found for the 0νββ decay and a new limit of T{sub 1/2} > 2.1 · 10{sup 25} yr (90% C.L.) was obtained, strongly disfavoring the previous claim of observation. Furthermore, the 2νββ decay half-life of {sup 76}Ge was measured with unprecedented precision. Other results include new half-life limits of the order of 10{sup 23} yr for Majoron emitting double beta decay modes with spectral indices n = 1, 2, 3, 7 and new limits in the order of 10{sup 23} yr for 2νββ decays to the first 3 excited states of {sup 76}Se. In Phase II, currently in preparation, the detector mass will be doubled while reducing the background index by a factor of 10.

  19. Large-volume ultralow background germanium-germanium coincidence/anticoincidence gamma-ray spectrometer

    SciTech Connect

    Brodzinski, R.L.; Brown, D.P.; Evans, J.C. Jr.; Hensley, W.K.; Reeves, J.H.; Wogman, N.A.; Avignone, F.T. III; Miley, H.S.; Moore, R.S.

    1984-03-01

    A large volume (approx. 1440 cm/sup 3/), multicrystal, high resolution intrinsic germanium gamma-ray spectrometer has been designed based on 3 generations of experiments. The background from construction materials used in standard commercial configurations has been reduced by at least two orders of magnitude. Data taken with a 132 cm/sup 3/ prototype detector, installed in the Homestake Gold Mine, are presented. The first application of the full scale detector will be an ultrasensitive search for neutrinoless and two-neutrino double beta decay of /sup 76/Ge. The size and geometrical configuration of the crystals is chosen to optimize detection of double decay to the first excited state of /sup 76/Se with subsequent emission of a 559 keV gamma ray. The detector will be sufficiently sensitive for measuring the neutrinoless double beta decay to the ground state to establish a minimum half life of 1.4.10/sup 24/ y. Application of the large spectrometer system to the analysis of low level environmental and biological samples is discussed.

  20. MaGe-a Geant4-Based Monte Carlo Application Framework for Low-Background Germanium Experiments

    SciTech Connect

    Boswell, Melissa; Chan, Yuen-Dat; Detwiler, Jason A.; Finnerty, Padraic; Henning, Reyco; Gehman, Victor M.; Johnson, Rob A.; Jordan, David V.; Kazkaz, Kareem; Knapp, Markus; Kroninger, Kevin; Lenz, Daniel; Leviner, Lance; Liu, Jing; Liu, Xiang; MacMullin, Sean; Marino, Michael G.; Mokhtarani, Akbar; Pandola, Luciano; Schubert, Alexis G.; Schubert, Jens; Tomei, Claudia; Volynets, Oleksandr

    2011-06-01

    We describe a physics simulation software framework, MAGE, that is based on the GEANT4 simulation toolkit. MAGE is used to simulate the response of ultra-low radioactive background radiation detectors to ionizing radiation, specifically the MAJ ORANA and GE RDA neutrinoless double-beta decay experiments. MAJ ORANA and GERDA use high-purity germanium technology to search for the neutrinoless double-beta decay of the 76 Ge isotope, and MAGE is jointly developed between these two collaborations. The MAGE framework contains simulated geometries of common objects, prototypes, test stands, and the actual experiments. It also implements customized event generators, GE ANT 4 physics lists, and output formats. All of these features are available as class libraries that are typically compiled into a single executable. The user selects the particular experimental setup implementation at run-time via macros. The combination of all these common classes into one framework reduces duplication of efforts, eases comparison between simulated data and experiment, and simplifies the addition of new detectors to be simulated. This paper focuses on the software framework, custom event generators, and physics list.

  1. Status and Initial Results from the MAJORANA DEMONSTRATOR

    NASA Astrophysics Data System (ADS)

    Detwiler, Jason

    2016-09-01

    The MAJORANA DEMONSTRATOR is performing a sensitive search for the neutrinoless double-beta decay of 76Ge using an ultra-low background array of enriched HPGe detectors deployed at the Sanford Underground Research Facility in Lead, SD. This rare process is generically predicted to occur by large classes of beyond-the-Standard-Model theories, and its observation would indicate that lepton number is not a conserved quantity in nature, with implications for the matter-dominance of the universe. The techniques used for the MAJORANA DEMONSTRATOR include selection and production of materials extremely low in natural radioactivity, choice of detector technology enabling active rejection of background, and graded active and passive shielding, which together give a projected background rate that is the lowest among existing techniques. First data from the DEMONSTRATOR is in-hand, and I will present our preliminary background performance and sensitivity both to neutrinoless double-beta decay as well as other physics targets. I will discuss the current detector status and plans for future upgrades, and our ultimate goal to field a much larger array with even lower background that will be sensitive to MAJORANA neutrinos with an inverted mass ordering.

  2. Astroparticle physics with a customized low-background broad energy Germanium detector

    SciTech Connect

    Aalseth, Craig E.; Amman, M.; Avignone, Frank T.; Back, Henning O.; Barabash, Alexander S.; Barbeau, P. S.; Bergevin, M.; Bertrand, F.; Boswell, M.; Brudanin, V.; Bugg, William; Burritt, Tom H.; Busch, Matthew; Capps, Greg L.; Chan, Yuen-Dat; Collar, J. I.; Cooper, R. J.; Creswick, R.; Detwiler, Jason A.; Diaz, J.; Doe, Peter J.; Efremenko, Yuri; Egorov, Viatcheslav; Ejiri, H.; Elliott, Steven R.; Ely, James H.; Esterline, James H.; Farach, H. A.; Fast, James E.; Fields, N.; Finnerty, P.; Fujikawa, Brian; Fuller, Erin S.; Gehman, Victor M.; Giovanetti, G. K.; Guiseppe, Vincente; Gusey, K.; Hallin, A. L.; Harper, Gregory; Hazama, R.; Henning, Reyco; Hime, Andrew; Hoppe, Eric W.; Hossbach, Todd W.; Howe, M. A.; Johnson, R. A.; Keeter, K.; Keillor, Martin E.; Keller, C.; Kephart, Jeremy D.; Kidd, Mary; Knecht, A.; Kochetov, Oleg; Konovalov, S.; Kouzes, Richard T.; Leviner, L.; Loach, J. C.; Luke, P.; MacMullin, S.; Marino, Michael G.; Martin, R. D.; Mei, Dong-Ming; Miley, Harry S.; Miller, M. L.; Mizouni, Leila; Myers, Allan W.; Nomachi, Masaharu; Orrell, John L.; Peterson, David; Phillips, D.; Poon, Alan; Prior, Gersende; Qian, J.; Radford, D. C.; Rielage, Keith; Robertson, R. G. H.; Rodriguez, Larry; Rykaczewski, Krzysztof P.; Salazar, Harold; Schubert, Alexis G.; Shima, T.; Shirchenko, M.; Steele, David; Strain, J.; Swift, Gary; Thomas, K.; Timkin, V.; Tornow, W.; Van Wechel, T. D.; Vanyushin, I.; Varner, R. L.; Vetter, Kai; Wilkerson, J. F.; Wolfe, B. A.; Xiang, W.; Yakushev, E.; Yaver, Harold; Young, A.; Yu, Chang-Hong; Yumatov, Vladimir; Zhang, C.; Zimmerman, S.

    2011-10-01

    The Majorana Collaboration is building the Majorana Demonstrator, a 60 kg array of high purity germanium detectors housed in an ultra-low background shield at the Sanford Underground Laboratory in Lead, SD. The Majorana Demonstrator will search for neutrinoless double-beta decay of 76Ge while demonstrating the feasibility of a tonne-scale experiment. It may also carry out a dark matter search in the 1-10 GeV/c² mass range. We have found that customized Broad Energy Germanium (BEGe) detectors produced by Canberra have several desirable features for a neutrinoless double-beta decay experiment, including low electronic noise, excellent pulse shape analysis capabilities, and simple fabrication. We have deployed a customized BEGe, the Majorana Low-Background BEGe at Kimballton (MALBEK), in a low-background cryostat and shield at the Kimballton Underground Research Facility in Virginia. This paper will focus on the detector characteristics and measurements that can be performed with such a radiation detector in a low-background environment.

  3. Double resonant enhancement in the neutrinoless double-electron capture of 190Pt

    NASA Astrophysics Data System (ADS)

    Eibach, M.; Bollen, G.; Gulyuz, K.; Izzo, C.; Redshaw, M.; Ringle, R.; Sandler, R.; Valverde, A. A.

    2016-07-01

    Background: The observation of neutrinoless double-β transitions would indicate physics beyond the standard model as the lepton number conservation is violated. For a complete degeneracy in the energy of the initial and final states, the neutrinoless double-electron capture is resonantly enhanced. This shortens the half-life to similar orders of magnitude as the neutrinoless double-β decay and expands the set of nuclei for the search of neutrinoless double-β transitions as the observation of either process would be equally likely. Purpose: To clearly identify transitions that are resonantly enhanced, among other parameters the total energy of the decay, Qɛ ɛ, needs to be measured very precisely. Of the 12 initially identified candidates, the last remaining decay without a precise Qɛ ɛ was 190Pt(0 ν ɛ ɛ )190Os . Method: The Qɛ ɛ value was determined with the Penning trap mass spectrometer LEBIT by measuring the ratio of the cyclotron frequencies of +190Pt and +190Os in a 9.4-T superconducting magnet. Result: The Qɛ ɛ value was determined to be 1401.57(47) keV with an uncertainty reduction of an order of magnitude compared to its previously known value. The absolute value is shifted by 17.17(623) keV relative to the previously accepted one. Furthermore, the mass value of 190Pt was found to be shifted by more than three standard deviations. In addition we improved the mass values for Os,190186 and 194Pt. Conclusion: Transitions to the two nuclear excited states of 190Os with 1326.9(5) and 1387.00(2) keV energy were identified to be resonantly enhanced within a 1 σ uncertainty. The significantly reduced uncertainty of Qɛ ɛ confirmed the potential for a resonantly enhanced transition.

  4. Results of experiments devoted to searches for 2K capture on {sup 78}Kr and for the double-beta decay of {sup 136}Xe with the aid of proportional counters

    SciTech Connect

    Gavrilyuk, Yu. M.; Gangapshev, A. M.; Zhantudueva, Dj. A.; Kazalov, V. V.; Kuz'minov, V. V.; Panasenko, S. I.; Ratkevich, S. S.; Efendiev, K. V.; Yakimenko, S. P.

    2013-09-15

    A brief description of two low-background setups deployed at the Baksan Neutrino Observatory (Institute for Nuclear Research, Russian Academy of Sciences) and intended for searches for two types of double-beta decay of inert-gas isotopes-2K capture on {sup 78}Kr and the double-beta decay of {sup 136}Xe-is given. The two setups in question have similar structures and employ identical large high-pressure copper proportional counters as detectors. Upon a treatment of data from measurements with krypton samples differing in the content of the isotope {sup 78}Kr, the spectrum for an enriched sample revealed an excess of events at a statistical-significance level of about two standard deviations (2{sigma}). If one attributes this excess to 2K(2{nu}) capture on {sup 78}Kr, the respective half-life is T{sub 1/2} = 1.4{sub -0.7}{sup +2.3} Multiplication-Sign 10{sup 22} yr at a 90% C.L. A treatment of data from measurements with xenon samples differing in content of the isotope {sup 136}Xe led to the appearance of an excess of events in the spectrum for an enriched sample at a statistical-significance level of about 2.2{sigma}. If one assumes that this excess is due to the two-neutrino double-beta decay of {sup 136}Xe, then the respective half-life is T{sub 1/2} = 5.8{sub -1.8}{sup +4.7} Multiplication-Sign 10{sup 21} yr.

  5. A high-resolution CMOS imaging detector for the search of neutrinoless double β decay in 82Se

    NASA Astrophysics Data System (ADS)

    Chavarria, A. E.; Galbiati, C.; Li, X.; Rowlands, J. A.

    2017-03-01

    We introduce high-resolution solid-state imaging detectors for the search of neutrinoless double β decay. Based on the present literature, imaging devices from amorphous 82Se evaporated on a complementary metal-oxide-semiconductor (CMOS) active pixel array could have the energy and spatial resolution to produce two-dimensional images of ionizing tracks of utmost quality, effectively akin to an electronic bubble chamber in the double β decay energy regime. Still to be experimentally demonstrated, a detector consisting of a large array of these devices could have very low backgrounds, possibly reaching 1 × 10‑7/(kgy) in the neutrinoless decay region of interest (ROI), as it may be required for the full exploration of the neutrinoless double β decay parameter space in the most unfavorable condition of a strongly quenched nucleon axial coupling constant.

  6. Rearrangement of valence neutrons in the neutrinoless double-β decay of 136Xe

    NASA Astrophysics Data System (ADS)

    Szwec, S. V.; Kay, B. P.; Cocolios, T. E.; Entwisle, J. P.; Freeman, S. J.; Gaffney, L. P.; Guimarães, V.; Hammache, F.; McKee, P. P.; Parr, E.; Portail, C.; Schiffer, J. P.; de Séréville, N.; Sharp, D. K.; Smith, J. F.; Stefan, I.

    2016-11-01

    A quantitative description of the change in ground-state neutron occupancies between 136Xe and 136Ba, the initial and final state in the neutrinoless double-β decay of 136Xe, has been extracted from precision measurements of the cross sections of single-neutron-adding and -removing reactions. Comparisons are made to recent theoretical calculations of the same properties using various nuclear-structure models. These are the same calculations used to determine the magnitude of the nuclear matrix elements for the process, which at present disagree with each other by factors of 2 or 3. The experimental neutron occupancies show some disagreement with the theoretical calculations.

  7. Rearrangement of valence neutrons in the neutrinoless double-β decay of Xe136

    DOE PAGES

    Szwec, S. V.; Kay, B. P.; Cocolios, T. E.; ...

    2016-11-15

    Here, a quantitative description of the change in ground-state neutron occupancies between 136Xe and 136Ba, the initial and final state in the neutrinoless double-β decay of 136Xe, has been extracted from precision measurements of the cross sections of single-neutron-adding and -removing reactions. Comparisons are made to recent theoretical calculations of the same properties using various nuclear-structure models. These are the same calculations used to determine the magnitude of the nuclear matrix elements for the process, which at present disagree with each other by factors of 2 or 3. The experimental neutron occupancies show some disagreement with the theoretical calculations.

  8. Cosmogenic Induced Background Estimation for the MAJORANA DEMONSTRATOR Experiment

    NASA Astrophysics Data System (ADS)

    White, Brandon; Majorana Collaboration

    2016-09-01

    Neutrino-less double beta (0 νββ) decay experiments probe for such rare events that the suppression and understanding of backgrounds are major experimental concerns. Cosmogenic induced isotopes have the potential to be a major background for such experiments. For the MAJORANA DEMONSTRATOR Experiment 76Ge isotope is used as both detector and source and pure electroformed copper is primarily used for detector housing. The isotopes 68Ge and 60Co are cosmogenically produced when the Germanium and Copper components are near Earth's surface. The decay of these isotopes can mimic events in the region of interest. The experiment is located at the 4850 foot level at the Sanford Underground Research Facility in Lead, South Dakota to suppress cosmogenic activation. In this talk I will present the calculations of cosmogenic backgrounds for the enriched 76Ge and electroformed Copper materials used in the MAJORANA DEMONSTRATOR. The activation is determined by the surface exposure time of materials. This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics, the Particle Astrophysics and Nuclear Physics Programs of the National Science Foundation, and the Sanford Underground Research Facility.

  9. Low Background Signal Readout Electronics for the MAJORANA DEMONSTRATOR

    SciTech Connect

    Guinn, I.; Abgrall, N.; Arnquist, Isaac J.; Avignone, Frank T.; Baldenegro-Barrera, C. X.; Barabash, Alexander S.; Bertrand, F.; Bradley, A. W.; Brudanin, V.; Busch, Matthew; Buuck, M.; Byram, D.; Caldwell, A. S.; Chan, Yuen-Dat; Christofferson, C. D.; Cuesta, C.; Detwiler, Jason A.; Efremenko, Yuri; Ejiri, H.; Elliott, Steven R.; Galindo-Uribarri, A.; Gilliss, T.; Giovanetti, G. K.; Goett, J.; Green, M. P.; Gruszko, J.; Guiseppe, V. E.; Henning, Reyco; Hoppe, Eric W.; Howard, Stanley; Howe, M. A.; Jasinski, B. R.; Keeter, K.; Kidd, M. F.; Konovalov, S.; Kouzes, Richard T.; Laferriere, Brian D.; Leon, Jonathan D.; MacMullin, J.; Martin, R. D.; Meijer, S. J.; Mertens, S.; Orrell, John L.; O'Shaughnessy, C.; Poon, Alan; Radford, D. C.; Rager, J.; Rielage, Keith; Robertson, R. G. H.; Romero-Romero, E.; Shanks, B.; Shirchenko, M.; Snyder, N.; Suriano, Anne-Marie; Tedeschi, D.; Trimble, J. E.; Varner, R. L.; Vasilyev, Sergey; Vetter, Kai; Vorren, Kris R.; White, Brandon R.; Wilkerson, J. F.; Wiseman, C.; Xu, W.; Yakushev, E.; Yu, Chang-Hong; Yumatov, Vladimir; Zhitnikov, I.

    2015-03-18

    The Majorana Demonstrator (MJD)[1] is an array of p-type point contact (PPC) high purity Germanium (HPGe) detectors intended to search for neutrinoless double beta decay (0vBB decay) in 76Ge. MJD will consist of 40 kg of detectors, 30 kg of which will be isotopically enriched to 87% 76Ge. The array will consist of 14 strings of four or ve detectors placed in two separate cryostats. One of the main goals of the experiment is to demonstrate the feasibility of building a tonne-scale array of detectors to search for 0vBB decay with a much higher sensitivity. This involves acheiving backgrounds in the 4 keV region of interest (ROI) around the 2039 keV Q-value of the BB decay of less than 1 count/ROI-t-y. Because many backgrounds will not directly scale with detector mass, the specific background goal of MJD is less than 3 counts/ROI-t-y.

  10. Status of the GERDA Phase II upgrade

    NASA Astrophysics Data System (ADS)

    Wagner, Victoria

    2016-06-01

    The GERDA experiment is designed to search for neutrinoless double beta (0νββ) decay of 76Ge. In Phase I of the experiment a background index of 10-2 cts/(keV.kg.yr) was reached. A lower limit on the half-life of the 0νββ decay of 76Ge was set to 2.1.1025 yr (at 90% C.L.). The aim of Phase II is to reach a sensitivity of the half-life of about 1026 yr. To increase the exposure thirty new Broad Energy Germanium (BEGe) detectors have been produced. These detectors are distinct for their improved energy resolution and enhanced pulse shape discrimination of signal from background events. Further background reduction will be reached by a light instrumentation to read out argon scintillation light. In April 2015 the light instrumentation together with eight BEGe detectors has been successfully deployed in the GERDA cryostat. In a commissioning run it was shown that two of the major background components, external γ-rays from 214Bi and 208Tl decays, were suppressed up to two orders of magnitude. We are confident to reach a background index of 10-3 cts/(keV.kg.yr) which is the design goal for GERDA Phase II.

  11. Examination of the possible enhancement of neutrinoless double-electron capture in 78Kr

    NASA Astrophysics Data System (ADS)

    Bustabad, S.; Bollen, G.; Brodeur, M.; Lincoln, D. L.; Novario, S. J.; Redshaw, M.; Ringle, R.; Schwarz, S.

    2013-09-01

    Penning-trap mass spectrometry was used at the Low-Energy Beam and Ion Trap (LEBIT) facility at the National Superconducting Cyclotron Laboratory (NSCL) to investigate 78Kr, a candidate for resonantly enhanced neutrinoless double-electron capture (0νECEC). The newly determined Q value of 2847.75 (27) keV is 1.4 keV greater than the value from the most recent atomic mass evaluation [Chin. Phys. C1674-113710.1088/1674-1137/36/12/003 36, 1603 (2012)], a change of two sigma, and the uncertainty has been reduced by a factor of three. The change in the Q value shifts allowed 0νECEC in 78Kr further from resonant enhancement. With the improved determination of the Q value, all known excited states can now be confidently excluded from possible 78Se candidates that could lead to resonantly enhanced 0νECEC.

  12. HEROICA: an underground facility for the fast screening of germanium detectors

    NASA Astrophysics Data System (ADS)

    Andreotti, E.; Garfagnini, A.; Maneschg, W.; Barros, N.; Benato, G.; Brugnera, R.; Costa, F.; Falkenstein, R.; Guthikonda, K. K.; Hegai, A.; Hemmer, S.; Hult, M.; Jänner, K.; Kihm, T.; Lehnert, B.; Liao, H.; Lubashevskiy, A.; Lutter, G.; Marissens, G.; Modenese, L.; Pandola, L.; Reissfelder, M.; Sada, C.; Salathe, M.; Schmitt, C.; Schulz, O.; Schwingenheuer, B.; Turcato, M.; Ur, C.; von Sturm, K.; Wagner, V.; Westermann, J.

    2013-06-01

    HEROICA (Hades Experimental Research Of Intrinsic Crystal Appliances) is an infrastructure to characterize germanium detectors and has been designed and constructed at the HADES Underground Research Laboratory, located in Mol (Belgium). Thanks to the 223 m overburden of clay and sand, the muon flux is lowered by four orders of magnitude. This natural shield minimizes the exposure of radio-pure germanium material to cosmic radiation resulting in a significant suppression of cosmogenic activation in the germanium detectors. The project has been strongly motivated by a special production of germanium detectors for the GERDA experiment. GERDA, currently collecting data at the Laboratori Nazionali del Gran Sasso of INFN, is searching for the neutrinoless double beta decay of 76Ge. In the near future, GERDA will increase its mass and sensitivity by adding new Broad Energy Germanium (BEGe) detectors. The production of the BEGe detectors is done at Canberra in Olen (Belgium), located about 30 km from the underground test site. Therefore, HADES is used both for storage of the crystals over night, during diode production, and for the characterization measurements. A full quality control chain has been setup and tested on the first seven prototype detectors delivered by the manufacturer at the beginning of 2012. The screening capabilities demonstrate that the installed setup fulfills a fast and complete set of measurements on the diodes and it can be seen as a general test facility for the fast screening of high purity germanium detectors. The results are of major importance for a future massive production and characterization chain of germanium diodes foreseen for a possible next generation 1-tonne double beta decay experiment with 76Ge.

  13. Neutrino propagation in nuclear medium and neutrinoless double-β decay.

    PubMed

    Kovalenko, S; Krivoruchenko, M I; Simkovic, F

    2014-04-11

    We discuss a novel effect in neutrinoless double-β (0νββ) decay related with the fact that its underlying mechanisms take place in the nuclear matter environment. We study the neutrino exchange mechanism and demonstrate the possible impact of nuclear medium via lepton-number-violating (LNV) four-fermion interactions of neutrinos with quarks from a decaying nucleus. The net effect of these interactions is the generation of an effective in-medium Majorana neutrino mass matrix. The enhanced rate of the 0νββ decay can lead to the apparent incompatibility of observations of the 0νββ decay with the value of the neutrino mass determined or restricted by the β-decay and cosmological data. The effective neutrino masses and mixing are calculated for the complete set of the relevant four-fermion neutrino-quark operators. Using experimental data on the 0νββ decay in combination with the β-decay and cosmological data, we evaluate the characteristic scales of these operators: ΛLNV≥2.4  TeV.

  14. Nuclear matrix element of neutrinoless double-β decay: Relativity and short-range correlations

    NASA Astrophysics Data System (ADS)

    Song, L. S.; Yao, J. M.; Ring, P.; Meng, J.

    2017-02-01

    Background:The discovery of neutrinoless double-β (0 ν β β ) decay would demonstrate the nature of neutrinos, have profound implications for our understanding of matter-antimatter mystery, and solve the mass hierarchy problem of neutrinos. The calculations for the nuclear matrix elements M0 ν of 0 ν β β decay are crucial for the interpretation of this process. Purpose: We study the effects of relativity and nucleon-nucleon short-range correlations on the nuclear matrix elements M0 ν by assuming the mechanism of exchanging light or heavy neutrinos for the 0 ν β β decay. Methods:The nuclear matrix elements M0 ν are calculated within the framework of covariant density functional theory, where the beyond-mean-field correlations are included in the nuclear wave functions by configuration mixing of both angular-momentum and particle-number projected quadrupole deformed mean-field states. Results: The nuclear matrix elements M0 ν are obtained for ten 0 ν β β -decay candidate nuclei. The impact of relativity is illustrated by adopting relativistic or nonrelativistic decay operators. The effects of short-range correlations are evaluated. Conclusions: The effects of relativity and short-range correlations play an important role in the mechanism of exchanging heavy neutrinos though the influences are marginal for light neutrinos. Combining the nuclear matrix elements M0 ν with the observed lower limits on the 0 ν β β -decay half-lives, the predicted strongest limits on the effective masses are ||<0.06 eV for light neutrinos and | |-1>3.065 ×108GeV for heavy neutrinos.

  15. Relativistic description of nuclear matrix elements in neutrinoless double-β decay

    NASA Astrophysics Data System (ADS)

    Song, L. S.; Yao, J. M.; Ring, P.; Meng, J.

    2014-11-01

    Background: Neutrinoless double-β (0 ν β β ) decay is related to many fundamental concepts in nuclear and particle physics beyond the standard model. Currently there are many experiments searching for this weak process. An accurate knowledge of the nuclear matrix element for the 0 ν β β decay is essential for determining the effective neutrino mass once this process is eventually measured. Purpose: We report the first full relativistic description of the 0 ν β β decay matrix element based on a state-of-the-art nuclear structure model. Methods: We adopt the full relativistic transition operators which are derived with the charge-changing nucleonic currents composed of the vector coupling, axial-vector coupling, pseudoscalar coupling, and weak-magnetism coupling terms. The wave functions for the initial and final nuclei are determined by the multireference covariant density functional theory (MR-CDFT) based on the point-coupling functional PC-PK1. Correlations beyond the mean field are introduced by configuration mixing of both angular momentum and particle number projected quadrupole deformed mean-field wave functions. Results: The low-energy spectra and electric quadrupole transitions in 150Nd and its daughter nucleus 150Sm are well reproduced by the MR-CDFT calculations. The 0 ν β β decay matrix elements for both the 01+→01+ and 01+→02+ decays of 150Nd are evaluated. The effects of particle number projection, static and dynamic deformations, and the full relativistic structure of the transition operators on the matrix elements are studied in detail. Conclusions: The resulting 0 ν β β decay matrix element for the 01+→01+ transition is 5.60 , which gives the most optimistic prediction for the next generation of experiments searching for the 0 ν β β decay in 150Nd.

  16. Change of nuclear configurations in the neutrinoless double-β decay of 130Te →130Be and 136Xe136Ba

    NASA Astrophysics Data System (ADS)

    Entwisle, J. P.; Kay, B. P.; Tamii, A.; Adachi, S.; Aoi, N.; Clark, J. A.; Freeman, S. J.; Fujita, H.; Fujita, Y.; Furuno, T.; Hashimoto, T.; Hoffman, C. R.; Ideguchi, E.; Ito, T.; Iwamoto, C.; Kawabata, T.; Liu, B.; Miura, M.; Ong, H. J.; Schiffer, J. P.; Sharp, D. K.; Süsoy, G.; Suzuki, T.; Szwec, S. V.; Takaki, M.; Tsumura, M.; Yamamoto, T.

    2016-06-01

    The change in the configuration of valence protons between the initial and final states in the neutrinoless double-β decay of 130Te → 130Be and of 136Xe136Ba has been determined by measuring the cross sections of the (d ,3He) reaction with 101-MeV deuterons. Together with our recent determination of the relevant neutron configurations involved in the process, a quantitative comparison with the latest shell-model and interacting-boson-model calculations reveals significant discrepancies. These are the same calculations used to determine the nuclear matrix elements governing the rate of neutrinoless double-β decay in these systems.

  17. Nuclear physics insights for new-physics searches using nuclei: Neutrinoless ββ decay and dark matter direct detection

    NASA Astrophysics Data System (ADS)

    Menéndez, Javier

    2017-03-01

    Experiments using nuclei to probe new physics beyond the Standard Model, such as neutrinoless ββ decay searches testing whether neutrinos are their own antiparticle, and direct detection experiments aiming to identify the nature of dark matter, require accurate nuclear physics input for optimizing their discovery potential and for a correct interpretation of their results. This demands a detailed knowledge of the nuclear structure relevant for these processes. For instance, neutrinoless ββ decay nuclear matrix elements are very sensitive to the nuclear correlations in the initial and final nuclei, and the spin-dependent nuclear structure factors of dark matter scattering depend on the subtle distribution of the nuclear spin among all nucleons. In addition, nucleons are composite and strongly interacting, which implies that many-nucleon processes are necessary for a correct description of nuclei and their interactions. It is thus crucial that theoretical studies and experimental analyses consider β decays and dark matter interactions with a coupling to two nucleons, called two-nucleon currents.

  18. Inelastic neutron scattering cross section measurements for Xe,136134 of relevance to neutrinoless double-β decay searches

    NASA Astrophysics Data System (ADS)

    Peters, E. E.; Ross, T. J.; Liu, S. H.; McEllistrem, M. T.; Yates, S. W.

