WorldWideScience

Sample records for beta decay energies

  1. Measuring pion beta decay with high-energy pion beams

    International Nuclear Information System (INIS)

    McFarlane, W.K.; Hoffman, C.M.

    1993-01-01

    Improved measurements of the pion beta decay rate are possible with an intense high-energy pion beam. The rate for the decay π + → π 0 e + vε is predicted by the Standard Model (SM) to be R(π + → π 0 e + vε) = 0.3999±0.0005 s -1 . The best experimental number, obtained using in-flight decays, is R(π + → π 0 e + vε) = 0.394 ± 0.015 s -1 . A precise measurement would test the SM by testing the unitarity of the Cabibbo-Kobayashi-Maskawa matrix for which one analysis of the nuclear beta decay data has shown a 0.4% discrepancy. Several nuclear correction factors, needed for nuclear decay, are not present for pion beta decay, so that an experiment at the 0.2% level would be a significant one. Detailed study of possible designs will be needed, as well as extensive testing of components. The reduction of systematic errors to the 0.1% level can only be done over a period of years with a highly stable apparatus and beam. At a minimum, three years of occupancy of a beam line, with 800 hours per year, would be required

  2. The {beta}-decay Paul trap: A radiofrequency-quadrupole ion trap for precision {beta}-decay studies

    Energy Technology Data Exchange (ETDEWEB)

    Scielzo, N.D., E-mail: scielzo1@llnl.gov [Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Li, G. [Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Department of Physics, McGill University, Montreal, Quebec, Canada H3A 2T8 (Canada); Sternberg, M.G.; Savard, G. [Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Department of Physics, University of Chicago, Chicago, Illinois 60637 (United States); Bertone, P.F. [Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Buchinger, F. [Department of Physics, McGill University, Montreal, Quebec, Canada H3A 2T8 (Canada); Caldwell, S. [Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Department of Physics, University of Chicago, Chicago, Illinois 60637 (United States); Clark, J.A. [Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Crawford, J. [Department of Physics, McGill University, Montreal, Quebec, Canada H3A 2T8 (Canada); Deibel, C.M. [Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Joint Institute for Nuclear Astrophysics, Michigan State University, East Lansing, Michigan 48824 (United States); Fallis, J. [Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Department of Physics and Astronomy, University of Manitoba, Winnipeg, Manitoba, Canada R3T 2N2 (Canada); Greene, J.P. [Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); and others

    2012-07-21

    The {beta}-decay Paul trap is a linear radiofrequency-quadrupole ion trap that has been developed for precision {beta}-decay studies. The design of the trap electrodes allows a variety of radiation detectors to surround the cloud of trapped ions. The momentum of the low-energy recoiling daughter nuclei following {beta} decay is negligibly perturbed by scattering and is available for study. This advantageous property of traps allows the kinematics of particles that are difficult or even impossible to directly detect to be precisely reconstructed using conservation of energy and momentum. An ion-trap system offers several advantages over atom traps, such as higher trapping efficiencies and element-independent capabilities. The first precision experiment using this system is a measurement of {beta}-decay angular correlations in the decay of {sup 8}Li performed by inferring the momentum of the neutrino from the kinematic shifts imparted to the breakup {alpha} particles. Many other {beta}-decay studies that would benefit from a determination of the nuclear recoil can be performed with this system.

  3. Search for $\\beta$-transitions with the lowest decay energy for a determination of the neutrino mass

    CERN Multimedia

    From a variety of $\\beta$-transitions only those with decay energies of a few keV and smaller are considered suitable for a determination of the neutrino mass on a sub-eV level. The decay energy of a transition can be very small, if, e.g., in an allowed $\\beta$-decay or electron-capture transition, a nuclear excited state of the daughter nuclide is populated whose energy is very close to the mass difference of the transition nuclides. Investigation of these transitions can also be useful for the assessment of a validity of the current $\\beta$-decay theory in the region of vanishingly small decay energies. The authors of this proposal have found several such $\\beta$-transitions whose decay energies are expected to be extremely small. In order to assess the suitability of these $\\beta$-transitions for the determination of the neutrino mass, measurements of the mass differences of the transition nuclides must be carried out with a sub-keV uncertainty. Presently, only high-precision Penning-trap mass spectrometry...

  4. Beta-decay rate and beta-delayed neutron emission probability of improved gross theory

    Science.gov (United States)

    Koura, Hiroyuki

    2014-09-01

    A theoretical study has been carried out on beta-decay rate and beta-delayed neutron emission probability. The gross theory of the beta decay is based on an idea of the sum rule of the beta-decay strength function, and has succeeded in describing beta-decay half-lives of nuclei overall nuclear mass region. The gross theory includes not only the allowed transition as the Fermi and the Gamow-Teller, but also the first-forbidden transition. In this work, some improvements are introduced as the nuclear shell correction on nuclear level densities and the nuclear deformation for nuclear strength functions, those effects were not included in the original gross theory. The shell energy and the nuclear deformation for unmeasured nuclei are adopted from the KTUY nuclear mass formula, which is based on the spherical-basis method. Considering the properties of the integrated Fermi function, we can roughly categorized energy region of excited-state of a daughter nucleus into three regions: a highly-excited energy region, which fully affect a delayed neutron probability, a middle energy region, which is estimated to contribute the decay heat, and a region neighboring the ground-state, which determines the beta-decay rate. Some results will be given in the presentation. A theoretical study has been carried out on beta-decay rate and beta-delayed neutron emission probability. The gross theory of the beta decay is based on an idea of the sum rule of the beta-decay strength function, and has succeeded in describing beta-decay half-lives of nuclei overall nuclear mass region. The gross theory includes not only the allowed transition as the Fermi and the Gamow-Teller, but also the first-forbidden transition. In this work, some improvements are introduced as the nuclear shell correction on nuclear level densities and the nuclear deformation for nuclear strength functions, those effects were not included in the original gross theory. The shell energy and the nuclear deformation for

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

    International Nuclear Information System (INIS)

    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. (author)

  6. In-trap decay spectroscopy for {beta}{beta} decays

    Energy Technology Data Exchange (ETDEWEB)

    Brunner, Thomas

    2011-01-18

    The presented work describes the implementation of a new technique to measure electron-capture (EC) branching ratios (BRs) of intermediate nuclei in {beta}{beta} decays. This technique has been developed at TRIUMF in Vancouver, Canada. It facilitates one of TRIUMF's Ion Traps for Atomic and Nuclear science (TITAN), the Electron Beam Ion Trap (EBIT) that is used as a spectroscopy Penning trap. Radioactive ions, produced at the radioactive isotope facility ISAC, are injected and stored in the spectroscopy Penning trap while their decays are observed. A key feature of this technique is the use of a strong magnetic field, required for trapping. It radially confines electrons from {beta} decays along the trap axis while X-rays, following an EC, are emitted isotropically. This provides spatial separation of X-ray and {beta} detection with almost no {beta}-induced background at the X-ray detector, allowing weak EC branches to be measured. Furthermore, the combination of several traps allows one to isobarically clean the sample prior to the in-trap decay spectroscopy measurement. This technique has been developed to measure ECBRs of transition nuclei in {beta}{beta} decays. Detailed knowledge of these electron capture branches is crucial for a better understanding of the underlying nuclear physics in {beta}{beta} decays. These branches are typically of the order of 10{sup -5} and therefore difficult to measure. Conventional measurements suffer from isobaric contamination and a dominating {beta} background at theX-ray detector. Additionally, X-rays are attenuated by the material where the radioactive sample is implanted. To overcome these limitations, the technique of in-trap decay spectroscopy has been developed. In this work, the EBIT was connected to the TITAN beam line and has been commissioned. Using the developed beam diagnostics, ions were injected into the Penning trap and systematic studies on injection and storage optimization were performed. Furthermore, Ge

  7. A detection system for very low-energy protons from {beta}-delayed proton decay

    Energy Technology Data Exchange (ETDEWEB)

    Spiridon, A.; Pollacco, E.; Trache, L.; Simmons, E.; McCleskey, M.; Roeder, B. T.; Tribble, R. E.; Pascovici, G.; Riallot, M.; Mols, J. P.; Kebbiri, M. [Cyclotron Institute, Texas A and M University, College Station, TX 77843-3366 (United States); CEA/IRFU Saclay, Gif-sur-Yvette (France); Cyclotron Institute, Texas A and M University, College Station, TX 77843-3366 (United States); Institut fuer Kernphysik der Universitaet zu Koeln, D-50937 Koeln (Germany); CEA/IRFU Saclay, Gif-sur-Yvette (France)

    2012-11-20

    We have recently developed a gas based detection system called AstroBox, motivated by nuclear astrophysics studies. The goal was to detect very low-energy protons from {beta}-delayed p-decay with reduced beta background and improved energy resolution. The detector was tested using the {beta}-delayed proton-emitter 23Al previously studied with a set-up based on thin double-sided Si strip detectors. The proton spectrum obtained with AstroBox showed no beta background down to {approx}80 keV. The low energy (206 keV, 267 keV) proton peaks were positively identified, well separated, and the resolution was improved.

  8. Sizeable beta-strength in 31Ar (beta 3p) decay

    DEFF Research Database (Denmark)

    T. Koldste, G.; Blank, B.; J. G. Borge, M.

    2014-01-01

    We present for the first time precise spectroscopic information on the recently discovered decay mode beta-delayed 3p-emission. The detection of the 3p events gives an increased sensitivity to the high energy part of the Gamow-Teller strength distribution from the decay of 31Ar revealing that as ...... that as much as 30% of the strength resides in the beta-3p decay mode. A simplified description of how the main decay modes evolve as the excitation energy increases in 31Cl is provided....

  9. Neutrinoless double beta decay

    Indian Academy of Sciences (India)

    2012-10-06

    Oct 6, 2012 ... Anyhow, the 'multi-isotope' ansatz is needed to compensate for matrix element ... The neccessary half-life requirement to touch this ... site energy depositions (like double beta decay) and multiple site interactions (most of.

  10. Beta-decay and decay heat. Summary report of consultants' meeting

    International Nuclear Information System (INIS)

    Nicols, A.L.

    2006-01-01

    Experts on decay data and decay heat calculations participated in a Consultants' Meeting organized at IAEA Headquarters on 12-14 December 2005. Debate focused on the validation of decay heat calculations as a function of cooling time for fuel irradiated in power reactors through comparisons with experimental benchmark data. Both the current understanding and quantification of mean beta and gamma decay energies were reviewed with respect to measurements and the Gross Theory of Beta Decay. Particular emphasis was placed on the known development of total absorption gamma-ray spectroscopy (TAGS), and detailed discussions took place to formulate the measurement requirements for mean beta and gamma data of individual radionuclides. This meeting was organized in cooperation with the OECD/NEA Working Party for Evaluation and Cooperation (WPEC). Proposals and recommendations were made to resolve particular difficulties, and an initial list of fission products was produced for TAGS studies. The discussions, conclusions and recommendations of the meeting are briefly described in this report. (author)

  11. Beta decay of 22O

    International Nuclear Information System (INIS)

    Hubert, F.; Dufour, J.P.; Moral, R. del; Fleury, A.; Jean, D.; Pravikoff, M.S.; Delagrange, H.; Geissel, H.; Schmidt, K.H.; Hanelt, E.

    1989-01-01

    The beta-gamma spectroscopic study of 22 O is presented. This nucleus, produced as a projectile-like fragment from the interaction of a 60 MeV/n 40 Ar beam with a Be target, has been separated by the LISE spectrometer. Several gamma rays from 22 O decay have been observed, from which a half-life of (2.25±0.15) s has been determined. Accurate excitation energies have been deduced for several states in 22 F. A partial beta decay scheme of 22 O has been established. Experimental results have been compared with shell model calculations. (orig.)

  12. Beta and muon decays

    International Nuclear Information System (INIS)

    Galindo, A.; Pascual, P.

    1967-01-01

    These notes represent a series of lectures delivered by the authors in the Junta de Energia Nuclear, during the Spring term of 1965. They were devoted to graduate students interested in the Theory of Elementary Particles. Special emphasis was focussed into the computational problems. Chapter I is a review of basic principles (Dirac equation, transition probabilities, final state interactions.) which will be needed later. In Chapter II the four-fermion punctual Interaction is discussed, Chapter III is devoted to the study of beta-decay; the main emphasis is given to the deduction of the formulae corresponding to electron-antineutrino correlation, electron energy spectrum, lifetimes, asymmetry of electrons emitted from polarized nuclei, electron and neutrino polarization and time reversal invariance in beta decay. In Chapter IV we deal with the decay of polarized muons with radiative corrections. Chapter V is devoted to an introduction to C.V.C. theory. (Author)

  13. Beta and muon decays

    Energy Technology Data Exchange (ETDEWEB)

    Galindo, A; Pascual, P

    1967-07-01

    These notes represent a series of lectures delivered by the authors in the Junta de Energia Nuclear, during the Spring term of 1965. They were devoted to graduate students interested in the Theory of Elementary Particles. Special emphasis was focussed into the computational problems. Chapter I is a review of basic principles (Dirac equation, transition probabilities, final state interactions.) which will be needed later. In Chapter II the four-fermion punctual Interaction is discussed, Chapter III is devoted to the study of beta-decay; the main emphasis is given to the deduction of the formulae corresponding to electron-antineutrino correlation, electron energy spectrum, lifetimes, asymmetry of electrons emitted from polarized nuclei, electron and neutrino polarization and time reversal invariance in beta decay. In Chapter IV we deal with the decay of polarized muons with radiative corrections. Chapter V is devoted to an introduction to C.V.C. theory. (Author)

  14. JENDL FP decay data file 2000 and the beta-decay theory

    International Nuclear Information System (INIS)

    Yoshida, Tadashi; Katakura, Jun Ichi; Tachibana, Takahiro

    2002-01-01

    JENDL FP Decay Data File 2000 has been developed as one of the special purpose files of the Japanese Evaluated Nuclear Data Library (JENDL), which constitutes a versatile nuclear data basis for science and technology. In the format of ENDF-6 this file includes the decay data for 1087 unstable fission product (FP) nuclides and 142 stable nuclides as their daughters. The primary purpose of this file is to use in the summation calculation of FP decay heat, which plays a critical role in nuclear safety analysis; the loss-of-coolant accident analysis of reactors, for example. The data for a given nuclide are its decay modes, the Q value, the branching ratios, the average energies released in the form of beta- and gamma-rays per decay, and their spectral data. The primary source of the decay data adopted here is the ENSDF (Evaluated Nuclear Structure Data File). The data in ENSDF, however, cover only the measured values. The data of the short-lived nuclides, which are essential for the decay heat calculations at short cooling times, are often fully lacking or incomplete even if they exist. This is mainly because of their short half-life nature. For such nuclides a theoretical model calculation is applied in order to fill the gaps between the true and the experimentally known decay schemes. In practice we have to predict the average decay energies and the spectral data for a lot of short-lived FPs by use of beta-decay theories. Thus the beta-decay theory plays a very important role in generating the FP decay data file

  15. Study of $\\beta$-delayed neutron decay of $^{8}$He

    CERN Multimedia

    The goal of the present proposal is to study $\\beta$-delayed neutron decay branch of $^{8}$He. The energy spectra of the emitted neutrons will be measured in the energy range of 0.1 – 6 MeV using the VANDLE spectrometer. Using coincident $\\gamma$-ray measurement, components of the spectrum corresponding to transitions to the ground- and first- excited states of $^{7}$Li will be disentangled. The new data will allow us to get a more complete picture of the $\\beta$-decay of $^{8}$He and to clarify the discrepancy between the B(GT) distributions derived from the $\\beta$-decay and $^{8}$He(p, n)$^{8}$Li reaction studies.

  16. Method and apparatus for induced nuclear beta decay

    International Nuclear Information System (INIS)

    Reiss, H.

    1986-01-01

    This invention relates to a method and apparatus for inducing beta decay transition that are normally inhibited by angular momentum or parity considerations. According to one aspect of this invention a method of inducing nuclear beta decay transition comprises providing a medium which includes atomic nuclei that have forbidden beta decay transition in which the initial and final nuclear states do not have the same intrinsic parity or have total angular momenta which differ by more than one quantum unit of angular momentum, and applying to the medium an electromagnetic field which has an intensity sufficient to provide the angular momentum or intrinsic parity necessary to overcome the forbiddenness of the beta decay transition of the atomic nuclei, thereby to induce the beta decay transitions. According to another aspect of this invention an apparatus for inducing beta decay transition comprises a medium which includes atomic nuclei that have forbidden beta decay transitions in which the initial and final nuclear states do not have the same intrinsic parity or have total angular momenta which differ by more than one quantum unit of angular momentum, field producing means for producing an electromagnetic field in the medium and means for energising the field producing means to establish the field at an intensity sufficient to provide the angular momentum or intrinsic parity necessary to overcome the forbiddenness of the beta decay transitions of the atomic nuclei. The energy released in these induced nuclear transition is useful for the controlled production of power. The induced beta dacay transitions are also useful to reduce the halflives of long-lived fission product wastes from conventional nuclear fission power plants

  17. Tests of the standard electroweak model in beta decay

    Energy Technology Data Exchange (ETDEWEB)

    Severijns, N.; Beck, M. [Universite Catholique de Louvain (UCL), Louvain-la-Neuve (Belgium); Naviliat-Cuncic, O. [Caen Univ., CNRS-ENSI, 14 (France). Lab. de Physique Corpusculaire

    2006-05-15

    We review the current status of precision measurements in allowed nuclear beta decay, including neutron decay, with emphasis on their potential to look for new physics beyond the standard electroweak model. The experimental results are interpreted in the framework of phenomenological model-independent descriptions of nuclear beta decay as well as in some specific extensions of the standard model. The values of the standard couplings and the constraints on the exotic couplings of the general beta decay Hamiltonian are updated. For the ratio between the axial and the vector couplings we obtain C{sub A},/C{sub V} = -1.26992(69) under the standard model assumptions. Particular attention is devoted to the discussion of the sensitivity and complementarity of different precision experiments in direct beta decay. The prospects and the impact of recent developments of precision tools and of high intensity low energy beams are also addressed. (author)

  18. Tests of the standard electroweak model in beta decay

    International Nuclear Information System (INIS)

    Severijns, N.; Beck, M.; Naviliat-Cuncic, O.

    2006-05-01

    We review the current status of precision measurements in allowed nuclear beta decay, including neutron decay, with emphasis on their potential to look for new physics beyond the standard electroweak model. The experimental results are interpreted in the framework of phenomenological model-independent descriptions of nuclear beta decay as well as in some specific extensions of the standard model. The values of the standard couplings and the constraints on the exotic couplings of the general beta decay Hamiltonian are updated. For the ratio between the axial and the vector couplings we obtain C A ,/C V = -1.26992(69) under the standard model assumptions. Particular attention is devoted to the discussion of the sensitivity and complementarity of different precision experiments in direct beta decay. The prospects and the impact of recent developments of precision tools and of high intensity low energy beams are also addressed. (author)

  19. Time reversal violation in radiative beta decay: experimental plans

    Science.gov (United States)

    Behr, J. A.; McNeil, J.; Anholm, M.; Gorelov, A.; Melconian, D.; Ashery, D.

    2017-01-01

    Some explanations for the excess of matter over antimatter in the universe involve sources of time reversal violation (TRV) in addition to the one known in the standard model of particle physics. We plan to search for TRV in a correlation between the momenta of the beta, neutrino, and the radiative gamma sometimes emitted in nuclear beta decay. Correlations involving three (out of four) momenta are sensitive at lowest order to different TRV physics than observables involving spin, such as electric dipole moments and spin-polarized beta decay correlations. Such experiments have been done in radiative kaon decay, but not in systems involving the lightest generation of quarks. An explicit low-energy physics model being tested produces TRV effects in the Fermi beta decay of the neutron, tritium, or some positron-decaying isotopes. We will present plans to measure the TRV asymmetry in radiative beta decay of laser-trapped 38mK at better than 0.01 sensitivity, including suppression of background from positron annihilation. Supported by NSERC, D.O.E., Israel Science Foundation. TRIUMF receives federal funding via a contribution agreement with the National Research Council of Canada.

  20. A background free double beta decay experiment

    International Nuclear Information System (INIS)

    Giomataris, I

    2011-01-01

    We present a new detection scheme for rejecting backgrounds in neutrino-less double beta decay experiments. It relies on the detection of Cherenkov light emitted by electrons in the MeV region. The momentum threshold is tuned to reach a good discrimination between background and good events. We consider many detector concepts and a range of target materials. The most promising is the high-pressure 136 Xe emitter where the required energy threshold is easily adjusted. Combination of this concept and a high pressure Time Projection Chamber could provide an optimal solution. A simple and low cost effective solution is the use of the Spherical Proportional Counter that provides, using a single read-out channel, two delayed signals from ionization and Cherenkov light. In solid-state double beta decay emitters, because of its higher density, the considered process is out of energy range. An escape will be the fabrication of double decay emitters having lower density by using for instance the aerogel technique. It is surprising that a technology used for particle identification in high-energy physics becomes a powerful tool for rejecting backgrounds in such low-energy experiments.

  1. Front-end electronics for accurate energy measurement of double beta decays

    International Nuclear Information System (INIS)

    Gil, A.; Díaz, J.; Gómez-Cadenas, J.J.; Herrero, V.; Rodriguez, J.; Serra, L.; Toledo, J.; Esteve, R.; Monzó, J.M.; Monrabal, F.; Yahlali, N.

    2012-01-01

    NEXT, a double beta decay experiment that will operate in Canfranc Underground Laboratory (Spain), aims at measuring the neutrinoless double-β decay of the 136Xe isotope using a TPC filled with enriched Xenon gas at high pressure operated in electroluminescence mode. One technological challenge of the experiment is to achieve resolution better than 1% in the energy measurement using a plane of UV sensitive photomultipliers readout with appropriate custom-made front-end electronics. The front-end is designed to be sensitive to the single photo-electron to detect the weak primary scintillation light produced in the chamber, and also to be able to cope with the electroluminescence signal (several hundred times higher and with a duration of microseconds). For efficient primary scintillation detection and precise energy measurement of the electroluminescent signals the front-end electronics features low noise and adequate amplification. The signal shaping provided allows the digitization of the signals at a frequency as low as 40 MHz.

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

    CERN Document Server

    Martín-Albo, J.; Ferrario, P.; Nebot-Guinot, M.; Gómez-Cadenas, J.J.; Álvarez, V.; Azevedo, C.D.R.; Borges, F.I.G.; Cárcel, S.; 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.; Gehman, V.M.; Goldschmidt, A.; González-Díaz, D.; Gutiérrez, R.M.; Henriques, C.A.O.; Hernando Morata, J.A.; Labarga, L.; Laing, A.; Lebrun, P.; Liubarsky, I.; López-March, N.; Lorca, D.; Losada, M.; Martínez-Lema, G.; Martínez, A.; Miller, T.; Monrabal, F.; Monserrate, M.; Monteiro, C.M.B.; Mora, F.J.; Moutinho, L.M.; Novella, P.; Nygren, D.; Para, A.; Perez, J.; Perez 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.; Stiegler, T.; Toledo, J.F.; Torrent, J.; Tsamalaidze, Z.; Veloso, J.F.C.A.; Villar, J.A.; Webb, R.; White, J.T.; Yahlali, N.; Yepes-Ramírez, H.; Hauptman, J.

    2016-01-01

    NEXT-100 is an electroluminescent high-pressure xenon gas time projection chamber that will search for the neutrinoless double beta decay of Xe-136. The detector possesses two features of great value in neutrinoless double beta decay searches: very good energy resolution (better than 1% FWHM at the Q value of Xe-136) and track reconstruction for the discrimination of signal and background events. This combination results in excellent sensitivity, as discussed in this paper. Detailed Monte Carlo detector simulations and material-screening measurements predict a background rate for NEXT-100 of at most 0.0004 counts/(keV kg yr). Accordingly, the detector will reach a sensitivity to the neutrinoless double beta decay half-life of 6.E25 years after running for 3 effective years.

  3. Decay Spectroscopy for Nuclear Astrophysics: {beta}-delayed Proton Decay

    Energy Technology Data Exchange (ETDEWEB)

    Trache, L.; Simmons, E.; Spiridon, A.; McCleskey, M.; Roeder, B. T.; Tribble, R. E. [Texas A and M University, College Station, TX 77845 (United States); Saastamoinen, A.; Jokinen, A.; Aysto, J. [University of Jyvaskyla, Jyvaskyla (Finland); Davinson, T.; Woods, P. J. [University of Edinburgh, Edinburgh (United Kingdom); Pollacco, E.; Kebbiri, M. [CEA/IRFU Saclay (France); Pascovici, G. [IKP, Universitaet zu Koeln (Germany)

    2011-11-30

    Decay spectroscopy is one of the oldest indirect methods in nuclear astrophysics. We have developed at TAMU techniques to measure beta- and beta-delayed proton decay of sd-shell, proton-rich nuclei. The short-lived radioactive species are produced in-flight, separated, then slowed down (from about 40 MeV/u) and implanted in the middle of very thin Si detectors. These allowed us to measure protons with energies as low as 200 keV from nuclei with lifetimes of 100 ms or less. At the same time we measure gamma-rays up to 8 MeV with high resolution HPGe detectors. We have studied the decay of {sup 23}Al, {sup 27}P, {sup 31}Cl, all important for understanding explosive H-burning in novae. The technique has shown a remarkable selectivity to beta-delayed charged-particle emission and works even at radioactive beam rates of a few pps. The states populated are resonances for the radiative proton capture reactions {sup 22}Na(p,{gamma}){sup 23}Mg(crucial for the depletion of {sup 22}Na in novae), {sup 26m}Al(p,{gamma}){sup 27}Si and {sup 30}P(p,{gamma}){sup 31}S(bottleneck in novae and XRB burning), respectively. More recently we have radically improved the technique using a gas based detector we call AstroBox.

  4. Development of a radiofrequency linear ion trap for {beta} decay study

    Energy Technology Data Exchange (ETDEWEB)

    Li, G. [McGill Univ., Montreal, Quebec (Canada); Argonne National Laboratory, Argonne, Illinois (United States); Scielzo, N.D. [Lawrence Livermore National Laboratory, Livermore, California (United States); Segel, R.E. [Northwestern Univ., Illinois (United States); and others

    2010-07-01

    A Beta decay Paul Trap (BPT) has been constructed at Argonne National Laboratory for the precise measurement of beta decay. We have demonstrated the capability of producing and transferring a low-energy, bunched, and isotopically pure ions beam. In BPT the ions are cooled to sub-eV energies, and confined in a volume of less than 1 mm{sup 3}. The trap has an open geometry which allows four sets of radiation detectors covering a substantial potion of solid angle. In combination with versatile detectors, BPT is able to precisely determine the entire decay kinematics of many isotopes. (author)

  5. Beta decay of polarized nuclei and the decay asymmetry of 8Li

    International Nuclear Information System (INIS)

    Bigelow, R.; Freedman, S.J.; Napolitano, J.; Quin, P.A.

    1985-01-01

    Under certain conditions, it is possible to produce vector-polarized radioactive nuclei in reactions with a polarized projectile and an unpolarized target. Using the intense polarized beams at the University of Wisconsin, the authors have begun a program to study the weak interaction through the beta decay of polarized nuclei produced in this way. Such experiments bear on tests of CVC in light nuclei, sensitive searches for second-class weak currents, and measurements of the weak vector-coupling constant. One may also deduce the values of certain matrix elements. Our effort is presently centering on a study of the energy dependence of the beta-decay asymmetry of 8 Li

  6. Tables of double beta decay data

    Energy Technology Data Exchange (ETDEWEB)

    Tretyak, V.I. [AN Ukrainskoj SSR, Kiev (Ukraine)]|[Strasbourg-1 Univ., 67 (France). Centre de Recherches Nucleaires; Zdesenko, Y.G. [AN Ukrainskoj SSR, Kiev (Ukraine)

    1995-12-31

    A compilation of experimental data on double beta decay is presented. The tables contain the most stringent known experimental limits or positive results of 2{beta} transitions of 69 natural nuclides to ground and excited states of daughter nuclei for different channels (2{beta}{sup -}; 2{beta}{sup +}; {epsilon}{beta}{sup +}; 2{epsilon}) and modes (0{nu}; 2{nu}; 0{nu}M) of decay. (authors). 189 refs., 9 figs., 3 tabs.

  7. Sigma beta decay

    International Nuclear Information System (INIS)

    Newman, D.E.

    1975-01-01

    Describes an experiment to measure beta decays of the sigma particle. Sigmas produced by stopping a K - beam in a liquid hydrogen target decayed in the following reactions: Kp → Σπ; Σ → Neν. The electron and pion were detected by wire spark chambers in a magnetic spectrometer and by plastic scintillators, and were differentiated by a threshold gas Cherenkov counter. The neutron was detected by liquid scintillation counters. The data (n = 3) shell electrons or the highly excited electrons decay first. Instead, it is suggested that when there are two to five electrons in highly excited states immediately after a heavy ion--atom collision the first transitions to occur will be among highly excited Rydberg states in a cascade down to the 4s, 4p, and 3d-subshells. If one of the long lived states becomes occupied by electrons promoted during the collision or by electrons falling from higher levels, it will not decay until after the valence shell decays. LMM rates calculated to test the methods used are compared to previous works. The mixing coefficients are given in terms of the states 4s4p, 45sp+-, and 5s5p. The applicability of Cooper, Fano, and Prats' discussion of the energies and transition rates of doubly excited states is considered

  8. Theoretical aspects of double beta decay

    International Nuclear Information System (INIS)

    Haxton, W.C.

    1984-01-01

    Considerable effort has been expended recently in theoretical studies of double beta decay. Much of this work has focussed on the constraints this process places on gauge theories of the weak interaction, in general, and on the neutrino mass matrix, in particular. In addition, interesting nuclear structure questions have arisen in studies of double beta decay matrix elements. After briefly reviewing the theory of double beta decay, some of the progress that has been made in these areas is summarized. 25 references

  9. Nuclear structure and double beta decay

    International Nuclear Information System (INIS)

    Vogel, P.

    1988-01-01

    Double beta decay is a rare transition between two nuclei of the same mass number A involving a change of the nuclear charge Z by two units. It has long been recognized that the Oν mode of double beta decay, where two electrons and no neutrinos are emitted, is a powerful tool for the study of neutrino properties. Its observation would constitute a convincing proof that there exists a massive Majorana neutrino which couples to electrons. Double beta decay is a process involving an intricate mixture of particle physics and physics of the nucleus. The principal nuclear physics issues have to do with the evaluation of the nuclear matrix elements responsible for the decay. If the authors wish to arrive at quantitative answers for the neutrino properties the authors have no choice but to learn first how to understand the nuclear mechanisms. The authors describe first the calculation of the decay rate of the 2ν mode of double beta decay, in which two electrons and two antineutrinos are emitted

  10. Probing new physics models of neutrinoless double beta decay with SuperNEMO

    Energy Technology Data Exchange (ETDEWEB)

    Arnold, R. [CNRS/IN2P3, IPHC, Universite de Strasbourg, Strasbourg (France); Augier, C.; Bongrand, M.; Garrido, X.; Jullian, S.; Sarazin, X.; Simard, L. [CNRS/IN2P3, LAL, Universite Paris-Sud 11, Orsay (France); Baker, J.; Caffrey, A.J.; Horkley, J.J.; Riddle, C.L. [INL, Idaho Falls, ID (United States); Barabash, A.S.; Konovalov, S.I.; Umatov, V.I.; Vanyushin, I.A. [Institute of Theoretical and Experimental Physics, Moscow (Russian Federation); Basharina-Freshville, A.; Evans, J.J.; Flack, R.; Holin, A.; Kauer, M.; Richards, B.; Saakyan, R.; Thomas, J.; Vasiliev, V.; Waters, D. [University College London, London (United Kingdom); Brudanin, V.; Egorov, V.; Kochetov, O.; Nemchenok, I.; Timkin, V.; Tretyak, V.; Vasiliev, R. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Cebrian, S.; Dafni, T.; Irastorza, I.G.; Gomez, H.; Iguaz, F.J.; Luzon, G.; Rodriguez, A. [University of Zaragoza, Zaragoza (Spain); Chapon, A.; Durand, D.; Guillon, B.; Mauger, F. [Universite de Caen, LPC Caen, ENSICAEN, Caen (France); Chauveau, E.; Hubert, P.; Hugon, C.; Lutter, G.; Marquet, C.; Nachab, A.; Nguyen, C.H.; Perrot, F.; Piquemal, F.; Ricol, J.S. [UMR 5797, Universite de Bordeaux, Centre d' Etudes Nucleaires de Bordeaux Gradignan, Gradignan (France); UMR 5797, CNRS/IN2P3, Centre d' Etudes Nucleaires de Bordeaux Gradignan, Gradignan (France); Deppisch, F.F.; Jackson, C.M.; Nasteva, I.; Soeldner-Rembold, S. [Univ. of Manchester (United Kingdom); Diaz, J.; Monrabal, F.; Serra, L.; Yahlali, N. [CSIC - Univ. de Valencia, IFIC (Spain); Fushima, K.I. [Tokushima Univ., Tokushima (Japan); Holy, K.; Povinec, P.P.; Simkovic, F. [Comenius Univ., FMFI, Bratislava (Slovakia); Ishihara, N. [KEK, Tsukuba, Ibaraki (Japan); Kovalenko, V. [CNRS/IN2P3, IPHC, Univ. de Strasbourg (France); Joint Inst. for Nuclear Research, Dubna (Russian Federation); Lamhamdi, T. [USMBA, Fes (Morocco); Lang, K.; Pahlka, R.B. [Univ. of Texas, Austin, TX (United States)] (and others)

    2010-12-15

    The possibility to probe new physics scenarios of light Majorana neutrino exchange and right-handed currents at the planned next generation neutrinoless double {beta} decay experiment SuperNEMO is discussed. Its ability to study different isotopes and track the outgoing electrons provides the means to discriminate different underlying mechanisms for the neutrinoless double {beta} decay by measuring the decay half-life and the electron angular and energy distributions. (orig.)

  11. Improved limits on beta(-) and beta(-) decays of Ca-48

    Czech Academy of Sciences Publication Activity Database

    Bakalyarov, A.; Balysh, A.; Barabash, AS.; Beneš, P.; Briancon, C.; Brudanin, V. B.; Čermák, P.; Egorov, V.; Hubert, F.; Hubert, P.; Korolev, NA.; Kosjakov, VN.; Kovalík, Alojz; Lebedev, NA.; Novgorodov, A. F.; Rukhadze, NI.; Štekl, NI.; Timkin, VV.; Veleshko, IE.; Vylov, T.; Umatov, VI.

    2002-01-01

    Roč. 76, č. 9 (2002), s. 545-547 ISSN 0021-3640 Institutional research plan: CEZ:AV0Z1048901 Keywords : beta decay * double beta decay * Ca-48 Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 1.483, year: 2002

  12. Induced nuclear beta decay

    International Nuclear Information System (INIS)

    Reiss, H.R.

    1986-01-01

    Certain nuclear beta decay transitions normally inhibited by angular momentum or parity considerations can be induced to occur by the application of an electromagnetic field. Such decays can be useful in the controlled production of power, and in fission waste disposal

  13. PandaX-III neutrinoless double beta decay experiment

    Science.gov (United States)

    Wang, Shaobo; PandaX-III Collaboration

    2017-09-01

    The PandaX-III experiment uses high pressure Time Projection Chambers (TPCs) to search for neutrinoless double-beta decay of Xe-136 with high energy resolution and sensitivity at the China Jin-Ping underground Laboratory II (CJPL-II). Fine-pitch Microbulk Micromegas will be used for charge amplification and readout in order to reconstruct both the energy and track of the neutrinoless double-beta decay event. In the first phase of the experiment, the detector, which contains 200 kg of 90% Xe-136 enriched gas operated at 10 bar, will be immersed in a large water tank to ensure 5 m of water shielding. For the second phase, a ton-scale experiment with multiple TPCs will be constructed to improve the detection probability and sensitivity. A 20-kg scale prototype TPC with 7 Micromegas modules has been built to optimize the design of Micromegas readout module, study the energy calibration of TPC and develop algorithm of 3D track reconstruction.

  14. Possible test of grand unification in the double beta-decay

    International Nuclear Information System (INIS)

    Faessler, A.

    1988-01-01

    The more successful grand unified theories predict that the neutrino is identical with its antiparticle and therefore is a Majorana neutrino which violates lepton number conservation. Such a neutrino should have a finite mass and also a small right handed weak interaction. If the double neutrinoless beta decay is observed with the full decay energy in the two electrons, it would establish that the electron neutrino is a Majorana particle. It is shown that the relativistic corrections of the nucleonic wave functions are essential for determining an upper limit of the right handedness from the measured lower limit of the life-time against the neutrinoless double beta decay. The upper limit for the right handedness of the weak interaction derived from the lower limit of the life-times against the neutrinoless beta decay is vertical stroke vertical stroke -8 and the upper limit for the neutrino mass is vertical stroke ν m>vertical stroke + -decay in proton rich nuclei, one can explain the long standing puzzle of the quenching of the Gamow-Teller strength in agreement with the data. (orig.)

  15. Isospin and quarks in nuclear beta-decay

    International Nuclear Information System (INIS)

    Wilkinson, D.H.

    1991-04-01

    This paper exposes in some detail the technical problems relating to the extraction of the vector coupling constant from the beta decay of complex nuclei. It also considers the extraction of the axial coupling constant from the beta-decay of the neutron. The internal consistency of all data relating to beta-decay, including that of the muon, is also examined, within the standard model, with a view to the possible intervention of W R . (Author) 52 refs., 4 figs., 2 tabs

  16. Majorana neutrinos and double beta-decay

    International Nuclear Information System (INIS)

    Shchepkin, M.G.

    1986-01-01

    Problem, related to neutrino mass and lepton charge L conservation is briefly discussed. A possibility to experimentally test L conservation in different processes and to produce limitations for neutrino mass in double beta-decay processes is considered. Planned experiments on studying the double neutrinoless (2β) beta-decays and searching 2β(2ν)-decays, permitted by the conservation laws, are discussed. It is stressed, that comparison of the existing theoretical predictions of 2β(2ν)-decay probability with experimental results will make it possible to choose the most adequate approach to the calculation of double β-transition nuclear amplitudes

  17. Structure of $^{191}$Pb from $\\alpha$- and $\\beta$-decay spectroscopy

    CERN Document Server

    Cocolios, T E; Van de Walle, J; Franchoo, S; Marsh, B A; Sjoedin, A M; Huyse, M; Zemlyanoy, S; Cocolios, T E; Bastin, B; Barzakh, A; Page, R D; Mane, E; Van Duppen, P; Darby, I G; Venhart, M; Kudryavtsev, Yu; Huber, G; Fedosseev, V N; Andreyev, A N; Keupers, M; Flanagan, K T; Stefan, I; Dexters, W; Koester, U; Antalic, S; Buscher, J; Molkanov, P; Fedorov, D V

    2010-01-01

    Complementary studies of $^{191}$Pb have been made in the $\\beta$- decay of $^{191}$Bi at LISOL (CRC) and in the $\\alpha$- decay of $^{195}$Po at ISOLDE (CERN). Fine structures in the $\\alpha$- decay of the low-spin and high-spin isomers of $^{195}$Po have been fully resolved. Identification of the parent state is made possible via isomer selection based on narrow-band laser frequency scanning. The $\\alpha$-particle and $\\gamma$-ray energies have been determined with greater precision. New $\\alpha$-particle and $\\gamma$-ray energies are identified. Branching ratios in the decay of $^{195}$Po and $^{191}$Pb have been examined.

  18. Review of modern double beta decay experiments

    Science.gov (United States)

    Barabash, A. S.

    2015-10-01

    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 T1/2(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 ( at the level of ˜ 0.01-0.1 eV are discussed.

  19. Double Charge Exchange Reactions and Double Beta Decay

    Science.gov (United States)

    Auerbach, N.

    2018-05-01

    The subject of this presentation is at the forefront of nuclear physics, namely double beta decay. In particular one is most interested in the neutrinoless process of double beta decay, when the decay proceeds without the emission of two neutrinos. The observation of such decay would mean that the lepton conservation symmetry is violated and that the neutrinos are of Majorana type, meaning that they are their own anti-particles. The life time of this process has two unknowns, the mass of the neutrino and the nuclear matrix element. Determining the nuclear matrix element and knowing the cross-section well will set limits on the neutrino mass. There is a concentrated effort among the nuclear physics community to calculate this matrix element. Usually these matrix elements are a very small part of the total strength of the transition operators involved in the process. There is no simple way to “calibrate” the nuclear double beta decay matrix element. The double beta decay is a double charge exchange process, therefore it is proposed that double charge exchange reactions using ion projectiles on nuclei that are candidates for double beta decay, will provide additional necessary information about the nuclear matrix elements.

  20. Precision study of the $\\beta$-decay of $^{74}$Rb

    CERN Multimedia

    Van Duppen, P L E; Lunney, D

    2002-01-01

    We are proposing a high-resolution study of the $\\beta$-decay of $^{74}$Rb in order to extrapolate our precision knowledge of the superallowed $\\beta$-decays from the sd and fp shells towards the medium-heavy Z=N nuclei. The primary goal is to provide new data for testing the CVC hypothesis and the unitarity condition of the CKM matrix of the Standard Model. The presented programme would involve the careful measurements of the decay properties of $^{74}$Rb including the branching ratios to the excited states as well as the precise determination of the decay energy of $^{74}$Rb. The experimental methods readily available at ISOLDE include high-transmission conversion electron spectroscopy, $\\gamma$-ray spectroscopy as well as the measurements of the masses of $^{74}$Rb and $^{74}$Kr using two complementary techniques, ISOLTRAP and MISTRAL. The experiment would rely on a high-quality $^{74}$Rb beam available at ISOLDE with adequate intensity.

  1. Beta decay of 72Co and excited levels in 72Ni

    International Nuclear Information System (INIS)

    Grzywacz, R.; Rykaczewski, K.; Sawicka, M.; Pfuetzner, M.; Daugas, J.M.; Belier, G.; Sauvestre, J.E.; Meot, V.; Roig, O.; Giovinazzo, J.; Grawe, H.; Mayet, P.; Matea, I.; Georgiev, G.; Lewitowicz, M.; Olivieira, F. de; Stodel, C.; Saint-Laurent, M. G.; Stanoiu, M.; Verney, D.

    2003-01-01

    An experiment was performed at GANIL to observe isomeric- and beta-delayed gamma rays from very neutron-rich nuclei around 74Ni. Fragmentation products of the 86Kr beam at 58 AMeV were studied using new devices: the LISE 2000 spectrometer and detectors from the EXOGAM germanium array. The primary aim of the experiment was to find the 8+ microsecond isomer in 76Ni and to perform beta decay spectroscopy of Co nuclei. We have successfully measured the beta delayed gammas from the decay of 72Co to 72Ni. The energies for the lowest excited states in 72Ni are proposed, with the first 2+ state at 1096 keV. These findings suggest a solution of the problem of the disappearance of the 8+ isomer in 72Ni. We also measured beta decay of other neutron-rich Co isotopes including 70Co. First evidence was found for a new short lived isomer, most likely the Iπ=8+ state, in 76Ni

  2. Beta decay heat following U-235, U-238 and Pu-239 neutron fission

    Science.gov (United States)

    Li, Shengjie

    1997-09-01

    This is an experimental study of beta-particle decay heat from 235U, 239Pu and 238U aggregate fission products over delay times 0.4-40,000 seconds. The experimental results below 2s for 235U and 239Pu, and below 20s for 238U, are the first such results reported. The experiments were conducted at the UMASS Lowell 5.5-MV Van de Graaff accelerator and 1-MW swimming-pool research reactor. Thermalized neutrons from the 7Li(p,n)7Be reaction induced fission in 238U and 239Pu, and fast neutrons produced in the reactor initiated fission in 238U. A helium-jet/tape-transport system rapidly transferred fission fragments from a fission chamber to a low background counting area. Delay times after fission were selected by varying the tape speed or the position of the spray point relative to the beta spectrometer that employed a thin-scintillator-disk gating technique to separate beta-particles from accompanying gamma-rays. Beta and gamma sources were both used in energy calibration. Based on low-energy(energies 0-10 MeV. Measured beta spectra were unfolded for their energy distributions by the program FERD, and then compared to other measurements and summation calculations based on ENDF/B-VI fission-product data performed on the LANL Cray computer. Measurements of the beta activity as a function of decay time furnished a relative normalization. Results for the beta decay heat are presented and compared with other experimental data and the summation calculations.

  3. Neutrinoless Double Beta Decay Experiments

    International Nuclear Information System (INIS)

    Garfagnini, A.

    2014-08-01

    Neutrinoless double beta decay is the only process known so far able to test the neutrino intrinsic nature: its experimental observation would imply that the lepton number is violated by two units and prove that neutrinos have a Majorana mass components, being their own anti-particle. While several experiments searching for such a rare decay have been per- formed in the past, a new generation of experiments using different isotopes and techniques have recently released their results or are taking data and will provide new limits, should no signal be observed, in the next few years to come. The present contribution reviews the latest public results on double beta decay searches and gives an overview on the expected sensitivities of the experiments in construction which will be able to set stronger limits in the near future. EXO and KamLAND-Zen experiments are based on the decay of Xe 136 , GERDA and MAJORANA experiments are based on the decay of Ge 76 , and the CUORE experiment is based on the decay of Te 130

  4. Review of modern double beta decay experiments

    Energy Technology Data Exchange (ETDEWEB)

    Barabash, A. S., E-mail: barabash@itep.ru [Institute of Theoretical and Experimental Physics (NRC ”Kurchatov Institute”), B. Cheremushkinskaya 25, Moscow (Russian Federation)

    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.

  5. Relativistic pn-QRPA to the double beta decay

    International Nuclear Information System (INIS)

    Conti, Claudio de; Krmpotic, F.; Carlson, Brett Vern

    2010-01-01

    Full text: In nature there are about 50 nuclear systems where the single beta-decay is energetically forbidden, and double- beta decay turns out to be only possible mode of disintegration. It is the nuclear pairing force which causes such an 'anomaly', by making the mass of the odd-odd isobar, (N - 1;Z + 1), to be greater than the masses of its even-even neighbors, (N;Z) and (N - 2;Z +2). The modes by which the double-beta decay can take place are connected with the neutrino and antineutrino distinction. In case the lepton number is strictly conserved the neutrino is a Dirac fermion and the two-neutrino mode is the only possible mode of disintegration. On the other hand, if this conservation is violated, the neutrino is a Majorana particle and neutrinoless double-beta decay also can occur. Both two-neutrino and neutrinoless double-beta decay processes have attracted much attention, because a comparison between experiment and theory for the first, provides a measure of confidence one may have in the nuclear wave function employed for extracting the unknown parameters from neutrinoless lifetime measurements. The proton-neutron (pn) quasiparticle random phase approximation (QRPA) has turned out be the most simple model for calculating the nuclear wave function involved in the double-beta decay transitions. In this work the transition matrix elements for 0 + -> 0 + double-beta decay are calculated for 48 Ca, 76 Ge, 82 Se, 100 Mo, 128 Te and 130 Te nuclei, using a relativistic pn-QRPA based on Hartree-Bogoliubov approximation to the single-particle motion. (author)

  6. Double beta decay of 82Se

    International Nuclear Information System (INIS)

    Elliott, S.R.; Hahn, A.A.; Moe, M.K.; Nelson, M.A.; Vient, M.A.

    1992-01-01

    The two-neutrino double beta decay of 82 Se has been measured during a 20 244 h run resulting in a half-life of 1.08 -0.06 +0.26 x10 20 years (68% C.L.). No candidate events for the zero-neutrino double beta decay during 21 924 h results in a half-life limit of 2.7x10 22 years at the 68% confidence level

  7. Relativistic pn-QRPA to the double beta decay

    International Nuclear Information System (INIS)

    Conti, Claudio de; Krmpotic, Francisco; Carlson, Brett Vern

    2011-01-01

    Full text: In nature there are about 50 nuclear systems where the single beta-decay is energetically forbidden, and double-beta decay turns out to be only possible mode of disintegration. It is the nuclear pairing force which causes such an 'anomaly', by making the mass of the odd-odd isobar, (N - 1;Z + 1), to be greater than the masses of its even-even neighbors, (N;Z) and (N - 2;Z +2). The modes by which the double-beta decay can take place are connected with the neutrino and antineutrino distinction. In case the lepton number is strictly conserved the neutrino is a Dirac fermion and the two-neutrino mode is the only possible mode of disintegration. On the other hand, if this conservation is violated, the neutrino is a Majorana particle and neutrinoless double-beta decay also can occur. Both two-neutrino and neutrinoless double-beta decay processes have attracted much attention, because a comparison between experiment and theory for the first, provides a measure of confidence one may have in the nuclear wave function employed for extracting the unknown parameters from neutrinoless lifetime measurements. The proton-neutron (pn) quasiparticle random phase approximation (QRPA) has turned out be the most simple model for calculating the nuclear wave function involved in the double-beta decay transitions. In this work the transition matrix elements for 0 + → 0 + double-beta decay are calculated for 48 Ca, 76 Ge, 82 Se, 100 Mo, 128 Te and 130 Te nuclei, using a relativistic pn-QRPA based on Hartree-Bogoliubov approximation to the single-particle motion. (author)

  8. Beta decay of highly charged ions

    International Nuclear Information System (INIS)

    Litvinov, Yuri A; Bosch, Fritz

    2011-01-01

    Beta decay of highly charged ions has attracted much attention in recent years. An obvious motivation for this research is that stellar nucleosynthesis proceeds at high temperatures where the involved atoms are highly ionized. Another important reason is addressing decays of well-defined quantum-mechanical systems, such as one-electron ions where all interactions with other electrons are excluded. The largest modifications of nuclear half-lives with respect to neutral atoms have been observed in beta decay of highly charged ions. These studies can be performed solely at ion storage rings and ion traps, because there high atomic charge states can be preserved for extended periods of time (up to several hours). Currently, all experimental results available in this field originate from experiments at the heavy-ion complex GSI in Darmstadt. There, the fragment separator facility FRS allows the production and separation of exotic, highly charged nuclides, which can then be stored and investigated in the storage ring facility ESR. In this review, we present and discuss in particular two-body beta decays, namely bound-state beta decay and orbital electron capture. Although we focus on experiments conducted at GSI, we will also attempt to provide general requirements common to any other experiment in this context. Finally, we address challenging but not yet performed experiments and we give prospects for the new radioactive beam facilities, such as FAIR in Darmstadt, IMP in Lanzhou and RIKEN in Wako.

  9. Beta decay of 22O

    International Nuclear Information System (INIS)

    Hubert, F.; Dufour, J.P.; Del Moral, R.; Fleury, A.; Jean, D.; Pravikoff, M.S.; Geissel, H.; Schmidt, K.H.; Hanelt, E.

    1989-01-01

    The study of light nuclei far from stability has been recently renewed by the possibility of production through the projectile fragmentation of intermediate energy heavy ion beams at GANIL. The results presented here have been obtained with the Projectile Fragments Isotopic Separation method developed at the LISE spectrometer. 22 O is a Tz = 3 nucleus and is the first in a series of seven such nuclei in the sd shell extending from 22 O to 24 Mg. Although the half life of 22 O was previously measured by Murphy et al., the present study is the first beta-gamma spectroscopy on this neutron rich nucleus. Five gamma lines have been attributed to the β decay of 22 O with a measured half life of T = (2.25±0.15)s and a partial decay scheme has been established

  10. Can $\\beta$-decay probe excited state halos?

    CERN Multimedia

    2002-01-01

    In the first experiment at the newly constructed ISOLDE Facility the first-forbidden $\\beta$-decay of $^{17}$Ne into the first excited state of $^{17}$F has been measured. It is a factor two faster than the corresponding mirror decay and thus gives one of the largest recorded asymmetries for $\\beta$-decays feeding bound final states. Shell-model calculations can only reproduce the asymmetry if the halo structure of the $^{17}$F state is taken into account.

  11. Precision measurements in nuclear beta decay

    Energy Technology Data Exchange (ETDEWEB)

    Naviliat-Cuncic, Oscar, E-mail: naviliat@nscl.msu.edu [Michigan State University, National Superconducting Cyclotron Laboratory and Department of Physics and Astronomy (United States)

    2013-03-15

    Precision measurements in nuclear beta decay provide sensitive means to determine the fundamental coupling of charged fermions to weak bosons and to test discrete symmetries in the weak interaction. The main motivation of such measurements is to find deviations from Standard Model predictions as possible indications of new physics. I focus here on two topics related to precision measurements in beta decay, namely: (i) the determination of the V{sub ud} element of the Cabibbo-Kobayashi-Maskawa quark mixing matrix from nuclear mirror transitions and (ii) selected measurements of time reversal violating correlations in nuclear and neutron decays. These topics complement those presented in other contributions to this conference.

  12. Molecular effects in the neutrino mass determination from beta-decay of the tritium molecule

    International Nuclear Information System (INIS)

    Fackler, O.; Jeziorski, B.; Kolos, W.; Szalewicz, K.; Monkhorst, H.J.; Mugge, M.

    1986-03-01

    Molecular final state energies and transition probabilities have been computed for beta-decay of the tritium molecule. The results are of sufficient accuracy to make a determination of the electron neutrino rest mass with an error not exceeding a few tenths of an electron volt. Effects of approximate models of tritium beta-decay on the neutrino mass determination are discussed. 14 refs., 3 figs., 1 tab

  13. The 76Ge Program to Search for Neutrinoless Double-Beta Decay

    Science.gov (United States)

    Guiseppe, Vincente

    2017-09-01

    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 and Gerda Collaborations are operating arrays of high purity Ge detectors to search for neutrinoless double-beta decay in 76Ge. The Majorana Demonstrator is operating at the Sanford Underground Research Facility in South Dakota while the Gerda experiment is operating at LNGS in Italy. The Gerda and Majorana Demonstrator experiments have achieved the lowest backgrounds in the neutrinoless double-beta decay region of interest. These results, coupled with the superior energy resolution (0.1%) of Ge detectors demonstrate that 76Ge is an ideal isotope for a large next generation experiment. The LEGEND collaboration, with 220 members from 47 institutions around the world, has been formed to pursue a ton scale 76Ge experiment. Building on the successes of Gerda and Majorana, the LEGEND collaboration aims to develop a phased neutrinoless double-beta decay experimental program with discovery potential at a half-life significantly longer than 1027 years. This talk will present the initial results from the Majorana Demonstrator and Gerda experiments and the plan for the LEGEND program.

  14. Introductory remarks on double beta decay and nuclear physics

    International Nuclear Information System (INIS)

    Rosen, S.P.

    1986-01-01

    The particle physics aspects of double beta decay and the theory of the phenomenon are briefly reviewed. The distinction between Dirac and Majorana neutrinos is drawn by comparing the neutrino that accompanies a negatively charged lepton in some hadronic decay process with that which accompanies a positively charged lepton in some other decay process. Two modes of double beta decay are examined - one emitting two neutrinos and the other emitting no neutrinos. What can be learned from the existing data on double beta decay is considered, de-emphasizing the question of bounds on neutrino mass and concentrating on the properties of the phenomenon itself. Possible future experiments are anticipated. 16 refs

  15. Double beta decay: experiments

    International Nuclear Information System (INIS)

    Fiorini, Ettore

    2006-01-01

    The results obtained so far and those of the running experiments on neutrinoless double beta decay are reviewed. The plans for second generation experiments, the techniques to be adopted and the expected sensitivities are compared and discussed

  16. Double beta decay: A theoretical overview

    International Nuclear Information System (INIS)

    Rosen, S.P.

    1988-01-01

    This paper reviews the theoretical possibility of double beta decay. The titles of the main sections of this paper are: Nuclear physics setting; Particle physics requirements; Kinematical features of the decay modes; Nuclear matrix elements; the Shell model and two-neutrino decay; Quasi-particle random phase approximation; and Future considerations. 18 refs., 7 tabs

  17. Nuclear aspects of double-beta decay

    International Nuclear Information System (INIS)

    Stoica, S.; Paun, V.

    2002-01-01

    Calculations of the neutrinoless double-beta decay (0νββ) matrix elements are performed with the second quasi random phase approximation (SQRPA) method for several nuclei. The results display a weak dependence on the single particle basis used and the Ikeda sum rule is fulfilled with good accuracy. Comparing our calculations with similar ones performed with other QRPA-based methods we estimate the accuracy of these methods in the prediction of the (0νββ) decay matrix elements and neutrino mass parameter, which is settled to about 50% from their calculated values. Taking the most recent experimental limits for the neutrinoless double beta decay half-lives, we also deduced new limits for the neutrino mass parameter. (authors)

  18. Beta decay of Cu-56

    NARCIS (Netherlands)

    Borcea, R; Aysto, J; Caurier, E; Dendooven, P; Doring, J; Gierlik, M; Gorska, M; Grawe, H; Hellstrom, M; Janas, Z; Jokinen, A; Karny, M; Kirchner, R; La Commara, M; Langanke, K; Martinez-Pinedo, G; Mayet, P; Nieminen, A; Nowacki, F; Penttila, H; Plochocki, A; Rejmund, M; Roeckl, E; Schlegel, C; Schmidt, K; Schwengner, R; Sawicka, M

    2001-01-01

    The proton-rich isotope Cu-56 was produced at the GSI On-Line Mass Separator by means of the Si-28(S-32, p3n) fusion-evaporation reaction. Its beta -decay properties were studied by detecting beta -delayed gamma rays and protons. A half-Life of 93 +/- 3 ms was determined for Cu-56. Compared to the

  19. Why search for double beta decay?

    International Nuclear Information System (INIS)

    Kayser, B.

    1988-01-01

    Searching for neutrinoless double beta decay is the only known practical method for trying to determine whether neutrinos are their own antiparticles. The theoretical motivation for supposing that they may indeed be their own antiparticles is described. The reason that it is so difficult to ascertain experimentally whether they are or are not is explained, as is the special sensitivity of neutrinoless double beta decay. The potential implications of the observation of this reaction for neutrino mass and for the physics of neutrinos is discussed

  20. Beta-decay of {sup 56}Cu

    Energy Technology Data Exchange (ETDEWEB)

    Ramdhane, M.; Baumann, P.; Knipper, A.; Walter, G. [Institute de Recherches Subatomiques, 67 - Strasbourg (France); Janas, Z.; Plochocki, A. [Warsaw Univ. (Poland). Inst. of Experimental Physics; Aeystoe, J.; Dendooven, P.; Jokinen, A.; Oinonen, M.; Pentilae, H. [Jyvaeskylae Univ. (Finland); Liu, W.; Grawe, H.; Hu, Z.; Kirchner, R.; Klepper, O.; Roeckl, E. [Gesellschaft fuer Schwerionenforschung mbH, Darmstadt (Germany); Gorska, M. [Warsaw Univ. (Poland). Inst. of Experimental Physics]|[Gesellschaft fuer Schwerionenforschung mbH, Darmstadt (Germany); Fujita, Y. [Osaka Univ. (Japan); Brown, B.A. [Michigan State Univ., East Lansing, MI (United States)

    1998-02-01

    By measuring positrons and {beta}-delayed {gamma}-rays emitted from mass-separated sources, the decay of {sup 56}Cu(4{sup +},T{sub z}=-1,T=1) to states in the doubly-magic nucleus {sup 56}Ni was studied for the first time. The half-life of {sup 56}Cu was measured to be 78(15) ms, and four {beta}-delayed {gamma}-rays were assigned to its decay. The resulting experimental data on Fermi and Gamow-Teller strength are compared with shell-model predictions. (orig.)

  1. Search for Neutrinoless Double-Beta Decay

    OpenAIRE

    Tornow, Werner

    2014-01-01

    After the pioneering work of the Heidelberg-Moscow (HDM) and International Germanium Experiment (IGEX) groups, the second round of neutrinoless double-$\\beta$ decay searches currently underway has or will improve the life-time limits of double-$\\beta$ decay candidates by a factor of two to three, reaching in the near future the $T_{1/2} = 3 \\times 10^{25}$ yr level. This talk will focus on the large-scale experiments GERDA, EXO-200, and KamLAND-Zen, which have reported already lower half-life...

  2. ${\\beta}$-decay studies of neutron-rich $^{61-70}$Mn isotopes with the new LISOL ${\\beta}$-decay setup

    CERN Multimedia

    Diriken, J V J

    2008-01-01

    The aim of this proposal is to gather new information that will serve as benchmark to test shell model calculations in the region below $^{68}$Ni, where proper residual interactions are still under development. More specifically, the ${\\beta}$-decay experiment of the $^{61-70}$Mn isotopes will highlight the development of collectivity in the Fe isotopes and its daughters. At ISOLDE, neutron-rich Mn isotopes are produced with a UC$_{x}$ target and selective laser ionization. These beams are particularly pure and reasonable yields are obtained for the neutron-rich short lived $^{61-70}$Mn isotopes. We propose to perform ${\\beta}$-decay studies on $^{61-70}$Mn utilizing the newly-developed "LISOL ${\\beta}$-decay setup", consisting of two MINIBALL cluster Ge detectors and a standard tape station. The use of digital electronics in the readout of these detectors enables us to perform a "slow correlation technique" which should indicate the possible existence of isomers in the daughter nuclei.