    2017-01-01

    Neutrinoless double-β decay (0 ν β β ) searches typically involve large-scale experiments for which backgrounds can be complex. One possible source of background near the 0 ν β β signature in the observed spectra is γ rays arising from inelastic neutron scattering from the materials composing or surrounding the detector. In relation to searches for the 0 ν β β of 136Xe to 136Ba, such as the EXO-200 and KamLAND-Zen projects, inelastic neutron scattering γ -ray production cross sections for 136Xe and 134Xe are of importance for characterizing such γ rays that may inhibit the unambiguous identification of this yet-to-be-observed process. These cross sections have been measured at the University of Kentucky Accelerator Laboratory at neutron energies from 2.5 to 4.5 MeV.

  19. Fundamental processes in the interacting boson model: 0{nu}{beta}{beta} decay

    SciTech Connect

    Iachello, F.; Barea, J.

    2011-05-06

    A program to calculate nuclear matrix elements for fundamental processes in the interacting boson model has been initiated. Results for the nuclear matrix elements in neutrinoless double beta decay 0{nu}{beta}{beta} are presented.

  20. Status of the MAJORANA DEMONSTRATOR experiment

    SciTech Connect

    Martin, R. D.; Abgrall, N.; Aguayo, Estanislao; Avignone, F. T.; Barabash, Alexander S.; Bertrand, F.; Boswell, M.; Brudanin, V.; Busch, Matthew; Caldwell, A. S.; Chan, Yuen-Dat; Christofferson, Cabot-Ann; Combs, Dustin C.; Detwiler, Jason A.; Doe, P. J.; Efremenko, Yuri; Egorov, Viatcheslav; Ejiri, H.; Elliott, S.; Esterline, James H.; Fast, James E.; Finnerty, P.; Fraenkle, Florian; Galindo-Uribarri, A.; Giovanetti, G. K.; Goett, J.; Green, M.; Gruszko, J.; Guiseppe, Vincente; Gusev, K.; Hallin, A. L.; Hazama, R.; Hegai, A.; Henning, R.; Hoppe, Eric W.; Howard, Stanley; Howe, M. A.; Keeter, K.; Kidd, M. F.; Kochetov, Oleg; Konovalov, S.; Kouzes, Richard T.; LaFerriere, Brian D.; Leon, Jonathan D.; Leviner, L.; Loach, J. C.; MacMullin, J.; MacMullin, S.; Mertens, S.; Mizouni, Leila; Nomachi, Masaharu; Orrell, John L.; O'Shaughnessy, Mark D.; Overman, Nicole R.; Phillips, David; Poon, Alan; Pushkin, K.; Radford, D. C.; Rielage, Keith; Robertson, R. G. H.; Romero-Romero, E.; Ronquest, M. C.; Schubert, Alexis G.; Shanks, B.; Shima, T.; Shirchenko, M.; Snavely, Kyle J.; Snyder, N.; Soin, Aleksandr; Suriano, Anne-Marie; Thompson, J.; Timkin, V.; Tornow, W.; Varner, R. L.; Vasilyev, Sergey; Vetter, Kai; Vorren, Kris R.; White, Brandon R.; Wilkerson, J. F.; Xu, W.; Yakushev, E.; Young, A.; Yu, Chang-Hong; Yumatov, Vladimir

    2014-07-08

    The MAJORANA DEMONSTRATOR neutrinoless double beta-decay experiment is currently under construction at the Sanford Underground Research Facility in South Dakota, USA. An overview and status of the experiment are given.

  1. Status of the MAJORANA DEMONSTRATOR experiment

    SciTech Connect

    Martin, R. D.; Abgrall, N.; Chan, Y-D.; Hegai, A.; Mertens, S.; Poon, A. W. P.; Vetter, K.; Aguayo, E.; Fast, J. E.; Hoppe, E. W.; Kouzes, R. T.; LaFerriere, B. D.; Orrell, J. L.; Overman, N. R.; Soin, A.; Avignone III, F. T.; Barabash, A. S.; Konovalov, S. I.; Yumatov, V.; Bertrand, F. E.; and others

    2014-06-24

    The MAJORANA DEMONSTRATOR neutrinoless double beta-decay experiment is currently under construction at the Sanford Underground Research Facility in South Dakota, USA. An overview and status of the experiment are given.

  2. The low-energy program of the MAJORANA DEMONSTRATOR

    NASA Astrophysics Data System (ADS)

    Massarczyk, Ralph; MAJORANA Collaboration

    2017-01-01

    The MAJORANA Collaboration constructed an ultra-low background, modular high-purity Ge detector array to search for neutrinoless double-beta decay in 76Ge. Located at the 4850-ft level of the Sanford Underground Research Facility, the DEMONSTRATOR detector assembly has the goal to show that it is possible to achieve background rates necessary for future ton-scale experiments. The ultra-clean assembly in combination with low-noise p-type point contact detectors allows measurements with thresholds in the keV range. The talk will give an overview of the low-energy physics and recent achievements made since the completed DEMONSTRATOR array started data taking in mid 2016. Recent results from campaign will be presented, including new limits on bosonic dark matter interaction rates. This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics, the Particle Astrophysics Program of the National Science Foundation, and the Sanford Underground Research Facility. We acknowledge the support of the U.S. Department of Energy through the LANL/LDRD Program.

  3. Experimental monitoring for the MAJORANA DEMONSTRATOR

    NASA Astrophysics Data System (ADS)

    Xu, Wenqin; MAJORANA Collaboration

    2017-01-01

    The MAJORANA DEMONSTRATOR neutrinoless double beta (0 νββ) decay experiment has instrumented two modules of high purity germanium (HPGe) detectors to search for 0 νββ decay in 76Ge. The experiment has started accumulating quality data towards its goal of demonstrating the technical feasibility and low backgrounds for a next generation Ge-based 0 νββ experiment. It is critical to extensively monitor the performance of the experimental apparatus without disturbing the blindness data-taking scheme. The experimental monitoring is composed of several stages including, for example, the live monitoring embedded in the Data-Acquisition system, onsite near-live monitoring and data production monitoring. In all stages, automatic alerting mechanisms and scheduled manual checks are implemented in a coordinated way. In this talk, we will discuss the internal management of each experimental monitoring stage and their relationships to each other. This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics, the Particle Astrophysics and Nuclear Physics Programs of the National Science Foundation, and Sanford Underground Research Facility.

  4. The MAJORANA DEMONSTRATOR for 0νββ: Current status and future plans

    DOE PAGES

    Green, M. P.; Abgrall, N.; Aguayo, E.; ...

    2015-01-01

    The Majorana Demonstrator will search for neutrinoless-double-beta decay (0νββ) in 76Ge, while establishing the feasibility of a future tonne-scale germanium-based 0νββ experiment, and performing searches for new physics beyond the Standard Model. The experiment, currently under construction at the Sanford Underground Research Facility in Lead, SD, will consist of a pair of modular high-purity germanium detector arrays housed inside of a compact copper, lead, and polyethylene shield. Through a combination of strict materials qualifications and assay, low-background design, and powerful background rejection techniques, the Demonstrator aims to achieve a background rate in the 0νββ region of interest (ROI) of nomore » more than 3 counts in the 0νββ-decay ROI per tonne of target isotope per year (cnts/(ROI-t-y)). The current status of the Demonstrator is discussed, as are plans for its completion.« less

  5. High voltage testing for the Majorana Demonstrator

    SciTech Connect

    Abgrall, N.; Arnquist, Isaac J.; Avignone, F. T.; Barabash, A.; Bertrand, F.; Bradley, A. W.; Brudanin, V.; Busch, Matthew; Buuck, M.; Byram, D.; Caldwell, A. S.; Chan, Yuen-Dat; Christofferson, C. D.; Chu, Pamela M.; Cuesta, C.; Detwiler, Jason A.; Doe, P. J.; Dunagan, C.; Efremenko, Yuri; Ejiri, H.; Elliott, S. R.; Fu, Z.; Galindo-Uribarri, A.; Giovanetti, G. K.; Goett, J.; Green, M. P.; Gruszko, J.; Guinn, I.; Guiseppe, V. E.; Henning, R.; Hoppe, Eric W.; Howard, S.; Howe, M. A.; Jasinski, B. R.; Keeter, K.; Kidd, M. F.; Konovalov, S.; Kouzes, Richard T.; Laferriere, Brian D.; Leon, Jonathan D.; Li, Alexander D.; MacMullin, J.; Martin, R. D.; Massarcyk, R.; Meijer, S. J.; Mertens, S.; Orrell, John L.; O'Shaughnessy, C.; Poon, Alan W.; Radford, D. C.; Rager, J.; Rielage, Keith; Robertson, R. G. H.; Romero Romo, M.; Shanks, B.; Shirchenko, M.; Snyder, N.; Suriano, Anne-Marie E.; Tedeschi, D.; Thompson, Andrew; Ton, K. T.; Trimble, J. E.; Varner, R. L.; Vasilyev, Sergey; Vetter, Kai; Vorren, Kris R.; White, Brandon R.; Wilkerson, J. F.; Wiseman, C.; Xu, W.; Yakushev, E.; Yu, Chang-Hong; Yumatov, V.

    2016-07-01

    The Majorana Collaboration is constructing theMajorana Demonstrator, an ultra-low background, 44-kg modular high-purity Ge (HPGe) detector array to search for neutrinoless double-beta decay in 76Ge. The phenomenon of surface micro-discharge induced by high-voltage has been studied in the context of theMajorana Demonstrator. This effect can damage the front-end electronics or mimic detector signals. To ensure the correct performance, every high-voltage cable and feedthrough must be capable of supplying HPGe detector operating voltages as high as 5 kV without exhibiting discharge. R&D measurements were carried out to understand the testing system and determine the optimum design configuration of the high-voltage path, including different improvements of the cable layout and feedthrough flange model selection. Every cable and feedthrough to be used at the Majorana Demonstrator was characterized and the micro-discharge effects during theMajorana Demonstrator commissioning phase were studied. A stable configuration has been achieved, and the cables and connectors can supply HPGe detector operating voltages without exhibiting discharge.

  6. High voltage testing for the MAJORANA DEMONSTRATOR

    NASA Astrophysics Data System (ADS)

    Abgrall, N.; Arnquist, I. J.; Avignone, F. T.; Barabash, A. S.; Bertrand, F. E.; Bradley, A. W.; Brudanin, V.; Busch, M.; Buuck, M.; Byram, D.; Caldwell, A. S.; Chan, Y.-D.; Christofferson, C. D.; Chu, P.-H.; Cuesta, C.; Detwiler, J. A.; Doe, P. J.; Dunagan, C.; Efremenko, Yu.; Ejiri, H.; Elliott, S. R.; Fu, Z.; Galindo-Uribarri, A.; Giovanetti, G. K.; Goett, J.; Green, M. P.; Gruszko, J.; Guinn, I. S.; Guiseppe, V. E.; Henning, R.; Hoppe, E. W.; Howard, S.; Howe, M. A.; Jasinski, B. R.; Keeter, K. J.; Kidd, M. F.; Konovalov, S. I.; Kouzes, R. T.; LaFerriere, B. D.; Leon, J.; Li, A.; MacMullin, J.; Martin, R. D.; Massarczyk, R.; Meijer, S. J.; Mertens, S.; Orrell, J. L.; O'Shaughnessy, C.; Poon, A. W. P.; Radford, D. C.; Rager, J.; Rielage, K.; Robertson, R. G. H.; Romero-Romero, E.; Shanks, B.; Shirchenko, M.; Snyder, N.; Suriano, A. M.; Tedeschi, D.; Thompson, A.; Ton, K. T.; Trimble, J. E.; Varner, R. L.; Vasilyev, S.; Vetter, K.; Vorren, K.; White, B. R.; Wilkerson, J. F.; Wiseman, C.; Xu, W.; Yakushev, E.; Yu, C.-H.; Yumatov, V.

    2016-07-01

    The MAJORANA Collaboration is constructing the MAJORANA DEMONSTRATOR, an ultra-low background, 44-kg modular high-purity Ge (HPGe) detector array to search for neutrinoless double-beta decay in 76Ge. The phenomenon of surface micro-discharge induced by high-voltage has been studied in the context of the MAJORANA DEMONSTRATOR. This effect can damage the front-end electronics or mimic detector signals. To ensure the correct performance, every high-voltage cable and feedthrough must be capable of supplying HPGe detector operating voltages as high as 5 kV without exhibiting discharge. R&D measurements were carried out to understand the testing system and determine the optimum design configuration of the high-voltage path, including different improvements of the cable layout and feedthrough flange model selection. Every cable and feedthrough to be used at the MAJORANA DEMONSTRATOR was characterized and the micro-discharge effects during the MAJORANA DEMONSTRATOR commissioning phase were studied. A stable configuration has been achieved, and the cables and connectors can supply HPGe detector operating voltages without exhibiting discharge.

  7. Cryogenic readout techniques for germanium detectors

    SciTech Connect

    Benato, G.; Cattadori, C.; Di Vacri, A.; Ferri, E.

    2015-07-01

    High Purity Germanium detectors are used in many applications, from nuclear and astro-particle physics, to homeland security or environment protection. Although quite standard configurations are often used, with cryostats, charge sensitive amplifiers and analog or digital acquisition systems all commercially available, it might be the case that a few specific applications, e.g. satellites, portable devices, cryogenic physics experiments, etc. also require the development of a few additional or complementary techniques. An interesting case is for sure GERDA, the Germanium Detector Array experiment, searching for neutrino-less double beta decay of {sup 76}Ge at the Gran Sasso National Laboratory of INFN - Italy. In GERDA the entire detector array, composed of semi-coaxial and BEGe naked crystals, is operated suspended inside a cryostat filled with liquid argon, that acts not only as cooling medium and but also as an active shield, thanks to its scintillation properties. These peculiar circumstances, together with the additional requirement of a very low radioactive background from all the materials adjacent to the detectors, clearly introduce significant constraints on the design of the Ge front-end readout electronics. All the Ge readout solutions developed within the framework of the GERDA collaboration, for both Phase I and Phase II, will be briefly reviewed, with their relative strength and weakness compared together and with respect to ideal Ge readout. Finally, the digital processing techniques developed by the GERDA collaboration for energy estimation of Ge detector signals will be recalled. (authors)

  8. GERDA phase II detectors: Behind the production and characterisation at low background conditions

    SciTech Connect

    Maneschg, Werner; Collaboration: GERDA Collaboration; and others

    2013-08-08

    The low background GERmanium Detector Array (GERDA) at Laboratori Nazionali del Gran Sasso (LNGS) is designed to search for the rare neutrinoless double beta decay (0νββ) in {sup 76}Ge. Bare germanium diodes are operated in liquid argon which is used as coolant, as passive and soon active as well shield against external radiation. Currently, Phase I of the experiment is running using ∼15 kg of co-axial High Purity Germanium diodes. In order to increase the sensitivity of the experiment 30 Broad Energy Germanium (BEGe) diodes will be added within 2013. This presentation reviews the production chain of the new BEGe detectors from isotopic enrichment to diode production and testing. As demonstrated all steps were carefully planned in order to minimize the exposure of the enriched germanium to cosmic radiation. Following this premise, acceptance and characterisation measurement of the newly produced diodes have been performed within the HEROICA project in the Belgian underground laboratory HADES close to the diode manufacturer. The test program and the results from a subset of the recently terminated GERDA Phase II BEGe survey will be presented.

  9. Design and Operation of Cryogenic Distillation Research Column for Ultra-Low Background Experiments

    NASA Astrophysics Data System (ADS)

    Chiller, Christopher; Alanson Chiller, Angela; Jasinski, Benjamin; Snyder, Nathan; Mei, Dongming

    2013-04-01

    Motivated by isotopically enriched germanium (76Ge and 73Ge) for monocrystalline crystal growth for neutrinoless double-beta decay and dark matter experiments, a cryogenic distillation research column was developed. Without market availability of distillation columns in the temperature range of interest with capabilities necessary for our purposes, we designed, fabricated, tested, refined and operated a two-meter research column for purifying and separating gases in the temperature range from 100-200K. Due to interest in defining stratification, purity and throughput optimization, capillary lines were integrated at four equidistant points along the length of the column such that real-time residual gas analysis could guide the investigation. Interior gas column temperatures were monitored and controlled within 0.1oK accuracy at the top and bottom. Pressures were monitored at the top of the column to four significant figures. Subsequent impurities were measured at partial pressures below 2E-8torr. We report the performance of the column in this paper.

  10. ICP MS selection of radiopure materials for the GERDA experiment

    SciTech Connect

    Di Vacri, M. L.; Nisi, S.; Cattadori, C.; Janicsko, J.; Lubashevskiy, A.; Smolnikov, A.; Walter, M.

    2015-08-17

    The GERDA (GERmanium Detector Array) experiment, located in the Gran Sasso Underground Laboratory (LNGS, Italy) aims to search for neutrinoless double beta (0νββ) decay of the {sup 76}Ge isotope. Both an ultra-low radioactivity background environment and active techniques to abate the residual background are required to reach the background index (of 10{sup −3} counts/keV kg y) at the Q{sub ββ}. In order to veto and suppress those events that partially deposit energy in Ge detectors, the readout of liquid argon (LAr) scintillation light (SL) has been implemented for the second GERDA experimental Phase. A double veto system has been designed and constructed using highly radiopure materials (scintillating fibers, wavelength shifters, polymeric foils, reflective foils). This work describes the study of lead, thorium and uranium ultra-trace content, performed at the LNGS Chemistry Laboratory by High Resolution Mass Spectrometry (HR ICP MS), for the selection of all materials involved in the construction of the veto system.

  11. Background Model for the Majorana Demonstrator

    SciTech Connect

    Cuesta, C.; Abgrall, N.; Aguayo, Estanislao; Avignone, Frank T.; Barabash, Alexander S.; Bertrand, F.; Boswell, M.; Brudanin, V.; Busch, Matthew; Byram, D.; Caldwell, A. S.; Chan, Yuen-Dat; Christofferson, Cabot-Ann; Combs, Dustin C.; Detwiler, Jason A.; Doe, Peter J.; Efremenko, Yuri; Egorov, Viatcheslav; Ejiri, H.; Elliott, S. R.; Fast, James E.; Finnerty, P.; Fraenkle, Florian; Galindo-Uribarri, A.; Giovanetti, G. K.; Goett, J.; Green, M. P.; Gruszko, J.; Guiseppe, Vincente; Gusev, K.; Hallin, A. L.; Hazama, R.; Hegai, A.; Henning, Reyco; Hoppe, Eric W.; Howard, Stanley; Howe, M. A.; Keeter, K.; Kidd, M. F.; Kochetov, Oleg; Konovalov, S.; Kouzes, Richard T.; Laferriere, Brian D.; Leon, Jonathan D.; Leviner, L.; Loach, J. C.; MacMullin, J.; MacMullin, S.; Martin, R. D.; Meijer, S. J.; Mertens, S.; Nomachi, Masaharu; Orrell, John L.; O'Shaughnessy, C.; Overman, Nicole R.; Phillips, D.; Poon, Alan; Pushkin, K.; Radford, D. C.; Rager, J.; Rielage, Keith; Robertson, R. G. H.; Romero-Romero, E.; Ronquest, M. C.; Schubert, Alexis G.; Shanks, B.; Shima, T.; Shirchenko, M.; Snavely, Kyle J.; Snyder, N.; Suriano, Anne-Marie; Thompson, J.; Timkin, V.; Tornow, Werner; Trimble, J. E.; Varner, R. L.; Vasilyev, Sergey; Vetter, Kai; Vorren, Kris R.; White, Brandon R.; Wilkerson, J. F.; Wiseman, C.; Xu, W.; Yakushev, E.; Young, A.; Yu, Chang-Hong; Yumatov, Vladimir

    2015-06-01

    The Majorana Collaboration is constructing a prototype system containing 40 kg of HPGe detectors to demonstrate the feasibility and potential of a future tonne-scale experiment to search for neutrinoless double-beta (0v BB) decay in 76Ge. In view of the requirement that the next generation of tonne-scale Ge-based 0vBB-decay experiment be capable of probing the neutrino mass scale in the inverted-hierarchy region, a major goal of theMajorana 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, for example using powerful pulse shape analysis techniques profiting from the p-type point contact HPGe detectors technology. The effectiveness of these methods is assessed using Geant4 simulations of the different background components whose purity levels are constrained from radioassay measurements.

  12. Cryogenic Supply for the Gerda Experiment

    NASA Astrophysics Data System (ADS)

    Haberstroh, Ch.

    2008-03-01

    In the GERDA experiment (GERmanium Detector Array for the search of neutrinoless double beta decay of 76Ge) germanium diodes are suspended in a superinsulated cryostat filled with 70 m3 of liquid argon. The cold medium is required since the diodes have to be operated at low temperatures, and furthermore for shielding against background radiation. For the same reason the whole experiment will be placed in the underground laboratories in the Gran Sasso mountains, Italy. In order to avoid any detrimental perturbation inside the dewar vessel, the liquid-argon (LAr) inventory in the main tank will be kept in a subcooled state at a working pressure of 0.12 MPa absolute at the surface. At the TU Dresden an appropriate cryogenic arrangement was designed to match these requirements. Liquid nitrogen (LN2) is used as a cooling fluid. Special care was taken to cope with the narrow temperature span between the LAr boiling temperature and triple point. In the proposed solution a subcooler located close to the cryostat neck provides a stable LAr convection inside the main tank. The working pressure is adjusted with a controlled, slightly elevated temperature level at the liquid-vapor interface.

  13. 0{nu}{beta}{beta}-decay nuclear matrix elements with self-consistent short-range correlations

    SciTech Connect

    Simkovic, Fedor; Faessler, Amand; Muether, Herbert; Rodin, Vadim; Stauf, Markus

    2009-05-15

    A self-consistent calculation of nuclear matrix elements of the neutrinoless double-beta decays (0{nu}{beta}{beta}) of {sup 76}Ge, {sup 82}Se, {sup 96}Zr, {sup 100}Mo, {sup 116}Cd, {sup 128}Te, {sup 130}Te, and {sup 136}Xe is presented in the framework of the renormalized quasiparticle random phase approximation (RQRPA) and the standard QRPA. The pairing and residual interactions as well as the two-nucleon short-range correlations are for the first time derived from the same modern realistic nucleon-nucleon potentials, namely, from the charge-dependent Bonn potential (CD-Bonn) and the Argonne V18 potential. In a comparison with the traditional approach of using the Miller-Spencer Jastrow correlations, matrix elements for the 0{nu}{beta}{beta} decay are obtained that are larger in magnitude. We analyze the differences among various two-nucleon correlations including those of the unitary correlation operator method (UCOM) and quantify the uncertainties in the calculated 0{nu}{beta}{beta}-decay matrix elements.

  14. Search for Pauli exclusion principle violating atomic transitions and electron decay with a p-type point contact germanium detector

    DOE PAGES

    Abgrall, N.; Arnquist, I. J.; Avignone, F. T.; ...

    2016-11-11

    Here, a search for Pauli-exclusion-principle-violating Kα electron transitions was performed using 89.5 kg-d of data collected with a p-type point contact high-purity germanium detector operated at the Kimballton Underground Research Facility. A lower limit on the transition lifetime of 5.8×1030 s at 90% C.L. was set by looking for a peak at 10.6 keV resulting from the X-ray and Auger electrons present following the transition. A similar analysis was done to look for the decay of atomic K-shell electrons into neutrinos, resulting in a lower limit of 6.8×1030 s at 90% C.L. Finally, it is estimated that the Majorana Demonstrator,more » a 44 kg array of p-type point contact detectors that will search for the neutrinoless double-beta decay of 76Ge, could improve upon these exclusion limits by an order of magnitude after three years of operation.« less

  15. GERDA phase II detectors: Behind the production and characterisation at low background conditions

    NASA Astrophysics Data System (ADS)

    Maneschg, Werner; Gerda Collaboration

    2013-08-01

    The low background GERmanium Detector Array (GERDA) at Laboratori Nazionali del Gran Sasso (LNGS) is designed to search for the rare neutrinoless double beta decay (0νββ) in 76Ge. Bare germanium diodes are operated in liquid argon which is used as coolant, as passive and soon active as well shield against external radiation. Currently, Phase I of the experiment is running using ˜15 kg of co-axial High Purity Germanium diodes. In order to increase the sensitivity of the experiment 30 Broad Energy Germanium (BEGe) diodes will be added within 2013. This presentation reviews the production chain of the new BEGe detectors from isotopic enrichment to diode production and testing. As demonstrated all steps were carefully planned in order to minimize the exposure of the enriched germanium to cosmic radiation. Following this premise, acceptance and characterisation measurement of the newly produced diodes have been performed within the HEROICA project in the Belgian underground laboratory HADES close to the diode manufacturer. The test program and the results from a subset of the recently terminated GERDA Phase II BEGe survey will be presented.

  16. Germanium Detector Crystal Axis Orientation for the MAJORANA Demonstrator

    NASA Astrophysics Data System (ADS)

    Letourneau, Hannah

    2013-10-01

    The MAJORANA Demonstrator, currently being constructed at Sanford Underground Research Facility in Lead, South Dakota, is an array of germanium detectors which will be used to search for neutrinoless double beta decay, which would demonstrate that neutrinos have a Majorana mass term and lepton number is not conserved. An important characteristic of semiconductor detectors is the crystal axis orientation, because the propagation of electromagnetic signals is attenuated by the location of the interaction relative to the axis of the crystal. Conventionally, a goniometer is used to position a collimated low energy gamma source in many small increments around the detector to measure the rise time at each position. However, due to physical constraints from the casing of the Demonstrator, a different method must be developed. At the University of Washington this summer, I worked with a 76 Ge point-contact detector. I found the crystal axis orientation first with Americium 241, a lower energy gamma source. Then, I used a higher energy source, Thorium 232, in conjunction with the only a few angular reference points to also calculate rise time. Also, I wrote code to process the data. The success of this method will be evaluated and discussed. NSF

  17. Majo-ra-na: An Ultra-Low Background Enriched-Germanium Detector Array for Fundamental Physics Measurements

    NASA Astrophysics Data System (ADS)

    Gehman, Victor

    2010-02-01

    The Majo-ra-na collaboration will search for neutrinoless double-beta decay (0νββ) by fielding an array of high-purity germanium (HPGe) detectors in ultra-clean electroformed-copper cryostats deep underground. Recent advances in HPGe detector technology, in particular P-type Point-Contact (PPC) detectors, present exciting new techniques for identifying and reducing backgrounds to the 0νββ signal. This should result in greatly improved sensitivity over previous generation experiments. The very low energy threshold attainable with PPC detectors also provides for a broader physics program including searches for dark matter and axions. The Majo-ra-na De-mon-strat-or is an R&D program that will field three ˜20 kg modules of PPC detectors at Sanford Underground Laboratory. Half of the detectors will be enriched to 86% in ^76Ge. Here, we will cover the motivation, design, recent progress and current status of this effort, with special attention to its physics reach. )

  18. The MOON project and DBD matrix elements

    NASA Astrophysics Data System (ADS)

    Ejiri, H.

    2009-06-01

    This is a brief report on experimental studies of double beta decays (DBD) in Japan, the MOON project for spectroscopic studies of neutrino-less DBD (0vββ) and on experimental studies of DBD nuclear matrix elements. Experimental DBD studies in Japan were made by geochemical methods on 130Te, 128Te and 96Zr and by a series of ELEGANT(EL) counting methods, EL III on 76Ge, EL IV, V on 100Mo, 116Cd, and EL VI on 48Ca. Future counter experiments are MOON, CANDLES, XMASS and DCBA. The MOON project, which is based on EL V, aims at studies of the Majorana nature of the neutrino (v) and the v-mass spectrum by spectroscopic 0vββ experiments with the v-mass sensitivity of < mmv > = 100-30 meV. The MOON detector is a super ensemble of multi-layer modules, each being composed by PL scintillator plates and position-sensitive detector planes. DBD nuclear matrix elements have been studied experimentally by using charge exchange reactions. The 2-neutrino DBD matrix elements are expressed by successive single-β matrix elements through low-lying intermediate states.

  19. The MAJORANA Demonstrator Low-Energy Rare Event Search

    NASA Astrophysics Data System (ADS)

    Wiseman, Clinton; Majorana Collaboration

    2016-09-01

    The extremely low backgrounds of the MAJORANA DEMONSTRATOR neutrinoless double beta decay experiment, combined with the excellent energy resolution of its high-purity germanium (HPGe) detectors, provide an opportunity for a dark matter search at low energy (<100 keV). The DEMONSTRATOR is in the final stages of construction at the 4850-ft. level of the Sanford Underground Research Facility in Lead, SD. The first detector module, consisting of 16.8 kg of HPGe enriched to 88% 76Ge and 5.7 kg of natural HPGe, took 100.6 live days of commissioning data before going blind on April 14th, 2016, and the second module is nearing completion at the time of this writing. The enriched detectors have particularly low levels of cosmogenic activation from their specialized manufacturing process. These ultra-low background designs are suited to rare event searches at low energies, including light WIMPs (<10 GeV/c2) and solar axions. In this talk an update of the MAJORANA low-energy research program will be presented. This material is based upon work supported by the U.S. DOE, Office of Science, Office of Nuclear Physics, the Particle Astrophysics and Nuclear Physics Programs of the National Science Foundation, and the Sanford Underground Research Facility.