  3. Simulated progress in double-beta decay

    International Nuclear Information System (INIS)

    Miley, H.S.; Arthur, R.J.; Avignone, F.T.

    1993-09-01

    A Monte Carlo code has been developed to accurately simulate double-beta decay measurements. Coincident gamma rays, beta spectra, and angular correlations have been added to adequately simulate a complete 100 Mo nuclear decay and provide corrections to experimentally determined detector efficiencies. This code has been used to strip certain low-background spectra obtained in the Homestake gold mine in Lead, SD, for the purpose of extremely sensitive materials assay for the construction of new, large, enriched germanium detectors. Assays as low as 9 μBq/g of 210 Pb in lead shielding were obtained

  4. Measurement of the two neutrino double beta decay half-life of Zr-96 with the NEMO-3 detector

    Energy Technology Data Exchange (ETDEWEB)

    Argyriades, J. [LAL, Universite Paris-Sud 11, CNRS/IN2P3, F-91405 Orsay (France); Arnold, R. [IPHC, Universite de Strasbourg, CNRS/IN2P3, F-67037 Strasbourg (France); Augier, C. [LAL, Universite Paris-Sud 11, CNRS/IN2P3, F-91405 Orsay (France); Baker, J. [INL, Idaho National Laboratory, 83415 Idaho Falls (United States); Barabash, A.S. [ITEP, Institute of Theoretical and Experimental Physics, 117259 Moscow (Russian Federation); Basharina-Freshville, A. [University College London, WC1E 6BT London (United Kingdom); Bongrand, M. [LAL, Universite Paris-Sud 11, CNRS/IN2P3, F-91405 Orsay (France); Broudin-Bay, G. [Universite Bordeaux, CENBG, UMR 5797, F-33175 Gradignan (France); CNRS/IN2P3, Centre d' Etudes Nucleaires de Bordeaux Gradignan, UMR5797, F-33175 Gradignan (France); Brudanin, V. [JINR, Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Caffrey, A.J. [INL, Idaho National Laboratory, 83415 Idaho Falls (United States); Chapon, A. [LPC, ENSICAEN, Universite de Caen, CNRS/IN2P3, F-14032 Caen (France); Chauveau, E. [Universite Bordeaux, CENBG, UMR 5797, F-33175 Gradignan (France); CNRS/IN2P3, Centre d' Etudes Nucleaires de Bordeaux Gradignan, UMR5797, F-33175 Gradignan (France); Daraktchieva, Z. [University College London, WC1E 6BT London (United Kingdom); Durand, D. [LPC, ENSICAEN, Universite de Caen, CNRS/IN2P3, F-14032 Caen (France); Egorov, V. [JINR, Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Fatemi-Ghomi, N. [University of Manchester, M13 9PL Manchester (United Kingdom); Flack, R. [University College London, WC1E 6BT London (United Kingdom); Guillon, B. [LPC, ENSICAEN, Universite de Caen, CNRS/IN2P3, F-14032 Caen (France); Hubert, Ph. [Universite Bordeaux, CENBG, UMR 5797, F-33175 Gradignan (France); CNRS/IN2P3, Centre d' Etudes Nucleaires de Bordeaux Gradignan, UMR5797, F-33175 Gradignan (France); Jullian, S. [LAL, Universite Paris-Sud 11, CNRS/IN2P3, F-91405 Orsay (France)

    2010-12-08

    Using 9.4 g of {sup 96}Zr isotope and 1221 days of data from the NEMO-3 detector corresponding to 0.031 kg y, the obtained 2{nu}{beta}{beta} decay half-life measurement is T{sub 1/2}{sup 2{nu}=}[2.35{+-}0.14(stat){+-}0.16(syst)]x10{sup 19} yr. Different characteristics of the final state electrons have been studied, such as the energy sum, individual electron energy, and angular distribution. The 2{nu} nuclear matrix element is extracted using the measured 2{nu}{beta}{beta} half-life and is M{sup 2{nu}=}0.049{+-}0.002. Constraints on 0{nu}{beta}{beta} decay have also been set.

  5. Evaluation of beta-decay III. The complex gamma function

    International Nuclear Information System (INIS)

    Wilkinson, D.H.

    1993-05-01

    Two real, analytical, approximations for the square of the modulus of the complex gamma function as it appears in F(Z, W), the Fermi function for beta-decay, are evaluated; an accuracy bettering 10 -4 % can easily be achieved for all electron energies throughout the periodic table. (author). 3 refs., 1 tab., 7 figs

  6. Nuclear Matrix Elements for the $\\beta\\beta$ Decay of the $^{76}$Ge

    CERN Document Server

    Brown, B A; Horoi, M

    2015-01-01

    The nuclear matrix elements for two-neutrino double-beta (2 n$\\beta\\beta$ ) and zero-neutrino double-beta (0 n$\\beta\\beta$) decay of 76 Ge are evaluated in terms of the configuration interaction (CI), quasiparticle random phase approximation (QRPA) and interacting boson model (IBM) methods. We show that the decomposition of the matrix elements in terms of interemediate states in 74 Ge is dominated by ground state of this nucleus. We consider corrections to the CI results that arise from configurations admixtures involving orbitals out-side of the CI configuration space by using results from QRPA, many-body-perturbation theory, and the connections to related observables. The CI two-neutrino matrix element is reduced due to the inclusion of spin-orbit partners, and to many-body correlations connected with Gamow-Teller beta decay. The CI zero-neutrino matrix element for the heavy neutrino is enhanced due to particle-particle correlations that are connected with the odd-even oscillations in the nuclear masse...

  7. Beta decay and rhenium cosmochronology

    International Nuclear Information System (INIS)

    Ashktorab, K.

    1992-01-01

    Among the problems which limit the use of the 187 Re/ 187 Os isobaric pair as a cosmochronometer for the age of the galaxy and the universe are the uncertainties in the partial half-lives of the continuum and bound state decays of 187 Re. While the total half-life of the decay is well established, the partial half-life for the continuum decay is uncertain, and several measurements are not compatible. A high temperature quartz proportional counter was used in this work to remeasure the continuum β - decay of 187 Re. The β endpoint energy for the decay of neutral 187 Re to singly ionized 187 Os of 2.75 ± 0.06 keV agrees with the earlier results. The corresponding half-life of (45 ± 3) x 10 9 years improves and agrees with the earlier measurement of Payne and Drever and refutes other measurements. Based on the new half-life for the continuum decay and a total half-life of (43.5 ± 1.3) x 10 9 years reported by Linder et al., the branching ratio for the bound state decay into discrete atomic states is estimated to be (3 ± 6)% in agreement with the most recent calculated theoretical branching ratio of approximately 1%. Anomalies in beta spectra reported by J.J. Simpson and others have been attributed to a 17 keV heavy-neutrino admixture. If confirmed, the implications from the existence of such a neutrino for particle and astrophysics would be significant. A multiwire open-quotes wall-lessclose quotes stainless steel proportional counter has been used in the present work to investigate the spectral shape of the β decay of 63 Ni. No anomalies in the spectral shape were observed which could be attributed to the presence of 17 keV heavy neutrino

  8. Meson exchange currents and two neutrino double beta decay

    International Nuclear Information System (INIS)

    Simkovic, F.

    1995-01-01

    By using a field theory approach a detailed analysis of the two neutrino double beta decay amplitude has been performed. We have shown that the summation over the intermediate nuclear states in the present two neutrino double beta decay studies corresponds to a summation over a class of meson exchange diagrams. We offer some arguments showing that the two nucleon mechanism considered at present does not provide the main contribution to the two neutrino double beta decay amplitude. A new electron-gamma exchange mechanism for this process is suggested. 31 refs., 1 fig

  9. Is neutrinoless double beta decay suppressed

    International Nuclear Information System (INIS)

    Tomoda, T.

    1989-01-01

    Much effort has been devoted to the study of nuclear double beta decay, since the observation of a neutrinoless double beta (OνΒΒ) decay would be clear evidence that the electron neutrino is a Majorana particle. The OνΒΒ decay is caused by a finite Majorana neutrino mass and/or an admixture of right-handed leptonic currents. In order to relate these quantities to OνΒΒ decay rates, we need nuclear matrix elements, which are model dependent. One of the possibilities of testing nuclear models employed in such analysis is to calculate the experimentally known rates of ΒΒ decay with emission of two neutrinos (2νΒΒ decay) which occurs independently of the nature of the neutrino. There was a long-standing difficulty in such attempts that the calculated 2νΒΒ decay rates turned out to be always too large by one to two orders of magnitude. Trying to overcome such difficulty, Klapdor and Grotz as well as Vogel and Zirnbauer showed in their calculation using schematic effective interactions such that 2νΒΒ decay rates can get reduced considerably due to the nuclear ground state correlations. This paper reports that the suppression is ascribed to that of the virtual Gamow-Teller transitions from the excited 1 + states of the intermediate odd-odd -even nucleus

  10. Experiments on double beta decay

    Energy Technology Data Exchange (ETDEWEB)

    Busto, J [Neuchatel Univ. (Switzerland). Inst. de Physique

    1996-11-01

    The Double Beta Decay, and especially ({beta}{beta}){sub 0{nu}} mode, is an excellent test of Standard Model as well as of neutrino physics. From experimental point of view, a very large number of different techniques are or have been used increasing the sensitivity of this experiments quite a lot (the factor of 10{sup 4} in the last 20 years). In future, in spite of several difficulties, the sensitivity would be increased further, keeping the interest of this very important process. (author) 4 figs., 5 tabs., 21 refs.

  11. A study of beta decay energies and atomic masses

    International Nuclear Information System (INIS)

    Spanier, L.

    1988-04-01

    The q β energies of 123-131 In have been determined using the end points of β spectra recorded in β-γ coincidence experiments. A HPGe planar detector was used to detect the β-particles and a semi-empirical response function was used when unfolding the electron distribution. The mass excesses were deduced and when they were compared with the predictions of various mass formulae, the cadmium isotopes were found to be heavier than those predicted by most of the mass formulae. The excitation energy of the 1/2 - proton-hole state in the odd indium isotopes was shown to be constant for all the heavy isotopes. The Q EC energies of 148 Dy and 96 Pd were determined using the β + /EC intensity ratio method. The ratio of the intensity of the β+ branch to the total beta decay intensity was determined by means of γ-spectroscopic methods. The mass excesses were deduced. The two-proton binding energy for the N=82 isotones showed only a small step of approximately 0.5 MeV when the doubly-magic nucleus 146 Gd was encountered. A liquid drop type mass formula with deformation and shell energy corrections and with few free parameters is presented. The shell energy correction is a simple analytical expression for the equilibrium deformation of the nucleus. An analytical expression for the equilibrium nuclear deformation is also presented. The mass formula was applied to nuclei with Z and N greater than 50. The RMS deviation is 0.55 milli mass units. The reaction 98 Mo(p,n) 98 Tc was investigated through the counter ratio method, the ratio of the number of slow neutrons to the number of fast neutrons. The Q pn energy value of a low-spin state in 98 Tc was determined. The state at 90.9 keV excitation energy is proposed to be the 14.6 m u s isomer and have spin and parity 1 + . (author)

  12. Study of the $\\beta$-decay of $^{20}$Mg

    CERN Multimedia

    Cederkall, J A; Riisager, K; Garcia borge, M J; Madurga flores, M; Jonson, B N G; Fynbo, H O U; Koldste, G T; Giles, T J; Nilsson, T; Perea martinez, A

    We propose to perform a detailed study of the $\\beta$-decay of the dripline nucleus $^{20}$Mg. This will provide important information on resonances in $^{20}$Na relevant for the astrophysical rp-process as well as improved information for detailed comparison with state-of-the-art Shell-Model calculations and for comparison with the mirror $\\beta$-decay of $^{20}$O.

  13. Beta-delayed proton decay of 73Sr

    International Nuclear Information System (INIS)

    Batchelder, J.C.; Moltz, D.M.; Ognibene, T.J.; Rowe, M.W.; Tighe, R.J.; Cerny, J.

    1993-01-01

    The T z =-3/2, A=4n+1 nuclide 73 Sr produced in the 40 Ca( 36 Ar,3n) reaction has been observed via beta-delayed proton emission. A single proton group at a laboratory energy of 3.75±0.04 MeV has been observed, corresponding to decay of the T=3/2 isobaric analog state in 73 Rb to the ground state of 72 Kr. Combining this measurement with a Coulomb displacement energy calculation yields a mass excess for 73 Sr of -31.82±0.24 MeV based on a predicted mass for 72 Kr of -53.94±0.24 MeV

  14. The beta(+) decay and cosmic-ray half-life of Mn-54

    Science.gov (United States)

    Dacruz, M. T. F.; Norman, E. B.; Chan, Y. D.; Garcia, A.; Larimer, R. M.; Lesko, K. T.; Stokstad, R. G.; Wietfeldt, F. E.

    1993-03-01

    We performed a search for the beta(+) branch of Mn-54 decay. As a cosmic ray, Mn-54, deprived of its atomic electrons, can decay only via beta(+) and beta(-) decay, with a half-life of the order of 106 yr. This turns Mn-54 into a suitable cosmic chronometer for the study of cosmic-ray confinement times. We searched for coincident back-to-back 511-keV gamma-rays using two germanium detectors inside a Nal(Tl) annulus. An upper limit of 2 x 10-8 was found for the beta(+) decay branch, corresponding to a lower limit of 13.7 for the log ft value.

  15. The N=82 gap in /sup 146/Gd from beta -decay studies of Tb isotopes

    CERN Document Server

    Styczen, J; Kleinheinz, P; Piiparinen, M

    1981-01-01

    The beta -decay study of 23 s /sup 146/Tb suggests a ( pi h/sub 11/2/ nu d/sup -1//sub 3/2/) 5/sup -/ configuration for this activity. In its decay the authors have identified a pi h/sub 11/2/ to nu h/sub 9/2 / GT decay branch which populates neutron particle-hole states in /sup 146/Gd. Hence the N=82 single particle energy gap is less than 4 MeV. Neutron one-particle two-hole and two-particle one-hole states in /sup 145/Gd and /sup 147/Gd were identified in the beta -decays of 29 s /sup 145/Tb and 1.6 h /sup 147/Tb. (11 refs).

  16. Grand unification and the double beta-decay

    International Nuclear Information System (INIS)

    Faessler, A.

    1992-01-01

    Models of the unification of the electroweak and the strong interaction predict that the neutrino is a Majorana particle and therefore essentially identical with its own antiparticle. In such grand unified models the neutrino has also a finite mass and a slight right-handed weak interaction, since the model is left-right symmetric. These models have also left handed and right-handed vector bosons to mediate the weak interactions. If these models are correct the neutrinoless double beta-decay is feasable. Thus if one finds the neutrinoless double beta-decay one knows that the standard model can not be correct in which the neutrino is a Dirac particle and therefore different from its antiparticle. Although the neutrinoless double beta-decay has not been seen it is possible to extract from the lower limits of the lifetime against the double neutrinoless beta-decay upper limits for the effective electron-neutrino mass and for the effective mixing angle of the right-handed and the left-handed vector bosons mediating the weak interaction. One also can obtain an effective upper limit for the mass ratio of the light and the heavy vector bosons. The extraction of this physical quantities from the data is made difficult due to the fact that the weak interaction must not be diagonal in the representation of the mass matrix of the six neutrinos requested by such left-right symmetric models. (author)

  17. On the Proton Spectrum in Free Neutron beta-decay

    CERN Document Server

    Bunatian, G G

    2000-01-01

    We consider the calculations which are appropriate to acquire with a high precision, of ~1% or better, the general characteristics of weak interactions from the experiments on the free neutron beta-decay; the principle emphasis is placed on the phenomena associated with the recoil of protons. The part played by electromagnetic interactions in beta-decay is visualized, with special attention drawn to the influence of the gamma-radiation on the momentum distribution of the particles in the final state. The effect of electromagnetic interactions on the proton recoil spectrum is studied, in the light of the experiments which are carried out and planned for now. The results of the calculations, which are to be confronted with the experimental data, are presented upright in terms of the effective Lagrangian underlying the inquiry. Owing to electromagnetic interactions, the corrections to the energy distribution of protons prove to amount to the value of a few per cent. Nowadays, this is substantial to obtain with a...

  18. The majorana {sup 76}Ge double-beta decay project

    Energy Technology Data Exchange (ETDEWEB)

    Aalseth, C.E.; Adles, E.; Anderson, D.; Avignone, F.T.; Barabash, A.; Bowyer, T.W.; Brodzinski, R.L.; Brudanin, V.; Champangne, A.; Collar, J.I.; Doe, P.J.; Egorov, S.; Elliott, S.R.; Farach, H.A.; Gaitskell, R.; Jordan, D.; Jain, R.K.; Kazkaz, K.; King, G.; Kochetov, O.; Konovalov, S.; Kouzes, R.; Miley, H.S.; Palms, J.M.; Pitts, W.K.; Reeves, J.H.; Robertson, R.G.H.; Rohm, R.; Sandukovsky, S.; Smith, L.E.; Stekhanov, V.; Thompson, R.C.; Tornow, W.; Umatov' , V.; Warner, R.; Webb, J.; Wilkerson, J.F.; Young, A

    2003-07-01

    The interest and relevance of next-generation 0{sub v} {beta}{beta}-decay experiments is increasing. Even with nonzero neutrino mass strongly suggested by solar and atmospheric neutrino experiments sensitive to {delta}m{sup 2}, 0{sub v} {beta}{beta}-decay experiments are still the only way to establish the Dirac or Majorana nature of neutrinos by measuring the effective electron neutrino mass, . In addition, the atmospheric neutrino oscillation experiments imply that at least one neutrino has a mass greater than about 50 meV. The Majorana Experiment expects to probe an effective neutrino mass near this critical value. Majorana is a next-generation {sup 76}Ge double-beta decay search. It will employ 500 kg of Ge, isotopically enriched to 86% in {sup 76}Ge, in the form of {approx} 200 detectors in a close-packed array. Each crystal will be electronically segmented and each segment fitted with pulse-shape analysis electronics. This combination of segmentation and pulse-shape analysis significantly improves our ability to discriminate neutrinoless double beta-decay from internal cosmogenic {sup 68}Ge and {sup 60}Co. The half-life sensitivity is estimated to be 4.2 x 10{sup 27} y corresponding to a range of {<=} 20 - 70 meV, depending on the nuclear matrix elements used to interpret the data.

  19. Double Beta Decay Experiments

    International Nuclear Information System (INIS)

    Piepke, A.

    2005-01-01

    The experimental observation of neutrino oscillations and thus neutrino mass and mixing gives a first hint at new particle physics. The absolute values of the neutrino mass and the properties of neutrinos under CP-conjugation remain unknown. The experimental investigation of the nuclear double beta decay is one of the key techniques for solving these open problems

  20. Search for new physics with neutrinoless double beta decay

    International Nuclear Information System (INIS)

    Klapdor-Kleingrothaus, H.V.; Baudis, L.; Hellmig, J.; Hirsch, M.; Kolb, S.; Paes, H.; Ramachers, Y.

    1999-01-01

    Neutrinoless double beta decay (0νββ) is one of the most sensitive approaches to test particle physics beyond the standard model. During the last years, besides the most restrictive limit on the effective Majorana neutrino mass, the analysis of new contributions by the Heidelberg group led to bounds on left-right-symmetric models, leptoquarks and R-parity violating models competitive to recent accelerator limits, which are of special interest in view of the HERA anomaly at large Q 2 and x. These new results deduced from the Heidelberg-Moscow double beta decay experiment are reviewed. Also an outlook on the future of double beta decay, the GENIUS proposal, is given

  1. On the nuclear double beta decay: microscopic description

    International Nuclear Information System (INIS)

    Civitarese, Osvaldo

    1989-01-01

    This paper is devoted to the discussion of some problems related with microscopic descriptions of the nuclear double beta decay. It has been organized in the following order: 1) Review of the experimental situation; 2) Brief discussion of the theoretical aspects related to the current algebra, weak interaction, neutrino and majoron's status and 3) Elements of the standard nuclear theory involved in the calculation of transition densities for the nuclear double beta decay. (Author) [es

  2. Beta decay of the fission product 125Sb and a new complete evaluation of absolute gamma ray transition intensities

    Science.gov (United States)

    Rajput, M. U.; Ali, N.; Hussain, S.; Mujahid, S. A.; MacMahon, D.

    2012-04-01

    The radionuclide 125Sb is a long-lived fission product, which decays to 125Te by negative beta emission with a half-life of 1008 day. The beta decay is followed by the emission of several gamma radiations, ranging from low to medium energy, that can suitably be used for high-resolution detector calibrations, decay heat calculations and in many other applications. In this work, the beta decay of 125Sb has been studied in detail. The complete published experimental data of relative gamma ray intensities in the beta decay of the radionuclide 125Sb has been compiled. The consistency analysis was performed and discrepancies found at several gamma ray energies. Evaluation of the discrepant data was carried out using Normalized Residual and RAJEVAL methods. The decay scheme balance was carried out using beta branching ratios, internal conversion coefficients, populating and depopulating gamma transitions to 125Te levels. The work has resulted in the consistent conversion factor equal to 29.59(13) %, and determined a new evaluated set of the absolute gamma ray emission probabilities. The work has also shown 22.99% of the delayed intensity fraction as outgoing from the 58 d isomeric 144 keV energy level and 77.01% of the prompt intensity fraction reaching to the ground state from the other excited states. The results are discussed and compared with previous evaluations. The present work includes additional experimental data sets which were not included in the previous evaluations. A new set of recommended relative and absolute gamma ray emission probabilities is presented.

  3. Beta decay of the fission product 125Sb and a new complete evaluation of absolute gamma ray transition intensities

    International Nuclear Information System (INIS)

    Rajput, M.U.; Ali, N.; Hussain, S.; Mujahid, S.A.; MacMahon, D.

    2012-01-01

    The radionuclide 125 Sb is a long-lived fission product, which decays to 125 Te by negative beta emission with a half-life of 1008 day. The beta decay is followed by the emission of several gamma radiations, ranging from low to medium energy, that can suitably be used for high-resolution detector calibrations, decay heat calculations and in many other applications. In this work, the beta decay of 125 Sb has been studied in detail. The complete published experimental data of relative gamma ray intensities in the beta decay of the radionuclide 125 Sb has been compiled. The consistency analysis was performed and discrepancies found at several gamma ray energies. Evaluation of the discrepant data was carried out using Normalized Residual and RAJEVAL methods. The decay scheme balance was carried out using beta branching ratios, internal conversion coefficients, populating and depopulating gamma transitions to 125 Te levels. The work has resulted in the consistent conversion factor equal to 29.59(13) %, and determined a new evaluated set of the absolute gamma ray emission probabilities. The work has also shown 22.99% of the delayed intensity fraction as outgoing from the 58 d isomeric 144 keV energy level and 77.01% of the prompt intensity fraction reaching to the ground state from the other excited states. The results are discussed and compared with previous evaluations. The present work includes additional experimental data sets which were not included in the previous evaluations. A new set of recommended relative and absolute gamma ray emission probabilities is presented.

  4. Double-beta decay processes from lattice quantum chromodynamics

    Science.gov (United States)

    Davoudi, Zohreh; Tiburzi, Brian; Wagman, Michael; Winter, Frank; Chang, Emmanuel; Detmold, William; Orginos, Kostas; Savage, Martin; Shanahan, Phiala; Nplqcd Collaboration

    2017-09-01

    While an observation of neutrinoless double-beta decay in upcoming experiments will establish that the neutrinos are Majorana particles, the underlying new physics responsible for this decay can only be constrained if the theoretical predictions of the rate are substantially refined. This talk demonstrates the roadmap in connecting the underlying high-scale theory to the corresponding nuclear matrix elements, focusing mainly on the nucleonic matrix elements in the simplest extension of Standard Model in which a light Majorana neutrino is mediating the process. The role of lattice QCD and effective field theory in this program, in particular, the prospect of a direct matching of the nn to pp amplitude to lattice QCD will be discussed. As a first step towards this goal, the results of the first lattice QCD calculation of the relevant matrix element for neutrinofull double-beta decay will be presented, albeit with unphysical quark masses, along with important lessons that could impact the calculations of nuclear matrix elements involved in double-beta decays of realistic nuclei.

  5. T-odd momentum correlation in radiative {beta} decay

    Energy Technology Data Exchange (ETDEWEB)

    Gardner, Susan, E-mail: gardner@pa.uky.edu; He, Daheng [University of Kentucky, Department of Physics and Astronomy (United States)

    2013-03-15

    The triple-product correlations observable in ordinary neutron or nuclear beta decay are all naively T violating and can connect, through an assumption of CPT invariance, to constraints on sources of CP violation beyond the Standard Model. They are also spin dependent. In this context the study of radiative beta decay opens a new possibility, in that a triple-product correlation can be constructed from momenta alone. Consequently its measurement would constrain new spin-independent sources of CP violation. We will describe these in light of the size of the triple momentum correlation in the decay rate arising from electromagnetic final-state interactions in the Standard Model. Our expression for the corresponding T-odd asymmetry is exact in O({alpha}) up to terms of recoil order, and we evaluate it numerically under various kinematic conditions. We consider the pattern of the asymmetries in nuclear {beta} decays and show that the asymmetry can be suppressed in particular cases, facilitating searches for new sources of CP violation in such processes.

  6. Properties of low-lying intruder states in $^{34}$Al and $^{34}$Si sequentially populated in $\\beta$-decay of $^{34}$Mg

    CERN Multimedia

    A low-lying long-lived (26±1 ms) isomer in $^{34}$Al has been observed recently and assigned as 1$^{+}$ state of intruder character. It was populated in $^{36}$S fragmentation and feeds, in $\\beta$-decay, the 0$_{2}^{+}$ state in $^{34}$Si whose excitation energy and lifetime were determined in an electron-positron pairs spectroscopy experiment. In the present experiment we intend to measure for the first time the $\\gamma$-rays following the $\\beta$-decay of $^{34}$Mg. Despite the interest for $^{34}$Mg, the up-right corner of the “N$\\thicksim$20 island of inversion”, the only information on its $\\beta$-decay is the lifetime of 20±10 ms, determined from $\\beta$-neutron coincidences. As a result of the proposed experiment, we expect to place the first transitions in the level scheme of $^{34}$Al and to strongly populate the newly observed isomer, measuring its excitation energy, if the branching ratio to 4$^{−}$ ground state is significant. Theoretical estimations for the $\\beta$-decay of the new isome...

  7. Combining and comparing neutrinoless double beta decay experiments using different nuclei

    Science.gov (United States)

    Bergström, Johannes

    2013-02-01

    We perform a global fit of the most relevant neutrinoless double beta decay experiments within the standard model with massive Majorana neutrinos. Using Bayesian inference makes it possible to take into account the theoretical uncertainties on the nuclear matrix elements in a fully consistent way. First, we analyze the data used to claim the observation of neutrinoless double beta decay in 76Ge, and find strong evidence (according to Jeffrey's scale) for a peak in the spectrum and moderate evidence for that the peak is actually close to the energy expected for the neutrinoless decay. We also find a significantly larger statistical error than the original analysis, which we include in the comparison with other data. Then, we statistically test the consistency between this claim with that of recent measurements using 136Xe. We find that the two data sets are about 40 to 80 times more probable under the assumption that they are inconsistent, depending on the nuclear matrix element uncertainties and the prior on the smallest neutrino mass. Hence, there is moderate to strong evidence of incompatibility, and for equal prior probabilities the posterior probability of compatibility is between 1.3% and 2.5%. If one, despite such evidence for incompatibility, combines the two data sets, we find that the total evidence of neutrinoless double beta decay is negligible. If one ignores the claim, there is weak evidence against the existence of the decay. We also perform approximate frequentist tests of compatibility for fixed ratios of the nuclear matrix elements, as well as of the no signal hypothesis. Generalization to other sets of experiments as well as other mechanisms mediating the decay is possible.

  8. Beta-delayed neutron decay of $^{33}$Na

    CERN Document Server

    Radivojevic, Z; Caurier, E; Cederkäll, J; Courtin, S; Dessagne, P; Jokinen, A; Knipper, A; Le Scornet, G; Lyapin, V G; Miehé, C; Nowacki, F; Nummela, S; Oinonen, M; Poirier, E; Ramdhane, M; Trzaska, W H; Walter, G; Äystö, J

    2002-01-01

    Beta-delayed neutron decay of /sup 33/Na has been studied using the on-line mass separator ISOLDE. The delayed neutron spectra were measured by time-of-flight technique using fast scintillators. Two main neutron groups at 800(60) and 1020(80) keV were assigned to the /sup 33/Na decay, showing evidence for strong feeding of states at about 4 MeV in /sup 33/Mg. By simultaneous beta - gamma -n counting the delayed neutron emission probabilities P/sub 1n/ = 47(6)% and P /sub 2n/ = 13(3)% were determined. The half-life value for /sup 33 /Na, T/sub 1/2/ = 8.0(3) ms, was measured by three different techniques, one employing identifying gamma transitions and two employing beta and neutron counting. (21 refs).

  9. Determination of $\\gamma$ and $-2\\beta_s$ from charmless two-body decays of beauty mesons

    CERN Document Server

    Aaij, Roel; Adeva, Bernardo; Adinolfi, Marco; Affolder, Anthony; Ajaltouni, Ziad; Akar, Simon; Albrecht, Johannes; Alessio, Federico; Alexander, Michael; Ali, Suvayu; Alkhazov, Georgy; Alvarez Cartelle, Paula; Alves Jr, Antonio Augusto; Amato, Sandra; Amerio, Silvia; Amhis, Yasmine; An, Liupan; Anderlini, Lucio; Anderson, Jonathan; Andreassen, Rolf; Andreotti, Mirco; Andrews, Jason; Appleby, Robert; Aquines Gutierrez, Osvaldo; Archilli, Flavio; Artamonov, Alexander; Artuso, Marina; Aslanides, Elie; Auriemma, Giulio; Baalouch, Marouen; Bachmann, Sebastian; Back, John; Badalov, Alexey; Baesso, Clarissa; Baldini, Wander; Barlow, Roger; Barschel, Colin; Barsuk, Sergey; Barter, William; Batozskaya, Varvara; Battista, Vincenzo; Bay, Aurelio; Beaucourt, Leo; Beddow, John; Bedeschi, Franco; Bediaga, Ignacio; Belogurov, Sergey; Belous, Konstantin; Belyaev, Ivan; Ben-Haim, Eli; Bencivenni, Giovanni; Benson, Sean; Benton, Jack; Berezhnoy, Alexander; Bernet, Roland; Bettler, Marc-Olivier; van Beuzekom, Martinus; Bien, Alexander; Bifani, Simone; Bird, Thomas; Bizzeti, Andrea; Bjørnstad, Pål Marius; Blake, Thomas; Blanc, Frédéric; Blouw, Johan; Blusk, Steven; Bocci, Valerio; Bondar, Alexander; Bondar, Nikolay; Bonivento, Walter; Borghi, Silvia; Borgia, Alessandra; Borsato, Martino; Bowcock, Themistocles; Bowen, Espen Eie; Bozzi, Concezio; Brambach, Tobias; Bressieux, Joël; Brett, David; Britsch, Markward; Britton, Thomas; Brodzicka, Jolanta; Brook, Nicholas; Brown, Henry; Bursche, Albert; Busetto, Giovanni; Buytaert, Jan; Cadeddu, Sandro; Calabrese, Roberto; Calvi, Marta; Calvo Gomez, Miriam; Campana, Pierluigi; Campora Perez, Daniel; Carbone, Angelo; Carboni, Giovanni; Cardinale, Roberta; Cardini, Alessandro; Carson, Laurence; Carvalho Akiba, Kazuyoshi; Casse, Gianluigi; Cassina, Lorenzo; Castillo Garcia, Lucia; Cattaneo, Marco; Cauet, Christophe; Cenci, Riccardo; Charles, Matthew; Charpentier, Philippe; Chefdeville, Maximilien; Chen, Shanzhen; Cheung, Shu-Faye; Chiapolini, Nicola; Chrzaszcz, Marcin; Ciba, Krzystof; Cid Vidal, Xabier; Ciezarek, Gregory; Clarke, Peter; Clemencic, Marco; Cliff, Harry; Closier, Joel; Coco, Victor; Cogan, Julien; Cogneras, Eric; Cojocariu, Lucian; Collins, Paula; Comerma-Montells, Albert; Contu, Andrea; Cook, Andrew; Coombes, Matthew; Coquereau, Samuel; Corti, Gloria; Corvo, Marco; Counts, Ian; Couturier, Benjamin; Cowan, Greig; Craik, Daniel Charles; Cruz Torres, Melissa Maria; Cunliffe, Samuel; Currie, Robert; D'Ambrosio, Carmelo; Dalseno, Jeremy; David, Pascal; David, Pieter; Davis, Adam; De Bruyn, Kristof; De Capua, Stefano; De Cian, Michel; De Miranda, Jussara; De Paula, Leandro; De Silva, Weeraddana; De Simone, Patrizia; Decamp, Daniel; Deckenhoff, Mirko; Del Buono, Luigi; Déléage, Nicolas; Derkach, Denis; Deschamps, Olivier; Dettori, Francesco; Di Canto, Angelo; Dijkstra, Hans; Donleavy, Stephanie; Dordei, Francesca; Dorigo, Mirco; Dosil Suárez, Alvaro; Dossett, David; Dovbnya, Anatoliy; Dreimanis, Karlis; Dujany, Giulio; Dupertuis, Frederic; Durante, Paolo; Dzhelyadin, Rustem; Dziurda, Agnieszka; Dzyuba, Alexey; Easo, Sajan; Egorychev, Victor; Eidelman, Semen; Eisenhardt, Stephan; Eitschberger, Ulrich; Ekelhof, Robert; Eklund, Lars; El Rifai, Ibrahim; Elsasser, Christian; Ely, Scott; Esen, Sevda; Evans, Hannah Mary; Evans, Timothy; Falabella, Antonio; Färber, Christian; Farinelli, Chiara; Farley, Nathanael; Farry, Stephen; Fay, Robert; Ferguson, Dianne; Fernandez Albor, Victor; Ferreira Rodrigues, Fernando; Ferro-Luzzi, Massimiliano; Filippov, Sergey; Fiore, Marco; Fiorini, Massimiliano; Firlej, Miroslaw; Fitzpatrick, Conor; Fiutowski, Tomasz; Fol, Philip; Fontana, Marianna; Fontanelli, Flavio; Forty, Roger; Francisco, Oscar; Frank, Markus; Frei, Christoph; Frosini, Maddalena; Fu, Jinlin; Furfaro, Emiliano; Gallas Torreira, Abraham; Galli, Domenico; Gallorini, Stefano; Gambetta, Silvia; Gandelman, Miriam; Gandini, Paolo; Gao, Yuanning; García Pardiñas, Julián; Garofoli, Justin; Garra Tico, Jordi; Garrido, Lluis; Gaspar, Clara; Gauld, Rhorry; Gavardi, Laura; Gavrilov, Gennadii; Geraci, Angelo; Gersabeck, Evelina; Gersabeck, Marco; Gershon, Timothy; Ghez, Philippe; Gianelle, Alessio; Gianì, Sebastiana; Gibson, Valerie; Giubega, Lavinia-Helena; Gligorov, Vladimir; Göbel, Carla; Golubkov, Dmitry; Golutvin, Andrey; Gomes, Alvaro; Gotti, Claudio; Grabalosa Gándara, Marc; Graciani Diaz, Ricardo; Granado Cardoso, Luis Alberto; Graugés, Eugeni; Graziani, Giacomo; Grecu, Alexandru; Greening, Edward; Gregson, Sam; Griffith, Peter; Grillo, Lucia; Grünberg, Oliver; Gui, Bin; Gushchin, Evgeny; Guz, Yury; Gys, Thierry; Hadjivasiliou, Christos; Haefeli, Guido; Haen, Christophe; Haines, Susan; Hall, Samuel; Hamilton, Brian; Hampson, Thomas; Han, Xiaoxue; Hansmann-Menzemer, Stephanie; Harnew, Neville; Harnew, Samuel; Harrison, Jonathan; He, Jibo; Head, Timothy; Heijne, Veerle; Hennessy, Karol; Henrard, Pierre; Henry, Louis; Hernando Morata, Jose Angel; van Herwijnen, Eric; Heß, Miriam; Hicheur, Adlène; Hill, Donal; Hoballah, Mostafa; Hombach, Christoph; Hulsbergen, Wouter; Hunt, Philip; Hussain, Nazim; Hutchcroft, David; Hynds, Daniel; Idzik, Marek; Ilten, Philip; Jacobsson, Richard; Jaeger, Andreas; Jalocha, Pawel; Jans, Eddy; Jaton, Pierre; Jawahery, Abolhassan; Jing, Fanfan; John, Malcolm; Johnson, Daniel; Jones, Christopher; Joram, Christian; Jost, Beat; Jurik, Nathan; Kaballo, Michael; Kandybei, Sergii; Kanso, Walaa; Karacson, Matthias; Karbach, Moritz; Karodia, Sarah; Kelsey, Matthew; Kenyon, Ian; Ketel, Tjeerd; Khanji, Basem; Khurewathanakul, Chitsanu; Klaver, Suzanne; Klimaszewski, Konrad; Kochebina, Olga; Kolpin, Michael; Komarov, Ilya; Koopman, Rose; Koppenburg, Patrick; Korolev, Mikhail; Kozlinskiy, Alexandr; Kravchuk, Leonid; Kreplin, Katharina; Kreps, Michal; Krocker, Georg; Krokovny, Pavel; Kruse, Florian; Kucewicz, Wojciech; Kucharczyk, Marcin; Kudryavtsev, Vasily; Kurek, Krzysztof; Kvaratskheliya, Tengiz; La Thi, Viet Nga; Lacarrere, Daniel; Lafferty, George; Lai, Adriano; Lambert, Dean; Lambert, Robert W; Lanfranchi, Gaia; Langenbruch, Christoph; Langhans, Benedikt; Latham, Thomas; Lazzeroni, Cristina; Le Gac, Renaud; van Leerdam, Jeroen; Lees, Jean-Pierre; Lefèvre, Regis; Leflat, Alexander; Lefrançois, Jacques; Leo, Sabato; Leroy, Olivier; Lesiak, Tadeusz; Leverington, Blake; Li, Yiming; Likhomanenko, Tatiana; Liles, Myfanwy; Lindner, Rolf; Linn, Christian; Lionetto, Federica; Liu, Bo; Lohn, Stefan; Longstaff, Iain; Lopes, Jose; Lopez-March, Neus; Lowdon, Peter; Lu, Haiting; Lucchesi, Donatella; Luo, Haofei; Lupato, Anna; Luppi, Eleonora; Lupton, Oliver; Machefert, Frederic; Machikhiliyan, Irina V; Maciuc, Florin; Maev, Oleg; Malde, Sneha; Malinin, Alexander; Manca, Giulia; Mancinelli, Giampiero; Mapelli, Alessandro; Maratas, Jan; Marchand, Jean François; Marconi, Umberto; Marin Benito, Carla; Marino, Pietro; Märki, Raphael; Marks, Jörg; Martellotti, Giuseppe; Martens, Aurelien; Martín Sánchez, Alexandra; Martinelli, Maurizio; Martinez Santos, Diego; Martinez Vidal, Fernando; Martins Tostes, Danielle; Massafferri, André; Matev, Rosen; Mathe, Zoltan; Matteuzzi, Clara; Mazurov, Alexander; McCann, Michael; McCarthy, James; McNab, Andrew; McNulty, Ronan; McSkelly, Ben; Meadows, Brian; Meier, Frank; Meissner, Marco; Merk, Marcel; Milanes, Diego Alejandro; Minard, Marie-Noelle; Moggi, Niccolò; Molina Rodriguez, Josue; Monteil, Stephane; Morandin, Mauro; Morawski, Piotr; Mordà, Alessandro; Morello, Michael Joseph; Moron, Jakub; Morris, Adam Benjamin; Mountain, Raymond; Muheim, Franz; Müller, Katharina; Mussini, Manuel; Muster, Bastien; Naik, Paras; Nakada, Tatsuya; Nandakumar, Raja; Nasteva, Irina; Needham, Matthew; Neri, Nicola; Neubert, Sebastian; Neufeld, Niko; Neuner, Max; Nguyen, Anh Duc; Nguyen, Thi-Dung; Nguyen-Mau, Chung; Nicol, Michelle; Niess, Valentin; Niet, Ramon; Nikitin, Nikolay; Nikodem, Thomas; Novoselov, Alexey; O'Hanlon, Daniel Patrick; Oblakowska-Mucha, Agnieszka; Obraztsov, Vladimir; Oggero, Serena; Ogilvy, Stephen; Okhrimenko, Oleksandr; Oldeman, Rudolf; Onderwater, Gerco; Orlandea, Marius; Otalora Goicochea, Juan Martin; Owen, Patrick; Oyanguren, Maria Arantza; Pal, Bilas Kanti; Palano, Antimo; Palombo, Fernando; Palutan, Matteo; Panman, Jacob; Papanestis, Antonios; Pappagallo, Marco; Pappalardo, Luciano; Parkes, Christopher; Parkinson, Christopher John; Passaleva, Giovanni; Patel, Girish; Patel, Mitesh; Patrignani, Claudia; Pazos Alvarez, Antonio; Pearce, Alex; Pellegrino, Antonio; Pepe Altarelli, Monica; Perazzini, Stefano; Perez Trigo, Eliseo; Perret, Pascal; Perrin-Terrin, Mathieu; Pescatore, Luca; Pesen, Erhan; Petridis, Konstantin; Petrolini, Alessandro; Picatoste Olloqui, Eduardo; Pietrzyk, Boleslaw; Pilař, Tomas; Pinci, Davide; Pistone, Alessandro; Playfer, Stephen; Plo Casasus, Maximo; Polci, Francesco; Poluektov, Anton; Polycarpo, Erica; Popov, Alexander; Popov, Dmitry; Popovici, Bogdan; Potterat, Cédric; Price, Eugenia; Price, Joseph David; Prisciandaro, Jessica; Pritchard, Adrian; Prouve, Claire; Pugatch, Valery; Puig Navarro, Albert; Punzi, Giovanni; Qian, Wenbin; Rachwal, Bartolomiej; Rademacker, Jonas; Rakotomiaramanana, Barinjaka; Rama, Matteo; Rangel, Murilo; Raniuk, Iurii; Rauschmayr, Nathalie; Raven, Gerhard; Redi, Federico; Reichert, Stefanie; Reid, Matthew; dos Reis, Alberto; Ricciardi, Stefania; Richards, Sophie; Rihl, Mariana; Rinnert, Kurt; Rives Molina, Vincente; Robbe, Patrick; Rodrigues, Ana Barbara; Rodrigues, Eduardo; Rodriguez Perez, Pablo; Roiser, Stefan; Romanovsky, Vladimir; Romero Vidal, Antonio; Rotondo, Marcello; Rouvinet, Julien; Ruf, Thomas; Ruiz, Hugo; Ruiz Valls, Pablo; Saborido Silva, Juan Jose; Sagidova, Naylya; Sail, Paul; Saitta, Biagio; Salustino Guimaraes, Valdir; Sanchez Mayordomo, Carlos; Sanmartin Sedes, Brais; Santacesaria, Roberta; Santamarina Rios, Cibran; Santovetti, Emanuele; Sarti, Alessio; Satriano, Celestina; Satta, Alessia; Saunders, Daniel Martin; Savrie, Mauro; Savrina, Darya; Schiller, Manuel; Schindler, Heinrich; Schlupp, Maximilian; Schmelling, Michael; Schmidt, Burkhard; Schneider, Olivier; Schopper, Andreas; Schune, Marie Helene; Schwemmer, Rainer; Sciascia, Barbara; Sciubba, Adalberto; Seco, Marcos; Semennikov, Alexander; Sepp, Indrek; Serra, Nicola; Serrano, Justine; Sestini, Lorenzo; Seyfert, Paul; Shapkin, Mikhail; Shapoval, Illya; Shcheglov, Yury; Shears, Tara; Shekhtman, Lev; Shevchenko, Vladimir; Shires, Alexander; Silva Coutinho, Rafael; Simi, Gabriele; Sirendi, Marek; Skidmore, Nicola; Skwarnicki, Tomasz; Smith, Anthony; Smith, Edmund; Smith, Eluned; Smith, Jackson; Smith, Mark; Snoek, Hella; Sokoloff, Michael; Soler, Paul; Soomro, Fatima; Souza, Daniel; Souza De Paula, Bruno; Spaan, Bernhard; Sparkes, Ailsa; Spradlin, Patrick; Sridharan, Srikanth; Stagni, Federico; Stahl, Marian; Stahl, Sascha; Steinkamp, Olaf; Stenyakin, Oleg; Stevenson, Scott; Stoica, Sabin; Stone, Sheldon; Storaci, Barbara; Stracka, Simone; Straticiuc, Mihai; Straumann, Ulrich; Stroili, Roberto; Subbiah, Vijay Kartik; Sun, Liang; Sutcliffe, William; Swientek, Krzysztof; Swientek, Stefan; Syropoulos, Vasileios; Szczekowski, Marek; Szczypka, Paul; Szilard, Daniela; Szumlak, Tomasz; T'Jampens, Stephane; Teklishyn, Maksym; Tellarini, Giulia; Teubert, Frederic; Thomas, Christopher; Thomas, Eric; van Tilburg, Jeroen; Tisserand, Vincent; Tobin, Mark; Tolk, Siim; Tomassetti, Luca; Topp-Joergensen, Stig; Torr, Nicholas; Tournefier, Edwige; Tourneur, Stephane; Tran, Minh Tâm; Tresch, Marco; Tsaregorodtsev, Andrei; Tsopelas, Panagiotis; Tuning, Niels; Ubeda Garcia, Mario; Ukleja, Artur; Ustyuzhanin, Andrey; Uwer, Ulrich; Vacca, Claudia; Vagnoni, Vincenzo; Valenti, Giovanni; Vallier, Alexis; Vazquez Gomez, Ricardo; Vazquez Regueiro, Pablo; Vázquez Sierra, Carlos; Vecchi, Stefania; Velthuis, Jaap; Veltri, Michele; Veneziano, Giovanni; Vesterinen, Mika; Viaud, Benoit; Vieira, Daniel; Vieites Diaz, Maria; Vilasis-Cardona, Xavier; Vollhardt, Achim; Volyanskyy, Dmytro; Voong, David; Vorobyev, Alexey; Vorobyev, Vitaly; Voß, Christian; Voss, Helge; de Vries, Jacco; Waldi, Roland; Wallace, Charlotte; Wallace, Ronan; Walsh, John; Wandernoth, Sebastian; Wang, Jianchun; Ward, David; Watson, Nigel; Websdale, David; Whitehead, Mark; Wicht, Jean; Wiedner, Dirk; Wilkinson, Guy; Williams, Matthew; Williams, Mike; Wilschut, Hans; Wilson, Fergus; Wimberley, Jack; Wishahi, Julian; Wislicki, Wojciech; Witek, Mariusz; Wormser, Guy; Wotton, Stephen; Wright, Simon; Wyllie, Kenneth; Xie, Yuehong; Xing, Zhou; Xu, Zhirui; Yang, Zhenwei; Yuan, Xuhao; Yushchenko, Oleg; Zangoli, Maria; Zavertyaev, Mikhail; Zhang, Liming; Zhang, Wen Chao; Zhang, Yanxi; Zhelezov, Alexey; Zhokhov, Anatoly; Zhong, Liang; Zvyagin, Alexander

    2015-01-01

    Using the latest LHCb measurements of time-dependent $C\\!P$ violation in the $B^0_s \\to K^+K^-$ decay, a U-spin relation between the decay amplitudes of $B^0_s \\to K^+K^-$ and $B^0\\to \\pi^+\\pi^-$ decay processes allows constraints to be placed on the angle $\\gamma$ of the unitarity triangle and on the $B^0_s$ mixing phase $-2\\beta_s$. Results from an extended approach, which uses additional inputs on $B^0\\to \\pi^0\\pi^0$ and $B^+\\to \\pi^+\\pi^0$ decays from other experiments and exploits isospin symmetry, are also presented. The dependence of the results on the maximum allowed amount of U-spin breaking is studied. At 68% probability, the value $\\gamma = \\left( 63.5^{\\,+\\, 7.2}_{\\,-\\,6.7} \\right)^\\circ~\\mathrm{modulo}~180^\\circ$ is determined. In an alternative analysis, the value $-2\\beta_s = -0.12 ^{\\,+\\,0.14}_{\\,-\\,0.16}\\,\\,\\mathrm{rad}$ is found. In both measurements, the uncertainties due to U-spin breaking effects up to 50% are included.

  10. Determination of $\\gamma$ and $-2\\beta_s$ from charmless two-body decays of beauty mesons

    CERN Document Server

    Aaij, Roel; Adeva, Bernardo; Adinolfi, Marco; Affolder, Anthony; Ajaltouni, Ziad; Akar, Simon; Albrecht, Johannes; Alessio, Federico; Alexander, Michael; Ali, Suvayu; Alkhazov, Georgy; Alvarez Cartelle, Paula; Alves Jr, Antonio Augusto; Amato, Sandra; Amerio, Silvia; Amhis, Yasmine; An, Liupan; Anderlini, Lucio; Anderson, Jonathan; Andreassen, Rolf; Andreotti, Mirco; Andrews, Jason; Appleby, Robert; Aquines Gutierrez, Osvaldo; Archilli, Flavio; Artamonov, Alexander; Artuso, Marina; Aslanides, Elie; Auriemma, Giulio; Baalouch, Marouen; Bachmann, Sebastian; Back, John; Badalov, Alexey; Baesso, Clarissa; Baldini, Wander; Barlow, Roger; Barschel, Colin; Barsuk, Sergey; Barter, William; Batozskaya, Varvara; Battista, Vincenzo; Bay, Aurelio; Beaucourt, Leo; Beddow, John; Bedeschi, Franco; Bediaga, Ignacio; Belogurov, Sergey; Belous, Konstantin; Belyaev, Ivan; Ben-Haim, Eli; Bencivenni, Giovanni; Benson, Sean; Benton, Jack; Berezhnoy, Alexander; Bernet, Roland; Bettler, Marc-Olivier; van Beuzekom, Martinus; Bien, Alexander; Bifani, Simone; Bird, Thomas; Bizzeti, Andrea; Bjørnstad, Pål Marius; Blake, Thomas; Blanc, Frédéric; Blouw, Johan; Blusk, Steven; Bocci, Valerio; Bondar, Alexander; Bondar, Nikolay; Bonivento, Walter; Borghi, Silvia; Borgia, Alessandra; Borsato, Martino; Bowcock, Themistocles; Bowen, Espen Eie; Bozzi, Concezio; Brambach, Tobias; Bressieux, Joël; Brett, David; Britsch, Markward; Britton, Thomas; Brodzicka, Jolanta; Brook, Nicholas; Brown, Henry; Bursche, Albert; Busetto, Giovanni; Buytaert, Jan; Cadeddu, Sandro; Calabrese, Roberto; Calvi, Marta; Calvo Gomez, Miriam; Campana, Pierluigi; Campora Perez, Daniel; Carbone, Angelo; Carboni, Giovanni; Cardinale, Roberta; Cardini, Alessandro; Carson, Laurence; Carvalho Akiba, Kazuyoshi; Casse, Gianluigi; Cassina, Lorenzo; Castillo Garcia, Lucia; Cattaneo, Marco; Cauet, Christophe; Cenci, Riccardo; Charles, Matthew; Charpentier, Philippe; Chefdeville, Maximilien; Chen, Shanzhen; Cheung, Shu-Faye; Chiapolini, Nicola; Chrzaszcz, Marcin; Ciba, Krzystof; Cid Vidal, Xabier; Ciezarek, Gregory; Clarke, Peter; Clemencic, Marco; Cliff, Harry; Closier, Joel; Coco, Victor; Cogan, Julien; Cogneras, Eric; Cojocariu, Lucian; Collins, Paula; Comerma-Montells, Albert; Contu, Andrea; Cook, Andrew; Coombes, Matthew; Coquereau, Samuel; Corti, Gloria; Corvo, Marco; Counts, Ian; Couturier, Benjamin; Cowan, Greig; Craik, Daniel Charles; Cruz Torres, Melissa Maria; Cunliffe, Samuel; Currie, Robert; D'Ambrosio, Carmelo; Dalseno, Jeremy; David, Pascal; David, Pieter; Davis, Adam; De Bruyn, Kristof; De Capua, Stefano; De Cian, Michel; De Miranda, Jussara; De Paula, Leandro; De Silva, Weeraddana; De Simone, Patrizia; Decamp, Daniel; Deckenhoff, Mirko; Del Buono, Luigi; Déléage, Nicolas; Derkach, Denis; Deschamps, Olivier; Dettori, Francesco; Di Canto, Angelo; Dijkstra, Hans; Donleavy, Stephanie; Dordei, Francesca; Dorigo, Mirco; Dosil Suárez, Alvaro; Dossett, David; Dovbnya, Anatoliy; Dreimanis, Karlis; Dujany, Giulio; Dupertuis, Frederic; Durante, Paolo; Dzhelyadin, Rustem; Dziurda, Agnieszka; Dzyuba, Alexey; Easo, Sajan; Egorychev, Victor; Eidelman, Semen; Eisenhardt, Stephan; Eitschberger, Ulrich; Ekelhof, Robert; Eklund, Lars; El Rifai, Ibrahim; Elsasser, Christian; Ely, Scott; Esen, Sevda; Evans, Hannah Mary; Evans, Timothy; Falabella, Antonio; Färber, Christian; Farinelli, Chiara; Farley, Nathanael; Farry, Stephen; Fay, Robert; Ferguson, Dianne; Fernandez Albor, Victor; Ferreira Rodrigues, Fernando; Ferro-Luzzi, Massimiliano; Filippov, Sergey; Fiore, Marco; Fiorini, Massimiliano; Firlej, Miroslaw; Fitzpatrick, Conor; Fiutowski, Tomasz; Fol, Philip; Fontana, Marianna; Fontanelli, Flavio; Forty, Roger; Francisco, Oscar; Frank, Markus; Frei, Christoph; Frosini, Maddalena; Fu, Jinlin; Furfaro, Emiliano; Gallas Torreira, Abraham; Galli, Domenico; Gallorini, Stefano; Gambetta, Silvia; Gandelman, Miriam; Gandini, Paolo; Gao, Yuanning; García Pardiñas, Julián; Garofoli, Justin; Garra Tico, Jordi; Garrido, Lluis; Gaspar, Clara; Gauld, Rhorry; Gavardi, Laura; Gavrilov, Gennadii; Geraci, Angelo; Gersabeck, Evelina; Gersabeck, Marco; Gershon, Timothy; Ghez, Philippe; Gianelle, Alessio; Gianì, Sebastiana; Gibson, Valerie; Giubega, Lavinia-Helena; Gligorov, V.V.; Göbel, Carla; Golubkov, Dmitry; Golutvin, Andrey; Gomes, Alvaro; Gotti, Claudio; Grabalosa Gándara, Marc; Graciani Diaz, Ricardo; Granado Cardoso, Luis Alberto; Graugés, Eugeni; Graziani, Giacomo; Grecu, Alexandru; Greening, Edward; Gregson, Sam; Griffith, Peter; Grillo, Lucia; Grünberg, Oliver; Gui, Bin; Gushchin, Evgeny; Guz, Yury; Gys, Thierry; Hadjivasiliou, Christos; Haefeli, Guido; Haen, Christophe; Haines, Susan; Hall, Samuel; Hamilton, Brian; Hampson, Thomas; Han, Xiaoxue; Hansmann-Menzemer, Stephanie; Harnew, Neville; Harnew, Samuel; Harrison, Jonathan; He, Jibo; Head, Timothy; Heijne, Veerle; Hennessy, Karol; Henrard, Pierre; Henry, Louis; Hernando Morata, Jose Angel; van Herwijnen, Eric; Heß, Miriam; Hicheur, Adlène; Hill, Donal; Hoballah, Mostafa; Hombach, Christoph; Hulsbergen, Wouter; Hunt, Philip; Hussain, Nazim; Hutchcroft, David; Hynds, Daniel; Idzik, Marek; Ilten, Philip; Jacobsson, Richard; Jaeger, Andreas; Jalocha, Pawel; Jans, Eddy; Jaton, Pierre; Jawahery, Abolhassan; Jing, Fanfan; John, Malcolm; Johnson, Daniel; Jones, Christopher; Joram, Christian; Jost, Beat; Jurik, Nathan; Kaballo, Michael; Kandybei, Sergii; Kanso, Walaa; Karacson, Matthias; Karbach, Moritz; Karodia, Sarah; Kelsey, Matthew; Kenyon, Ian; Ketel, Tjeerd; Khanji, Basem; Khurewathanakul, Chitsanu; Klaver, Suzanne; Klimaszewski, Konrad; Kochebina, Olga; Kolpin, Michael; Komarov, Ilya; Koopman, Rose; Koppenburg, Patrick; Korolev, Mikhail; Kozlinskiy, Alexandr; Kravchuk, Leonid; Kreplin, Katharina; Kreps, Michal; Krocker, Georg; Krokovny, Pavel; Kruse, Florian; Kucewicz, Wojciech; Kucharczyk, Marcin; Kudryavtsev, Vasily; Kurek, Krzysztof; Kvaratskheliya, Tengiz; La Thi, Viet Nga; Lacarrere, Daniel; Lafferty, George; Lai, Adriano; Lambert, Dean; Lambert, Robert W; Lanfranchi, Gaia; Langenbruch, Christoph; Langhans, Benedikt; Latham, Thomas; Lazzeroni, Cristina; Le Gac, Renaud; van Leerdam, Jeroen; Lees, Jean-Pierre; Lefèvre, Regis; Leflat, Alexander; Lefrançois, Jacques; Leo, Sabato; Leroy, Olivier; Lesiak, Tadeusz; Leverington, Blake; Li, Yiming; Likhomanenko, Tatiana; Liles, Myfanwy; Lindner, Rolf; Linn, Christian; Lionetto, Federica; Liu, Bo; Lohn, Stefan; Longstaff, Iain; Lopes, Jose; Lopez-March, Neus; Lowdon, Peter; Lu, Haiting; Lucchesi, Donatella; Luo, Haofei; Lupato, Anna; Luppi, Eleonora; Lupton, Oliver; Machefert, Frederic; Machikhiliyan, Irina V; Maciuc, Florin; Maev, Oleg; Malde, Sneha; Malinin, Alexander; Manca, Giulia; Mancinelli, Giampiero; Mapelli, Alessandro; Maratas, Jan; Marchand, Jean François; Marconi, Umberto; Marin Benito, Carla; Marino, Pietro; Märki, Raphael; Marks, Jörg; Martellotti, Giuseppe; Martens, Aurelien; Martín Sánchez, Alexandra; Martinelli, Maurizio; Martinez Santos, Diego; Martinez Vidal, Fernando; Martins Tostes, Danielle; Massafferri, André; Matev, Rosen; Mathe, Zoltan; Matteuzzi, Clara; Mazurov, Alexander; McCann, Michael; McCarthy, James; McNab, Andrew; McNulty, Ronan; McSkelly, Ben; Meadows, Brian; Meier, Frank; Meissner, Marco; Merk, Marcel; Milanes, Diego Alejandro; Minard, Marie-Noelle; Moggi, Niccolò; Molina Rodriguez, Josue; Monteil, Stephane; Morandin, Mauro; Morawski, Piotr; Mordà, Alessandro; Morello, Michael Joseph; Moron, Jakub; Morris, Adam Benjamin; Mountain, Raymond; Muheim, Franz; Müller, Katharina; Mussini, Manuel; Muster, Bastien; Naik, Paras; Nakada, Tatsuya; Nandakumar, Raja; Nasteva, Irina; Needham, Matthew; Neri, Nicola; Neubert, Sebastian; Neufeld, Niko; Neuner, Max; Nguyen, Anh Duc; Nguyen, Thi-Dung; Nguyen-Mau, Chung; Nicol, Michelle; Niess, Valentin; Niet, Ramon; Nikitin, Nikolay; Nikodem, Thomas; Novoselov, Alexey; O'Hanlon, Daniel Patrick; Oblakowska-Mucha, Agnieszka; Obraztsov, Vladimir; Oggero, Serena; Ogilvy, Stephen; Okhrimenko, Oleksandr; Oldeman, Rudolf; Onderwater, Gerco; Orlandea, Marius; Otalora Goicochea, Juan Martin; Owen, Patrick; Oyanguren, Maria Arantza; Pal, Bilas Kanti; Palano, Antimo; Palombo, Fernando; Palutan, Matteo; Panman, Jacob; Papanestis, Antonios; Pappagallo, Marco; Pappalardo, Luciano; Parkes, Christopher; Parkinson, Christopher John; Passaleva, Giovanni; Patel, Girish; Patel, Mitesh; Patrignani, Claudia; Pazos Alvarez, Antonio; Pearce, Alex; Pellegrino, Antonio; Pepe Altarelli, Monica; Perazzini, Stefano; Perez Trigo, Eliseo; Perret, Pascal; Perrin-Terrin, Mathieu; Pescatore, Luca; Pesen, Erhan; Petridis, Konstantin; Petrolini, Alessandro; Picatoste Olloqui, Eduardo; Pietrzyk, Boleslaw; Pilař, Tomas; Pinci, Davide; Pistone, Alessandro; Playfer, Stephen; Plo Casasus, Maximo; Polci, Francesco; Poluektov, Anton; Polycarpo, Erica; Popov, Alexander; Popov, Dmitry; Popovici, Bogdan; Potterat, Cédric; Price, Eugenia; Price, Joseph David; Prisciandaro, Jessica; Pritchard, Adrian; Prouve, Claire; Pugatch, Valery; Puig Navarro, Albert; Punzi, Giovanni; Qian, Wenbin; Rachwal, Bartolomiej; Rademacker, Jonas; Rakotomiaramanana, Barinjaka; Rama, Matteo; Rangel, Murilo; Raniuk, Iurii; Rauschmayr, Nathalie; Raven, Gerhard; Redi, Federico; Reichert, Stefanie; Reid, Matthew; dos Reis, Alberto; Ricciardi, Stefania; Richards, Sophie; Rihl, Mariana; Rinnert, Kurt; Rives Molina, Vincente; Robbe, Patrick; Rodrigues, Ana Barbara; Rodrigues, Eduardo; Rodriguez Perez, Pablo; Roiser, Stefan; Romanovsky, Vladimir; Romero Vidal, Antonio; Rotondo, Marcello; Rouvinet, Julien; Ruf, Thomas; Ruiz, Hugo; Ruiz Valls, Pablo; Saborido Silva, Juan Jose; Sagidova, Naylya; Sail, Paul; Saitta, Biagio; Salustino Guimaraes, Valdir; Sanchez Mayordomo, Carlos; Sanmartin Sedes, Brais; Santacesaria, Roberta; Santamarina Rios, Cibran; Santovetti, Emanuele; Sarti, Alessio; Satriano, Celestina; Satta, Alessia; Saunders, Daniel Martin; Savrie, Mauro; Savrina, Darya; Schiller, Manuel; Schindler, Heinrich; Schlupp, Maximilian; Schmelling, Michael; Schmidt, Burkhard; Schneider, Olivier; Schopper, Andreas; Schune, Marie Helene; Schwemmer, Rainer; Sciascia, Barbara; Sciubba, Adalberto; Seco, Marcos; Semennikov, Alexander; Sepp, Indrek; Serra, Nicola; Serrano, Justine; Sestini, Lorenzo; Seyfert, Paul; Shapkin, Mikhail; Shapoval, Illya; Shcheglov, Yury; Shears, Tara; Shekhtman, Lev; Shevchenko, Vladimir; Shires, Alexander; Silva Coutinho, Rafael; Simi, Gabriele; Sirendi, Marek; Skidmore, Nicola; Skwarnicki, Tomasz; Smith, Anthony; Smith, Edmund; Smith, Eluned; Smith, Jackson; Smith, Mark; Snoek, Hella; Sokoloff, Michael; Soler, Paul; Soomro, Fatima; Souza, Daniel; Souza De Paula, Bruno; Spaan, Bernhard; Sparkes, Ailsa; Spradlin, Patrick; Sridharan, Srikanth; Stagni, Federico; Stahl, Marian; Stahl, Sascha; Steinkamp, Olaf; Stenyakin, Oleg; Stevenson, Scott; Stoica, Sabin; Stone, Sheldon; Storaci, Barbara; Stracka, Simone; Straticiuc, Mihai; Straumann, Ulrich; Stroili, Roberto; Subbiah, Vijay Kartik; Sun, Liang; Sutcliffe, William; Swientek, Krzysztof; Swientek, Stefan; Syropoulos, Vasileios; Szczekowski, Marek; Szczypka, Paul; Szilard, Daniela; Szumlak, Tomasz; T'Jampens, Stephane; Teklishyn, Maksym; Tellarini, Giulia; Teubert, Frederic; Thomas, Christopher; Thomas, Eric; van Tilburg, Jeroen; Tisserand, Vincent; Tobin, Mark; Tolk, Siim; Tomassetti, Luca; Topp-Joergensen, Stig; Torr, Nicholas; Tournefier, Edwige; Tourneur, Stephane; Tran, Minh Tâm; Tresch, Marco; Tsaregorodtsev, Andrei; Tsopelas, Panagiotis; Tuning, Niels; Ubeda Garcia, Mario; Ukleja, Artur; Ustyuzhanin, Andrey; Uwer, Ulrich; Vacca, Claudia; Vagnoni, Vincenzo; Valenti, Giovanni; Vallier, Alexis; Vazquez Gomez, Ricardo; Vazquez Regueiro, Pablo; Vázquez Sierra, Carlos; Vecchi, Stefania; Velthuis, Jaap; Veltri, Michele; Veneziano, Giovanni; Vesterinen, Mika; Viaud, Benoit; Vieira, Daniel; Vieites Diaz, Maria; Vilasis-Cardona, Xavier; Vollhardt, Achim; Volyanskyy, Dmytro; Voong, David; Vorobyev, Alexey; Vorobyev, Vitaly; Voß, Christian; Voss, Helge; de Vries, Jacco; Waldi, Roland; Wallace, Charlotte; Wallace, Ronan; Walsh, John; Wandernoth, Sebastian; Wang, Jianchun; Ward, David; Watson, Nigel; Websdale, David; Whitehead, Mark; Wicht, Jean; Wiedner, Dirk; Wilkinson, Guy; Williams, Matthew; Williams, Mike; Wilschut, Hans; Wilson, Fergus; Wimberley, Jack; Wishahi, Julian; Wislicki, Wojciech; Witek, Mariusz; Wormser, Guy; Wotton, Stephen; Wright, Simon; Wyllie, Kenneth; Xie, Yuehong; Xing, Zhou; Xu, Zhirui; Yang, Zhenwei; Yuan, Xuhao; Yushchenko, Oleg; Zangoli, Maria; Zavertyaev, Mikhail; Zhang, Liming; Zhang, Wen Chao; Zhang, Yanxi; Zhelezov, Alexey; Zhokhov, Anatoly; Zhong, Liang; Zvyagin, Alexander

    2015-02-04

    Using the latest LHCb measurements of time-dependent $C\\!P$ violation in the $B^0_s \\to K^+K^-$ decay, a U-spin relation between the decay amplitudes of $B^0_s \\to K^+K^-$ and $B^0\\to \\pi^+\\pi^-$ decay processes allows constraints to be placed on the angle $\\gamma$ of the unitarity triangle and on the $B^0_s$ mixing phase $-2\\beta_s$. Results from an extended approach, which uses additional inputs on $B^0\\to \\pi^0\\pi^0$ and $B^+\\to \\pi^+\\pi^0$ decays from other experiments and exploits isospin symmetry, are also presented. The dependence of the results on the maximum allowed amount of U-spin breaking is studied. At 68% probability, the value $\\gamma = \\left( 63.5^{\\,+\\, 7.2}_{\\,-\\,6.7} \\right)^\\circ~\\mathrm{modulo}~180^\\circ$ is determined. In an alternative analysis, the value $-2\\beta_s = -0.12 ^{\\,+\\,0.14}_{\\,-\\,0.16}\\,\\,\\mathrm{rad}$ is found. In both measurements, the uncertainties due to U-spin breaking effects up to 50% are included.

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

    International Nuclear Information System (INIS)

    Faessler, A.

    2006-01-01

    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 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

  12. Tables of double beta decay data

    International Nuclear Information System (INIS)

    Tretyak, V.I.

    1995-01-01

    A compilation of experimental data on double beta decay is presented. The tables contain the most stringent known experimental limits or positive results of 2β transitions of 69 natural nuclides to ground and excited states of daughter nuclei for different channels (2β - ; 2β + ; εβ + ; 2ε) and modes (0ν; 2ν; 0νM) of decay. (authors). 189 refs., 9 figs., 3 tabs

  13. Searches for massive neutrinos in nuclear beta decay

    International Nuclear Information System (INIS)

    Jaros, J.A.

    1992-10-01

    The status of searches for massive neutrinos in nuclear beta decay is reviewed. The claim by an ITEP group that the electron antineutrino mass > 17eV has been disputed by all the subsequent experiments. Current measurements of the tritium beta spectrum limit m bar νe < 10 eV. The status of the 17 keV neutrino is reviewed. The strong null results from INS Tokyo and Argonne, and deficiencies in the experiments which reported positive effects, make it unreasonable to ascribe the spectral distortions seen by Simpson, Hime, and others to a 17keV neutrino. Several new ideas on how to search for massive neutrinos in nuclear beta decay are discussed

  14. Double beta decays and related subjects for particle and nuclear physics

    International Nuclear Information System (INIS)

    Ejiri, Hiroyasu

    1991-01-01

    Present status and some perspectives in 1990's are briefly given on double beta decays and related subjects. Subjects discussed are as follows I) Double beta decays without neutrinos, which require lepton number non-conservations and finite neutrino mass. II) Double beta decays followed by two neutrinos. III) Double weak processes with strangeness change ΔS = 2, leading to the H particle with 6 quarks of ss uu dd. IV) Charge non-conservation and electron decays. These are very rare nuclear processes studied by Ultra RAre-process NUclear Spectroscopy (URANUS). It is shown that URANUS is an important detector frontier of non-accelerator nuclear physics in 1990's. (orig.)

  15. $\\beta$-asymmetry measurements in nuclear $\\beta$-decay as a probe for non-standard model physics

    CERN Multimedia

    Roccia, S

    2002-01-01

    We propose to perform a series of measurements of the $\\beta$-asymmetry parameter in the decay of selected nuclei, in order to investigate the presence of possible time reversal invariant tensor contributions to the weak interaction. The measurements have the potential to improve by a factor of about four on the present limits for such non-standard model contributions in nuclear $\\beta$-decay.

  16. $\\beta$-decay studies using total-absorption spectroscopy

    CERN Document Server

    Algora, A; García-Borge, M J; Cano-Ott, D; Collatz, R; Courtin, S; Dessagne, P; Fraile-Prieto, L M; Gadea, A; Gelletly, W; Hellström, M; Janas, Z; Jungclaus, A; Kirchner, R; Karny, M; Le Scornet, G; Miehé, C; Maréchal, F; Moroz, F; Nacher, E; Poirier, E; Roeckl, E; Rubio, B; Rykaczewski, K; Taín, J L; Tengblad, O; Wittmann, V

    2004-01-01

    $\\beta$-decay experiments are a primary source of information for nuclear-structure studies and at the same time complementary to in- beam investigations of nuclei far from stability. Although both types of experiment are mainly based on $\\gamma$-ray spectroscopy, they face different experimental problems. The so-called " Pandemonium effect " is a critical problem in $\\beta$-decay if we are to test theoretically calculated transition probabilities. In this contribution we will present a solution to this problem using total absorption spectroscopy methods. We will also present some examples of experiments carried out with the Total Absorption Spectrometer (TAS) at GSI and describe a new device LUCRECIA recently installed at CERN.

  17. Simulations of Bunch Merging in a Beta Beam Decay Ring

    CERN Document Server

    Heinrich, Daniel Christopher; Chance, Antoine

    2011-01-01

    To further study neutrino oscillation properties a Beta Beam facility has been proposed. Beta decaying ions with high kinetic energy are stored in a storage ring ("Decay Ring") with straight sections to create pure focused (anti) electron neutrino beams. However to reach high sensitivity to neutrino oscillation parameters in the experiment the bunched beam intensity and duty cycle in the DR have to be optimized. The first CERN-based scenario, using 6He and 18Ne as neutrino sources, has been studied using a bunch merging RF scheme. Two RF cavities at different frequencies are used to capture newly injected bunches and then merge them into the stored bunches. It was shown that this scheme could satisfy the requirements on intensity and duty cycle set by the experiment. This merging scheme has now been revised with new simulation software providing new results for 6He and 18Ne. Furthermore bunch merging has been studied for the second CERN-based scenario using 8Li and 8B.

  18. New information on the $\\beta$-decay of $^{11}$Li from Doppler broadened $\\gamma$-lines

    CERN Document Server

    Fynbo, H O U; Cederkäll, J; Courtin, S; Dessagne, P; Jonson, B; Le Scornet, G; Nilsson, T; Nyman, G H; Poirier, E; Riisager, K; Tengblad, O; Wilhelmsen, K

    2004-01-01

    The $\\gamma$-ray spectrum following $\\beta$-decay of $^{11}$Li has been remeasured at the ISOLDE facility at CERN. Two new transitions were observed through the use of large Ge-detectors. Most $\\gamma$-decays will follow P-delayed neutron emission. Information on the energy of the neutron is derived from analysis of the $\\gamma$-line-shape and used to construct a partial decay scheme for $^{11}$Li. Lifetime values for the 1$^{-}$ and 2$^{-}$ levels in $^{10}$Be are also derived. A new partial decay scheme is presented. (43 refs).

  19. Determination of the neutrino mass from the beta decay of gaseous molecular tritium

    International Nuclear Information System (INIS)

    Decman, D.J.; Stoeffl, W.

    1992-06-01

    We set an upper limit of 8 eV for the mass of the electron antineutrino from studying the beta decay of tritium. We use a gaseous molecular tritium source, a high resolution magnetic spectrometer and a low background counting system to minimize the systematic errors encountered in these measurements. Our calibration data with radioactive 83m Kr enables us to measure our system response function and a good deal of atomic physics data. In addition to our end point results we have made the first measurement of the tritium beta decay spectrum below 200 keV. We find an excess of very low energy electrons which arise from molecular processes of the 3 He-T + ion

  20. Microscopic beta and gamma data for decay-heat needs

    International Nuclear Information System (INIS)

    Dickens, J.K.

    1983-01-01

    Microscopic beta and gamma data for decay-heat needs are defined as absolute-intensity spectral distributions of beta and gamma rays following radioactive decay of radionuclides created by, or following, the fission process. Four well-known evaluated data files, namely the US ENDF/B-V, the UK UKFPDD-2, the French BDN (for fission products), and the Japanese JNDC Nuclear Data Library, are reviewed. Comments regarding the analyses of experimental data (particularly gamma-ray data) are given; the need for complete beta-ray spectral measurements is emphasized. Suggestions on goals for near-term future experimental measurements are presented. 34 references

  1. Status of evidence for neutrinoless double beta decay, and the future. Genius and genius-TF

    International Nuclear Information System (INIS)

    Klapdor-Kleingrothaus, H.V.

    2004-01-01

    The first evidence for neutrinoless double beta decay has been observed in the HEIDELBERG-MOSCOW experiment, which is the most sensitive double beta decay experiment since ten years. This is the first evidence for lepton number violation and proves that the neutrino is a Majorana particle. It further shows that neutrino masses are degenerate. In addition it puts several stringent constraints on other physics beyond the Standard Model. The result from the HEIDEL-BERG-MOSCOW experiment is consistent with recent results from CMB investigations, with high energy cosmic rays, with the result from the g-2 experiment and with recent theoretical work. It is indirectly supported by the analysis of other Ge double beta experiments. The new project GENIUS will cover a wide range of the parameter space of predictions of SUSY for neutralinos as cold dark matter. Further it has the potential to be a real-time detector for low-energy (pp and 7 Be) solar neutrinos. A GENIUS Test Facility has come into operation on May 5, 2003. This is the first time that this novel technique for extreme background reduction in search for rare decays is applied under the background conditions of an underground laboratory. (author)

  2. Nuclear beta decay far from stability and astrophysics

    International Nuclear Information System (INIS)

    Klapdor, H.V.

    1988-01-01

    Beta decay data of nuclei far from stability are one of the most important nuclear physics input for the understanding of the element systhesis in the universe and determination of the age of the universe from cosmochronometers and by the latter have implications also for cosmology. The present status of theoretical predictions of beta decay far from stability will be reviewed and the impact on the above astrophysical questions will be outlined. First results of second generation microscopic calculations of β F half lives, which are at present in progress, will be presented. (orig.)

  3. Constraining neutrinoless double beta decay

    International Nuclear Information System (INIS)

    Dorame, L.; Meloni, D.; Morisi, S.; Peinado, E.; Valle, J.W.F.

    2012-01-01

    A class of discrete flavor-symmetry-based models predicts constrained neutrino mass matrix schemes that lead to specific neutrino mass sum-rules (MSR). We show how these theories may constrain the absolute scale of neutrino mass, leading in most of the cases to a lower bound on the neutrinoless double beta decay effective amplitude.

  4. Beta Decay in the Field of an Electromagnetic Wave and Experiments on Measuring the Neutrino Mass

    International Nuclear Information System (INIS)

    Dorofeev, O.F.; Lobanov, A.E.

    2005-01-01

    Investigations of the effect of an electromagnetic wave field on the beta-decay process are used to analyze the tritium-decay experimental data on the neutrino mass. It is shown that the electromagnetic wave can distort the beta spectrum, shifting the end point to the higher energy region. This phenomenon is purely classical and it is associated with the electron acceleration in the radiation field. Since strong magnetic fields exist in setups for precise measurement of the neutrino mass, the indicated field can appear owing to the synchrotron radiation mechanism. The phenomenon under consideration can explain the experimentally observed anomalies in the spectrum of the decay electrons; in particular, the effect of the 'negative square of the neutrino mass'

  5. First design for the optics of the decay ring for the beta-beams

    International Nuclear Information System (INIS)

    Chance, A.; Payet, J.

    2006-03-01

    The aim of the beta-beams is to produce pure electronic neutrino and anti-neutrino highly energetic beams, coming from beta radioactive disintegration decay of the 18 Ne 10+ and 6 He 2+ , directed to experiment situated in the Frejus tunnel. The high ion intensities are stored in a ring, until the ions decay. The losses due to the decay of the radioactive ions are compensated with regular injections. These should be done in presence of the circulating beam. The new ions are injected at a different energy from the stored beam energy, the design of the ring must enable this type of injection and accept the injected and stored beams. In this note, we will focus on the study of the design of such a ring at the first and second orders. We have reached the constraint on the dispersion in the injection section: a horizontal dispersion superior to 10 m with β x = 20 m. We have put sextupoles in the arcs to correct the chromaticity. In the same time, we have compensated the third order resonances to have a large enough dynamic aperture. So the decay ring accepts injected and stored beams. In a top-down approach, the high stored intensities impose to take into account the space charge effects. However, due to the merging, the beam blows up after each injection in the longitudinal space charge, which imposes to include a momentum collimation section in the decay ring

  6. Observed double beta decay spectra from 82Se, 100Mo, and 150Nd

    International Nuclear Information System (INIS)

    Elliott, S.R.; Moe, M.K.; Nelson, M.A.; Vient, M.A.

    1993-01-01

    Two-electron events resembling double beta decay are being observed at energies beyond the die-off of the spectrum predicted for the two-neutrino mode. The anomaly appears in three isotopes having different half lives and Q-values. Tests are now underway to determine its origin. (orig.)

  7. Limits on Tensor Coupling from Neutron $\\beta$-Decay

    OpenAIRE

    Pattie Jr, Robert W.; Hickerson, Kevin P.; Young, Albert R.

    2013-01-01

    Limits on the tensor couplings generating a Fierz interference term, b, in mixed Gamow-Teller Fermi decays can be derived by combining data from measurements of angular correlation parameters in neutron decay, the neutron lifetime, and $G_{\\text{V}}=G_{\\text{F}} V_{ud}$ as extracted from measurements of the $\\mathcal{F}t$ values from the $0^{+} \\to 0^{+}$ superallowed decays dataset. These limits are derived by comparing the neutron $\\beta$-decay rate as predicted in the standard model with t...

  8. Neutrinoless double beta decay in Gerda

    Science.gov (United States)

    Grabmayr, Peter; Gerda Collaboration

    2015-10-01

    The Germanium Detector Array (Gerda) experiment searches for the neutrinoless double beta decay in 76Ge. This lepton number violating process is predicted by extensions of the standard model. Gerda follows a staged approach by increasing mass and lowering the background level from phase to phase. Gerda is setup at the Gran Sasso underground laboratory of INFN, Italy. An array of high-purity germanium detectors is lowered directly in liquid argon for shielding and cooling. Further background reduction is achieved by an instrumented water buffer. In Phase I an exposure of 21.6 kg yr was collected at a background level of 10-2 cts/(keV kg yr). The lower limit on the half-life of 76Ge > 2 . 1 .1025 yr (90% C.L.) has been published. Further analyses search for decay into excited states or the accompanied Majoron decay. Presently, Phase II is in preparation which intends to reach a background level of 10-3 cts/(keV kg yr) and to increase the exposure to 100 kg yr. About 20 kg of novel thick-window BEGe (Broad Energy Germanium) detectors will be added and the liquid argon will be instrumented. The status of Phase II preparation and results from the commissioning runs will be presented as well as some further results from Phase I.

  9. Neutrinoless double beta decay in type I+II seesaw models

    Energy Technology Data Exchange (ETDEWEB)

    Borah, Debasish [Department of Physics, Tezpur University,Tezpur-784028 (India); Dasgupta, Arnab [Institute of Physics, Sachivalaya Marg,Bhubaneshwar-751005 (India)

    2015-11-30

    We study neutrinoless double beta decay in left-right symmetric extension of the standard model with type I and type II seesaw origin of neutrino masses. Due to the enhanced gauge symmetry as well as extended scalar sector, there are several new physics sources of neutrinoless double beta decay in this model. Ignoring the left-right gauge boson mixing and heavy-light neutrino mixing, we first compute the contributions to neutrinoless double beta decay for type I and type II dominant seesaw separately and compare with the standard light neutrino contributions. We then repeat the exercise by considering the presence of both type I and type II seesaw, having non-negligible contributions to light neutrino masses and show the difference in results from individual seesaw cases. Assuming the new gauge bosons and scalars to be around a TeV, we constrain different parameters of the model including both heavy and light neutrino masses from the requirement of keeping the new physics contribution to neutrinoless double beta decay amplitude below the upper limit set by the GERDA experiment and also satisfying bounds from lepton flavor violation, cosmology and colliders.

  10. LUCIFER: Scintillating bolometers for the search of Neutrinoless Double Beta Decay

    Energy Technology Data Exchange (ETDEWEB)

    Vignati, M. [Sapienza Universita di Roma and INFN Sezione di Roma, Roma, I-00185 (Italy)

    2012-08-15

    The nature of neutrino mass is one of the frontier problems of particle physics. Neutrinoless Double Beta Decay (0{nu}DBD) is a powerful tool to measure the neutrino mass and to test possible extensions of the Standard Model. Bolometers are excellent detectors to search for this rare decay, thanks to their good energy resolution and to the low background conditions in which they can operate. The current challenge consists in the reduction of the background, represented by environmental {gamma}'s and {alpha}'s, in view of a zero background experiment. We present the LUCIFER R and D, funded by an European grant, in which the background can be reduced by an order of magnitude with respect to the present generation experiments. The technique is based on the simultaneous bolometric measurement of the heat and of the scintillation light produced by a particle, that allows to discriminate between {beta} and {alpha} particles. The {gamma} background is reduced by choosing 0{nu}DBD candidate isotopes with transition energy above the environmental {gamma}'s spectrum. The prospect of this R and D are discussed.

  11. Study of multi-neutron emission in the $\\beta$-decay of $^{11}$Li

    CERN Multimedia

    A new investigation of neutron emission in the $\\beta$-decay of $^{11}$Li is proposed. The principal goal of this study will be to directly measure, for the first time for any system, two $\\beta$-delayed neutrons in coincidence and determine the energy and angular correlations. This will be possible using liquid scintillator detectors, capable of distinguishing between neutrons and ambient $\\gamma$ and cosmic-rays, coupled to a new digital electronics and acquisition system. In parallel, a considerably more refined picture of the single-neutron emission will be obtained.

  12. Neutrinoless Double Beta Decay with CUORE-0: Physics Results and Detector Performance

    Science.gov (United States)

    Canonica, L.

    2016-08-01

    The CUORE-0 experiment searches for neutrinoless double beta decay in ^{130}Te. It consists of an array of 52 tellurium dioxide crystals, operated as bolometers at a temperature of 10 mK, with a total mass of about 39 kg of TeO_2. CUORE-0 has been built to test the performance of the upcoming CUORE experiment and represents the largest ^{130}Te bolometric setup currently in operation. This experiment has been running in the Gran Sasso National Laboratory, Italy, since March 2013. We report the results of a search for neutrinoless double beta decay in 9.8 kg years ^{130}Te exposure, which allowed us to set the most stringent limit to date on this half-life. The performance of the detector in terms of background rate and energy resolution are also reported.

  13. The use of cosmic-ray muons in the energy calibration of the Beta-decay Paul Trap silicon-detector array

    Energy Technology Data Exchange (ETDEWEB)

    Hirsh, T. Y.; Perez Galvan, A.; Burkey, M.; Aprahamian, A.; Buchinger, F.; Caldwell, S.; Clark, J. A.; Gallant, A.; Heckmaier, E.; Levand, A. F.; Savard, G.

    2018-04-01

    This article presents an approach to calibrate the energy response of double-sided silicon strip detectors (DSSDs) for low-energy nuclear-science experiments by utilizing cosmic-ray muons. For the 1-mm-thick detectors used with the Beta-decay Paul Trap, the minimum-ionizing peak from these muons provides a stable and time-independent in situ calibration point at around 300 keV, which supplements the calibration data obtained above 3 MeV from sources. The muon-data calibration is achieved by comparing experimental spectra with detailed Monte Carlo simulations performed using GEANT4 and CRY codes. This additional information constrains the calibration at lower energies, resulting in improvements in quality and accuracy.

  14. Radiopurity assessment of the energy readout for the NEXT double beta decay experiment

    Science.gov (United States)

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

    2017-08-01

    The "Neutrino Experiment with a Xenon Time-Projection Chamber" (NEXT) experiment intends to investigate the neutrinoless double beta decay of 136Xe, and therefore requires a severe suppression of potential backgrounds. An extensive material screening and selection process was undertaken to quantify the radioactivity of the materials used in the experiment. Separate energy and tracking readout planes using different sensors allow us to combine the measurement of the topological signature of the event for background discrimination with the energy resolution optimization. The design of radiopure readout planes, in direct contact with the gas detector medium, was especially challenging since the required components typically have activities too large for experiments demanding ultra-low background conditions. After studying the tracking plane, here the radiopurity control of the energy plane is presented, mainly based on gamma-ray spectroscopy using ultra-low background germanium detectors at the Laboratorio Subterr&aposaneo de Canfranc (Spain). All the available units of the selected model of photomultiplier have been screened together with most of the components for the bases, enclosures and windows. According to these results for the activity of the relevant radioisotopes, the selected components of the energy plane would give a contribution to the overall background level in the region of interest of at most 2.4×10-4 counts keV-1 kg-1 y-1, satisfying the sensitivity requirements of the NEXT experiment.

  15. Measurement of the energy dependent beta asymmetry in the decay of 8Li

    International Nuclear Information System (INIS)

    Bigelow, R.A.; Quin, P.A.; Freedman, S.J.; Napolitano, J.

    1985-01-01

    Progress is reported on a new measurement of the beta decay asymmetry in 8 Li. Polarized 8 Li is produced via the reaction 7 Li(d,p) 8 Li using vector polarized deuterons from a crossed beam polarized source. Plastic scintillation electron counters are used to measure asymmetry, tensor polarization correlation and to monitor beam current. Results are graphed and systematic error sources are discussed. 4 refs

  16. Scalar-mediated double beta decay and LHC

    International Nuclear Information System (INIS)

    Gonzalez, L.; Helo, J.C.; Hirsch, M.; Kovalenko, S.G.

    2016-01-01

    The decay rate of neutrinoless double beta (0νββ) decay could be dominated by Lepton Number Violating (LNV) short-range diagrams involving only heavy scalar intermediate particles, known as “topology-II” diagrams. Examples are diagrams with diquarks, leptoquarks or charged scalars. Here, we compare the LNV discovery potentials of the LHC and 0νββ-decay experiments, resorting to three example models, which cover the range of the optimistic-pessimistic cases for 0νββ decay. We use the LHC constraints from dijet as well as leptoquark searches and find that already with 20/fb the LHC will test interesting parts of the parameter space of these models, not excluded by the current limits on 0νββ-decay.

  17. Scalar-mediated double beta decay and LHC

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, L. [Universidad Técnica Federico Santa María, Centro-Científico-Tecnológico de Valparaíso,Casilla 110-V, Valparaíso (Chile); Helo, J.C. [Universidad Técnica Federico Santa María, Centro-Científico-Tecnológico de Valparaíso,Casilla 110-V, Valparaíso (Chile); Departamento de Física, Facultad de Ciencias, Universidad de La Serena,Avenida Cisternas 1200, La Serena (Chile); Hirsch, M. [AHEP Group, Instituto de Física Corpuscular - C.S.I.C./Universitat de València,Edificio de Institutos de Paterna, Apartado 22085, E-46071 València (Spain); Kovalenko, S.G. [Universidad Técnica Federico Santa María, Centro-Científico-Tecnológico de Valparaíso,Casilla 110-V, Valparaíso (Chile)

    2016-12-23

    The decay rate of neutrinoless double beta (0νββ) decay could be dominated by Lepton Number Violating (LNV) short-range diagrams involving only heavy scalar intermediate particles, known as “topology-II” diagrams. Examples are diagrams with diquarks, leptoquarks or charged scalars. Here, we compare the LNV discovery potentials of the LHC and 0νββ-decay experiments, resorting to three example models, which cover the range of the optimistic-pessimistic cases for 0νββ decay. We use the LHC constraints from dijet as well as leptoquark searches and find that already with 20/fb the LHC will test interesting parts of the parameter space of these models, not excluded by the current limits on 0νββ-decay.

  18. Nuclear beta decay and the weak interaction

    International Nuclear Information System (INIS)

    Kean, D.C.

    1975-11-01

    Short notes are presented on various aspects of nuclear beta decay and weak interactions including: super-allowed transitions, parity violation, interaction strengths, coupling constants, and the current-current formalism of weak interaction. (R.L.)

  19. Nuclear transparency and double beta decay of molybdenum 100

    International Nuclear Information System (INIS)

    Nicholson, H.W.

    1992-08-01

    Data taking is now complete on a double beta decay experiment which has been carried out with collaborators from the Lawrence Berkeley Laboratory, the University of New Mexico, and the Idaho National Engineering Laboratory, and work is continuing on a second collaborative experiment, AGS experiment 850 at the Brookhaven National Laboratory to study nuclear color transparency. In March, the experimental apparatus used to search for double beta decay in molybdenum 100 in the Consil silver mine in Osburn, Idaho was dismantled, and the data analysis is in its final stages. No evidence has been seen for the O + → O + mode of zero neutrino double beta decay collaborators with a 1σ lifetime limit of 3 x 10 22 years. This limit is 7.5 times greater than the limit we published previously in Physical Review Letters in 1989. Backgrounds have been simulated and fits are currently underway to a simulated O + → 2 + mode of zero neutrino double beta decay to improve on a very preliminary 1σ lifetime limit of 2.3 x 10 21 years presented at the April, 1992 meeting of the APS in Washington. A scintillating fiber detector with three Hamamatsu, H4140, 256 channel multianode phototubes has been built, instrumented, and tested in the May--July 1992 run in the EVA detector at Brookhaven Laboratory's AGS. Preliminary results from this detector have been disappointing. it is likely that the detector will have to be substantially redesigned before the 1993 AGS run

  20. Contribution of short-lived nuclides to decay heat

    International Nuclear Information System (INIS)

    Katakura, Jun-ichi

    1987-01-01

    Comments are made on the calculation of decay heat, centering on evaluation of average decay energy. It is difficult to obtain sufficiently useful decay diagrams of short lived nucleides. High-energy levels are often missing in inferior decay diagrams, leading to an overestimation of the intensity of beta-rays at low-energy levels. Such an overestimation or underestimation due to the inferiority of a decay diagram is referred to as pandemonium effect. The pandemonium effect can be assessed by means of the ratio of the measured energy of the highest level of the daughter nuclide to the Q β -value of the beta-decay. When a satisfactory decay diagram cannot be obtained, the average decay energy has to be estimated by theoretical calculation. The gross theory for beta-decay proposed by Yamada and Takahashi is employed for the calculation. To carry out the calculation according to this theory, it is required to determine the value for the parameter Q 00 , the lowest energy of the daughter nuclide that meets the selection rule for beta-decay. Currently, Q 00 to be used for this purpose is estimated from data on the energy of the lowest level found in a decay diagram, even if it is inferior. Some examples of calculation of decay heat using the average beta- or gamma-ray energy are shown and compared with measurements. (author)

  1. Gross theory of beta-decay and half-lives of short-lived nuclei

    International Nuclear Information System (INIS)

    Yamada, Masami; Kondo, Norikatsu.

    1976-01-01

    The gross theory of beta-decay has been developed, and this theory offers the means of calculating directly the function of beta-decay intensity, then half-lives, complex beta spectra and so on are estimated from it. This paper presents the more refined theory by introducing the shell effect. The shell effect is considered in the intensity function. The half-lives in the electron decay of In with spin of 9/2 + , the positron decay of Bi, Po, At and Rn, and the decay of odd-odd nuclei were estimated. The introduction of the shell effect shows better agreement between the theory and the experimental data. The inequality relations of intensity functions and half-lives of two adjacent nuclei were obtained. When the spins and parities of two nuclei are same, the inequality relations hold especially good. (Kato, T.)

  2. Absolute measurement of the $\\beta\\alpha$ decay of $^{16}$N

    CERN Multimedia

    We propose to study the $\\beta$-decay of $^{16}$N at ISOLDE with the aim of determining the branching ratio for $\\beta\\alpha$ decay on an absolute scale. There are indications that the previously measured branching ratio is in error by an amount significantly larger than the quoted uncertainty. This limits the precision with which the S-factor of the astrophysically important $^{12}$C($\\alpha, \\gamma)^{16}$O reaction can be determined.

  3. The SNO+ experiment for neutrinoless double-beta decay

    Energy Technology Data Exchange (ETDEWEB)

    Lozza, Valentina; Krosigk, Belina von; Soerensen, Arnd; Zuber, Kai [Institut fuer Kern- und Teilchenphysik, Dresden (Germany)

    2015-07-01

    SNO+ is a large liquid scintillator based experiment that re-uses the Sudbury Neutrino Observatory detector. The detector, located 2 km underground in a mine near Sudbury, Canada, consists of a 12 m diameter acrylic vessel which will be filled with 780 tonnes of liquid scintillator. The main physics goal of SNO+ is to search for the neutrinoless double-beta (0n2b) decay of {sup 130}Te. During the double-beta phase, the liquid scintillator will be initially loaded with 0.3% natural tellurium (nearly 800 kg of {sup 130}Te). During this demonstration phase we anticipate that we will achieve a sensitivity in the region just above the inverted neutrino mass hierarchy. Recently the possibility to deploy up to 10 times more natural tellurium is being developed, by which SNO+ could explore, in the near future, deep into the parameter space for the inverted hierarchy. Designed as a general purpose neutrino experiment, SNO+ can additionally measure the reactor neutrino oscillations, geo-neutrinos in a geologically-interesting location, watch supernova neutrinos and measure low energy solar neutrinos. A first commissioning phase with the detector filled with water has started in autumn 2014, while full running with water will take place in 2015. Transition to the scintillator phase will start towards the end of 2015. The 0n2b decay phase is foreseen for the 2016.

  4. Measurement of beta decay energies of short-lived neutron rich atomic nuclei in the mass range 101 ≤ A ≤ 106 and A=109

    International Nuclear Information System (INIS)

    Weikard, H.

    1986-01-01

    At the mass separator LOHENGRIN of the Laue-Langevin institute in Grenoble for 18 nuclei (Zr, Nb, Mo, Tc, Ru, and Rh nuclides) with masses 101 ≤ A ≤ 106 and A=109 Q β values were determined from measurement of beta decay energies. From the study of the isomerism in 102 Nb resulted that the energetic distance of the two isomers is certainly smaller than 200 keV, that it is probably even smaller than 100 keV. The decay scheme for 102 Nb could be extended by one level which is depopulated by two gamma lines. For the decay of the 109 Ru the approach of a decay scheme is given: Five new levels are proposed. The diagrams of the two-particle separation energies which could be extended in this thesis confirm the continuation of the deformation in the considered region. A deformed subshell at N=62 however cannot yet be clearly detected. (orig./HSI) [de

  5. Double beta decays studied by β-γ spectroscopy with a drift chamber

    International Nuclear Information System (INIS)

    Okada, K.; Ejiri, H.; Shibata, T.

    1986-01-01

    A large scale ultra low background β-γ spectrometer ELEGANTS-V for studying double beta decays(ββ) of /sup 100/Mo and/or /sup 150/Nd is designed and is now under construction. It consists of drift chambers for identification of tracks and vertex of two β-rays, thin NaI(T1) or plastic scintillators for β-rays energy and NaI(T1) counters for γ- and cosmic-rays. Specifications of the spectrometer; energy resolution, detection efficiency, possible background counting rate and available ββ sources, have been evaluated. The spectrometer has extremely high sensitivities of the neutrinoless ββ decays (0νββ), two neutrino ββ decays (2νββ) and neutrinoless ββ decays followed one boson (Majoron). It may detect 0νββ decays with half lives up to T/sub 1/2/ = 1.2- 1.7 . 10/sup 23/ year. This limit corresponds to one part of million for the Majoran neutrino mass in units of the electron mass and for the right-handed weak current in units of the left handed one

  6. Status of double beta decay experiments using isotopes other than 136Xe

    Science.gov (United States)

    Pandola, L.

    2014-09-01

    Neutrinoless double beta decay is a lepton-number violating process predicted by many extensions of the standard model. It is actively searched for in several candidate isotopes within many experimental projects. The status of the experimental initiatives which are looking for the neutrinoless double beta decay in isotopes other than 136Xe is reviewed, with special emphasis given to the projects that passed the R&D phase. The results recently released by the experiment GERDA are also summarized and discussed. The GERDA data give no positive indication of neutrinoless double beta decay of 76Ge and disfavor in a model-independent way the long-standing observation claim on the same isotope. The lower limit reported by GERDA for the half-life of neutrinoless double beta decay of 76Ge is T1/20ν > 2.1 ṡ1025 yr (90% C.L.), or T1/20ν > 3.0 ṡ1025 yr, when combined with the results of other 76Ge predecessor experiments.

  7. Study of the deuteron emission in the $\\beta$-decay of $^{6}$He

    CERN Multimedia

    Karny, M; Tengblad, O; Riisager, K; Perkowski, J; Garcia borge, M J; Raabe, R; Kowalska, M; Fynbo, H O U; Perea martinez, A; Ter-akopian, G; Huyse, M L

    The main goal of the present proposal is to measure the continuous spectrum of deuterons emitted in the $\\beta$-decay of $^{6}$He. In particular, we want to focus on the low energy part of the spectrum, below 400 keV, which could not be accessed by all previous experiments. For the decay spectroscopy the Warsaw Optical Time Projection Chamber (OTPC) will be used. The bunches of $^{6}$He ions produced by REX-ISOLDE facility will be implanted into the active volume of the OTPC, where the rare events of deuteron emission will be recorded, practically background free.

  8. Extra dimensions and neutrinoless double beta decay experiments

    International Nuclear Information System (INIS)

    Gozdz, Marek; Kaminski, Wieslaw A.; Faessler, Amand

    2005-01-01

    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

  9. Signal and background studies for the search of neutrinoless double beta decay in GERDA

    Energy Technology Data Exchange (ETDEWEB)

    Agostini, Matteo

    2013-04-24

    The GERDA experiment searches for the neutrinoless double beta decay in Ge-76, by operating bare HPGe detectors in ultra-pure liquid Ar. This dissertation presents a first decomposition of the background measured in the current data-taking phase. The background at the energy of interest was found to be dominated by {sup 214}Bi, {sup 208}Tl and {sup 42}K gamma-rays, with secondary contributions from {sup 42}K and {sup 214}Bi beta-rays, and {sup 210}Po alpha-rays. For the forthcoming upgrade of the apparatus, a new HPGe detector design (BEGe) has been studied, with focus on its capability of suppressing the identified backgrounds through pulse shape analysis. This included the development of a comprehensive modeling of the detectors and the experimental characterization of their response to surface interactions. The achieved results show that GERDA can improve the present limit on the neutrinoless double beta decay half-life by an order of magnitude.

  10. Signal and background studies for the search of neutrinoless double beta decay in GERDA

    International Nuclear Information System (INIS)

    Agostini, Matteo

    2013-01-01

    The GERDA experiment searches for the neutrinoless double beta decay in Ge-76, by operating bare HPGe detectors in ultra-pure liquid Ar. This dissertation presents a first decomposition of the background measured in the current data-taking phase. The background at the energy of interest was found to be dominated by 214 Bi, 208 Tl and 42 K gamma-rays, with secondary contributions from 42 K and 214 Bi beta-rays, and 210 Po alpha-rays. For the forthcoming upgrade of the apparatus, a new HPGe detector design (BEGe) has been studied, with focus on its capability of suppressing the identified backgrounds through pulse shape analysis. This included the development of a comprehensive modeling of the detectors and the experimental characterization of their response to surface interactions. The achieved results show that GERDA can improve the present limit on the neutrinoless double beta decay half-life by an order of magnitude.

  11. Large-scale calculations of the beta-decay rates and r-process nucleosynthesis

    Energy Technology Data Exchange (ETDEWEB)

    Borzov, I N; Goriely, S [Inst. d` Astronomie et d` Astrophysique, Univ. Libre de Bruxelles, Campus Plaine, Bruxelles (Belgium); Pearson, J M [Inst. d` Astronomie et d` Astrophysique, Univ. Libre de Bruxelles, Campus Plaine, Bruxelles (Belgium); [Lab. de Physique Nucleaire, Univ. de Montreal, Montreal (Canada)

    1998-06-01

    An approximation to a self-consistent model of the ground state and {beta}-decay properties of neutron-rich nuclei is outlined. The structure of the {beta}-strength functions in stable and short-lived nuclei is discussed. The results of large-scale calculations of the {beta}-decay rates for spherical and slightly deformed nuclides of relevance to the r-process are analysed and compared with the results of existing global calculations and recent experimental data. (orig.)

  12. Challenges in Double Beta Decay

    Directory of Open Access Journals (Sweden)

    Oliviero Cremonesi

    2014-01-01

    Full Text Available In the past ten years, neutrino oscillation experiments have provided the incontrovertible evidence that neutrinos mix and have finite masses. These results represent the strongest demonstration that the electroweak Standard Model is incomplete and that new Physics beyond it must exist. In this scenario, a unique role is played by the Neutrinoless Double Beta Decay searches which can probe lepton number conservation and investigate the Dirac/Majorana nature of the neutrinos and their absolute mass scale (hierarchy problem with unprecedented sensitivity. Today Neutrinoless Double Beta Decay faces a new era where large-scale experiments with a sensitivity approaching the so-called degenerate-hierarchy region are nearly ready to start and where the challenge for the next future is the construction of detectors characterized by a tonne-scale size and an incredibly low background. A number of new proposed projects took up this challenge. These are based either on large expansions of the present experiments or on new ideas to improve the technical performance and/or reduce the background contributions. In this paper, a review of the most relevant ongoing experiments is given. The most relevant parameters contributing to the experimental sensitivity are discussed and a critical comparison of the future projects is proposed.

  13. The Standard Model and the neutron beta-decay

    CERN Document Server

    Abele, H

    2000-01-01

    This article reviews the relationship between the observables in neutron beta-decay and the accepted modern theory of particle physics known as the Standard Model. Recent neutron-decay measurements of various mixed American-British-French-German-Russian collaborations try to shed light on the following topics: the coupling strength of charged weak currents, the universality of the electroweak interaction and the origin of parity violation.

  14. Electron acceleration during the decay of nonlinear Whistler waves in low-beta electron-ion plasma

    International Nuclear Information System (INIS)

    Umeda, Takayuki; Saito, Shinji; Nariyuki, Yasuhiro

    2014-01-01

    Relativistic electron acceleration through dissipation of a nonlinear, short-wavelength, and monochromatic electromagnetic whistler wave in low-beta plasma is investigated by utilizing a one-dimensional fully relativistic electromagnetic particle-in-cell code. The nonlinear (large-amplitude) parent whistler wave decays through the parametric instability which enhances electrostatic ion acoustic waves and electromagnetic whistler waves. These waves satisfy the condition of three-wave coupling. Through the decay instability, the energy of electron bulk velocity supporting the parent wave is converted to the thermal energy perpendicular to the background magnetic field. Increase of the perpendicular temperature triggers the electron temperature anisotropy instability which generates broadband whistler waves and heats electrons in the parallel direction. The broadband whistler waves are inverse-cascaded during the relaxation of the electron temperature anisotropy. In lower-beta conditions, electrons with a pitch angle of about 90° are successively accelerated by inverse-cascaded whistler waves, and selected electrons are accelerated to over a Lorentz factor of 10. The result implies that the nonlinear dissipation of a finite-amplitude and short-wavelength whistler wave plays an important role in producing relativistic nonthermal electrons over a few MeV especially at lower beta plasmas.

  15. Q values of the 76Ge and 100Mo double-beta decays

    International Nuclear Information System (INIS)

    Rahaman, S.; Elomaa, V.-V.; Eronen, T.; Hakala, J.; Jokinen, A.; Julin, J.; Kankainen, A.; Saastamoinen, A.; Suhonen, J.; Weber, C.; Aystoe, J.

    2008-01-01

    Penning trap measurements using mixed beams of 76 Ge- 76 Se and 100 Mo- 100 Ru have been utilized to determine the double-beta decay Q-values of 76 Ge and 100 Mo with uncertainties less than 200 eV. The value for 76 Ge, 2039.04(16) keV is in agreement with the published SMILETRAP value, 2039.006(50) keV. The new value for 100 Mo, 3034.40(17) keV is 30 times more precise than the previous literature value, sufficient for the ongoing neutrinoless double-beta decay searches in 100 Mo. Moreover, the precise Q-value is used to calculate the phase-space integrals and the experimental nuclear matrix element of double-beta decay

  16. Precision Study of the $\\beta$-decay of $^{62}$Ga

    CERN Multimedia

    2002-01-01

    It is proposed to perform a precision study of the $\\beta$-decay of $\\,^{62}$Ga taking advantage of recent developments of the ISOLDE Laser Ion Source. The goal is to eventually extend the high-precision knowledge of superallowed $\\beta$-decays beyond the nine decays that presently are used for extracting the V$_{ud}$ quark mixing matrix element of the CKM matrix. The scientific motivations are the current deviation of more than 2$\\sigma$ of the unitary condition of this matrix, which could be an indication of non-standard-model physics, and a test of the theoretical corrections applied to the experimental data. The experiment will utilise the Total Absorption $\\gamma$-ray (TAG) spectrometer in order to determine weak branchings to excited states in $^{62}$Zn and the ISOLDE spectroscopy station to perform half-life measurements and detailed spectroscopy of this nucleus.

  17. Weak interaction studies from nuclear beta decay

    International Nuclear Information System (INIS)

    Morita, M.

    1981-01-01

    The studies performed at the theoretical nuclear physics division of the Laboratory of Nuclear Studies, Osaka University, are reported. Electron spin density and internal conversion process, nuclear excitation by electron transition, beta decay, weak charged current, and beta-ray angular distributions in oriented nuclei have been studied. The relative intensity of internal conversion electrons for the case in which the radial wave functions of orbital electrons are different for electron spin up and down was calculated. The calculated value was in good agreement with the experimental one. The nuclear excitation following the transition of orbital electrons was studied. The calculated probability of the nuclear excitation of Os 189 was 1.4 x 10 - 7 in conformity with the experimental value 1.7 x 10 - 7 . The second class current and other problems on beta-decay have been extensively studied, and described elsewhere. Concerning weak charged current, the effects of all induced terms, the time component of main axial vector, all partial waves of leptons, Coulomb correction for the electrons in finite size nuclei, and radiative correction were studied. The beta-ray angular distribution for the 1 + -- 0 + transition in oriented B 12 and N 12 was investigated. In this connection, investigation on the weak magnetism to include all higher order corrections for the evaluation of the spectral shape factors was performed. Other works carried out by the author and his collaborators are also explained. (Kato, T.)

  18. Beta-decay studies at the N=28 shell closure

    Czech Academy of Sciences Publication Activity Database

    Grévy, S.; Mrázek, Jaromír; Angelique, J. C.; Baumann, P.; Borcea, C.; Buta, A.; Canchel, G.; Cargord, W.; Courtin, S.; Daugas, J. M.; de Oliveira Santos, F.; Dlouhý, Zdeněk; Knipper, A.; Kratz, K. L.; Lecouey, J. L.; Lecolley, F. R.; Lehrsenneau, G.; Lewitowicz, M.; Lienard, E.; Lukianov, S.; Marechal, F.; Miehe, C.; Negoita, F.; Orr, NA.; Pantelica, D.; Penionzhkevich, Y. E.; Peter, J.; Pfeiffer, B.; Pietri, S.; Poirier, E.; Sorlin, O.; Stanoiu, M.; Stodel, C.; Timis, C.

    2003-01-01

    Roč. 722, - (2003), s. 424C-428C ISSN 0375-9474 R&D Projects: GA AV ČR IAA1048605; GA AV ČR KSK1048102 Institutional research plan: CEZ:AV0Z1048901 Keywords : beta-decay spectroscopy * beta half-lives Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 1.761, year: 2003

  19. $\\beta$ - decay asymmetry in mirror nuclei: A = 9

    CERN Multimedia

    Axelsson, L E; Smedberg, M

    2002-01-01

    Investigations of light nuclei close to the drip lines have revealed new and intriguing features of the nuclear structure. The occurrence of halo structures in loosely bound systems has had a great impact on the nuclear physics research in the last years. As intriguing but not yet solved is the nature of transitions with very large $\\beta$ - strength. \\\\ \\\\We report here on the investigation of this latter feature by an accurate measurement of the $\\beta$ - decay asymmetry between the mirror nuclei in the A=9 mass chain.\\\\ \\\\The possible asymmetry for the decay to the states around 12 MeV is interesting not only due to the fact that the individual B$_{GT}$ values are large (with large overlap in wave-functions, an unambiguous interpretation is much easier made), but also due to the special role played by this transition for the $^{9}$Li decay. It seems to belong to a class of high-B$_{GT}$ transitions observed at the neutron drip line and has been suggested to be due either to a lowering of the giant Gamow-Te...

  20. Beta decay of 31,32Na and 31Mg

    International Nuclear Information System (INIS)

    Klotz, G.; Baumann, P.; Bounajma, M.; Huck, A.; Knipper, A.; Walter, G.; Poves, A.; Retamosa, J.

    1993-01-01

    31,32 Na and 31 Mg beta decays were studied at the CERN on-line mass separator ISOLDE by gamma, gamma-gamma and neutron-gamma measurements. In the 31 Na decay, the assignment of previously reported γ transitions and the observation of a new level at 3760 keV lead to a revised decay scheme. In the 31 Mg → 31 Al decay, a new decay scheme involves ten β branches and three states are reported for the first time. New spectroscopic results have been obtained in the 32 Na β - decay. A previously non-interpreted 1436 keV γ ray is now assigned in the 32 Mg scheme. (author) 33 refs., 16 figs., 12 tabs

  1. Beta decay rates of neutron-rich nuclei

    International Nuclear Information System (INIS)

    Marketin, Tomislav; Huther, Lutz; Martínez-Pinedo, Gabriel

    2015-01-01

    Heavy element nucleosynthesis models involve various properties of thousands of nuclei in order to simulate the intricate details of the process. By necessity, as most of these nuclei cannot be studied in a controlled environment, these models must rely on the nuclear structure models for input. Of all the properties, the beta-decay half-lives are one of the most important ones due to their direct impact on the resulting abundance distributions. Currently, a single large-scale calculation is available based on a QRPA calculation with a schematic interaction on top of the Finite Range Droplet Model. In this study we present the results of a large-scale calculation based on the relativistic nuclear energy density functional, where both the allowed and the first-forbidden transitions are studied in more than 5000 neutron-rich nuclei

  2. Beta decay rates of neutron-rich nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Marketin, Tomislav, E-mail: marketin@phy.hr [Department of Physics, Faculty of Science, University of Zagreb, 10000 Zagreb (Croatia); Huther, Lutz [Institut für Kernphysik (Theoriezentrum), Technische Universität Darmstadt, 64289 Darmstadt (Germany); Martínez-Pinedo, Gabriel [Institut für Kernphysik (Theoriezentrum), Technische Universität Darmstadt, 64289 Darmstadt (Germany); GSI Helmholtzzentrum für Schwerioneneforschung, Planckstraße 1, 64291 Darmstadt (Germany)

    2015-10-15

    Heavy element nucleosynthesis models involve various properties of thousands of nuclei in order to simulate the intricate details of the process. By necessity, as most of these nuclei cannot be studied in a controlled environment, these models must rely on the nuclear structure models for input. Of all the properties, the beta-decay half-lives are one of the most important ones due to their direct impact on the resulting abundance distributions. Currently, a single large-scale calculation is available based on a QRPA calculation with a schematic interaction on top of the Finite Range Droplet Model. In this study we present the results of a large-scale calculation based on the relativistic nuclear energy density functional, where both the allowed and the first-forbidden transitions are studied in more than 5000 neutron-rich nuclei.

  3. Program BETA for simulation of particle decays and reactions

    International Nuclear Information System (INIS)

    Takhtamyshev, G.G.; Merkulova, T.A.

    1997-01-01

    Program BETA is designed for simulation of particle decays and reactions. The program also produces integration over the phase space and decay rate or the reaction cross section are calculated as a result of such integration. At the simulation process the adaptive random number generator SMART may be used, what is found to be useful for some difficult cases

  4. The GERDA Neutrinoless Double Beta-Decay Experiment

    International Nuclear Information System (INIS)

    Majorovits, Bela A.

    2007-01-01

    Neutrinoless double beta (0νββ)-decay is the key process to gain understanding of the nature of neutrinos. The GErmanium Detector Array (GERDA) is designed to search for 0νββ-decay of the isotope 76 Ge. Germanium crystals enriched in 76 Ge, acting as source and detector simultaneously, will be submerged directly into an ultra pure cooling medium that also serves as a radiation shield. This concept will allow for a reduction of the background by up to two orders of magnitudes with respect to earlier experiments

  5. The next enriched xenon observatory. A search for neutrinoless double beta decay

    Energy Technology Data Exchange (ETDEWEB)

    Bayerlein, Reimund; Hufschmidt, Patrick; Jamil, Ako; Schneider, Judith; Wagenpfeil, Michael; Wrede, Gerrit; Ziegler, Tobias; Hoessl, Juergen; Anton, Gisela; Michel, Thilo [ECAP, Friedrich-Alexander-Universitaet Erlangen-Nuernberg (Germany)

    2016-07-01

    The question whether the neutrino could be its own antiparticle is still not answered. The most practical way to test this is the search for the neutrinoless double beta decay. The half-life of this decay is related to the value of a linear combination of the masses of the neutrino mass eigenstates and therefore provides information about the absolute mass scale of neutrinos. The nEXO experiment - the successor of EXO200 - is currently under research and development. The baseline concept comprises a single-phase liquid xenon (LXe) time projection chamber (TPC) filled with about 5 tons of liquid xenon enriched to about 80% Xe-136 as the double beta decay nuclide. In order to fully cover the range of the effective Majorana neutrino mass in the inverted hierarchy scheme, excellent energy resolution is required. Therefore, a position-resolving, low-noise charge readout and very efficient light collection and detection are mandatory. For the purpose of very low background levels radiopure Silicon Photomultipliers (SiPMs) have to be used to detect the scintillation light of LXe. Due to the large half-life a huge detector mass and long term measurement are needed. In this talk the baseline-concept of the experimental setup is presented.

  6. Double Beta Decay Experiments: Present Status and Prospects for the Future

    Science.gov (United States)

    Barabash, A. S.

    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 T1/2(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 ( at the level of ˜ (0.01-0.1) eV are discussed. The main attention is paid to experiments of CUORE, GERDA, MAJORANA, EXO, KamLAND-Zen-2, SuperNEMO and SNO+. Possibilities of low-temperature scintillating bolometers on the basis of inorganic crystals (ZnSe, ZnMoO4, Li2MoO4, CaMoO4 and CdWO4) are considered too.

  7. Double Beta Decay and Neutrino Masses Accuracy of the Nuclear Matrix Elements

    International Nuclear Information System (INIS)

    Faessler, Amand

    2005-01-01

    The neutrinoless double beta decay is forbidden in the standard model of the electroweak and strong interaction but allowed in most Grand Unified Theories (GUT's). Only if the neutrino is a Majorana particle (identical with its antiparticle) and if it has a mass, the neutrinoless double beta decay is allowed. Apart of one claim that the neutrinoless double beta decay in 76 Ge is measured, one has only upper limits for this transition probability. But even the upper limits allow to give upper limits for the electron Majorana neutrino mass and upper limits for parameters of GUT's 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 GUT's. For that one has to assume that the specific mechanism is the leading one for the neutrinoless double beta decay and one has to be able to calculate reliably the corresponding nuclear matrix elements. In the present contribution, one discusses the accuracy of the present status of calculating the nuclear matrix elements and the corresponding limits of GUT's and supersymmetric parameters

  8. First results of neutrinoless double beta decay search with the GERmanium Detector Array "GERDA"

    Science.gov (United States)

    Janicskó Csáthy, József

    2014-06-01

    The study of neutrinoless double beta decay is the most powerful approach to the fundamental question if the neutrino is a Majorana particle, i.e. its own anti-particle. The observation of the lepton number violating neutrinoless double beta decay would establish the Majorana nature of the neutrino. Until now neutrinoless double beta decay was not observed. The GERmanium Detector Array, GERDA is a double beta decay experiment located at the INFN Gran Sasso National Laboratory, Italy. GERDA operates bare Ge diodes enriched in 76Ge in liquid argon supplemented by a water shield. The exposure accumulated adds up to 21.6 kg· yr with a background level of 1.8 · 10-2 cts/(keV·kg·yr). The results of the Phase I of the experiment are presented and the preparation of the Phase II is briefly discussed.

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

    Science.gov (United States)

    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.

  10. On the importance of low-energy beta-beams for supernova neutrino physics

    International Nuclear Information System (INIS)

    Jachowicz, N.; McLaughlin, G.C.

    2005-01-01

    Beta beams, which are neutrino beams produced by the beta decay of nuclei that have been accelerated to high gamma factor, were original proposed for high energy applications, such as the measurement of the third neutrino mixing angle θ 13 . Volpe suggested that a beta beam run at lower gamma factor, would be useful for neutrino measurements in the tens of MeV range. We suggest to exploit the flexibility these beta beam facilities offer, combined with the fact that beta-beam neutrino energies overlap with supernova-neutrino energies, to construct 'synthetic' spectra that approximate an incoming supernova-neutrino energy-distribution. Using these constructed spectra we are able to reproduce total and differential folded supernova-neutrino cross-sections very accurately. We illustrate this technique using Deuterium, 16 O, and 208 Pb. This technique provides an easy and straightforward way to apply the results of a beta-beam neutrino-nucleus measurement to the corresponding supernova-neutrino detector, virtually eliminating potential uncertainties due to nuclear-structure calculations. (author)

  11. The Majorana project: sup 7 sup 6 Ge 0 nu beta beta-decay neutrino mass measurement

    CERN Document Server

    Aalseth, C E

    2002-01-01

    Interest in, and the relevance of, next-generation 0 nu beta beta-decay experiments is increasing. Even with nonzero neutrino mass strongly suggested by SNO, Super Kamiokande, and similar experiments sensitive to delta m sup 2 , 0 nu beta beta-decay experiments are still the only way to establish the Dirac or Majorana nature of neutrinos by measuring effective electron neutrino mass, . Various theorists have recently argued in favor of a neutrino mass between 0.01 and 1 eV. The Majorana Project aims to probe this effective neutrino mass range, reaching a sensitivity of 0.02-0.07 eV. The experiment relies entirely on proven technology and has been devised based upon the materials, technology, and data analysis demonstrated to produce the lowest background per kilogram of fiducial germanium. The project plan includes 500 kg of germanium detector material enriched to 85% in sup 7 sup 6 Ge, specialized pulse-acquisition electronics and detector segmentation for background rejection, and underground electroformed ...

  12. GERDA and the search for neutrinoless double beta decay: first results and perspectives

    Energy Technology Data Exchange (ETDEWEB)

    Agostini, Matteo [Physik Department and Excellence Cluster Universe, Technische Universitaet Muenchen (Germany); Collaboration: GERDA-Collaboration

    2014-07-01

    Neutrinoless double beta decay is a lepton-number-violating nuclear transition predicted by several extensions of the Standard Model. The Gerda experiment searches for this transition in {sup 76}Ge by operating bare Ge detectors in liquid Ar. The talk focuses on the results of data acquired during Phase I of the experiment, in which 21.6 kg.yr of exposure were accumulated with a background index of about 0.01 cts/(keV.kg.yr). No signal was observed and a lower limit was derived for the half-life of neutrinoless double beta decay of {sup 76}Ge, T{sub 1/2} > 2.1 . 10{sup 25} yr (90% C.L.). The experiment is currently undergoing a major upgrade in preparation for the next phase of data taking. Thanks to an increased target mass, an improved energy resolution and the introduction of novel background reduction techniques, the sensitivity of Gerda will increase of about one order of magnitude in a few years of operation.