  20. Low background signal readout electronics for the MAJORANA DEMONSTRATOR

    SciTech Connect

    Guinn, I.; Buuck, M.; Cuesta, C.; Detwiler, J. A.; Gruszko, J.; Leon, J.; Robertson, R. G. H.; Abgrall, N.; Bradley, A. W.; Chan, Y-D.; Mertens, S.; Poon, A. W. P.; Arnquist, I. J.; Hoppe, E. W.; Kouzes, R. T.; LaFerriere, B. D.; Orrell, J. L.; Avignone, F. T.; Baldenegro-Barrera, C. X.; Bertrand, F. E.; and others

    2015-08-17

    The MAJORANA Collaboration will seek neutrinoless double beta decay (0νββ) in {sup 76}Ge using isotopically enriched p-type point contact (PPC) high purity Germanium (HPGe) detectors. A tonne-scale array of HPGe detectors would require background levels below 1 count/ROI-tonne-year in the 4 keV region of interest (ROI) around the 2039 keV Q-value of the decay. In order to demonstrate the feasibility of such an experiment, the MAJORANA DEMONSTRATOR, a 40 kg HPGe detector array, is being constructed with a background goal of < 3 count/ROI-tonne-year, which is expected to scale down to < 1 count/ROI-tonne-year for a tonne-scale experiment. The signal readout electronics, which must be placed in close proximity to the detectors, present a challenge toward reaching this background goal. This talk will discuss the materials and design used to construct signal readout electronics with low enough backgrounds for the MAJORANA DEMONSTRATOR.

  1. Extracting information on the 0νββ decays from the 2νββ decays

    NASA Astrophysics Data System (ADS)

    Civitarese, O.; Suhonen, J.

    2005-11-01

    We have analyzed the relation between the two-neutrino (2νββ) and neutrinoless (0νββ) double beta decays of 76Ge, 82Se, 100Mo, and 116Cd. The relevant nuclear matrix elements have been calculated by using the proton-neutron quasiparticle random-phase approximation (pn-QRPA) with realistic two-body interactions. The dependence of the calculated matrix elements on the strength g of the particle-particle part of the proton-neutron two-body interaction is investigated. Recently a procedure was proposed where data on 2νββ-decay half-lives could be used to derive appropriate values of g for calculating the 0νββ-decay matrix elements. Following this procedure, we have determined the allowed values of g by including experimental errors of the measured 2νββ-decay half-lives and the uncertainties in the axial-vector coupling constant g. This set of g values is used to predict single-beta and 0νββ observables. Careful study of these observables points to serious shortcomings in the adopted procedure.

  2. High voltage testing for the Majorana Demonstrator

    DOE PAGES

    Abgrall, N.; Arnquist, I. J.; Avignone, III, F. T.; ...

    2016-04-04

    The Majorana Collaboration is constructing the Majorana Demonstrator, an ultra-low background, 44-kg modular high-purity Ge (HPGe) detector array to search for neutrinoless double-beta decay in 76Ge. The phenomenon of surface micro-discharge induced by high-voltage has been studied in the context of the Majorana Demonstrator. This effect can damage the front-end electronics or mimic detector signals. To ensure the correct performance, every high-voltage cable and feedthrough must be capable of supplying HPGe detector operating voltages as high as 5 kV without exhibiting discharge. R&D measurements were carried out to understand the testing system and determine the optimum design configuration of themore » high-voltage path, including different improvements of the cable layout and feedthrough flange model selection. Every cable and feedthrough to be used at the Majorana Demonstrator was characterized and the micro-discharge effects during the Majorana Demonstrator commissioning phase were studied. Furthermore, a stable configuration has been achieved, and the cables and connectors can supply HPGe detector operating voltages without exhibiting discharge.« less

  3. Background rejection of n+ surface events in GERDA Phase II

    NASA Astrophysics Data System (ADS)

    Lehnert, Björn

    2016-05-01

    The GERDA experiment searches for neutrinoless double beta (0vββ) decay in 76Ge using an array of high purity germanium (HPGe) detectors immersed in liquid argon (LAr). Phase II of the experiment uses 30 new broad energy germanium (BEGe) detectors with superior pulse shape discrimination capabilities compared to the previously used semi-coaxial detector design. By far the largest background component for BEGe detectors in GERDA are n+-surface events from 42K β decays which are intrinsic in LAr. The β particles with up to 3.5 MeV can traverse the 0.5 to 0.9 mm thick electrode and deposit energy within the region of interest for the 0vββ decay. However, those events have particular pulse shape features allowing for a strong discrimination. The understanding and simulation of this background, showing a reduction by up to a factor 145 with pulse shape discrimination alone, is presented in this work.

  4. Search for Pauli exclusion principle violating atomic transitions and electron decay with a p-type point contact germanium detector

    DOE PAGES

    Abgrall, N.; Arnquist, I. J.; Avignone, F. T.; ...

    2016-11-11

    Here, a search for Pauli-exclusion-principle-violating Kα electron transitions was performed using 89.5 kg-d of data collected with a p-type point contact high-purity germanium detector operated at the Kimballton Underground Research Facility. A lower limit on the transition lifetime of 5.8 × 1030 s at 90% C.L. was set by looking for a peak at 10.6 keV resulting from the X-ray and Auger electrons present following the transition. A similar analysis was done to look for the decay of atomic K-shell electrons into neutrinos, resulting in a lower limit of 6.8 × 1030 s at 90% C.L. It is estimated thatmore » the Majorana Demonstrator, a 44 kg array of p-type point contact detectors that will search for the neutrinoless double-beta decay of 76Ge, could improve upon these exclusion limits by an order of magnitude after three years of operation.« less

  5. Updated constraints on the light-neutrino exchange mechanisms of the 0νββ-decay

    SciTech Connect

    Štefánik, Dušan; Dvornický, Rastislav; Šimkovic, Fedor

    2015-10-28

    The neutrinoless double-beta (0νββ) decay associated with light neutrino exchange mechanisms, which are due to both left-handed V-A and right-handed V+A leptonic and hadronic currents, is discussed by using the recent progress achieved by the GERDA, EXO and KamlandZen experiments. The upper limits for effective neutrino mass m{sub ββ} and the parameters 〈λ〉 and 〈η〉 characterizing the right handed current mechanisms are deduced from the data on the 0νββ-decay of {sup 76}Ge and {sup 136}Xe using nuclear matrix elements calculated within the nuclear shell model and quasiparticle random phase approximation and phase-space factors calculated with exact Dirac wave functions with finite nuclear size and electron screening. The careful analysis of upper constraints on effective lepton number violating parameters assumes a competition of the above mechanisms and arbitrary values of involved CP violating phases.

  6. Discovering the Majorana neutrino: The next generation of experiments

    SciTech Connect

    Winslow, L. A.

    2015-07-15

    The discovery of a Majorana neutrino would be revolutionary with far-reaching consequences in both particle physics and cosmology. The only feasible experiments to determine the Majorana nature of the neutrino are searches for neutrinoless double-beta decay. The next generation of double-beta decay experiments are being prepared. The general goal is to search for neutrinoless double-beta decay throughout the parameter space corresponding to the inverted hierarchy for neutrino mass. There are a several strong proposals for how to achieve this goal. The status of these efforts is reviewed.

  7. Double Beta Decay of Tellurium-130: Current Status

    NASA Technical Reports Server (NTRS)

    Meshik, A. P.; Hohenberg, C. M.; Pravdivtseva, O. V.; Bernatowicz, T. J.

    2002-01-01

    Geochemically measured values of Te-130 half-life form two distinct clusters. Two different experiments were performed to check two proposed explanations: Xe loss and Xe inheritance. Neither is observed. Additional information is contained in the original extended abstract.

  8. On Double-Beta Decay Half-Life Time Systematics

    SciTech Connect

    Pritychenko, B.

    2010-04-14

    Recommended 2{beta}(2{nu}) half-life values and their systematics were analyzed in the framework of a simple empirical approach. T{sub 1/2}{sup 2{nu}} {approx} 1/E{sup 8} trend has been observed for {sup 128,130}Te recommended values. This trend was used to predict T{sub 1/2}{sup 2{nu}} for all isotopes of interest. Current results were compared with other theoretical and experimental works.

  9. Germanium-76 Sample Analysis

    SciTech Connect

    Kouzes, Richard T.; Engelhard, Mark H.; Zhu, Zihua

    2011-04-01

    The MAJORANA DEMONSTRATOR is a large array of ultra-low background high-purity germanium detectors, enriched in 76Ge, designed to search for zero-neutrino double-beta decay (0νββ). The DEMONSTRATOR will utilize 76Ge from Russia, and the first one gram sample was received from the supplier for analysis on April 24, 2011. The Environmental Molecular Sciences facility, a DOE user facility at PNNL, was used to make the required isotopic and chemical purity measurements that are essential to the quality assurance for the MAJORANA DEMONSTRATOR. The results of this first analysis are reported here.

  10. Production of the neutron-induced isotope, 73Ga, at the Davis Campus of the Sanford Underground Research Facility with the MAJORANA DEMONSTRATOR

    NASA Astrophysics Data System (ADS)

    Chu, Pinghan; Majorana Demonstrator Collaboration

    2016-09-01

    We report a study of the production of the neutron-induced isotope, 73Ga, in the MAJORANA DEMONSTRATOR array at the underground Davis Campus of the Sanford Underground Research Facility 4850 ft level. This isotope has a half-life time of 4.86 hours and can be generated through interactions between fast neutrons and germanium isotopes. Using its unique decay signature, we have identified three candidate events of 73Ga in the commissioning data of MAJORANA DEMONSTRATOR. Based on these three events, we estimate the corresponding neutron energy spectrum and the radioactive background generated by neutron-induced isotopes. The background from neutron-induced isotopes has been also calculated in the Region of Interest for 76Ge neutrinoless double beta decays. This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics, the Particle Astrophysics Program of the National Science Foundation, and the Sanford Underground Research Facility. We acknowledge the support of the U.S. Department of Energy through the LANL/LDRD Program. U.S. Department of Energy, Office of Science, Office of Nuclear Physics under Award Numbers DE-AC02-05CH11231, DE-AC52-06NA25396, DE-FG02-97ER41041, DE-FG02-97ER41033, DE-FG02-97ER41042, DE-SC0012612, DE-FG02-10ER41715, DE-SC0010254, and DE-FG02-97ER4102.

  11. Neutral current reaction cross sections for the stable 100 Mo isotope

    NASA Astrophysics Data System (ADS)

    Balasi, K. G.; Kosmas, T. S.; Divari, P. C.; Ejiri, H.

    2010-01-01

    Motivated by the ongoing MOON neutrino experiment at Japan aiming to search for double beta and neutrinoless double beta decay events, we investigate inelastic neutrino scattering cross sections for the stable 100Mo isotope by performing state-by-state calculations. The required many body nuclear wave functions are constructed within the context of the quasi-particle random phase approximation (QRPA) tested in the reproducibility of the low-lying spectrum of the 100Mo isotope.

  12. Recent searches for double-electron capture of nuclei to excited states

    SciTech Connect

    Povinec, P. P.; Frekers, D.; Šimkovic, F.

    2015-10-28

    Double electron capture has been of interest of many theoretical and experimental works as a possible extension of double beta-decay investigations. The neutrinoless double-electron capture, similarly as the neutrinoless double beta-decay may help to clarify if neutrinos are Majorana or Dirac particles. Results obtained in several double electron capture experiments are reviewed and new experiments to be carried out in deep underground laboratories using enriched sources and multidimensional HPGe-HPGe gamma-ray spectrometry with a few years of counting time are proposed, which should be able to improve half-lives limits by at least an order of magnitude.

  13. Results from the CUORE-0 experiment

    NASA Astrophysics Data System (ADS)

    Canonica, L.; Alduino, C.; Alfonso, K.; Artusa, D. R.; Avignone, F. T., III; Azzolini, O.; Banks, T. I.; Bari, G.; Beeman, J. W.; Bellini, F.; Bersani, A.; Biassoni, M.; Brofferio, C.; Bucci, C.; Caminata, A.; Cao, X. G.; Capelli, S.; Cappelli, L.; Carbone, L.; Cardani, L.; Carniti, P.; Casali, N.; Cassina, L.; Chiesa, D.; Chott, N.; Clemenza, M.; Copello, S.; Cosmelli, C.; Cremonesi, O.; Creswick, R. J.; Cushman, J. S.; Dafinei, I.; Dally, A.; Davis, C. J.; Dell'Oro, S.; Deninno, M. M.; Di Domizio, S.; Di Vacri, M. L.; Drobizhev, A.; Fang, D. Q.; Faverzani, M.; Fernandes, G.; Ferri, E.; Ferroni, F.; Fiorini, E.; Fujikawa, B. K.; Giachero, A.; Gironi, L.; Giuliani, A.; Gladstone, L.; Gorla, P.; Gotti, C.; Gutierrez, T. D.; Haller, E. E.; Han, K.; Hansen, E.; Heeger, K. M.; Hennings-Yeomans, R.; Hickerson, K. P.; Huang, H. Z.; Kadel, R.; Keppel, G.; Kolomensky, G. Yu; Lim, K. E.; Liu, X.; Ma, Y. G.; Maino, M.; Marini, L.; Martinez, M.; Maruyama, R. H.; Mei, Y.; Moggi, N.; Morganti, S.; Mosteiro, P. J.; Nones, C.; Norman, E. B.; Nucciotti, A.; O'Donnell, T.; Orio, F.; Ouellet, J. L.; Pagliarone, C. E.; Pallavicini, M.; Palmieri, V.; Pattavina, L.; Pavan, M.; Pessina, G.; Pettinacci, V.; Piperno, G.; Pirro, S.; Pozzi, S.; Previtali, E.; Rosenfeld, C.; Rusconi, C.; Sala, E.; Sangiorgio, S.; Santone, D.; Scielzo, N. D.; Singh, V.; Sisti, M.; Smith, A. R.; Taffarello, L.; Tenconi, M.; Terranova, F.; Tomei, C.; Trentalange, S.; Ventura, G.; Vignati, M.; Wagaarachchi, S. L.; Wang, B. S.; Wang, H. W.; Wilson, J.; Winslow, L. A.; Wise, T.; Zanotti, L.; Zhang, G. Q.; Zhu, B. X.; Zimmermann, S.; Zucchelli, S.

    2016-05-01

    The CUORE-0 experiment searched for neutrinoless double beta decay in 130Te using an array of 52 tellurium dioxide crystals, operated as bolometers at a temperature of 10 mK. It took data in the Gran Sasso National Laboratory (Italy) since March 2013 to March 2015. We present the results of a search for neutrinoless double beta decay in 9.8 kg-years 130Te exposure that allowed us to set the most stringent limit to date on this half-life. The performance of the detector in terms of background and energy resolution is also reported.

  14. The Gotthard and MUNU TPCs: From the past to the future?

    NASA Astrophysics Data System (ADS)

    Vuilleumier, Jean-Luc

    2009-07-01

    The performance of two similar gas TPCs used in past low energy particle physics experiments are briefly described. The first was installed in the Gotthard underground laboratory to search for the neutrinoless double beta decay of 136Xe. The second, MUNU, was operated near the Bugey nuclear reactor to study bar vee- → bar vee- scattering. The advantages of the design are presented, along with the limitations. Ideas to improve the performance, for future experiments in low energy, low rate, particle physics are presented. The emphasis is put on the search for the neutrinoless double beta decay of 136Xe.

  15. Inelastic neutron scattering cross sections for Ge76 relevant to background in neutrinoless double- β decay experiments

    SciTech Connect

    Crider, B. P.; Peters, E. E.; Allmond, J. M.; McEllistrem, M. T.; Prados-Estévez, F. M.; Ross, T. J.; Vanhoy, J. R.; Yates, S. W.

    2015-09-11

    The experimental signature in searches for the neutrinoless double- decay of 76Ge is a peak near 2039 keV in the spectrum. Given the low probability of the process, it is important that the background in this region be well understood. Moreover, inelastic scattering reactions with neutrons from muon-induced interactions and ( ,n) reactions in the surrounding materials or in the detector can provide contributions to the background. We also measured the production cross sections for rays from the 76Ge(n,n ) reaction in the 2039-keV region at incident neutron energies up to 4.9 MeV. In addition to determining that the cross sections of a previously known 2040.7-keV ray from the 3952-keV level in 76 Ge are rather small, we find that a larger contribution arises from a 2037.5-keV ray which is attributed to a newly identified level at 3147 keV in 76Ge. Finally, a third contribution is also possible from another new level at 3577 keV. These results indicate that the 2039-keV region in 76Ge neutrinoless double- decay searches is more complex than was previously thought.

  16. Structure of A Equals 76 Nuclei and Fast-Timing Studies of the Rare-Earth Region

    NASA Astrophysics Data System (ADS)

    Cooper, Nathan Michael

    produce useful results. Such cases include estimation of total -gamma-decay widths of neutron resonances and -gamma-ray spectra following nuclear reactions. Of particular interest in modern research are so-called pygmy resonances which may be due, for example, to a neutron skin resonance or other exotic modes of excitation. Another topic of continued interest is that of double-beta decay and in particular the search for neutrinoless double-beta (0vbeta) decay. Conclusive observation of 0 vbeta decay would show that the neutrino is its own anti-particle, and evaluation of the neutrino mass could be performed if the matrix element of the decay were known. Constraining parameters of theoretical models using experimental data is of the utmost importance to these calculations. In this dissertation, the structure of A = 76 nuclei near stability, candidates for involvement in the hypothetical 0vbeta decay of 76Ge, is explored though seven experiments performed at the Darmstadt High-Intensity Photon Source, the High Intensity Gamma-Ray Source, and at the Wright Nuclear Structure Laboratory. Of particular concern is the analysis and interpretation of nuclear resonance fluorescence data on 76Se, 76Ge, and nuclei in general. Details and results of experiments performed using fast-timing electronics to study structure of low-lying states of 174W and 176Hf at WNSL are additionally presented as an appendix.

  17. Rearrangement of valence neutrons in the neutrinoless double-β decay of Xe136

    SciTech Connect

    Szwec, S. V.; Kay, B. P.; Cocolios, T. E.; Entwisle, J. P.; Freeman, S. J.; Gaffney, L. P.; Guimaraes, V.; Hammache, F.; McKee, P. P.; Parr, E.; Portail, C.; Schiffer, J. P.; de Sereville, N.; Sharp, D. K.; Smith, J. F.; Stefan, I.

    2016-11-15

    Here, a quantitative description of the change in ground-state neutron occupancies between 136Xe and 136Ba, the initial and final state in the neutrinoless double-β decay of 136Xe, has been extracted from precision measurements of the cross sections of single-neutron-adding and -removing reactions. Comparisons are made to recent theoretical calculations of the same properties using various nuclear-structure models. These are the same calculations used to determine the magnitude of the nuclear matrix elements for the process, which at present disagree with each other by factors of 2 or 3. The experimental neutron occupancies show some disagreement with the theoretical calculations.

  18. Nucleon occupancies in the A = 100 and A = 150 0ν2β decay candidate systems

    SciTech Connect

    Sharp, David K.

    2015-10-28

    We have undertaken measurements of single-nucleon and pair transfer reactions to benchmark nuclear matrix element calculations for neutrinoless double beta decay. An overview of the measured nucleon occupancies and pairing properties for the {sup 100}Mo→{sup 100}Ru system is given as well as some preliminary discussion of measurements on the {sup 150}Nd→{sup 150}Sm.

  19. THE SEARCH FOR MASSIVE NEUTRINOS - Short Contribution

    NASA Astrophysics Data System (ADS)

    Kirsten, T.

    Double beta decay (DBD) has the potential to distinguish whether neutrinos are Majorana or Dirac particles. However, neutrinoless DBD (in violation of lepton number conservation) has not yet been observed. From the respective upper limits, limits on the neutrino restmass can be deduced if the neutrino is of Majorana type.

  20. Purification of KamLAND-Zen liquid scintillator

    SciTech Connect

    Ikeda, Haruo

    2013-08-08

    KamLAND-Zen is neutrino-less double-beta decay search experiment using enriched 300 kg of {sup 136}Xe dissolved in pure liquid scintillator. This report is purification work of liquid scintillator for KamLAND-Zen experiment before installation in the inner-balloon and background rejection processes after installation.

  1. Continuing the Operation of EXO-200 at WIPP

    SciTech Connect

    Gratta, Giorgio

    2016-02-24

    This grant supported, in part, the operations of the EXO-200 double beta decay experiment at the Waste Isolation Pilot Plant (WIPP) for the period May 1, 2013 to Sept 30, 2015. In this period EXO-200 completed its first phase of data taking, although its operation was disrupted in Feb 2014 by the accidents at WIPP (unrelated to the experiment). The primary goal of the experiment is to search for the very rate (and to date not observed) neutrino-less double beta decay. Such decay, if observed, would shed the light of the quantum-mechanical structure of neutrinos, and the origins of elementary particle masses. Another goal of the detector is to serve as prototype of a larger neutrino-less double beta decay experiment, currently being considered by DOE-OS.

  2. CUORE and beyond: Bolometric techniques to explore inverted neutrino mass hierarchy

    DOE PAGES

    Artusa, D. R.; Avignone, F. T.; Azzolini, O.; ...

    2015-03-24

    The CUORE (Cryogenic Underground Observatory for Rare Events) experiment will search for neutrinoless double beta decay of 130Te. With 741 kg of TeO2 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 × 1026 y at 1σ (9.5 × 1025 y at the 90% confidence level), which corresponds to an upper limit on the effective Majorana mass in the range 40–100 meVmore » (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 130Te and possibly other double beta decay candidate nuclei.« less

  3. CUORE and beyond: Bolometric techniques to explore inverted neutrino mass hierarchy

    SciTech Connect

    Artusa, D. R.; Avignone, F. T.; Azzolini, O.; Balata, M.; Banks, T. I.; Bari, G.; Beeman, J.; Bellini, F.; Bersani, A.; Biassoni, M.; Brofferio, C.; Bucci, C.; Cai, X. Z.; Camacho, A.; Canonica, L.; Cao, X. G.; Capelli, S.; Carbone, L.; Cardani, L.; Carrettoni, M.; Casali, N.; Chiesa, D.; Chott, N.; Clemenza, M.; Copello, S.; Cosmelli, C.; Cremonesi, O.; Creswick, R. J.; Dafinei, I.; Dally, A.; Datskov, V.; De Biasi, A.; Deninno, M. M.; Di Domizio, S.; di Vacri, M. L.; Ejzak, L.; Fang, D. Q.; Farach, H. A.; Faverzani, M.; Fernandes, G.; Ferri, E.; Ferroni, F.; Fiorini, E.; Franceschi, M. A.; Freedman, S. J.; Fujikawa, B. K.; Giachero, A.; Gironi, L.; Giuliani, A.; Goett, J.; Gorla, P.; Gotti, C.; Gutierrez, T. D.; Haller, E. E.; Han, K.; Heeger, K. M.; Hennings-Yeomans, R.; Huang, H. Z.; Kadel, R.; Kazkaz, K.; Keppel, G.; Kolomensky, Yu. G.; Li, Y. L.; Ligi, C.; Liu, X.; Ma, Y. G.; Maiano, C.; Maino, M.; Martinez, M.; Maruyama, R. H.; Mei, Y.; Moggi, N.; Morganti, S.; Napolitano, T.; Nisi, S.; Nones, C.; Norman, E. B.; Nucciotti, A.; O’Donnell, T.; Orio, F.; Orlandi, D.; Ouellet, J. L.; Pallavicini, M.; Palmieri, V.; Pattavina, L.; Pavan, M.; Pedretti, M.; Pessina, G.; Pettinacci, V.; Piperno, G.; Pira, C.; Pirro, S.; Previtali, E.; Rampazzo, V.; Rosenfeld, C.; Rusconi, C.; Sala, E.; Sangiorgio, S.; Scielzo, N. D.; Sisti, M.; Smith, A. R.; Taffarello, L.; Tenconi, M.; Terranova, F.; Tian, W. D.; Tomei, C.; Trentalange, S.; Ventura, G.; Vignati, M.; Wang, B. S.; Wang, H. W.; Wielgus, L.; Wilson, J.; Winslow, L. A.; Wise, T.; Woodcraft, A.; Zanotti, L.; Zarra, C.; Zhu, B. X.; Zucchelli, S.

    2015-03-24

    The CUORE (Cryogenic Underground Observatory for Rare Events) experiment will search for neutrinoless double beta decay of 130Te. With 741 kg of TeO2 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 × 1026 y at 1σ (9.5 × 1025 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 130Te and possibly other double beta decay candidate nuclei.

  4. Status and perspectives of COBRA

    NASA Astrophysics Data System (ADS)

    Fritts, M.; Zuber, K.

    2013-04-01

    The COBRA experiment is a search for neutrinoless double-beta decay using CdZnTe semiconductor detectors. Currently COBRA is collecting data from 32 coplanar grid (CPG) detectors installed in the Gran Sasso National Laboratory. This serves as a prototype for a proposed design of over 100 kg target mass in order to achieve the sensitivity necessary to probe new parameter space for 0νββ. Pixelated detector allowing tracking and thus particle identification are also explored as a unique option in double beta searches.

  5. Inelastic neutrino scattering off stable even-even Mo isotopes at low and intermediate energies

    NASA Astrophysics Data System (ADS)

    Balasi, K. G.; Kosmas, T. S.; Divari, P. C.

    2010-04-01

    Inelastic neutrino scattering cross sections for the even-even Mo isotopes (contents of the MOON detector at Japan), at low and intermediate electron neutrino energies ( ɛi≤100 MeV), are calculated. MOON is a next-generation double beta and neutrino-less double-beta-decay experiment which is also a promising facility for low-energy neutrino detection. The nuclear wave functions required in this work have been constructed in the context of the quasi-particle random phase approximation (QRPA) and the results presented refer to 92Mo, 94Mo, 96Mo, 98Mo and 100Mo isotopes.

  6. Dipole Response of 76Se up to 9 MeV

    NASA Astrophysics Data System (ADS)

    Werner, V.; Cooper, N. M.; Goddard, P. M.; Smith, M. K.; Savran, D.; Yates, S. W.; Crider, B. P.; Peters, E. E.; Chakraborty, A.; Tonchev, A. P.; Rusev, G.; Tornow, W.; Kelley, J. H.; Kwan, E.; Raut, R.; Reichel, F.; Pietralla, N.; Romig, C.; Scheck, M.; Fritzsche, M.; Beller, J.; Zweidinger, M.; Sonnabend, K.

    2013-03-01

    This contribution reports on progress in the measurement of the full dipole excitation strength in 76Se.The experiments used the nuclear resonance fluorescence technique at two facilities, the photon scattering setup at the S-DALINAC at the TU Darmstadt, and the polarization setup at HIGS at TUNL. Data indicates sub-structure of the pygmy dipole resonance, and reveals a candidate for the scissors mode in 76Se. The final aim of the study is the determination of dipole strength distributions in the double-beta decay partners 76Se and 76Ge.

  7. Systematics of Evaluated Half-lives of Double-beta Decay

    SciTech Connect

    Pritychenko, B.

    2014-06-15

    A new evaluation of 2β-decay half lives and their systematics is presented. These data extend the previous evaluation and include the analysis of all recent measurements. The nuclear matrix elements for 2β-decay transitions in 12 nuclei have been extracted. The recommended values are compared with the large-scale shell-model, QRPA calculations, and experimental data. A T{sub 1/2}{sup 2ν}∼1/E{sup 8} systematic trend has been observed for recommended {sup 128,130}Te values. This trend indicates similarities for nuclear matrix elements in Te nuclei and was predicted for 2β(2ν)-decay mode. The complete list of results is available online at (http://www.nndc.bnl.gov/bbdecay/)

  8. Background Studies of CANDLES for Double Beta Decays of 48Ca

    NASA Astrophysics Data System (ADS)

    Kakubata, Hidekazu; Candles Collaboration

    2014-09-01

    An underground observatory is the most effective to perform low background experiments because an underground environment avoids cosmic muon. Backgrounds still remain in this environment, so to grasp their origin and intensity is necessary. We perform the CANDLES experiment in the Kamioka Underground Laboratory to search for 0 νββ of 48Ca, which has the highest Q-value (4.27 MeV) of all ββ nuclides. Here we must consider backgrounds in the energy region around the Q-value. On the CANDLES detector, internal backgrounds from radial contamination in CaF2 crystal scintillators can be restrained to a level free from problems. However, other backgrounds were observed in the energy region higher than the Q-value and peak structure is found in 7 ~ 8 MeV. We inferred that γ-rays emitted by neutron capture reactions on Fe is the main origin of backgrounds. To confirm this hypothesis, we carried out special run using 252Cf neutron source set outside the detector. As a result, we found that the source of these backgrounds is γ-ray from neutron capture on the surrounding material of the detector, especially on the rock and the stainless. For further background reduction, we plan to install additional passive neutron and γ-ray shields. An underground observatory is the most effective to perform low background experiments because an underground environment avoids cosmic muon. Backgrounds still remain in this environment, so to grasp their origin and intensity is necessary. We perform the CANDLES experiment in the Kamioka Underground Laboratory to search for 0 νββ of 48Ca, which has the highest Q-value (4.27 MeV) of all ββ nuclides. Here we must consider backgrounds in the energy region around the Q-value. On the CANDLES detector, internal backgrounds from radial contamination in CaF2 crystal scintillators can be restrained to a level free from problems. However, other backgrounds were observed in the energy region higher than the Q-value and peak structure is found in 7 ~ 8 MeV. We inferred that γ-rays emitted by neutron capture reactions on Fe is the main origin of backgrounds. To confirm this hypothesis, we carried out special run using 252Cf neutron source set outside the detector. As a result, we found that the source of these backgrounds is γ-ray from neutron capture on the surrounding material of the detector, especially on the rock and the stainless. For further background reduction, we plan to install additional passive neutron and γ-ray shields. T. Kishimoto, S. Yoshida, S. Umehara, K. Nakajima, T. Iida, T. Ohata, K. Tetsuno, M. Nomachi, D. Tanaka, T. Maeda, N. Nakatani for the CANDLES Collaboration.