  13. The double beta decay spectra of 82Se, 100Mo, and 150Nd

    International Nuclear Information System (INIS)

    Nelson, M.A.; Moe, M.K.; Vient, M.A.; Elliott, S.R.

    1992-01-01

    The double beta decay electron energy spectra of 82 Se, 100 Mo, and 150 Nd have been measured with a time projection chamber, and departures from the expected two-neutrino spectral shapes have been observed. Efforts to reduce possible background contamination have been made, and tests are now being done in an effort to determine whether the anomalous signals are real effects, or simply experimental artifacts

  14. An assessment of anti-neutrino mass determination via electrostatic measurements of tritium beta-decay

    International Nuclear Information System (INIS)

    Le Bas, P.A.

    1984-01-01

    Data on the mass of the anti-neutrino determined via electrostatic measurements of tritium beta-decay are assessed. Relativistic calculations concerning the finite mass of the electron anti-neutrino and the recoil of the nucleus, are given for the theoretical end-point spectrum of tritium beta-decay. The specifications are given for an electrostatic Spherical Retarding Beta-Spectrometer, and an electrostatic Cylindrical Mirror Analyser, both used in the tritium beta-decay experiment. The electrostatic measurements lead to a value of less than 50 ev (90% C.L.) for the electron anti-neutrino mass. These results are discussed in terms of the resolution of the electrostatic equipment and the Monte Carlo simulations of the data collection. (UK)

  15. Experimental proof of quantum non-separability based on the transition of the atom in beta-decay

    International Nuclear Information System (INIS)

    Vatai, E.

    1988-01-01

    The basic non-local character of the quantum processes is a continuously discussed and doubted problem of quantum theory. Recent experimental proofs of the Bell inequalities are questioned in the literature, using local theories of hidden variables. Present paper shows a simple and direct proof of non-locality of quantum processes, analyzing the case of the beta decay. The hypothetical energy transfer between shell electrons and beta electron-neutrino system is proved to be superluminal but necessary for the energy balance of the process. This argumentation proves the nonseparability and nonlocality of quantum processes. (D.G.) 8 refs

  16. Future of double beta decay and dark matter searches - GENIUS

    International Nuclear Information System (INIS)

    Klapdor-Kleingrothaus, H. V.; Baudis, L.; Heusser, G.; Krivosheina, I. V.; Kolb, S.; Majorovits, B.; Nabi, J.-U.; Paes, H.

    1999-01-01

    The recent results from the HEIDELBERG-MOSCOW experiment have demonstrated the large potential of double beta decay to search for new physics beyond the standard model. To increase further by a major step the present sensitivity for double beta decay and dark matter searches, we describe here a project, proposed recently [1], which would operate one tonne of 'naked' enriched germanium-detectors in liquid nitrogen as shielding in an underground set-up (GENIUS). It improves the sensitivity of neutrino masses to 0.01 eV. A 10 tonne version would probe neutrino masses even down to 10 -3 eV

  17. $\\beta$-decay studies using total absorption techniques some recent results

    CERN Document Server

    Algora, A; García-Borge, M J; Cano-Ott, D; Collatz, R; Courtin, S; Dessagne, P; Fraile-Prieto, L M; Gadea, A; Gelletly, W; Hellström, M; Janas, Z; Jungclaus, A; Karny, M; Kirchner, R; Maréchal, F; Miehé, C; Moroz, F; Nacher, E; Poirier, E; Roeckl, E; Rubio, B; Rykaczewski, K; Scornet, G L; Taín, J L; Tengblad, O; Wittmann, V

    2004-01-01

    $\\beta$-decay experiments, are a primary source of information for nuclear structure studies and at the same time complementary to in-beam investigations far from stability. Although both types of experiment are mainly based on $\\gamma$-ray spectroscopy, they face different experimental problems. The so-called $\\textit{Pandemonium effect}$ is a critical problem in $\\beta$-decay. In this contribution we will present a solution to this problem using total absorption spectroscopy methods. We will also present some examples of experiments carried out with the total absorption spectrometers TAS at GSI and Lucrecia recently installed at CERN. (25 refs).

  18. Beta-decay studies using total absorption techniques: some recent results

    Energy Technology Data Exchange (ETDEWEB)

    Algora, A.; Rubio, B.; Nacher, E.; Cano O, D.; Tain, J.L.; Gadea, A. [lnstituto de Fisica Corpuscular, Apartado Oficial 22085, 46071 Valencia (Spain); Batist, L.; Moroz, F.; Wittmann, V. [St. Petersburg Nuclear Physics Institute, RU-188-350 Gatchina, (Russian Federation); Borge, M.J.G.; Jungclaus, A.; Tengblad, O. [Instituto Estructura de la Materia, E-28006 Madrid (Spain); Collatz, R.; Hellstrom, M.; Kirchner, R.; Roeckl, E. [Gesellschaft fur Schwerionenforschung, D-64291 Darmstadt (Germany); Courtin, H.; Dessagne, Ph.; Miehe, C.; Marechal, F.; Poirier, E. [lnstitut de Recherches Subatomiques, IN2P3-CNRS, F-67037 Strassbourg Cedex 2 (France); Fraile, L.M. [ISOLDE, Division EP, CERN, CH-1211 Geneva (Switzerland); Gelletly, W. [University of Surrey, Guildford GU2 7XH (United Kingdom); Janas, Z.; Karny, M.; Rykaczewski, K. [University of Warsaw, PL-00-681, Warsaw (Poland); Le Scornet, G. [CSNSM, 91405 Orsay (France)

    2004-12-01

    Beta-decay experiments are a primary source of information for nuclear structure studies and at the same time complementary to in-beam investigations far from stability. Although both types of experiment are mainly based on {gamma} ray spectroscopy, they face different experimental problems. The so called Pandemonium effect [1] is a critical problem in {beta}-decay. In this contribution we will present a solution to this problem using total absorption spectroscopy methods. We will also present some examples of experiments carried out with the total absorption spectrometers TAS at GSI and Lucrecia recently installed at CERN. (Author) 25 refs., 4 figs.

  19. Study of octupole deformation in n-rich Ba isotopes populated via $\\beta$-decay

    CERN Multimedia

    We propose to exploit the unique capability of the ISOLDE facility to produce $^{150, 151, 152}$Cs beams to investigate their radioactive $\\beta$-decay to $^{150, 151, 152}$Ba. The interest to study this mass region is twofold: these nuclei are expected to show octupole deformations already in their low-lying state, secondly information on the $\\beta$-decay is needed for the nuclear astrophysical model. The experiment will be performed with the ISOLDE Decay Station (IDS) setup using the fast tape station of K.U.-Leuven, equipped with four Clover Germanium detectors, four LaBr$_{3}$(Ce) detectors and one LEP HPGe detector. Information on the $\\beta$-decay, such as lifetimes and delayed neutron-emission probabilities, will be extracted, together with the detailed spectroscopy of the daughter nuclei, via $\\gamma$-$\\gamma$-coincidences and lifetime measurement of specific states.

  20. Double beta decay: recent developments and projections

    International Nuclear Information System (INIS)

    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

  1. Shape coexistence in $^{180}$Hg studied through the $\\beta$ decay of $^{180}$Tl

    CERN Document Server

    Elseviers, J; Diriken, J; Patronis, N; Koster, U; Franchoo, S; Vermote, S; Bree, N; Veselsky, M; Huyse, M; Cocolios, T E; Seliverstov, M; Barzakh, A; Van Duppen, P; Venhart, M; Van den Bergh, P; Page, R D; Marsh, B A; Wagemans, C; Heredia, J A; Ivanov, O; Comas, V F; Van De Walle, J; Antalic, S; Fedosseyev, V N; Fedorov, D; Andreyev, A N

    2011-01-01

    The beta(+)/EC decay of (180)Tl and excited states in the daughter nucleus (180)Hg have been investigated at the CERN On-Line Isotope Mass Separator (ISOLDE) facility. Many new low-lying energy levels were observed in (180)Hg, of which the most significant are the 0(2)(+) at 419.6 keV and the 2(2)(+) at 601.3 keV. The former is the bandhead of an excited band in (180)Hg assumed originally to be of prolate nature. From the beta feeding to the different states in (180)Hg, the ground-state spin of (180)Tl was deduced to be (4(-),5(-)).

  2. Construction of a 1 MeV Electron Accelerator for High Precision Beta Decay Studies

    Science.gov (United States)

    Longfellow, Brenden

    2014-09-01

    Beta decay energy calibration for detectors is typically established using conversion sources. However, the calibration points from conversion sources are not evenly distributed over the beta energy spectrum and the foil backing of the conversion sources produces perturbations in the calibration spectrum. To improve this, an external, tunable electron beam coupled by a magnetic field can be used to calibrate the detector. The 1 MeV electron accelerator in development at Triangle Universities Nuclear Laboratory (TUNL) utilizes a pelletron charging system. The electron gun shoots 104 electrons per second with an energy range of 50 keV to 1 MeV and is pulsed at a 10 kHz rate with a few ns width. The magnetic field in the spectrometer is 1 T and guiding fields of 0.01 to 0.05 T for the electron gun are used to produce a range of pitch angles. This accelerator can be used to calibrate detectors evenly over its energy range and determine the detector response over a range of pitch angles. Beta decay energy calibration for detectors is typically established using conversion sources. However, the calibration points from conversion sources are not evenly distributed over the beta energy spectrum and the foil backing of the conversion sources produces perturbations in the calibration spectrum. To improve this, an external, tunable electron beam coupled by a magnetic field can be used to calibrate the detector. The 1 MeV electron accelerator in development at Triangle Universities Nuclear Laboratory (TUNL) utilizes a pelletron charging system. The electron gun shoots 104 electrons per second with an energy range of 50 keV to 1 MeV and is pulsed at a 10 kHz rate with a few ns width. The magnetic field in the spectrometer is 1 T and guiding fields of 0.01 to 0.05 T for the electron gun are used to produce a range of pitch angles. This accelerator can be used to calibrate detectors evenly over its energy range and determine the detector response over a range of pitch angles

  3. Beta decay rates of neutron-rich nuclei

    Science.gov (United States)

    Marketin, Tomislav; Huther, Lutz; Petković, Jelena; Paar, Nils; Martínez-Pinedo, Gabriel

    2016-06-01

    Heavy element nucleosynthesis models involve various properties of thousands of nuclei in order to simulate the intricate details of the process. By necessity, as most of these nuclei cannot be studied in a controlled environment, these models must rely on the nuclear structure models for input. Of all the properties, the beta-decay half-lives are one of the most important ones due to their direct impact on the resulting abundance distributions. In this study we present the results of a large-scale calculation based on the relativistic nuclear energy density functional, where both the allowed and the first-forbidden transitions are studied in more than 5000 neutron-rich nuclei. Aside from the astrophysical applications, the results of this calculation can also be employed in the modeling of the electron and antineutrino spectra from nuclear reactors.

  4. Beta decay rates of neutron-rich nuclei

    International Nuclear Information System (INIS)

    Marketin, Tomislav; Petković, Jelena; Paar, Nils; Huther, Lutz; Martínez-Pinedo, Gabriel

    2016-01-01

    Heavy element nucleosynthesis models involve various properties of thousands of nuclei in order to simulate the intricate details of the process. By necessity, as most of these nuclei cannot be studied in a controlled environment, these models must rely on the nuclear structure models for input. Of all the properties, the beta-decay half-lives are one of the most important ones due to their direct impact on the resulting abundance distributions. In this study we present the results of a large-scale calculation based on the relativistic nuclear energy density functional, where both the allowed and the first-forbidden transitions are studied in more than 5000 neutron-rich nuclei. Aside from the astrophysical applications, the results of this calculation can also be employed in the modeling of the electron and antineutrino spectra from nuclear reactors.

  5. Beta decay rates of neutron-rich nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Marketin, Tomislav, E-mail: marketin@phy.hr; Petković, Jelena; Paar, Nils [Department of Physics, Faculty of Science, University of Zagreb, 10000 Zagreb (Croatia); Huther, Lutz [Institut für Kernphysik (Theoriezentrum), Technische Universität Darmstadt, 64289 Darmstadt (Germany); Martínez-Pinedo, Gabriel [Institut für Kernphysik (Theoriezentrum), Technische Universität Darmstadt, 64289 Darmstadt (Germany); GSI Helmholtzzentrum für Schwerioneneforschung, Planckstraße 1, 64291 Darmstadt (Germany)

    2016-06-21

    Heavy element nucleosynthesis models involve various properties of thousands of nuclei in order to simulate the intricate details of the process. By necessity, as most of these nuclei cannot be studied in a controlled environment, these models must rely on the nuclear structure models for input. Of all the properties, the beta-decay half-lives are one of the most important ones due to their direct impact on the resulting abundance distributions. In this study we present the results of a large-scale calculation based on the relativistic nuclear energy density functional, where both the allowed and the first-forbidden transitions are studied in more than 5000 neutron-rich nuclei. Aside from the astrophysical applications, the results of this calculation can also be employed in the modeling of the electron and antineutrino spectra from nuclear reactors.

  6. Main features of detectors and isotopes to investigate double beta decay with increased sensitivity

    Science.gov (United States)

    Barabash, A. S.

    2018-03-01

    The current situation in double beta decay experiments, the characteristics of modern detectors and the possibility of increasing the sensitivity to neutrino mass in future experiments are discussed. The issue of the production and use of enriched isotopes in double beta decay experiments is discussed in addition.

  7. Double beta decay and majorana neutrinos. Right-handed currents or nonzero masses

    International Nuclear Information System (INIS)

    Rosen, S.P.; Perlmutter, A.

    1981-01-01

    This chapter describes some new developments concerning the mechanism for lepton number nonconservation in no-neutrino double beta decay. Explains that lepton number nonconservation in no-neutrino double beta decay comes about either because both left- and right-handed components of a Majorano neutrino are coupled to the electron in the weak leptonic current, or because the neutrino has nonzero mass. Shows that while nuclear ground-state to ground-state transitions arise from right-handed currents and from neutrino mass terms, transitions to low-lying excited states with J /SUP P/ =2 + can arise only from right-handed currents. Emphasizes that the possibilities of detecting small admixtures of right-handed currents, and of setting limits on neutrino masses that are either very small or very large, make double beta decay a most rewarding phenomenon to study

  8. Double beta decay and neutrino mass models

    Energy Technology Data Exchange (ETDEWEB)

    Helo, J.C. [Universidad Técnica Federico Santa María, Centro-Científico-Tecnológico de Valparaíso, Casilla 110-V, Valparaíso (Chile); Hirsch, M. [AHEP Group, Instituto de Física Corpuscular - C.S.I.C./Universitat de València, Edificio de Institutos de Paterna, Apartado 22085, E-46071 València (Spain); Ota, T. [Department of Physics, Saitama University, Shimo-Okubo 255, 338-8570 Saitama-Sakura (Japan); Santos, F.A. Pereira dos [Departamento de Física, Pontifícia Universidade Católica do Rio de Janeiro,Rua Marquês de São Vicente 225, 22451-900 Gávea, Rio de Janeiro (Brazil)

    2015-05-19

    Neutrinoless double beta decay allows to constrain lepton number violating extensions of the standard model. If neutrinos are Majorana particles, the mass mechanism will always contribute to the decay rate, however, it is not a priori guaranteed to be the dominant contribution in all models. Here, we discuss whether the mass mechanism dominates or not from the theory point of view. We classify all possible (scalar-mediated) short-range contributions to the decay rate according to the loop level, at which the corresponding models will generate Majorana neutrino masses, and discuss the expected relative size of the different contributions to the decay rate in each class. Our discussion is general for models based on the SM group but does not cover models with an extended gauge. We also work out the phenomenology of one concrete 2-loop model in which both, mass mechanism and short-range diagram, might lead to competitive contributions, in some detail.

  9. Neutrinoless double beta decay search with SNO+

    Directory of Open Access Journals (Sweden)

    Lozza V.

    2014-01-01

    Full Text Available 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.

  10. Double beta decay in gauge theories

    International Nuclear Information System (INIS)

    Vergados, J.D.

    2002-01-01

    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 j L - j R 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 . (author)

  11. The empirical connection between (p,n) cross sections and beta decay transition strengths

    International Nuclear Information System (INIS)

    Taddeucci, T.N.

    1988-01-01

    A proportionality is assumed to exist between 0/degree/ (p,n) cross sections and the corresponding beta decay transition strengths. The validity of this assumption is tested by comparison of measured (p,n) cross sections and analogous beta decay strengths. Distorted waves impulse approximation calculations also provide useful estimates of the accuracy of the proportionality relationship. 14 refs., 10 figs

  12. Beta-decay 125I → 125Te

    Directory of Open Access Journals (Sweden)

    A. A. Kurteva

    2016-08-01

    Full Text Available Beta-decay of the nucleus 125I and spectroscopic characteristics of the daughter nucleus are described within the framework of the dynamic collective model. Quasiparticle and multiphonon states, as well as vacuum fluctuations of quasiparticles are taken into account. The comparison of the results of calculations with the available experimental data is performed.

  13. Double beta decays and neutrino masses

    International Nuclear Information System (INIS)

    Ejiri, Hiro

    2006-01-01

    Neutrino-less double beta decays(0νββ) are of great interest for studying the Majorana nature of ν's and the absolute ν-mass scale. The present report is a brief review of the 0νββ studies with emphasis on future experiments with the mass sensitivity of an order of 25∼100 meV and on experimental probes for investigating 0νββ nuclear matrix elements

  14. Study of the ${\\beta}$-decay of $^{12}$B

    CERN Multimedia

    2002-01-01

    We propose to study the ${\\beta}$-decay of $^{12}$B with a modern segmented Si-detector array to get new and much improved information on states in $^{12}$C above the ${\\alpha}$-threshold. These states mainly decay into final states of three ${\\alpha}$-particles and their study therefore is a challenge for nuclear spectroscopy. The properties of these states is of high current interest for nuclear astrophysics and for the nuclear many-body problem in general. We ask for a total of 15 shifts.

  15. First test of an enriched {sup 116}CdWO{sub 4} scintillating bolometer for neutrinoless double-beta-decay searches

    Energy Technology Data Exchange (ETDEWEB)

    Barabash, A.S.; Konovalov, S.I.; Umatov, V.I. [ITEP, National Research Centre ' ' Kurchatov Institute' ' , Moscow (Russian Federation); Danevich, F.A. [MSP, Institute for Nuclear Research, Kyiv (Ukraine); Gimbal-Zofka, Y. [Univ. Paris-Sud, CNRS/IN2P3, Universite Paris-Saclay, CSNSM, Orsay (France); Linnaeus University, Department of Physics and Electrical Engineering, Kalmar (Sweden); Giuliani, A.; Mancuso, M. [Univ. Paris-Sud, CNRS/IN2P3, Universite Paris-Saclay, CSNSM, Orsay (France); DISAT, Universita dell' Insubria, Como (Italy); Marcillac, P. de; Marnieros, S.; Novati, V.; Olivieri, E. [Univ. Paris-Sud, CNRS/IN2P3, Universite Paris-Saclay, CSNSM, Orsay (France); Nones, C.; Zolotarova, A.S. [DSM/IRFU, CEA Saclay, Gif-sur-Yvette Cedex (France); Poda, D.V. [MSP, Institute for Nuclear Research, Kyiv (Ukraine); Univ. Paris-Sud, CNRS/IN2P3, Universite Paris-Saclay, CSNSM, Orsay (France); Shlegel, V.N. [Nikolaev Institute of Inorganic Chemistry, Novosibirsk (Russian Federation); Tretyak, V.I. [MSP, Institute for Nuclear Research, Kyiv (Ukraine); INFN, Sezione di Roma, Rome (Italy)

    2016-09-15

    For the first time, a cadmium tungstate crystal scintillator enriched in {sup 116}Cd has been succesfully tested as a scintillating bolometer. The measurement was performed above ground at a temperature of 18 mK. The crystal mass was 34.5 g and the enrichment level ∝ 82 %. Despite a substantial pile-up effect due to above-ground operation, the detector demonstrated high energy resolution (2-7 keV FWHM in 0.2-2.6 MeV γ energy range and 7.5 keV FWHM at the {sup 116}Cd double-beta decay transition energy of 2813 keV), a powerful particle identification capability and a high level of internal radio-purity. These results prove that cadmium tungstate is a promising detector material for a next-generation neutrinoless double-beta decay bolometric experiment, like that proposed in the CUPID project (CUORE Upgrade with Particle IDentification). (orig.)

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

    Energy Technology Data Exchange (ETDEWEB)

    Ackerman, N.; /SLAC; Aharmim, B.; /Laurentian U.; Auger, M.; /Bern U.; Auty, D.J.; /Alabama U.; Barbeau, P.S.; Barry, K.; Bartoszek, L.; /Stanford U., Phys. Dept.; Beauchamp, E.; /Laurentian U.; Belov, V.; /Moscow, ITEP; Benitez-Medina, C.; /Colorado State U.; Breidenbach, M.; /SLAC; Burenkov, A.; /Moscow, ITEP; Cleveland, B.; /Laurentian U.; Conley, R.; Conti, E.; /SLAC; Cook, J.; /Massachusetts U., Amherst; Cook, S.; /Colorado State U.; Coppens, A.; /Carleton U.; Counts, I.; /Stanford U., Phys. Dept.; Craddock, W.; /SLAC; Daniels, T.; /Massachusetts U., Amherst /Moscow, ITEP /Maryland U. /Stanford U., Phys. Dept. /Alabama U. /Maryland U. /Moscow, ITEP /Stanford U., Phys. Dept. /Laurentian U. /Carleton U. /Colorado State U. /Laurentian U. /Munich, Tech. U. /Bern U. /SLAC /Bern U. /Carleton U. /Stanford U., Phys. Dept. /Carleton U. /Maryland U. /Colorado State U. /SLAC /Carleton U. /SLAC /Alabama U. /SLAC /Moscow, ITEP /Indiana U. /Stanford U., Phys. Dept. /Moscow, ITEP /Stanford U., Phys. Dept. /Massachusetts U., Amherst /Seoul U. /Carleton U. /Stanford U., Phys. Dept.; /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.

  17. Generalized Solutions of the Dirac Equation, W Bosons, and Beta Decay

    International Nuclear Information System (INIS)

    Okniński, Andrzej

    2016-01-01

    We study the 7×7 Hagen-Hurley equations describing spin 1 particles. We split these equations, in the interacting case, into two Dirac equations with nonstandard solutions. It is argued that these solutions describe decay of a virtual W boson in beta decay.

  18. Semiconductor-based experiments for neutrinoless double beta decay search

    International Nuclear Information System (INIS)

    Barnabé Heider, Marik

    2012-01-01

    Three experiments are employing semiconductor detectors in the search for neutrinoless double beta (0νββ) decay: COBRA, Majorana and GERDA. COBRA is studying the prospects of using CdZnTe detectors in terms of achievable energy resolution and background suppression. These detectors contain several ββ emitters and the most promising for 0νββ-decay search is 116 Cd. Majorana and GERDA will use isotopically enriched high purity Ge detectors to search for 0νββ-decay of 76 Ge. Their aim is to achieve a background ⩽10 −3 counts/(kg⋅y⋅keV) at the Q improvement compared to the present state-of-art. Majorana will operate Ge detectors in electroformed-Cu vacuum cryostats. A first cryostat housing a natural-Ge detector array is currently under preparation. In contrast, GERDA is operating bare Ge detectors submerged in liquid argon. The construction of the GERDA experiment is completed and a commissioning run started in June 2010. A string of natural-Ge detectors is operated to test the complete experimental setup and to determine the background before submerging the detectors enriched in 76 Ge. An overview and a comparison of these three experiments will be presented together with the latest results and developments.

  19. Study of 193Os beta- decay

    International Nuclear Information System (INIS)

    Zahn, Guilherme Soares

    2006-01-01

    In this work, the excited levels of 193 Ir populated by the beta - decay of 193 Os (T 1/2 ∼ 30h) were investigated. For that purpose, ∼ 5 mg samples of 99%-enriched 192 Os were irradiated under a thermal neutron flux of ∼ 10 12 s -1 and then analysed both using single gamma spectroscopy and a 4-detector multi parametric acquisition facility, which provided data for both a gamma gamma coincidence analysis and a directional angular correlation gamma gamma (θ ) study. From these data, 28 transitions were added to this decay scheme, 11 of which were previously known from nuclear reactions and 17 observed for the first time. Eight excited levels were also added to the decay scheme, 3 of which were known from nuclear reaction studies - the remaining 5 are suggested for the first time. Moreover, it was possible to confirm suspicions found in reference that the levels at 848.93 keV and 849.093 keV are indeed the same; it was also possible to confirm the existence of an excited level at 806.9 keV, which had been inferred, but not experimentally confirmed in beta decay studies to date. The angular correlation analysis allowed for the definition of the spin of the excited level at 874 keV as 5/2 +; moreover, the results showed a 79% probability that the spin of the 1078 keV level is 5/2/'-, and also restricted the spin possibilities for the new excited level at 960 keV to two values (1/2 or 3/2). It was also possible to measure the multipolarity mixing ratio (δ Ln+1 /L n ) for 43 transitions - 19 of them for the first time and most of the others with a better precision than previously known. Finally, an attempt was made to understand the low-lying levels structure for this nucleus using a theoretical model, which reproduced the ground state and the two lowest-lying excited levels in 193 Ir. (author)

  20. Double beta decay searches with thermal detectors

    International Nuclear Information System (INIS)

    Pirro, Stefano

    2006-01-01

    Double beta decay searches have become more and more important in the last few years. The 'second generation' experiments will allow to explore the inverse hierarchy region but, due to the uncertainties in the nuclear matrix elements, none of them will be able to cover completely the allowed region. Thus the need to investigate different DBD emitters becomes more important. The bolometric technique is only one able to study different nuclei with the proper energy resolution, key point for the future experiments. The possibility to reject the natural background arising from fast neutrons and alpha particles was recently directly proved with thermal bolometers, using the double read out (heat and scintillation). This new technique offers the possibility to reach background levels two orders of magnitude smaller with respect to the ones of the next planned experiments, aiming the possibility to investigate direct hierarchy region. (author)

  1. Beta decay of {sup 97}Ag: evidence for the Gamow-Teller resonance near {sup 100}Sn

    Energy Technology Data Exchange (ETDEWEB)

    Hu Zhiqiang

    1999-03-01

    In two complementary measurements, a cube like array of 6 Euroball-Cluster germanium detectors and a total-absorption {gamma}-spectrometer were used to investigate the {beta} decay of {sup 97}Ag, a three proton-hole nucleus with respect to the {sup 100}Sn core. The half-life and Q{sub EC} value of the decay of the 9/2{sup +} ground-state of {sup 97}Ag were determined to be 25.9(4) s and 6.98(11) MeV respectively. A total of 603 {gamma} rays (578 new) was observed, and 151 levels (132 new) in {sup 97}Pd have been identified. An interesting {beta}-delayed {gamma} cascade was observed, which comprises 6 {gamma}-transitions with a de-excitation pattern involving an initial increase of the level spin. The Gamow-Teller (GT) {beta}-decay strength distributions from the two measurements reveal a large GT resonance around 4 MeV with a width of about 1.8 MeV. The hindrance factor for the total GT strength summed from the ground-state up to 6 MeV excitation energy in {sup 97}Pd, amounts to 4.3(6) with reference to a shell-model prediction. This factor is discussed in comparison with a core-polarization and a Monte-Carlo shell-model calculation. (orig.)

  2. Precision measurement of the half-life and the $\\beta$-decay Q value of the superallowed 0$^{+}\\rightarrow$ 0$^{+}\\beta$-decay of $^{38}$Ca

    CERN Multimedia

    2002-01-01

    We propose to study the $\\beta$-decay of $^{38}$Ca. In a first instance, we intend to perform a high-precision study of the half-life of this nucleus as well as a measurement of its $\\beta$-decay Q-value with ISOLTRAP. At a later stage, we propose to study its decay branches to determine the super-allowed branching ratio with high precision. These measurements are essential to improve our understanding of the theoretical corrections (in particular the $\\delta$c correction factor) needed to calculate the universal Ft value from the ft value determined for individual nuclei. For this nucleus, the correction factor is predicted to increase significantly as compared to the nine well-studied nuclei between $^{10}$C and $^{54}$Co and the model calculations used to determine the corrections, in particular the shell-model calculations, are well under control in this mass region. Therefore, the T$_{Z}$= -1 nuclei between A=18 and A=38 are ideal test cases for the correction factors which limit today the precision on t...

  3. The MAJORANA DEMONSTRATOR: A Search for Neutrinoless Double-beta Decay of Germanium-76

    Energy Technology Data Exchange (ETDEWEB)

    Schubert, Alexis G.; Aguayo, Estanislao; Avignone, F. T.; Zhang, C.; 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.; Leon, Jonathan D.; 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.; Guiseppe, Vincente; Gusey, K.; Hallin, A. L.; Hazama, R.; Henning, Reyco; Hime, Andrew; Hoppe, Eric W.; Horton, Mark; Howard, Stanley; Howe, Mark; 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.; LaFerriere, Brian D.; LaRoque, B. H.; 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, D.; Poon, Alan; Perumpilly, Gopakumar; Prior, Gersende; Radford, D. C.; Rielage, Keith; Robertson, R. G. H.; Ronquest, M. C.; Shima, T.; Shirchenko, M.; Snavely, Kyle J.; Sobolev, V.; Steele, David; Strain, J.; Thomas, K.; Timkin, V.; Tornow, Werner; 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

    2012-09-28

    The observation of neutrinoless double-beta decay would determine whether the neutrino is a Majorana particle and provide information on the absolute scale of neutrino mass. The MAJORANA Collaboration is constructing the DEMONSTRATOR, an array of germanium detectors, to search for neutrinoless double-beta decay of 76Ge. The DEMONSTRATOR will contain 40 kg of germanium; up to 30 kg will be enriched to 86% in 76Ge. The DEMONSTRATOR will be deployed deep underground in an ultra-low-background shielded environment. Operation of the DEMONSTRATOR aims to determine whether a future tonne-scale germanium experiment can achieve a background goal of one count per tonne-year in a 4-keV region of interest around the 76Ge neutrinoless double-beta decay Q-value of 2039 keV.

  4. Double beta decay in the generalized seniority scheme

    International Nuclear Information System (INIS)

    Pittel, S.; Engel, J.; Vogel, P.; Ji Xiangdong

    1990-01-01

    A generalized-seniority truncation scheme is used in shell-model calculations of double beta decay matrix elements. Calculations are carried out for 78 Ge, 82 Se and 128,130 Te. Matrix elements calculated for the two-neutrino decay mode are small compared to weak-coupling shell-model calculations and support the suppression mechanism first observed in the quasi-particle random phase approximation. Matrix elements for the neutrinoless mode are similar to those of the weak-coupling shell model, suggesting that these matrix elements can be pinned down fairly accurately. (orig.)

  5. $\\beta$-decay study of neutron-rich Tl and Pb isotopes

    CERN Multimedia

    It is proposed to study the structure of neutron-rich nuclei beyond $^{208}$Pb. The one-proton hole $^{211-215}$Tl and the semi magic $^{213}$Pb will be produced and studied via nuclear and atomic spectroscopy searching for long-lived isomers and investigating the $\\beta$-delayed $\\gamma$- emission to build level schemes. Information on the single particle structure in $^{211-215}$Pb, especially the position of the g$_{9/2}$ and i$_{11/2}$ neutron orbitals, will be extracted along with lifetimes. The $\\beta$-decay will be complemented with the higher spin selectivity that can be obtained by resonant laser ionization to single-out the decay properties of long-living isomers in $^{211,213}$Tl and $^{213}$Pb.

  6. Double-beta decay with majoron emission in GERDA Phase I

    Science.gov (United States)

    Hemmer, Sabine

    2015-07-01

    Neutrinoless double-beta decay with emission of one or two majorons (0 νββχ( χ)) is predicted by several beyond-Standard-Model theories. This article reviews the results of a search for 0 νββχ( χ) of 76Ge using data from the Germanium Detector Array (GERDA) experiment, located underground at the INFN Laboratori Nazionali del Gran Sasso (LNGS) in Italy. The analysis comprised data with an exposure of 20.3 kg·yr from the first phase of the experiment. No indication of contributions to the observed energy spectra was detected for any of the majoron models. The lower limit on the half-life for the ordinary majoron model (spectral index n = 1 was determined to be T {1/2/0 νβ } > 4.2 · 1023 yr (90% quantile). This limit and the limits derived for the other majoron modes constitute the most stringent limits on 0 νββχ( χ) decay of 76Ge measured to date.

  7. Results on Neutrinoless Double-Beta Decay from Gerda Phase I

    Science.gov (United States)

    Macolino, Carla

    2014-12-01

    The GERmanium Detector Array, GERDA, is designed to search for neutrinoless double-beta (0νββ) decay of 76Ge and it is installed in the Laboratori Nazionali del Gran Sasso (LNGS) of INFN, Italy. In this review, the detection principle and detector setup of GERDA are described. Also, the main physics results by GERDA Phase I, are discussed. They include the measurement of the half-life of 2νββ decay, the background decomposition of the energy spectrum and the techniques for the discrimination of the background, based on the pulse shape of the signal. In the last part of this review, the estimation of a limit on the half-life of 0νββ (T0ν 1/2>2.1ḑot 1025 yr at 90% C.L.) and the comparison with previous results are discussed. GERDA data from Phase I strongly disfavor the recent claim of 0νββ discovery, based on data from the Heidelberg-Moscow experiment.

  8. Recent status of the studies of nuclear masses and {beta}-decay

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, Masami [Waseda Univ., Tokyo (Japan). Advanced Research Center for Science and Engineering

    1996-05-01

    The recent status of the above studies was explained, especially, nuclear masses were described from the aspect of probability theory and that of {beta}-decay suggested that the first forbidden transition was hindered between the ground states. We have to study various systematics in order to know the mass surface, Way-Yamada-Matumoto type systematics is better to check the experimental nuclear masses. The gross theory is very useful to understand the general aspect of {beta}-decay. The understanding method of mass surface, systematic check of mass and hindrance of the first forbidden transition at rank 1 were explained. (S.Y.)

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

    Directory of Open Access Journals (Sweden)

    D. R. Artusa

    2015-01-01

    Full Text Available Neutrinoless double-beta (0νββ 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 0νββ decay of 130Te using an array of 988 TeO2 crystal bolometers operated at 10 mK. The detector will contain 206 kg of 130Te and have an average energy resolution of 5 keV; the projected 0νββ decay half-life sensitivity after five years of livetime 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. In this paper, we review the experimental techniques used in CUORE as well as its current status and anticipated physics reach.

  10. Spectral shapes and a beta-gamma directional correlation in the beta decay of 172Tm (Jpi = 2-)

    DEFF Research Database (Denmark)

    Gregers Hansen, P.; Loft Nielsen, H.; Wilsky, K.

    1966-01-01

    The isotope 172Tm populates the 0+, 2+ and 4+ states of the 172Yb ground-state rotational band directly in beta decay. The shapes and intensities of the three beta groups have been measured by means of a six-gap magnetic spectrometer operated in coincidence with a Nal(Tl) crystal. The experimenta...

  11. The Majorana Double Beta Decay Experiment: Present Status

    Energy Technology Data Exchange (ETDEWEB)

    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

  12. The relative importance of relativistic induced interactions in the beta decay of 170Tm

    International Nuclear Information System (INIS)

    Bogdan, D.; Cristu, M.I.; Holan, S.; Faessler, A.

    1982-09-01

    The log ft-values, the spectrum shape functions, and the beta-gamma angular correlation coefficients of the 170 Tm beta decay are computed in the framework of relativistic formfactor formalism using asymmetric rotor model wavefunctions. Main vector and axial vector hadron currents being strongly hindered, the relative importance of induced interaction matrix elements is accurately estimated. Good agreement with experiment is obtained for the beta decay observables when the main induced interaction terms were taken into account. The contribution of the pseudoscalar term was found insignificant. (authors)

  13. Consistency check of pulse shape discrimination for broad energy germanium detectors using double beta decay data

    Energy Technology Data Exchange (ETDEWEB)

    Liao, Heng-Ye [Max-Planck-Institut fuer Physik, Muenchen (Germany); Collaboration: GERDA-Collaboration

    2013-07-01

    The Gerda (GERmanium Detector Array) experiment was built to study fundamental neutrino properties via neutrinoless double beta decay (0νββ). 0νββ events are single-site events (SSE) confined to a scale about millimeter. However, most of backgrounds are multi-site events (MSE). Broad Energy Germanium detectors (BEGes) offer the potential merits of improved pulse shape recognition efficiencies of SSE/MSE. They allow us to reach the goal of Phase II with a background index of 10{sup -3} cts/(keV.kg.yr) in the ROI. BEGe detectors with a total target mass of 3.63 kg have been installed to the Gerda setup in the Laboratori Nazionali del Gran Sasso (LNGS) in July 2012 and are collecting data since. A consistency check of the pulse shape discrimination (PSD) efficiencies by comparison of calibration data and 2νββ data will be presented. The PSD power of these detectors is demonstrated.

  14. Sensitivity and Discovery Potential of CUORE to Neutrinoless Double-Beta Decay

    Energy Technology Data Exchange (ETDEWEB)

    Alessandria, F; Ardito, R; Artusa, DR; III, FTA; Azzolini, O; Balata, M; Banks, TI; Bari, G; Beeman, J; Bellini, F; Bersani, A; Biassoni, M; Bloxham, T; Brofferio, C; Bucci, C; Cai, XZ; Canonica, L; Cao, X; Capelli, S; Carbone, L; Cardani, L; Carrettoni, M; Casali, N; Chiesa, D; Chott, N; Clemenza, M; Cosmelli, C; Cremonesi, O; Creswick, RJ; Dafinei, I; Dally, A; Datskov, V; Biasi, AD; Deninno, MM; Domizio, SD; Vacri, MLD; Ejzak, L; Faccini, R; Fang, DQ; Farach, HA; Faverzani, M; Fernandes, G; Ferri, E; Ferroni, F; Fiorini, E; Franceschi, MA; Freedman, SJ; Fujikawa, BK; Giachero, A; Gironi, L; Giuliani, A; Goett, J; Gorla, P; Gotti, C; Guardincerri, E; Gutierrez, TD; Haller, EE; Han, K; Heeger, KM; Huang, HZ; Kadel, R; Kazkaz, K; Keppel, G; Kogler, L; Kolomensky, YG; Lenz, D; Li, YL; Ligi, C; Liu, X; Ma, YG; Maiano, C; Maino, M; Martinez, M; Maruyama, RH; Mei, Y; Moggi, N; Morganti, S; Napolitano, T; Newman, S; Nisi, S; Nones, C; Norman, EB; Nucciotti, A; O' Donnell, T; Orio, F; Orlandi, D; Ouellet, JL; Pallavicini, M; Palmieri, V; Pattavina, L; Pavan, M; Pedretti, M; Pessina, G; Piperno, G; Pirro, S; Previtali, E; Rampazzo, V; Rimondi, F; Rosenfeld, C; Rusconi, C; Sala, E; Sangiorgio, S; Scielzo, ND; Sisti, M; Smith, AR; Stivanello, F; Taffarello, L; Tenconi, M; Tian, WD; Tomei, C; Trentalange, S; Ventura, G; Vignati, M; Wang, BS; Wang, HW; Wise, T; Woodcraft, A; Zanotti, L; Zarra, C; Zhu, BX; Zucchelli, S

    2017-07-06

    We present a study of the sensitivity and discovery potential of CUORE, a bolometric double-beta decay experiment under construction at the Laboratori Nazionali del Gran Sasso in Italy. Two approaches to the computation of experimental sensitivity for various background scenarios are presented, and an extension of the sensitivity formulation to the discovery potential case is also discussed. Assuming a background rate of 10-2 cts/(keV kg y), we find that, after 5 years of live time, CUORE has a 1 sigma sensitivity to the neutrinoless double-beta decay half-life of T$0v\\atop{1/2}$(1θ) = 1.6 \\times 1026 y and thus a potential to probe the effective Majorana neutrino mass down to 40-100 meV; the sensitivity at 1.64 sigma, which corresponds to 90% C.L., will be T$0v\\atop{1/2}$(1.64θ) = 9.5 \\times 1025 y. This range is compared with the claim of observation of neutrinoless double-beta decay in 76Ge and the preferred range of the neutrino mass parameter space from oscillation results.

  15. Beta-energy averaging and beta spectra

    International Nuclear Information System (INIS)

    Stamatelatos, M.G.; England, T.R.

    1976-07-01

    A simple yet highly accurate method for approximately calculating spectrum-averaged beta energies and beta spectra for radioactive nuclei is presented. This method should prove useful for users who wish to obtain accurate answers without complicated calculations of Fermi functions, complex gamma functions, and time-consuming numerical integrations as required by the more exact theoretical expressions. Therefore, this method should be a good time-saving alternative for investigators who need to make calculations involving large numbers of nuclei (e.g., fission products) as well as for occasional users interested in restricted number of nuclides. The average beta-energy values calculated by this method differ from those calculated by ''exact'' methods by no more than 1 percent for nuclides with atomic numbers in the 20 to 100 range and which emit betas of energies up to approximately 8 MeV. These include all fission products and the actinides. The beta-energy spectra calculated by the present method are also of the same quality

  16. A detection system for very low-energy protons from β-delayed proton decay

    International Nuclear Information System (INIS)

    Spiridon, A.; Pollacco, E.; Trache, L.; Simmons, E.; McCleskey, M.; Roeder, B. T.; Tribble, R. E.; Pascovici, G.; Riallot, M.; Mols, J. P.; Kebbiri, M.

    2012-01-01

    We have recently developed a gas based detection system called AstroBox, motivated by nuclear astrophysics studies. The goal was to detect very low-energy protons from β-delayed p-decay with reduced beta background and improved energy resolution. The detector was tested using the β-delayed proton-emitter 23Al previously studied with a set-up based on thin double-sided Si strip detectors. The proton spectrum obtained with AstroBox showed no beta background down to ∼80 keV. The low energy (206 keV, 267 keV) proton peaks were positively identified, well separated, and the resolution was improved.

  17. New developments in the calculation of double beta decay

    International Nuclear Information System (INIS)

    Engel, J.

    1990-01-01

    I review recent work on computing double beta decay rates. After a discussion of shell model and Quasiparticle Random Phase calculations, I argue for a model based on the notion of generalized seniority that combines the advantages of both earlier approaches. (orig.)

  18. The double beta decay spectrum of 100Mo as measured with a TPC

    International Nuclear Information System (INIS)

    Elliott, S.R.; Moe, M.K.; Nelson, M.A.; Vient, M.A.

    1991-01-01

    A time projection chamber with 8.3 grams of enriched 100 MoO 3 as the central electrode has been operating approximately five months in an underground laboratory. A preliminary analysis of the two-electron sum energy spectrum, the spectrum of those same electrons taken singly, and the opening angle distribution yields a half life of 1.16 -0.08 +0.34 x10 19 y at the 68% confidence level for two-neutrino double beta decay of 100 Mo. (author)

  19. Warm Dark Matter Sterile Neutrinos in Electron Capture and Beta Decay Spectra

    Directory of Open Access Journals (Sweden)

    O. Moreno

    2016-01-01

    Full Text Available We briefly review the motivation to search for sterile neutrinos in the keV mass scale, as dark matter candidates, and the prospects to find them in beta decay or electron capture spectra, with a global perspective. We describe the fundamentals of the neutrino flavor-mass eigenstate mismatch that opens the possibility of detecting sterile neutrinos in such ordinary nuclear processes. Results are shown and discussed for the effect of heavy neutrino emission in electron capture in Holmium 163 and in two isotopes of Lead, 202 and 205, as well as in the beta decay of Tritium. We study the deexcitation spectrum in the considered cases of electron capture and the charged lepton spectrum in the case of Tritium beta decay. For each of these cases, we define ratios of integrated transition rates over different regions of the spectrum under study and give new results that may guide and facilitate the analysis of possible future measurements, paying particular attention to forbidden transitions in Lead isotopes.

  20. Electromagnetically induced nuclear beta decay calculated by a Green's function method

    International Nuclear Information System (INIS)

    Reiss, H.R.

    1984-01-01

    The transition probability for enhancement of forbidden nuclear beta decay by an applied plane-wave electromagnetic field is calculated in a nonrelativistic spinless approximation by a Green's function method. The calculation involves a stationary-phase approximation. The stationary phase points in the presence of an intense field are located in very different positions than they are in the field-free case. In order-of-magnitude terms, the results are completely consistent with an earlier, much more complete wave-function calculation which includes spin and relativistic effects. Both the present Green's function calculation and the earlier wave function calculation give electromagnetic contributions in first-forbidden nuclear beta decay matrix elements which are of order (R 0 /lambda-dash-bar/sub C/) 2 with respect to allowed decays, where R 0 is the nuclear radius and lambda-dash-bar/sub C/ is the electron Compton wavelength

  1. Beta asymmetry parameter in the decay of In-114

    Czech Academy of Sciences Publication Activity Database

    Wauters, F.; De Leebeeck, V.; Kraev, I.; Tandecki, M.; Traykov, E.; Van Gorp, S.; Severijns, N.; Zákoucký, Dalibor

    2009-01-01

    Roč. 80, č. 6 (2009), 062501/1-062501/5 ISSN 0556-2813 Institutional research plan: CEZ:AV0Z10480505 Keywords : beta decay * left -right asymmetry * nuclear oreintation Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 3.477, year: 2009

  2. Nuclear decay data measurements at the INEL ISOL facility

    International Nuclear Information System (INIS)

    Greenwood, R.C.; Helmer, R.G.; Putnam, M.H.; Struttmann, D.A.; Watts, K.D.

    1991-01-01

    In recent years, the use of the mass separation technique coupled on-line to a source of fission product nuclides has provided a wealth of new information on the nuclear decay properties of such nuclides. In addition to their relevance in basic studies of nuclear properties of neutron-rich nuclei, the fission product nuclides as a group, because of their intimate link with energy production in fission reactors, occupy a unique position in the field of applied nuclear decay data. Further, in addition to their critical role in nuclear reactor technology (decay heat source term, environmental concerns, etc.), such data have important applications in astrophysical calculations involving the rapid neutron capture process (r-process) of elemental synthesis in stellar environments. The scope of the nuclear decay data measurements being undertaken using the Idaho National Engineering Laboratory's (INEL) isotope separation on-line (ISOL) facility is focused on a systematic study of the gross nuclear decay properties of short-lived fission product isotopes, i.e., ground-state half-lives, beta-decay energies and beta-decay feeding (or beta-strength) distributions. In this paper, the authors discuss the results of new measurements of beta-decay energies and feeding distributions

  3. $\\beta$3$p$-spectroscopy and proton-$\\gamma$ width determination in the decay of $^{31}$Ar

    CERN Multimedia

    We propose to perform a detailed study of the $\\beta$-decay of the dripline nucleus $^{31}$Ar. This will allow a detailed study of the $\\beta$-delayed 3$p$-decay as well as provide important information on the resonances of $^{30}$S and $^{29}$P, in particular the ratio between the $p$- and $\\gamma$- partial widths relevant for astrophysics.

  4. Computer code for double beta decay QRPA based calculations

    Energy Technology Data Exchange (ETDEWEB)

    Barbero, C. A.; Mariano, A. [Departamento de Física, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, La Plata, Argentina and Instituto de Física La Plata, CONICET, La Plata (Argentina); Krmpotić, F. [Instituto de Física La Plata, CONICET, La Plata, Argentina and Instituto de Física Teórica, Universidade Estadual Paulista, São Paulo (Brazil); Samana, A. R.; Ferreira, V. dos Santos [Departamento de Ciências Exatas e Tecnológicas, Universidade Estadual de Santa Cruz, BA (Brazil); Bertulani, C. A. [Department of Physics, Texas A and M University-Commerce, Commerce, TX (United States)

    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.

  5. New Limit on Time-Reversal Violation in Beta Decay

    International Nuclear Information System (INIS)

    Mumm, H. P.; Chupp, T. E.; Cooper, R. L.; Coulter, K. P.; Freedman, S. J.; Fujikawa, B. K.; Garcia, A.; Jones, G. L.; Nico, J. S.; Thompson, A. K.; Trull, C. A.; Wietfeldt, F. E.; Wilkerson, J. F.

    2011-01-01

    We report the results of an improved determination of the triple correlation DP·(p e xp v ) that can be used to limit possible time-reversal invariance in the beta decay of polarized neutrons and constrain extensions to the standard model. Our result is D=[-0.96±1.89(stat)±1.01(sys)]x10 -4 . The corresponding phase between g A and g V is φ AV =180.013 deg. ±0.028 deg. (68% confidence level). This result represents the most sensitive measurement of D in nuclear β decay.

  6. $^{11}$Be($\\beta$p), a quasi-free neutron decay?

    CERN Document Server

    Riisager, K.; Borge, M.J.G.; Briz, J.A.; Carmona-Gallardo, M.; Fraile, L.M.; Fynbo, H.O.U.; Giles, T.; Gottberg, A.; Heinz, A.; Johansen, J.G.; Jonson, B.; Kurcewicz, J.; Lund, M.V.; Nilsson, T.; Nyman, G.; Rapisarda, E.; Steier, P.; Tengblad, O.; Thies, R.; Winkler, S.R.

    2014-01-01

    We have observed $\\beta$-delayed proton emission from the neutron-rich nucleus $^{11}$Be by analysing a sample collected at the ISOLDE facility at CERN with accelerator mass spectrometry (AMS). With a branching ratio of (8.4 $\\pm$ 0.6)$\\times$ 10$^{-6}$ the strength of this decay mode, as measured by the B$_\\mathrm{GT}$-value, is unexpectedly high. The result is discussed within a simple single-particle model and could be interpreted as a quasi-free decay of the $^{11}$Be halo neutron into a single-proton state.

  7. Measurement of the 2{nu}{beta}{beta} decay of {sup 100}Mo to the excited 0{sub 1}{sup +} state in the NEMO3 experiment

    Energy Technology Data Exchange (ETDEWEB)

    Vala, L

    2003-09-01

    The NEMO3 detector was designed for the study of double beta decay and in particular to search for the neutrinoless double beta decay process (0{nu}{beta}{beta}). The intended sensitivity in terms of a half-life limit for the 0{nu}{beta}{beta} decay is of the order of 10{sup 25} y which corresponds to an effective neutrino mass m{sub {nu}} on the level of (0.3 - 0.1) eV. The 0{nu}{beta}{beta} process is today the most promising test of the Majorana nature of the neutrino. The detector was constructed in the Modane Underground Laboratory (LSM) in France by an international collaboration including France, Russia, the Czech Republic, the USA, the UK, Finland, and Japan. The experiment has been taking data since May 2002. The quantity of {sup 100}Mo in the detector (7 kg) allows an efficient measurement of the two-neutrino double beta decay (2{nu}{beta}{beta}) of {sup 100}Mo to the excited 0{sub 1}{sup +} state (eeN{gamma} channel). Monte-Carlo simulations of the effect and of all the relative sources of background have been produced in order to define a set of appropriate selection criteria. Both Monte-Carlo simulations and special runs with sources of {sup 208}Tl and {sup 214}Bi showed that the only significant background in the eeN{gamma} channel comes from radon that penetrated inside the wire chamber of NEMO3. The experimental data acquired from May 2002 to May 2003 have been analysed in order to determine the signal from the 2{nu}{beta}{beta} decay of {sup 100}Mo to the excited 0{sub 1}{sup +} state and the corresponding background level. The physical result, which was obtained at the level of four standard deviations, is given in the form of an interval of half-life values at 95% confidence level: [5.84*10{sup 20}, 2.26*10{sup 21}] y for method A and [5.83*10{sup 20}, 1.71*10{sup 21}] y for method B. (author)

  8. Double beta decay searches of 134Xe, 126Xe and 124Xe with large scale Xe detectors

    International Nuclear Information System (INIS)

    Barros, N; Thurn, J; Zuber, K

    2014-01-01

    The sensitivity for double beta decay studies of 134 Xe and 124 Xe is investigated assuming a potential large scale Xe experiment developed for dark matter searches depleted in 136 Xe. The opportunity for an observation of the 2νββ - decay of 134 Xe is explored for various scenarios. A positive observation should be possible for all calculated nuclear matrix elements. The detection of 2ν ECEC of 124 Xe can be probed in all scenarios covering the theoretical predicted half-life uncertainties and a potential search for 126 Xe is discussed. The sensitivity to β + EC decay of 124 Xe is discussed and a positive observation might be possible, while β + β + decay still remains unobservable. The performed studies take into account solar pp–neutrino interactions, 85 Kr beta decay and remaining 136 Xe double beta decay as background components in the depleted detector. (paper)

  9. Double Beta Decay

    International Nuclear Information System (INIS)

    Fiorini, Ettore

    2008-01-01

    The importance of neutrinoless Double Beta Decay (DBD) is stressed in view of the recent results of experiments on neutrino oscillations which indicate that the difference between the squared masses of two neutrinos of different flavours is finite [For a recent review including neutrino properties and recent results see: Review of Particle Physics, J. of Phys. G: Nuclear and Particle Physics 33, 1]. As a consequence the mass of at least one neutrino has to be different from zero and it becomes imperative to determine its absolute value. The various experimental techniques to search for DBD are discussed together with the difficult problems of the evaluation of the corresponding nuclear matrix elements. The upper limits on neutrino mass coming from the results of the various experiments are reported together with the indication for a non zero value by one of them not confirmed so far. The two presently running experiments on neutrinoless DBD are briefly described together with the already approved or designed second generation searches aiming to reach the values on the absolute neutrino mass indicated by the results on neutrino oscillations

  10. Search for neutrinoless double beta decay in {sup 136}Xe with EXO-200

    Energy Technology Data Exchange (ETDEWEB)

    Feldmeier, Wolfhart

    2015-02-19

    Several properties of neutrinos, such as their absolute mass, their possible Majorana nature or the mechanisms that lead to small neutrino masses, are still unknown. The EXO-200 experiment is trying to answer some of these questions by searching for the hypothetical neutrinoless double beta decay of the isotope {sup 136}Xe. This thesis describes an analysis of two years of detector data, which yields a lower limit on the half-life of neutrinoless double beta decay of {sup 136}Xe of 1.1 x 10{sup 25} years.

  11. Development of {sup 100}Mo-containing scintillating bolometers for a high-sensitivity neutrinoless double-beta decay search

    Energy Technology Data Exchange (ETDEWEB)

    Armengaud, E.; Gros, M.; Herve, S.; Magnier, P.; Navick, X.F.; Nones, C.; Paul, B.; Penichot, Y.; Zolotarova, A.S. [Universite Paris-Saclay, IRFU, CEA, Gif-sur-Yvette (France); Augier, C.; Billard, J.; Cazes, A.; Charlieux, F.; Jesus, M. de; Gascon, J.; Juillard, A.; Queguiner, E.; Sanglard, V.; Vagneron, L. [Univ Lyon, Universite Lyon 1, CNRS/IN2P3, IPN-Lyon, Villeurbanne (France); Barabash, A.S.; Konovalov, S.I.; Umatov, V.I. [National Research Centre Kurchatov Institute, Institute of Theoretical and Experimental Physics, Moscow (Russian Federation); Beeman, J.W. [Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Bekker, T.B. [V.S. Sobolev Institute of Geology and Mineralogy of the Siberian Branch of the RAS, Novosibirsk (Russian Federation); Bellini, F.; Ferroni, F. [Sapienza Universita di Roma, Dipartimento di Fisica, Rome (Italy); INFN, Sezione di Roma, Rome (Italy); Benoit, A.; Camus, P. [CNRS-Neel, Grenoble (France); Berge, L.; Chapellier, M.; Dumoulin, L.; Humbert, V.; Le Sueur, H.; Marcillac, P. de; Marnieros, S.; Marrache-Kikuchi, C.; Novati, V.; Olivieri, E.; Plantevin, O. [CSNSM, Univ. Paris-Sud, CNRS/IN2P3, Universite Paris-Saclay, Orsay (France); Bergmann, T.; Kleifges, M.; Tcherniakhovski, D.; Weber, M. [Karlsruhe Institute of Technology, Institut fuer Prozessdatenverarbeitung und Elektronik, Karlsruhe (Germany); Boiko, R.S.; Danevich, F.A.; Kobychev, V.V.; Nikolaichuk, M.O.; Tretyak, V.I. [Institute for Nuclear Research, Kyiv (Ukraine); Broniatowski, A. [CSNSM, Univ. Paris-Sud, CNRS/IN2P3, Universite Paris-Saclay, Orsay (France); Karlsruhe Institute of Technology, Institut fuer Experimentelle Teilchenphysik, Karlsruhe (Germany); Brudanin, V.; Rozov, S.; Yakushev, E. [JINR, Laboratory of Nuclear Problems, Dubna, Moscow Region (Russian Federation); Capelli, S.; Gironi, L.; Pavan, M.; Pessina, G. [Universita di Milano Bicocca, Dipartimento di Fisica, Milan (Italy); INFN, Sezione di Milano Bicocca, Milan (Italy); Cardani, L.; Casali, N.; Dafinei, I.; Tomei, C.; Vignati, M. [INFN, Sezione di Roma, Rome (Italy); Chernyak, D.M. [Institute for Nuclear Research, Kyiv (Ukraine); The University of Tokyo, Kavli Institute for the Physics and Mathematics of the Universe (WPI), The University of Tokyo Institutes for Advanced Study, Kashiwa, Chiba (Japan); Combarieu, M. de; Pari, P. [Universite Paris-Saclay, IRAMIS, CEA, Gif-sur-Yvette (France); Coron, N.; Redon, T. [Universite Paris-Sud, IAS, CNRS, Orsay (France); Devoyon, L.; Koskas, F.; Strazzer, O. [Universite Paris-Saclay, Orphee, CEA, Gif-sur-Yvette (France); Di Domizio, S. [Universita di Genova, Dipartimento di Fisica, Genoa (Italy); INFN Sezione di Genova, Genoa (Italy); Eitel, K.; Siebenborn, B. [Karlsruhe Institute of Technology, Institut fuer Kernphysik, Karlsruhe (Germany); Enss, C.; Fleischmann, A.; Gastaldo, L. [Heidelberg University, Kirchhoff Institute for Physics, Heidelberg (Germany); Foerster, N.; Kozlov, V. [Karlsruhe Institute of Technology, Institut fuer Experimentelle Teilchenphysik, Karlsruhe (Germany); Giuliani, A. [CSNSM, Univ. Paris-Sud, CNRS/IN2P3, Universite Paris-Saclay, Orsay (France); Universita dell' Insubria, DISAT, Como (Italy); Grigorieva, V.D.; Ivannikova, N.V.; Ivanov, I.M.; Makarov, E.P.; Shlegel, V.N.; Vasiliev, Ya.V. [Nikolaev Institute of Inorganic Chemistry, Novosibirsk (Russian Federation); Hehn, L. [Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Karlsruhe Institute of Technology, Institut fuer Kernphysik, Karlsruhe (Germany); Jin, Y. [Laboratoire de Photonique et de Nanostructures, CNRS, Marcoussis (France); Kraus, H. [University of Oxford, Department of Physics, Oxford (United Kingdom); Kudryavtsev, V.A. [University of Sheffield, Department of Physics and Astronomy, Sheffield (United Kingdom); Laubenstein, M.; Nagorny, S.; Pattavina, L.; Pirro, S. [INFN, Laboratori Nazionali del Gran Sasso, Assergi, AQ (Italy); Loidl, M.; Rodrigues, M. [CEA-Saclay, CEA, LIST, Laboratoire National Henri Becquerel (LNE-LNHB), Gif-sur-Yvette Cedex (France); Mancuso, M. [CSNSM, Univ. Paris-Sud, CNRS/IN2P3, Universite Paris-Saclay, Orsay (France); Universita dell' Insubria, DISAT, Como (Italy); Max-Planck-Institut fuer Physik, Munich (Germany); Pagnanini, L.; Schaeffner, K. [INFN, Laboratori Nazionali del Gran Sasso, Assergi, AQ (Italy); INFN, Gran Sasso Science Institute, L' Aquila (Italy); Piperno, G. [INFN, Laboratori Nazionali di Frascati, Rome (Italy); Poda, D.V. [CSNSM, Univ. Paris-Sud, CNRS/IN2P3, Universite Paris-Saclay, Orsay (France); Institute for Nuclear Research, Kyiv (Ukraine); Rusconi, C. [INFN, Laboratori Nazionali del Gran Sasso, Assergi, AQ (Italy); University of South Carolina, Department of Physics and Astronomy, Columbia, SC (United States); Scorza, S. [Karlsruhe Institute of Technology, Institut fuer Experimentelle Teilchenphysik, Karlsruhe (Germany); SNOLAB, Lively, ON (Canada); Velazquez, M. [Universite de Bordeaux, ICMCB, CNRS, Pessac (France)

    2017-11-15

    This paper reports on the development of a technology involving {sup 100}Mo-enriched scintillating bolometers, compatible with the goals of CUPID, a proposed next-generation bolometric experiment to search for neutrinoless double-beta decay. Large mass (∝ 1 kg), high optical quality, radiopure {sup 100}Mo-containing zinc and lithium molybdate crystals have been produced and used to develop high performance single detector modules based on 0.2-0.4 kg scintillating bolometers. In particular, the energy resolution of the lithium molybdate detectors near the Q-value of the double-beta transition of {sup 100}Mo (3034 keV) is 4-6 keV FWHM. The rejection of the α-induced dominant background above 2.6 MeV is better than 8σ. Less than 10 μBq/kg activity of {sup 232}Th({sup 228}Th) and {sup 226}Ra in the crystals is ensured by boule recrystallization. The potential of {sup 100}Mo-enriched scintillating bolometers to perform high sensitivity double-beta decay searches has been demonstrated with only 10 kg x d exposure: the two neutrino double-beta decay half-life of {sup 100}Mo has been measured with the up-to-date highest accuracy as T{sub 1/2} = [6.90 ± 0.15(stat.) ± 0.37(syst.)] x 10{sup 18} years. Both crystallization and detector technologies favor lithium molybdate, which has been selected for the ongoing construction of the CUPID-0/Mo demonstrator, containing several kg of {sup 100}Mo. (orig.)

  12. Kinematic shifts of beta -delayed particles as a probe of beta - nu angular correlations

    CERN Document Server

    Clifford, E T H; Evans, H C; Fästermann, T; Hagberg, E; Hardy, J C; Jackson, K P; Koslowsky, V T; Schmeing, H; Schrewe, U J

    1981-01-01

    Beta-delayed particles undergo a kinematic shift in energy due to recoil motion of the daughter nucleus following beta decay. A careful measurement of this energy shift can be used to establish the ratio of vector to axial vector components in beta transitions. Alpha-beta coincidence data for the beta-delayed alpha decay of /sup 20/Na have been obtained. Component ratios for 6 transitions including the superallowed branch are found. Limits on charge dependent mixing with the analogue state are deduced for 5 states in /sup 20/Ne*. For the superallowed branch the axial vector component is found; the polar vector component is deduced and establishes a value for the vector weak coupling constant of G/sub V/=(1.355+or-0.036)*10/sup -49/ erg cm /sup 3/. (13 refs).

  13. BETA SPECTRA. I. Negatrons spectra; ESPECTROS BETA. I. Espectros simples de negatrones

    Energy Technology Data Exchange (ETDEWEB)

    Grau Malonda, A; Garcia-Torano, E

    1978-07-01

    Using the Fermi theory of beta decay, the beta spectra for 62 negatrons emitters have been computed introducing a correction factor for unique forbidden transitions. These spectra are plotted vs. energy, once normal i sed, and tabulated with the related Fermi functions. The average and median energies are calculated. (Author)

  14. Search for 136Xe neutrinoless double beta decay with the Enriched Xenon Observatory (EXO)

    International Nuclear Information System (INIS)

    Giroux, G.

    2014-01-01

    The EXO collaboration is searching for the neutrinoless double beta decay of 136 Xe. Such observation would determine an absolute mass scale for the neutrinos, establish their Majorana nature, and uncover physics beyond the Standard Model. The EXO-200 detector is a single phase liquid xenon ultra low background TPC (Time Projection Chamber), with an active mass of 110 kg of 80.6% enriched xenon in the isotope 136. The detector is currently operating at the WIPP site and has been collecting data with enriched xenon since May 2011. The data collected give a lower limit for the neutrinoless double beta decay half-life of 136 Xe: T > 1.6*10 25 years at 90% C.L. The same data give a lower limit for the 2 neutrinos double beta decay of 136 Xe: T > 2.23*10 21 years that agrees with experimental values found in the literature

  15. Determination of the Electron Neutrino Mass from Experiments on Electron-Capture Beta-Decay (EC)

    CERN Multimedia

    2002-01-01

    The aim of the programme is to measure the electron-neutrino mass, for which at present an upper limit of 500~eV is known. \\\\ \\\\ The experiment studies the shape of the internal bremsstrahlung spectrum in electron-capture near its upper end-point and deduces a mass from small shape changes completely analogous to those in the well-known determination of the electron antineutrino mass in the tritium beta-minus decay. \\\\ \\\\ In a low-energy bremsstrahlung process, the capture takes place from a virtual S state associated with a radiative P~@A~S electromagnetic transition, and the resonant nature of the process leads to important enhancements of the photon intensities at low energy, in particular near the resonance energies co (X-rays). This effect gives this type of experiment a chance to compete with experiments on continuous beta spectra. \\\\ \\\\ The programme concentrates on two long-lived isotopes: \\\\ \\\\ 1)~~|1|6|3Ho. The Q value for this isotope has been found to be 2.6-2.7 keV. A detector specially construct...

  16. First Accurate Normalization of the $\\beta$-delayed $\\alpha$ Decay of $^{16}$N and Implications for the $^{12}$C$(\\alpha,\\gamma)^{16}$O Astrophysical Reaction Rate arXiv

    CERN Document Server

    Kirsebom, O.S.; Lica, R.; Munch, M.; Riisager, K.; Fynbo, H.O.U.; Borge, M.J.G.; Madurga, M.; Marroquin, I.; Andreyev, A.N.; Berry, T.A.; Christensen, E.R.; Fernández, P. Díaz; Doherty, D.T.; Van Duppen, P.; Fraile, L.M.; Gallardo, M.C.; Greenlees, P.T.; Harkness-Brennan, L.J.; Hubbard, N.; Huyse, M.; Jensen, J.H.; Johansson, H.; Jonson, B.; Judson, D.S.; Konki, J.; Lazarus, I.; Lund, M.V.; Marginean, N.; Marginean, R.; Perea, A.; Mihai, C.; Negret, A.; Page, R.D.; Pucknell, V.; Rahkila, P.; Sorlin, O.; Sotty, C.; Swartz, J.A.; Sørensen, H.B.; Törnqvist, H.; Vedia, V.; Warr, N.; De Witte, H.

    The $^{12}$C$(\\alpha,\\gamma)^{16}$O reaction plays a central role in astrophysics, but its cross section at energies relevant for astrophysical applications is only poorly constrained by laboratory data. The reduced $\\alpha$ width, $\\gamma_{11}$, of the bound $1^-$ level in $^{16}$O is particularly important to determine the cross section. The magnitude of $\\gamma_{11}$ is determined via sub-Coulomb $\\alpha$-transfer reactions or the $\\beta$-delayed $\\alpha$ decay of $^{16}$N, but the latter approach is presently hampered by the lack of sufficiently precise data on the $\\beta$-decay branching ratios. Here we report improved branching ratios for the bound $1^-$ level and for $\\beta$-delayed $\\alpha$ emission. In the case of the $\\beta$-delayed $\\alpha$ branch, we find a $5\\sigma$ deviation from the literature value. With our new branching ratios, the constraints imposed on $\\gamma_{11}$ by the $\\beta\\alpha$-decay and $\\alpha$-transfer data are of similar precision and, for the first time, in good agreement. Th...

  17. Proposed experimental test of Bell's inequality in nuclear beta decay

    International Nuclear Information System (INIS)

    Skalsey, M.

    1986-01-01

    A β decay experiment is proposed for testing Bell's inequality, related to hidden-variables alternatives to quantum mechanics. The experiment uses Mott scattering for spin polarization analysis of internal conversion electrons. Beta-decay electrons, in cascade with the conversion electrons, are longitudinally polarized due to parity violation in the weak interaction. So simply detecting the β electron direction effectively measures the spin. A two-particle spin-spin correlation can thus be investigated and related, within certain assumptions, to Bell's inequality. The example of 203 Hg decay is used for a calculation of expected results. Specific problems related to nuclear structure and experimental inconsistencies are also discussed

  18. The MAJORANA DEMONSTRATOR Neutrinoless Double-Beta Decay Experiment

    Directory of Open Access Journals (Sweden)

    N. Abgrall

    2014-01-01

    Full Text Available The Majorana Demonstrator will search for the neutrinoless double-beta (ββ0ν decay of the isotope Ge 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.

  19. The Majorana Double Beta Decay Experiment:. Present Status

    Science.gov (United States)

    Aguayo, E.; Avignone, F. T.; Back, H. O.; Barabash, A. S.; Beene, J. R.; Bergevin, M.; Bertrand, F. E.; Boswell, M.; Brudanin, V.; Busch, M.; Chan, Y.-D.; Christofferson, C. D.; Collar, J. I.; Combs, D. C.; Cooper, R. J.; Detwiler, J. A.; Doe, P. J.; Efremenko, Yu.; Egorov, V.; Ejiri, H.; Elliott, S. R.; Esterline, J.; Fast, J. E.; Fields, N.; Finnerty, P.; Fraenkle, F. M.; Gehman, V. M.; Giovanetti, G. K.; Green, M. P.; Guiseppe, V. E.; Gusey, K.; Hallin, A. L.; Hazama, R.; Henning, R.; Hime, A.; Hoppe, E. W.; Horton, M.; Howard, S.; Howe, M. A.; Johnson, R. A.; Keeter, K. J.; Keller, C.; Kidd, M. F.; Knecht, A.; Kochetov, O.; Konovalov, S. I.; Kouzes, R. T.; Laferriere, B. D.; Laroque, B. H.; Leon, J.; Leviner, L. E.; Loach, J. C.; Macmullin, S.; Marino, M. G.; Martin, R. D.; Mei, D.-M.; Merriman, J. H.; Miller, M. L.; Mizouni, L.; Nomachi, M.; Orrell, J. L.; Overman, N. R.; Phillips, D. G.; Poon, A. W. P.; Perumpilly, G.; Prior, G.; Radford, D. C.; Rielage, K.; Robertson, R. G. H.; Ronquest, M. C.; Schubert, A. G.; Shima, T.; Shirchenko, M.; Snavely, K. J.; Steele, D.; Strain, J.; Thomas, K.; Timkin, V.; Tornow, W.; Vanyushin, I.; Varner, R. L.; Vetter, K.; Vorren, K.; Wilkerson, J. F.; Yakushev, E.; Young, A. R.; Yu, C.-H.; Yumatov, V. I.; Zhang, C.

    2013-11-01

    The Majorana collaboration is actively pursuing research and development aimed at a tonne-scale 76Ge neutrinoless double-beta decay (0νββ) experiment. The current, primary focus is the construction of the Majorana Demonstrator 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.

  20. Exchange effects in double beta decay

    International Nuclear Information System (INIS)

    Stephenson, G.J. Jr.; Goldman, T.; Maltman, K.R.; Schmidt, K.E.

    1988-01-01

    The motivation underlying the resurgence of interest in double beta decay is the hope that the observation of or limits on the 0-neutrino mode will provide information about the nature of the neutrino. This clearly requires confidence in the nuclear matrix elements involved in the transition. The shell model calculations do not agree well with the geochemical values for 130 Te, which has lead to a spate of papers offering specific fixes for the problem. In this contribution we shall not comment on any of the specific nuclear calculations, rather we make some remarks which should be relevant to any model calculation

  1. Beta-decay of {sup 71}Co and {sup 73}Co

    Energy Technology Data Exchange (ETDEWEB)

    Sawicka, M.; Pfuetzner, M. [Warsaw University, IEP, Warsaw (Poland); Matea, I.; Lewitowicz, M.; France, G. de; Georgiev, G. [GANIL, B.P. 5027, Caen Cedex 5 (France); Grawe, H.; Becker, F. [Gesellschaft fuer Schwerionenforschung mbH, Darmstadt, Darmstadt (Germany); Grzywacz, R. [Warsaw University, IEP, Warsaw (Poland); ORNL, Physics Division, Oak Ridge, TN (United States); Daugas, J.M.; Belier, G. [CEA Bruyeres-le-Chatel DIF/DPTA/SPN, B.P. 12, Bruyeres-le-Chatel (France); Brown, B.A.; Lisetskiy, A. [Michigan State University, Department of Physics and Astronomy and NSCL, East Lansing, MI (United States); Bingham, C. [University of Tennesse, Department of Physics and Astronomy, Knoxville, TN (United States); Borcea, R.; Buta, A.; Dragulescu, E. [IFIN, P.O. Box MG6, Bucharest-Magurele (Romania); Bouchez, E. [DSM/DAPNIA/SPhN, CEA Saclay, Gif-sur-Yvette Cedex (France); Giovinazzo, J. [CENBG, B.P. 120, Gradignan Cedex (France); Hammache, F. [IPN, Orsay Cedex (France); Ibrahim, F.; Mayet, P.; Meot, V.; Negoita, F.; De Oliveira-Santos, F; Perru, O.; Roig, O.; Rykaczewski, K.; Saint-Laurent, M.G.; Sauvestre, J.E.; Sorlin, O.; Stanoiu, M.; Stefan, I.; Stodel, C.; Theisen, C.; Verney, D.; Zylicz, J.

    2004-12-01

    A decay spectroscopy study of the neutron-rich cobalt isotopes has been performed using fragmentation of a {sup 86}Kr{sup 36+} beam and the new LISE2000 spectrometer at GANIL. For {sup 71}Co and {sup 73}Co, the {beta}-delayed {gamma} radiation has been observed for the first time, and the half-lives were found to be 79(5) ms and 41(4) ms, respectively. Features of the decay are discussed qualitatively in terms of nuclear models. (orig.)

  2. Beta-decay of {sup 103}In: evidence for the Gamow-Teller resonance near {sup 100}Sn

    Energy Technology Data Exchange (ETDEWEB)

    Karny, M. [Warsaw Univ. (Poland). Inst. of Experimental Physics; Batist, L.; Brown, B.A. [and others

    1998-04-01

    The {beta} decay of the neutron-deficient isotope {sup 103}In was investigated by using total absorption {gamma}-ray spectrometry on mass-separated sources. The measurement reveals a high-lying resonance of the {beta}-decay strength in striking disagreement with high-resolution {gamma}-ray data. The result is discussed in comparison with shell-model predictions. (orig.)

  3. Measurement of Radon-Induced Backgrounds in the NEXT Double Beta Decay Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Novella, P.; et al.

    2018-04-02

    The measurement of the internal 222Rn activity in the NEXT-White detector during the so-called Run-II period with 136Xe-depleted xenon is discussed in detail, together with its implications for double beta decay searches in NEXT. The activity is measured through the alpha production rate induced in the fiducial volume by 222Rn and its alpha-emitting progeny. The specific activity is measured to be $(37.5\\pm 2.3~\\mathrm{(stat.)}\\pm 5.9~\\mathrm{(syst.)})$~mBq/m$^3$. Radon-induced electrons have also been characterized from the decay of the 214Bi daughter ions plating out on the cathode of the time projection chamber. From our studies, we conclude that radon-induced backgrounds are sufficiently low to enable a successful NEXT-100 physics program, as the projected rate contribution should not exceed 0.2~counts/yr in the neutrinoless double beta decay sample.

  4. Beta decay and muon capture rates in a self-consistent relativistic framework

    Energy Technology Data Exchange (ETDEWEB)

    Marketin, Tomislav; Paar, Nils; Niksic, Tamara; Vretenar, Dario [Physics Department, Faculty of Science, University of Zagreb (Croatia); Ring, Peter [Physik-Department, Technische Universitaet Muenchen, D-85748 Muenchen (Germany)

    2009-07-01

    A fully consistent calculation of muon capture and beta decay rates is presented, based on a microscopic theoretical framework describing the semileptonic weak interaction processes. Nuclear ground state is determined using the Relativistic Hartree-Bogolyubov (RHB) model with density dependent meson-nucleon coupling constants, and transition rates are calculated via proton-neutron relativistic quasiparticle RPA using the same interaction as in the RHB equations. Muon capture rates are calculated for a wide range of nuclei along the valley of stability, from {sup 12}C to {sup 244}Pu, with accuracy of approximately 30%, using the interaction DD-ME2. Previous studies of beta decay rates have only taken into account Gamow-Teller transitions. We extend this approach by including forbidden transitions and systematically study their contribution to decay rates of exotic nuclei along the r-process path, which are important for constraining the conditions in which nucleosynthesis takes place.

  5. Relation between the 2{nu}{beta}{beta} and 0{nu}{beta}{beta} nuclear matrix elements

    Energy Technology Data Exchange (ETDEWEB)

    Vogel, Petr [Kellogg Radiation Laboratory, Caltech, Pasadena, CA 91125 (United States); Simkovic, Fedor [Department of Nuclear Physics and Biophysics, Comenius University, Mlynska dolina F1, SK-84248 Bratislava (Slovakia)

    2011-12-16

    A formal relation between the GT part of the nuclear matrix elements M{sub GT}{sup 0{nu}} of 0{nu}{beta}{beta} decay and the closure matrix elements M{sub cl}{sup 2{nu}} of 2{nu}{beta}{beta} decay is established. This relation is based on the integral representation of these quantities in terms of their dependence on the distance r between the two nucleons undergoing transformation. We also discuss the difficulties in determining the correct values of the closure 2{nu}{beta}{beta} decay matrix elements.

  6. Search for neutrinoless double beta decay beyond GERDA

    Energy Technology Data Exchange (ETDEWEB)

    Schwingenheuer, Bernhard [MPI Kernphysik, Heidelberg (Germany)

    2016-07-01

    The search for neutrinoless double beta decay might be the only window to observe lepton number violation and to determine the nature of neutrinos. Is is therefore considered to be of highest relevance. The isotope Ge-76 has historically been most important for this search and the ongoing experiment GERDA has the lowest background of all experiments in the field. The proposed experimental program beyond GERDA (and Majorana) is presented.

  7. Gerda: A new 76Ge Double Beta Decay Experiment at Gran Sasso

    International Nuclear Information System (INIS)

    Simgen, Hardy

    2005-01-01

    In the new 76 Ge double beta decay experiment Gerda [I. Abt et al., arXiv hep-ex/0404039; Gerda proposal, to be submitted to the Gran Sasso scientific committee] bare diodes of enriched 76 Ge will be operated in highly pure liquid nitrogen or argon. The goal is to reduce the background around Q ββ =2039 keV below 10 -3 counts/(kg-bar keV-bar y). With presently available diodes from the Igex and HdMs experiments the current evidence for neutrinoless double beta decay [H.-V. Klapdor-Kleingrothaus, et al., Mod. Phys. Lett. A16 (2001) 2409ff] can unambigously be checked within one year of measurement

  8. Double beta decay of Uranium-238: Proton reactions of 238U in 5--12 MeV range. Final report, April 15, 1987--March 31, 1992

    International Nuclear Information System (INIS)

    Turkevich, A.; Economou, T.E.

    1993-01-01

    This report is in two parts. The first part reports on the experimental work determining the half-life for double beta decay of 238 U to 238 PU to be (2.0 ± 0.6) x 10 21 years. This is the first evidence for a third mode of decay of this heaviest naturally occurring nucleus. This rate is about 10 6 times slower than spontaneous fission, which itself is about 10 6 times slower than alpha decay. The implication of this double beta decay to neutrino masses depends on uncertain theoretical calculations of the rate for such a heavy nucleus. The second part reports on yields of principal fission products from 5.6, 7.3, 9.4, and 11.5 MeV proton interactions with 238 U. The yields at 11.5 MeV are similar to those from 14 MeV neutron fission of 238 U. At the same time, the production cross sections of 238 Np at the same energies are determined. This nuclide is produced as often as fission at the lowest energy but only 3.8% as often at the highest energy

  9. Energy distribution of antineutrinos originating from the decay of fission products in a nuclear reactor

    International Nuclear Information System (INIS)

    Rudstam, G.; Aleklett, K.

    1979-01-01

    The energy spectrum of antineutrinos around a nuclear reactor has been derived by summing contributions from individual fission products. The resulting spectrum is weaker at energies above approx. 8 MeV than earlier published antineutrino spectra. The reason may be connected to the strong feeding of high-lying daughter states in the beta decay of fission products with high disintegration energies

  10. Energy distribution of the 'shake off' electrons at the 152Eu decay

    International Nuclear Information System (INIS)

    Mitrokhovich, N.F.

    2008-01-01

    On the special vacuum installation of coincidences of g-quanta and beta-particles with low energy electrons, including e 0 -electrons of the secondary electron emission (gamma beta e 0 -coincidences) for the first time the energy spectrum of 'shake off' electrons at 152 Eu decay is investigated in the range of 200 - 1700 eV. Registration of electrons of 'shake off' is carried out on e 0 -electrons of the secondary electron emission, created by them. By realization of threshold measurements the integral spectrum was obtained and on this basis the differential spectrum is computed. It is established, that the continuum of 'shake off' electrons is low energy and practically finishes at 400 eV. In the region of 300 eV the maximum energetic distribution is observed

  11. Nuclear spectroscopic investigations of the decay of /sup 155/Eu

    Energy Technology Data Exchange (ETDEWEB)

    Patt, B H

    1974-01-01

    The investigations carried out on the ..beta..-decay of /sup 155/Eu confirm some decay data of this nucleus and explain a few disagreements on the decay scheme. Using the half-life, the ..beta..-boundary energies and branching ratios, the log ft values of the individual ..beta..-transitions were calculated. Finally, by means of ..beta gamma..-coincidence measurements on the semiconductor spectrometer, the inner partial spectra ..beta../sub 3/ and ..beta../sub 4/ were separated for the first time. Form factor investigations were carried out on these spectra which, despite the high log ft values, confirm the allowed character of these transitions.

  12. Cosmology with decaying particles

    Energy Technology Data Exchange (ETDEWEB)

    Turner, M.S.

    1984-09-01

    We consider a cosmological model in which an unstable massive relic particle species (denoted by X) has an initial mass density relative to baryons ..beta../sup -1/ identically equal rho/sub X//rho/sub B/ >> 1, and then decays recently (redshift z less than or equal to 1000) into particles which are still relativistic today (denoted by R). We write down and solve the coupled equations for the cosmic scale factor a(t), the energy density in the various components (rho/sub X/, rho/sub R/, rho/sub B/), and the growth of linear density perturbations (delta rho/rho). The solutions form a one parameter (..beta..) family of solutions; physically ..beta../sup -1/ approx. = (..cap omega../sub R//..cap omega../sub NR/) x (1 + z/sub D/) = (ratio today of energy density of relativistic to nonrelativistic particles) x (1 + redshift of (decay)). We discuss the observational implications of such a cosmological model and compare our results to earlier results computed in the simultaneous decay approximation. In an appendix we briefly consider the case where one of the decay products of the X is massive and becomes nonrelativistic by the present epoch. 21 references.

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

    Energy Technology Data Exchange (ETDEWEB)

    Kogler, Laura K. [Univ. of California, Berkeley, CA (United States)

    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. Inner bremsstrahlung accompanying beta decay of 170Tm

    International Nuclear Information System (INIS)

    Sanjeeviah, H.; Venkataramaiah, P.; Gundu Rao, K.S.

    1980-01-01

    The inner bremmsstrahlung (IB) spectrum accompanying beta decay of 170 Tm was measured using magnetic deflection technique. The raw spectrum was unfolded using the procedure of Liden and Starfelt. The unfolded IB spectrum was compared with the theories of Knipp and Uhlenbeck and Bloch; Lewis and Ford. Comparison was made with Ford and Martin theory in order to estimate the contribution of detour transitions to the IB spectrum of 170 Tm. (author)

  15. Results on neutrinoless double beta decay from GERDA phase I

    CERN Multimedia

    CERN. Geneva

    2013-01-01

    After motivating searches of double beta decay and lepton number violation details about the construction, operation and analysis of GERDA will be given. Results of the recently completed phase I of data taking will then be presented and interpreted. Finally an outlook on future plans will be given.

  16. $\\beta$ decay of $^{47}$Ar

    CERN Document Server

    Weissman, L; Bergmann, U C; Brown, B A; Catherall, R; Cederkäll, J; Dillmann, I; Hallmann, O; Fraile-Prieto, L M; Franchoo, S; Gaudefroy, L; Köster, U; Kratz, K L; Pfeiffer, B; Sorlin, O; 10.1103/PhysRevC.70.024304

    2004-01-01

    Information on beta -decay properties of neutron-rich /sup 47/Ar was obtained at the ISOLDE facility at CERN using isobaric selectivity. This was achieved by a combination of a plasma-ion source with a cooled transfer line and subsequent mass separation. A doubly charged beam was used in order to improve the signal-to-background ratio associated with multi-charged noble gas fission products. The identification of the /sup 47/Ar gamma -ray transitions was performed by comparing the spectra obtained from direct proton bombardment of the target and of the neutron converter. New excited levels in the daughter /sup 47/K nucleus corresponding to the negative-parity states were observed. The obtained data are compared to the result of large-scale shell model calculations and quasiparticle random-phase approximation predictions. (29 refs).

  17. NEUTRINOLESS DOUBLE BETA DECAY: AN EXTREME CHALLENGE

    Directory of Open Access Journals (Sweden)

    Fernando Ferroni

    2013-12-01

    Full Text Available Neutrino-less Double Beta Decay is the only known way to possibly resolve the nature of neutrino mass. The chances to cover the mass region predicted by the inverted hierarchy require a step forward in detector capability. A possibility is to make use of scintillating bolometers. These devices shall have a great power in distinguishing signals from alfa particles from those induced by electrons. This feature might lead to an almost background-free experiment. Here the Lucifer concept will be introduced and the prospects related to this project will be discussed.

  18. Beta spectra. II-Positron spectra

    International Nuclear Information System (INIS)

    Grau, A.; Garcia-Torano, E.

    1981-01-01

    Using the Fermi theory of beta decay, the beta spectra for 30 positron emitters have been computed, introducing a correction factor for unique forbidden transitions. The spectra are ploted vs. energy, once normalised, and tabulated with the related Fermi functions. The average and median energies are calculated. (author)

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

    Science.gov (United States)

    Finnerty, P.; Aguayo, E.; Amman, M.; Avignone, F. T., Iii; Barabash, A. S.; Barton, P. J.; Beene, J. R.; Bertrand, F. E.; Boswell, M.; Brudanin, V.; Busch, M.; Chan, Y.-D.; Christofferson, C. D.; Collar, J. I.; Combs, D. C.; Cooper, R. J.; Detwiler, J. A.; Doe, P. J.; Efremenko, Yu; Egorov, V.; Ejiri, H.; Elliott, S. R.; Esterline, J.; Fast, J. E.; Fields, N.; Fraenkle, F. M.; Galindo-Uribarri, A.; Gehman, V. M.; Giovanetti, G. K.; Green, M. P.; Guiseppe, V. E.; Gusey, K.; Hallin, A. L.; Hazama, R.; Henning, R.; Hoppe, E. W.; Horton, M.; Howard, S.; Howe, M. A.; Johnson, R. A.; Keeter, K. J.; Kidd, M. F.; Knecht, A.; Kochetov, O.; Konovalov, S. I.; Kouzes, R. T.; LaFerriere, B. D.; Leon, J.; Leviner, L. E.; Loach, J. C.; Luke, P. N.; MacMullin, S.; Marino, M. G.; Martin, R. D.; Merriman, J. H.; Miller, M. L.; Mizouni, L.; Nomachi, M.; Orrell, J. L.; Overman, N. R.; Perumpilly, G.; Phillips, D. G., Ii; Poon, A. W. P.; Radford, D. C.; Rielage, K.; Robertson, R. G. H.; Ronquest, M. C.; Schubert, A. G.; Shima, T.; Shirchenko, M.; Snavely, K. J.; Steele, D.; Strain, J.; Timkin, V.; Tornow, W.; Varner, R. L.; Vetter, K.; Vorren, K.; Wilkerson, J. F.; Yakushev, E.; Yaver, H.; Young, A. R.; Yu, C.-H.; Yumatov, V.; Majorana Collaboration

    2014-03-01

    The Majorana Demonstrator will search for the neutrinoless double-beta decay (0vββ) 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 low-background environment and surrounded by passive and active shielding. The goals for the Demonstrator are: demonstrating a background rate less than 3 t-1 y-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 0vββ [1]; and performing a direct search for light WIMPs (3-10 GeV/c2).

  20. Nuclear beta decay induced by intense electromagnetic fields: Forbidden transition examples

    International Nuclear Information System (INIS)

    Reiss, H.R.

    1983-01-01

    A formalism developed earlier for the effect on nuclear beta decay of an intense plane-wave electromagnetic field is applied to three examples of forbidden beta transitions. The examples represent cases where the nuclear ''fragment'' contains one, two, and three nucleons; where the nuclear fragment is defined to be that smallest sub-unit of the nucleus containing the nucleon which undergoes beta decay plus any other nucleons directly angular-momentum coupled to it in initial or final states. The single-nucleon-fragment example is 113 Cd, which has a fourth-forbidden transition. The two-nucleon-fragment example is 90 Sr, which is first-forbidden. The three-nucleon-fragment example is 87 Rb, which is third-forbidden. An algebraic closed-form transition probability is found in each case. At low external-field intensity, the transition probability is proportional to z/sup L/, where z is the field intensity parameter and L is the degree of forbiddenness. At intermediate intensities, the transition probability behaves as z/sup L/-(1/2). At higher intensities, the transition probability contains the z/sup L/-(1/2) factor, a declining exponential factor, and an alternating polynomial in z. This high-intensity transition probability possesses a maximum value, which is found for each of the examples. A general rule, z = q 2 (2L-1), where q is the number of particles in the fragment, is found for giving an upper limit on the intensity at which the maximum transition probability occurs. Field-induced beta decay half-lives for all the examples are dramatically reduced from natural half-lives when evaluated at the optimum field intensity. Relative half-life reduction is greater the higher the degree of forbiddenness

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  2. $\\beta$- decay of $^{58}$Zn. A critical test for the charge-exchange reaction as a probe for the $\\beta$- decay strength distribution

    CERN Multimedia

    2002-01-01

    % IS353 \\\\ \\\\ Due to its importance in fundamental physics and astrophysics, a great effort both theoretically and experimentally is devoted to study Gamow Teller (GT)-strength. The GT-strength and its distribution play a key role in late stellar evolution. During the pre-supernova core-collapse of massive stars, the electron capture and nuclear $\\beta$ -decay determine the electron-to-baryon ratio, which influences the infall dynamics and the mass of the final core. The cross-section of the charge-exchange reaction at forward angles with energies above 100~MeV is expected to be proportional to the squares of Fermi and GT matrix elements. This proportionality should provide a Q-value free method to probe the weak interaction strength and renormalization effects in nuclei. Thus charge-exchange reactions are often used to determine the experimental GT-strength. However, the connection between the GT-strength and the cross-section of the charge-exchange reaction is partially model-dependent and the question aris...

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

    International Nuclear Information System (INIS)

    Fairbank, William

    2016-01-01

    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 "1"3"6Xe, 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 1.9x10"2"5 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"+ ions in gaseous xenon. Through

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

    Energy Technology Data Exchange (ETDEWEB)

    Fairbank, William [Colorado State Univ., Fort Collins, CO (United States)

    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

  5. A semiconductor beta ray spectrometer

    International Nuclear Information System (INIS)

    Bom, V.R.

    1987-01-01

    Measurement of energy spectra of beta particles emitted from nuclei in beta-decay processes provides information concerning the mass difference of these nuclei between initial and final state. Moreover, experimental beta spectra yield information on the feeding of the levels in the daughter nucleus. Such data are valuable in the construction and checking of the level schemes. This thesis describes the design, construction, testing and usage of a detector for the accurate measurement of the mentioned spectra. In ch. 2 the design and construction of the beta spectrometer, which uses a hyper-pure germanium crystal for energy determination, is described. A simple wire chamber is used to discriminate beta particles from gamma radiation. Disadvantages arise from the large amounts of scattered beta particles deforming the continua. A method is described to minimize the scattering. In ch. 3 some theoretical aspects of data analysis are described and the results of Monte-Carlo simulations of the summation of annihilation radiation are compared with experiments. Ch. 4 comprises the results of the measurements of the beta decay energies of 103-108 In. 87 refs.; 34 figs.; 7 tabs

  6. BETA SPECTRA. I. Negatrons spectra

    International Nuclear Information System (INIS)

    Grau Malonda, A.; Garcia-Torano, E.

    1978-01-01

    Using the Fermi theory of beta decay, the beta spectra for 62 negatrons emitters have been computed introducing a correction factor for unique forbidden transitions. These spectra are plotted vs. energy, once normal i sed, and tabulated with the related Fermi functions. The average and median energies are calculated. (Author)

  7. Beta and gamma decay heat evaluation for the thermal fission of 235U

    International Nuclear Information System (INIS)

    Schenter, G.K.; Schmittroth, F.

    1979-01-01

    Beta and gamma fission product decay heat curves are evaluated for the thermal fission of 235 U. Experimental data that include beta, gamma, and total measurements are combined with summation calculations based on ENDF/B in a consistent evaluation. Least-squares methods are used that take proper account of data uncertainties and correlations. 4 figures, 2 tables

  8. Neutrinoless double beta decay in GERDA Phase II

    International Nuclear Information System (INIS)

    Macolino, C.

    2014-01-01

    The GERmanium Detector Array, GERDA, is designed to search for neutrinoless double beta (0νββ) decay of 76 Ge and it is installed in the Laboratori Nazionali del Gran Sasso (LNGS) of INFN, Italy. The GERDA experiment has completed the Phase I with a total collected exposure of 21.6 kg yr and a background index (BI) of the order of BI ≃ 10 −2 cts/(keVkg yr). No excess of events from 0νββ decay has been observed and a lower limit on the half-life on the 0νββ decay for 76 Ge has been estimated: T 0ν 1 /2 > 2.1·10 25 yr at 90% CL. The goal of GERDA Phase II is to reach the target sensitivity of T 0ν 1 /2 ≃ 1.4 · 10 26 yr, with an increased total mass of the enriched material and a reduced background level. In this paper the results from GERDA Phase I and the major improvements planned for Phase II are discussed.

  9. Few active mechanisms of the neutrinoless double beta-decay and effective mass of Majorana neutrinos

    CERN Document Server

    Simkovic, Fedor; Faessler, Amand

    2010-01-01

    It is well known that there exist many mechanisms that may contribute to neutrinoless double beta decay (0nbb-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, assuming the observation of the 0nbb-decay in three different nuclei, e.g., 76Ge, 100Mo and 130Te, and just three lepton number violating mechanisms (light and heavy neutrino mass mechanisms as well as R-parity breaking SUSY mechanism) being active, there are only four different solutions for the lepton violating parameters, provided that they are relatively real. In particular, assuming evidence of the 0nbb-decay of 76Ge, the effective neutrino Majorana mass |m_bb| can be almost uniquely extracted by utilizing other existing constraints (cosmological observations and tritium beta-decay ex...

  10. Measurement of the form factor ratio g1/f1 in LAMBDA beta decay

    International Nuclear Information System (INIS)

    Innes, W.R.

    1974-01-01

    The beta decay of 306 polarized lambdas was observed. The lambdas, which had a mean polarization of 70 percent, were produced by a 1.06 GeV/c π minus beam incident on a CH 2 target. The lambda decay particle trajectories were measured with a solenoidal magnetic spectrometer utilizing spark chambers with magnetostrictive readout. The beta decays were differentiated from other decay modes with an isobutane threshold Cherenkov counter. Using only information which depended upon the polarization, g 1 /f 1 was found to be 0.44- 0 . 13 +0 . 20 . Using only information independent of the polarization, g 1 /f 1 was found to be 0.62- 0 . 13 +0 . 17 . Combining all information yielded a value for g 1 /f 1 of 0.56- 0 . 11 +0 . 13 . Although these results taken by themselves are consistent with the Cabbibo theory prediction of 0.69, when combined with previous experiments there is a possibly significant discrepancy in the polarization dependent results. (U.S.)

  11. Beta-delayed proton emission from {sup 20}Mg

    Energy Technology Data Exchange (ETDEWEB)

    Lund, M.V.; Fynbo, H.O.U.; Howard, A.M.; Kirsebom, O.S.; Munch, M.; Riisager, K. [Aarhus University, Department of Physics and Astronomy, Aarhus C (Denmark); Andreyev, A.; Wadsworth, R. [University of York, Department of Physics, York (United Kingdom); Borge, M.J.G. [CSIC, Instituto de Estructura de la Materia, Madrid (Spain); CERN, ISOLDE, PH Department, Geneva 23 (Switzerland); Cederkaell, J. [Lund University, Department of Nuclear Physics, Lund (Sweden); Witte, H. de; Huyse, M.; Duppen, P. van [Instituut voor Kern- en Stralingsfysica, KU-Leuven, Leuven (Belgium); Fraile, L.M.; Vedia, V. [Universidad Complutense de Madrid, CEI Moncloa, Facultad de Ciencias Fisicas, Madrid (Spain); Greenlees, P.T.; Konki, J.; Rahkila, P. [University of Helsinki, Helsinki Institute of Physics, Helsinki (Finland); University of Jyvaeskylae, Department of Physics, Jyvaeskylae (Finland); Harkness-Brennan, L.J.; Judson, D.S.; Page, R.D. [University of Liverpool, Department of Physics, Oliver Lodge Laboratory, Liverpool (United Kingdom); Jonson, B.; Lindberg, S.; Nilsson, T. [Chalmers University of Technology, Department of Physics, Goeteborg (Sweden); Kurcewicz, J.; Madurga, M.; Rapisarda, E. [CERN, ISOLDE, PH Department, Geneva (Switzerland); Lazarus, I.; Pucknell, V. [STFC Daresbury, Daresbury, Warrington (United Kingdom); Lica, R. [CERN, ISOLDE, PH Department, Geneva (Switzerland); ' ' Horia Hulubei' ' National Institute of Physics and Nuclear Engineering, Magurele (Romania); Marginean, N.; Marginean, R.; Mihai, C.; Negret, A.; Pascu, S.; Rotaru, F.; Stanoiu, M.; Turturica, A. [' ' Horia Hulubei' ' National Institute of Physics and Nuclear Engineering, Magurele (Romania); Marroquin, I.; Nacher, E.; Perea, A.; Tengblad, O. [CSIC, Instituto de Estructura de la Materia, Madrid (Spain); Sotty, C. [Instituut voor Kern- en Stralingsfysica, KU-Leuven, Leuven (Belgium); ' ' Horia Hulubei' ' National Institute of Physics and Nuclear Engineering, Magurele (Romania); Warr, N. [Universitaet Koeln, Institut fuer Kernphysik, Koeln (Germany); Collaboration: IDS Collaboration

    2016-10-15

    Beta-delayed proton emission from {sup 20} Mg has been measured at ISOLDE, CERN, with the ISOLDE Decay Station (IDS) setup including both charged-particle and gamma-ray detection capabilities. A total of 27 delayed proton branches were measured including seven so far unobserved. An updated decay scheme, including three new resonances above the proton separation energy in {sup 20}Na and more precise resonance energies, is presented. Beta-decay feeding to two resonances above the Isobaric Analogue State (IAS) in {sup 20}Na is observed. This may allow studies of the 4032.9(2.4) keV resonance in {sup 19}Ne through the beta decay of {sup 20}Mg, which is important for the astrophysically relevant reaction {sup 15}O(α, γ){sup 19}Ne. Beta-delayed protons were used to obtain a more precise value for the half-life of {sup 20}Mg, 91.4(1.0) ms. (orig.)

  12. Double beta decay: a new formalism

    International Nuclear Information System (INIS)

    Hirsch, J.; Krmpotic, F.

    1990-01-01

    A study is made of the validity of those methods consisting in an average of solutions from initial and final solutions within the quasi-particle random phase approximation (QRPA) for double beta decay. A new method is developed that works with a single QRPA equation for the intermediate nucleus in which the correlations of the ground state for β - transitions are β + and vice versa. Numerical results agree in the different formulations, which avails the known averaging procedures while showing the greater operative simplicity of the proposed method for the case of the two neutrino mode in which the diagonalization process may be substituted by a matrix inversion. (Author). 13 refs., 1 fig., 1 tab

  13. Project for detecting the double beta decay of 136Xe

    International Nuclear Information System (INIS)

    Miyajima, M.; Sasaki, S.; Tawara, H.

    1992-01-01

    For detecting the nuclear double beta decay of 136 Xe, a liquid-xenon positive-ion collector and a time-of-flight mass spectrometer are under development for detecting the decay product 136 Ba. Two sets of lasers are used with the mass spectrometer. An Nd-YAG laser is used for sampling 136 Ba from the surface of the positive-ion collector electrode, and a dye laser pumped by an Nd-YAG laser is used for the selective ionization of 136 Ba. The principle of measurements as well as the experimental apparatus and procedures are described in detail, together with our future plans. (orig.)

  14. Gamow-Teller beta decay of proton-rich nuclei

    International Nuclear Information System (INIS)

    Klepper, O.; Rykaczewski, K.

    1990-11-01

    The beta decays of 48 Mn and of even-even nuclei near the double shell-closures at 100 Sn and 146 Gd are currently investigated at the GSI on-line mass separator. Their Gamow-Teller strength are surveyed in their present experimental status, together with related results from the ISOLDE (CERN) and ISOCELE (Orsay) separators, and are compared with predictions from different nuclear models. The strength of the 0 + → 1 + Gamow-Teller transitions is compiled in tables and graphs. (orig.)

  15. Neutrinoless double beta decay searches with 76Ge

    CERN Multimedia

    CERN. Geneva

    2017-01-01

    The search for neutrinoless double beta decay might be the only window to observe lepton number violation. Its observation would favour the leptogenesis mechanism for the explanation of the baryon asymmetry of the universe and is therefore considered to be of highest relevance. The isotope 76Ge has historically been most important for this search and the ongoing experiment GERDA has the lowest background of all experiments in the field. The talk reviews the motivation, the current status of experiments and future programs.

  16. Schematic model studies of double beta decay processes

    International Nuclear Information System (INIS)

    Civitarese, O.

    1996-01-01

    Some features of the nuclear matrix elements, for double beta decay transitions to a final ground state and to a final excited one and two-quadrupole phonon states, are presented and discussed in the framework of a schematic model. The competition between spin-flip and non-spin-flip transitions on the relevant nuclear matrix elements, the effects due to proton-neutron pairing correlations and the effects due to the inclusion of exchange terms in the QRPA matrix are discussed. (Author)

  17. The 76Ge(n,p)76Ga reaction and its relevance to searches for the neutrino-less double-beta decay of 76Ge

    Science.gov (United States)

    Tornow, W.; Bhike, Megha; Fallin, B.; Krishichayan, Fnu

    2015-10-01

    The 76Ge(n,p)76Ga reaction and the subsequent β decay of 76Ga to 76Ge has been used to excite the 3951.9 keV state of 76Ge, which decays by emission of a 2040.7 keV γ ray. Using HPGe detectors, the associated pulse-height signal may be undistinguishable from the potential signal produced in neutrino-less double-beta decay of 76Ge with its Q-value of 2039.0 keV. In the neutron energy range between 10 and 20 MeV the production cross section of the 2040.7 keV γ ray is approximately 0.1 mb. In the same experiment γ rays of energy 2037.9 keV resulting from the 76Ge(n, γ)77Ge reaction were clearly observed. Adding the 76Ge(n,n' γ)76Ge reaction, which also produces the 2040.7 keV γ ray with a cross section value of the order of 0.1 mb clearly shows that great care has to be taken to eliminate neutron-induced backgrounds in searches for neutrino-less double-beta decay of 76Ge. This work was supported by the U.S. DOE under Grant NO. DE-FG02-97ER41033.

  18. Beta decay of /sup 39/Cl

    International Nuclear Information System (INIS)

    Wang, G.; Warburton, E.K.; Alburger, D.E.

    1987-01-01

    The β decay of /sup 39/Cl, produced in the /sup 37/Cl(t,p)/sup 39/Cl reaction at E/sub t/ = 3.1 MeV, has been investigated with a Ge-NaI(Tl) Compton-suppression γ-ray spectrometer. Nineteen γ-ray transitions were observed, including 10 previously known. Precision energy measurements were carried out on six of the strongest lines. In the proposed decay scheme a weak new β-ray branch is established to the 2950-keV level of /sup 39/Ar, and the populations of /sup 39/Ar levels at 2093 and 2433 keV are accounted for by γ-ray decays from higher excited states. Spin-parity assignments are given

  19. Realistic fission models, new beta-decay half-lives and the r-process in neutron star mergers

    International Nuclear Information System (INIS)

    Shibagaki, S.; Kajino, T.; Chiba, S.; Lorusso, G.; Nishimura, S.; Mathews, G. J.

    2014-01-01

    Almost half of heavy nuclei beyond iron are considered to be produced by rapid neutron capture process (r-process). This process occurs in the neutron-rich environment such as core-collapse supernovae or neutron star mergers, but the main production site is still unknown. In the r-process of neutron star mergers, nuclear fission reactions play an important role. Also beta-decay half-lives of magic nuclei are crucial for the r-process. We have carried out r-process nucleosynthesis calculations based upon new theoretical estimates of fission fragment distributions and new beta-decay half-lives for N=82 nuclei measured at RIBF-RIKEN. We investigate the effect of nuclear fission on abundance patterns in the matter ejected from neutron star mergers with two different fission fragment mass distributions. We also discuss how the new experimental beta-decay half-lives affect the r-process

  20. Neutrinoless double-beta decay and dark matter search with GENIUS

    International Nuclear Information System (INIS)

    Klapdor-Kleingrothaus, H.V.; Kolb, S.

    2000-01-01

    The potential of the GENIUS (GErmanium in liquid NItrogen Underground Setup) experiment, proposed the successor of the Heidelberg-Moscow experiment, for the search for neutrinoless double-beta decay, the direct search for neutralino Cold Dark Matter and for other physics beyond the Standard Model are presented. The current status of the Heidelberg-Moscow experiment will be reviewed [ru

  1. Neutrinoless double-beta decay and dark matter search with GENIUS

    International Nuclear Information System (INIS)

    Klapdor-Kleingrothaus, H.V.; Kolb, St.

    2000-01-01

    The potential of the GENIUS (GErmanium in liquid NItrogen Underground Setup) experiment, proposed as the successor of the Heidelberg-Moscow experiment, for the search for neutrinoless double-beta decay, the direct search for neutralino Cold Dark Matter, and for other physics beyond the Standard Model will be presented. The current status of the Heidelberg-Moscow experiment will be reviewed

  2. Results on neutrinoless double beta decay search in GERDA. Background modeling and limit setting

    International Nuclear Information System (INIS)

    Becerici Schmidt, Neslihan

    2014-01-01

    The search for the neutrinoless double beta decay (0νββ) process is primarily motivated by its potential of revealing the possible Majorana nature of the neutrino, in which the neutrino is identical to its antiparticle. It has also the potential to yield information on the intrinsic properties of neutrinos, if the underlying mechanism is the exchange of a light Majorana neutrino. The Gerda experiment is searching for 0νββ decay of 76 Ge by operating high purity germanium (HPGe) detectors enriched in the isotope 76 Ge (∝ 87%), directly in ultra-pure liquid argon (LAr). The first phase of physics data taking (Phase I) was completed in 2013 and has yielded 21.6 kg.yr of data. A background index of B∼10 -2 cts/(keV.kg.yr) at Q ββ =2039 keV has been achieved. A comprehensive background model of the Phase I energy spectrum is presented as the major topic of this dissertation. Decomposition of the background energy spectrum into the individual contributions from different processes provides many interesting physics results. The specific activity of 39 Ar has been determined. The obtained result, A=(1.15±0.11) Bq/kg, is in good agreement with the values reported in literature. The contribution from 42 K decays in LAr to the background spectrum has yielded a 42 K( 42 Ar) specific activity of A=(106.2 -19.2 +12.7 ) μBq/kg, for which only upper limits exist in literature. The analysis of high energy events induced by α decays in the 226 Ra chain indicated a total 226 Ra activity of (3.0±0.9) μBq and a total initial 210 Po activity of (0.18±0.01) mBq on the p + surfaces of the enriched semi-coaxial HPGe detectors. The half life of the two-neutrino double beta (2νββ) decay of 76 Ge has been determined as T 1/2 2ν =(1.926±0.094).10 21 yr, which is in good agreement with the result that was obtained with lower exposure and has been published by the Gerda collaboration. According to the model, the background in Q ββ ±5 keV window is resulting from close

  3. Preliminary results from a study of the double beta decay of 150Nd

    International Nuclear Information System (INIS)

    Perillo, I.M.C.; Chan, Y.D.; Hurley, D.; Lesko, K.T.; McDonald, R.J.; Moorhead, M.E.; Norman, E.B.; Smith, A.R.; Stokstad, R.G.

    1996-01-01

    We report the preliminary results from a study of the double beta decay of 150 Nd to the first 0 + excited state of 150 Sm. Our data consists of 50 days of counting 5 kg of natural Nd 2 O 3 at the LBNL-Oroville low background facility. The deduced lower limit for the half life of this decay mode is 4.9.10 19 years. (orig.)

  4. An experimental investigation of double beta decay of 100Mo

    International Nuclear Information System (INIS)

    Dougherty, B.L.

    1988-01-01

    New limits on half-lives for several double beta decay modes of 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 96 Mo were used to assess remaining backgrounds. With 0.1 mole years of 100 Mo data collected, the lower half-life limits at 90% confidence were 2.7 /times/ 10 18 years for decay via the two-neutrino mode, 5.2 /times/10 19 years for decay with the emission of a Majoron, and 1.6 /times/ 10 20 years and 2.2 /times/ 10 21 years for neutrinoless 0 + → 2 + and 0 + → 0 + transitions, respectively. 50 refs., 38 figs., 11 tabs

  5. Neutrinoless double beta decay with 82SeF6 and direct ion imaging

    Science.gov (United States)

    Nygren, D. R.; Jones, B. J. P.; López-March, N.; Mei, Y.; Psihas, F.; Renner, J.

    2018-03-01

    We present a new neutrinoless double beta decay concept: the high pressure selenium hexafluoride gas time projection chamber. A promising new detection technique is outlined which combines techniques pioneered in high pressure xenon gas, such as topological discrimination, with the high Q-value afforded by the double beta decay isotope 82Se. The lack of free electrons in SeF6 mandates the use of an ion TPC. The microphysics of ion production and drift, which have many nuances, are explored. Background estimates are presented, suggesting that such a detector may achieve background indices of better than 1 count per ton per year in the region of interest at the 100 kg scale, and still better at the ton-scale.

  6. New limit for the half-life of double beta decay of {sup 94}Zr to the first excited state of {sup 94}Mo

    Energy Technology Data Exchange (ETDEWEB)

    Dokania, N.; Nanal, V.; Gupta, G.; Pillay, R.G.; Ghosh, C. [Tata Institute of Fundamental Research, Department of Nuclear and Atomic Physics, Mumbai (India); Pal, S. [Tata Institute of Fundamental Research, Pelletron Linac Facility, Mumbai (India); Rath, P.K. [University of Lucknow, Department of Physics, Lucknow (India); Tretyak, V.I. [Institute for Nuclear Research, Kyiv (Ukraine); Garai, A.; Krishnamoorthy, H. [Tata Institute of Fundamental Research, India-based Neutrino Observatory, Mumbai (India); Homi Bhabha National Institute, Mumbai (India); Raina, P.K. [Indian Institute of Technology, Department of Physics, Rupnagar (India); Bhushan, K.G. [Bhabha Atomic Research Centre, Technical Physics Division, Mumbai (India)

    2017-04-15

    Neutrinoless double beta decay is a phenomenon of fundamental interest in particle physics. The decay rates of double beta decay transitions to the excited states can provide input for Nuclear Transition Matrix Element calculations for the relevant two neutrino double beta decay process. It can be useful as supplementary information for the calculation of Nuclear Transition Matrix Element for the neutrinoless double beta decay process. In the present work, double beta decay of {sup 94}Zr to the 2{sup +}{sub 1} excited state of {sup 94}Mo at 871.1 keV is studied using a low background ∝ 230 cm{sup 3} HPGe detector. No evidence of this decay was found with a 232 g.y exposure of natural zirconium. The lower half-life limit obtained for the double beta decay of {sup 94}Zr to the 2{sup +}{sub 1} excited state of {sup 94}Mo is T{sub 1/2}(0ν + 2ν) > 3.4 x 10{sup 19} y at 90% C.L., an improvement by a factor of ∝ 4 over the existing experimental limit at 90% C.L. The sensitivity is estimated to be T{sub 1/2} (0ν + 2ν) > 2.0 x 10{sup 19} y at 90% C.L. using the Feldman-Cousins method. (orig.)

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

    International Nuclear Information System (INIS)

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

    1998-01-01

    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 outlook the present experimental situation with the 0νββ-decay searches for the SUSY. Upper limits on the R-parity violating 1st generation Yukawa coupling λ' 111 are derived from various 0νββ - experiments

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

    Energy Technology Data Exchange (ETDEWEB)

    Herrin, Steven [Stanford Univ., CA (United States)

    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.

  9. Double-beta decay investigation with highly pure enriched {sup 82}Se for the LUCIFER experiment

    Energy Technology Data Exchange (ETDEWEB)

    Beeman, J. W. [Lawrence Berkeley National Laboratory, 94720, Berkeley, CA (United States); Bellini, F. [Dipartimento di Fisica, Sapienza Università di Roma, 00185, Rome (Italy); INFN, Sezione di Roma, 00185, Rome (Italy); Benetti, P. [Dipartimento di Chimica, Università di Pavia, 27100, Pavia (Italy); INFN, Sezione di Pavia, 27100, Pavia (Italy); Cardani, L. [Dipartimento di Fisica, Sapienza Università di Roma, 00185, Rome (Italy); Physics Department, Princeton University, 08544, Princeton, NJ (United States); Casali, N. [Dipartimento di Fisica, Sapienza Università di Roma, 00185, Rome (Italy); INFN, Sezione di Roma, 00185, Rome (Italy)

    2015-12-13

    The LUCIFER project aims at deploying the first array of enriched scintillating bolometers for the investigation of neutrinoless double-beta decay of {sup 82}Se. The matrix which embeds the source is an array of ZnSe crystals, where enriched {sup 82}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 {sup 82}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 {sup 232}Th, {sup 238}U and {sup 235}U are respectively: <61, <110 and <74 μBq/kg at 90 % C.L. The extremely low-background conditions in which the measurement was carried out and the high radiopurity of the {sup 82}Se allowed us to establish the most stringent lower limits on the half-lives of the double-beta decay of {sup 82}Se to 0{sub 1}{sup +}, 2{sub 2}{sup +} and 2{sub 1}{sup +} excited states of {sup 82}Kr of 3.4·10{sup 22}, 1.3·10{sup 22} and 1.0·10{sup 22} y, respectively, with a 90 % C.L.

  10. Double-beta decay investigation with highly pure enriched {sup 82}Se for the LUCIFER experiment

    Energy Technology Data Exchange (ETDEWEB)

    Beeman, J.W. [Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Bellini, F.; Casali, N.; Ferroni, F.; Piperno, G. [Sapienza Universita di Roma, Dipartimento di Fisica, Rome (Italy); INFN, Sezione di Roma, Rome (Italy); Benetti, P. [Universita di Pavia, Dipartimento di Chimica, Pavia (Italy); INFN, Sezione di Pavia, Pavia (Italy); Cardani, L. [Sapienza Universita di Roma, Dipartimento di Fisica, Rome (Italy); Princeton University, Physics Department, Princeton, NJ (United States); Chiesa, D.; Clemenza, M.; Gironi, L.; Maino, M. [Universita di Milano-Bicocca, Dipartimento di Fisica, Milan (Italy); INFN, Sezione di Milano Bicocca, Milan (Italy); Dafinei, I.; Orio, F.; Tomei, C.; Vignati, M. [INFN, Sezione di Roma, Rome (Italy); Di Domizio, S. [INFN, Sezione di Genova, Genoa (Italy); Universita di Genova, Dipartimento di Fisica, Genoa (Italy); Giuliani, A. [Centre de Spectrometrie de Masse, Orsay (France); Gotti, C.; Pessina, G.; Previtali, E.; Rusconi, C. [INFN, Sezione di Milano Bicocca, Milan (Italy); Laubenstein, M.; Nisi, S.; Pattavina, L.; Pirro, S.; Schaeffner, K. [INFN, Laboratori Nazionali del Gran Sasso, Assergi (L' Aquila) (Italy); Nagorny, S.; Pagnanini, L. [Gran Sasso Science Institute, L' Aquila (Italy); Nones, C. [SPP Centre de Saclay, CEA, Irfu, Gif-sur-Yvette (France)

    2015-12-15

    The LUCIFER project aims at deploying the first array of enriched scintillating bolometers for the investigation of neutrinoless double-beta decay of {sup 82}Se. The matrix which embeds the source is an array of ZnSe crystals, where enriched {sup 82}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 {sup 82}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 {sup 232}Th, {sup 238}U and {sup 235}U are respectively: <61, <110 and <74 μBq/kg at 90 % C.L. The extremely low-background conditions in which the measurement was carried out and the high radiopurity of the {sup 82}Se allowed us to establish the most stringent lower limits on the half-lives of the double-beta decay of {sup 82}Se to 0{sub 1}{sup +}, 2{sub 2}{sup +} and 2{sub 1}{sup +} excited states of {sup 82}Kr of 3.4.10{sup 22}, 1.3.10{sup 22} and 1.0.10{sup 22} y, respectively, with a 90 % C.L. (orig.)

  11. Lifetime of the long-lived isomer of /sup 236/Np from. cap alpha. -,. beta. - and electron-capture decay measurements

    Energy Technology Data Exchange (ETDEWEB)

    Lindner, M.; Dupzyk, R.J.; Hoff, R.W.; Nagle, R.J. (California Univ., Livermore (USA). Lawrence Livermore National Lab.)

    1981-01-01

    The half-life of long-lived /sup 236/Np, due to ..cap alpha.., ..beta.. and electron-capture decay, was found to be 1.55 x 10/sup 5/ yr. Of all decays, 88% populate excited states in /sup 236/U and 12% populate levels in /sup 236/Pu. Lifetimes measured by growth of the ground states of /sup 236/U and /sup 236/Pu agree with values from corresponding ..gamma.. de-excitations in these daughter nuclei. Therefore, nearly all the electron-capture decays populate the 6/sup +/ level of the ground-state band in /sup 236/U. Similarly, essentially all the ..beta../sup -/ decay populates an analogous 6/sup +/ level in /sup 236/Pu, which de-excites through a previously unreported transition of 158.3 keV. If a very week ..gamma..-ray at 894 keV can be ascribed to a level in /sup 232/U populated by ..beta.. decay of /sup 232/Pa, its existence establishes a 0.2% ..cap alpha..-branching decay in /sup 236/Np.

  12. The beta decay asymmetry parameter of 35Ar

    International Nuclear Information System (INIS)

    Garnett, J.D.