  9. Two-neutrino double-beta decay of 150Nd to excited final states

    NASA Astrophysics Data System (ADS)

    Kidd, Mary; Esterline, James; Finch, Sean; Tornow, Werner

    2013-10-01

    This study yields the first detection of the coincidence gamma rays from the 01+excited state of 150Sm. These gamma rays have energies of 333.97 keV and 406.52 keV, and are emitted in coincidence through a 01+--> 21+--> 0gs+transition. The enriched Nd2O3 sample obtained from Oak Ridge National Laboratory consists of 40.13 g 150Nd. This sample was observed for 642.8 days at the Kimballton Underground Research Facility, producing 21.6 net events in the region of interest. This count rate gives a half life of T1 / 2 = 1 .07-0.25+0.45 (stat) +/- 0 . 07 (syst .) years, which agrees within uncertainties with another recent measurement in which no coincidence was employed. Lower limits were also obtained for decays to higher excited final states. Finally, the nuclear matrix element was extracted from this half life with a value of 0.0232-0.0037+0.0032. This work was supported in part by the US Department of Energy, Office of Nuclear Physics under grant No. DE-FG02-97ER41033.

  10. Two-neutrino double-[beta] decay measurement of [sup 100]Mo

    SciTech Connect

    Dassie, D.; Eschbach, R.; Hubert, F.; Hubert, P.; Isaac, M.C.; Izac, C.; Leccia, F.; Mennrath, P.; Vareille, A. ); Longuemare, C.; Mauger, F. ); Danevich, F.; Kouts, V.; Tretyak, V.I.; Vassilyev, Y.; Zdesenko, Y. ); Barabash, A.S.; Kornoukov, V.N.; Lepikhin, Y.B.; Umatov, V.I.; Vanushin, I.A. ); Augier, C.; Blum, D.; Campagne, J.E.; Jullian, S.; Lalanne, D.; Laplanche, F.; Natchez, F.; Pichenot, G.; Szklarz, G. ); Arnold, R.; Guyonnet, J.L.; Lamhamdi, T.; Linck, I.; Piquemal, F.; Scheibling, F.

    1995-03-01

    From data accumulated over 6140 h with 172 g of enriched molybdenum (1.18 mol yr of [sup 100]Mo) with the NEMO 2 detector in the Frejus Underground Laboratory, a clear [beta][beta]2[nu] signal (1433 events) is observed, leading to a half-life [ital T][sub 1/2]=0.95[plus minus]0.04(stat)[plus minus]0.09(syst) 10[sup 19] yr. The experimental two-electron energy spectrum and the two-electron angular distribution are in agreement with the expected ones. Limits for [beta][beta]0[nu] decays to the ground state, excited states (2[sub 1][sup +] and 0[sub 1][sup +]), and also with Majoron emission are given.

  11. Evidence for neutrino mass: A decade of discovery

    SciTech Connect

    Heeger, Karsten M.

    2004-12-08

    Neutrino mass and mixing are amongst the major discoveries of recent years. From the observation of flavor change in solar and atmospheric neutrino experiments to the measurements of neutrino mixing with terrestrial neutrinos, recent experiments have provided consistent and compelling evidence for the mixing of massive neutrinos. The discoveries at Super-Kamiokande, SNO, and KamLAND have solved the long-standing solar neutrino problem and demand that we make the first significant revision of the Standard Model in decades. Searches for neutrinoless double-beta decay probe the particle nature of neutrinos and continue to place limits on the effective mass of the neutrino. Possible signs of neutrinoless double-beta decay will stimulate neutrino mass searches in the next decade and beyond. I review the recent discoveries in neutrino physics and the current evidence for massive neutrinos.

  12. FLARES: A flexible scintillation light apparatus for rare event searches

    NASA Astrophysics Data System (ADS)

    Sisti, M.; Baldazzi, G.; Bonvicini, V.; Campana, R.; Capelli, S.; Evangelista, Y.; Feroci, M.; Fuschino, F.; Gironi, L.; Labanti, C.; Marisaldi, M.; Previtali, E.; Rignanese, L.; Rachevsky, A.; Vacchi, A.; Zampa, G.; Zampa, N.; Zuffa, M.

    2016-07-01

    FLARES is a project for an innovative detector technology to be applied to rare event searches, and in particular to neutrinoless double beta decay experiments. Its novelty is the enhancement and optimization of the collection of the scintillation light emitted by ultra-pure crystals through the use of arrays of high performance silicon photodetectors cooled to 120 K. This would provide scintillation detectors with 1% level energy resolution, with the advantages of a technology offering relatively simple low cost mass scalability and powerful background reduction handles, as requested by future neutrinoless double beta decay experimental programs. The performances of a first production of matrices of Silicon Drift Detectors are presented and discussed in this paper.

  13. Search for WIMP-Induced Annual Modulation with the CUORE-0 Experiment

    NASA Astrophysics Data System (ADS)

    Lim, Kyungeun; Cuore Collaboration

    2016-09-01

    CUORE-0 was a cryogenic detector that uses an array of tellurium dioxide bolometers with the primary physics goal of searching for neutrinoless double-beta decay of Te-130. CUORE-0 was assembled using new low-background techniques developed for CUORE, which will consist of 19 CUORE-0-like arrays. The first results on the search for neutrinoless double-beta decay with CUORE-0 combined with Cuoricinio, a predecessor to CUORE-0, set the most stringent limit on the half-life of Te-130. Successful background mitigation, along with continuous data acquisition make CUORE-0 also suitable for other low-energy, rare event searches such as dark matter. In this talk, I will present the status and results of the low-energy analysis of CUORE-0. DOE-NP.

  14. Liquid xenon purification, de-radonation (and de-kryptonation)

    SciTech Connect

    Pocar, Andrea

    2015-08-17

    Liquid xenon detectors are at the forefront of rare event physics, including searches for neutrino-less double beta decay and WIMP dark matter. The xenon for these experiments needs to be purified from chemical impurities such as electronegative atoms and molecules, which absorb ionization electrons, and VUV (178 nm) scintillation light-absorbing chemical species. In addition, superb purification from radioactive impurities is required. Particularly challenging are radioactive noble isotopes ({sup 85}Kr,{sup 39,42}Ar,{sup 220,222}Rn). Radon is a particularly universal problem, due to the extended decay sequence of its daughters and its ubiquitous presence in detector materials. Purification and de-radonation of liquid xenon are addressed with particular focus on the experience gained with the EXO-200 neutrino-less double beta decay detector.

  15. Status of the Majorana Demonstrator

    SciTech Connect

    Cuesta, C.; Abgrall, N.; Arnquist, I. J.; Avignone, III, F. T.; Barabash, A. S.; Bertrand, F. E.; Brudanin, V.; Busch, M.; Buuck, M.; Byram, D.; Caldwell, A. S.; Chan, Y. -D.; Christofferson, C. D.; Detwiler, J. A.; Efremenko, Yu.; Ejiri, H.; Elliott, S. R.; Galindo-Uribarri, A.; Giovanetti, G. K.; Goett, J.; Green, M. P.; Gruszko, J.; Guinn, I. S.; Guiseppe, V. E.; Henning, R.; Hoppe, E. W.; Howard, S.; Howe, M. A.; Jasinski, B. R.; Keeter, K. J.; Kidd, M. F.; Konovalov, S. I.; Kouzes, R. T.; LaFerriere, B. D.; Leon, J.; MacMullin, J.; Martin, R. D.; Meijer, S. J.; Mertens, S.; Orrell, J. L.; O'Shaughnessy, C.; Overman, N. R.; Poon, A. W. P.; Radford, D. C.; Rager, J.; Rielage, K.; Robertson, R. G. H.; Romero-Romero, E.; Schmitt, C.; Shanks, B.; Shirchenko, M.; Snyder, N.; Suriano, A. M.; Tedeschi, D.; Timkin, V.; Trimble, J. E.; Varner, R. L.; Vasilyev, S.; Vetter, K.; Vorren, K.; White, B. R.; Wilkerson, J. F.; Wiseman, C.; Xu, W.; Yakushev, E.; Yu, C. -H.; Yumatov, V.

    2015-08-06

    The Majorana Collaboration is constructing the Majorana Demonstrator, an ultra-low background, 40-kg modular high purity Ge detector array to search for neutrinoless double-beta decay in 76Ge. In view of the next generation of tonne-scale Ge-based neutrinoless double-beta decay searches that will probe the neutrino mass scale in the inverted-hierarchy region, a major goal of the Demonstrator is to demonstrate a path forward to achieving a background rate at or below 1 count/tonne/year in the 4 keV region of interest around the Q-value at 2039 keV. Lastly, the current status of the Demonstrator is discussed, as are plans for its completion.

  16. Results and Status of EXO-200

    NASA Astrophysics Data System (ADS)

    Daniels, Tim; Kaufman, Lisa; EXO-200 Collaboration

    2016-09-01

    EXO-200 has provided one of the most sensitive searches for neutrinoless double-beta decay utilizing 175 kg of enriched liquid xenon in an ultra-low background time projection chamber. This detector has demonstrated excellent energy resolution and background rejection capabilities. Using the first two years of data, EXO-200 has set a limit of 1 . 1 ×1025 y at 90% C.L. on the neutrinoless double-beta decay half-life of Xe136. The experiment has experienced a brief hiatus in data taking during a temporary shutdown of its host facility: the Waste Isolation Pilot Plant. EXO-200 has resumed data taking in earnest with upgraded detector electronics. Results from the analysis of EXO-200 data and an update on the current status of EXO-200 will be presented.

  17. Characterization of Silicon Photomultipliers for the nEXO experiment

    NASA Astrophysics Data System (ADS)

    Doria, Luca

    2016-09-01

    The search for the neutrinoless double beta decay represents a test of the MAJORANA nature of neutrinos and at the same time a test of lepton number conservation. Building on the experience gained with the EXO-200 experiment, nEXO is a next generation detector designed for searching neutrinoless double beta decay events with a 5 tonne liquid Xenon time projection chamber (TPC). The detection of this decay requires a very low background experimental setup and excellent energy resolution. In a TPC, both scintillation and ionization signals are detected. For detecting scintillation light from Xenon, silicon photomultipliers (SiPM) represent the currently considered technology. For identifying the appropriate device meeting the nEXO requirements, different state of the art SiPMs are presently characterized using the TRIUMF setup. We will present results on SiPM characterizations regarding their main characteristics: dark noise, afterpulsing and photodetection efficiency in different experimental conditions.

  18. Concept of Metallic Magnetic Calorimeters for Rare Event Search in the LUMINEU Project

    NASA Astrophysics Data System (ADS)

    Loidl, M.; Rodrigues, M.; Navick, X.-F.; Fleischmann, A.; Gastaldo, L.; Enss, C.

    2014-09-01

    The project LUMINEU is mainly aiming at the search for neutrinoless double-beta decay of the candidate nuclide Mo using cryogenic ZnMoO detectors with simultaneous heat and scintillation light detection for radioactive background rejection. It also includes some development for dark matter search using cryogenic Ge detectors with simultaneous heat and ionization detection for background rejection. For both cases, metallic magnetic calorimeters (MMCs) are studied among several thermometer types. In double-beta decay search, the intrinsically fast response of MMCs reading out the light detector may allow for a very fast signal rise time and help to reduce the potential background due to pile-up of two-neutrino double beta decay events. In dark matter search, MMCs reading out the heat channel may improve the energy resolution with respect to the standard NTD Ge thermistor readout and hence the sensitivity of the detectors for low-mass WIMPs.

  19. R and D of crystal scintillators from enriched isotopes for high sensitivity double β decay experiments

    SciTech Connect

    Danevich, F. A.

    2013-12-30

    Experiments to search for neutrinoless double beta decay enters to a new phase when a sensitivity on the level of T{sub 1/2}∼10{sup 26}−10{sup 28} yr is required. Scintillating low temperature detectors possess important properties required for high-sensitivity double beta decay experiments: presence of elements of interest, high energy resolution and detection efficiency, low level of background thanks to excellent particle discrimination ability. High concentration of isotope of interest and as low as possible radioactive contamination are important requirements to crystal scintillators. Other crucial issues are maximal output of detectors and minimal loss of enriched materials. Prospects of several scintillation materials, enriched in isotopes promising for double beta decay experiments, are discussed.

  20. Measurement of the double- β decay half-life of 136Xe with the KamLAND-Zen experiment

    SciTech Connect

    Gando, A.; Gando, Y.; Hanakago, H.; Ikeda, H.; Inoue, K.; Kato, R.; Koga, M.; Matsuda, S.; Mitsui, T.; Nakada, T.; Nakamura, K.; Obata, A.; Oki, A.; Ono, Y.; Shimizu, I.; Shirai, J.; Suzuki, A.; Takemoto, Y.; Tamae, K.; Ueshima, K.; Watanabe, H.; Xu, B. D.; Yamada, S.; Yoshida, H.; Kozlov, A.; Yoshida, S.; Banks, T. I.; Detwiler, J. A.; Freedman, S. J.; Fujikawa, B. K.; Han, K.; O’Donnell, T.; Berger, B. E.; Efremenko, Y.; Karwowski, H. J.; Markoff, D. M.; Tornow, W.; Enomoto, S.; Decowski, M. P.

    2012-04-19

    We present results from the KamLAND-Zen double-beta decay experiment based on an exposure of 77.6 days with 129 kg of 136Xe. The measured two-neutrino double-beta decay half-life of 136Xe is T$2ν\\atop{1/2}$ = 2.38 ± 0.02(stat) ± 0.14(syst) x1021 yr, consistent with a recent measurement by EXO-200. We also obtain a lower limit for the neutrinoless double-beta decay half-life, T$0ν\\atop{1/2}$ > 5.7 x 1024 yr at 90% C.L.

  1. An optimal energy estimator to reduce correlated noise for the EXO-200 light readout

    NASA Astrophysics Data System (ADS)

    Davis, C. G.; Hall, C.; Albert, J. B.; Barbeau, P. S.; Beck, D.; Belov, V.; Breidenbach, M.; Brunner, T.; Burenkov, A.; Cao, G. F.; Cen, W. R.; Chambers, C.; Cleveland, B.; Coon, M.; Craycraft, A.; Daniels, T.; Danilov, M.; Daugherty, S. J.; Davis, J.; Delaquis, S.; Der Mesrobian-Kabakian, A.; DeVoe, R.; Didberidze, T.; Dilling, J.; Dolgolenko, A.; Dolinski, M. J.; Dunford, M.; Fairbank, W., Jr.; Farine, J.; Feldmeier, W.; Feyzbakhsh, S.; Fierlinger, P.; Fudenberg, D.; Gornea, R.; Graham, K.; Gratta, G.; Hughes, M.; Jewell, M. J.; Johnson, A.; Johnson, T. N.; Johnston, S.; Karelin, A.; Kaufman, L. J.; Killick, R.; Koffas, T.; Kravitz, S.; Krücken, R.; Kuchenkov, A.; Kumar, K. S.; Leonard, D. S.; Licciardi, C.; Lin, Y. H.; Ling, J.; MacLellan, R.; Marino, M. G.; Mong, B.; Moore, D.; Njoya, O.; Nelson, R.; Odian, A.; Ostrovskiy, I.; Piepke, A.; Pocar, A.; Prescott, C. Y.; Retière, F.; Rowson, P. C.; Russell, J. J.; Schubert, A.; Sinclair, D.; Smith, E.; Stekhanov, V.; Tarka, M.; Tolba, T.; Tsang, R.; Twelker, K.; Vuilleumier, J.-L.; Waite, A.; Walton, J.; Walton, T.; Weber, M.; Wen, L. J.; Wichoski, U.; Wood, J.; Yang, L.; Yen, Y.-R.; Zeldovich, O. Ya.

    2016-07-01

    The energy resolution of the EXO-200 detector is limited by electronics noise in the measurement of the scintillation response. Here we present a new technique to extract optimal scintillation energy measurements for signals split across multiple channels in the presence of correlated noise. The implementation of these techniques improves the energy resolution of the detector at the neutrinoless double beta decay Q-value from [1.9641 ± 0.0039]% to [1.5820 ± 0.0044]%.

  2. Heat Capacity Setup for Superconducting Bolometer Absorbers below 400 mK

    NASA Astrophysics Data System (ADS)

    Singh, V.; Mathimalar, S.; Dokania, N.; Nanal, V.; Pillay, R. G.; Ramakrishnan, S.

    2014-05-01

    A calorimeter set up with very low heat capacity (20 nJ/K at 100 mK) has been designed using commercial Carbon based resistors. This calorimeter is used to determine the heat capacity of small samples of superconducting bolometer absorbers. In particular, we present heat capacity studies of Tin, a bolometer candidate for Neutrinoless Double Beta Decay in Sn, in the temperature range of 60-400 mK.

  3. Development of NTD Ge Sensors for Superconducting Bolometer

    NASA Astrophysics Data System (ADS)

    Garai, A.; Mathimalar, S.; Singh, V.; Dokania, N.; Nanal, V.; Pillay, R. G.; Ramakrishnan, S.; Shrivastava, A.; Jagadeesan, K. C.; Thakare, S. V.

    2016-08-01

    Neutron transmutation-doped (NTD) Ge sensors have been prepared by irradiating device-grade Ge with thermal neutrons at Dhruva reactor, BARC, Mumbai. These sensors are intended to be used for the study of neutrinoless double beta decay in ^{124}Sn with a superconducting Tin bolometer. Resistance measurements are performed on NTD Ge sensors in the temperature range 100-350 mK. The observed temperature dependence is found to be consistent with the variable-range hopping mechanism.

  4. Development of Cryogenic Bolometer for 0νββ in 124Sn

    NASA Astrophysics Data System (ADS)

    Singh, Vivek; Yashwant, G.; Mathimalar, S.; Dokania, Neha; Nanal, V.; Pillay, R. G.; Datar, V. M.

    2011-11-01

    Cryogenic bolometer detectors, with their high resolution spectroscopy capability, are ideal for neutrino mass experiments as well as for search of rare processes like neutrinoless double beta decay (0νββ) and dark matter. A feasibility study for investigation of 0νββ in 124Sn at the upcoming underground facility of India based Neutrino Observatory (INO) has been initiated. This paper describes endeavors towards cryogenic tin bolometer development.

  5. Seesaw model and two zero flavor neutrino texture

    NASA Astrophysics Data System (ADS)

    Kitabayashi, Teruyuki; Yasuè, Masaki

    2017-03-01

    In the two zero flavor neutrino mass matrix scheme with nonvanishing Majorana effective mass Mee for the neutrinoless double beta decay, four textures are compatible with observed data. We obtain the complete list of the possible textures of four zero Dirac neutrino mass matrix mD in the seesaw mechanism providing these four flavor neutrino textures. Explicit analytical analysis of mD turns out to provide the relation of mD ∝Mee.

  6. Nonzero {theta}{sub 13} for neutrino mixing in a supersymmetric B-L gauge model with T{sub 7} lepton flavor symmetry

    SciTech Connect

    Cao Qinghong; Khalil, Shaaban; Ma, Ernest; Okada, Hiroshi

    2011-10-01

    We discuss how {theta}{sub 13}{ne}0 is accommodated in a recently proposed renormalizable model of neutrino mixing using the non-Abelian discrete symmetry T{sub 7} in the context of a supersymmetric extension of the standard model with gauged U(1){sub B-L}. We predict a correlation between {theta}{sub 13} and {theta}{sub 23}, as well as the effective neutrino mass m{sub ee} in neutrinoless double beta decay.

  7. Investigations in Experimental and Theoretical High Energy Physics

    SciTech Connect

    Krennrich, Frank

    2013-07-29

    We report on the work done under DOE grant DE-FG02-01ER41155. The experimental tasks have ongoing efforts at CERN (ATLAS), the Whipple observatory (VERITAS) and R&D work on dual readout calorimetry and neutrino-less double beta decay. The theoretical task emphasizes the weak interaction and in particular CP violation and neutrino physics. The detailed descriptions of the final report on each project are given under the appropriate task section of this report.

  8. Radiative neutrino model with S U (2 )L triplet fields

    NASA Astrophysics Data System (ADS)

    Nomura, Takaaki; Okada, Hiroshi; Orikasa, Yuta

    2016-12-01

    We propose a loop-induced neutrino mass model, in which we introduce several exotic fermions and bosons with an S U (2 )L multiplet, and discuss various phenomenologies such as lepton flavor violations, the muon anomalous magnetic moment, nonstandard interacting neutrinoless double beta decay, the relic density of dark matter, and the possibility of the spin-independent direct detection searches, imposing the constraints of oblique parameters. And we show a benchmark point to satisfy all the constraints and discuss our predictions.

  9. Muon-induced backgrounds in the CUORICINO experiment

    SciTech Connect

    Andreotti, E.; Arnaboldi, C.; Avignone III, F. T.; Balata, M.; Bandac, I.; Barucci, M.; Beeman, J. W.; Bellini, F.; Bloxham, T.; Brofferio, C.; Bryant, A.; Bucci, C.; Canonica, L.; Capelli, S.; Carbone, L.; Carrettoni, M.; Clemenza, M.; Cremonesi, O.; Creswick, R. J.; Domizio, S. Di; Dolinski, M. J.; Ejzak, L.; Faccini, R.; Farach, H. A.; Ferri, E.; Ferroni, F.; Fiorini, E.; Foggetta, L.; Giachero, A.; Gironi, L.; Giuliani, A.; Gorla, P.; Guardincerri, E.; Gutierrez, T. D.; Haller, E. E.; Kadel, R.; Kazkaz, K.; Kraft, S.; Kogler, L.; Kolomensky, Yu. G.; Maiano, C.; Maruyama, R. H.; Martinez, C.; Martinez, M.; Mizouni, L.; Morganti, S.; Nisi, S.; Nones, C.; Norman, E. B.; Nucciotti, A.; Orio, F.; Pallavicini, M.; Palmieri, V.; Pattavina, L.; Pavan, M.; Pedretti, M.; Pessina, G.; Pirro, S.; Previtali, E.; Risegari, L.; Rosenfeld, C.; Rusconi, C.; Salvioni, C.; Sangiorgio, S.; Schaeffer, D.; Scielzo, N. D.; Sisti, M.; Smith, A. R.; Tomei, C.; Ventura, G.; Vignati, M.

    2010-04-15

    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.

  10. SNO+: Physics program and status update

    NASA Astrophysics Data System (ADS)

    Sibley, L.; SNO+ Collaboration

    2014-06-01

    Joining the current generation of neutrinoless double beta decay experiments, SNO+ is a kilotonne-scale liquid scintillator neutrino detector housed 2 km underground in Vale Canada Ltd's Creighton Mine near Sudbury, Ontario, Canada. Through re-purposing existing hardware in place for the now decommissioned Sudbury Neutrino Observatory (SNO), and employing a rigourous materials purification and selection program, SNO+ will investigate neutrinoless double beta decay of 130Te. Owing to its size, SNO+ expects a sensitivity to the effective Majorana neutrino mass near 100 meV with a 0.3% loading of natural Te and several years of data collection. Designed as a general purpose detector, SNO+ also has a robust physics program that includes investigations of solar and supernova neutrinos, and reactor and geo anti-neutrinos. Construction of the detector is nearly complete, with the first water-fill commissioning phase set to begin at the end of this year and the neutrinoless double beta decay phase following in late 2014.

  11. Simulations toward Effective Calibrations of the CUORE Detector

    NASA Astrophysics Data System (ADS)

    Daniel, Byron; Cuore Collaboration

    2016-09-01

    It is currently unknown whether or not the neutrino is a MAJORANA or Dirac particle, that is, whether or not the neutrino is its own antiparticle. Observing neutrinoless double-beta decay, a process only possible if neutrinos are MAJORANA particles, can answer this question. If observed, this process would indicate that Lepton number is not conserved. CUORE's (Cryogenic Underground Observatory for Rare Events) is a bolometer based detector with Te02 crystal bolometers that is used to search for neutrinoless double-beta decay in 130Te. To insure that this detector will identify the energy peaks resulting from neutrinoless double-beta decay precisely, the detectors must be calibrated with gamma sources. To calibrate the detector, twelve strings carrying the calibration source 232Th were cooled from 300K to 10mK and installed within and around the bolometer towers. Six strings are distributed around the outside of the towers, and six strings are among the towers. This organization of strings was chosen because the gamma ray radiation from the source strings cannot penetrate more than one or two crystals at low energy. I will present the results from Monte Carlo simulations run in order to understand how to calibrate the COURE detector during operations and how to calibrate the CUORE detector in circumstances where the twelve calibration strings fail to deploy properly. Maruyama Group / CUORE collaboration.

  12. SNO+: Physics program and status update

    SciTech Connect

    Sibley, L.; Collaboration: SNO+ Collaboration

    2014-06-24

    Joining the current generation of neutrinoless double beta decay experiments, SNO+ is a kilotonne-scale liquid scintillator neutrino detector housed 2 km underground in Vale Canada Ltd’s Creighton Mine near Sudbury, Ontario, Canada. Through re-purposing existing hardware in place for the now decommissioned Sudbury Neutrino Observatory (SNO), and employing a rigourous materials purification and selection program, SNO+ will investigate neutrinoless double beta decay of {sup 130}Te. Owing to its size, SNO+ expects a sensitivity to the effective Majorana neutrino mass near 100 meV with a 0.3% loading of natural Te and several years of data collection. Designed as a general purpose detector, SNO+ also has a robust physics program that includes investigations of solar and supernova neutrinos, and reactor and geo anti-neutrinos. Construction of the detector is nearly complete, with the first water-fill commissioning phase set to begin at the end of this year and the neutrinoless double beta decay phase following in late 2014.

  13. Germanium-76 Sample Analysis: Revision 3

    SciTech Connect

    Kouzes, Richard T.; Zhu, Zihua; Engelhard, Mark H.

    2011-09-19

    The MAJORANA DEMONSTRATOR is a large array of ultra-low background high-purity germanium detectors, enriched in 76Ge, designed to search for zero-neutrino double-beta decay (0{nu}{beta}{beta}). The DEMONSTRATOR will utilize 76Ge from Russia. The first one-gram sample was received from the supplier for analysis on April 24, 2011. The second one-gram sample was received from the supplier for analysis on July 12, 2011. The third sample, which came from the first large shipment of germanium from the vendor, was received from Oak Ridge National Laboratory (ORNL) on September 13, 2011. The Environmental Molecular Sciences facility, a DOE user facility at PNNL, was used to make the required isotopic and chemical purity measurements that are essential to the quality assurance for the MAJORANA DEMONSTRATOR. The results of these analyses are reported here. The isotopic composition of a sample of natural germanium was also measured twice. Differences in the result between these two measurements led to a re-measurement of the second 76Ge sample.

  14. Understanding the SNO+ Detector

    SciTech Connect

    Kamdin, K.

    2015-03-24

    SNO+, a large liquid scintillator experiment, is the successor of the Sudbury Neutrino Observatory (SNO) experiment. The scintillator volume will be loaded with large quantities of 130Te, an isotope that undergoes double beta decay, in order to search for neutrinoless double beta decay. In addition to this search, SNO+ has a broad physics program due to its sensitivity to solar and supernova neutrinos, as well as reactor and geo anti-neutrinos. SNO+ can also place competitive limits on certain modes of invisible nucleon decay during its first phase. The detector is currently undergoing commissioning in preparation for its first phase, in which the detector is filled with ultra pure water. This will be followed by a pure scintillator phase, and then a Tellurium-loaded scintillator phase to search for neutrinoless double beta decay. Here we present the work done to model detector aging, which was first observed during SNO. The aging was found to reduce the optical response of the detector. We also describe early results from electronics calibration of SNO+.

  15. Understanding the SNO+ Detector

    DOE PAGES

    Kamdin, K.