    1987-11-01

    The beta decay asymmetry parameter for 35 Ar = 35 Cl + e + + nu/sub e/ has been remeasured in order to resolve a long standing puzzle. Previous asymmetry measurements, when combined with the comparative half-life, yield a value for the vector coupling constant, G/sub v/, that is in serious disagreement with the accepted value. We produced polarized 35 Ar by a (p,n) reaction on 35 Cl using the polarized proton beam provided by Lawrence Berkeley Laboratory's 88-Inch Cyclotron. The polarization of the 35 Ar was determined by measuring the asymmetry of the positrons produced in 35 Ar decay to the first excited state in 35 Cl (branching ratio = 1.3%) in coincidence with a 1219.4 keV gamma ray. Our result, A 0 = 0.49 +- 0.10, combined with the comparative half-life yields a value for G/sub v/ in agreement with the accepted value

  13. The Gerda experiment for the search of 0{nu}{beta}{beta} decay in {sup 76}Ge

    Energy Technology Data Exchange (ETDEWEB)

    Ackermann, K.H.; Altmann, M.; Becerici-Schmidt, N.; Caldwell, A.; Cossavella, F.; Lenz, D.; Liao, H.; Majorovits, B.; Mayer, S.; O' Shaughnessy, C.; Schubert, J.; Schulz, O.; Seitz, H.; Stelzer, F.; Vogt, S.; Volynets, O. [Max-Planck-Institut fuer Physik, Muenchen (Germany); Agostini, M.; Bode, T.; Budjas, D.; Janicsko Csathy, J.; Lazzaro, A.; Schoenert, S. [Technische Universitaet Muenchen, Physik Department and Excellence Cluster Universe, Munich (Germany); Allardt, M.; Barros, N.; Domula, A.; Lehnert, B.; Zuber, K. [Technische Universitaet Dresden, Institut fuer Kern- und Teilchenphysik, Dresden (Germany); Andreotti, E. [Institute for Reference Materials and Measurements, Geel (Belgium); Eberhard Karls Universitaet Tuebingen, Physikalisches Institut, Tuebingen (Germany); Bakalyarov, A.M.; Belyaev, S.T.; Lebedev, V.I.; Zhukov, S.V. [National Research Centre ' ' Kurchatov Institute' ' , Moscow (Russian Federation); Balata, M.; Ioannucci, L.; Junker, M.; Laubenstein, M.; Nisi, S.; Pandola, L. [LNGS, INFN Laboratori Nazionali del Gran Sasso, Assergi (Italy); Barabanov, I.; Bezrukov, L.; Denisov, A.; Gurentsov, V.; Kianovsky, S.; Kusminov, V.; Lubsandorzhiev, B.; Yanovich, E. [Institute for Nuclear Research of the Russian Academy of Sciences, Moscow (Russian Federation); Barnabe Heider, M. [Max Planck Institut fuer Kernphysik, Heidelberg (Germany); Technische Universitaet Muenchen, Physik Department and Excellence Cluster Universe, Munich (Germany); CEGEP St-Hyacinthe, Quebec (Canada); Baudis, L.; Benato, G.; Ferella, A.; Froborg, F.; Guthikonda, K.K.; Tarka, M.; Walter, M. [Physik Institut der Universitaet Zuerich, Zuerich (Switzerland); Bauer, C.; Hampel, W.; Heisel, M.; Heusser, G.; Hofmann, W.; Kankanyan, R.; Kihm, T.; Kiko, J.; Kirsch, A.; Knoepfle, K.T.; Lindner, M.; Lubashevskiy, A.; Machado, A.A.; Maneschg, W.; Oehm, J.; Salathe, M.; Schreiner, J.; Schwan, U.; Schwingenheuer, B.; Simgen, H.; Smolnikov, A.; Strecker, H.; Wagner, V.; Wegmann, A. [Max Planck Institut fuer Kernphysik, Heidelberg (Germany); Bellotti, E. [Universita Milano Bicocca, Dipartimento di Fisica, Milano (Italy); INFN Milano Bicocca, Milano (Italy); Belogurov, S.; Kornoukhov, V.N. [Institute for Nuclear Research of the Russian Academy of Sciences, Moscow (Russian Federation); Institute for Theoretical and Experimental Physics, Moscow (Russian Federation); Bettini, A.; Brugnera, R.; Garfagnini, A.; Hemmer, S.; Sada, C. [Dipartimento di Fisica e Astronomia dell' Universita di Padova, Padova (Italy); INFN Padova, Padova (Italy); Brudanin, V.; Egorov, V.; Kochetov, O.; Nemchenok, I.; Shevchik, E.; Zhitnikov, I.; Zinatulina, D. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Cattadori, C. [INFN Milano Bicocca, Milano (Italy); Chernogorov, A.; Demidova, E.V.; Kirpichnikov, I.V.; Vasenko, A.A. [Institute for Theoretical and Experimental Physics, Moscow (Russian Federation); Chkvorets, O. [Max Planck Institut fuer Kernphysik, Heidelberg (Germany); Laurentian University, Sudbury (Canada); D' Andragora, A. [LNGS, INFN Laboratori Nazionali del Gran Sasso, Assergi (Italy); Brookhaven National Laboratory, Upton, NY (United States); Di Vacri, A. [LNGS, INFN Laboratori Nazionali del Gran Sasso, Assergi (Italy); University ' ' G. d' Annunzio' ' di Chieti-Pescara, Department of Neurosciences and Imaging, Chieti (Italy); Falkenstein, R.; Freund, K.; Grabmayr, P.; Hegai, A.; Jochum, J.; Knapp, M.; Niedermeier, L.; Schmitt, C.; Sturm, K. von [Eberhard Karls Universitaet Tuebingen, Physikalisches Institut, Tuebingen (Germany); Frodyma, N.; Pelczar, K.; Wojcik, M.; Zuzel, G. [Jagiellonian University, Institute of Physics, Cracow (Poland); Gangapshev, A. [Max Planck Institut fuer Kernphysik, Heidelberg (Germany); Institute for Nuclear Research of the Russian Academy of Sciences, Moscow (Russian Federation); Gasparro, J. [Institute for Reference Materials and Measurements, Geel (Belgium); National Physical Laboratory, Teddigton (United Kingdom); Gazzana, S. [LNGS, INFN Laboratori Nazionali del Gran Sasso, Assergi (Italy); Max Planck Institut fuer Kernphysik, Heidelberg (Germany); Gonzalez de Orduna, R.; Hult, M.; Marissens, G. [Institute for Reference Materials and Measurements, Geel (Belgium); Gusev, K. [Joint Institute for Nuclear Research, Dubna (Russian Federation); National Research Centre ' ' Kurchatov Institute' ' , Moscow (Russian Federation); Technische Universitaet Muenchen, Physik Department and Excellence Cluster Universe, Munich (Germany); Inzhechik, L.V. [Institute for Nuclear Research of the Russian Academy of Sciences, Moscow (Russian Federation); Moscow Institute of Physics and Technology, Moscow (Russian Federation); Klimenko, A. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Max Planck Institut fuer Kernphysik, Heidelberg (Germany); Institute for Nuclear Research of the Russian Academy of Sciences, Moscow (Russian Federation); Kroeninger, K. [Max-Planck-Institut fuer Physik, Muenchen (Germany); U. Goettingen, II. Physikalisches Institut, Goettingen (Germany); U. Siegen, Department Physik, Siegen (Germany); Lippi, I.; Rossi Alvarez, C.; Stanco, L.; Ur, C.A. [INFN Padova, Padova (Italy); Liu, J. [Max-Planck-Institut fuer Physik, Muenchen (Germany); University of Tokyo, Kavli IPMU, Tokyo (Japan); Liu, X. [Shanghai Jiaotong University, Shanghai (China); Meierhofer, G. [Eberhard Karls Universitaet Tuebingen, Physikalisches Institut, Tuebingen (Germany); TUeV-SUeD, Muenchen (Germany); Peiffer, P. [Max Planck Institut fuer Kernphysik, Heidelberg (Germany); Karlsruhe Institute of Technology (KIT), Karlsruhe (Germany); Pullia, A.; Riboldi, S. [Universita degli Studi di Milano (Italy); INFN Milano, Dipartimento di Fisica, Milano (Italy); Ritter, F. [Eberhard Karls Universitaet Tuebingen, Physikalisches Institut, Tuebingen (Germany); Robert Bosch GmbH, Reutlingen (Germany); Shirchenko, M. [Joint Institute for Nuclear Research, Dubna (Russian Federation); National Research Centre ' ' Kurchatov Institute' ' , Moscow (Russian Federation); Trunk, U. [Max Planck Institut fuer Kernphysik, Heidelberg (Germany); DESY, Photon-Science Detector Group, Hamburg (Germany); Zavarise, P. [LNGS, INFN Laboratori Nazionali del Gran Sasso, Assergi (Italy); University of L' Aquila, Dipartimento di Fisica, L' Aquila (Italy)

    2013-03-15

    The Gerda collaboration is performing a search for neutrinoless double beta decay of {sup 76}Ge with the eponymous detector. The experiment has been installed and commissioned at the Laboratori Nazionali del Gran Sasso and has started operation in November 2011. The design, construction and first operational results are described, along with detailed information from the R and D phase. (orig.)

  14. Research and Development Supporting a Next Generation Germanium Double Beta Decay Experiment

    Science.gov (United States)

    Rielage, Keith; Elliott, Steve; Chu, Pinghan; Goett, Johnny; Massarczyk, Ralph; Xu, Wenqin

    2015-10-01

    To improve the search for neutrinoless double beta decay, the next-generation experiments will increase in source mass and continue to reduce backgrounds in the region of interest. A promising technology for the next generation experiment is large arrays of Germanium p-type point contact detectors enriched in 76-Ge. The experience, expertise and lessons learned from the MAJORANA DEMONSTRATOR and GERDA experiments naturally lead to a number of research and development activities that will be useful in guiding a future experiment utilizing Germanium. We will discuss some R&D activities including a hybrid cryostat design, background reduction in cabling, connectors and electronics, and modifications to reduce assembly time. We acknowledge the support of the U.S. Department of Energy through the LANL/LDRD Program.

  15. On possible contribution of a leptoquark intermediate boson mechanism in the free neutron beta decay

    International Nuclear Information System (INIS)

    Gaponov, Yu.V.

    2000-01-01

    A possible mechanism of the virtual leptoquark scalar intermediate boson exchange connected with a contribution of the right-handed nucleon currents to the free beta decay is demonstrated. The extension of the hypothesis can be associated with the realization of the same mechanism in the beta decay via the emission of right-handed neutrino (left-handed antineutrino). It is shown that a hypothesis of this kind leads to appearance of scalar and tensor terms in the effective Hamiltonian of weak interaction, and these terms include the right-handed neutrinos. The relevant experimental data are discussed [ru

  16. Beta decay rates of nuclei with 65

    Indian Academy of Sciences (India)

    of spectral averaging theory for two-body nuclear Hamiltonian in a large nuclear shell ... Beta decay rates; supernova evolution; spectral distribution method. ... level density formula, Wigner's treatment of spectral fluctuations using matrix en-.

  17. Neutrinoless double-beta decay - Status of evidence and future

    International Nuclear Information System (INIS)

    Klapdor-Kleingrothaus, H.V.

    2002-01-01

    Double-beta decay is indispensable to solve the question of the neutrino mass matrix together with ν oscillation experiments. Recent analysis of the most sensitive experiment in the last eight years - the Heidelberg-Moscow experiment in Gran Sasso - yields evidence for the neutrinoless decay mode at a 97% C.L. This result is the first indication for lepton number violation and for the neutrino to be a Majorana particle. We give the present status of the analysis in these proceedings. It excludes several of the neutrino mass scenarios allowed from present neutrino oscillation experiments - essentially only degenerate and partially degenerate mass scenarios survive. To improve the present result, considerably enlarged experiments are required, such as GENIUS. A GENIUS Test Facility has just been funded and will come into operation by the end of 2002

  18. Beta decays of 126Cd and 126In to levels in 126In and 126Sn

    International Nuclear Information System (INIS)

    Gartner, M.L.

    1979-01-01

    A study of the beta decays of 126 Cd and 126 In using the TRISTAN on-line isotope separator facility is reported. Gamma-ray singles measurements were made for both decays usng Ge(Li) and LEPS (low energy photon spectrometer) detectors. In addition, gamma--gamma coincidence measurements and gamma multiscale measurements were made for both decays using Ge(Li) detectors. The half-life for 126 Cd was determined to be 0.506 +- 0.015 sec., and the half-lives for the low- and high-spin 126 In isomers were determined to be 1.83 +- 0.11 sec. and 1.96 +- 0.10 sec., respectively. A total of 11 gamma rays were observed in the decay of 126 Cd, and all but one were placed in a level scheme for 126 In. A total of 48 gamma rays were observed in the decay of the low- and high-spin 126 In isomers and all were placed in a level scheme for 126 Sn. Spin and parity assignments were deduced, whenever possible, on the basis of logft values and gamma decay selection rules. The 126 In decay schemes (one has been proposed for each isomer) are compared with earlier decay studies and with results from 124 Sn(t,p) 126 Sn reaction experiments. The systematics associated with the level schemes are discussed and a comparison is made with the nuclear shell model. 49 references

  19. Double beta decay, neutrino physics, nuclear structure and isospin and spin-isospin symmetries

    International Nuclear Information System (INIS)

    Krmpotic, F.

    1989-12-01

    Prominent features of the double beta decay processes are reviewed. Emphasis is placed on the neutrino masses and the quasiparticle random phase approximation (GRPA). The suppression mechanism for the ββ-decay transition rates, proposed by Vogel and Zirnbauer, is found to be closely related to the restoration of SU(4) symmetry. It is suggested that the extreme sensitivity of the ββ-decay amplitude on the proton-neutron coupling is a consequence of the explicit violation of the SU(4) symmetry and therefore an artifact of the model. A prescription is given for fixing this interaction strength within the GRPA itself, which in this way acquires predicting power on both single and double β-decay lifetimes. (author) [pt

  20. Double beta decay - physics beyond the standard model now, and in future (Genius)

    Energy Technology Data Exchange (ETDEWEB)

    Klapdor-Kleingrothaus, H.V.

    1998-08-01

    Nuclear double beta decay provides an extraordinarily broad potential to search for beyond standard model physics, probing already now the TeV scale, on which new physics should manifest itself. These possibilities are reviewed here. First, the results of present generation experiments are presented. The most sensitive one of them - the Heidelberg-Moscow experiment in the Gran Sasso - probes the electron mass now in the sub eV region and will reach a limit of {proportional_to}0.1 eV in a few years. Basing to a large extent on the theoretical work of the Heidelberg double beta group in the last two years, results are obtained also for SUSY models (R-parity breaking, sneutrino mass), leptoquarks (leptoquark-Higgs coupling), compositeness, right-handed W boson mass and others. These results are comfortably competitive to corresponding results from high-energy accelerators like TEVATRON, HERA, etc. Second, future perspectives of {beta}{beta} research are discussed. A new Heidelberg experimental proposal (GENIUS) is presented which would allow to increase the sensitivity for Majorana neutrino masses from the present level of at best 0.1 eV down to 0.01 or even 0.001 eV. Its physical potential would be a breakthrough into the multi-TeV range for many beyond standard models. Its sensitivity for neutrino oscillation parameters would be larger than of all present terrestrial neutrino oscillation experiments and of those planned for the future. (orig.)

  1. Results on neutrinoless double beta decay search in GERDA. Background modeling and limit setting

    Energy Technology Data Exchange (ETDEWEB)

    Becerici Schmidt, Neslihan

    2014-07-22

    The search for the neutrinoless double beta decay (0νββ) process is primarily motivated by its potential of revealing the possible Majorana nature of the neutrino, in which the neutrino is identical to its antiparticle. It has also the potential to yield information on the intrinsic properties of neutrinos, if the underlying mechanism is the exchange of a light Majorana neutrino. The Gerda experiment is searching for 0νββ decay of {sup 76}Ge by operating high purity germanium (HPGe) detectors enriched in the isotope {sup 76}Ge (∝ 87%), directly in ultra-pure liquid argon (LAr). The first phase of physics data taking (Phase I) was completed in 2013 and has yielded 21.6 kg.yr of data. A background index of B∼10{sup -2} cts/(keV.kg.yr) at Q{sub ββ}=2039 keV has been achieved. A comprehensive background model of the Phase I energy spectrum is presented as the major topic of this dissertation. Decomposition of the background energy spectrum into the individual contributions from different processes provides many interesting physics results. The specific activity of {sup 39}Ar has been determined. The obtained result, A=(1.15±0.11) Bq/kg, is in good agreement with the values reported in literature. The contribution from {sup 42}K decays in LAr to the background spectrum has yielded a {sup 42}K({sup 42}Ar) specific activity of A=(106.2{sub -19.2}{sup +12.7}) μBq/kg, for which only upper limits exist in literature. The analysis of high energy events induced by α decays in the {sup 226}Ra chain indicated a total {sup 226}Ra activity of (3.0±0.9) μBq and a total initial {sup 210}Po activity of (0.18±0.01) mBq on the p{sup +} surfaces of the enriched semi-coaxial HPGe detectors. The half life of the two-neutrino double beta (2νββ) decay of {sup 76}Ge has been determined as T{sub 1/2}{sup 2ν}=(1.926±0.094).10{sup 21} yr, which is in good agreement with the result that was obtained with lower exposure and has been published by the Gerda collaboration

  2. The beta-decay of 48Mn: improved data on Gamow-Teller quenching

    International Nuclear Information System (INIS)

    Szerypo, J.; Bazin, D.; Brown, B.A.

    1991-01-01

    Beta-decay studies of very proton-rich nuclides allow to investigate the phenomenon of quenching of Gamow-Teller transitions. A presentation of the experimental techniques is followed by the discussion of preliminray results of the measurements in comparison to shell-model calculations. A corresponding reinvestigation is discussed. A mass-separated 48 Mn beam was used from 12 C( 40 Ca,p3n) reactions. The 48 Mn decay spectroscopy was performed simultaneously in two beam lines of the mass separator. (G.P.) 13 refs.; 2 figs

  3. Evolution of single-particle structure and beta-decay near 78Ni

    Directory of Open Access Journals (Sweden)

    Borzov I. N.

    2012-12-01

    Full Text Available The extended self-consistent beta-decay model has been applied for bet-decay rates and delayed neutron emission probabilities of spherical neutron-rich isotopes near the r-process paths. Unlike a popular global FRDM+RPA model, in our fully microscopic approach, the Gamow-Teller and first-forbidden decays are treated on the same footing. The model has been augmented by blocking of the odd particle in order to account for important ground-state spin-parity inversion effect which has been shown to exist in the region of the most neutron-rich doubly-magic nucleus 78Ni. Finally, a newly developed form of density functional DF3a has been employed which gives a better spin-orbit splitting due to the modified tensor components of the density functional.

  4. Evaluation of beta intensity data in nuclear decay schemes: Comments on some pitfalls

    International Nuclear Information System (INIS)

    Reich, C.W.

    1987-02-01

    Some of the problems that arise in the evaluation of decay-schemes data to obtain values for the intensities of beta transitions are discussed. As examples of these problems, the decay schemes of 87 Br and 233 Pa are examined. No specific solutions to these problems are offered; but by pointing out to the participants in the International Nuclear Structure and Decay Data Evaluation Network, and to others, it is hoped that a general understanding of them can be gained, which may ultimately lead to a consistent means of dealing with them. 14 refs., 2 figs

  5. The large enriched germanium experiment for neutrinoless double beta decay (LEGEND)

    Science.gov (United States)

    Abgrall, N.; Abramov, A.; Abrosimov, N.; Abt, I.; Agostini, M.; Agartioglu, M.; Ajjaq, A.; Alvis, S. I.; Avignone, F. T.; Bai, X.; Balata, M.; Barabanov, I.; Barabash, A. S.; Barton, P. J.; Baudis, L.; Bezrukov, L.; Bode, T.; Bolozdynya, A.; Borowicz, D.; Boston, A.; Boston, H.; Boyd, S. T. P.; Breier, R.; Brudanin, V.; Brugnera, R.; Busch, M.; Buuck, M.; Caldwell, A.; Caldwell, T. S.; Camellato, T.; Carpenter, M.; Cattadori, C.; Cederkäll, J.; Chan, Y.-D.; Chen, S.; Chernogorov, A.; Christofferson, C. D.; Chu, P.-H.; Cooper, R. J.; Cuesta, C.; Demidova, E. V.; Deng, Z.; Deniz, M.; Detwiler, J. A.; Di Marco, N.; Domula, A.; Du, Q.; Efremenko, Yu.; Egorov, V.; Elliott, S. R.; Fields, D.; Fischer, F.; Galindo-Uribarri, A.; Gangapshev, A.; Garfagnini, A.; Gilliss, T.; Giordano, M.; Giovanetti, G. K.; Gold, M.; Golubev, P.; Gooch, C.; Grabmayr, P.; Green, M. P.; Gruszko, J.; Guinn, I. S.; Guiseppe, V. E.; Gurentsov, V.; Gurov, Y.; Gusev, K.; Hakenmüeller, J.; Harkness-Brennan, L.; Harvey, Z. R.; Haufe, C. R.; Hauertmann, L.; Heglund, D.; Hehn, L.; Heinz, A.; Hiller, R.; Hinton, J.; Hodak, R.; Hofmann, W.; Howard, S.; Howe, M. A.; Hult, M.; Inzhechik, L. V.; Csáthy, J. Janicskó; Janssens, R.; Ješkovský, M.; Jochum, J.; Johansson, H. T.; Judson, D.; Junker, M.; Kaizer, J.; Kang, K.; Kazalov, V.; Kermadic, Y.; Kiessling, F.; Kirsch, A.; Kish, A.; Klimenko, A.; Knöpfle, K. T.; Kochetov, O.; Konovalov, S. I.; Kontul, I.; Kornoukhov, V. N.; Kraetzschmar, T.; Kröninger, K.; Kumar, A.; Kuzminov, V. V.; Lang, K.; Laubenstein, M.; Lazzaro, A.; Li, Y. L.; Li, Y.-Y.; Li, H. B.; Lin, S. T.; Lindner, M.; Lippi, I.; Liu, S. K.; Liu, X.; Liu, J.; Loomba, D.; Lubashevskiy, A.; Lubsandorzhiev, B.; Lutter, G.; Ma, H.; Majorovits, B.; Mamedov, F.; Martin, R. D.; Massarczyk, R.; Matthews, J. A. J.; McFadden, N.; Mei, D.-M.; Mei, H.; Meijer, S. J.; Mengoni, D.; Mertens, S.; Miller, W.; Miloradovic, M.; Mingazheva, R.; Misiaszek, M.; Moseev, P.; Myslik, J.; Nemchenok, I.; Nilsson, T.; Nolan, P.; O'Shaughnessy, C.; Othman, G.; Panas, K.; Pandola, L.; Papp, L.; Pelczar, K.; Peterson, D.; Pettus, W.; Poon, A. W. P.; Povinec, P. P.; Pullia, A.; Quintana, X. C.; Radford, D. C.; Rager, J.; Ransom, C.; Recchia, F.; Reine, A. L.; Riboldi, S.; Rielage, K.; Rozov, S.; Rouf, N. W.; Rukhadze, E.; Rumyantseva, N.; Saakyan, R.; Sala, E.; Salamida, F.; Sandukovsky, V.; Savard, G.; Schönert, S.; Schütz, A.-K.; Schulz, O.; Schuster, M.; Schwingenheuer, B.; Selivanenko, O.; Sevda, B.; Shanks, B.; Shevchik, E.; Shirchenko, M.; Simkovic, F.; Singh, L.; Singh, V.; Skorokhvatov, M.; Smolek, K.; Smolnikov, A.; Sonay, A.; Spavorova, M.; Stekl, I.; Stukov, D.; Tedeschi, D.; Thompson, J.; Van Wechel, T.; Varner, R. L.; Vasenko, A. A.; Vasilyev, S.; Veresnikova, A.; Vetter, K.; von Sturm, K.; Vorren, K.; Wagner, M.; Wang, G.-J.; Waters, D.; Wei, W.-Z.; Wester, T.; White, B. R.; Wiesinger, C.; Wilkerson, J. F.; Willers, M.; Wiseman, C.; Wojcik, M.; Wong, H. T.; Wyenberg, J.; Xu, W.; Yakushev, E.; Yang, G.; Yu, C.-H.; Yue, Q.; Yumatov, V.; Zeman, J.; Zeng, Z.; Zhitnikov, I.; Zhu, B.; Zinatulina, D.; Zschocke, A.; Zsigmond, A. J.; Zuber, K.; Zuzel, G.

    2017-10-01

    The observation of neutrinoless double-beta decay (0νββ) would show that lepton number is violated, reveal that neu-trinos are Majorana particles, and provide information on neutrino mass. A discovery-capable experiment covering the inverted ordering region, with effective Majorana neutrino masses of 15 - 50 meV, will require a tonne-scale experiment with excellent energy resolution and extremely low backgrounds, at the level of ˜0.1 count /(FWHM.t.yr) in the region of the signal. The current generation 76Ge experiments GERDA and the Majorana Demonstrator, utilizing high purity Germanium detectors with an intrinsic energy resolution of 0.12%, have achieved the lowest backgrounds by over an order of magnitude in the 0νββ signal region of all 0νββ experiments. Building on this success, the LEGEND collaboration has been formed to pursue a tonne-scale 76Ge experiment. The collaboration aims to develop a phased 0νββ experimental program with discovery potential at a half-life approaching or at 1028 years, using existing resources as appropriate to expedite physics results.

  6. Shapes of the $^{192,190}$Pb ground states from beta decay studies using the total absorption technique

    CERN Document Server

    Estevez Aguado, M.E.; Agramunt, J.; Rubio, B.; Tain, J.L.; Jordan, D.; Fraile, L.M.; Gelletly, W.; Frank, A.; Csatlos, M.; Csige, L.; Dombradi, Zs.; Krasznahorkay, A.; Nacher, E.; Sarriguren, P.; Borge, M.J.G.; Briz, J.A.; Tengblad, O.; Molina, F.; Moreno, O.; Kowalska, M.; Fedosseev, V.N.; Marsh, B.A.; Fedorov, D.V.; Molkanov, P.L.; Andreyev, A.N.; Seliverstov, M.D.; Burkard, K.; Huller, W.

    2015-01-01

    The beta decay of $^{192,190}$Pb has been studied using the total absorption technique at the ISOLDE(CERN) facility. The beta-decay strength deduced from the measurements, combined with QRPA theoretical calculations, allow us to infer that the ground states of the $^{192,190}$Pb isotopes are spherical. These results represent the first application of the shape determination method using the total absorption technique for heavy nuclei and in a region where there is considerable interest in nuclear shapes and shape effects.

  7. Weak decays and double beta decay. Annual progress report, January 1, 1982-December 31, 1982

    International Nuclear Information System (INIS)

    Nicholson, H.W.

    1982-08-01

    Work has continued in collaboration with experimenters from Yale, Brookhaven and Pittsburgh (Brookhaven experiment 702) to measure asymmetries in the decays of polarized Σ + 's into protons and neutral pions and of polarized Σ - 's into neutrons and negative pions. A short experiment was carried out in the Brookhaven AGS A2 test beam to measure the efficiency of a cylindrical shower counter essential for measuring the asymmetry parameter in the rare decay of polarized Σ + 's into protons and gammas. An electronic controller to stabilize the magnetic field of the superconducting, polarized target magnet was also designed and built at Mount Holyoke, and it functioned extremely well during a six week May to June run. Also, the design of an experiment to search for double beta decay in Molybdenum 100 is briefly described. A group consisting of five experimenters from LBL and two from Mount Holyoke hope to make a formal proposal in September to the LBL administration to begin work on this experiment late this year and during the next calendar year

  8. New results for double-beta decay of {sup 100}Mo to excited final states of {sup 100}Ru using the TUNL-ITEP apparatus

    Energy Technology Data Exchange (ETDEWEB)

    Kidd, M.F.; Esterline, J.H. [Department of Physics, Duke University and Triangle Universities Nuclear Laboratory, Durham, NC 27708-0308 (United States); Tornow, W. [Department of Physics, Duke University and Triangle Universities Nuclear Laboratory, Durham, NC 27708-0308 (United States)], E-mail: tornow@tunl.duke.edu; Barabash, A.S.; Umatov, V.I. [Institute for Theoretical and Experimental Physics, 117259 Moscow (Russian Federation)

    2009-04-15

    The coincidence detection efficiency of the TUNL-ITEP apparatus designed for measuring half-life times of two-neutrino double-beta (2{nu}{beta}{beta}) decay transitions to excited final states in daughter nuclei has been measured with a factor of 2.4 improved accuracy. In addition, the previous measuring time of 455 days for the study of the {sup 100}Mo 2{nu}{beta}{beta} decay to the first excited 0{sub 1}{sup +} state in {sup 100}Ru has been increased by 450 days, and a new result (combined with the previous measurement obtained with the same apparatus) for this transition is presented: T{sub 1/2}=[5.5{sub -0.8}{sup +1.2}(stat){+-}0.3(syst)]x10{sup 20} yr. Measured 2{nu}{beta}{beta} decay half-life times to excited states can be used to test the reliability of nuclear matrix element calculations needed for determining the effective neutrino mass from zero-neutrino double-beta decay data. We also present new limits for transitions to higher excited states in {sup 100}Ru which, if improved, may be of interest for more exotic conjectures, like a bosonic component to neutrino statistics.

  9. Study and conception of the decay ring of a neutrino facility using the {beta} decays of the helium 6 and neon 18 nuclei produced by an intense beam of protons hitting various targets; Etude et conception de l'anneau de desintegration d'une usine a neutrinos utilisant les decroissances {beta} des noyaux helium 6 et neon 18 produits par un faisceau intense de protons frappant diverses cibles

    Energy Technology Data Exchange (ETDEWEB)

    Chance, A

    2007-09-15

    The study of the neutrino oscillation between its different flavours needs pure and very intense flux of energetic, well collimated neutrinos with a well determined energy spectrum. So, a dedicated machine seems necessary nowadays. Among the different concepts of neutrino facilities, the one which will be studied here, called Beta-Beams, lies on the neutrino production by beta decay of radioactive ions after their acceleration. More precisely, the thesis is focused on the study and the design of the race-track-shaped storage ring of the high energy ions. Its aim is to store the ions until decaying. After a brief description of the neutrino oscillation mechanism and a review of the different experiments, an introduction to the neutrino facility concept and more precisely to the Beta-Beams will be given. Then, the issues linked to the Beta-Beams will be presented. After a description of the beam transport formalism, a first design and the optical properties of the ring will be then given. The effects of the misalignment and of the field errors in the dipoles have been studied. The dynamic aperture optimization is then realized. Handling of the decay losses or the energy collimation scheme will be developed. The off-momentum injection needed in presence of a circulating beam will be explained. Finally, the specific radiofrequency program needed by the beam merging will be presented. (author)

  10. First direct observation of bound-state beta-decay. Measurements of branching and lifetime of {sup 207}Tl{sup 81+} fragments

    Energy Technology Data Exchange (ETDEWEB)

    Boutin, D.

    2005-08-01

    The first experimental observation of bound-state beta-decay showed, that due solely to the electron stripping, a stable nuclide, e.g. {sup 163}Dy, became unstable. Also a drastic modification of the half-life of bare {sup 187}Re, from 4.12(2) x 10{sup 10} years down to 32.9(20) years, could be observed. It was mainly due to the possibility for the mother nuclide to decay into a previously inaccessible nuclear level of the daughter nuclide. It was proposed to study a nuclide where this decay mode was competing with continuum-state beta-decay, in order to measure their respective branchings. The ratio {beta}{sub b}/{beta}{sub c} could also be evaluated for the first time. {sup 207}Tl was chosen due to its high atomic number, and Q-value of about 1.4 MeV, small enough to enhance the {beta}{sub b} probability and large enough to allow the use of time-resolved Schottky Mass Spectrometry (SMS) to study the evolution of mother and bound-state beta-decay daughter ions. The decay properties of the ground state and isomeric state of {sup 207}Tl{sup 81+} have been investigated at the GSI accelerator facility in two separate experiments. For the first time {beta}-decay where the electron could go either to a bound state (atomic orbitals) and lead to {sup 207}Pb{sup 81+} as a daughter nuclide, or to a continuum state and lead to {sup 207}Pb{sup 82+}, has been observed. The respective branchings of these two processes could be measured as well. The deduced total nuclear half-life of 255(17) s for {sup 207}Tl{sup 81+}, was slightly modified with respect to the half-life of the neutral atom of 286(2) s. It was nevertheless in very good agreement with calculations based on the assumption that the beta-decay was following an allowed type of transition. The branching {beta}{sub b}/{beta}{sub c}=0.192(20), was also in very good agreement with the same calculations. The application of stochastic precooling allowed to observe in addition the 1348 keV short-lived isomeric state of {sup

  11. Search of Neutrinoless Double Beta Decay with the GERDA Experiment

    Science.gov (United States)

    Agostini, M.; Allardt, M.; Bakalyarov, A. M.; Balata, M.; Barabanov, I.; Baudis, L.; Bauer, C.; Becerici-Schmidt, N.; Bellotti, E.; Belogurov, S.; Belyaev, S. T.; Benato, G.; Bettini, A.; Bezrukov, L.; Bode, T.; Borowicz, D.; Brudanin, V.; Brugnera, R.; Budjáš, D.; Caldwell, A.; Cattadori, C.; Chernogorov, A.; D'Andrea, V.; Demidova, E. V.; Domula, A.; Doroshkevich, E.; Egorov, V.; Falkenstein, R.; Fedorova, O.; Freund, K.; Frodyma, N.; Gangapshev, A.; Garfagnini, A.; Gooch, C.; Gotti, C.; Grabmayr, P.; Gurentsov, V.; Gusev, K.; Hampel, W.; Hegai, A.; Heisel, M.; Hemmer, S.; Heusser, G.; Hoffmann, W.; Hult, M.; Inzhechik, L. V.; Ioannucci, L.; Janicksó Csáthy, J.; Jochum, J.; Junker, M.; Kazalov, V.; Kihm, T.; Kirpichnikov, I. V.; Kirsch, A.; Klimenko, A.; 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.; Marissens, G.; Medinaceli, E.; Misiaszek, M.; Moseev, P.; Nemchenok, I.; Nisi, S.; Palioselitis, D.; Panas, K.; Pandola, L.; Pelczar, K.; Pessina, G.; Pullia, A.; Reissfelder, M.; Riboldi, S.; Rumyantseva, N.; Sada, C.; Salathe, M.; Schmitt, C.; Schneider, B.; Schreiner, J.; Schulz, O.; Schwingenheuer, B.; Schönert, S.; Seitz, H.; Selivalenko, O.; Shevchik, E.; Shirchenko, M.; Simgen, H.; Smolnikov, A.; Stanco, L.; Stepaniuk, M.; Strecker, H.; Ur, C. A.; 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.; Zavarise, P.; Zhitnikov, I.; Zhukov, S. V.; Zinatulina, D.; Zuber, K.; Zuzel, G.

    2016-04-01

    The GERDA (GERmanium Detector Array) is an experiment for the search of neutrinoless double beta decay (0 νββ) in 76Ge, located at Laboratori Nazionali del Gran Sasso of INFN (Italy). In the first phase of the experiment, a 90% confidence level (C.L.) sensitivity of 2.4 ṡ1025 yr on the 0 νββ decay half-life was achieved with a 21.6 kgṡyr exposure and an unprecedented background index in the region of interest of 10-2 counts/(keVṡkgṡyr). No excess of signal events was found, and an experimental lower limit on the half-life of 2.1 ṡ 1025 yr (90% C.L.) was established. Correspondingly, the limit on the effective Majorana neutrino mass is mee < 0.2- 0.4 eV, depending on the considered nuclear matrix element. The previous claim for evidence of a 0 νββ decay signal is strongly disfavored, and the field of research is open again.

  12. Simulation of double beta decay in the ''SeXe'' TPC

    Science.gov (United States)

    Mauger, F.

    2007-04-01

    In 2004, the NEMO collaboration has started some preliminary studies for a next-generation double beta decay experiment: SuperNEMO. The possibility to use a large gaseous TPC has been investigated using simulation and extrapolation of former experiments. In this talk, I report on the reasons why such techniques have not been selected in 2004 and led the NEMO collaboration to reuse the techniques implemented within the NEMO3 detector.

  13. Neutrinoless double beta decay and lepton flavor violation

    International Nuclear Information System (INIS)

    Cirigliano, V.; Kurylov, A.; Vogel, P.; Ramsey-Musolf, M.J.

    2004-01-01

    We point out that extensions of the standard model with low scale (∼TeV) lepton number violation (LNV) generally lead to a pattern of lepton flavor violation (LFV) experimentally distinguishable from the one implied by models with grand unified theory scale LNV. As a consequence, muon LFV processes provide a powerful diagnostic tool to determine whether or not the effective neutrino mass can be deduced from the rate of neutrinoless double beta decay. We discuss the role of μ→eγ and μ→e conversion in nuclei, which will be studied with high sensitivity in forthcoming experiments

  14. The CUORE neutrinoless double-beta decay experiment

    International Nuclear Information System (INIS)

    Banks, T.I.

    2014-01-01

    CUORE is an upcoming experiment designed to search for neutrinoless double-beta decay (0νββ) decay in 130 Te. Observation of the process would be a major finding because it would unambiguously establish that neutrinos are Majorana particles (i.e., their own antiparticles) as well as provide information about the absolute neutrino mass scale. The CUORE detector will consist of 988 identical TeO 2 crystal bolometers (containing 206 kg of 130 Te in total) arranged into 19 towers and cooled to about 10 mK at the underground Gran Sasso National Laboratory (LNGS), Italy, which provides the low-background environment necessary for rare event searches of this kind. A predecessor experiment, Cuoricino, ran from 2003-2008 at LNGS and served as a learning ground for CUORE, which will be 20 times larger and exhibit much lower backgrounds. The CUORE detector assembly line has produced its first tower, designated CUORE-0, which is expected to come online in the former Cuoricino cryostat in October 2012 and take data for about 2 years while 19 CUORE towers are assembled. CUORE data taking is expected for 2015-2019. (author)

  15. The beta strength function structure in β+ decay of lutetium, thulium and cesium isotopes

    International Nuclear Information System (INIS)

    Alkhazov, G.D.; Bykov, A.A.; Vitman, V.D.; Naumov, Yu.V.; Orlov, S.Yu.

    1981-01-01

    The spectra of total γ-absorption in the decays of some Lutecium, Thulium and Cesium isotopes have been measured. The probabilities for level population in the decay of the isotopes have been determined. The deduced beta strength functions reveal pronounced structure. Calculations of the strength functions using the Saxon-Woods potential and the residual Gamow-Teller interaction are presented. It is shown that in β + decay of light Thulium and Cesium isotopes the strength function comprises more than 70% of the Gamow-Teller excitations with μsub(tau) = +1. This result is the first direct observation of the Gamow-Teller resonance in β + decay of nuclei with Tsub(z) > O. (orig.)

  16. The LPCTrap experiment: measurement of the {beta}-{nu} angular correlation in {sup 6}He{sup +} decay using a transparent Paul trap

    Energy Technology Data Exchange (ETDEWEB)

    Velten, Ph., E-mail: velten@lpccaen.in2p3.fr; Ban, G.; Durand, D.; Flechard, X.; Lienard, E.; Mauger, F.; Mery, A.; Naviliat-Cuncic, O.; Rodriguez, D.; Thomas, J. C. [Universite de Caen, LPC Caen, ENSICAEN (France)

    2011-07-15

    The LPCTrap experiment is devoted to the precise measurement of the {beta}-{nu} angular correlation parameter, a{sub {beta}{nu}}, in the pure Gamow-Teller decay of {sup 6}He{sup +}. This experiment is motivated by the search of the presence of tensor type contributions in the weak interaction. The radioactive source is confined in a transparent Paul trap installed at LIRAT, the low energy beam line of the SPIRAL facility. The {beta}-{nu} correlation is studied by measuring the time of flight of the recoil ions detected in coincidence with the {beta} particles. During the last experiment, a total of 4 Multiplication-Sign 10{sup 6} coincidence events have been recorded which would enable to determine the coefficient with a statistical uncertainty of 0.5%. The status of the analysis is presented in this contribution.

  17. Demonstration of Single-Barium-Ion Sensitivity for Neutrinoless Double-Beta Decay Using Single-Molecule Fluorescence Imaging

    Energy Technology Data Exchange (ETDEWEB)

    McDonald, A. D.; Jones, B. J. P.; Nygren, D. R.; Adams, C.; Álvarez, V.; Azevedo, C. D. R.; Benlloch-Rodríguez, J. M.; Borges, F. I. G. M.; Botas, A.; Cárcel, S.; Carrión, J. V.; Cebrián, S.; Conde, C. A. N.; Díaz, J.; Diesburg, M.; Escada, J.; Esteve, R.; Felkai, R.; Fernandes, L. M. P.; Ferrario, P.; Ferreira, A. L.; Freitas, E. D. C.; Goldschmidt, A.; Gómez-Cadenas, J. J.; González-Díaz, D.; Gutiérrez, R. M.; Guenette, R.; Hafidi, K.; Hauptman, J.; Henriques, C. A. O.; Hernandez, A. I.; Hernando Morata, J. A.; Herrero, V.; Johnston, S.; Labarga, L.; Laing, A.; Lebrun, P.; Liubarsky, I.; López-March, N.; Losada, M.; Martín-Albo, J.; Martínez-Lema, G.; Martínez, A.; Monrabal, F.; Monteiro, C. M. B.; Mora, F. J.; Moutinho, L. M.; Muñoz Vidal, J.; Musti, M.; Nebot-Guinot, M.; Novella, P.; Palmeiro, B.; Para, A.; Pérez, J.; Querol, M.; Repond, J.; Renner, J.; Riordan, S.; Ripoll, L.; Rodríguez, J.; Rogers, L.; Santos, F. P.; dos Santos, J. M. F.; 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.

    2018-03-01

    A new method to tag the barium daughter in the double beta decay of $^{136}$Xe is reported. Using the technique of single molecule fluorescent imaging (SMFI), individual barium dication (Ba$^{++}$) resolution at a transparent scanning surface has been demonstrated. A single-step photo-bleach confirms the single ion interpretation. Individual ions are localized with super-resolution ($\\sim$2~nm), and detected with a statistical significance of 12.9~$\\sigma$ over backgrounds. This lays the foundation for a new and potentially background-free neutrinoless double beta decay technology, based on SMFI coupled to high pressure xenon gas time projection chambers.

  18. Demonstration of Single-Barium-Ion Sensitivity for Neutrinoless Double-Beta Decay Using Single-Molecule Fluorescence Imaging

    Science.gov (United States)

    McDonald, A. D.; Jones, B. J. P.; Nygren, D. R.; Adams, C.; Álvarez, V.; Azevedo, C. D. R.; Benlloch-Rodríguez, J. M.; Borges, F. I. G. M.; Botas, A.; Cárcel, S.; Carrión, J. V.; Cebrián, S.; Conde, C. A. N.; Díaz, J.; Diesburg, M.; Escada, J.; Esteve, R.; Felkai, R.; Fernandes, L. M. P.; Ferrario, P.; Ferreira, A. L.; Freitas, E. D. C.; Goldschmidt, A.; Gómez-Cadenas, J. J.; González-Díaz, D.; Gutiérrez, R. M.; Guenette, R.; Hafidi, K.; Hauptman, J.; Henriques, C. A. O.; Hernandez, A. I.; Hernando Morata, J. A.; Herrero, V.; Johnston, S.; Labarga, L.; Laing, A.; Lebrun, P.; Liubarsky, I.; López-March, N.; Losada, M.; Martín-Albo, J.; Martínez-Lema, G.; Martínez, A.; Monrabal, F.; Monteiro, C. M. B.; Mora, F. J.; Moutinho, L. M.; Muñoz Vidal, J.; Musti, M.; Nebot-Guinot, M.; Novella, P.; Palmeiro, B.; Para, A.; Pérez, J.; Querol, M.; Repond, J.; Renner, J.; Riordan, S.; Ripoll, L.; Rodríguez, J.; Rogers, L.; Santos, F. P.; dos Santos, J. M. F.; 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.; NEXT Collaboration

    2018-03-01

    A new method to tag the barium daughter in the double-beta decay of Xe 136 is reported. Using the technique of single molecule fluorescent imaging (SMFI), individual barium dication (Ba++ ) resolution at a transparent scanning surface is demonstrated. A single-step photobleach confirms the single ion interpretation. Individual ions are localized with superresolution (˜2 nm ), and detected with a statistical significance of 12.9 σ over backgrounds. This lays the foundation for a new and potentially background-free neutrinoless double-beta decay technology, based on SMFI coupled to high pressure xenon gas time projection chambers.

  19. Results of a search for neutrinoless double-beta decay using the COBRA demonstrator

    Energy Technology Data Exchange (ETDEWEB)

    Quante, Thomas; Goessling, Claus; Kroeninger, Kevin [TU Dortmund, Exp. Physik IV, Dortmund (Germany)

    2016-07-01

    COBRA is an experiment aiming to search for neutrinoless double-beta-decay (0νββ-decay) using CdZnTe semiconductor detectors. The main focus is on {sup 116}Cd, with a Q-value of 2813.5 keV well above the highest dominant naturally occurring gamma lines. By measuring the half-life of the 0νββ-decay, it is possible to clarify the nature of the neutrino as either Dirac or Majorana particle and furthermore to determine its effective Majorana mass. The COBRA collaboration operates a demonstrator to search for these decays at the Laboratori Nazionali del Gran Sasso in Italy. The exposure of 234.7 kg d considered in this analysis was collected between September 2011 and February 2015. The analysis focuses on the decay of the nuclides {sup 114}Cd, {sup 128}Te, {sup 70}Zn, {sup 130}Te and {sup 116}Cd. A Bayesian analysis is performed to estimate the signal strength of 0νββ-decay.

  20. Experimental search for double beta decay of 100Mo

    International Nuclear Information System (INIS)

    Alston-Garnjost, M.; Dougherty, B.L.; Kenney, R.W.; Krivicich, J.M.; Tripp, R.D.; Nicholson, H.W.; Dieterle, B.D.; Leavitt, C.P.

    1986-01-01

    An experiment is proposed to search for double beta decay in 100 Mo using thin silicon solid state detectors. We expect to be sensitive to a half life limit of over 2 x 10 23 years for the neutrinoless mode and 2 x 10 20 years for the two-neutrino mode in one year's running. This is a substantial improvement in the measurement of the limits on electron neutrino mass and/or right-handed current admixtures over present 76 Ge experiments. 16 refs., 12 figs., 9 tabs

  1. Superallowed Beta Decay Studies at TRIUMF --- Nuclear Structure and Fundamental Symmetries

    Science.gov (United States)

    Zganjar, E. F.; Achtzehn, T.; Albers, D.; Andreoiu, C.; Andreyev, A. N.; Austin, R. A. E.; Ball, G. C.; Behr, J. A.; Biosvert, G. C.; Bricault, P.; Bishop, S.; Chakrawarthy, R. S.; Churchman, R.; Cross, D.; Cunningham, E.; D'Auria, J. M.; Dombsky, M.; Finlay, P.; Garrett, P. E.; Grinyer, G. F.; Hackman, G.; Hanemaayer, V.; Hardy, J. C.; Hodgson, D. F.; Hyland, B.; Iacob, V.; Klages, P.; Koopmans, K. A.; Kulp, W. D.; Lassen, J.; Lavoie, J. P.; Leslie, J. R.; Linder, T.; MacDonald, J. A.; Mak, H.-B.; Melconian, D.; Morton, A. C.; Ormand, W. E.; Osborne, C. J.; Pearson, C. J.; Pearson, M. R.; Phillips, A. A.; Piechaczek, A.; Ressler, J.; Sarazin, F.; Savard, G.; Schumaker, M. A.; Scraggs, H. C.; Svensson, C. E.; Valiente-Dobon, J. J.; Towner, I. S.; Waddington, J. C.; Walker, P. M.; Wendt, K.; Wood, J. L.

    2007-04-01

    Precision measurement of the beta -decay half-life, Q-value, and branching ratio between nuclear analog states of Jpi = 0+ and T=1 can provide critical and fundamental tests of the Standard Model's description of electroweak interactions. A program has been initiated at TRIUMF-ISAC to measure the ft values of these superallowed beta transitions. Two Tz = 0, A > 60 cases, 74Rb and 62Ga, are presented. These are particularly relevant because they can provide critical tests of the calculated nuclear structure and isospin-symmetry breaking corrections that are predicted to be larger for heavier nuclei, and because they demonstrate the advance in the experimental precision on ft at TRIUMF-ISAC from 0.26% for 74Rb in 2002 to 0.05% for 62Ga in 2006. The high precision world data on experimental ft and corrected Ft values are discussed and shown to be consistent with CVC at the 10-4 level, yielding an average Ft = 3073.70(74) s. This Ft leads to Vud = 0.9737(4) for the up-down element of the Standard Model's CKM matrix. With this value and the Particle Data Group's 2006 values for Vus and Vub, the unitarity condition for the CKM matrix is met. Additional measurements and calculations are needed, however, to reduce the uncertainties in that evaluation. That objective is the focus of the continuing program on superallowed-beta decay at TRIUMF-ISAC.

  2. Searches for exotic interactions in nuclear beta decay

    Energy Technology Data Exchange (ETDEWEB)

    Naviliat-Cuncic, O. [National Superconducting Cyclotron Laboratory and Department of Physics and Astronomy, Michigan State University, 640 S Shaw Lane, East Lansing MI 48824 (United States)

    2016-07-07

    This contribution presents current efforts in the search for exotic interactions in nuclear β decay using a calorimetric technique for the measurement of the β energy spectrum shape. We describe the criteria for the choice of sensitive candidates in Gamow-Teller transitions and present the status of measurements performed in {sup 6}He and {sup 20}F decay.

  3. Characterization of a ZnSe scintillating bolometer prototype for neutrinoless double beta decay search

    Directory of Open Access Journals (Sweden)

    Tenconi M.

    2014-01-01

    Full Text Available As proposed in the LUCIFER project, ZnSe crystals are attractive materials to realize scintillating bolometers aiming at the search for neutrinoless double beta decay of the promising isotope 82Se. However, the optimization of the ZnSe-based detectors is rather complex and requires a wide-range investigation of the crystal features: optical properties, crystalline quality, scintillation yields and bolometric behaviour. Samples tested up to now show problems in the reproducibility of crucial aspects of the detector performance. In this work, we present the results obtained with a scintillating bolometer operated aboveground at about 25 mK. The detector energy absorber was a single 1 cm3 ZnSe crystal. The good energy resolution of the heat channel (about 14 keV at 1460 keV and the excellent alpha/beta discrimination capability are very encouraging for a successful realization of the LUCIFER program. The bolometric measurements were completed by optical tests on the crystal (optical transmission and luminescence measurements down to 10 K and investigation of the crystalline structure. The work here described provides a set of parameters and procedures useful for a complete pre-characterization of ZnSe crystals in view of the realization of highly performing scintillating bolometers.

  4. LUCIFER, a potentially background-free approach to the search for neutrinoless double beta decay

    Energy Technology Data Exchange (ETDEWEB)

    Nones, C. [Centre de Spectrometrie Nucleaire et de Spectrometrie de Masse, Bat. 108 Orsay Campus - Orsay (France)

    2011-08-15

    LUCIFER (Low-background Underground Cryogenic Installation For Elusive Rates) is a new project for the study of neutrinoless Double Beta Decay, based on the technology of scintillating bolometers. These devices promise a very efficient rejection of the alpha background, opening the way to a virtual background-free experiment if candidates with a transition energy higher than 2615 keV are investigated. The baseline candidate for LUCIFER is {sup 82}Se. This isotope will be embedded in ZnSe crystals grown with enriched selenium and operated as scintillating bolometers in a low-radioactivity underground dilution refrigerator. In this paper, the LUCIFER concept will be introduced. The sensitivity and the very promising prospects related to this project will be discussed.

  5. Evaluation of the decay characteristics of isobars with A=95

    International Nuclear Information System (INIS)

    Grigor'yan, Yu.I.; Sokolovskij, L.L.; Chukreev, F.E.; Shurshikov, E.N.

    1978-06-01

    Energies and intensities of the beta transitions, gamma photons and conversion electrons accompanying beta decay and electron capture, internal conversion coefficients, energy levels and lifetimes of the ground and excited states of isobars with A=95 are evaluated and presented in tables and diagrams

  6. Hamiltonian Markov Chain Monte Carlo Methods for the CUORE Neutrinoless Double Beta Decay Sensitivity

    Science.gov (United States)

    Graham, Eleanor; Cuore Collaboration

    2017-09-01

    The CUORE experiment is a large-scale bolometric detector seeking to observe the never-before-seen process of neutrinoless double beta decay. Predictions for CUORE's sensitivity to neutrinoless double beta decay allow for an understanding of the half-life ranges that the detector can probe, and also to evaluate the relative importance of different detector parameters. Currently, CUORE uses a Bayesian analysis based in BAT, which uses Metropolis-Hastings Markov Chain Monte Carlo, for its sensitivity studies. My work evaluates the viability and potential improvements of switching the Bayesian analysis to Hamiltonian Monte Carlo, realized through the program Stan and its Morpho interface. I demonstrate that the BAT study can be successfully recreated in Stan, and perform a detailed comparison between the results and computation times of the two methods.

  7. A zero-to-few-hundred eV proton beam for calibrations of neutron beta decay experiments

    CERN Document Server

    Naab, F; Zech, W; García, A; Mumm, P

    2002-01-01

    We have constructed a system using a duoplasmatron source to produce a beam of low-energy (0 - few hundred eV) protons with the principal goal of testing and calibrating detectors used to detect protons from neutron beta decay. The system is stable and produces beams by simply turning on the associated power supplies without the need of careful tuning. As an example we show data from calibration of a surface barrier detector in the emiT apparatus. Protons from the system were scattered from an Al target and used to calibrate detectors in the emiT apparatus.

  8. Decays of 22Al and 26P: discovery of beta-delayed two-proton radioactivity

    International Nuclear Information System (INIS)

    Cable, M.D.

    1983-02-01

    A helium-jet system and the 24 Mg( 3 He,p4n) 22 Al and 28 Si( 3 He,p4n) 26 P reactions have been used to discover the only known odd-odd, T/sub Z/ = -2 nuclides, 22 Al(t/sub 1/2/ approx. 70ms) and 26 P(t/sub 1/2/ approx. 20 ms). Observations of beta-delayed protons from each isotope (laboratory energies 7.839 +- 0.015 MeV and 8.149 +- 0.021 MeV for 22 Al and 7.269 +- 0.015 MeV and 6.827 +- 0.050 MeV for 26 P) established the existence of these nuclides and provided a measurement of the mass excesses of the lowest T = 2 states in their beta decay daughters, 22 Mg and 26 Si (13.650 +- 0.015 MeV and 5.936 +- 0.015 MeV, respectively). Measurement of these masses confirmed that these T = 2 states were unbound to two-proton emission as had been predicted theoretically

  9. Radioactive decays at limits of nuclear stability

    DEFF Research Database (Denmark)

    Pfützner, M.; Karny, M.; Grigorenko, L. V.

    2012-01-01

    , and their relative probabilities. When approaching limits of nuclear stability, new decay modes set in. First, beta decays are accompanied by emission of nucleons from highly excited states of daughter nuclei. Second, when the nucleon separation energy becomes negative, nucleons start being emitted from the ground...

  10. Calibration of radionuclides with decay trough beta emission or electron capture by liquid scintillation technique

    International Nuclear Information System (INIS)

    Loureiro, Jamir dos Santos

    2000-02-01

    In this work is reported a methodology a methodology for pure beta and electron capture radionuclides standardization, suing liquid scintillation technique. In this sense the CIEMAT/NIST method, recently utilized by international laboratories, was implemented and the lack in the Laboratorio Nacional das Radiacoes Ionizantes - LNMRI, of the Comissao Nacional de Energia Nuclear - CNEN, for adequate methodology to standardize this kind if radionuclides was filled, fact that was not present with alpha and gamma radionuclides. The implementation procedure evaluation was provided by concentration activity determination of the following radionuclides: 14 C and 90 Sr, pure beta emitters; 55 Fe, electron capture decay; 204 Tl, electron capture and beta decay and 60 Co, beta-gamma emitter. In this way, a careful analysis of the implementation procedure with these radionuclides types, ranging on a broad energy spectral, was possible. To check the calibration results, intercomparisons among our measurements of these radionuclides and the reference values of the CIEMAT/Spain laboratory were provided. To check the calibration results, intercomparisons among our measurements of these radionuclides and the reference values of the CIEMAT/Spain laboratory were provided. Besides this intercomparisons, one was provided with a 204 Tl solution, utilized in the international comparison recently promoted by BIPM, and another one with a 60 C solution calibrated in LNMRI/CNEN previously by a relative calibration system, with a well type pressurized ionization chamber, and an absolute beta-gamma coincidence system, with a pill-box type proportional counter 4 π geometry, coupled with a scintillator system with a sodium iodide cristal of 4x4 inches. The comparisons among LNMRI/CNEN results and the reference values, showed a small deviation of 1,32% for 14 C, 0,40% for 60 Co, 1,12% for 55 Fe, 0,10% for 90 Sr and 0,73% for 204 Tl. For the BIPM solution the deviation was 0,46% and for 60 Co

  11. Beta decay and strength distributions

    International Nuclear Information System (INIS)

    Hardy, J.C.

    1980-01-01

    With the increasing accessibility of nuclei far from stability, experimenters find themselves faced more and more often with complex β-decay schemes: nuclei with over 5 MeV of β-decay energy, exhibiting hundreds and perhaps thousands of transitions. A detailed level-by-level exposition of such schemes - for example, by studying β-delayed γ-rays - is at best prohibitively time consuming, and at worst actually impossible with current techniques. Furthermore, even if reliable schemes are obtained experimentally, their confrontation with theory is severely limited by the absence of theories sufficiently complete to account for such complex spectra. At best, it is the details of the first few excited states and the general features of the rest that are useful for comparison. From both points of view, experimental and theoretical, there is strong motivation to find a broader perspective, emphasizing these general features without being overwhelmed by a proliferation of detail

  12. Search for the Neutrino Less Double Beta Decay

    Energy Technology Data Exchange (ETDEWEB)

    Efremenko, Yuri [Univ. of Tennessee, Knoxville, TN (United States). Dept. of Physics and Astronomy

    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

  13. Neutrino-Less Double Beta Decay - Experimentum Crucis of Neutrino Physics

    International Nuclear Information System (INIS)

    Sujkowski, Z.

    2003-01-01

    The presently most wanted information on neutrino properties concerns their mass values and their transformation properties under charge conjugation. The recent oscillation experiments prove that at least one of the three neutrino species has a non-vanishing rest mass and that the lepton flavour is not conserved. These findings have to be supplemented by data from phenomena of different kind in order to deduce the information needed. The most promising method proposed thus far to determine Majorana neutrino mass and thus to answer the two leading questions is to observe the neutrino-less double beta decay and to measure its rate. The physics of this process is discussed and the on-going and planned experimental search is reviewed. This search concentrates on the 0 + →0 + ground-to-ground state decay of β - β - emitters using calorimetric or β - -β - coincidence tracking techniques. The β + β + or β + EC decays are usually considered as less favourable because of longer half-lives, even though they offer some advantages in combating the background. The recent proposition of measuring the monoenergetic photon spectra accompanying the radiative neutrino-less double electron capture decay is discussed. The experimental advantages of this technique may off-set the generally longer life-times expected. (author)

  14. EDISTR: a computer program to obtain a nuclear decay data base for radiation dosimetry

    International Nuclear Information System (INIS)

    Dillman, L.T.

    1980-01-01

    This report provides documentation for the computer program EDISTR. EDISTR uses basic radioactive decay data from the Evaluated Nuclear Structure Data File developed and maintained by the Nuclear Data Project at the Oak Ridge National Laboratory as input, and calculates the mean energies and absolute intensities of all principal radiations associated with the radioactive decay of a nuclide. The program is intended to provide a physical data base for internal dosimetry calculations. The principal calculations performed by EDISTR are the determination of (1) the average energy of beta particles in a beta transition, (2) the beta spectrum as function of energy, (3) the energies and intensities of x-rays and Auger electrons generated by radioactive decay processes, (4) the bremsstrahlung spectra accompanying beta decay and monoenergetic Auger and internal conversion electrons, and (5) the radiations accompanying spontaneous fission. This report discusses the theoretical and empirical methods used in EDISTR and also practical aspects of the computer implementation of the theory. Detailed instructions for preparing input data for the computer program are included, along with examples and discussion of the output data generated by EDISTR

  15. Fast-timing studies of nuclei below $^{68}$Ni populated in the $\\beta$-decay of Mn isotopes

    CERN Multimedia

    Jokinen, A; Simpson, G S; Garcia borge, M J; Koester, U H; Georgiev, G P; Fraile prieto, L M; Aprahamian, A

    2008-01-01

    We intend to investigate structure of nuclei populated in the $\\beta$-decay of Mn isotopes via the ATD $\\beta\\gamma\\gamma$(t) technique. With this method we will measure dynamic moments in Fe isotopes and their daughters in order to characterize the role of particle-hole excitation across the ${N}$=40 sub-shell closure and the development of collectivity.

  16. Beta-Delayed Neutron Spectroscopy of 72Co with VANDLE

    Science.gov (United States)

    Keeler, Andrew; Grzywacz, Robert; King, Thomas; Taylor, Steven; Paulauskas, Stanley; Zachary, Christopher; Vandle Collaboration

    2017-09-01

    Measurements of simple, closed-shell isotopes far from stability provide important benchmarks for nuclear models and are a key constraint in r-process calculations. In particular, r-process models are sensitive to beta decay lifetimes and branching ratios of these neutron-rich isotopes. In this experiment, the Versatile Array of Neutron Detectors at Low Energy (VANDLE) was used to observe decays of nuclei produced by the fragmentation of 82Se at the National Superconducting Cyclotron Laboratory (NSCL). The neutron and gamma emissions of 72Co were measured to map the beta strength distribution (S_beta) above the neutron separation energy and infer the size of the Z = 28 shell gap in the 78Ni region. An implantation detector made of a radiation-hardened, inorganic scintillator was used to correlate implanted ions with beta decays as well as provide a start signal for the neutron Time of Flight measurement. Funded by the National Nuclear Security Administration under the Stewardship Science Academic Alliances program through DOE Award No. DE-NA0002132 and by the Office of Nuclear Physics, U.S. Department of Energy under Awards No. DE-FG02-96ER40983 (UTK).

  17. Beta-spectroscopy of long lived nuclides with a PIPS detector-setup

    Directory of Open Access Journals (Sweden)

    Domula Alexander R.

    2017-01-01

    Full Text Available Several applications in modern nuclear physics, research and engineering are limited by a lack of precise knowledge in spectral shape data for beta-decays. Specifically the interest aims to study spectral data for forbidden decays with respectively long half-lives, which is one of the central activities of our group. For the investigation of those rare beta-decays the group operates a setup of six PIPS detectors in a vacuum chamber built out of low-radioactivity materials. In the long term the setup will be used as low-background-detector for the investigation of rare beta-decays. In order to reduce the measuring-background a muon veto was installed. The characterization of the setup in the energy-range from 20..1000 keV using conversion-electrons is described. A set of useful calibration-nuclides was established to determine energy calibration and efficiencies.

  18. Decay spectroscopy for nuclear astrophysics: β- and β-delayed proton decay

    Science.gov (United States)

    Trache, L.; Banu, A.; Hardy, J. C.; Iacob, V. E.; McCleskey, M.; Roeder, B. T.; Simmons, E.; Spiridon, A.; Tribble, R. E.; Saastamoinen, A.; Jokinen, A.; Äysto, J.; Davinson, T.; Lotay, G.; Woods, P. J.; Pollacco, E.

    2012-02-01

    In several radiative proton capture reactions important in novae and XRBs, the resonant parts play the capital role. We use decay spectroscopy techniques to find these resonances and study their properties. We have developed techniques to measure beta- and beta-delayed proton decay of sd-shell, proton-rich nuclei produced and separated with the MARS recoil spectrometer of Texas A&M University. The short-lived radioactive species are produced in-flight, separated, then slowed down (from about 40 MeV/u) and implanted in the middle of very thin Si detectors. This allows us to measure protons with energies as low as 200 keV from nuclei with lifetimes of 100 ms or less. At the same time we measure gamma-rays up to 8 MeV with high resolution HPGe detectors. We have studied the decay of 23Al, 27P, 31Cl, all important for understanding explosive H-burning in novae. The technique has shown a remarkable selectivity to beta-delayed charged-particle emission and works even at radioactive beam rates of a few pps. The states populated are resonances for the radiative proton capture reactions 22Na(p,γ)23Mg (crucial for the depletion of 22Na in novae), 26mAl(p,γ)27Si and 30P(p,γ)31S (bottleneck in novae and XRB burning), respectively. Lastly, results with a new detector that allowed us to measure down to about 80 keV proton energy are announced.

  19. Decay spectroscopy for nuclear astrophysics: β- and β-delayed proton decay

    International Nuclear Information System (INIS)

    Trache, L; Banu, A; Hardy, J C; Iacob, V E; McCleskey, M; Roeder, B T; Simmons, E; Spiridon, A; Tribble, R E; Saastamoinen, A; Jokinen, A; Äysto, J; Davinson, T; Lotay, G; Woods, P J; Pollacco, E

    2012-01-01

    In several radiative proton capture reactions important in novae and XRBs, the resonant parts play the capital role. We use decay spectroscopy techniques to find these resonances and study their properties. We have developed techniques to measure beta- and beta-delayed proton decay of sd-shell, proton-rich nuclei produced and separated with the MARS recoil spectrometer of Texas A and M University. The short-lived radioactive species are produced in-flight, separated, then slowed down (from about 40 MeV/u) and implanted in the middle of very thin Si detectors. This allows us to measure protons with energies as low as 200 keV from nuclei with lifetimes of 100 ms or less. At the same time we measure gamma-rays up to 8 MeV with high resolution HPGe detectors. We have studied the decay of 23 Al, 27 P, 31 Cl, all important for understanding explosive H-burning in novae. The technique has shown a remarkable selectivity to beta-delayed charged-particle emission and works even at radioactive beam rates of a few pps. The states populated are resonances for the radiative proton capture reactions 22 Na(p,γ) 23 Mg (crucial for the depletion of 22 Na in novae), 26m Al(p,γ) 27 Si and 30 P(p,γ) 31 S (bottleneck in novae and XRB burning), respectively. Lastly, results with a new detector that allowed us to measure down to about 80 keV proton energy are announced.

  20. Theory of neutrinoless double beta decay

    CERN Document Server

    Vergados, J.D.; Simkovic, F.

    2012-01-01

    Neutrinoless double beta decay, which is a very old and yet elusive process, is reviewed. Its observation will signal that lepton number is not conserved and 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 have to be overcome involving particle, nuclear and experimental physics. Nuclear physics is important for extracting the 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 recently been developed, which give confidence that the needed nuclear matrix elements can be reliably calculated. From an experimental point of view it is challenging, since the life times are long and one has to fight against formidable backgrounds. If a signal is found, it will be a tremendous accomplishment. Then, of course, the real task is going ...

  1. The γ activity from 11Li beta decay

    International Nuclear Information System (INIS)

    Detraz, C.; Guillemaud, D.; Langevin, M.; Naulin, F.; Epherre, M.; Klapisch, R.; Saint-Simon, M. de; Thibault, C.; Touchard, F.

    1980-01-01

    The energies and absolute intensities of the γ-rays from the β-decay of 11 Li are measured. There is no sizable β branch to the 11 Be ground state. Only (5.2+-1.4)% of the β-decay strength does not lead to β-delayed particle emission. New β-delayed neutron branches to excited states of 10 Be are observed and the total delayed neutron emission probability is deduced

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

    Energy Technology Data Exchange (ETDEWEB)

    Povinec, Pavel P.

    2017-02-11

    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 {sup 82}Se. The half-life sensitivity of the Demonstrator is expected to be >6.5·10{sup 24} 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 {sup 82}Se source should reach an effective Majorana neutrino mass sensitivity of |0.04−0.1| eV, and a half-life limit 1·10{sup 26} y. - Highlights: • SuperNEMO detector for 2β0ν-decay of {sup 82}Se should reach half-life limit of 10{sup 26} y. • Radiopurity of the SuperNEMO internal detector parts was checked down to 0.1 mBq/kg. • Reference material of glass pellets was developed for underground γ-spectrometry.

  3. Alpha decay and various problems related to it

    International Nuclear Information System (INIS)

    Katori, Kenji

    1992-01-01

    On the proton-excessive nucleus side of lanthanide and actinide, alpha decay is the main decay mode. In lanthanide region, alpha decay has been measured to the drip line for most even-even nuclei. In the measurement of alpha decay, emitted energy and life are measured, but the measurement of converted alpha width remains in the limited range. In order to obtain the converted alpha width of high accuracy, the nucleus formation in larger quantity on the drip line and the simultaneous measurement with a multiple detector system including gamma ray and beta ray are required. In this paper, three topics related to alpha cluster and alpha decay and the problems that confront at present are discussed. The continuation to exist of alpha cluster structure to heavy nuclei, the analysis of lanthanide nucleus region by the alpha giant resonance model, and the new data on the alpha ray decaying from the mass of 175, 176 and 177 are reported. In lanthanide nucleus region, remarkable interference was not observed between beta-2 and beta-3 modes in the converted alpha width measured between the ground states. The present problems in alpha decay are enumerated. (K.I.)

  4. Beta-decay study of T{sub z}=-2 proton-rich nucleus {sup 24}Si

    Energy Technology Data Exchange (ETDEWEB)

    Ichikawa, Y.; Iwasaki, H.; Nakao, T.; Ong, H.J.; Onishi, T.K.; Suzuki, D.; Suzuki, H.; Suzuki, M.K. [University of Tokyo, Department of Physics, Tokyo (Japan); Kubo, T.; Aoi, N.; Fukuda, N.; Motobayashi, T.; Yamada, K.N.; Sakurai, H. [RIKEN, RIKEN Nishina Center, Saitama (Japan); Banerjee, V.; Chakrabarti, A. [Variable Energy Cyclotron Centre, Kolkata (India); Kubono, S.; Yamaguchi, H. [University of Tokyo, Center for Nuclear Study, Tokyo (Japan); Nakabayashi, T.; Nakamura, T.; Okumura, T. [Tokyo Institute of Technology, Department of Physics, Tokyo (Japan); Teranishi, T. [Kyushu University, Department of Physics, Fukuoka (Japan)

    2009-12-15

    {beta} -decay spectroscopy on a T{sub z}=-2 proton-rich nucleus {sup 24}Si was performed. The decay scheme of {sup 24}Si was reconstructed by the {beta} -delayed {gamma} -ray and proton measurements. Two {beta} branches to the bound 1{sub 1}{sup +} and 1{sub 2}{sup +} states in {sup 24}Al were observed for the first time. The observation of the allowed transition firmly established the spin-parity assignment for the 1{sub 2}{sup +} states. The branching ratios to the 1{sub 1}{sup +} and 1{sub 2}{sup +} states were determined to be 31(4)% and 23.9(15)%, respectively. The branching ratios to three unbound states in {sup 24}Al including a new level at 6.735MeV were also determined for the first time. The level structure of {sup 24}Al was compared with its mirror nucleus {sup 24}Na. The Thomas-Ehrman shift on the 1{sub 2}{sup +} state indicates s -wave dominance in the state as well as a characteristic behavior of the weakly bound s-wave proton in {sup 24}Al. (orig.)

  5. FITPULS: a code for obtaining analytic fits to aggregate fission-product decay-energy spectra

    International Nuclear Information System (INIS)

    LaBauve, R.J.; George, D.C.; England, T.R.

    1980-03-01

    The operation and input to the FITPULS code, recently updated to utilize interactive graphics, are described. The code is designed to retrieve data from a library containing aggregate fine-group spectra (150 energy groups) from fission products, collapse the data to few groups (up to 25), and fit the resulting spectra along the cooling time axis with a linear combination of exponential functions. Also given in this report are useful results for aggregate gamma and beta spectra from the decay of fission products released from 235 U irradiated with a pulse (10 -4 s irradiation time) of thermal neutrons. These fits are given in 22 energy groups that are the first 22 groups of the LASL 25-group decay-energy group structure, and the data are expressed both as MeV per fission second and particles per fission second; these pulse functions are readily folded into finite fission histories. 65 figures, 11 tables

  6. Measurement of the proton recoil spectrum in neutron beta decay with the spectrometer aSPECT. Study of systematic effects

    Energy Technology Data Exchange (ETDEWEB)

    Konrad, Gertrud Emilie

    2012-01-24

    Free neutron decay, n{yields}pe anti {nu}{sub e}, is the simplest nuclear beta decay, well described as a purely left-handed, vector minus axial-vector interaction within the framework of the Standard Model (SM) of elementary particles and fields. Due to its highly precise theoretical description, neutron beta decay data can be used to test certain extensions to the SM. Possible extensions require, e.g., new symmetry concepts like left-right symmetry, new particles, leptoquarks, supersymmetry, or the like. Precision measurements of observables in neutron beta decay address important open questions of particle physics and cosmology, and are generally complementary to direct searches for new physics beyond the SM in high-energy physics. In this doctoral thesis, a measurement of the proton recoil spectrum with the neutron decay spectrometer aSPECT is described. From the proton spectrum the antineutrinoelectron angular correlation coefficient a can be derived. In our first beam time at the Forschungs-Neutronenquelle Heinz Maier-Leibnitz in Munich, Germany (2005-2006), background instabilities due to particle trapping and the electronic noise level of the proton detector prevented us from presenting a new value for a. In the latest beam time at the Institut Laue-Langevin (ILL) in Grenoble, France (2007-2008), the trapped particle background has been reduced sufficiently and the electronic noise problem has essentially been solved. For the first time, a silicon drift detector was used. As a result of the data analysis, we identified and fixed a problem in the detector electronics which caused a significant systematic error. The target figure of the latest beam time was a new value for a with a total relative error well below the present literature value of 4 %. A statistical accuracy of about 1.4% was reached, but we could only set upper limits on the correction of the problem in the detector electronics, which are too high to determine a meaningful result. The present

  7. Measurement of the proton recoil spectrum in neutron beta decay with the spectrometer aSPECT. Study of systematic effects

    International Nuclear Information System (INIS)

    Konrad, Gertrud Emilie

    2012-01-01

    Free neutron decay, n→pe anti ν e , is the simplest nuclear beta decay, well described as a purely left-handed, vector minus axial-vector interaction within the framework of the Standard Model (SM) of elementary particles and fields. Due to its highly precise theoretical description, neutron beta decay data can be used to test certain extensions to the SM. Possible extensions require, e.g., new symmetry concepts like left-right symmetry, new particles, leptoquarks, supersymmetry, or the like. Precision measurements of observables in neutron beta decay address important open questions of particle physics and cosmology, and are generally complementary to direct searches for new physics beyond the SM in high-energy physics. In this doctoral thesis, a measurement of the proton recoil spectrum with the neutron decay spectrometer aSPECT is described. From the proton spectrum the antineutrinoelectron angular correlation coefficient a can be derived. In our first beam time at the Forschungs-Neutronenquelle Heinz Maier-Leibnitz in Munich, Germany (2005-2006), background instabilities due to particle trapping and the electronic noise level of the proton detector prevented us from presenting a new value for a. In the latest beam time at the Institut Laue-Langevin (ILL) in Grenoble, France (2007-2008), the trapped particle background has been reduced sufficiently and the electronic noise problem has essentially been solved. For the first time, a silicon drift detector was used. As a result of the data analysis, we identified and fixed a problem in the detector electronics which caused a significant systematic error. The target figure of the latest beam time was a new value for a with a total relative error well below the present literature value of 4 %. A statistical accuracy of about 1.4% was reached, but we could only set upper limits on the correction of the problem in the detector electronics, which are too high to determine a meaningful result. The present doctoral

  8. Identification of shell-model states in $^{135}$Sb populated via $\\beta^{-}$ decay of $^{135}$Sn

    CERN Document Server

    Shergur, J; Brown, B A; Cederkäll, J; Dillmann, I; Fraile-Prieto, L M; Hoff, P; Joinet, A; Köster, U; Kratz, K L; Pfeiffer, B; Walters, W B; Wöhr, A

    2005-01-01

    The $\\beta$- decay of $^{135}$Sn was studied at CERN/ISOLDE using a resonance ionization laser ion source and mass separator to achieve elemental and mass selectivity, respectively. $\\gamma$-ray singles and $\\gamma\\gamma$ coincidence spectra were collected as a function of time with the laser on and with the laser off. These data were used to establish the positions of new levels in $^{135}$Sb, including new low-spin states at 440 and 798 keV, which are given tentative spin and parity assignments of 3/2$^{+}$ and 9/2$^{+}$, respectively. The observed levels of $^{135}$Sb are compared with shell-model calculations using different single-particle energies and different interactions.

  9. Beta decay of 30Na: experiment and theory

    International Nuclear Information System (INIS)

    Baumann, P.; Dessagne, P.; Huck, A.; Klotz, A.; Knipper, A.; Miehe, C.; Ramdane, M.; Walter, G.; Marguier, G.; Poves, A.

    1988-01-01

    The 30 Na β decay was studied on-line by means of mass-separation techniques. Gamma-ray, gamma-gamma, neutron-gamma spectra, neutron time-of-flight singles and γ-coincidence measurements, were registered. High-energy neutron branches (E n >2 MeV) were found complementing previouly reported data. A 30 Na β-decay scheme to 30 Mg bound and unbound states is established. The distribution of the transition strength as a function of the excitation energy for particle-unbound levels in 30 Mg is compared to shell-model calculations performed in the 0-12 MeV excitation energy range. An overall renormalization yields a B(GT) quenching factor of 0.28 substantially lower than generally observed in this mass region. Three levels in 29 Mg which are strongly populated via the 1n-channel are related to negative parity intruder states

  10. Decays of 143La and 145Ce using KUR-ISOL

    International Nuclear Information System (INIS)

    Ukon, Hiroe; Shibata, Michihiro; Kawade, Kiyoshi; Yamamoto, Hiroshi; Katoh, Toshiro; Kawase, Yoichi; Okano, Kotoyuki; Ruan, J.Z.

    1987-01-01

    Accurate measurements of beta- and gamma-rays resulting from the decay of 143 La and 145 Ce are made with KUR-ISOL to develop their decay diagram. First, gamma-singles spectrometry is performed to determine the energy and intensity of gamma-rays resulting from the decay of 143 La and 145 Ce. About 30 and 7 peaks are newly identified for 143 La and 145 Ce, respectively, in their gamma-ray spectra. Another gamma-singles spectrometry is carried out using 60 cm 3 Ge(Li) and LEPS detectors to determine 620 keV gamma-ray emission rate in the decay of 143 La. The emission rate is calculated at 4.23 and 4.62 percent from measurements made with Ge(Li) and LEPS, respectively. Gamma-gamma coincidence spectrometry is performed using a 60 cm 3 Ge(Li)-142 cm 3 Ge(Li) or a 60 cm 3 Ge(Li)-LEPS detector. LEPS is then applied to beta-singles spectrometry to determine the maximum energy of the gamma-rays from 143 La and 145 Ce within an error of about 20 keV. The beta-ray end point is determined from the measurements. Decay diagrams of 143 La and 145 Ce are constructed based on these results. The intensity and multipolarity of 18.9, 23.4 and 42.3 keV gamma-rays in the decay of 143 La are determined. Energy and intensity of gamma-rays of 2.8 MeV or above are also determined for 143 La. Three low energy levels of 145 Ce is examined in comparison to the decay diagram of 143 La. 143 Ce is found to have an energy level structure similar to that of other nuclides of N = 85. (Nogami, K.)

  11. Present status of radiochemical double beta decay study (238U)

    International Nuclear Information System (INIS)

    Madic, C.; Maillard, C.; Chevallier, A.; Chevallier, J.; Escoubes, B.; Schulz, N.; Sens, J.C.

    1989-01-01

    A sensitive experiment has been designed that will be able to measure an assumed half-life of 1.9x10 22 yr. This double beta corresponds to the activity of 27000 238 Pu nuclei formed during a year, in a 200 m deep mine, from 300 kg of 238 U, giving 210 alpha decays per year. Plutonium 238 et 239 will be determined by alpha spectroscopy after extraction chromatography. Experimental studies were undertaken to select the best conditions for running the extraction chromatography cycles

  12. Alpha and beta detection and spectrometry

    International Nuclear Information System (INIS)

    Saro, S.

    1984-01-01

    The theory of alpha and beta radioactive decay, the interaction of alpha and beta particles with matter, and their detection and spectrometry are dealt with in seven chapters: 1. Alpha transformation of atomic nuclei; 2. Basic properties of detectors and statistics of detection; 3. Alpha detectors and spectrometers; 4. Applications of alpha detection and spectrometry; 5. Beta transformation of atomic nuclei; 6. Beta particle detectors and spectrometers; 7. Detection of low energy beta particles. Chapter 8 is devoted to sampling and preparation of samples for radiometry. (E.F.)

  13. Results on neutrinoless double beta decay of 76Ge from GERDA Phase I

    Science.gov (United States)

    Palioselitis, Dimitrios; GERDA Collaboration

    2015-05-01

    The Germanium Detector Array (GERDA) experiment is searching for the neutrinoless double beta (0νββ) decay of 76Ge by operating bare germanium diodes in liquid argon. GERDA is located at the Gran Sasso National Laboratory (LNGS) in Italy. During Phase I, a total exposure of 21.6 kg yrand a background index of 0.01 cts/(keVkg yr) were reached. No signal was observed and a lower limit of T0ν1/2 > 2.1 · 1025 yr(90% C.L.) is derived for the half life of the 0νββ decay of 76Ge.

  14. Beta-decay half-lives and level ordering of sup 1 sup 0 sup 2 sup m sup , sup g Rh

    CERN Document Server

    Shibata, M; Itoh, S; Itoh, S; Yamamoto, H; Kawade, K; Kasugai, Y; Ikeda, Y

    1998-01-01

    Beta-decay half-lives of the ground state and an isomer of sup 1 sup 0 sup 2 Rh have been determined 207.3(17) d and 3.742(10) y, respectively, by gamma-ray decay curves following each beta-decay. It has been found that a state (2 sup -) which has a shorter half-life (207.3 d) is the ground state from the result that the half-life of the 41.9 keV isomeric gamma-transition was equal to 3.742 y. It has also been confirmed that the 41.9 keV transition is certainly an isomeric transition with X-gamma coincidence measurement.

  15. The NEXT-100 experiment for neutrinoless double beta decay searches (Conceptual Design Report)

    CERN Document Server

    Álvarez, V; Batallé, M; Bayarri, J; Borges, F I G; Cárcel, S; Carmona, J M; Castel, J; Catalá, J M; Cebrián, S; Cervera-Villanueva, A; Chan, D; Conde, C A N; Dafni, T; Dias, T H V T; Díaz, J; Esteve, R; Evtoukhovitch, P; Fernandes, L M P; Ferrario, P; Ferrer-Ribas, E; Ferreira, A L; Freitas, E D C; Gil, A; Giomataris, I; Goldschmidt, A; Gómez, E; Gómez, H; Gómez-Cadenas, J J; Gónzález, K; Gutiérrez, R M; Hernando-Morata, J A; Herrera, D C; Herrero, V; Iguaz, F; Irastorza, I G; Kalinnikov, V; Kustov, A; Liubarsky, I; Lopes, J A M; Lorca, D; Losada, M; Luzón, G; Martín-Albo, J; Méndez, A; Miller, T; Moisenko, A; Mols, J P; Monrabal, F; Monteiro, C M B; Monzó, J M; Mora, F J; Muñoz-Vidal, J; da Luz, H Natal; Navarro, G; Nebot, M; Nygren, D; Oliveira, C A B; Palma, R; Pérez-Aparicio, J L; Renner, J; Ripoll, L; Rodríguez, A; Rodríguez, J; Santos, F P; Santos, J M F dos; Seguí, L; Serra, L; Sofka, C; Sorel, M; Spieler, H; Toledo, J F; Tomás, A; Tsamalaidze, Z; Vázquez, D; Velicheva, E; Veloso, J F C A; Villar, J A; Webb, R; Weber, T; White, J; Yahlali, N

    2011-01-01

    We propose an EASY (Electroluminescent ApparatuS of high Yield) and SOFT (Separated Optimized FuncTion) time-projection chamber for the NEXT experiment, that will search for neutrinoless double beta decay (bb0nu) in Xe-136. Our experiment must be competitive with the new generation of bb0nu searches already in operation or in construction. This requires a detector with very good energy resolution (<1%), very low background con- tamination (1E-4 counts/(keV \\bullet kg \\bullet y)) and large target mass. In addition, it needs to be operational as soon as possible. The design described here optimizes energy resolution thanks to the use of proportional electroluminescent amplification (EL); it is compact, as the Xe gas is under high pressure; and it allows the measurement of the topological signature of the event to further reduce the background contamination. The SOFT design uses different sensors for tracking and calorimetry. We propose the use of SiPMs (MPPCs) coated with a suitable wavelength shifter for th...

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

    Energy Technology Data Exchange (ETDEWEB)

    Bellini, F. [Dipartimento di Fisica, Sapienza Universita di Roma, Roma I-00185 (Italy) and INFN - Sezione di Roma, Roma I-00185 (Italy)

    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.

  17. Beta-decay half-lives at the N=28 shell closure

    Energy Technology Data Exchange (ETDEWEB)

    Grevy, S.; Angelique, J.C.; Baumann, P.; Borcea, C.; Buta, A.; Canchel, G.; Catford, W.N.; Courtin, S.; Daugas, J.M.; Oliveira, F. de; Dessagne, P.; Dlouhy, Z.; Knipper, A.; Kratz, K.L.; Lecolley, F.R.; Lecouey, J.L.; Lehrsenneau, G.; Lewitowicz, M.; Lienard, E.; Lukyanov, S.; Marechal, F.; Miehe, C.; Mrazek, J.; Negoita, F.; Orr, N.A.; Pantelica, D.; Penionzhkevich, Y.; Peter, J.; Pfeiffer, B.; Pietri, S.; Poirier, E.; Sorlin, O.; Stanoiu, M.; Stefan, I.; Stodel, C.; Timis, C

    2004-08-05

    Measurements of the beta-decay half-lives of neutron-rich nuclei (Mg-Ar) in the vicinity of the N=28 shell closure are reported. Some 22 half-lives have been determined, 12 of which for the first time. Particular emphasis is placed on the results for the Si isotopes, the half-lives of which have been extended from N=25 to 28. Comparison with QRPA calculations suggests that {sup 42}Si is strongly deformed. This is discussed in the light of a possible weakening of the spin-orbit potential.

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

    Science.gov (United States)

    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.

  19. Neutrinoless double-beta decay in left-right symmetric models

    International Nuclear Information System (INIS)

    Picciotto, C.E.; Zahir, M.S.

    1982-06-01

    Neutrinoless double-beta decay is calculated via doubly charged Higgs, which occur naturally in left-right symmetric models. We find that the comparison with known half-lives yields values of phenomenological parameters which are compatible with earlier analyses of neutral current data. In particular, we obtain a right-handed gauge-boson mass lower bound of the order of 240 GeV. Using this result and expressions for neutrino masses derived in a parity non-conserving left-right symmetric model, we obtain msub(νsub(e)) < 1.5 eV, msub(νsub(μ)) < 0.05 MeV and msub(νsub(tau)) < 18 MeV

  20. From beta-relaxation to alpha-decay: Atomistic picture from molecular dynamics simulations for glass-forming Ni0.5Zr0.5 melt

    Energy Technology Data Exchange (ETDEWEB)

    Teichler, Helmar [Inst. Materialphysik, Univ Goettingen (Germany)

    2013-07-01

    In glass-forming melts the decay of structural fluctuation shows the well known transition from beta-relaxation (von-Schweidler law with exponent b) to alpha-decay (KWW law with exponent beta). Here we present results from molecular dynamics simulations for a metallic glass forming Ni0.5Zr0.5 model aimed at giving an understanding of this transition on the atomistic scale. At the considered temperature below mode coupling Tc, the dynamics of the system can be interpreted by residence of the particles in their neighbour cages and escape from the cages as rare processes. Our analysis yields that the fraction of residing particles is characterized by a hierarchical law in time, with von-Schweidler b explicitly related to the exponent of this law. In the alpha-decay regime the stretching exponent reflects, in addition, floating of the cages due to strain effects of escaped particles. Accordingly, the change from beta-relaxation to alpha-decay indicates the transition from low to large fraction of escaped particles.

  1. Penning trap mass spectrometry Q-value determinations for highly forbidden β-decays

    Science.gov (United States)

    Sandler, Rachel; Bollen, Georg; Eibach, Martin; Gamage, Nadeesha; Gulyuz, Kerim; Hamaker, Alec; Izzo, Chris; Kandegedara, Rathnayake; Redshaw, Matt; Ringle, Ryan; Valverde, Adrian; Yandow, Isaac; Low Energy Beam Ion Trap Team

    2017-09-01

    Over the last several decades, extremely sensitive, ultra-low background beta and gamma detection techniques have been developed. These techniques have enabled the observation of very rare processes, such as highly forbidden beta decays e.g. of 113Cd, 50V and 138La. Half-life measurements of highly forbidden beta decays provide a testing ground for theoretical nuclear models, and the comparison of calculated and measured energy spectra could enable a determination of the values of the weak coupling constants. Precision Q-value measurements also allow for systematic tests of the beta-particle detection techniques. We will present the results and current status of Q value determinations for highly forbidden beta decays. The Q values, the mass difference between parent and daughter nuclides, are measured using the high precision Penning trap mass spectrometer LEBIT at the National Superconducting Cyclotron Laboratory.

  2. HAGRID/ VANDLE spectroscopy of Rb decays

    Science.gov (United States)

    King, Thomas; Grzywacz, Robert; Taylor, Steven; Paulauskas, Stanley; Smith, Karl; Vandle Collaboration

    2017-09-01

    Many neutron-rich isotopes that contribute in both decay heat production and r-process nucleosynthesis have substantial beta-delayed neutron branching ratios. Beta-delayed neutron emission is a relatively complicated mechanism which can leave the daughter in an gamma-emitting excited state. A comprehensive understanding of their energy output and decay strength, S_beta, therefore requires the detection of both neutrons and gamma rays in coincidence. A series of measurements of delayed neutron precursors were performed at the On-Line Test Facility (OLTF) at the Oak Ridge National Laboratories using chemically selective ion sources and an enhanced VANDLE array. The main goal of this experiment was to revisit the decays of IAEA-marked priority precursors, including bromine, rubidium, cesium, and iodine, that are required to model the global properties in the fission of 238U.The unique data set, with neutron and gamma ray coincidences, benefited from the addition of a high-efficiency gamma-ray array, consisting of 16 LaBr3 crystals (HAGRiD), and a set of large volume NaI detectors to the VANDLE array. Characterization of and preliminary results from the new gamma-ray array for the decays of 94Rb and 97Rb will be presented. National Nuclear Security Administration under the Stewardship Science Academic Alliances program through DOE Award No. DE-NA0002132 and the Office of Nuclear Physics, U.S. Department of Energy under Award No. DE-FG02-96ER40983.

  3. Measurement of beta decay periods for Fe-Ni neutrons rich isotopes

    International Nuclear Information System (INIS)

    Czajkowski, S.

    1992-01-01

    Thermal fission of 239 Pu was used to produce 68,69 Co and 68 Fe isotopes, the lightest ones ever observed in thermal fission, at the ILL high-flux reactor, in Grenoble. Separated with the Lohengrin recoil spectrometer, then identified by means of a Δ E-E ionization chamber, fragments were implanted in a set of Si-detectors, where β-particles were detected too. The fission yields were determined, and the beta-decay half-lives were extracted from delayed coincidence analysis between ion implantation and the subsequent beta detection: They were found to be 0.27±0.05s, 0.18±0.10s, and 0.10±0.06s respectively for 69 Co, 68 Co, and 68 Fe. This method was adapted to a new experimental configuration: 65 Fe isotopes were produced from 86 Kr projectile fragmentation at 500 MeV/u on a Be target. Selected ions were separated with the fragment separator FRS at GSI (Darmstadt), tuned in the monoenergetic mode. Fragments were identified by ΔE-ToF, slowed down, and then implanted in two rows of PIN-diodes that provided an additional range selection. The half-life were determined from the analysis of the decay chain Fe-Co-Ni: it was found 0.4±0.2s. Production rates obtained with the two methods are compared at the end of this work

  4. Probing the N = Z Line via β Decay

    International Nuclear Information System (INIS)

    Markku Oinonen

    1999-01-01

    This contribution reports several beta-decay studies performed at ISOLDE On-Line Mass Separator at CERN recently for nuclei close to N = Z line. Beta decay of 58 Zn provides a possibility to compare Gamow-Teller strength extracted from complementary beta-decay studies and charge-exchange reactions. Measurement on beta-decay half-life of 70 Kr shows importance of experimental information in modeling the path of the astrophysical rp process. Decay of 71 Kr is an example of a mirror beta decay and extends the systematics of these particular decays towards highly deformed region close to A = 80

  5. Calculating beta decay in the deformed self-consistent quasiparticle random phase approximation

    Energy Technology Data Exchange (ETDEWEB)

    Engel, Jonathan, E-mail: engelj@physics.unc.edu [Department of Physics and Astronomy, University of North Carolina, Chapel Hill, NC 27599-3255 (United States); Mustonen, M. T., E-mail: mika.mustonen@yale.edu [Department of Physics and Astronomy, University of North Carolina, Chapel Hill, NC 27599-3255 (United States); Center for Theoretical Physics, Sloane Physics Laboratory, Yale University, New Haven, CT 06052 (United States)

    2016-06-21

    We discuss a recent global calculation of beta-decay rates in the self-consistent Skyrme quasiparticle random phase approximation (QRPA), with axially symmetric nuclear deformation treated explicitly. The calculation makes makes use of the finite-amplitude method, first proposed by Nakatsukasa and collaborators, to reduce computation time. The results are comparable in quality to those of several other global QRPA calculations. The QRPA may have reached the limit of its accuracy.

  6. Simulation of double beta decay in the 'SeXe' TPC

    Energy Technology Data Exchange (ETDEWEB)

    Mauger, F [LPC Caen and University of Caen, ENSICAEN, 6 Bd Marechal Juin, 14050 CAEN CEDEX 4 (France)

    2007-04-15

    In 2004, the NEMO collaboration has started some preliminary studies for a next-generation double beta decay experiment: SuperNEMO. The possibility to use a large gaseous TPC has been investigated using simulation and extrapolation of former experiments. In this talk, I report on the reasons why such techniques have not been selected in 2004 and led the NEMO collaboration to reuse the techniques implemented within the NEMO3 detector.

  7. The Milano-Gran Sasso double beta decay experiment: toward a 20-crystal array

    International Nuclear Information System (INIS)

    Alessandrello, A.; Brofferio, C.; Bucci, C.; Cremonesi, O.; Fiorini, E.; Giuliani, A.; Nucciotti, A.; Pavan, M.; Pessina, G.; Previtali, E.; Zanotti, L.

    1996-01-01

    TeO 2 thermal detectors are being used by the Milano group to search for neutrinoless double beta decay of 130 Te. An upper limit for neutrinoless decay half life of 2.1 x 10 22 yr at 90% CL obtained with a 334 g TeO 2 detector has been previously reported. To improve the sensitivity of the experiment an array of twenty 340 g TeO 2 crystals will be realised in the next future. As a first step toward the realisation of that experiment a 4 crystal detector has been tested in the Gran Sasso refrigerator. Detector performances, data acquisition and analysis are discussed. (orig.)

  8. Results on neutrinoless double beta decay of 76Ge from GERDA Phase I

    International Nuclear Information System (INIS)

    Palioselitis, Dimitrios

    2015-01-01

    The Germanium Detector Array (GERDA) experiment is searching for the neutrinoless double beta (0νββ) decay of 76 Ge by operating bare germanium diodes in liquid argon. GERDA is located at the Gran Sasso National Laboratory (LNGS) in Italy. During Phase I, a total exposure of 21.6 kg yrand a background index of 0.01 cts/(keVkg yr) were reached. No signal was observed and a lower limit of T 0ν 1/2 > 2.1 · 10 25 yr(90% C.L.) is derived for the half life of the 0νββ decay of 76 Ge. (paper)

  9. Beta-decay strength and isospin mixing studies in the sd and fp-shells

    International Nuclear Information System (INIS)

    Jokinen, A.; Aeystoe, J.; Dendooven, P.; Honkanen, A.; Lipas, P.; Peraejaervi, K.; Oinonen, M.; Siiskonen, T.

    1998-01-01

    We have studied beta decays of M T 41 Ti shows a large, 10(8) %, isospin mixing of IAS and the Gamow-Teller strength is observed to be quenched by a factor of q 2 =0.64. These results can be reproduced qualitatively in our shell model calculations. We have observed for the first time proton and gamma decay of the isobaric analogue state in 23 Mg. Our results on the isospin mixing of the isobaric analogue state agrees well with the shell model calculations. The obtained proton branch of the IAS is used to extract the transition strength for the reaction 22 Na(p,γ) 23 Mg

  10. The BetaCage: Ultrasensitive Screener for Radioactive Backgrounds

    Science.gov (United States)

    Thompson, Michael; BetaCage Collaboration

    2017-09-01

    Rare event searches, such as dark matter detection and neutrinoless double beta decay, require screening of materials for backgrounds such as beta emission and alpha decaying isotopes. The BetaCage is a proposed ultra-sensitive time-projection chamber to screen for alpha-emitting and low energy beta-emitting (10-200 keV) contaminants. The expected sensitivity is 0.1 beta particles (perkeV -m2 - day) and 0.1 alpha particles (perm2 - day) , where the former will be limited by Compton scattering of external photons in the screening samples and the latter is expected to be signal-limited. The prototype BetaCage under commissioning at South Dakota School of Mines & Technology is filled with P10 gas (10% methane, 90% argon) in place of neon and is 40×40×20 cm in size. Details on design, construction and characterization will be presented.

  11. BetaShape: A new code for improved analytical calculations of beta spectra

    Directory of Open Access Journals (Sweden)

    Mougeot Xavier

    2017-01-01

    Full Text Available The new code BetaShape has been developed in order to improve the nuclear data related to beta decays. An analytical model was considered, except for the relativistic electron wave functions, for ensuring fast calculations. Output quantities are mean energies, log ft values and beta and neutrino spectra for single and multiple transitions. The uncertainties from the input parameters, read from an ENSDF file, are propagated. A database of experimental shape factors is included. A comparison over the entire ENSDF database with the standard code currently used in nuclear data evaluations shows consistent results for the vast majority of the transitions and highlights the improvements that can be expected with the use of BetaShape.

  12. Beta decay to the second 2+ excited state of 122Te

    International Nuclear Information System (INIS)

    Hayashi, Takeo; Yamada, Shigeru

    1976-01-01

    The first-forbidden beta transition in Sb-122 was studied by the angular correlation experiment and the beta-spectra. The special precautions were paid for counting the beta particles having energy lower than 750 keV in the beta-gamma angular correlation measurement. The sources of Sb-122 were obtained by irradiating enriched Sb-121 in the Kyoto University reactor. The reduced beta coefficient R(E) was obtained from the angular correlation function. The beta spectrum measurement was performed with a sector type double focusing beta-ray spectrometer. The R(E) values for the beta transitions were analyzed by using the simplex method as used by Manthuruthil and Poirier to compare the angular correlation data with the exact formula given by Morita and Morita. Sets of the nuclear matrix parameters thus obtained show that the condition for the cancellation effect is satisfied in the beta transition. (Kato, T.)

  13. Decay energy of Fe from its inner Bremsstrahlung spectrum

    Indian Academy of Sciences (India)

    Fe decays by electron capture process with a half-life of 2.7 years. ... The 'source' was tested for the presence of ¬ impurities using a beta ray spectrometer and found to be ... age of 30 experiments is termed as mean source plus background.

  14. Study of {sup 193}Os beta{sup -} decay; Estudo do decaimento beta{sup -} do {sup 193}Os

    Energy Technology Data Exchange (ETDEWEB)

    Zahn, Guilherme Soares

    2006-07-01

    In this work, the excited levels of {sup 193}Ir populated by the beta{sup -} decay of {sup 193}Os (T{sub 1/2} {approx} 30h) were investigated. For that purpose, {approx} 5 mg samples of 99%-enriched {sup 192}Os were irradiated under a thermal neutron flux of {approx} 10{sup 12} s{sup -1} and then analysed both using single gamma spectroscopy and a 4-detector multi parametric acquisition facility, which provided data for both a gamma gamma coincidence analysis and a directional angular correlation gamma gamma ({theta} ) study. From these data, 28 transitions were added to this decay scheme, 11 of which were previously known from nuclear reactions and 17 observed for the first time. Eight excited levels were also added to the decay scheme, 3 of which were known from nuclear reaction studies - the remaining 5 are suggested for the first time. Moreover, it was possible to confirm suspicions found in reference that the levels at 848.93 keV and 849.093 keV are indeed the same; it was also possible to confirm the existence of an excited level at 806.9 keV, which had been inferred, but not experimentally confirmed in beta decay studies to date. The angular correlation analysis allowed for the definition of the spin of the excited level at 874 keV as 5/2{sup +;} moreover, the results showed a 79% probability that the spin of the 1078 keV level is 5/2/'-, and also restricted the spin possibilities for the new excited level at 960 keV to two values (1/2 or 3/2). It was also possible to measure the multipolarity mixing ratio ({delta}{sub Ln+1}/L{sub n}) for 43 transitions - 19 of them for the first time and most of the others with a better precision than previously known. Finally, an attempt was made to understand the low-lying levels structure for this nucleus using a theoretical model, which reproduced the ground state and the two lowest-lying excited levels in {sup 193}Ir. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

    Alduino, C.; Avignone, F.T.; Chott, N.; Creswick, R.J.; Rosenfeld, C.; Wilson, J. [University of South Carolina, Department of Physics and Astronomy, Columbia, SC (United States); Alfonso, K.; Hickerson, K.P.; Huang, H.Z.; Liu, X.; Trentalange, S.; Zhu, B.X. [University of California, Department of Physics and Astronomy, Los Angeles, CA (United States); Artusa, D.R. [University of South Carolina, Department of Physics and Astronomy, Columbia, SC (United States); INFN-Laboratori Nazionali del Gran Sasso, Assergi, L' Aquila (Italy); Azzolini, O.; Camacho, A.; Keppel, G.; Palmieri, V.; Pira, C. [INFN-Laboratori Nazionali di Legnaro, Legnaro, Padova (Italy); Banks, T.I.; Drobizhev, A.; Freedman, S.J.; Hennings-Yeomans, R.; O' Donnell, T.; Wagaarachchi, S.L. [University of California, Department of Physics, Berkeley, CA (United States); Lawrence Berkeley National Laboratory, Nuclear Science Division, Berkeley, CA (United States); Bari, G.; Deninno, M.M. [INFN-Sezione di Bologna, Bologna (Italy); Beeman, J.W. [Lawrence Berkeley National Laboratory, Materials Science Division, Berkeley, CA (United States); Bellini, F.; Cardani, L.; Casali, N.; Cosmelli, C.; Ferroni, F. [Sapienza Universita di Roma, Dipartimento di Fisica, Rome (Italy); INFN-Sezione di Roma, Rome (Italy); Bersani, A.; Caminata, A. [INFN-Sezione di Genova, Genova (Italy); Biassoni, M.; Carbone, L.; Cremonesi, O.; Ferri, E.; Giachero, A.; Pessina, G.; Previtali, E.; Rusconi, C. [INFN-Sezione di Milano Bicocca, Milan (Italy); Brofferio, C.; Capelli, S.; Carniti, P.; Cassina, L.; Chiesa, D.; Clemenza, M.; Faverzani, M.; Fiorini, E.; Gironi, L.; Gotti, C.; Maino, M.; Nucciotti, A.; Pavan, M.; Pozzi, S.; Sisti, M.; Terranova, F.; Zanotti, L. [Universita di Milano-Bicocca, Dipartimento di Fisica, Milan (Italy); INFN-Sezione di Milano Bicocca, Milan (Italy); Bucci, C.; Cappelli, L.; D' Addabbo, A.; Di Vacri, M.L.; Gorla, P.; Pattavina, L.; Pirro, S. [INFN-Laboratori Nazionali del Gran Sasso, Assergi, L' Aquila (Italy); Canonica, L. [INFN-Laboratori Nazionali del Gran Sasso, Assergi, L' Aquila (Italy); Massachusetts Institute of Technology, Cambridge, MA (United States); Cao, X.G.; Fang, D.Q.; Ma, Y.G.; Wang, H.W.; Zhang, G.Q. [Chinese Academy of Sciences, Shanghai Institute of Applied Physics, Shanghai (China); Copello, S.; Di Domizio, S.; Fernandes, G.; Marini, L.; Pallavicini, M. [INFN-Sezione di Genova, Genova (Italy); Universita di Genova, Dipartimento di Fisica, Genova (Italy); Cushman, J.S.; Davis, C.J.; Heeger, K.M.; Lim, K.E.; Maruyama, R.H. [Yale University, Department of Physics, New Haven, CT (United States); Dafinei, I.; Morganti, S.; Mosteiro, P.J.; Orio, F.; Pettinacci, V.; Tomei, C.; Vignati, M. [INFN-Sezione di Roma, Rome (Italy); Dell' Oro, S. [INFN-Laboratori Nazionali del Gran Sasso, Assergi, L' Aquila (Italy); INFN-Gran Sasso Science Institute, L' Aquila (Italy); Feintzeig, J.; Fujikawa, B.K.; Mei, Y.; Smith, A.R. [Lawrence Berkeley National Laboratory, Nuclear Science Division, Berkeley, CA (United States); Franceschi, M.A.; Ligi, C.; Napolitano, T.; Piperno, G. [INFN-Laboratori Nazionali di Frascati, Frascati, Rome (Italy); Giuliani, A.; Tenconi, M. [Universite Paris-Saclay, CSNSM, Univ. Paris-Sud, CNRS/IN2P3, Orsay (France); Gladstone, L.; Leder, A.; Winslow, L.A. [Massachusetts Institute of Technology, Cambridge, MA (United States); Gutierrez, T.D. [California Polytechnic State University, Physics Department, San Luis Obispo, CA (United States); Haller, E.E. [Lawrence Berkeley National Laboratory, Materials Science Division, Berkeley, CA (United States); University of California, Department of Materials Science and Engineering, Berkeley, CA (United States); Han, K. [Yale University, Department of Physics, New Haven, CT (United States); Shanghai Jiao Tong University, Department of Physics and Astronomy, Shanghai (China); Hansen, E. [University of California, Department of Physics and Astronomy, Los Angeles, CA (United States); Massachusetts Institute of Technology, Cambridge, MA (United States); Kadel, R. [Lawrence Berkeley National Laboratory, Physics Division, Berkeley, CA (United States); Kolomensky, Yu.G. [University of California, Department of Physics, Berkeley, CA (United States); Lawrence Berkeley National Laboratory, Nuclear Science Division, Berkeley, CA (United States); Lawrence Berkeley National Laboratory, Physics Division, Berkeley, CA (United States); Martinez, M. [Sapienza Universita di Roma, Dipartimento di Fisica, Rome (Italy); INFN-Sezione di Roma, Rome (Italy); Universidad de Zaragoza, Laboratorio de Fisica Nuclear y Astroparticulas, Zaragoza (Spain); Moggi, N. [INFN-Sezione di Bologna, Bologna (Italy); Alma Mater Studiorum-Universita di Bologna, Dipartimento di Scienze per la Qualita della Vita, Bologna (Italy); Nones, C. [Service de Physique des Particules, CEA/Saclay, Gif-sur-Yvette (France); Norman, E.B.; Wang, B.S. [Lawrence Livermore National Laboratory, Livermore, CA (United States); University of California, Department of Nuclear Engineering, Berkeley, CA (United States); Ouellet, J.L. [University of California, Department of Physics, Berkeley, CA (United States); Lawrence Berkeley National Laboratory, Nuclear Science Division, Berkeley, CA (United States); Massachusetts Institute of Technology, Cambridge, MA (United States); Pagliarone, C.E. [INFN-Laboratori Nazionali del Gran Sasso, Assergi, L' Aquila (Italy); Universita degli Studi di Cassino e del Lazio Meridionale, Dipartimento di Ingegneria Civile e Meccanica, Cassino (Italy); Sangiorgio, S.; Scielzo, N.D. [Lawrence Livermore National Laboratory, Livermore, CA (United States); Santone, D. [INFN-Laboratori Nazionali del Gran Sasso, Assergi, L' Aquila (Italy); Universita dell' Aquila, Dipartimento di Scienze Fisiche e Chimiche, L' Aquila (Italy); Singh, V. [University of California, Department of Physics, Berkeley, CA (US); Taffarello, L. [INFN-Sezione di Padova, Padova (IT); Wise, T. [Yale University, Department of Physics, New Haven, CT (US); University of Wisconsin, Department of Physics, Madison, WI (US); Woodcraft, A. [University of Edinburgh, SUPA, Institute for Astronomy, Edinburgh (GB); Zimmermann, S. [Lawrence Berkeley National Laboratory, Engineering Division, Berkeley, CA (US); Zucchelli, S. [INFN-Sezione di Bologna, Bologna (IT); Alma Mater Studiorum-Universita di Bologna, Dipartimento di Fisica e Astronomia, Bologna (IT)

    2017-01-15

    We report on the measurement of the two-neutrino double-beta decay half-life of {sup 130}Te with the CUORE-0 detector. From an exposure of 33.4 kg year of TeO{sub 2}, the half-life is determined to be T{sub 1/2}{sup 2ν} = [8.2 ± 0.2 (stat.) ± 0.6 (syst.)] x 10{sup 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 {sup 130}Te neutrinoless double-beta decay region of interest. (orig.)

  16. Magnetic moment and beta decay of RaE

    International Nuclear Information System (INIS)

    Morita, Masato; Ohtsubo, Hisao; Arita, Kozo.

    1976-01-01

    Asymmetry of the beta-ray angular distribution in polarized RaE is evaluated with the numerical values of nuclear matrix elements, i∫r, ∫α and ∫sigma x r, which are derived by the method of the least chi-square fit to the experimental data on the spectral shape, longitudinal polarization and ft value. The magnetic moment of RaE is known to have a negative sign from this calculation, the measured asymmetry in Tokyo and the knowledge about the internal magnetic field at decaying nucleus. A consistent explanation of i∫r, ∫sigma x r and the magnetic moment of RaE is obtained in a shell model, where the tensor forces in the residual interaction and the core polarization are properly taken into account. (auth.)

  17. Beta decay and other processes in strong electromagnetic fields

    International Nuclear Information System (INIS)

    Akhmedov, E. Kh.

    2011-01-01

    We consider effects of the fields of strong electromagnetic waves on various characteristics of quantum processes. After a qualitative discussion of the effects of external fields on the energy spectra and angular distributions of the final-state particles as well as on the total probabilities of the processes (such as decay rates and total cross sections), we present a simple method of calculating the total probabilities of processes with production of nonrelativistic charged particles. Using nuclear β decay as an example, we study the weak- and strong-field limits, as well as the field-induced β decay of nuclei stable in the absence of the external fields, both in the tunneling and multiphoton regimes. We also consider the possibility of accelerating forbidden nuclear β decays by lifting the forbiddeness due to the interaction of the parent or daughter nuclei with the field of a strong electromagnetic wave. It is shown that for currently attainable electromagnetic fields all effects on total β-decay rates are unobservably small.

  18. 20F beta spectrum shape and weak interaction tests

    Science.gov (United States)

    Voytas, Paul; George, Elizabeth; Chuna, Thomas; Naviliat-Cuncic, Oscar; Hughes, Max; Huyan, Xueying; Minamisono, Kei; Paulauskas, Stanley

    2016-09-01

    Precision measurements of the shape of beta spectra can test our understanding of the weak interaction. We are carrying out a measurement of the shape of the energy spectrum of β particles from 20F decay. The primary motivation is to test the so-called strong form of the conserved vector current (CVC) hypothesis. The measurement should also enable us to place competitive limits on the contributions of exotic tensor couplings in beta decay. We aim to achieve a relative precision better than 3% on the linear contribution to the shape. This represents an order of magnitude improvement compared to previous experiments in 20F. In order to control systematic effects, we are using a technique that takes advantage of high energy radioactive beams at the NSCL to implant the decaying nuclei in scintillation detectors deeply enough that the emitted beta particles cannot escape. The β-particle energy is measured with the implantation detector after switching off the implantation beam. Ancillary detectors are used to identify the 1.633-MeV γ-rays following the 20F β decay for coincidence measurements in order to tag the transition of interest and to reduce backgrounds. We report on the status of the analysis. Supported in part with Awards from the NSCL PAC and the National Science Foundation under Grant No. PHY-1506084.

  19. Pulse-shape discrimination techniques for the COBRA double beta-decay experiment at LNGS

    Science.gov (United States)

    Zatschler, S.; COBRA Collaboration

    2017-09-01

    In modern elementary particle physics several questions arise from the fact that neutrino oscillation experiments have found neutrinos to be massive. Among them is the so far unknown nature of neutrinos: either they act as so-called Majorana particles, where one cannot distinguish between particle and antiparticle, or they are Dirac particles like all the other fermions in the Standard Model. The study of neutrinoless double beta-decay (0νββ-decay), where the lepton number conservation is violated by two units, could answer the question regarding the underlying nature of neutrinos and might also shed light on the mechanism responsible for the mass generation. So far there is no experimental evidence for the existence of 0νββ-decay, hence, existing experiments have to be improved and novel techniques should be explored. One of the next-generation experiments dedicated to the search for this ultra-rare decay is the COBRA experiment. This article gives an overview of techniques to identify and reject background based on pulse-shape discrimination.

  20. Probing new physics in the neutrinoless double beta decay using electron angular correlation

    Energy Technology Data Exchange (ETDEWEB)

    Ali, A. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Borisov, A.V.; Zhuridov, D.V. [Moscow State Univ. (Russian Federation). Faculty of Physics

    2007-06-15

    The angular correlation of the electrons emitted in the neutrinoless double beta decay (0{nu}2{beta}) is presented using a general Lorentz invariant effective Lagrangian for the leptonic and hadronic charged weak currents. We show that the coefficient K in the angular correlation d{gamma}/dcos {theta} {proportional_to}(1-K cos {theta}) is essentially independent of the nuclear matrix element models and present its numerical values for the five nuclei of interest ({sup 76}Ge, {sup 82}Se, {sup 100}Mo, {sup 130}Te, and {sup 136}Xe), assuming that the 0{nu}2{beta}-decays in these nuclei are induced solely by a light Majorana neutrino, {nu}{sub M}. This coefficient varies between K=0.82 (for the {sup 76}Ge nucleus) and K=0.88 (for the {sup 82}Se and {sup 100}Mo nuclei), calculated taking into account the effects from the nucleon recoil, the S and P-waves for the outgoing electrons and the electron mass. Deviation of K from its values derived here would indicate the presence of New Physics (NP) in addition to a light Majorana neutrino, and we work out the angular coefficients in several {nu}{sub M}+NP scenarios for the {sup 76}Ge nucleus. As an illustration of the correlations among the 0{nu}2{beta} observables (half-life T{sub 1/2}, the coefficient K, and the effective Majorana neutrino mass vertical stroke left angle m right angle vertical stroke) and the parameters of the underlying NP model, we analyze the left-right symmetric models, taking into account current phenomenological bounds on the right-handed W{sub R}-boson mass and the left-right mixing parameter {zeta}. (orig.)

  1. First direct observation of bound-state beta-decay: Measurements of branching and lifetime of 207Tl81+ fragments

    International Nuclear Information System (INIS)

    Boutin, D.

    2005-08-01

    The first experimental observation of bound-state beta-decay showed, that due solely to the electron stripping, a stable nuclide, e.g. 163 Dy, became unstable. Also a drastic modification of the half-life of bare 187 Re, from 4.12(2) x 10 10 years down to 32.9(20) years, could be observed. It was mainly due to the possibility for the mother nuclide to decay into a previously inaccessible nuclear level of the daughter nuclide. It was proposed to study a nuclide where this decay mode was competing with continuum-state beta-decay, in order to measure their respective branchings. The ratio β b /β c could also be evaluated for the first time. 207 Tl was chosen due to its high atomic number, and Q-value of about 1.4 MeV, small enough to enhance the β b probability and large enough to allow the use of time-resolved Schottky Mass Spectrometry (SMS) to study the evolution of mother and bound-state beta-decay daughter ions. The decay properties of the ground state and isomeric state of 207 Tl 81+ have been investigated at the GSI accelerator facility in two separate experiments. For the first time β-decay where the electron could go either to a bound state (atomic orbitals) and lead to 207 Pb 81+ as a daughter nuclide, or to a continuum state and lead to 207 Pb 82+ , has been observed. The respective branchings of these two processes could be measured as well. The deduced total nuclear half-life of 255(17) s for 207 Tl 81+ , was slightly modified with respect to the half-life of the neutral atom of 286(2) s. It was nevertheless in very good agreement with calculations based on the assumption that the beta-decay was following an allowed type of transition. The branching β b /β c =0.192(20), was also in very good agreement with the same calculations. The application of stochastic precooling allowed to observe in addition the 1348 keV short-lived isomeric state of 207 Tl. The half-life of this isomeric state was measured as 1.47(32) s, which shows a small deviation

  2. Status of the Frejus experiment on the neutrinoless double beta decay of the 76Ge

    International Nuclear Information System (INIS)

    Morales, A.; Nunez-Lagos, R.; Morales, J.; Puimedon, J.; Villar, J.A.; Dassie, D.; Hubbert, Ph.; Leccia, F.; Mennrath, P.; Villard, M.

    1987-01-01

    A brief account of the design, experimental set up and status of the Frejus experiments on the neutrinoless double beta decay of 76 Ge is presented. The theoretical implications and expectatives of this experimental research are analized. A comparison with other dedicated experiments is also reported. (author)

  3. Future perspectives of double beta decay and dark matter search - GENIUS

    International Nuclear Information System (INIS)

    Klapdor-Kleingrothaus, H.V.; Hellmig, J.; Hirsch, M.

    1998-01-01

    The recent results from the HEIDELBERG-MOSCOW experiment have demonstrated the large potential of double beta decay to search for new physics beyond the standard model. To increase by a major step the present sensitivity for double beta decay and dark matter search, much bigger source strengths and much lower backgrounds are needed than used in experiments under operation at present or under construction. We describe here a project which would operate one tonne of 'naked' enriched germanium-detectors in liquid nitrogen as shielding in an underground set-up (GENIUS). It improves the sensitivity of neutrino masses to 0.01 eV. A 10 tonne version would probe neutrino masses even down to 10 -3 eV. The first version would allow us to test the atmospheric neutrino problem, the second at least part of the solar neutrino problem. Both versions would allow, in addition, significant contributions to testing several classes of GUT models. These are especially tests of R-parity breaking and conserving supersymmetry models - including sneutrino masses - leptoquark masses and mechanism and right-handed W-boson masses comparable with LHC. The second issue of the experiment is the search for dark matter in the universe. The full MSSM parameter space for the prediction of neutralinos as dark matter particles could be covered already in a first step of the full experiment using only 100 kg of 76 Ge or even of natural Ge making the experiment competitive with LHC in the search for supersymmetry. (author)

  4. Total Absorption Spectroscopy Study of the Beta Decay of 60Mn to Constrain the Neutron Capture Rate of 60Fe

    Science.gov (United States)

    Richman, Debra; Spyrou, Artemis; Dombos, Alex; Couture, Aaron; e15034 Collaboration

    2017-09-01

    Interest in 60Fe, a long lived radioisotope synthesized in massive stars, has recently peaked. The signature of its decay allows us to probe astrophysical processes, events such as the early formation of the solar system and nucleosynthesis. To understand these observations a complete understanding of the creation, destruction and nuclear properties of 60Fe in the astrophysical environment are required. Using the beta decay of 60Mn in conjunction with total absorption spectroscopy (TAS), made possible by the high efficiency gamma ray calorimeter SuN (Summing NaI detector) at the National Superconducting Cyclotron Laboratory (NSCL), to study the distribution of beta-decay intensity over the daughter-nucleus 60Fe, provides information about the structure of the daughter and improves the predictive power of astrophysical models. In addition to the ongoing TAS analysis, The Beta-Oslo method will be used to extract the nuclear level density and gamma-strength function of 60Fe providing much needed constraints on the neutron capture reaction rate responsible for the creation of this nucleus.

  5. Study of the background of the neutrinoless double {beta} decay with the detector NEMO 2: contribution arising from the radon diffusion and internal pollution of the source {sup 214}Bi have been estimated; Etude du bruit de fond de la double-desintegration {beta} sans emission de neutrino dans le detecteur NEMO 2: contribution du radon ambiant et mesure de la pollution interne de la source en {sup 214}Bi

    Energy Technology Data Exchange (ETDEWEB)

    Mauger, F.

    1995-02-01

    The NEMO experiment is designed to understand the nature of the neutrino by studying the double beta decay of Mo-100 which is related to the Majorana neutrino effective mass. In this kind of experiment a good understanding of the different sources of background is crucial as only few events are expected per year at the required level of sensitivity. In this thesis we present the main theoretical and experimental aspects of the measurement of the neutrinoless double beta decay of Mo-100 with the prototype detector NEMO2. The goal of this study is to obtain a realistic interpretation of the few events detected at high energy in the two-electron channel as a background to neutrinoless double beta decay. In particular, the contribution arising from Bi-214 has been investigated. These events have been selected and analysed by means of the beta-alpha decays of Bi-214 into Pb-210. The events are characterized by a delayed track in the wire chamber and the corresponding signal is rather clean. The study has demonstrated the diffusion of Rn-222 into the detector and its contribution to Bi-214 pollution has been estimated. A measurement of the Bi-214 internal contamination of the source has been made as well as an estimation of the Bi-214 deposit due to Rn-222. As a result of this study it appears that, under the conditions of the NEMO2 experiment, the Bi and Rn contributions are of the same order of magnitude as the background induced at high energy by two-neutrino double beta decay. In conclusion, the backgrounds of the neutrinoless double beta decay of Mo-100 are well understood in the NEMO2 experiment leading to an extrapolation for the NEMO3 experiment. (authors).

  6. Beta-decay asymmetries in polarized /sup 12/B and /sup 12/N, and the G-parity nonconservation

    Energy Technology Data Exchange (ETDEWEB)

    Sugimoto, K; Tanihata, I [Osaka Univ., Toyonaka (Japan). Lab. of Nuclear Studies

    1976-10-01

    The decay asymmetries (A) in polarized /sup 12/B and /sup 12/N have been measured as a function of ..beta..-ray energy, E. The coefficients asub(+-), in A=+-P(p/E)(1+asub(+-)E), have been determined to be a-(/sup 12/B)=+(0.31+-0.06)%/MeV and a+(/sup 12/N)=-(0.21+-0.07)%/MeV. The experimental value, asub(-)-asub(+)=(0.52+-0.09)%/MeV, is larger than the prediction according to conservation of vector current, (asub(-)-asub(+))cvc asymptotically equals 0.27%/MeV, which includes no second-class current. Thus, the result is in favor of the existence of the second-class induced-tensor current.

  7. Double Beta Decay with Ge-detectors - and the future of Double Beta and Dark Matter Search (GENIUS)

    International Nuclear Information System (INIS)

    Klapdor-Kleingrothaus, H.V.

    1999-01-01

    Nuclear double beta decay provides an extraordinarily broad potential to search for beyond Standard Model physics, probing already now the TeV scale, on which new physics should manifest itself. These possibilities are reviewed here. First, the results of present generation experiments are presented. The most sensitive one of them - the Heidelberg-Moscow experiment in the Gran Sasso, using enriched 76 Ge - probes the electron neutrino mass now in the sub eV region and will reach a limit of ∼ 0.1 eV in a few years. Basing to a large extent on the theoretical work of the Heidelberg Double Beta Group in the last two years, results are obtained also for SUSY models (R-parity breaking, sneutrino mass), leptoquarks (leptoquark-Higgs coupling), compositeness, right-handed W boson mass and others. These results are comfortably competitive to corresponding results from high-energy accelerators like TEVATRON, HERA, etc. Second, future perspectives of ββ research are discussed. A new Heidelberg experimental proposal (GENIUS) is presented which would allow to increase the sensitivity for Majorana neutrino masses from the present level of at best 0.1 eV down to 0.01 or even 0.001 eV. Its physical potential would be a breakthrough into the multi-TeV range for many beyond standard models. Its sensitivity for neutrino oscillation parameters would be larger than of all present terrestrial neutrino oscillation experiments and of those planned for the future. It would further, already in a first step, cover almost the full MSSM parameter space for prediction of neutralinos as cold dark matter, making the experiment competitive to LHC in the search for supersymmetry

  8. Spectroscopy of light neutron deficient nuclei: 31Ar and 27S decays

    International Nuclear Information System (INIS)

    Borrel, V.