    2015-03-24

    SNO+, a large liquid scintillator experiment, is the successor of the Sudbury Neutrino Observatory (SNO) experiment. The scintillator volume will be loaded with large quantities of 130Te, an isotope that undergoes double beta decay, in order to search for neutrinoless double beta decay. In addition to this search, SNO+ has a broad physics program due to its sensitivity to solar and supernova neutrinos, as well as reactor and geo anti-neutrinos. SNO+ can also place competitive limits on certain modes of invisible nucleon decay during its first phase. The detector is currently undergoing commissioning in preparation for its first phase, inmore » which the detector is filled with ultra pure water. This will be followed by a pure scintillator phase, and then a Tellurium-loaded scintillator phase to search for neutrinoless double beta decay. Here we present the work done to model detector aging, which was first observed during SNO. The aging was found to reduce the optical response of the detector. We also describe early results from electronics calibration of SNO+.« less

  16. Understanding the SNO+ Detector

    NASA Astrophysics Data System (ADS)

    Kamdin, K.

    SNO+, a large liquid scintillator experiment, is the successor of the Sudbury Neutrino Observatory (SNO) experiment. The scintillator volume will be loaded with large quantities of 130Te, an isotope that undergoes double beta decay, in order to search for neutrinoless double beta decay. In addition to this search, SNO+ has a broad physics program due to its sensitivity to solar and supernova neutrinos, as well as reactor and geo anti-neutrinos. SNO+ can also place competitive limits on certain modes of invisible nucleon decay during its first phase. The detector is currently undergoing commissioning in preparation for its first phase, in which the detector is filled with ultra pure water. This will be followed by a pure scintillator phase, and then a Tellurium-loaded scintillator phase to search for neutrinoless double beta decay. Here we present the work done to model detector aging, which was first observed during SNO. The aging was found to reduce the optical response of the detector. We also describe early results from electronics calibration of SNO+.

  17. Unified description of the double {beta} decay to the first quadrupole phonon state in spherical and deformed nuclei

    SciTech Connect

    Raduta, C. M.; Raduta, A. A.

    2007-10-15

    The Gamow-Teller transition operator is written as a polynomial in the dipole proton-neutron and quadrupole charge-conserving quasiparticle random-phase approximation boson operators, using the prescription of the boson expansion technique. Then, the 2{nu}{beta}{beta} process ending on the first 2{sup +} state in the daughter nucleus is allowed through one-, two-, and three-boson states describing the odd-odd intermediate nucleus. The approach uses a single particle basis that is obtained by projecting out the good angular momentum from an orthogonal set of deformed functions. The basis for mother and daughter nuclei may have different deformations. The GT transition amplitude as well as the half-lives were calculated for 18 transitions. Results are compared with the available data as well as with the predictions obtained with other methods.

  18. Comparison of the pn quasiparticle RPA and shell model for Gamow-Teller beta and double-beta decays

    NASA Astrophysics Data System (ADS)

    Zhao, Liang; Brown, B. Alex

    1993-06-01

    We examine the validity of the pn quasiparticle RPA (pnQRPA) as a model for calculating β+ and 2νββ Gamow-Teller decays by making a comparison of the pnQRPA with a large-basis shell-model calculation within the 0f1p shell. We employ A=46 nuclei (those with six valence nucleons) for this comparison. Our comparison includes the decay matrix elements summed over final states, the strength distributions, and, for the first time, the coherent transition matrix elements (CTME). The pnQRPA overestimates the total β+ and 2νββ matrix elements. There are large differences in the shape of the spectra as well as in the CTME between the pnQRPA and shell-model results. Empirical improvements for the pnQRPA are discussed.

  19. Comparison of the [ital pn] quasiparticle RPA and shell model for Gamow-Teller beta and double-beta decays

    SciTech Connect

    Zhao, L.; Brown, B.A. )

    1993-06-01

    We examine the validity of the [ital pn] quasiparticle RPA ([ital pn]QRPA) as a model for calculating [beta][sup +] and 2[nu][beta][beta] Gamow-Teller decays by making a comparison of the [ital pn]QRPA with a large-basis shell-model calculation within the 0[ital f]1[ital p] shell. We employ [ital A]=46 nuclei (those with six valence nucleons) for this comparison. Our comparison includes the decay matrix elements summed over final states, the strength distributions, and, for the first time, the coherent transition matrix elements (CTME). The [ital pn]QRPA overestimates the total [beta][sup +] and 2[nu][beta][beta] matrix elements. There are large differences in the shape of the spectra as well as in the CTME between the [ital pn]QRPA and shell-model results. Empirical improvements for the [ital pn]QRPA are discussed.

  20. Rejection of randomly coinciding events in Li_2^{100}MoO_4 scintillating bolometers using light detectors based on the Neganov-Luke effect

    NASA Astrophysics Data System (ADS)

    Chernyak, D. M.; Danevich, F. A.; Dumoulin, L.; Giuliani, A.; Mancuso, M.; Marcillac, P. de; Marnieros, S.; Nones, C.; Olivieri, E.; Poda, D. V.; Tretyak, V. I.

    2017-01-01

    Random coincidences of nuclear events can be one of the main background sources in low-temperature calorimetric experiments looking for neutrinoless double-beta decay, especially in those searches based on scintillating bolometers embedding the promising double-beta candidate ^{100} Mo, because of the relatively short half-life of the two-neutrino double-beta decay of this nucleus. We show in this work that randomly coinciding events of the two-neutrino double-beta decay of ^{100} Mo in enriched Li_2^{100} MoO_4 detectors can be effectively discriminated by pulse-shape analysis in the light channel if the scintillating bolometer is provided with a Neganov-Luke light detector, which can improve the signal-to-noise ratio by a large factor, assumed here at the level of {˜ }750 on the basis of preliminary experimental results obtained with these devices. The achieved pile-up rejection efficiency results in a very low contribution, of the order of {˜ }6× 10^{-5} counts/(keV\\cdot kg\\cdot y), to the background counting rate in the region of interest for a large volume ({˜ }90 cm^3) Li_2^{100} MoO_4 detector. This background level is very encouraging in view of a possible use of the Li_2^{100} MoO_4 solution for a bolometric tonne-scale next-generation experiment as that proposed in the CUPID project.

  1. A Linear RFQ Ion Trap for the Enriched Xenon Observatory

    SciTech Connect

    Flatt, B.; Green, M.; Wodin, J.; DeVoe, R.; Fierlinger, P.; Gratta, G.; LePort, F.; Montero Diez, M.; Neilson, R.; O'Sullivan, K.; Pocar, A.; Baussan, E.; Breidenbach, M.; Conley, R.; Fairbank Jr., W.; Farine, J.; Hall, K.; Hallman, D.; Hargrove, C.; Hauger, M.; Hodgson, J.; /Stanford U., Phys. Dept. /Neuchatel U. /SLAC /Colorado State U. /Laurentian U. /Carleton U. /Alabama U.

    2008-01-14

    The design, construction, and performance of a linear radio-frequency ion trap (RFQ) intended for use in the Enriched Xenon Observatory (EXO) are described. EXO aims to detect the neutrinoless double-beta decay of {sup 136}Xe to {sup 136}Ba. To suppress possible backgrounds EXO will complement the measurement of decay energy and, to some extent, topology of candidate events in a Xe filled detector with the identification of the daughter nucleus ({sup 136}Ba). The ion trap described here is capable of accepting, cooling, and confining individual Ba ions extracted from the site of the candidate double-beta decay event. A single trapped ion can then be identified, with a large signal-to-noise ratio, via laser spectroscopy.

  2. Result from, and status of, EXO-200

    NASA Astrophysics Data System (ADS)

    Daniels, Tim; EXO-200 Collaboration

    2017-01-01

    EXO-200 has provided one of the most sensitive searches for neutrinoless double-beta decay utilizing 175 kg of enriched liquid xenon in an ultra-low background time projection chamber. This detector has demonstrated excellent energy resolution and background rejection capabilities. Using the first two years of data, EXO-200 has set a limit of 1 . 1 ×1025 y at 90 double-beta decay half-life of 136Xe. The experiment has experienced a brief hiatus in data taking during a temporary shutdown of its host facility: the Waste Isolation Pilot Plant. EXO-200 has resumed data taking in earnest with upgraded detector electronics. Results from the analysis of EXO-200 data and an update on the current status of EXO-200 will be presented.

  3. Estimation of Equivalent Sea Level Cosmic Ray Exposure for Low Background Experiment

    SciTech Connect

    Greene, Austen T.; Orrell, John L.

    2012-08-25

    While scientists at CERN and other particle accelerators around the world explore the boundaries of high energy physics, the Majorana project investigates the other end of the spectrum with its extremely sensitive, low background, low energy detector. The MAJORANA DEMONSTRATOR aims to detect neutrinoless double beta decay (0νββ), a rare theoretical process in which two neutrons decay into two protons and two electrons, without the emission of the two antineutrinos that are a product of a normal double beta decay. This process is only possible if – and therefore a detection would prove — the neutrino is a Majorana particle, meaning that it is its own antiparticle [Aaselth et al. 2004] . The existence of such a decay would also disprove lepton conservation and give information about the neutrino's mass.

  4. Neutrino scattering off the stable even-even Mo isotopes

    NASA Astrophysics Data System (ADS)

    Balasi, K. G.; Kosmas, T. S.; Divari, P. C.

    2009-11-01

    Inelastic neutrino-nucleus reaction cross sections are studied focusing on the neutral current processes. Particularly, we investigate the angular and initial neutrino-energy dependence of the differential and integrated cross sections for low and intermediate energies of the incoming neutrino. The nuclear wave functions for the initial and final nuclear states are constructed in the context of the quasi-particle random phase approximation (QRPA) tested on the reproducibility of the low-lying energy spectrum. The results presented here refer to the isotopes Mo92, Mo94, Mo96, Mo98 and Mo100. These isotopes could play a significant role in supernova neutrino detection in addition to their use in double-beta and neutrinoless double-beta decay experiments (e.g. MOON, NEMO III).

  5. Majorana Electroformed Copper Mechanical Analysis

    SciTech Connect

    Overman, Nicole R.; Overman, Cory T.; Kafentzis, Tyler A.; Edwards, Danny J.; Hoppe, Eric W.

    2012-04-30

    The MAJORANA DEMONSTRATOR is a large array of ultra-low background high-purity germanium detectors, enriched in 76Ge, designed to search for zero-neutrino double-beta decay. The DEMONSTRATOR will utilize ultra high purity electroformed copper for a variety of detector components and shielding. A preliminary mechanical evaluation was performed on the Majorana prototype electroformed copper material. Several samples were removed from a variety of positions on the mandrel. Tensile testing, optical metallography, scanning electron microscopy, and hardness testing were conducted to evaluate mechanical response. Analyses carried out on the Majorana prototype copper to this point show consistent mechanical response from a variety of test locations. Evaluation shows the copper meets or exceeds the design specifications.

  6. Neutron Spallation Measurements And Impacts On Low Background Experiments

    SciTech Connect

    Aguayo, Estanislao; Kouzes, Richard T.; Siciliano, Edward R.

    2014-09-01

    Ultra-low background experiments, such as neutrinoless double beta decay, carried out deep underground to escape cosmic ray backgrounds can nonetheless be limited in sensitivity by cosmogenically induced signals. This limit can either be produced directly during operation from cosmic muon events in the detector volume, or can be produced by radioactive decay of cosmogenically generated radionuclides created while the detector materials were above ground. An accurate knowledge of the production of the latter source of background is of paramount importance in order to be able to interpret the results of low-background experiments.

  7. The Majorana Project

    SciTech Connect

    Orrell, John; Hoppe, Eric

    2013-11-20

    Working as part of a collaborative team, PNNL is bringing its signature capability in ultra-low-level detection to help search for a rare form of radioactive decay-never before detected-called "neutrinoless double beta decay" in germanium. If observed, it would demonstrate neutrinos are Majorana-type particles. This discovery would show neutrinos are unique among fundamental particles, having a property whereby the matter and anti-matter version of this particle are indistinguishable. Physicist John L. Orrell explains how they rely on the Shallow Underground Laboratory to conduct the research.

  8. Status of the SNO+ experiment

    NASA Astrophysics Data System (ADS)

    Kaspar, Jarek; SNO+ Collaboration

    2011-10-01

    SNO+ is a large liquid scintillator detector following the successful SNO experiment with liquid scintillator replacing the heavy water. Located 2 km underground in Vale nickel mine in Sudbury, Canada, the experiment will detect solar neutrinos including the pep and CNO neutrinos, neutrinos from Earth, reactors, and supernovae. In addition, the experiment will search for neutrino-less double beta decay by adding 150-Nd to the scintillator. I will present the status of the experiment. The research has been supported under DOE Grant #DE-FG02-97ER41020.

  9. Scintillating Bolometer Monte Carlo for Rare Particle Event Searches

    NASA Astrophysics Data System (ADS)

    Deporzio, Nicholas

    2016-09-01

    This study uses the Geant4 physics simulation toolkit to characterize various scintillating bolometer constructions for potential experimental commissioning. Emphasis is placed on detector sensitivity to neutrinoless double-beta decay. Constructions minimally include a scintillating source material for the decay and an absorber material. Tellurium, Selenium, Germanium and other candidate isotopes are studied as source materials. Various background discrimination techniques are analyzed including reflective housings and anti-reflective coatings upon the source material. Different geometric optimizations are considered. Ability to discriminate incident alpha and beta radiation, as well as photon detection efficiency for each construction is presented.

  10. Radon reduction and radon monitoring in the NEMO experiment

    SciTech Connect

    Nachab, A.

    2007-03-28

    The first data of the NEMO 3 neutrinoless double beta decay experiment have shown that the radon can be a non negligible component of the background. In order to reduce the radon level in the gas mixture, it has been necessary first to cover the NEMO 3 detector with an airtight tent and then to install a radon-free air factory. With the use of sensitive radon detectors, the level of radon at the exit of the factory and inside the tent is continuously controlled. These radon levels are discussed within the NEMO 3 context.

  11. Present Status and Future Perspectives of the NEXT Experiment

    DOE PAGES

    Gómez Cadenas, J. J.; Álvarez, V.; Borges, F. I. G.; ...

    2014-01-01

    NEXT is an experiment dedicated to neutrinoless double beta decay searches in xenon. The detector is a TPC, holding 100 kg of high-pressure xenon enriched in the136Xe isotope. It is under construction in the Laboratorio Subterráneo de Canfranc in Spain, and it will begin operations in 2015. The NEXT detector concept provides an energy resolutionbetter than 1% FWHM and a topological signal that can be used to reduce the background. Furthermore, the NEXT technology can be extrapolated to a 1 ton-scale experiment.

  12. NUMEN Project @ LNS : Heavy ions double charge exchange reactions towards the 0νββ nuclear matrix element determination

    SciTech Connect

    Agodi, C. Calabretta, L.; Calanna, A.; Carbone, D.; Cavallaro, M.; Colonna, M.; Cuttone, G.; Finocchiaro, P.; Pandola, L.; Rifuggiato, D.; Tudisco, S.; Cappuzzello, F.; Greco, V.; Bonanno, D. L.; Bongiovanni, D. G.; Longhitano, F.; Branchina, V.; Foti, A.; Lo Presti, D.; Lanzalone, G.; and others

    2015-10-28

    In the NUMEN Project it is proposed an innovative technique to access the nuclear matrix elements entering in the expression of the life-time of the neutrinoless double beta decay, using relevant cross sections of double charge exchange reactions. A key aspect is the use of MAGNEX large acceptance magnetic spectrometer, for the detection of the ejectiles, and of the INFN Laboratori Nazionali del Sud (LNS) K800 Superconducting Cyclotron (CS), for the acceleration of the required high resolution and low emittance heavy-ion beams.

  13. The CUORE cryostat and its bolometric detector

    NASA Astrophysics Data System (ADS)

    Santone, D.; Alduino, C.; Alfonso, K.; Artusa, D. R.; Avignone, F. T., III; Azzolini, O.; Banks, T. I.; Bari, G.; Beeman, J. W.; Bellini, F.; Bersani, A.; Biassoni, M.; Branca, A.; Brofferio, C.; Bucci, C.; Camacho, A.; Caminata, A.; Canonica, L.; Cao, X. G.; Capelli, S.; Cappelli, L.; Carbone, L.; Cardani, L.; Carniti, P.; Casali, N.; Cassina, L.; Chiesa, D.; Chott, N.; Clemenza, M.; Copello, S.; Cosmelli, C.; Cremonesi, O.; Creswick, R. J.; Cushman, J. S.; D'Addabbo, A.; Dafinei, I.; Davis, C. J.; Dell'Oro, S.; Deninno, M. M.; Di Domizio, S.; Di Vacri, M. L.; Drobizhev, A.; Fang, D. Q.; Faverzani, M.; Fernandes, G.; Ferri, E.; Ferroni, F.; Fiorini, E.; Franceschi, M. A.; Freedman, S. J.; Fujikawa, B. K.; Giachero, A.; Gironi, L.; Giuliani, A.; Gladstone, L.; Gorla, P.; Gotti, C.; Gutierrez, T. D.; Haller, E. E.; Han, K.; Hansen, E.; Heeger, K. M.; Hennings-Yeomans, R.; Hickerson, K. P.; Huang, H. Z.; Kadel, R.; Keppel, G.; Kolomensky, Yu. G.; Leder, A.; Ligi, C.; Lim, K. E.; Liu, X.; Ma, Y. G.; Maino, M.; Marini, L.; Martinez, M.; Maruyama, R. H.; Mei, Y.; Moggi, N.; Morganti, S.; Mosteiro, P. J.; Napolitano, T.; Nones, C.; Norman, E. B.; Novati, V.; Nucciotti, A.; O'Donnell, T.; Orio, F.; Ouellet, J. L.; Pagliarone, C. E.; Pallavicini, M.; Palmieri, V.; Pattavina, L.; Pavan, M.; Pessina, G.; Pettinacci, V.; Piperno, G.; Pira, C.; Pirro, S.; Pozzi, S.; Previtali, E.; Rosenfeld, C.; Rusconi, C.; Sangiorgio, S.; Scielzo, N. D.; Singh, V.; Sisti, M.; Smith, A. R.; Taffarello, L.; Tenconi, M.; Terranova, F.; Tomei, C.; Trentalange, S.; Vignati, M.; Wagaarachchi, S. L.; Wang, B. S.; Wang, H. W.; Wilson, J.; Winslow, L. A.; Wise, T.; Woodcraft, A.; Zanotti, L.; Zhang, G. Q.; Zhu, B. X.; Zimmermann, S.; Zucchelli, S.

    2017-02-01

    CUORE is a cryogenic detector that will be operated at LNGS to search for neutrinoless double beta decay (0νββ) of 130Te. The detector installation was completed in summer 2016. Before the installation, several cold runs were done to test the cryogenic system performance. In the last cold run the base temperature of 6.3 mK was reached in stable condition. CUORE-0, a CUORE prototype, has proven the feasibility of CUORE, demonstrating that the target background of 0.01 counts/keV/kg/y and the energy resolution of 5 keV are within reach.

  14. Are neutrinos their own antiparticles?

    SciTech Connect

    Kayser, Boris; /Fermilab

    2009-03-01

    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.

  15. μ--e+ conversion in upcoming LFV experiments

    NASA Astrophysics Data System (ADS)

    Geib, Tanja; Merle, Alexander; Zuber, Kai

    2017-01-01

    We present an illustrative discussion of the physics potential of μ--e+ conversion. We point out that this process, although much less frequently studied than the related but much more popular processes of μ--e- conversion and neutrinoless double beta decay, may in fact be a promising alternative to detect both lepton flavour and number violation. However, for this goal to be reached, a combined effort of experiments and theory, both in nuclear and particle physics, is necessary to advance. The aim of this paper is to be an "appetiser" to trigger such an initiative.

  16. Robust Signal Extraction Methods and Monte Carlo Sensitivity Studies for the Sudbury Neutrino Observatory and SNO+ Experiments

    NASA Astrophysics Data System (ADS)

    Wright, Alexander Joseph

    The third and final phase of the Sudbury Neutrino Observatory (SNO) experiment utilized a series of 3He proportional counters called Neutral Current Detectors (NCDs) to detect the neutrons produced by the neutral current interactions of solar neutrinos in the detector. The number of neutrons detected by the NCDs, and hence the total flux of 8B solar neutrinos, has been determined using two novel signal extraction techniques which were designed to be robust against potential unexpected behaviour in the NCD background. These techniques yield total 8B solar neutrino flux measurements of 5.04+0.42-0.40 (stat) +/- 0.28(syst)x106cm -2s-1 and (4.40-6.43)x106cm-2 s-1, which are in good agreement with previous SNO results and with solar model predictions, and which confirm that previous NCD analyses were not unduly affected by unexpected background behaviour. The majority of the hardware from the now-completed SNO experiment will be reused to create a new liquid scintillator based neutrino experiment called SNO+. An important part of the SNO+ physics program will be a search for neutrinoless double beta decay, carried out by dissolving 150Nd into the scintillator. The sensitivity of the SNO+ experiment to neutrinoless double beta decay has been evaluated. If loaded at 0.1% (w/w) with natural neodymium, after 1 kT·a of data taking SNO+ would have a 90%C.L. sensitivity of T0n1/2 > 8.0x1024 a or better 50% of the time; if the experiment were run with neodymium enriched to 50% in 150Nd this limit improves to 57x1024 a. Under a reasonable choice for the 150Nd neutrinoless double beta decay matrix element, these half lives correspond to upper limits on the effective Majorana neutrino mass of 112 meV and 42 meV, respectively. These limits are competitive with those expected from all other near-term neutrinoless double beta decay experiments.

  17. Characterization of a large CdZnTe detector with a coplanar quad-grid design

    NASA Astrophysics Data System (ADS)

    Theinert, R.

    2017-02-01

    The COBRA collaboration aims to search for neutrinoless double beta-decays of several isotopes using CdZnTe semiconductor detectors. To improve the sensitivity on the half-lifes of such decays, a large (2 × 2 × 1.5)cm3 CdZnTe detector for applications in gamma-ray spectroscopy and low-background operation is investigated. The electric properties as well as the spectroscopic performance of the detector, such as energy response and resolution, are characterized. In addition, several measurements are conducted to investigate the operational stability. Furthermore, the possibility to identify multiple-scattered gamma-rays with the new anode design is studied.

  18. Automation of the Characterization of High Purity Germanium Detectors

    NASA Astrophysics Data System (ADS)

    Dugger, Charles ``Chip''

    2014-09-01

    Neutrinoless double beta decay is a rare hypothesized process that may yield valuable insight into the fundamental properties of the neutrino. Currently there are several experiments trying to observe this process, including the Majorana DEMONSTRAOR experiment, which uses high purity germanium (HPGe) detectors to generate and search for these events. Because the event happens internally, it is essential to have the lowest background possible. This is done through passive detector shielding, as well as event discrimination techniques that distinguish between multi-site events characteristic of gamma-radiation, and single-site events characteristic of neutrinoless double beta decay. Before fielding such an experiment, the radiation response of the detectors must be characterized. A robotic arm is being tested for future calibration of HPGe detectors. The arm will hold a source at locations relative to the crystal while data is acquired. Several radioactive sources of varying energy levels will be used to determine the characteristics of the crystal. In this poster, I will present our work with the robot, as well as the characterization of data we took with an underground HPGe detector at the WIPP facility in Carlsbad, NM (2013). Neutrinoless double beta decay is a rare hypothesized process that may yield valuable insight into the fundamental properties of the neutrino. Currently there are several experiments trying to observe this process, including the Majorana DEMONSTRAOR experiment, which uses high purity germanium (HPGe) detectors to generate and search for these events. Because the event happens internally, it is essential to have the lowest background possible. This is done through passive detector shielding, as well as event discrimination techniques that distinguish between multi-site events characteristic of gamma-radiation, and single-site events characteristic of neutrinoless double beta decay. Before fielding such an experiment, the radiation response of

  19. Low Background Signal Readout Electronics for the MAJORANA DEMONSTRATOR

    SciTech Connect

    Guinn, I.; Abgrall, N.; Avignone, III, F. T.; Efremenko, Yuri; Galindo-Uribarri, A; Green, M. P.; Radford, D. C.; Romero-Romero, E.; White, B. R.; Wilkerson, J. F.; Majorana,

    2015-01-01

    The MAJORANA DEMONSTRATOR is a planned 40 kg array of Germanium detectors intended to demonstrate the feasibility of constructing a tonne-scale experiment that will seek neutrinoless double beta decay (0 nu beta beta) in Ge-76. Such an experiment would require backgrounds of less than 1 count/tonne-year in the 4 keV region of interest around the 2039 keV Q-value of the beta beta decay. Designing low-noise electronics, which must be placed in close proximity to the detectors, presents a challenge to reaching this background target. This paper will discuss the MAJORANA collaboration's solutions to some of these challenges.

  20. CUORE-0 detector: design, construction and operation

    NASA Astrophysics Data System (ADS)

    Alduino, C.; Alfonso, K.; Artusa, D. R.; Avignone, F. T., III; Azzolini, O.; Balata, M.; Banks, T. I.; Bari, G.; Beeman, J. W.; Bellini, F.; Bersani, A.; Biare, D.; Biassoni, M.; Bragazzi, F.; Brofferio, C.; Buccheri, A.; Bucci, C.; Bulfon, C.; Caminata, A.; Canonica, L.; Cao, X. G.; Capelli, S.; Capodiferro, M.; Cappelli, L.; Carbone, L.; Cardani, L.; Cariello, M.; Carniti, P.; Casali, N.; Cassina, L.; Cereseto, R.; Ceruti, G.; Chiarini, A.; Chiesa, D.; Chott, N.; Clemenza, M.; Conventi, D.; Copello, S.; Cosmelli, C.; Cremonesi, O.; Creswick, R. J.; Cushman, J. S.; D'Addabbo, A.; Dafinei, I.; Davis, C. J.; Dell'Oro, S.; Deninno, M. M.; Di Domizio, S.; Di Vacri, M. L.; DiPaolo, L.; Drobizhev, A.; Erme, G.; Fang, D. Q.; Faverzani, M.; Fernandes, G.; Ferri, E.; Ferroni, F.; Fiorini, E.; Freedman, S. J.; Fujikawa, B. K.; Gaigher, R.; Giachero, A.; Gironi, L.; Giuliani, A.; Gladstone, L.; Gorla, P.; Gotti, C.; Guetti, M.; Gutierrez, T. D.; Haller, E. E.; Han, K.; Hansen, E.; Heeger, K. M.; Hennings-Yeomans, R.; Hickerson, K. P.; Huang, H. Z.; Iannone, M.; Ioannucci, L.; Kadel, R.; Keppel, G.; Kolomensky, Yu. G.; Leder, A.; Lim, K. E.; Liu, X.; Ma, Y. G.; Maino, M.; Marini, L.; Martinez, M.; Maruyama, R. H.; Mazza, R.; Mei, Y.; Meijer, S.; Michinelli, R.; Miller, D.; Moggi, N.; Morganti, S.; Mosteiro, P. J.; Nastasi, M.; Nisi, S.; Nones, C.; Norman, E. B.; Nucciotti, A.; O'Donnell, T.; Orio, F.; Orlandi, D.; Ouellet, J. L.; Pagliarone, C. E.; Pallavicini, M.; Palmieri, V.; Pancaldi, G.; Pattavina, L.; Pavan, M.; Pedrotta, R.; Pelosi, A.; Perego, M.; Pessina, G.; Pettinacci, V.; Piperno, G.; Pirro, S.; Pozzi, S.; Previtali, E.; Rosenfeld, C.; Rusconi, C.; Sala, E.; Sangiorgio, S.; Santone, D.; Scielzo, N. D.; Singh, V.; Sisti, M.; Smith, A. R.; Stivanello, F.; Taffarello, L.; Tatananni, L.; Tenconi, M.; Terranova, F.; Tessaro, M.; Tomei, C.; Trentalange, S.; Ventura, G.; Vignati, M.; Wagaarachchi, S. L.; Wallig, J.; Wang, B. S.; Wang, H. W.; Wilson, J.; Winslow, L. A.; Wise, T.; Zanotti, L.; Zarra, C.; Zhang, G. Q.; Zhu, B. X.; Zimmermann, S.; Zucchelli, S.

    2016-07-01

    The CUORE experiment will search for neutrinoless double-beta decay of 130Te with an array of 988 TeO2 bolometers arranged in 19 towers. CUORE-0, the first tower assembled according to the CUORE procedures, was built and commissioned at Laboratori Nazionali del Gran Sasso, and took data from March 2013 to March 2015. In this paper we describe the design, construction and operation of the CUORE-0 experiment, with an emphasis on the improvements made over a predecessor experiment, Cuoricino. In particular, we demonstrate with CUORE-0 data that the design goals of CUORE are within reach.

  1. Neutrinos in Nuclear Physics

    SciTech Connect

    McKeown, Bob

    2015-06-01

    Since the discovery of nuclear beta decay, nuclear physicists have studied the weak interaction and the nature of neutrinos. Many recent and current experiments have been focused on the elucidation of neutrino oscillations and neutrino mass. The quest for the absolute value of neutrino mass continues with higher precision studies of the tritium beta decay spectrum near the endpoint. Neutrino oscillations are studied through measurements of reactor neutrinos as a function of baseline and energy. And experiments searching for neutrinoless double beta decay seek to discover violation of lepton number and establish the Majorana nature of neutrino masses.

  2. The Majorana Project

    ScienceCinema

    Orrell, John; Hoppe, Eric

    2016-07-12

    Working as part of a collaborative team, PNNL is bringing its signature capability in ultra-low-level detection to help search for a rare form of radioactive decay-never before detected-called "neutrinoless double beta decay" in germanium. If observed, it would demonstrate neutrinos are Majorana-type particles. This discovery would show neutrinos are unique among fundamental particles, having a property whereby the matter and anti-matter version of this particle are indistinguishable. Physicist John L. Orrell explains how they rely on the Shallow Underground Laboratory to conduct the research.

  3. Neutrinos beyond the Standard Model

    SciTech Connect

    Valle, J.W.F.

    1989-08-01

    I review some basic aspects of neutrino physics beyond the Standard Model such as neutrino mixing and neutrino non-orthogonality, universality and CP violation in the lepton sector, total lepton number and lepton flavor violation, etc.. These may lead to neutrino decays and oscillations, exotic weak decay processes, neutrinoless double /beta/ decay, etc.. Particle physics models are discussed where some of these processes can be sizable even in the absence of measurable neutrino masses. These may also substantially affect the propagation properties of solar and astrophysical neutrinos. 39 refs., 4 figs.

  4. Connecting Dirac and Majorana neutrino mass matrices in the minimal left-right symmetric model.

    PubMed

    Nemevšek, Miha; Senjanović, Goran; Tello, Vladimir

    2013-04-12

    Probing the origin of neutrino mass by disentangling the seesaw mechanism is one of the central issues of particle physics. We address it in the minimal left-right symmetric model and show how the knowledge of light and heavy neutrino masses and mixings suffices to determine their Dirac Yukawa couplings. This in turn allows one to make predictions for a number of high and low energy phenomena, such as decays of heavy neutrinos, neutrinoless double beta decay, electric dipole moments of charged leptons, and neutrino transition moments. We also discuss a way of reconstructing the neutrino Dirac Yukawa couplings at colliders such as the LHC.

  5. Background Models for Muons and Neutrons Underground

    SciTech Connect

    Formaggio, Joseph A.

    2005-09-08

    Cosmogenic-induced activity is an issue of great concern for many sensitive experiments sited underground. A variety of different arch-type experiments - such as those geared toward the detection of dark matter, neutrinoless double beta decay and solar neutrinos - have reached levels of cleanliness and sensitivity that warrant careful consideration of secondary activity induced by cosmic rays. This paper reviews some of the main issues associated with the modeling of cosmogenic activity underground. Comparison with data, when such data is available, is also presented.

  6. Dark matter search with CUORE-0 and CUORE

    DOE PAGES

    Aguirre, C. P.; Artusa, D. R.; Avignone, F. T.; ...

    2015-01-01

    The Cryogenic Underground Observatory for Rare Events (CUORE) is a ton-scale experiment made of TeO₂ bolometers that will probe the neutrinoless double beta decay of ¹³⁰Te. Excellent energy resolution, low threshold and low background make CUORE sensitive to nuclear recoils, allowing a search for dark matter interactions. With a total mass of 741 kg of TeO₂, CUORE can search for an annual modulation of the counting rate at low energies. We present data obtained with CUORE-like detectors and the prospects for a dark matter search in CUORE-0, a 40-kg prototype, and CUORE.

  7. Muon-induced backgrounds in the CUORICINO experiment

    SciTech Connect

    Andreotti, E; Arnaboldi, C; Avignone, F T; Balata, M; Bandac, I; Barucci, M; Beeman, J W; Bellini, F; Bloxham, T; Brofferio, C; Bryant, A; Bucci, C; Canonica, L; Capelli, S; Carbone, L; Carrettoni, M; Clemenza, M; Cremonesi, O; Creswick, R J; Domizio, S D; Dolinski, M J; Ejzak, L; Faccini, R; Farach, H A; Ferri, E; Ferroni, F; Firoini, E; Foggetta, L; Giachero, A; Gironi, L; Giuliani, A; Gorla, P; Guardincerri, E; Gutierrez, T D; Haller, E E; Kadel, R; Kazkaz, K; Kraft, S; Kogler, L; Kolomensky, Y G; Maiano, C; Maruyama, R H; Martinez, C; Martinez, M; Mizouni, L; Morganti, S; Nisi, S; Nones, C; Norman, E B; Nucciotti, A; Orio, F; Pallavicini, M; Palmieri, V; Pattavina, L; Pavan, M; Pedretti, M; Pessina, G; Pirro, S; Previtali, E; Risegari, L; Rosenfeld, C; Rusconi, C; Salvioni, C; Sangiorgio, S; Schaeffer, D; Scielzo, N D; Sisti, M; Smith, A R; Tomei, C; Ventura, G; Vignati, M

    2009-11-16

    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.

  8. Scintillating Bolometer Monte Carlo for Rare Particle Event Searches

    NASA Astrophysics Data System (ADS)

    Deporzio, Nicholas

    2017-01-01

    This study uses the Geant4 physics simulation toolkit to characterize various scintillating bolometer constructions for potential experimental commissioning. Emphasis is placed on detector sensitivity to neutrinoless double-beta decay. Constructions minimally include a scintillating source material for the decay and an absorber material. Tellurium, Selenium, Germanium and other candidate isotopes are studied as source materials. Various background discrimination techniques are analyzed including reflective housings and anti-reflective coatings upon the source material. Different geometric optimizations are considered. Ability to discriminate incident alpha and beta radiation, as well as photon detection efficiency for each construction is presented.

  9. Investigation of the backgrounds in the EXO-200 experiment

    NASA Astrophysics Data System (ADS)

    Didberidze, Tamar; EXO-200 Collaboration

    2015-04-01

    The Enriched Xenon Observatory EXO-200 experiment currently located at Waste Isolation Pilot Plant (WIPP) in New Mexico, which uses a 175 kg of isotopically enriched 136 Xe, is designed to search for the neutrinoless double beta decay (0 νββ) in 136 Xe. The search for this type of decay requires a good understanding of background sources. I will present results of the background study done for the EXO-200 experiment. The study has been performed using a current EXO-200 low-background data and model to estimate the location and magnitude of background sources and compared to the radio assay results that were obtained before detector construction.

  10. Status of selected neutrinoless ββ-decay experiments

    NASA Astrophysics Data System (ADS)

    Avignone, F. T.; Brodzinski, R. L.; Reeves, J. H.; Miley, H. S.

    1988-11-01

    A brief update is given on a number of ongoing Oν ββ-decay experiments. Progress is reported in background reduction, limits are given on the various modes of decay, and projections of potential sensitivity are made in some cases. In particular, a new result from the PNL-USC Oν ββ decay experiment yields a half-life of (3.2+2.2-1.2)×1021 y (1σ) for decay with the emission of a majoron. While a positive result is still observed, it is now statistically less significant. A new recently deep-mined Ge to decrease background cosmogenic radioactivity.

  11. Status of the MAJORANA DEMONSTRATOR

    SciTech Connect

    Cuesta, C; Abgrall, N.; Arnquist, I. J.; Avignone, III, F. T.; Barabash, A.S.; Bertrand, F. E.; Bradley, A. W.; Brudanin, V.; Busch, M.; Byram, D.; Caldwell, Adam S; Chan, Y-D; Christofferson, C. D.; Chu, P.-H.; Detwiler, J. A.; Efremenko, Yu.; Ejiri, H.; Elliott, S. R.; Galindo-Uribarri, A; Gilliss, T.; Green, M. P.; Gruszko, J; Guinn, I S; Guiseppe, V E; Henning, R.; Howard, S.; Howe, M. A.; Keeter, K.J.; Kidd, M. F.; Konovalov, S.I.; Kouzes, R. T.; LaFerriere, B. D.; Leon, J.; MacMullin, J.; Massarczyk, R.; Meijer, S. J.; Orrell, J. L.; O'Shaughnessy, C.; Radford, D. C.; Rager, J.; Robertson, R.G.H.; Romero-Romero, E.; Snyder, N; Suriano, A. M.; Tedeschi, D; Trimble, J. E.; Vasilyev, S.; et al.

    2015-01-01

    The MAJORANA Collaboration is constructing the MAJORANA DEMONSTRATOR, an ultra-low background, modular, HPGe detector array with a mass of 44-kg (29 kg Ge-76 and 15 kg Ge-nat) to search for neutrinoless double beta decay in Ge-76. The next generation of tonne-scale Ge-based neutrinoless double beta decay searches will probe the neutrino mass scale in the inverted-hierarchy region. The MAJORANA DEMONSTRATOR is envisioned to demonstrate a path forward to achieve a background rate at or below 1 count/tonne/year in the 4 keV region of interest around the Q-value of 2039 keV. The MAJO-RANA DEMONSTRATOR follows a modular implementation to be easily scalable to the next generation experiment. First, the prototype module was assembled; it has been continuously taking data from July 2014 to June 2015. Second, Module 1 with more than half of the total enriched detectors and some natural detectors has been assembled and it is being commissioned. Finally, the assembly of Module 2, which will complete MAJORANA DEMONSTRATOR, is already in progress.

  12. Optimizing the CUORE data processing in search for 0 νββ decay

    NASA Astrophysics Data System (ADS)

    Schmidt, Benjamin; Cuore Collaboration

    2016-09-01

    The search for neutrino-less double beta decay (0 νββ) may allow us to understand the Dirac or MAJORANA nature of the neutrino, constrain its mass and provide insight into the origin of the matter-antimatter asymmetry in the Universe. The Cryogenic Underground Observatory for Rare Events (CUORE) is a 0 νββ decay search experiment currently being installed deep underground at the Laboratori Nazionali del Gran Sasso (LNGS). It is going to house an array of 988 TeO2 crystals with a total mass of 741 kg. It is designed to reach a sensitivity on the neutrino-less double beta decay half life of 130Te of T1 / 2 = 9 . 5 ×1025 (90% C.L.) after 5 years of data taking. A data analysis pipeline has been prepared and successfully used for the recently concluded prototype experiment CUORE-0. In this talk we will focus on the challenge of further automatizing and extending the processing from a single tower of 52 bolometers to the analysis of the data from 988 individual detectors. We will give an update on this work and a first evaluation of several improvements.

  13. Low and high energy phenomenology of quark-lepton complementarity scenarios

    SciTech Connect

    Hochmuth, Kathrin A.; Rodejohann, Werner

    2007-04-01

    We conduct a detailed analysis of the phenomenology of two predictive seesaw scenarios leading to quark-lepton complementarity. In both cases we discuss the neutrino mixing observables and their correlations, neutrinoless double beta decay and lepton flavor violating decays such as {mu}{yields}e{gamma}. We also comment on leptogenesis. The first scenario is disfavored on the level of one to two standard deviations, in particular, due to its prediction for |U{sub e3}|. There can be resonant leptogenesis with quasidegenerate heavy and light neutrinos, which would imply sizable cancellations in neutrinoless double beta decay. The decays {mu}{yields}e{gamma} and {tau}{yields}{mu}{gamma} are typically observable unless the SUSY masses approach the TeV scale. In the second scenario leptogenesis is impossible. It is, however, in perfect agreement with all oscillation data. The prediction for {mu}{yields}e{gamma} is in general too large, unless the SUSY masses are in the range of several TeV. In this case {tau}{yields}e{gamma} and {tau}{yields}{mu}{gamma} are unobservable.

  14. Restoration of parity and the right-handed analog of the CKM matrix

    NASA Astrophysics Data System (ADS)

    Senjanović, Goran; Tello, Vladimir

    2016-11-01

    In a recent article we determined analytically the right-handed quark mixing matrix in the minimal left-right symmetric theory with generalized parity. We derived its explicit form as a series expansion in a small parameter that measures the departure from Hermiticity of quark mass matrices. Here we analyze carefully the convergence of the series by including higher order terms and by comparing with numerical results. We apply our findings to some phenomenological applications such as the production and decays of the right-handed gauge boson WR, the neutrinoless double beta decay, the decays of the heavy scalar doublet, the strong C P parameter, and the theoretical limits on the new mass scale from the K - and B -meson physics. In particular, we demonstrate that the relevant coupling for the production of the WR gauge boson at hadronic colliders and for the neutrinoless double beta decay equals its left-handed counterpart, within a percent. We also demonstrate that the stability of the theoretical lower limit on the WR mass from the K -meson physics is due to a partial cancellation of the external phases of the right-handed mixing matrix.

  15. Measurement of ortho-positronium properties in liquid scintillators

    NASA Astrophysics Data System (ADS)

    Perasso, S.; Consolati, G.; Franco, D.; Jollet, C.; Meregaglia, A.; Tonazzo, A.; Yeh, M.

    2014-03-01

    Pulse shape discrimination is a well-established technique for background rejection in liquid scintillator detectors. It is particularly effective in separating heavy particles from light particles, but not in distinguishing electrons from positrons. This inefficiency can be overtaken by exploiting the formation of ortho-positronium (o-Ps), which alters the time profile of light pulses induced by positrons. We characterized the o-Ps properties in the most commonly used liquid scintillators, i.e. PC, PXE, LAB, OIL and PC + PPO. In addition, we studied the effects of scintillator doping on the o-Ps properties for dopants used in neutrino-less double beta decay experiments (Nd and Te) and in anti-neutrino and neutron detection (Gd and Li respectively). We found that the o-Ps properties are similar in all the tested scintillators, with a lifetime around 3 ns and a formation probability of about 50%. This result indicates that an o-Ps-enhanced pulse shape discrimination can be applied in liquid scintillator detectors for neutrino and anti-neutrino detection and for neutrino-less double beta decay search.

  16. Enriched TeO2 bolometers with active particle discrimination: Towards the CUPID experiment

    NASA Astrophysics Data System (ADS)

    Artusa, D. R.; Avignone, F. T.; Beeman, J. W.; Dafinei, I.; Dumoulin, L.; Ge, Z.; Giuliani, A.; Gotti, C.; de Marcillac, P.; Marnieros, S.; Nagorny, S.; Nisi, S.; Nones, C.; Norman, E. B.; Novati, V.; Olivieri, E.; Orlandi, D.; Pagnanini, L.; Pattavina, L.; Pessina, G.; Pirro, S.; Poda, D. V.; Rusconi, C.; Schäffner, K.; Scielzo, N. D.; Zhu, Y.

    2017-04-01

    We present the performances of two 92% enriched 130TeO2 crystals operated as thermal bolometers in view of a next generation experiment to search for neutrinoless double beta decay of 130Te. The crystals, 435 g each, show an energy resolution, evaluated at the 2615 keV γ-line of 208Tl, of 6.5 and 4.3 keV FWHM. The only observable internal radioactive contamination arises from 238U (15 and 8 μBq/kg, respectively). The internal activity of the most problematic nuclei for neutrinoless double beta decay, 226Ra and 228Th, are both evaluated as <3.1 μBq/kg for one crystal and <2.3 μBq/kg for the second. Thanks to the readout of the weak Cherenkov light emitted by β / γ particles by means of Neganov-Luke bolometric light detectors we were able to perform an event-by-event identification of β / γ events with a 95% acceptance level, while establishing a rejection factor of 98.21% and 99.99% for α particles.

  17. Feasibility study of SiGHT: a novel ultra low background photosensor for low temperature operation

    NASA Astrophysics Data System (ADS)

    Wang, Y.; Fan, A.; Fiorillo, G.; Galbiati, C.; Guan, M. Y.; Korga, G.; Pantic, E.; Razeto, A.; Renshaw, A.; Rossi, B.; Suvorov, Y.; Wang, H.; Yang, C. G.

    2017-02-01

    Rare event search experiments, such as those searching for dark matter and observations of neutrinoless double beta decay, require ultra low levels of radioactive background for unmistakable identification. In order to reduce the radioactive background of detectors used in these types of event searches, low background photosensors are required, as the physical size of these detectors become increasing larger, and hence the number of such photosensors used also increases rapidly. Considering that most dark matter and neutrinoless double beta decay experiments are turning towards using noble liquids as the target choice, liquid xenon and liquid argon for instance, photosensors that can work well at cryogenic temperatures are required, 165 K and 87 K for liquid xenon and liquid argon, respectively. The Silicon Geiger Hybrid Tube (SiGHT) is a novel photosensor designed specifically for use in ultra low background experiments operating at cryogenic temperatures. It is based on the proven photocathode plus silicon photomultiplier (SiPM) hybrid technology and consists of very few other, but also ultra radio-pure, materials like fused silica and silicon for the SiPM. The introduction of the SiGHT concept, as well as a feasibility study for its production, is reported in this paper.

  18. μ--e+ conversion from short-range operators

    NASA Astrophysics Data System (ADS)

    Geib, Tanja; Merle, Alexander

    2017-03-01

    We present a detailed discussion of the lepton flavor and number violating conversion of bound muons into positrons. This process is a viable alternative to neutrinoless double beta decay, and, given that experiments on ordinary μ-- e- conversion are expected to improve their sensitivities by several orders of magnitude in the coming years, we can also assume the limit on μ-- e+ conversion to improve by roughly the same factor. We discuss how new physics at a high scale can lead to short-range contributions to this conversion process, and we present one explicit case in great detail (the single one for which the corresponding nuclear matrix element is presently known). The main goal of our discussion is to make the respective computation accessible to the particle physics community, so that promising models can be investigated while the nuclear physics community can simultaneously advance the computation of nuclear matrix elements. Given the progress to be expected on the experimental side, it may even be possible that lepton number violation in the e μ -sector is discovered by μ-- e+ conversion before neutrinoless double beta decay can show its existence in the e e -sector.

  19. Theoretical study of neutrino scattering off the stable even Mo isotopes at low and intermediate energies

    NASA Astrophysics Data System (ADS)

    Balasi, K. G.; Ydrefors, E.; Kosmas, T. S.

    2011-10-01

    A systematic study of the cross sections of neutral-current neutrino scattering off the stable even Mo isotopes (mass number A=92,94,96,98,100), at low and intermediate neutrino energies ( E⩽130 MeV), is presented and discussed. The required wave functions for the initial (ground state) and all accessible final nuclear states are constructed in the context of the quasi-particle random-phase approximation (QRPA) and tested against data on the low-lying energy spectra of the isotopes in question. The individual contributions coming from the polar-vector and axial-vector components of the hadronic current for the coherent and incoherent channels of each isotope are investigated. The studied Mo isotopes are contents of the detector of the MOON experiment operating at Japan with a hybrid aim to search for neutrinoless double beta decay events and to detect low- and intermediate-energy astrophysical neutrinos (solar, supernova, geo-neutrinos), and also of the NEMO neutrinoless double beta decay detector in Modane at France. For such purposes our cross section calculations are of significant importance.

  20. Status of EXO-200

    SciTech Connect

    Ackerman, Nicole; /SLAC

    2011-12-06

    EXO-200 is the first phase of the Enriched Xenon Observatory (EXO) experiment, which searches for neutrinoless double beta decay in {sup 136}Xe to measure the mass and probe the Majorana nature of the neutrino. EXO-200 consists of 200 kg of liquid Xe enriched to 80% in {sup 136}Xe in an ultra-low background TPC. Energy resolution is enhanced through the simultaneous collection of scintillation light using Large Area Avalanche Photodiodes (LAAPD's) and ionization charge. It is being installed at the WIPP site in New Mexico, which provides a 2000 meter water-equivalent overburden. EXO-200 will begin taking data in 2009, with the expected two-year sensitivity to the half-life for neutrinoless double beta decay of 6.4 x 10{sup 25} years. According to the most recent nuclear matrix element calculations, this corresponds to an effective Majorana neutrino mass of 0.13 to 0.19 eV. It will also measure the two neutrino mode for the first time in {sup 136}Xe.

  1. Search for Low-Energy Events with CUORE-0 and CUORE

    NASA Astrophysics Data System (ADS)

    Lim, Kyungeun; Cuore Collaboration

    2015-10-01

    CUORE-0 is a cryogenic detector that uses an array of tellurium dioxide bolometers with the primary physics goal of searching for neutrinoless double-beta decay of 130Te. The detector consists of 52 natTeO2 crystal bolometers, which amounts to a total 130Te mass of 11kg, held in a ultra-pure copper frame. It was assembled using new low-background techniques developed for CUORE. The first results on the search for neutrinoless double-beta decay with CUORE-0 combined with Cuoricinio, a predecessor to CUORE-0, set the most stringent limit on the half-life of 130Te. Successful background mitigation, along with continuous data acquisition make CUORE-0 also suitable for other low-energy, rare event searches such as dark matter. I will discuss the status of the low-energy event search with CUORE-0 and prospects for CUORE. CUORE is in the final stages of construction and scheduled to begin data-taking in late 2015.

  2. Search for 0ν2β of {sup 100}Mo by NEMO-3 and status of SuperNEMO

    SciTech Connect

    Bongrand, Mathieu

    2015-07-15

    The NEMO-3 experiment was devoted to the research of the neutrinoless double beta decay and the precise measurement of the two-neutrino double beta decay of seven isotopes. The detector took data in the Laboratoire Souterrain de Modane (LSM) from 2003 to 2011. The unique combination of a 3D-tracker and a calorimeter allowed to fully reconstruct the double beta decay events topology and strongly reduces the backgrounds. This feature also permitted to characterize the remaining backgrounds in independent analysis channels. With an exposure of 34.7 kg·y of {sup 100}Mo no evidence for the 0ν2β signal has been found, yielding a limit for the light Majorana neutrino mass mechanism of T{sub 1/2}(0ν2β) > 1.1 10{sup 24} years (90 % C.L.) once both statistical and systematic uncertainties are taken into account. Depending on the Nuclear Matrix Elements this corresponds to an upper limit on the Majorana effective neutrino mass of |m{sub ββ}| < 0.3 − 0.9 eV (90 % C.L.). Constraints on other lepton number violating mechanisms of 0ν2β decays are also given. Searching for high-energy double electron events in all suitable sources of the detector, no event in the energy region [3.2-10] MeV is observed for an exposure of 47 kg·y. The next generation experiment, SuperNEMO, will use the same experimental technique to extend the sensitivity on the neutrinoless double beta decay search. Several aspects have been improved compared to NEMO-3: choice of the isotope, energy resolution, energy losses… but the main challenge is the background reduction. All the detector materials have been selected for their low natural radioactivity contaminations through High Purity Germanium (HPGe) gamma spectroscopy. The double beta sources after enrichment are being prepared with extreme care and the ultimate contaminations will be characterized by the most sensitive BiPo detector. External radon tightness and internal radon emanation have been studied to ensure a very low level in the

  3. Background reduction in the SNO+ experiment

    SciTech Connect

    Segui, L.

    2015-08-17

    SNO+ is a large multi-purpose liquid scintillator experiment, which first aim is to detect the neutrinoless double beta decay of {sup 130}Te. It is placed at SNOLAB, at 6000 m.w.e. and it is based on the SNO infrastructure. SNO+ will contain approximately 780 tonnes of liquid scintillator, loaded with {sup 130}Te inside an acrylic vessel (AV) with an external volume of ultra pure water to reduce the external backgrounds. Light produced in the scintillator by the interaction of particles will be detected with about 9,000 photomultiplier’s. For the neutrinoless double beta decay phase, due to its the extremely low rate expected, the control, knowledge and reduction of the background is essential. Moreover, it will also benefit other phases of the experiment focused on the study of solar neutrinos, nucleon decay, geoneutrinos and supernovae. In order to reduce the internal background level, a novel purification technique for tellurium loaded scintillators has been developed by the collaboration that reduces the U/Th concentration and several cosmic-activated isotopes by at least a factor 10{sup 2} -10{sup 3} in a single pass. In addition, different rejection techniques have been developed for the remaining internal backgrounds based on Monte-Carlo simulations. In this work, the scintillator purification technique and the levels obtained with it will be discussed. Furthermore, an overview of the different backgrounds for the double-beta phase will be presented, highlighting some of the techniques developed to reject the remained decays based on their expected timing differences.

  4. Investigation of double beta decay of {sup 116}Cd with the help of enriched {sup 116}CdWO{sub 4} crystal scintillators

    SciTech Connect

    Polischuk, O. G. Tretyak, V. I.; Barabash, A. S.; Konovalov, S. I.; Umatov, V. I.; Belli, P.; Bernabei, R.; D’Angelo, S.; Cappella, F.; Caracciolo, V.; Cerulli, R.; Laubenstein, M.; Chernyak, D. M.; Danevich, F. A.; Kobychev, V. V.; Mokina, V. M.; Incicchitti, A.; Poda, D. V.; Shlegel, V. N.; Vasiliev, Ya. V.

    2015-10-28

    An experiment to search for 2β processes in {sup 116}Cd with the help of enriched (to 82%) cadmium tungstate crystal scintillators is in progress at the Gran Sasso National Laboratory of the INFN (LNGS, Italy). After 11074 h of data taking in the last configuration, the preliminary estimate for the half-life of 116Cd relatively to 2ν2β decay is T{sub 1/2} = [2.52 ± 0.02(stat.) ± 0.14(syst.)] × 10{sup 19} yr. By using the data of previous stages of the experiment with a similar level of background (≈ 0.1 counts/(keV kg yr) in the energy interval 2.7 – 2.9 MeV; the total time of measurements is 19770 h) we have obtained a new limit on the 0ν2β decay of {sup 116}Cd to the ground state of {sup 116}Sn: T{sub 1/2} ≥ 1.9 × 10{sup 23} yr at 90% C.L. New limits on different 2β processes in {sup 116}Cd (decays with majorons, transitions to the excited levels) are obtained on the level of T{sub 1/2} ≥ 10{sup 20} – 10{sup 22} yr.

  5. Markov random fields reveal an N-terminal double beta-propeller motif as part of a bacterial hybrid two-component sensor system

    PubMed Central

    Menke, Matt; Berger, Bonnie; Cowen, Lenore

    2010-01-01

    The recent explosion in newly sequenced bacterial genomes is outpacing the capacity of researchers to try to assign functional annotation to all the new proteins. Hence, computational methods that can help predict structural motifs provide increasingly important clues in helping to determine how these proteins might function. We introduce a Markov Random Field approach tailored for recognizing proteins that fold into mainly β-structural motifs, and apply it to build recognizers for the β-propeller shapes. As an application, we identify a potential class of hybrid two-component sensor proteins, that we predict contain a double-propeller domain. PMID:20147619

  6. A search for the double-beta decay of Xenon-136 to an excited state of Barium-136 with exo-200

    NASA Astrophysics Data System (ADS)

    Yee, Shannon Koa

    While greater than 80% of all electricity continues to be generated by heat engines, methods of directly converting heat into electricity will remain appealing. Thermoelectric generators are one technology that is capable of doing this but the low efficiency and high cost has limited their terrestrial deployment. Thermoelectrics are compact, solid state devices, without moving parts that directly convert a temperature difference into a voltage. Developing better thermoelectric materials is challenging and requires that materials be engineered with new transport physics. The interface between organic and inorganic materials is one example where new transport physics manifests. Therefore, it is possible that improvements in thermoelectrics can be made by engineering organic-inorganic hybrid thermoelectric materials. Composite materials exhibit characteristics of their constituents where hybrid materials possess new properties that are distinctly different from their constituents. At the interface between organic and inorganic materials, hybrid properties manifest. One ideal system to understand this interface is in a metal-molecule-metal junction commonly referred to as a molecular junction. This is often a result of the discrete electronic energy levels of the organic hybridizing with the continuum of electronic states in the inorganic. Herein, new transport phenomenon is observed in molecular junctions, which have great promise for thermoelectrics. It is observed that the transport property are positively correlated breaking the historic trends to improving thermoelectric efficiency. Towards the goal of higher efficiency thermoelectrics, the fundamental science of interfaces is first investigated in molecular junctions. Guiding principles from these fundamental studies are then applied to engineer a bulk, polymer-based, thermoelectric materials with high efficiency. These improvements are encouraging and motivated a cost analysis to evaluate their current market potential against competing thermoelectric materials. In all, this dissertation marks the progress in developing a new class of hybrid organic-inorganic materials for thermoelectric applications.

  7. Thin Film Electrodes for Rare Event Detectors

    NASA Astrophysics Data System (ADS)

    Odgers, Kelly; Brown, Ethan; Lewis, Kim; Giordano, Mike; Freedberg, Jennifer

    2017-01-01

    In detectors for rare physics processes, such as neutrinoless double beta decay and dark matter, high sensitivity requires careful reduction of backgrounds due to radioimpurities in detector components. Ultra pure cylindrical resistors are being created through thin film depositions onto high purity substrates, such as quartz glass or sapphire. By using ultra clean materials and depositing very small quantities in the films, low radioactivity electrodes are produced. A new characterization process for cylindrical film resistors has been developed through analytic construction of an analogue to the Van Der Pauw technique commonly used for determining sheet resistance on a planar sample. This technique has been used to characterize high purity cylindrical resistors ranging from several ohms to several tera-ohms for applications in rare event detectors. The technique and results of cylindrical thin film resistor characterization will be presented.

  8. Results from KamLAND-Zen

    DOE PAGES

    Asakura, K.; Gando, A.; Gando, Y.; ...

    2015-07-15

    KamLAND-Zen reports on a preliminary search for neutrinoless double-beta decay with 136Xe based on 114.8 live-days after the purification of the xenon loaded liquid scintillator. In this data, the problematic 110mAg background peak identified in previous searches is reduced by more than a factor of 10. By combining the KamLAND-Zen pre- and post-purification data, we obtain a preliminary lower limit on the 0νββ decay half-life of T0ν1/2 > 2.6×1025 yr at 90% C.L. The search sensitivity will be enhanced with additional low background data after the purification. As a result, prospects for further improvements with future KamLAND-Zen upgrades are alsomore » presented.« less

  9. Results from KamLAND-Zen

    SciTech Connect

    Asakura, K.; Gando, A.; Gando, Y.; Hachiya, T.; Hayashida, S.; Ikeda, H.; Inoue, K.; Ishidoshiro, K.; Ishikawa, T.; Ishio, S.; Koga, M.; Matsuda, R.; Matsuda, S.; Mitsui, T.; Motoki, D.; Nakamura, K.; Obara, S.; Oki, Y.; Otani, M.; Oura, T.; Shimizu, I.; Shirahata, Y.; Shirai, J.; Suzuki, A.; Tachibana, H.; Tamae, K.; Ueshima, K.; Watanabe, H.; Xu, B. D.; Yamauchi, Y.; Yoshida, H.; Kozlov, A.; Takemoto, Y.; Yoshido, S.; Fushimi, K.; Banks, T. I.; Freedman, S. J.; Fujikawa, B. K.; O'Donnell, T.; Winslow, L. A.; Berger, B. E.; Efremenko, Y.; Karwowski, H. J.; Markoff, D. M.; Tornow, W.; Detwiler, J. A.; Enomoto, S.; Decowski, M. P.

    2015-07-15

    KamLAND-Zen reports on a preliminary search for neutrinoless double-beta decay with 136Xe based on 114.8 live-days after the purification of the xenon loaded liquid scintillator. In this data, the problematic 110mAg background peak identified in previous searches is reduced by more than a factor of 10. By combining the KamLAND-Zen pre- and post-purification data, we obtain a preliminary lower limit on the 0νββ decay half-life of T1/2 > 2.6×1025 yr at 90% C.L. The search sensitivity will be enhanced with additional low background data after the purification. As a result, prospects for further improvements with future KamLAND-Zen upgrades are also presented.

  10. The Sanford Underground Research Facility at Homestake (SURF)

    NASA Astrophysics Data System (ADS)

    Lesko, K. T.

    The former Homestake gold mine in Lead, South Dakota is being transformed into a dedicated laboratory to pursue underground research in rare-process physics, as well as offering research opportunities in other disciplines. A key component of the Sanford Underground Research Facility (SURF) is the Davis Campus, which is in operation at the 4850-foot level (4300 m.w.e) and currently hosts three projects: the LUX dark matter experiment, the MAJORANA DEMONSTRATOR neutrinoless double-beta decay experiment and the Berkeley and CUBED low-background counters. Plans for possible future experiments at SURF are well underway and include long baseline neutrino oscillation experiments, future dark matter experiments as well as nuclear astrophysics accelerators. Facility upgrades to accommodate some of these future projects have already started. SURF is a dedicated facility with significant expansion capability. These plans include a Generation-2 Dark Matter experiment and the US flagship neutrino experiment, LBNE.

  11. Mu-tau reflection symmetry with a texture-zero

    NASA Astrophysics Data System (ADS)

    Nishi, C. C.; Sánchez-Vega, B. L.

    2017-01-01

    The μτ-reflection symmetry is a simple symmetry capable of predicting all the unknown CP phases of the lepton sector and the atmospheric angle but too simple to predict the absolute neutrino mass scale or the mass ordering. We show that by combining it with a discrete abelian symmetry in a nontrivial way we can additionally enforce a texture-zero and obtain a highly predictive scenario where the lightest neutrino mass is fixed to be in the few meV range for two normal ordering (NO) solutions or in the tens of meV in one inverted ordering (IO) solution. The rate for neutrinoless double beta decay is predicted to be negligible for NO or have effective mass m ββ ≈ 14-29 meV for IO, right in the region to be probed in future experiments.

  12. Feshbach Prize: New Phenomena and New Physics from Strongly-Correlated Quantum Matter

    NASA Astrophysics Data System (ADS)

    Carlson, Joseph A.

    2017-01-01

    Strongly correlated quantum matter is ubiquitous in physics from cold atoms to nuclei to the cold dense matter found in neutron stars. Experiments from table-top to the extremely large scale experiments including FRIB and LIGO will help determine the properties of matter across an incredible scale of distances and energies. Questions to be addressed include the existence of exotic states of matter in cold atoms and nuclei, the response of this correlated matter to external probes, and the behavior of matter in extreme astrophysical environments. A more complete understanding is required, both to understand these diverse phenomena and to employ this understanding to probe for new underlying physics in experiments including neutrinoless double beta decay and accelerator neutrino experiments. I will summarize some aspects of our present understanding and highlight several important prospects for the future.

  13. Analysis techniques for background rejection at the MAJORANA DEMONSTRATOR

    SciTech Connect

    Cuesta, C; Abgrall, N.; Arnquist, I. J.; Avignone, III, F. T.; Barabash, A.S.; Bertrand, F. E.; Bradley, A. W.; Brudanin, V.; Busch, M.; Byram, D.; Caldwell, A. S.; Chan, Y-D; Christofferson, C. D.; Detwiler, J. A.; Efremenko, Yu.; Ejiri, H.; Elliott, S. R.; Galindo-Uribarri, A.; Gilliss, T.; Green, M. P.; Gruszko, J; Guinn, I S; Guiseppe, V E; Henning, R.; Howard, S.; Howe, M. A.; Keeter, K.J.; Kidd, M. F.; Konovalov, S.I.; Kouzes, R. T.; LaFerriere, B. D.; Leon, J.; MacMullin, J.; Meijer, S. J.; Orrell, J. L.; O'Shaughnessy, C.; Radford, D. C.; Rager, J.; Robertson, R.G.H.; Romero-Romero, E.; Snyder, N; Suriano, A. M.; Tedeschi, D; Trimble, J. E.; Vasilyev, S.; Vetter, K. [University of California et al.

    2015-01-01

    The MAJORANA Collaboration is constructing the MAJORANA DEMONSTRATOR, an ultra-low background, 40-kg modular HPGe detector array to search for neutrinoless double beta decay in Ge-76. In view of the next generation of tonne-scale Ge-based 0 nu beta beta-decay searches that will probe the neutrino mass scale in the inverted-hierarchy region, a major goal of the MAJORANA DEMONSTRATOR is to demonstrate a path forward to achieving a background rate at or below 1 count/tonne/year in the 4 keV region of interest around the Q-value at 2039 keV. The background rejection techniques to be applied to the data include cuts based on data reduction, pulse shape analysis, event coincidences, and time correlations. The Point Contact design of the DEMONSTRATOR's germanium detectors allows for significant reduction of gamma background.

  14. Development of a Li2MoO4 scintillating bolometer for low background physics

    NASA Astrophysics Data System (ADS)

    Cardani, L.; Casali, N.; Nagorny, S.; Pattavina, L.; Piperno, G.; Barinova, O. P.; Beeman, J. W.; Bellini, F.; Danevich, F. A.; Di Domizio, S.; Gironi, L.; Kirsanova, S. V.; Orio, F.; Pessina, G.; Pirro, S.; Rusconi, C.; Tomei, C.; Tretyak, V. I.; Vignati, M.

    2013-10-01

    We present the performance of a 33 g Li2MoO4 crystal working as a scintillating bolometer. The crystal was tested for more than 400 h in a dilution refrigerator installed in the underground laboratory of Laboratori Nazionali del Gran Sasso (Italy). This compound shows promising features in the frame of neutron detection, dark matter search (solar axions) and neutrinoless double-beta decay physics. Low temperature scintillating properties were investigated by means of different α, β/γ and neutron sources, and for the first time the Light Yield for different types of interacting particle is estimated. The detector shows great ability of tagging fast neutron interactions and high intrinsic radiopurity levels ( < 90 μBq/kg for 238U and < 110 μBq/kg for 232Th).

  15. Physics of rare events: insights on Napoleon death

    NASA Astrophysics Data System (ADS)

    Fiorini, Ettore

    2009-03-01

    This unusual report tries to show that the high level of sophistication reached in the instrumentation in experiments on rare events can allow to investigate with unprecedented accuracy problems far from those of fundamental physics, but quite important in other fields of physics. The technique and the know-how on neutron activation developed to reduce the background due to spurious events in the CUORE detector to search for neutrinoless double beta decay has been applied to determine the arsenic contents in the hairs of Napoleon Bonaparte and of historical subjects of his time and to compare it with those of subjects living presently. This contents has been found to be about two orders of magnitude larger than the present ones. The As concentration in the hairs of the Emperor is large, but similar to those of the his contemporaries. In additions a comparison among fraction of one of his hairs allows to exclude a criminal act.

  16. Recommendations for a Static Cosmic Ray Shield for Enriched Germanium Detectors

    SciTech Connect

    Aguayo Navarrete, Estanislao; Orrell, John L.; Ankney, Austin S.; Berguson, Timothy J.

    2011-09-21

    This document provides a detailed study of cost and materials that could be used to shield the detector material of the international Tonne-scale germanium neutrinoless double-beta decay experiment from hadronic particles from cosmic ray showers at the Earth's surface. This work was motivated by the need for a shield that minimizes activation of the enriched germanium during storage; in particular, when the detector material is being worked on at the detector manufacturer's facility. This work considers two options for shielding the detector material from cosmic ray particles. One option is to use a pre-existing structure already located near the detector manufacturer, such as Canberra Industries in Meriden, Connecticut. The other option is to build a shield onsite at a detector manufacturer's site. This paper presents a cost and efficiency analysis of such construction.

  17. Testing the Ge detectors for the MAJORANA DEMONSTRATOR

    DOE PAGES

    Xu, W.; Abgrall, N.; Aguayo, E.; ...

    2015-03-24

    High purity germanium (HPGe) crystals will be used for the MAJORANA DEMONSTRATOR, where they serve as both the source and the detector for neutrinoless double beta decay. It is crucial for the experiment to understand the performance of the HPGe crystals. A variety of crystal properties are being investigated, including basic properties such as energy resolution, efficiency, uniformity, capacitance, leakage current and crystal axis orientation, as well as more sophisticated properties, e.g. pulse shapes and dead layer and transition layer distributions. In this talk, we will present our measurements that characterize the HPGe crystals. We will also discuss the ourmore » simulation package for the detector characterization setup, and show that additional information can be extracted from data-simulation comparisons.« less

  18. Construction and measurements of a vacuum-swing-adsorption radon-mitigation system

    SciTech Connect

    Schnee, R. W.; Bunker, R.; Ghulam, G.; Jardin, D.; Kos, M.; Tenney, A. S.

    2013-08-08

    Long-lived alpha and beta emitters in the {sup 222}Rn decay chain on (and near) detector surfaces may be the limiting background in many experiments attempting to detect dark matter or neutrinoless double beta decay, and in screening detectors. In order to reduce backgrounds from radon-daughter plate-out onto the wires of the Beta Cage during its assembly, an ultra-low-radon cleanroom is being commissioned at Syracuse University using a vacuum-swing-adsorption radon-mitigation system. The radon filter shows ∼20× reduction at its output, from 7.47±0.56 to 0.37±0.12 Bq/m{sup 3}, and the cleanroom radon activity meets project requirements, with a lowest achieved value consistent with that of the filter, and levels consistently < 2 Bq/m{sup 3}.

  19. Radon induced surface contaminations in low background experiments

    SciTech Connect

    Pattavina, L.

    2013-08-08

    In neutrinoless double-beta decay and dark matter searches, one of the main issues is to increase the experimental sensitivity through careful material selection and production, minimizing the background contributions. In order to achieve the required, extremely low, counting rates, very stringent requirements must be fulfilled in terms of bulk material radiopurity. As the experimental sensitivity increases, the bulk impurities in the detector components decrease, and surface contaminations start to play an increasingly significant role In fully active detectors, like cryogenic particle detectors, surface contaminations are a critical issue (as shown by the CUORICINO experiment). {sup 222}Rn is by far the most intense source of airborne radioactivity, and if a radio-pure material is exposed to environment where the Radon concentration is not minimized, {sup 210}Pb and {sup 210}Po contaminations can occur. The mechanisms and the dynamics of Radon-induced surface contaminations are reviewed, and specific solutions to prevent and to reject the induced background are presented.

  20. Modeling surface backgrounds from radon progeny plate-out

    SciTech Connect

    Perumpilly, G.; Guiseppe, V. E.; Snyder, N.

    2013-08-08

    The next generation low-background detectors operating deep underground aim for unprecedented low levels of radioactive backgrounds. The surface deposition and subsequent implantation of radon progeny in detector materials will be a source of energetic background events. We investigate Monte Carlo and model-based simulations to understand the surface implantation profile of radon progeny. Depending on the material and region of interest of a rare event search, these partial energy depositions can be problematic. Motivated by the use of Ge crystals for the detection of neutrinoless double-beta decay, we wish to understand the detector response of surface backgrounds from radon progeny. We look at the simulation of surface decays using a validated implantation distribution based on nuclear recoils and a realistic surface texture. Results of the simulations and measured α spectra are presented.

  1. Studies on the reduction of radon plate-out

    SciTech Connect

    Bruemmer, M.; Nakib, M.; Calkins, R.; Cooley, J. Sekula, S.

    2015-08-17

    The decay of common radioactive gases, such as radon, produces stable isotopes by a sequence of daughter particles with varied half-lives. These daughter particles are a significant source of gamma, neutron, and alpha (α) particle backgrounds that can mimic desired signals in dark matter and neutrinoless double beta decay experiments. In the LUMINA Laboratory at Southern Methodist University (SMU), studies of radon plate-out onto copper samples are conducted using one of XIA’s first five UltraLo 1800 alpha counters. We present results from investigations into various mitigation approaches. A custom-built copper holder (in either plastic or metal) has been designed and produced to maximize the copper’s exposure to {sup 220}Rn. The {sup 220}Rn source is a collection of camping lantern mantles. We present the current status of control and experimental methods for addressing radon exposure levels.

  2. The Sanford Underground Research Facility at Homestake (SURF)

    SciTech Connect

    Lesko, K. T.

    2015-03-24

    The former Homestake gold mine in Lead, South Dakota is being transformed into a dedicated laboratory to pursue underground research in rare-process physics, as well as offering research opportunities in other disciplines. A key component of the Sanford Underground Research Facility (SURF) is the Davis Campus, which is in operation at the 4850-foot level (4300 m.w.e) and currently hosts three projects: the LUX dark matter experiment, the Majorana Demonstrator neutrinoless double-beta decay experiment and the Berkeley and CUBED low-background counters. Plans for possible future experiments at SURF are well underway and include long baseline neutrino oscillation experiments, future dark matter experiments as well as nuclear astrophysics accelerators. Facility upgrades to accommodate some of these future projects have already started. SURF is a dedicated facility with significant expansion capability. These plans include a Generation-2 Dark Matter experiment and the US flagship neutrino experiment, LBNE.

  3. Flavor democracy and type-II seesaw realization of bilarge neutrino mixing

    NASA Astrophysics Data System (ADS)

    Rodejohann, Werner; Xing, Zhi-Zhong

    2004-11-01

    We generalize the democratic neutrino mixing ansatz by incorporating the type-II seesaw mechanism with S(3) flavor symmetry. For only the triplet mass term or only the conventional seesaw term large neutrino mixing can be achieved only by assuming an unnatural suppression of the flavor democracy contribution. We show that bilarge neutrino mixing can naturally appear if the flavor democracy term is strongly suppressed due to significant cancellation between the conventional seesaw and triplet mass terms. Explicit S(3) symmetry breaking yields successful neutrino phenomenology and various testable correlations between the neutrino mass and mixing parameters. Among the results are a normal neutrino mass ordering, 0.005 ⩽ |Ue 3 | ⩽ 0.057, 1 -sin2 2θ23 ⩾ 0.005, positive JCP and moderate cancellation in the effective mass of the neutrinoless double beta decay.

  4. Energy resolution and efficiency of phonon-mediated kinetic inductance detectors for light detection

    NASA Astrophysics Data System (ADS)

    Cardani, L.; Colantoni, I.; Cruciani, A.; Di Domizio, S.; Vignati, M.; Bellini, F.; Casali, N.; Castellano, M. G.; Coppolecchia, A.; Cosmelli, C.; Tomei, C.

    2015-08-01

    The development of sensitive cryogenic light detectors is of primary interest for bolometric experiments searching for rare events like dark matter interactions or neutrino-less double beta decay. Thanks to their good energy resolution and the natural multiplexed read-out, Kinetic Inductance Detectors (KIDs) are particularly suitable for this purpose. To efficiently couple KIDs-based light detectors to the large crystals used by the most advanced bolometric detectors, active surfaces of several cm2 are needed. For this reason, we are developing phonon-mediated detectors. In this paper, we present the results obtained with a prototype consisting of four 40 nm thick aluminum resonators patterned on a 2 × 2 cm2 silicon chip, and calibrated with optical pulses and X-rays. The detector features a noise resolution σE = 154 ± 7 eV and an (18 ± 2)% efficiency.

  5. Bilinear R-parity violation with flavor symmetry

    NASA Astrophysics Data System (ADS)

    Bazzocchi, F.; Morisi, S.; Peinado, E.; Valle, J. W. F.; Vicente, A.

    2013-01-01

    Bilinear R-parity violation (BRPV) provides the simplest intrinsically super-symmetric neutrino mass generation scheme. While neutrino mixing parameters can be probed in high energy accelerators, they are unfortunately not predicted by the theory. Here we propose a model based on the discrete flavor symmetry A 4 with a single R-parity violating parameter, leading to (i) correct Cabbibo mixing given by the Gatto-Sartori-Tonin formula, and a successful unification-like b-tau mass relation, and (ii) a correlation between the lepton mixing angles θ 13 and θ 23 in agreement with recent neutrino oscillation data, as well as a (nearly) massless neutrino, leading to absence of neutrinoless double beta decay.

  6. Measurable neutrino mass scale in A{sub 4}xSU(5)

    SciTech Connect

    Antusch, S.; Spinrath, M.; King, Stephen F.

    2011-01-01

    We propose a supersymmetric A{sub 4}xSU(5) model of quasidegenerate neutrinos which predicts the effective neutrino mass m{sub ee} relevant for neutrinoless double beta decay to be proportional to the neutrino mass scale, thereby allowing its determination approximately independently of unknown Majorana phases. Such a natural quasidegeneracy is achieved by using A{sub 4} family symmetry (as an example of a non-Abelian family symmetry with real triplet representations) to enforce a contribution to the neutrino mass matrix proportional to the identity. Tribimaximal neutrino mixing as well as quark CP violation with {alpha}{approx_equal}90 deg. d a leptonic CP phase {delta}{sub MNS{approx_equal}}90 deg. arise from the breaking of the A{sub 4} family symmetry by the vacuum expectation values of four 'flavon' fields pointing in specific postulated directions in flavor space.

  7. Electron line shape and transmission function of the KATRIN monitor spectrometer

    SciTech Connect

    Slezák, M.

    2013-12-30

    Knowledge of the neutrino mass is of particular interest in modern neutrino physics. Besides the neutrinoless double beta decay and cosmological observation information about the neutrino mass is obtained from single beta decay by observing the shape of the electron spectrum near the endpoint. The KATRIN β decay experiment aims to push the limit on the effective electron antineutrino mass down to 0.2 eV/c{sup 2}. To reach this sensitivity several systematic effects have to be under control. One of them is the fluctuations of the absolute energy scale, which therefore has to be continuously monitored at very high precision. This paper shortly describes KATRIN, the technique for continuous monitoring of the absolute energy scale and recent improvements in analysis of the monitoring data.

  8. Light sterile neutrino and dark matter in left-right symmetric models without a Higgs bidoublet

    NASA Astrophysics Data System (ADS)

    Borah, Debasish

    2016-10-01

    We present a class of left-right symmetric models where Dirac as well as Majorana mass terms of neutrinos can arise at the one-loop level in a scotogenic fashion: with dark matter particles going inside the loop. We show the possibility of naturally light right-handed neutrinos that can have interesting implications for neutrinoless double beta decay experiments as well as cosmology. Apart from a stable dark matter candidate stabilized by a remnant Z2 symmetry, one can also have a long-lived keV sterile neutrino dark matter in these models. This class of models can have very different collider signatures compared to the conventional left-right models.

  9. A dark matter search with MALBEK

    DOE PAGES

    Giovanetti, G. K.; Abgrall, N.; Aguayo, E.; ...

    2015-01-01

    The Majorana Demonstrator is an array of natural and enriched high purity germanium detectors that will search for the neutrinoless double-beta decay of ⁷⁶Ge and perform a search for weakly interacting massive particles (WIMPs) with masses below 10 GeV. As part of the Majorana research and development efforts, we have deployed a modified, low-background broad energy germanium detector at the Kimballton Underground Research Facility. With its sub-keV energy threshold, this detector is sensitive to potential non-Standard Model physics, including interactions with WIMPs. We discuss the backgrounds present in the WIMP region of interest and explore the impact of slow surfacemore » event contamination when searching for a WIMP signal.« less

  10. Heavy-ion double charge exchange reactions: A tool toward 0 νββ nuclear matrix elements

    NASA Astrophysics Data System (ADS)

    Cappuzzello, F.; Cavallaro, M.; Agodi, C.; Bondì, M.; Carbone, D.; Cunsolo, A.; Foti, A.

    2015-11-01

    The knowledge of the nuclear matrix elements for the neutrinoless double beta decay is fundamental for neutrino physics. In this paper, an innovative technique to extract information on the nuclear matrix elements by measuring the cross section of a double charge exchange nuclear reaction is proposed. The basic point is that the initial- and final-state wave functions in the two processes are the same and the transition operators are similar. The double charge exchange cross sections can be factorized in a nuclear structure term containing the matrix elements and a nuclear reaction factor. First pioneering experimental results for the 40Ca(18O,18Ne)40Ar reaction at 270 MeV incident energy show that such cross section factorization reasonably holds for the crucial 0+ → 0+ transition to 40Args, at least at very forward angles.

  11. Unification of gauge, family, and flavor symmetries illustrated in gauged SU(12) models

    DOE PAGES

    Albright, Carl H.; Feger, Robert P.; Kephart, Thomas W.

    2016-04-25

    In this study, to explain quark and lepton masses and mixing angles, one has to extend the standard model, and the usual practice is to put the quarks and leptons into irreducible representations of discrete groups. We argue that discrete flavor symmetries (and their concomitant problems) can be avoided if we extend the gauge group. In the framework of SU(12) we give explicit examples of models having varying degrees of predictability obtained by scanning over groups and representations and identifying cases with operators contributing to mass and mixing matrices that need little fine- tuning of prefactors. Fitting with quark andmore » lepton masses run to the GUT scale and known mixing angles allows us to make predictions for the neutrino masses and hierarchy, the octant of the atmospheric mixing angle, leptonic CP violation, Majorana phases, and the effective mass observed in neutrinoless double beta decay.« less

  12. Optical properties of quantum-dot-doped liquid scintillators

    PubMed Central

    Aberle, C.; Li, J.J.; Weiss, S.; Winslow, L.

    2014-01-01

    Semiconductor nanoparticles (quantum dots) were studied in the context of liquid scintillator development for upcoming neutrino experiments. The unique optical and chemical properties of quantum dots are particularly promising for the use in neutrinoless double-beta decay experiments. Liquid scintillators for large scale neutrino detectors have to meet specific requirements which are reviewed, highlighting the peculiarities of quantum-dot-doping. In this paper, we report results on laboratory-scale measurements of the attenuation length and the fluorescence properties of three commercial quantum dot samples. The results include absorbance and emission stability measurements, improvement in transparency due to filtering of the quantum dot samples, precipitation tests to isolate the quantum dots from solution and energy transfer studies with quantum dots and the fluorophore PPO. PMID:25392711

  13. Search for Majorana neutrinos with the SNO+ detector at SNOLAB

    NASA Astrophysics Data System (ADS)

    Maio, A.; SNO+ Collaboration

    2015-02-01

    The SNO+ experiment is adapting the Sudbury Neutrino Observatory (SNO) detector, in order to use isotope-loaded liquid scintillator as the active medium. SNO+ has multiple scientific goals, the main one being the search for neutrinoless double beta decay, the most promising signature for the possible Majorana character of neutrinos and for the absolute neutrino mass. Measurements of neutrinos from the Sun, the Earth, Supernovae and nuclear reactors are additional goals of the experiment. The detector consists of a 12m diameter spherical vessel, filled with 780 tonnes of Tellurium-loaded liquid scintillator, and surrounded by about 9500 PMTs. It is shielded by a large volume of ultra-pure water and the underground location at SNOLAB, Canada. This talk will review the Physics goals and current status of SNO+.

  14. Sterile neutrinos and right-handed currents in KATRIN

    NASA Astrophysics Data System (ADS)

    Barry, James; Heeck, Julian; Rodejohann, Werner

    2014-07-01

    Kurie-plot experiments allow for neutrino-mass measurements based on kinematics in an almost model-independent manner. A future tritium-based KATRIN-like experiment can be sensitive to light sterile neutrinos with masses below 18 keV, which are among the prime candidates for warm dark matter. Here we consider such keV neutrinos in left-right symmetric extensions, i.e. coupled to right-handed currents, which allow for an enhanced contribution to beta decay even for small active-sterile mixing, without violating astrophysical X-ray constraints. The modified spectral shape is in principle distinguishable from the standard contribution — especially for sterile neutrino masses below 9 keV, which can lead to a distinct peak. We compare the sensitivity to constraints from the LHC and neutrinoless double beta decay.

  15. Reflectance of polytetrafluoroethylene for xenon scintillation light

    SciTech Connect

    Silva, C.; Pinto da Cunha, J.; Pereira, A.; Chepel, V.; Lopes, M. I.; Solovov, V.; Neves, F.

    2010-03-15

    Gaseous and liquid xenon particle detectors are being used in a number of applications including dark matter search and neutrino-less double beta decay experiments. Polytetrafluoroethylene (PTFE) is often used in these detectors both as electrical insulator and as a light reflector to improve the efficiency of detection of scintillation photons. However, xenon emits in the vacuum ultraviolet (VUV) wavelength region ({lambda}{approx_equal}175 nm) where the reflecting properties of PTFE are not sufficiently known. In this work, we report on measurements of PTFE reflectance, including its angular distribution, for the xenon scintillation light. Various samples of PTFE, manufactured by different processes (extruded, expanded, skived, and pressed) have been studied. The data were interpreted with a physical model comprising both specular and diffuse reflections. The reflectance obtained for these samples ranges from about 47% to 66% for VUV light. Other fluoropolymers, namely, ethylene tetrafluoroethylene (ETFE), fluorinated ethylene propylene (FEP), and perfluoro-alkoxyalkane (PFA) were also measured.

  16. The Majorana Parts Tracking Database

    SciTech Connect

    Abgrall, N.

    2015-01-16

    The Majorana Demonstrator is an ultra-low background physics experiment searching for the neutrinoless double beta decay of 76Ge. The Majorana Parts Tracking Database is used to record the history of components used in the construction of the Demonstrator. The tracking implementation takes a novel approach based on the schema-free database technology CouchDB. Transportation, storage, and processes undergone by parts such as machining or cleaning are linked to part records. Tracking parts provides a great logistics benefit and an important quality assurance reference during construction. In addition, the location history of parts provides an estimate of their exposure to cosmic radiation. In summary, a web application for data entry and a radiation exposure calculator have been developed as tools for achieving the extreme radio-purity required for this rare decay search.

  17. Background modeling for the GERDA experiment

    SciTech Connect

    Becerici-Schmidt, N.; Collaboration: GERDA Collaboration

    2013-08-08

    The neutrinoless double beta (0νββ) decay experiment GERDA at the LNGS of INFN has started physics data taking in November 2011. This paper presents an analysis aimed at understanding and modeling the observed background energy spectrum, which plays an essential role in searches for a rare signal like 0νββ decay. A very promising preliminary model has been obtained, with the systematic uncertainties still under study. Important information can be deduced from the model such as the expected background and its decomposition in the signal region. According to the model the main background contributions around Q{sub ββ} come from {sup 214}Bi, {sup 228}Th, {sup 42}K, {sup 60}Co and α emitting isotopes in the {sup 226}Ra decay chain, with a fraction depending on the assumed source positions.

  18. Investigation of radioactivity-induced backgrounds in EXO-200

    NASA Astrophysics Data System (ADS)

    Albert, J. B.; Auty, D. J.; Barbeau, P. S.; Beck, D.; Belov, V.; Benitez-Medina, C.; Breidenbach, M.; Brunner, T.; Burenkov, A.; Cao, G. F.; Chambers, C.; Cleveland, B.; Coon, M.; Craycraft, A.; Daniels, T.; Danilov, M.; Daugherty, S. J.; Davis, C. G.; Davis, J.; Delaquis, S.; Der Mesrobian-Kabakian, A.; DeVoe, R.; Didberidze, T.; Dolgolenko, A.; Dolinski, M. J.; Dunford, M.; Fairbank, W.; Farine, J.; Feldmeier, W.; Fierlinger, P.; Fudenberg, D.; Giroux, G.; Gornea, R.; Graham, K.; Gratta, G.; Hall, C.; Herrin, S.; Hughes, M.; Jewell, M. J.; Jiang, X. S.; Johnson, A.; Johnson, T. N.; Johnston, S.; Karelin, A.; Kaufman, L. J.; Killick, R.; Koffas, T.; Kravitz, S.; Kuchenkov, A.; Kumar, K. S.; Leonard, D. S.; Licciardi, C.; Lin, Y. H.; Ling, J.; MacLellan, R.; Marino, M. G.; Mong, B.; Moore, D.; Nelson, R.; Odian, A.; Ostrovskiy, I.; Piepke, A.; Pocar, A.; Prescott, C. Y.; Rivas, A.; Rowson, P. C.; Russell, J. J.; Schubert, A.; Sinclair, D.; Smith, E.; Stekhanov, V.; Tarka, M.; Tolba, T.; Tsang, R.; Twelker, K.; Vuilleumier, J.-L.; Waite, A.; Walton, J.; Walton, T.; Weber, M.; Wen, L. J.; Wichoski, U.; Wood, J.; Yang, L.; Yen, Y.-R.; Zeldovich, O. Ya.; EXO-200 Collaboration

    2015-07-01

    The search for neutrinoless double-beta decay (0 ν β β ) requires extremely low background and a good understanding of their sources and their influence on the rate in the region of parameter space relevant to the 0 ν β β signal. We report on studies of various β and γ backgrounds in the liquid-xenon-based EXO-200 0 ν β β experiment. With this work we try to better understand the location and strength of specific background sources and compare the conclusions to radioassay results taken before and during detector construction. Finally, we discuss the implications of these studies for EXO-200 as well as for the next-generation, tonne-scale nEXO detector.

  19. Geometry of the effective Majorana neutrino mass in the 0νββ decay

    NASA Astrophysics Data System (ADS)

    Xing, Zhi-zhong; Zhou, Ye-Ling

    2015-01-01

    The neutrinoless double-beta (0νββ) decay is a unique process used to identify the Majorana nature of massive neutrinos, and its rate depends on the size of the effective Majorana neutrino mass ee. We put forward a novel ‘coupling-rod’ diagram to describe ee in the complex plane, by which the effects of the neutrino mass ordering and CP-violating phases on ee are intuitively understood. We show that this geometric language allows us to easily obtain the maximum and minimum of |ee|. It remains usable even if there is a kind of new physics contributing to ee, and it can also be extended to describe the effective Majorana masses eμ, eτ, μτ and ττ which may appear in some other lepton-number violating processes.

  20. Cal Poly Contributions to the CUORE Experiment

    NASA Astrophysics Data System (ADS)

    Miller, David; Meijer, Samuel; Haskin, Michael; Gutierrez, Thomas

    2012-11-01

    CUORE (Cryogenic Underground Observatory for Rare Events) is a multinational experimental collaboration searching for the lepton-violating neutrinoless double beta decay (0νββ) in ^130Te. The detection of 0νββ would indicate the neutrino is a Majorana fermion and also set the absolute mass scale of the electron neutrino. The experiment is currently being built in stages at the Gran Sasso National Laboratory in Assergi, Italy. CUORE-0 is a detector array expected to go online this year consisting of 52 bolometric crystals in a single tower, which is equivalent to 1/19th of the full mass of CUORE. We will describe our recent contributions to activities associated with CUORE-0 deployment, background reduction efforts, and the CUORE crystal verification runs as the collaboration works towards bringing CUORE online in 2014.

  1. Removal of long-lived 222Rn daughters by electropolishing thin layers of stainless steel

    NASA Astrophysics Data System (ADS)

    Schnee, R. W.; Bowles, M. A.; Bunker, R.; McCabe, K.; White, J.; Cushman, P.; Pepin, M.; Guiseppe, V. E.

    2013-08-01

    Long-lived alpha and beta emitters in the 222Rn decay chain on detector surfaces may be the limiting background in many experiments attempting to detect dark matter or neutrinoless double beta decay. Removal of tens of microns of material via electropolishing has been shown to be effective at removing radon daughters implanted into material surfaces. Some applications, however, require the removal of uniform and significantly smaller thicknesses. Here, we demonstrate that electropolishing < 1 μm from stainless-steel plates reduces the contamination efficiently, by a factor > 100. Examination of electropolished wires with a scanning electron microscope confirms that the thickness removed is reproducible and reasonably uniform. Together, these tests demonstrate the effectiveness of removal of radon daughters for a proposed low-radiation, multi-wire proportional chamber (the BetaCage), without compromising the screener's energy resolution. More generally, electropolishing thin layers of stainless steel may effectively remove radon daughters without compromising precision-machined parts.

  2. A dark matter search with MALBEK

    SciTech Connect

    Giovanetti, G. K.; Abgrall, N.; Aguayo, E.; Avignone, III, F. T.; Barabash, A. S.; Bertrand, F. E.; Boswell, M.; Brudanin, V.; Busch, M.; Byram, D.; Caldwell, A. S.; Chan, Y. -D.; Christofferson, C. D.; Combs, D. C.; Cuesta, C.; Detwiler, J. A.; Doe, P. J.; Efremenko, Yu.; Egorov, V.; Ejiri, H.; Elliott, S. R.; Fast, J. E.; Finnerty, P.; Fraenkle, F. M.; Galindo-Uribarri, A.; Goett, J.; Green, M. P.; Gruszko, J.; Guiseppe, V. E.; Gusev, K.; Hallin, A. L.; Hazama, R.; Hegai, A.; Henning, R.; Hoppe, E. W.; Howard, S.; Howe, M. A.; Keeter, K. J.; Kidd, M. F.; Kochetov, O.; Konovalov, S. I.; Kouzes, R. T.; LaFerriere, B. D.; Leon, J.; Leviner, L. E.; Loach, J. C.; MacMullin, J.; MacMullin, S.; Martin, R. D.; Meijer, S.; Mertens, S.; Nomachi, M.; Orrell, J. L.; O'Shaughnessy, C.; Overman, N. R.; Phillips, II, D. G.; Poon, A. W.P.; Pushkin, K.; Radford, D. C.; Rager, J.; Rielage, K.; Robertson, R. G.H.; Romero-Romero, E.; Ronquest, M. C.; Schubert, A. G.; Shanks, B.; Shima, T.; Shirchenko, M.; Snavely, K. J.; Snyder, N.; Suriano, A. M.; Thompson, J.; Timkin, V.; Tornow, W.; Trimble, J. E.; Varner, R. L.; Vasilyev, S.; Vetter, K.; Vorren, K.; White, B. R.; Wilkerson, J. F.; Wiseman, C.; Xu, W.; Yakushev, E.; Young, A. R.; Yu, C. -H.; Yumatov, V.

    2015-01-01

    The Majorana Demonstrator is an array of natural and enriched high purity germanium detectors that will search for the neutrinoless double-beta decay of ⁷⁶Ge and perform a search for weakly interacting massive particles (WIMPs) with masses below 10 GeV. As part of the Majorana research and development efforts, we have deployed a modified, low-background broad energy germanium detector at the Kimballton Underground Research Facility. With its sub-keV energy threshold, this detector is sensitive to potential non-Standard Model physics, including interactions with WIMPs. We discuss the backgrounds present in the WIMP region of interest and explore the impact of slow surface event contamination when searching for a WIMP signal.

  3. Search for Majorana Neutrinos Near the Inverted Mass Hierarchy Region with KamLAND-Zen

    NASA Astrophysics Data System (ADS)

    Gando, A.; Gando, Y.; Hachiya, T.; Hayashi, A.; Hayashida, S.; Ikeda, H.; Inoue, K.; Ishidoshiro, K.; Karino, Y.; Koga, M.; Matsuda, S.; Mitsui, T.; Nakamura, K.; Obara, S.; Oura, T.; Ozaki, H.; Shimizu, I.; Shirahata, Y.; Shirai, J.; Suzuki, A.; Takai, T.; Tamae, K.; Teraoka, Y.; Ueshima, K.; Watanabe, H.; Kozlov, A.; Takemoto, Y.; Yoshida, S.; Fushimi, K.; Banks, T. I.; Berger, B. E.; Fujikawa, B. K.; O'Donnell, T.; Winslow, L. A.; Efremenko, Y.; Karwowski, H. J.; Markoff, D. M.; Tornow, W.; Detwiler, J. A.; Enomoto, S.; Decowski, M. P.; KamLAND-Zen Collaboration

    2016-08-01

    We present an improved search for neutrinoless double-beta (0 ν β β ) decay of 136Xe in the KamLAND-Zen experiment. Owing to purification of the xenon-loaded liquid scintillator, we achieved a significant reduction of the Agm110 contaminant identified in previous searches. Combining the results from the first and second phase, we obtain a lower limit for the 0 ν β β decay half-life of T1/2 0 ν>1.07 ×1 026 yr at 90% C.L., an almost sixfold improvement over previous limits. Using commonly adopted nuclear matrix element calculations, the corresponding upper limits on the effective Majorana neutrino mass are in the range 61-165 meV. For the most optimistic nuclear matrix elements, this limit reaches the bottom of the quasidegenerate neutrino mass region.

  4. Characterization and modeling of a low background HPGe detector

    NASA Astrophysics Data System (ADS)

    Dokania, N.; Singh, V.; Mathimalar, S.; Nanal, V.; Pal, S.; Pillay, R. G.

    2014-05-01

    A high efficiency, low background counting setup has been made at TIFR consisting of a special HPGe detector (~ 70 %) surrounded by a low activity copper+lead shield. Detailed measurements are performed with point and extended geometry sources to obtain a complete response of the detector. An effective model of the detector has been made with GEANT4 based Monte Carlo simulations which agrees with experimental data within 5%. This setup will be used for qualification and selection of radio-pure materials to be used in a cryogenic bolometer for the study of Neutrinoless Double Beta Decay in 124Sn as well as for other rare event studies. Using this setup, radio-impurities in the rock sample from India-based Neutrino Observatory (INO) site have been estimated.

  5. (α, γ) reaction induced background events for rare event experiments

    NASA Astrophysics Data System (ADS)

    Tiwari, Ashok; Zhang, Chao; Mei, Dongming

    2016-09-01

    We report an observation of (α, γ) reaction at the Soudan mine. With a 12-Liter scintillation neutron detector at Soudan mine for about 5 years of data taking, we have observed (α, γ) reaction, which can generate potential background events for dark matter and neutrinoless double-beta decay experiments. We have simulated the alpha flux from radon decay using the measured radon concentration in Soudan mine. The convolution of the alpha flux and the cross-section of (α, γ) allows us to determine the rate of high energy gamma from (α, γ) reaction. This rate is compared to the measured event rate. We demonstrate that the modulation of (α, γ) event rate has similar pattern as the radon modulation observed independently in Soudan mine. This work is supported by NSF in part by the NSF PHY-0758120, DOE Grant DE-FG02-10ER46709, and the State of South Dakota.

  6. Testing the Ge detectors for the MAJORANA DEMONSTRATOR

    SciTech Connect

    Xu, W.; Abgrall, N.; Aguayo, E.; Avignone, F. T.; Barabash, A. S.; Bertrand, F. E.; Boswell, M.; Brudanin, V.; Busch, M.; Byram, D.; Caldwell, A. S.; Chan, Y. -D.; Christofferson, C. D.; Combs, D. C.; Cuesta, C.; Detwiler, J. A.; Doe, P. J.; Efremenko, Yu.; Egorov, V.; Ejiri, H.; Elliott, S. R.; Fast, J. E.; Finnerty, P.; Fraenkle, F. M.; Galindo-Uribarri, A.; Giovanetti, G. K.; Goett, J.; Green, M. P.; Gruszko, J.; Guiseppe, V. E.; Gusev, K.; Hallin, A. L.; Hazama, R.; Hegai, A.; Henning, R.; Hoppe, E. W.; Howard, S.; Howe, M. A.; Keeter, K. J.; Kidd, M. F.; Kochetov, O.; Konovalov, S. I.; Kouzes, R. T.; LaFerriere, B. D.; Leon, J.; Leviner, L. E.; Loach, J. C.; MacMullin, J.; MacMullin, S.; Martin, R. D.; Meijer, S.; Mertens, S.; Nomachi, M.; Orrell, J. L.; O'Shaughnessy, C.; Overman, N. R.; Phillips, D. G.; Poon, A. W.P.; Pushkin, K.; Radford, D. C.; Rager, J.; Rielage, K.; Robertson, R. G.H.; Romero-Romero, E.; Ronquest, M. C.; Schubert, A. G.; Shanks, B.; Shima, T.; Shirchenko, M.; Snavely, K. J.; Snyder, N.; Suriano, A. M.; Thompson, J.; Timkin, V.; Tornow, W.; Trimble, J. E.; Varner, R. L.; Vasilyev, S.; Vetter, K.; Vorren, K.; White, B. R.; Wilkerson, J. F.; Wiseman, C.; Yakushev, E.; Young, A. R.; Yu, C. -H.; Yumatov, V.

    2015-03-24

    High purity germanium (HPGe) crystals will be used for the MAJORANA DEMONSTRATOR, where they serve as both the source and the detector for neutrinoless double beta decay. It is crucial for the experiment to understand the performance of the HPGe crystals. A variety of crystal properties are being investigated, including basic properties such as energy resolution, efficiency, uniformity, capacitance, leakage current and crystal axis orientation, as well as more sophisticated properties, e.g. pulse shapes and dead layer and transition layer distributions. In this talk, we will present our measurements that characterize the HPGe crystals. We will also discuss the our simulation package for the detector characterization setup, and show that additional information can be extracted from data-simulation comparisons.

  7. Constraining bilinear R-parity violation from neutrino masses

    NASA Astrophysics Data System (ADS)

    Góźdź, Marek; Kamiński, Wiesław A.

    2008-10-01

    We confront the R-parity violating minimal supersymmetric standard model with the neutrino oscillation data. Investigating the 1-loop particle-sparticle diagrams with additional bilinear insertions on the external neutrino lines we construct the relevant contributions to the neutrino mass matrix. A comparison of the so-obtained matrices with the experimental ones assuming normal or inverted hierarchy and taking into account possible CP-violating phases allows to set constraints on the values of the bilinear coupling constants. A similar calculation is presented with the input from the Heidelberg-Moscow neutrinoless double beta decay experiment. We base our analysis on the renormalization group evolution of the minimal supersymmetric standard model parameters which are unified at the grand unified theory scale. Using the obtained bounds we calculate the contributions to the Majorana neutrino transition magnetic moments.

  8. Design, fabrication, and testing of the CUORE detector calibration system

    NASA Astrophysics Data System (ADS)

    Dally, Adam

    2013-04-01

    CUORE, the Cryogenic Underground Observatory for Rare Events, is a neutrinoless double beta decay experiment with an active mass of 206 kg of ^130Te. The detector consists of 988 TeO2 bolometers operating at 10 mK. The signature of 0νββ decay is an excess of events at the Q-value of 2528 keV. Understanding the energy response is critical for event identification, but this presents many challenges. The detector requires ultra-low background radiation, vacuum compatible materials, and cryogenic temperatures. Individual energy calibration of the bolometers is achieved by placing radioactive sources between detectors inside the cryostat. A source deployment and thermalization system that meets the background and thermal requirements of the CUORE experiment has been developed. This talk will discuss the design, fabrication, and testing of the CUORE detector calibration system.

  9. The SNO+ Scintillator Purification Plant and Projected Sensitivity to Solar Neutrinos in the Pure Scintillator Phase

    NASA Astrophysics Data System (ADS)

    Pershing, Teal; SNO+ Collaboration

    2016-03-01

    The SNO+ detector is a neutrino and neutrinoless double-beta decay experiment utilizing the renovated SNO detector. In the second phase of operation, the SNO+ detector will contain 780 tons of organic liquid scintillator composed of 2 g/L 2,5-diphenyloxazole (PPO) in linear alkylbenzene (LAB). In this phase, SNO+ will strive to detect solar neutrinos in the sub-MeV range, including CNO production neutrinos and pp production neutrinos. To achieve the necessary detector sensitivity, a four-part scintillator purification plant has been constructed in SNOLAB for the removal of ionic and radioactive impurities. We present an overview of the SNO+ scintillator purification plant stages, including distillation, water extraction, gas stripping, and metal scavenger columns. We also give the projected SNO+ sensitivities to various solar-produced neutrinos based on the scintillator plant's projected purification efficiency.

  10. The Δ(27) flavor 3-3-1 model with neutral leptons

    NASA Astrophysics Data System (ADS)

    Vien, V. V.; Cárcamo Hernández, A. E.; Long, H. N.

    2016-12-01

    We build the first 3-3-1 model based on the Δ (27) discrete group symmetry, consistent with fermion masses and mixings. In the model under consideration, the neutrino masses are generated from a combination of type-I and type-II seesaw mechanisms mediated by three heavy right-handed Majorana neutrinos and three SU (3)L scalar antisextets, respectively. Furthermore, from the consistency of the leptonic mixing angles with their experimental values, we obtain a non-vanishing leptonic Dirac CP violating phase of -π/2. Our model features an effective Majorana neutrino mass parameter of neutrinoless double beta decay, with values mββ = 10 and 18 meV for the normal and the inverted neutrino mass hierarchies, respectively.

  11. Status and Perspectives of the COBRA Experiment

    NASA Astrophysics Data System (ADS)

    Wonsak, Björn

    COBRA is a neutrinoless double beta decay (0νββ) experiment using an array of Cadmium-Zinc-Telluride semiconductor detectors, the isotope of interest being 116Cd with a Q-value of 2814 keV. To investigate the experimental challenges of operating CdZnTe detectors in low background mode and to identify potential background components, a demonstrator setup is operated at the Gran Sasso underground laboratory (LNGS) in Italy, while additional studies are proceeding in surface laboratories. The experiment consists of monolithic, calorimetric detectors of coplanar grid design (CPG de- tectors). These detectors have a size of 1×1×1 cm3 and are arranged in four layers of 4×4 detectors. An overview of the current status and of future perspectives is given. Results of pulse shape analyses are presented as well as background estimates using the data collected so far.

  12. Investigation of Neutrino Properties with Bolometric Detectors

    SciTech Connect

    Heeger, Karsten M

    2014-11-01

    Neutrino mass and mixing are amongst the major discoveries of the past decade. The particle nature of neutrinos and the hierarchy of mass eigenstates, however, are unknown. Neutrinoless double beta-decay (0νββ) is the only known mechanism to test whether neutrinos are their own antiparticles. The observation of 0νββ would imply lepton number violation and show that neutrinos have Majorana mass. This report describes research activities performed at the University of Wisconsin in 2011-2014 aimed at the search for 0νββ with CUORE-0 and CUORE with the goal of exploring the inverted mass hierarchy region and probing an effective neutrino mass of ~40- 120 meV.

  13. Emulation workbench for position sensitive gaseous scintillation detectors

    NASA Astrophysics Data System (ADS)

    Pereira, L.; Margato, L. M. S.; Morozov, A.; Solovov, V.; Fraga, F. A. F.

    2015-12-01

    Position sensitive detectors based on gaseous scintillation proportional counters with Anger-type readout are being used in several research areas such as neutron detection, search for dark matter and neutrinoless double beta decay. Design and optimization of such detectors are complex and time consuming tasks. Simulations, while being a powerful tool, strongly depend on the light transfer models and demand accurate knowledge of many parameters, which are often not available. Here we describe an alternative approach based on the experimental evaluation of a detector using an isotropic point-like light source with precisely controllable light emission properties, installed on a 3D positioning system. The results obtained with the developed setup at validation conditions, when the scattered light is strongly suppressed show good agreement with simulations.

  14. Low background stainless steel for the pressure vessel in the PandaX-II dark matter experiment

    NASA Astrophysics Data System (ADS)

    Zhang, T.; Fu, C.; Ji, X.; Liu, J.; Liu, X.; Wang, X.; Yao, C.; Yuan, Xunhua

    2016-09-01

    We report on the custom produced low radiation background stainless steel and the welding rod for the PandaX experiment, one of the deep underground experiments to search for dark matter and neutrinoless double beta decay using xenon. The anthropogenic 60Co concentration in these samples is at the range of 1 mBq/kg or lower. We also discuss the radioactivity of nuclear-grade stainless steel from TISCO which has a similar background rate. The PandaX-II pressure vessel was thus fabricated using the stainless steel from CISRI and TISCO. Based on the analysis of the radioactivity data, we also made discussions on potential candidate for low background metal materials for future pressure vessel development.

  15. The Sanford underground research facility at Homestake

    SciTech Connect

    Heise, J.

    2014-06-24

    The former Homestake gold mine in Lead, South Dakota is being transformed into a dedicated laboratory to pursue underground research in rare-process physics, as well as offering research opportunities in other disciplines such as biology, geology and engineering. A key component of the Sanford Underground Research Facility (SURF) is the Davis Campus, which is in operation at the 4850-foot level (4300 m.w.e) and currently hosts three projects: the LUX dark matter experiment, the MAJORANA DEMONSTRATOR neutrinoless double-beta decay experiment and the CUBED low-background counter. Plans for possible future experiments at SURF are well underway and include long baseline neutrino oscillation experiments, future dark matter experiments as well as nuclear astrophysics accelerators. Facility upgrades to accommodate some of these future projects have already started. SURF is a dedicated facility with significant expansion capability.

  16. The development of SiGHT: an ultra low background photosensor

    NASA Astrophysics Data System (ADS)

    Wang, Y.; Fan, A.; Fiorillo, G.; Galbiati, C.; Guan, M. Y.; Korga, G.; Pantic, E.; Razeto, A.; Renshaw, A.; Rossi, B.; Suvorov, Y.; Wang, H.; Yang, C. G.

    2016-09-01

    The Silicon Geiger Hybrid Tube (SiGHT) is a novel photosensor designed for future generations of rare event search experiments using noble liquids. The main idea is to replace conventional multi-dynode photomultiplier tubes (PMTs) with a hybrid technology, consisting of a low temperature sensitive bialkali photocathode for conversion of photons into photoelectrons and a low dark count silicon photomultiplier (SiPM) for photoelectron signal amplification. SiGHT can achieve ultra low internal radioactivity, high quantum efficiency and stable performance at low temperatures, which are required features for rare event searches such as direct dark matter detection and neutrinoless double beta decay experiments. The first SiGHT prototype fabrication is in progress at UCLA. The current status of the development is presented.

  17. Precision Studies at the Neutrino Frontier

    NASA Astrophysics Data System (ADS)

    Heeger, Karsten M.

    2013-04-01

    Neutrinos were proposed as a remedy to explain nuclear beta decay and are now essential in our understanding of the Universe. Neutrinos determine the abundance of light elements, are critical to supernova explosions, and may hold the key to understanding the matter-antimatter asymmetry. Studies of neutrinos from the Sun and nuclear reactors have confirmed the prediction of solar models and provided evidence for neutrino flavor oscillation. The observation of neutrino oscillation is amongst the major discoveries and demands that we make the first significant revision of the Standard Model. The search for neutrinoless double beta decay is the only experimental approach to probing the Majorana nature of neutrinos and will provide insight into the fundamental nature of neutrino mass. I will review Stuart Freedman's contributions to neutrino physics and in advancing the field to precision measurements.

  18. Reflectance dependence of polytetrafluoroethylene on thickness for xenon scintillation light

    NASA Astrophysics Data System (ADS)

    Haefner, J.; Neff, A.; Arthurs, M.; Batista, E.; Morton, D.; Okunawo, M.; Pushkin, K.; Sander, A.; Stephenson, S.; Wang, Y.; Lorenzon, W.

    2017-06-01

    Many rare event searches including dark matter direct detection and neutrinoless double beta decay experiments take advantage of the high VUV reflective surfaces made from polytetrafluoroethylene (PTFE) reflector materials to achieve high light collection efficiency in their detectors. As the detectors have grown in size over the past decade, there has also been an increased need for ever thinner detector walls without significant loss in reflectance to reduce dead volumes around active noble liquids, outgassing, and potential backgrounds. We report on the experimental results to measure the dependence of the reflectance on thickness of two PTFE samples at wavelengths near 178 nm. No change in reflectance was observed as the wall thickness of a cylindrically shaped PTFE vessel immersed in liquid xenon was varied between 1 mm to 9.5 mm.

  19. Low background signal readout electronics for the Majorana Demonstrator

    SciTech Connect

    Guinn, I.; Abgrall, N.; Avignone, F. T.; Barabash, A. S.; Bertrand, F. E.; Brudanin, V.; Busch, M.; Buuck, M.; Byram, D.; Caldwell, A. S.; Chan, Y-D; Christofferson, C. D.; Cuesta, C.; Detwiler, J. A.; Efremenko, Yu; Ejiri, H.; Elliott, S. R.; Galindo-Uribarri, A.; Giovanetti, G. K.; Goett, J.; Green, M. P.; Gruszko, J.; Guiseppe, V. E.; Henning, R.; Hoppe, E. W.; Howard, S.; Howe, M. A.; Jasinski, B. R.; Keeter, K. J.; Kidd, M. F.; Konovalov, S. I.; Kouzes, R. T.; LaFerriere, B. D.; Leon, J.; MacMullin, J.; Martin, R. D.; Meijer, S. J.; Mertens, S.; Orrell, J. L.; O'Shaughnessy, C.; Overman, N. R.; Poon, A. W. P.; Radford, D. C.; Rager, J.; Rielage, K.; Robertson, R. G. H.; Romero-Romero, E.; Ronquest, M. C.; Shanks, B.; Shirchenko, M.; Snyder, N.; Suriano, A. M.; Tedeschi, D.; Trimble, J. E.; Varner, R. L.; Vasilyev, S.; Vetter, K.; Vorren, K.; White, B. R.; Wilkerson, J. F.; Wiseman, C.; Xu, W.; Yakushev, E.; Yu, C-H; Yumatov, V.

    2015-05-01

    The Majorana Demonstrator is a planned 40 kg array of Germanium detectors intended to demonstrate the feasibility of constructing a tonne-scale experiment that will seek neutrinoless double beta decay (0νββ) in 76Ge. In such an experiment we require backgrounds of less than 1 count/tonne-year in the 4 keV region of interest around the 2039 keV Q-value of the ββ decay. Moreover, designing low-noise electronics, which must be placed in close proximity to the detectors, presents a challenge to reaching this background target. Finally, this paper will discuss the Majorana collaboration's solutions to some of these challenges.

  20. The Majorana Demonstrator radioassay program

    SciTech Connect

    Abgrall, N.; Arnquist, I. J.; Avignone, F. T.; Back, H. O.; Barabash, A. S.; Bertrand, F. E.; Boswell, Melissa; Bradley, A. W.; Brudanin, V.; Busch, M.; Buuck, M.; Byram, D.; Caldwell, A. S.; Chan, Y. -D.; Christofferson, C. D.; Chu, Pinghan; Cuesta, C.; Detwiler, J. A.; Dunmore, J. A.; Efremenko, Yu.; Ejiri, H.; Elliott, S. R.; Finnerty, P.; Galindo-Uribarri, A.; Gehman, V. M.; Gilliss, T.; Giovanetti, G. K.; Goett, John Jerome; Green, M. P.; Gruszko, J.; Guinn, I. S.; Guiseppe, V. E.; Henning, R.; Hoppe, E. W.; Howard, S.; Howe, M. A.; Jasinski, B. R.; Johnson, R. A.; Keeter, K. J.; Kidd, M. F.; Kochetov, O.; Konovalov, S. I.; Kouzes, R. T.; LaFerriere, B. D.; Leon, J.; Loach, J. C.; MacMullin, J.; MacMullin, S.; Martin, R. D.; Massarczyk, Ralph; Meijer, S.; Mertens, S.; Miller, M. L.; Orrell, J. L.; O'Shaughnessy, C.; Overman, N. R.; Poon, A. W. P.; Pushkin, K.; Radford, D. C.; Rager, J.; Rielage, Keith Robert; Robertson, R. G. H.; Romero-Romero, E.; Ronquest, M. C.; Schubert, A. G.; Shanks, B.; Shirchenko, M.; Snavely, K. J.; Snyder, N.; Steele, D.; Suriano, A. M.; Tedeschi, D.; Trimble, J. E.; Varner, R. L.; Vasilyev, S.; Vetter, K.; Vorren, K.; White, B. R.; Wilkerson, J. F.; Wiseman, C.; Xu, W.; Yakushev, E.; Yu, C. -H.; Yumatov, V.; Zhitnikov, I.

    2016-05-03

    The Majorana collaboration is constructing the Majorana Demonstrator at the Sanford Underground Research Facility at the Homestake gold mine, in Lead, SD. The apparatus will use Ge detectors, enriched in isotope 76Ge, to demonstrate the feasibility of a large-scale Ge detector experiment to search for neutrinoless double beta decay. The long half-life of this postulated process requires that the apparatus be extremely low in radioactive isotopes whose decays may produce backgrounds to the search. The radioassay program conducted by the collaboration to ensure that the materials comprising the apparatus are sufficiently pure is described. The resulting measurements from gamma-ray counting, neutron activation and mass spectroscopy of the radioactive-isotope contamination for the materials studied for use in the detector are reported. In conclusion, we interpret these numbers in the context of the expected background for the experiment.