    1991-01-01

    Light neutron-deficient nuclei exhibit several interesting decay modes. In some cases, beta-delayed alpha emission becomes possible, and beta-delayed three-proton emission can be allowed. The energy spectra of the emitted protons should give informations on the position of the isobaric analog state and on its deexcitation modes. Experimental results obtained at GANIL with the LISE spectrometer on the decay of the isotopes 31 Ar and 27 S are presented. These data are discussed and compared with the predicted isobaric analog state excitation energies and with shell-model calculations. (G.P.) 13 refs.; 7 figs.; 1 tab

  9. Precision measurement of the half-life and branching ratio of the T=1/2 mirror $\\beta$-decay of $^{37}$K

    CERN Multimedia

    We propose to study the T=1/2 mirror $\\beta$-decay of $^{37}$K. Nuclear mirror $\\beta$-decay is a competitive means to test the electroweak model by means of the high-precision measurement of V$_{ud}$ element of the CKM quark mixing matrix. One key ingredient to obtain V$_{ud}$ is the force of the transition, Ft, which has to be determined with a relative precision below 10$^{−3}$. This quantity is related to the half-life T$_{1/2}$ of the decaying nucleus, the branching ratio BR for this decay and the mass difference between the mother and daughter nucleus (Q value). Another important feature is the mixing ratio $\\rho$ between the Fermi and the Gamow-Teller character of the transition. In most cases, $\\rho$ is the major contributor to the uncertainty on Ft. Available data concerning T$_{1/2}$ and BR of $^{37}$K suffer from a lack of precision that will be easily reduced by a dedicated experiment.

  10. Ultrafast Nonradiative Decay and Excitation Energy Transfer by Carotenoids in Photosynthetic Light-Harvesting Proteins

    Science.gov (United States)

    Ghosh, Soumen

    This dissertation investigates the photophysical and structural dynamics that allow carotenoids to serve as efficient excitation energy transfer donor to chlorophyll acceptors in photosynthetic light harvesting proteins. Femtosecond transient grating spectroscopy with optical heterodyne detection has been employed to follow the nonradiative decay pathways of carotenoids and excitation energy transfer to chlorophylls. It was found that the optically prepared S2 (11Bu+) state of beta-carotene decays in 12 fs fs to populate an intermediate electronic state, Sx, which then decays nonradiatively to the S 1 state. The ultrafast rise of the dispersion component of the heterodyne transient grating signal reports the formation of Sx intermediate since the rise of the dispersion signal is controlled by the loss of stimulated emission from the S2 state. These findings were extended to studies of peridinin, a carbonyl substituted carotenoid that serves as a photosynthetic light-harvesting chromophore in dinoflagellates. Numerical simulations using nonlinear response formalism and the multimode Brownian oscillator model assigned the Sx intermediate to a torsionally distorted structure evolving on the S2 potential surface. The decay of the Sx state is promoted by large amplitude out-of-plane torsional motions and is significantly retarded by solvent friction owing to the development of an intramolecular charge transfer character in peridinin. The slowing of the nonradiative decay allows the Sx state to transfer significant portion of the excitation energy to chlorophyll a acceptors in the peridinin-chlorophyll a protein. The results of heterodyne transient grating study on peridinin-chlorophyll a protein suggests two distinct energy transfer channels from peridinin to chlorophyll a: a 30 fs process involving quantum coherence and delocalized peridinin-Chl states and an incoherent, 2.5 ps process involving the distorted S2 state of peridinin. The torsional evolution on the S2

  11. Search for neutrinoless double beta decay with GERDA phase II

    Science.gov (United States)

    Agostini, M.; Bakalyarov, A. M.; Balata, M.; Barabanov, I.; Baudis, L.; Bauer, C.; Bellotti, E.; Belogurov, S.; 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.; Domula, A.; Doroshkevich, E.; Egorov, V.; Falkenstein, R.; 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.; Csáthy, J. Janicskó; Jochum, J.; Junker, M.; Kazalov, V.; Kihm, T.; Kirpichnikov, I. V.; Kirsch, A.; Kish, A.; Klimenko, A.; Kneißl, R.; Knies, J.; Knöpfle, K. T.; Kochetov, O.; Kornoukhov, V. N.; Kuzminov, V. V.; Laubenstein, M.; Lazzaro, A.; Lebedev, V. I.; Liao, H. Y.; Lindner, M.; Lippi, I.; Lubashevskiy, A.; Lubsandorzhiev, B.; Lutter, G.; Majorovits, B.; Maneschg, W.; Marissens, G.; Miloradovic, M.; Mingazheva, R.; Misiaszek, M.; Moseev, P.; Nemchenok, I.; Panas, K.; Pandola, L.; Pelczar, K.; Pullia, A.; Ransom, C.; Reissfelder, M.; Riboldi, S.; Rumyantseva, N.; Sada, C.; Salamida, F.; Schmitt, C.; Schneider, B.; Schönert, S.; Schreiner, J.; Schulz, O.; Schütz, A.-K.; Schwingenheuer, B.; Seitz, H.; Selivanenko, O.; Shevchik, E.; Shirchenko, M.; Simgen, H.; Smolnikov, A.; Stanco, L.; Vanhoefer, L.; Vasenko, A. A.; Veresnikova, A.; von Sturm, K.; Wagner, V.; Wegmann, A.; Wester, T.; Wiesinger, C.; Wojcik, M.; Yanovich, E.; Zhitnikov, I.; Zhukov, S. V.; Zinatulina, D.; Zuber, K.; Zuzel, G.

    2017-10-01

    The GERmanium Detector Array (gerda) experiment, located at the Gran Sasso underground laboratory in Italy, is one of the leading experiments for the search of 0νββ decay. In Phase II of the experiment 35.6 kg of enriched germanium detectors are operated. The application of active background rejection methods, such as a liquid argon scintillation light read-out and pulse shape discrimination of germanium detector signals, allowed to reduce the background index to the intended level of 10-3 cts/(keV.kg.yr). In the first five month of data taking 10.8 kg yr of exposure were accumulated. No signal has been found and together with data from Phase I a new limit for the neutrinoless double beta decay half-life of 76Ge of 5.3 . 1025 yr at 90% C.L. was established in June 2016. Phase II data taking is ongoing and will allow the exploration of half-lifes in the 1026 yr regime. The current status of data taking and an update on the background index are presented.

  12. Status of decay data of fission products

    International Nuclear Information System (INIS)

    Blachot, J.

    1978-01-01

    Fission products (F.P.) are neutron rich isotopes ranging from Zn to Tm. The status of decay data of F.P. was described at the Bologna Panel 1973 by Rudstam. Since then, FPND have improved in general, but still much is valid of what Rudstam said about the accuracies of FPND. The lack of decay data for the short lived F.P. has been considerably reduced, and some of the short lived F.P. have now well studied decay data. The present status of decay data is given in this review, which is composed of six sections. In the first one, the principal new facilities used in decay data measurements are reviewed. The second part is devoted to the total decay energy (Q). In the third Section, the half lives are treated. In the fourth and fifth Sections, beta and gamma energies and intensities, and also average values are discussed. Finally, the last Section considers the different files and compilations devoted to the decay of F.P

  13. Progress report on the Los Alamos tritium beta decay experiment

    International Nuclear Information System (INIS)

    Wilkerson, J.F.; Bowles, T.J.; Knapp, D.A.; Robertson, R.G.H.; Wark, D.L.

    1988-01-01

    Measurements near the endpoint of the tritium beta-decay spectrum using a gaseous molecular tritium source yield an essentially model-independent upper limit of 27 eV on the /ovr ν//sub e/ mass at the 95% confidence level. Since demonstrating from this initial measurement the successful operation of a gaseous source based system, most of our effort has been concentrated towards the upgrade and optimization of the experimental apparatus. The emphasis of this work has been to eliminate or further reduce effects that generate systematic errors. Based on realistic projections from our initial measurement, an ultimate sensitivity to neutrino mass of 10 eV is expected. 12 refs., 1 fig

  14. A scintillating bolometer array for double beta decay studies: The LUCIFER experiment

    Energy Technology Data Exchange (ETDEWEB)

    Gironi, L., E-mail: luca.gironi@mib.infn.it [Università degli Studi di Milano-Bicocca, Milano (Italy); INFN – Sezione di Milano-Bicocca, Milano (Italy)

    2016-07-11

    The main goal of the LUCIFER experiment is to study the neutrinoless double beta decay, a rare process allowed if neutrinos are Majorana particles. Although aiming at a discovery, in the case of insufficient sensitivity the LUCIFER technique will be the demonstrator for a higher mass experiment able to probe the entire inverted hierarchy region of the neutrino mass. In order to achieve this challenging result, high resolution detectors with active background discrimination capability are required. This very interesting possibility can be largely fulfilled by scintillating bolometers thanks to the simultaneous read-out of heat and light emitted by the interactions in the detector or by pulse shape analysis. - Highlights: • The LUCIFER technique will be the demonstrator for a higher mass experiment. • Scintillating bolometers allow high energy resolution and background discrimination. • The first choice for the LUCIFER tower are ZnSe crystals. • The LUCIFER setup will consist of an array of 30 individual single module detectors. • An array of ZnMoO4 crystals allowed the bolometric observation of the 2vDBD of {sup 100}Mo.

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

    Energy Technology Data Exchange (ETDEWEB)

    Cebrián, S.; Dafni, T.; González-Díaz, D.; Herrera, D. C.; Irastorza, I. G.; Luzón, G.; Ortiz de Solórzano, A.; Villar, J. A. [Laboratorio de Física Nuclear y Astropartículas, Universidad de Zaragoza, C/ Pedro Cerbuna 12, 50009 Zaragoza (Spain); Laboratorio Subterráneo de Canfranc, Paseo de los Ayerbe s/n, 22880 Canfranc Estación, Huesca (Spain); Pérez, J. [Instituto de Física Teórica, UAM/CSIC, Campus de Cantoblanco, 28049 Madrid (Spain); Bandac, I. [Laboratorio Subterráneo de Canfranc, Paseo de los Ayerbe s/n, 22880 Canfranc Estación, Huesca (Spain); Labarga, L. [Dpto. de Física Teórica, Universidad Autónoma de Madrid, Campus de Cantoblanco, 28049 Madrid (Spain); 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/ Catedrático José Beltrán, 2, 46980 Paterna, Valencia (Spain); 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.

  16. Minimally allowed neutrinoless double beta decay rates within an anarchical framework

    International Nuclear Information System (INIS)

    Jenkins, James

    2009-01-01

    Neutrinoless double beta decay (ββ0ν) is the only realistic probe of the Majorana nature of the neutrino. In the standard picture, its rate is proportional to m ee , the e-e element of the Majorana neutrino mass matrix in the flavor basis. I explore minimally allowed m ee values within the framework of mass matrix anarchy where neutrino parameters are defined statistically at low energies. Distributions of mixing angles are well defined by the Haar integration measure, but masses are dependent on arbitrary weighting functions and boundary conditions. I survey the integration measure parameter space and find that for sufficiently convergent weightings, m ee is constrained between (0.01-0.4) eV at 90% confidence. Constraints from neutrino mixing data lower these bounds. Singular integration measures allow for arbitrarily small m ee values with the remaining elements ill-defined, but this condition constrains the flavor structure of the model's ultraviolet completion. ββ0ν bounds below m ee ∼5x10 -3 eV should indicate symmetry in the lepton sector, new light degrees of freedom, or the Dirac nature of the neutrino.

  17. Decay of sup 7 sup 6 As

    CERN Document Server

    Camargo, S P D; Medeiros, J A G; Kenchian, G; Cruz, M T F

    1998-01-01

    The level structure of sup 7 sup 6 Se has been investigated by studying the gamma-rays emitted following the beta sup - decay of sup 7 sup 6 As. The energies and relative intensities of 45 gamma-rays have been determined with a better overall precision than previously. Two new transitions with 528.2 and 1232.4 keV have been found and placed in the level scheme. A new level, at 1791.5 keV excitation energy, is proposed. Seven transitions and three levels previously attributed to this decay scheme were not confirmed.

  18. Deformation of the N=Z nucleus $^{76}$Sr using $\\beta$-decay studies

    CERN Document Server

    Nacher, E; Rubio, B; Taín, J L; Cano-Ott, D; Courtin, S; Dessagne, P; Maréchal, F; Miehé, C; Poirier, E; García-Borge, M J; Escrig, D; Jungclaus, A; Sarriguren, P; Tengblad, O; Gelletly, W; Fraile-Prieto, L M; Le Scornet, G; Dessagne, Ph.; Miehe, Ch.

    2004-01-01

    A novel method of deducing the deformation of the N=Z nucleus $^{76}$Sr is presented. It is based on the comparison of the experimental Gamow-Teller strength distribution B(GT) from its $\\beta$-decay with the results of QRPA calculations. This method confirms previous indications of the strong prolate deformation of this nucleus in a totally independent and novel way. The measurement has been carried out with a large Total Absorption Gamma Spectrometer, "Lucrecia", newly installed at CERN-ISOLDE.

  19. MAJORANA Neutrinoless Double-Beta Decay DUSEL R and D. Final report

    International Nuclear Information System (INIS)

    Wilkerson, John F.

    2009-01-01

    The Majorana research and development is addressing key issues and risks related to the collaboration's goal of undertaking a search for neutrinoless double-beta decay (0νββ) in 76 Ge using an array of hyper-pure Ge-diodes (HPGe). The observation of this decay would provide critical insight into our understanding of neutrinos, yielding definitive evidence that neutrinos are Majorana particles and providing information on the absolute mass of neutrinos. Achieving sensitivities to 0νββ decay half-lives on the order of 10 26 years requires ultra-low backgrounds in the 2039 keV region where a 0νββ decay peak would be observed. The goal of our R and D program has been to demonstrate the feasibility of all components of Majorana and to provide an integrated evaluation framework, allowing for optimization of these components in terms of background, background suppression, and signal detection efficiency and acceptance. This report covers work carried out by Majorana collaboration members at the University of Washington as part of the overall Majorana collaboration activities. Specifically the Majorana group at the University of Washington was involved in moving forward on demonstrating technology for clean large-scale cryostats and mounting the HPGe crystals in low-mass holders. The UW activities included assistance in the procurement and assembly of an electroforming system for large size cryostats, and design and fabrication of prototype crystal mounting hardware.

  20. Neutrino mass bounds from neutrinoless double beta-decays and ...

    Indian Academy of Sciences (India)

    2016-01-21

    Jan 21, 2016 ... CMD model. In addition, we explore the interacting neutrino dark-energy model, where the ... This decay has a small energy release (E0 ≃ 18.6 keV) and a convenient lifetime (T1/2 = 12.3 yr). As the ...... Research Programme funded by the Korean Ministry of Science, ICT and Future Planning. (Grant No.

  1. Mirror decay of $^{75}$Sr

    CERN Document Server

    Huikari, J; Algora, A; Cederkäll, J; Courtin, S; Dessagne, P; Fraile-Prieto, L M; Franchoo, S; Fynbo, H O U; Huang Wan Xia; Jokinen, A; Knipper, A; Maréchal, F; Miehé, C; Nácher, E; Peräjärvi, K; Poirier, E; Weissman, L; Äystö, J

    2003-01-01

    The beta -decay of /sup 75/Sr to its mirror nucleus /sup 75/Rb was studied at the ISOLDE PSB facility at CERN by means of beta -delayed gamma and proton spectroscopy. The decay Q-value and beta -delayed gamma intensity were measured for the first time. These results, 10.60+or-0.22 MeV and 4.5/sub -0.7//sup +1.9/%, together with accurate measurements of the beta -decay half-life and beta -delayed proton branching ratio yielded the Gamow-Teller strength 0.35+or-0.05 for the mirror transition. Implications of the results on studies of deformation effects and on the path of the rapid proton capture process are discussed. (24 refs).

  2. Excitation functions of proton-induced reactions on natural Nd and production of radionuclides relevant for double beta decay: Completing measurement in 5-35 MeV energy range

    Czech Academy of Sciences Publication Activity Database

    Lebeda, Ondřej; Lozza, V.; Petzoldt, J.; Štursa, Jan; Zdychová, Vlasta; Zuber, K.

    2014-01-01

    Roč. 929, SEP (2014), s. 129-142 ISSN 0375-9474 R&D Projects: GA MŠk(XE) LM2011019 Institutional support: RVO:61389005 Keywords : proton activation * double beta decay * cross-section * production rates * natural neodymium Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 2.202, year: 2014

  3. Spectral and Temporal Properties of the Alpha and Beta Subunits and (alpha Beta) Monomer Isolated from Nostoc SP. Using Picosecond Laser Spectroscopy.

    Science.gov (United States)

    Dagen, Aaron J.

    1985-12-01

    The fluorescence decay profiles, relative quantum yield and transmission of the (alpha), (beta) and ((alpha)(beta)) complexes from phycoerythrin isolated from the photosynthetic antenna system of Nostoc sp. and measured by single picosecond laser spectroscopic techniques is studied. The fluorescence decay profiles of all three complexes are found to be intensity independent for the intensity range investigated ((TURN)4 x 10('13) to (TURN)4 x 10('15) photons-cm('-2) per pulse). The apparent decrease in the relative quantum yield of all three complexes as intensity increases is offset by a corresponding increase in the relative transmission. This evidence, along with the intensity independent fluorescence kinetics, suggests that exciton annihilation is absent in these complexes. The decay profiles are fit to models assuming energy transfer amongst fluorescing chromophores. The intraprotein transfer rate is found to be 100 ps in the (alpha) subunit, 666 ps in the (beta) subunit. Constraining these rates to be identical in the monomer results in explaining the monomer kinetics by an increase in the nonradiative rate of the f(,(beta)) chromophore, an apparent result of aggregation effects.

  4. Searching Neutrinoless Double Beta Decay with GERDA Phase II

    Science.gov (United States)

    Agostini, M.; Bakalyarov, A. M.; Balata, M.; Barabanov, I.; Baudis, L.; Bauer, C.; Bellotti, E.; Belogurov, S.; Bettini, A.; Bezrukov, L.; Bode, T.; Brudanin, V.; Brugnera, R.; Caldwell, A.; Cattadori, C.; Chernogorov, A.; Comellato, T.; D’Andrea, V.; Demidova, E. V.; di Marco, N.; Domula, A.; Doroshkevich, E.; Egorov, V.; Falkenstein, R.; Gangapshev, A.; Garfagnini, A.; Giordano, M.; Gooch, C.; Grabmayr, P.; Gurentsov, V.; Gusev, K.; Hahne, C.; Hakenmüller, J.; Hegai, A.; Heisel, M.; Hemmer, S.; Hiller, R.; Hofmann, W.; Holl, P.; Hult, M.; Inzhechik, L. V.; Ioannucci, L.; Csáthy, J. Janicskó; Jochum, J.; Junker, M.; Kazalov, V.; Kermaidic, Y.; 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.; Lindner, M.; Lippi, I.; Lubashevskiy, A.; Lubsandorzhiev, B.; Lutter, G.; Macolino, C.; Majorovits, B.; Maneschg, W.; Marissens, G.; Miloradovic, M.; Mingazheva, R.; Misiaszek, M.; Moseev, P.; Nemchenok, I.; Nisi, S.; Panas, K.; Pandola, L.; Pelczar, K.; Pullia, A.; Ransom, C.; Reissfelder, M.; Riboldi, S.; Rumyantseva, N.; Sada, C.; Sala, E.; Salamida, F.; Schmitt, C.; Schneider, B.; Schreiner, J.; Schulz, O.; Schweisshelm, B.; Schwingenheuer, B.; Schönert, S.; Schütz, A.-K.; Seitz, H.; Selivanenko, O.; Shevchik, E.; Shirchenko, M.; Simgen, H.; Smolnikov, A.; Stanco, L.; Vanhoefer, L.; Vasenko, A. A.; Veresnikova, A.; von Sturm, K.; Wagner, V.; Wegmann, A.; Wester, T.; Wiesinger, C.; Wojcik, M.; Yanovich, E.; Zhitnikov, I.; Zhukov, S. V.; Zinatulina, D.; Zschocke, A.; Zsigmond, A. J.; Zuber, K.; Zuzel, G.

    An observation of neutrinoless double beta (0νββ) decay would allow to shed light onto the nature of neutrinos. GERDA (GERmanium Detector Array) aims to discover this process in a background-free search using 76Ge. The experiment is located at the Laboratori Nazionali del Gran Sasso (LNGS) of the Istituto Nazionale di Fisica Nucleare (INFN) in Italy. Bare, isotopically enriched, high purity germanium detectors are operated in liquid argon. GERDA follows a staged approach. In Phase II 35.6 kg of enriched germanium detectors are operated since December 2015. The application of active background rejection methods, such as a liquid argon scintillation light read-out and pulse shape discrimination of germanium detector signals, allows to reduce the background index to the intended level of 10‑3 cts/(keVṡkgṡyr). No evidence for the 0νββ decay has been found in 23.2 kgṡyr of Phase II data, and together with data from Phase I the up-to-date most stringent half-life limit for this process in 76Ge has been established, at a median sensitivity of 5.8ṡ1025yr the 90% C.L. lower limit is 8.0ṡ1025yr.

  5. The LUCIFER/CUPID-0 demonstrator: searching for the neutrinoless double-beta decay with Zn82Se scintillating bolometers

    Science.gov (United States)

    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. S.; Nastasi, M.; Nisi, S.; Nones, C.; 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.

    2017-09-01

    Future experiments on neutrinoless double beta-decay with the aim of exploring the inverted hierarchy region have to employ detectors with excellent energy resolution and zero background in the energy region of interest. Cryogenic scintillating bolometers turn out to be a suitable candidate since they offer particle discrimination: the dual channel detection of the heat and the scintillation light signal allows for particle identification. In particular such detectors permit for a suppression of α-induced backgrounds, a key-issue for next-generation tonne-scale bolometric experiments. We report on the progress and current status of the LUCIFER/CUPID-0 demonstrator, the first array of scintillating bolometers based on enriched Zn82Se crystals which is expected to start data taking in 2016 and the potential of this detection technique for a future tonne-scale bolometric experiment after CUORE.

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

    Science.gov (United States)

    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.

  7. Limit on the anti nu/sub e/ mass in free molecular tritium beta decay

    International Nuclear Information System (INIS)

    Bowles, T.J.; Wilkerson, J.F.; Browne, J.C.; Maley, M.P.; Robertson, R.G.H.; Knapp, D.A.; Helffrich, J.A.

    1986-01-01

    The question of a nonzero neutrino mass has received considerable attention since the claims of Lyubimov et al in 1980 were published which showed evidence for an electron antineutrino mass between 14 and 46 eV, with a best fit value of 35 eV. However, there are still considerable concerns about possible systematic problems in thier experiment. Many of these concerns revolve around the use of a tritiated valine source, in which the energy given up in final state excitations of the molecule following the veta decay of one of the tritium atoms is comparable to the size of the neutrino mass observed. The effect of these final state effects is difficult to calculate in a molecule as complex as valine. In addition, ionization energy loss and backscattering of the betas in traversing the solid source are appreciable and must be very accurately accounted for. These concerns have led us to carry out an experiment using free molecular tritium as the source material. The final state effects have been accurately calculated for the tritium molecule and the uncertainties in these calculations cannot generate a spurious neutrino mass greater than 1 eV. in addition, the energy loss in the source is small because the source consists of tritium only and there is no backscattering

  8. Energy use of decayed wood; Lahopuun maeaerae, sisaeltoe ja hankintakustannukset

    Energy Technology Data Exchange (ETDEWEB)

    Maekelae, M; Lipponen, K [Metsaeteho Oy, Helsinki (Finland)

    1997-12-01

    A study of the quality, amounts and delivery costs of decayed wood available for possible energy use will be carried out in co-operation by Metsaeteho and Forest Research Institute. The work will consist of the following sub-studies: Quality of decayed wood available for possible energy use, quantities of decayed wood available for possible energy use by municipalities in Western and Southern Finland, harvesting, transport and chipping costs of decayed wood in different delivery alternatives and as a practical example, quantities of decayed wood available for possible energy use in two potential consumption municipalities. (orig.)

  9. Investigation of double beta decay of {sup 100}Mo to excited states of {sup 100}Ru

    Energy Technology Data Exchange (ETDEWEB)

    Arnold, R. [IPHC, UPL, CNRS/IN2P3, F-67037 Strasbourg (France); Augier, C. [LAL, Univ Paris-Sud, CNRS/IN2P3, F-91405 Orsay (France); Barabash, A.S. [ITEP, Institute of Theoretical and Experimental Physics, 117218 Moscow (Russian Federation); Basharina-Freshville, A. [University College London, London WC1E 6BT (United Kingdom); Blondel, S. [LAL, Univ Paris-Sud, CNRS/IN2P3, F-91405 Orsay (France); Blot, S. [University of Manchester, Manchester M13 9PL (United Kingdom); Bongrand, M. [LAL, Univ Paris-Sud, CNRS/IN2P3, F-91405 Orsay (France); Brudanin, V. [JINR, Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Busto, J. [CPPM, Université de Marseille, CNRS/IN2P3, F-13288 Marseille (France); Caffrey, A.J. [Idaho National Laboratory, Idaho Falls, ID 83415 (United States); Čermák, P. [IEAP, Czech Technical University in Prague, CZ-12800 Prague (Czech Republic); Cerna, C. [CENBG, Université Bordeaux, CNRS/IN2P3, F-33175 Gradignan (France); Chapon, A. [LPC Caen, ENSICAEN, Université de Caen, CNRS/IN2P3, F-14050 Caen (France); Chauveau, E. [University of Manchester, Manchester M13 9PL (United Kingdom); Dragounová, L. [National Radiation Protection Institute, CZ-14000 Prague (Czech Republic); Duchesneau, D. [LAPP, Université de Savoie, CNRS/IN2P3, F-74941 Annecy-le-Vieux (France); Durand, D. [LPC Caen, ENSICAEN, Université de Caen, CNRS/IN2P3, F-14050 Caen (France); Egorov, V. [JINR, Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Eurin, G. [LAL, Univ Paris-Sud, CNRS/IN2P3, F-91405 Orsay (France); University College London, London WC1E 6BT (United Kingdom); Evans, J.J. [University of Manchester, Manchester M13 9PL (United Kingdom); and others

    2014-05-15

    Double beta decay of {sup 100}Mo to the excited states of daughter nuclei has been studied using a 600 cm{sup 3} low-background HPGe detector and an external source consisting of 2588 g of 97.5% enriched metallic {sup 100}Mo, which was formerly inside the NEMO-3 detector and used for the NEMO-3 measurements of {sup 100}Mo. The half-life for the two-neutrino double beta decay of {sup 100}Mo to the excited 0{sub 1}{sup +} state in {sup 100}Ru is measured to be T{sub 1/2}=[7.5±0.6(stat)±0.6(syst)]⋅10{sup 20} yr. For other (0ν+2ν) transitions to the 2{sub 1}{sup +}, 2{sub 2}{sup +}, 0{sub 2}{sup +}, 2{sub 3}{sup +} and 0{sub 3}{sup +} levels in {sup 100}Ru, limits are obtained at the level of ∼(0.25–1.1)⋅10{sup 22} yr.

  10. Reply to ''Comment on enhancement of forbidden nuclear beta decay by high-intensity radio-frequency fields''

    International Nuclear Information System (INIS)

    Reiss, H.R.

    1984-01-01

    The negative conclusion in the Comment of Becker, Schlicher, and Scully about electromagnetic enhancement of beta decay is shown to be faulty. They have found an algebraic oversight in my paper, but correction of that oversight yields results strongly resembling the original. Becker, Schlicher, and Scully fail to find this. They then conduct an analysis which is highly implicit and incomplete. In attempting to analyze their very complicated expressions they claim not to find significant electromagnetic effects. Yet they also lose completely the electron retardation term of conventional forbidden beta decay. When they attempt to explain the difference between their results and mine, they misconstrue the momentum-translation technique and end up in a logical contradiction. They attempt also to apply a ''no-go'' theorem applicable only to plane-wave particles to my theory, which is built around the use of bound-state nuclear wave functions. This makes the no-go theorem inapplicable

  11. Limit on Neutrinoless Double Beta Decay of 76Ge by GERDA

    Science.gov (United States)

    Agostini, M.; Allardt, M.; Andreotti, E.; Bakalyarov, A. M.; Balata, M.; Barabanov, I.; Heider, M. Barabè; Barros, N.; Baudis, L.; Bauer, C.; Becerici-Schmidt, N.; Bellotti, E.; Belogurov, S.; Belyaev, S. T.; Benato, G.; Bettini, A.; Bezrukov, L.; Bode, T.; Brudanin, V.; Brugnera, R.; Budjáš, D.; Caldwell, A.; Cattadori, C.; Chernogorov, A.; Cossavella, F.; Demidova, E. V.; Domula, A.; Egorov, V.; Falkenstein, R.; Ferella, A.; Freund, K.; Frodyma, N.; Gangapshev, A.; Garfagnini, A.; Gotti, C.; Grabmayr, P.; Gurentsov, V.; Gusev, K.; Guthikonda, K. K.; Hampel, W.; Hegai, A.; Heisel, M.; Hemmer, S.; Heusser, G.; Hofmann, W.; Hult, M.; Inzhechik, L. V.; Csáthy, J. Janicskó; Jochum, J.; Junker, M.; Kihm, T.; Kirpichnikov, I. V.; Kirsch, A.; Klimenko, A.; 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.; Machado, A. A.; Macolino, C.; Majorovits, B.; Maneschg, W.; Misiaszek, M.; Nemchenok, I.; Nisi, S.; Shaughnessy, C. O.'.; Pandola, L.; Pelczar, K.; Pessina, G.; Pullia, A.; Riboldi, S.; Rumyantseva, N.; Sada, C.; Salathe, M.; Schmitt, C.; Schreiner, J.; Schulz, O.; Schwingenheuer, B.; Schönert, S.; Shevchik, E.; Shirchenko, M.; Simgen, H.; Smolnikov, A.; Stanco, L.; Strecker, H.; Tarka, M.; Ur, C. A.; Vasenko, A. A.; Volynets, O.; von Sturm, K.; Wagner, V.; Walter, M.; Wegmann, A.; Wester, T.; Wojcik, M.; Yanovich, E.; Zavarise, P.; Zhitnikov, I.; Zhukov, S. V.; Zinatulina, D.; Zuber, K.; Zuzel, G.

    The Gerda experiment at the Laboratori Nazionali del Gran Sasso in Italy uses germanium detectors made from material with an enriched 76Ge isotope fraction to search for neutrinoless double beta decay of this nucleus. Applying a blind analysis we find no signal after an exposure of 21.6 kg·yr and a background of about 0.01 cts/(keV·kg·yr). A half-life limit of Tov1/2> 2.1 · 1025 yr (90% C.L.) is extracted. The previous claim of a signal for 76Ge is excluded with 99% probability in a model independent way.

  12. Double beta decay - physics beyond the standard model now, and in future (Genius)

    International Nuclear Information System (INIS)

    Klapdor-Kleingrothaus, H.V.

    1998-01-01

    Nuclear double beta decay provides an extraordinarily broad potential to search for beyond standard model physics, probing already now the TeV scale, on which new physics should manifest itself. These possibilities are reviewed here. First, the results of present generation experiments are presented. The most sensitive one of them - the Heidelberg-Moscow experiment in the Gran Sasso - probes the electron mass now in the sub eV region and will reach a limit of ∝0.1 eV in a few years. Basing to a large extent on the theoretical work of the Heidelberg double beta group in the last two years, results are obtained also for SUSY models (R-parity breaking, sneutrino mass), leptoquarks (leptoquark-Higgs coupling), compositeness, right-handed W boson mass and others. These results are comfortably competitive to corresponding results from high-energy accelerators like TEVATRON, HERA, etc. Second, future perspectives of ββ research are discussed. A new Heidelberg experimental proposal (GENIUS) is presented which would allow to increase the sensitivity for Majorana neutrino masses from the present level of at best 0.1 eV down to 0.01 or even 0.001 eV. Its physical potential would be a breakthrough into the multi-TeV range for many beyond standard models. Its sensitivity for neutrino oscillation parameters would be larger than of all present terrestrial neutrino oscillation experiments and of those planned for the future. (orig.)

  13. First measurement of several $\\beta$-delayed neutron emitting isotopes beyond N=126

    CERN Document Server

    Caballero-Folch, R.; Agramunt, J.; Algora, A.; Ameil, F.; Arcones, A.; Ayyad, Y.; Benlliure, J.; Borzov, I.N.; Bowry, M.; Calvino, F.; Cano-Ott, D.; Cortés, G.; Davinson, T.; Dillmann, I.; Estrade, A.; Evdokimov, A.; Faestermann, T.; Farinon, F.; Galaviz, D.; García, A.R.; Geissel, H.; Gelletly, W.; Gernhäuser, R.; Gómez-Hornillos, M.B.; Guerrero, C.; Heil, M.; Hinke, C.; Knöbel, R.; Kojouharov, I.; Kurcewicz, J.; Kurz, N.; Litvinov, Y.; Maier, L.; Marganiec, J.; Marketin, T.; Marta, M.; Martínez, T.; Martínez-Pinedo, G.; Montes, F.; Mukha, I.; Napoli, D.R.; Nociforo, C.; Paradela, C.; Pietri, S.; Podolyák, Zs.; Prochazka, A.; Rice, S.; Riego, A.; Rubio, B.; Schaffner, H.; Scheidenberger, Ch.; Smith, K.; Sokol, E.; Steiger, K.; Sun, B.; Taín, J.L.; Takechi, M.; Testov, D.; Weick, H.; Wilson, E.; Winfield, J.S.; Wood, R.; Woods, P.; Yeremin, A.

    2016-01-01

    The $\\beta$-delayed neutron emission probabilities of neutron rich Hg and Tl nuclei have been measured together with $\\beta$-decay half-lives for 20 isotopes of Au, Hg, Tl, Pb and Bi in the mass region N$\\gtrsim$126. These are the heaviest species where neutron emission has been observed so far. These measurements provide key information to evaluate the performance of nuclear microscopic and phenomenological models in reproducing the high-energy part of the $\\beta$-decay strength distribution. In doing so, it provides important constraints to global theoretical models currently used in $r$-process nucleosynthesis.

  14. Testing Left-Right extensions of the standard model of electroweak interactions with double-beta decay and LHC measurements

    Science.gov (United States)

    Civitarese, O.; Suhonen, J.; Zuber, K.

    2015-07-01

    The minimal extension of the standard model of electroweak interactions allows for massive neutrinos, a massive right-handed boson WR, and a left-right mixing angle ζ. While an estimate of the light (electron) neutrino can be extracted from the non-observation of the neutrinoless double beta decay, the limits on the mixing angle and the mass of the righthanded (RH) boson may be extracted from a combined analysis of the double beta decay measurements (GERDA, EXO-200 and KamLAND-Zen collaborations) and ATLAS data on the two-jets two-leptons signals following the excitation of a virtual RH boson mediated by a heavy-mass neutrino. In this work we shall compare results of both types of experiments, and show that the estimates are not in tension.

  15. Measurements of beta-decay half-lives of short-lived nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Hirose, T.; Tsurita, Y.; Yamamoto, H.; Kawade, K. [Nagoya Univ. (Japan); Iida, T.; Takahashi, A.; Kasugai, Y.; Ikeda, Y.

    1997-03-01

    The {beta}-decay half-lives of short-lived nuclei produced by 14 MeV neutron bombardments were measured with Ge detectors, a High-rate spectroscopy amplifier (EG and G ORTEC model 973) and a Spectrum multi-scaler (Laboratory equipment corporation SMS-48) in the multi-scaling mode. The adequate corrections for pile-up and dead-time losses were made by applying source and pulser methods. The half-lives of {sup 53}V, {sup 53g}Fe, {sup 89m}Y and {sup 162}Tb were determined with uncertainties of 0.13-0.65%. It has been shown that previous values shorter than 10 min were systematically longer than the present ones. (author)

  16. Energy Distributions from Three-Body Decaying Many-Body Resonances

    International Nuclear Information System (INIS)

    Alvarez-Rodriguez, R.; Jensen, A. S.; Fedorov, D. V.; Fynbo, H. O. U.; Garrido, E.

    2007-01-01

    We compute energy distributions of three particles emerging from decaying many-body resonances. We reproduce the measured energy distributions from decays of two archetypal states chosen as the lowest 0 + and 1 + resonances in 12 C populated in β decays. These states are dominated by sequential, through the 8 Be ground state, and direct decays, respectively. These decay mechanisms are reflected in the ''dynamic'' evolution from small, cluster or shell-model states, to large distances, where the coordinate or momentum space continuum wave functions are accurately computed

  17. Special features of the inverse-beta-decay reaction proceeding on a proton in a reactor-antineutrino flux

    Energy Technology Data Exchange (ETDEWEB)

    Kopeikin, V. I., E-mail: kopeikin46@yandex.ru; Skorokhvatov, M. D., E-mail: skorokhvatov-md@nrcki.ru [National Research Center Kurchatov Institute (Russian Federation)

    2017-03-15

    The evolution of the reactor-antineutrino spectrum and the evolution of the spectrum of positrons from the inverse-beta-decay reaction in the course of reactor operation and after reactor shutdown are considered. The present-day status in determining the initial reactor-antineutrino spectrum on the basis of spectra of beta particles from mixtures of products originating from uranium and plutonium fission is described. A local rise of the experimental spectrum of reactor antineutrinos with respect to the expected spectrum is studied.

  18. Preliminary work on the measurement of the {beta} - {nu} angular correlation in the {sup 6}He beta decay by means of a Paul's trap; Etudes et tests preliminaires a une mesure de la correlation angulaire {beta} - {nu} dans la desintegration du noyau {sup 6}He a l'aide d'un piege de Paul

    Energy Technology Data Exchange (ETDEWEB)

    Delahaye, P

    2002-03-01

    The subject of this thesis is the preparation of a measurement of the {beta} - {nu} angular correlation coefficient, in {sup 6}He nuclear {beta} - decay, using a Paul trap. Its principle consists in studying the decay of radioactive ions trapped in a small volume, practically at rest in the center of a transparent electric trap. The trajectories of the particles emitted in the decay are weakly disturbed. The detection in coincidence of the electron and the recoil ion in each decay allows the measurement of 3 observables: the energies of the particles and their relative angle. The {beta} - {nu} angular correlation parameter deduced from the coincidence spectrum is sensitive to the existence of exotic interactions excluded by the V - A theory of the weak interactions. In the case of {sup 6}He decay a deviation observed on the predicted value would imply the existence of tensor type interactions, which might be due to the exchange of leptoquarks. These are gauge bosons present in many extensions of the Standard Model. The work presented here concerns the tests of a transparent Paul trap. The performance of the trap has been tested with ions created in a laser plasma source (Mo{sup +}, Fe{sup +}, Al{sup +}), and also with ions delivered by an ionization source ({sup 4}He{sup +} ions). These experiments were carried out in parallel with their simulations which required the development of a computer code of the electrical potential in various geometries, and of a code of ions transport in the associated fields. These simulations showed a good agreement with the experiment. A Monte Carlo simulation of the experimental setup, for the {beta} - {nu} angular correlation measurement, was then carried out. The distortions of the spectra associated with the varying electric fields in the vicinity of the trap and with the ion cloud size were estimated for various geometries. The statistical needs for the experiment were evaluated in order to reach the required precision. (author)

  19. Measurement of Time-Dependent CP-Violating Asymmetriesand Constraints on sin(2 beta+gamma) withPartial Reconstruction of B to D*-+pi+- Decays

    Energy Technology Data Exchange (ETDEWEB)

    Aubert, B.

    2005-04-19

    We present a measurement of the time-dependent CP-violating asymmetries in decays of neutral B mesons to the final states D*{sup {-+}}{pi}{sup {+-}}, using approximately 232 million B{bar B} events recorded by the BABAR experiment at the PEP-II e{sup +}e{sup -} storage ring. Events containing these decays are selected with a partial reconstruction technique, in which only the high-momentum {pi}{sup {+-}} from the B decay and the low-momentum {pi}{sup {-+}} from the D*{sup {-+}} decay are used. We measure the parameters related to 2{beta} + {gamma} to be a{sub D*{pi}} = -0.034 {+-} 0.014 {+-} 0.009 and c{sub D*{pi}}{sup {ell}} = -0.019 {+-} 0.022 {+-} 0.013. With some theoretical assumptions, we interpret our results in terms of the lower limits |sin(2{beta} + {gamma})| > 0.62 (0.35) at 68% (90%) confidence level.

  20. Comparisons of experimental beta-ray spectra important to decay heat predictions with ENSDF [Evaluated Nuclear Structure Data File] evaluations

    International Nuclear Information System (INIS)

    Dickens, J.K.

    1990-03-01

    Graphical comparisons of recently obtained experimental beta-ray spectra with predicted beta-ray spectra based on the Evaluated Nuclear Structure Data File are exhibited for 77 fission products having masses 79--99 and 130--146 and lifetimes between 0.17 and 23650 sec. The comparisons range from very poor to excellent. For beta decay of 47 nuclides, estimates are made of ground-state transition intensities. For 14 cases the value in ENSDF gives results in very good agreement with the experimental data. 12 refs., 77 figs., 1 tab

  1. Determination of the ratio of axial-vector-to-vector weak coupling constants for beta decay of triton

    CERN Document Server

    Akulov, Y A

    2002-01-01

    Data on the chemical shifts of half-lives for atomic and molecular tritium were used to determine the ratio of axial-vector-to-vector weak coupling constants for beta decay of triton (G sub A /G sub V) sub t = -1.2646 +- 0.0035

  2. Experiments to determine the rate of beta energy release following fission of Pu239 andU235 in a fast reactor

    International Nuclear Information System (INIS)

    Murphy, M.F.; Taylor, W.H.; Sweet, D.W.; March, M.R.

    1979-02-01

    Measurements have been made of the rate of beta energy release from Pu239 and U235 fission fragments over a period of 107 seconds following a 105 second irradiation in the zero-power fast reactor Zebra. Results are compared with predictions using the UKFPDD-1 decay data file and two different sets of fission product yield data. (author)

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

    Science.gov (United States)

    Elliott, S. R.; Abgrall, N.; Aguayo, E.; Avignone, F. T., III; Barabash, A. S.; Bertrand, F. E.; Boswell, M.; Brudanin, V.; Busch, M.; Caldwell, A. S.; Chan, Y.-D.; Christofferson, C. D.; Combs, D. C.; Detwiler, J. A.; Doe, P. J.; Efremenko, Yu.; Egorov, V.; Ejiri, H.; 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.; Leviner, L. E.; Loach, J. C.; MacMullin, S.; Martin, R. D.; Mertens, S.; Mizouni, L.; Nomachi, M.; Orrell, J. L.; O'Shaughnessy, C.; Overman, N. R.; Phillips, D. G., II; Poon, A. W. P.; Pushkin, K.; Radford, D. C.; Rielage, K.; Robertson, R. G. H.; Ronquest, M. C.; Schubert, A. G.; Shanks, B.; Shima, T.; Shirchenko, M.; Snavely, K. J.; Snyder, N.; Soin, A.; Strain, J.; Suriano, A. M.; Timkin, V.; Tornow, W.; Varner, R. L.; Vasilyev, S.; Vetter, K.; Vorren, K.; White, B. R.; Wilkerson, J. F.; Xu, W.; Yakushev, E.; Young, A. R.; Yu, C.-H.; Yumatov, V.

    2013-12-01

    The Majorana collaboration is searching for neutrinoless double beta decay using 76Ge, 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 76Ge. 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.

  4. New physics in the new millennium with GENIUS: double beta decay, dark matter, solar neutrinos

    International Nuclear Information System (INIS)

    Klapdor-Kleingrothaus, H.V.

    2001-01-01

    Double beta decay is indispensable to solve the question of the neutrino mass matrix together with ν oscillation experiments. The most sensitive experiment since eight years - the HEIDELBERG - MOSCOW experiment in Gran Sasso - already now, with the experimental limit of ν > 7 Be) solar neutrinos. A GENIUS Test Facility has just been funded and will come into operation by the end of 2001

  5. MaGe: a Monte Carlo framework for the Gerda and Majorana double beta decay experiments

    International Nuclear Information System (INIS)

    Bauer, M; Belogurov, S; Chan, Yd; Descovich, M; Detwiler, J; Di Marco, M; Fujikawa, B; Franco, D; Gehman, V; Henning, R; Hudek, K; Johnson, R; Jordan, D; Kazkaz, K; Klimenko, A; Knapp, M; Kroeninger, K; Lesko, K; Liu, X; Marino, M; Mokhtarani, A; Pandola, L; Perry, M; Poon, A; Radford, D; Tomei, C; Tull, C

    2006-01-01

    The Gerda and Majorana projects, both searching for the neutrinoless double beta-decay of 76 Ge, are developing a joint Monte-Carlo simulation framework called MaGe. Such an approach has many benefits: the workload for the development of general tools is shared between more experts, the code is tested in more detail, and more experimental data is made available for validation

  6. Plasma resistance behavior during the linear decay phase of RFPs in ETA BETA II

    International Nuclear Information System (INIS)

    Nalesso, G.F.

    1982-01-01

    In the aided-reversal mode RFP discharges produced in ETA BETA II, the plasma current is characterized by a linear decay phase, which follows an approximately exponential phase. During the same period the measured toroidal voltage is negative and initially increasing in absolute value (exponential phase) and then decreasing to almost zero during the linear phase before the current termination. The same behavior of the current has been observed in the quiescent phase in Zeta where a negative toroidal electric field was also observed. In this note we present a model that can explain the linear decay phase and fits with the experimental parameters and allows us to estimate the plasma resistance behavior during the linear phase of slow reversed field pinch discharges

  7. Monte Carlo Simulation for the Majorana Neutrinoless Double-beta Decay Experiment

    International Nuclear Information System (INIS)

    Henning, Reyco; Majorana Collaboration

    2005-01-01

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

  8. Simulation of complex detection systems in neutrinoless double beta decay experiments

    International Nuclear Information System (INIS)

    Larrea, A.; Morales, A.; Morales, J.; Nunez-Lagos, R.; Puimedon, J.; Villar, J.A.

    1988-01-01

    The estimated efficiency of several detection systems dedicated to the search of the neutrinoless double beta decay of 76 Ge is reported. In order to perform this work, we have developed the GEOM macro library system which can handle highly complex geometries in simulation problems, allowing to include an accurate description of the experimental setup in a very simple way. Also an internal mechanism for checking the correct location of every boundary defining the geometrical regions is included. The present version of GEOM is implemented in the EGS4 code of Monte Carlo simulation of photons and electron/positron showers, but it can be easily extended to other simulation codes. (orig.)

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

    Directory of Open Access Journals (Sweden)

    Moggi N.

    2015-01-01

    Full Text Available 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. A Measurement of the CP Parameter sine two beta Using Fully Reconstructed B to ccbar Decays at the BABAR Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Charles, Eric A

    2003-04-22

    This dissertation presents a measurement of the time-dependent CP-violating asymmetries in the neutral B-meson system performed with data collected with the BABAR detector at the PEP-II asymmetric-energy B Factory at the Stanford Linear Accelerator Center. The data sample used consists of 29.7 fb{sup -1} collected at the {Upsilon}(4S) resonance and 3.9 fb{sup -1} collected off-resonance. We analyze three samples of fully-reconstructed B-meson decays: a sample of decays to CP eigenstates in the modes J/{psi} K{sub s}{sup 0}, {psi}(2S) K{sub s}{sup 0}, {chi}{sub cl} K{sub s}{sup 0}, and J/{psi} K*{sup 0} (822 events); as well as both charged (14304 events) and neutral (10457 events) B decays to flavor-eigenstates including D{sup (*)} and {pi}/{rho}/{alpha}{sub 1}. In all cases, the proper decay time difference between the reconstructed B-meson and the recoiling B-meson is determined by measuring the separation of the two decay vertices. Furthermore, the flavor of the recoiling B-meson is tagged using a neural network algorithm. We use the flavor-eigenstate samples to calibrate both the vertexing and tagging performance. We measure the amplitude of the CP asymmetry, sin2{beta} = 0.61 {+-} 0.14(stat) {+-} 0.06(syst). These results indicate the existence of indirect CP violation in the B-meson system.

  11. Energy Decay Laws in Strongly Anisotropic Magnetohydrodynamic Turbulence

    International Nuclear Information System (INIS)

    Bigot, Barbara; Galtier, Sebastien; Politano, Helene

    2008-01-01

    We investigate the influence of a uniform magnetic field B 0 =B 0 e parallel on energy decay laws in incompressible magnetohydrodynamic (MHD) turbulence. The nonlinear transfer reduction along B 0 is included in a model that distinguishes parallel and perpendicular directions, following a phenomenology of Kraichnan. We predict a slowing down of the energy decay due to anisotropy in the limit of strong B 0 , with distinct power laws for energy decay of shear- and pseudo-Alfven waves. Numerical results from the kinetic equations of Alfven wave turbulence recover these predictions, and MHD numerical results clearly tend to follow them in the lowest perpendicular planes

  12. Nuclear transparency and double beta decay of molybdenum 100. Annual report, February 1, 1995 - January 31, 1996

    International Nuclear Information System (INIS)

    Nicholson, H.W.

    1995-07-01

    This report describes progress in data analysis for a search for neutrinoless double-beta decay of molybdenum 100 and related work, Brookhaven National Laboratory's Experiment 850 on color transparency, and work on Brookhaven's EVA detector and the Stanford Linear Accelerator Center's B factory experiment. 6 refs

  13. The Majorana Zero-Neutrino Double-Beta Decay Experiment White Paper

    International Nuclear Information System (INIS)

    Gaitskell, R.; Barabash, A.; Konovalov, S.; Stekhanov, V.; Umatov, V.; Brudanin, V.; Egorov, S.; Webb, J.; Miley, Harry S.; Aalseth, Craig E.; Anderson, Dale N.; Bowyer, Ted W.; Brodzinski, Ronald L.; Jordan, David B.; Kouzes, Richard T.; Smith, Eric E.; Thompson, Robert C.; Warner, Ray A.; Tornow, W.; Young, A.; Collar, J.I.; Avignone, Frank T.; Palms, John M.; Doe, P J.; Elliott, Steven R.; Kazkaz, K.; Robertson, Hamish; Wilkerson, John

    2002-01-01

    The goal of the Majorana Experiment is to determine the effective Majorana mass of the electron neutrino. Detection of the neutrino mass implied by oscillation results in within our grasp. This exciting physics goal is best pursued using double-beta decay of germanium because of the historical and emerging advances in eliminating competing signals from radioactive backgrounds. The Majorana Experiment will consist of a large mass of 76Ge in the form of high-resolution detectors deep underground, searching for a sharp peak at the BB endpoint. We present here an overview of the entire project in order to help put in perspective the scope, the level and technical risk, and the readiness of the Collaboration to begin the undertaking

  14. Beta decay and magnetic moments as tools to probe nuclear structure. Study of neutron-rich nuclei around N=40; Decroissance beta et moments magnetiques comme outils pour sonder la structure nucleaire. Etude des noyaux riches en neutrons autour de N=40

    Energy Technology Data Exchange (ETDEWEB)

    Matea, I

    2003-12-01

    The evolution of nuclear structure in nuclei far from the {beta} stability line is one of the 'hot topics' in modern experimental and theoretical nuclear physics. The present thesis is devoted to the study of structure of neutron-rich nuclei around N=40. The evolution of the neutron g9/2 orbital with increasing number of neutrons is one of the key points defining the structure of these nuclei at low excitation energy. We used for this investigation as experimental tools the magnetic dipole moments measurements and the {beta} decay spectroscopy. For the measurement of the gyromagnetic factor of the 9/2{sup +} isomeric state in Fe{sup 61} we have applied the TDPAD method. This method (like most of measurements of nuclear moments) requires an oriented ensemble of nuclei. The orientation of Fe{sup 61m} was achieved via the fragmentation of Ni{sup 64} at 55 MeV/u and the selection of the fragment momentum with the LISE spectrometer at GANIL. The experimental device was specially conceived to preserve the alignment up to the implantation point. The measured value of the g factor was compared with large-scale shell model and Hartree-Fock-Bogoliubov model predictions. The nuclei studied via {beta} decay were produced by the fragmentation of Kr{sup 86} at 58 MeV/u. For the selection of reaction products we used for the first time the LISE2000 spectrometer and for the detection of {gamma} rays four EXOGAM clover detectors. We measured 5 new lifetimes and 4 lifetimes with a higher precision. From the prompt {beta}{gamma} coincidences we identified new states in the daughter nuclei, as it is the case of the first 2{sup +} excited states in Fe{sup 68} and Ni{sup 72}. The results were compared with the predictions of the large-scale shell model. Other transitions were observed for the first time in {beta}{gamma} decay of Ti{sup 60}, Fe{sup 70} and Co{sup 71,73}. (author)

  15. 'aspect' - a new spectrometer for the measurement of the angular correlation coefficient a in neutron beta decay

    CERN Document Server

    Zimmer, O; Grinten, M G D; Heil, W; Glück, F

    2000-01-01

    The combination of the coefficient a of the antineutrino/electron angular correlation with the beta asymmetry of the neutron provides a sensitive test for scalar and tensor contributions to the electroweak Lagrangian, as well as for right-handed currents. A method is given for measuring a with high sensitivity from the proton recoil spectrum. The method is based on a magnetic spectrometer with electrostatic retardation potentials such as used for searches of the neutrino mass in tritium beta decay. The spectrometer can also be used for similar studies using radioactive nuclei.

  16. Beta-decay asymmetries in polarized /sup 12/B and /sup 12/N and the G-parity non-conservation

    Energy Technology Data Exchange (ETDEWEB)

    Sugimoto, K [Osaka Univ., Toyonaka (Japan). Dept. of Physics

    1976-07-01

    The decay asymmetries (A) in polarized /sup 12/B and /sup 12/N have been measured as a function of ..beta..-ray energies (E). The coefficients ..cap alpha..sub(-+) in A = -+ P(p/E) (1 + ..cap alpha..sub(-+)E)) have been determined to be ..cap alpha..sub(-) (/sup 12/B) = +(0.31+-0.06)%/MeV and ..cap alpha..sub(+) (/sup 12/N) = -(0.21+-0.07)%/MeV. The experimental value, ..cap alpha..sub(-) - ..cap alpha..sub (+) = (0.52+-0.09)%/MeV, is larger than the prediction according to conservation of vector current which includes no second-class current, (..cap alpha..sub(-) - ..cap alpha..sub(+) CVC approximately equal to 0.27%/MeV, and indicates the existence of the second-class induced-tensor current.

  17. $\\beta$-delayed neutron spectroscopy of $^{130-132}$ Cd isotopes with the ISOLDE decay station and the VANDLE array

    CERN Multimedia

    We propose to use the new ISOLDE decay station and the neutron detector VANDLE to measure the $\\beta$-delayed neutron emission of N=82-84 $^{130-132}$Cd isotopes. The large delayed neutron emission probability observed in a previous ISOLDE measurement is indicative of the Gamow-Teller transitions due to the decay of deep core neutrons. Core Gamow-Teller decay has been experimentally proven in the $^{78}$Ni region for the N>50 nuclei using the VANDLE array. The spectroscopic measurement of delayed neutron emission along the cadmium isotopic chain will allow us to track the evolution of the single particle states and the shell gap.

  18. Two neutrino double-beta decay of 100Mo to the first excited 0+ state in 100Ru

    International Nuclear Information System (INIS)

    Barabash, A.S.; Avignone, F.T. III; Guerard, C.K.; Umatov, V.I.

    1992-06-01

    Double-beta decay from the ground state of 100 Mo to the O + excited state at 1,130.29 keV in 100 Ru has been observed. A sample of 956q of Mo metal powder isotopically enriched to 98.468% of 100 Mo was counted in a Marinelli geometry with a well shielded, ultralow-background germanium detector. The cascade gamma-rays at 539.53 and 590.76 keV were observed. The resulting decay half-life is 1.1 -0.2 +0.3 x 10 21 y at 68% CL

  19. Search for new physics in a precise 20F beta spectrum shape measurement

    Science.gov (United States)

    George, Elizabeth; Voytas, Paul; Chuna, Thomas; Naviliat-Cuncic, Oscar; Gade, Alexandra; Hughes, Max; Huyan, Xueying; Liddick, Sean; Minamisono, Kei; Paulauskas, Stanley; Weisshaar, Dirk; Ban, Gilles; Flechard, Xavier; Lienard, Etienne

    2015-10-01

    We are carrying out a measurement of the shape of the energy spectrum of β particles from 20F decay. We aim to achieve a relative precision below 3%, representing an order of magnitude improvement compared to previous experiments. This level of precision will enable a test of the so-called strong form of the conserved vector current (CVC) hypothesis, and should also enable us to place competitive limits on the contributions of exotic tensor couplings in beta decay. In order to control systematic effects, we are using a technique that takes advantage of high energy radioactive beams at the NSCL to implant the decaying nuclei in a scintillation detector deep enough that the emitted beta particles cannot escape. The β-particle energy is measured with the implantation detector after switching off the beam implantation. Ancillary detectors are used to tag the 1.633-MeV γ-rays following the β decay for coincidence measurements in order to reduce backgrounds. We will give an overview and report on the status of the experiment.

  20. Spectroscopy of the doubly magic nucleus 100Sn and its decay

    International Nuclear Information System (INIS)

    Hinke, Christoph B.

    2010-01-01

    The nucleus 100 Sn has been the aim of a number of experimental approaches. It is of great interest for various reasons. It is presumably the heaviest particle-stable N=Z nucleus and at the same time doubly magic. Its beta decay is of particular importance because it is expected to be the purest Gamow-Teller decay in the nuclear chart and thus allows to study the question of the missing Gamow-Teller strength/the Gamow-Teller quenching due to core polarisation effects. From the beta-coincident decay spectroscopy of the daughter nucleus 100 In information about the proton-neutron interaction in this region of the nuclear chart can be obtained. Simultaneously with the implantation of the nucleus in the detector setup after production the search for delayed gamma radiation from a predicted isomeric state in 100 Sn could yield first insight into the structure of excited states in this exotic nucleus. This work presents investigation results concerning the spectroscopy of the doubly magic nucleus 100 Sn and its decay. The experiment was performed in March 2008 at the accelerator facilities of the GSI Helmholtz Zentrum Darmstadt. The neutron deficient nucleus was produced in a projectile fragmentation reaction of a 124 Xe primary beam impinging on a Beryllium target with an energy of 1 GeV x A. After a separation from other fragmentation products and a unique identification 100 Sn was stopped in an implantation detector consisting of highly segmented silicon strip detectors for decay spectroscopy. Beside the determination of the half life it was possible to detect the total energy of the emitted particle radiation in the implantation detector as well as the emitted gamma radiation with a surrounding array of Germanium detectors. With a number of approximately 70 successfully observed decays of 100 Sn a half life of T 1/2 =1.16±0.20s was obtained. The beta endpoint energy of the single channel decay yielded a value of E β 0 =3.29±0.20 MeV. The resultant Gamow

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

    Energy Technology Data Exchange (ETDEWEB)

    Irastorza, I.G.; Aznar, F.; Castel, J., E-mail: igor.irastorza@cern.ch, E-mail: faznar@unizar.es, E-mail: jfcastel@unizar.es [Grupo de Física Nuclear y Astropartículas, Departamento de Física Teórica, Universidad de Zaragoza, C/ P. Cerbuna 12, Zaragoza, 50009 (Spain); 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

  2. Multiple particle emission after 11Li beta-decay: exploring new decay channels

    International Nuclear Information System (INIS)

    Madurga, M.; Borge, M. J. G.; Fynbo, H. O. U.; Prezado, Y.; Tengblad, O.; Jonson, B.; Nyman, G.; Riisager, K.

    2007-01-01

    We present here a study of the three-body, nα 6 He particle break-up of 11 Be(10.6) following 11 Li β-decay. The emitted charged particles were detected in coincidence using a cubic set-up of highly segmented silicon detectors, allowing us to measure simultaneously energy and trajectory. The three body break-up of 11 Be(10.5) through the intermediate state 10 Be(9.6) was modeled using the multiple-level single-channel R-Matrix formalism

  3. Spectroscopy of the doubly magic nucleus {sup 100}Sn and its decay

    Energy Technology Data Exchange (ETDEWEB)

    Hinke, Christoph B.

    2010-07-23

    The nucleus {sup 100}Sn has been the aim of a number of experimental approaches. It is of great interest for various reasons. It is presumably the heaviest particle-stable N=Z nucleus and at the same time doubly magic. Its beta decay is of particular importance because it is expected to be the purest Gamow-Teller decay in the nuclear chart and thus allows to study the question of the missing Gamow-Teller strength/the Gamow-Teller quenching due to core polarisation effects. From the beta-coincident decay spectroscopy of the daughter nucleus {sup 100}In information about the proton-neutron interaction in this region of the nuclear chart can be obtained. Simultaneously with the implantation of the nucleus in the detector setup after production the search for delayed gamma radiation from a predicted isomeric state in {sup 100}Sn could yield first insight into the structure of excited states in this exotic nucleus. This work presents investigation results concerning the spectroscopy of the doubly magic nucleus {sup 100}Sn and its decay. The experiment was performed in March 2008 at the accelerator facilities of the GSI Helmholtz Zentrum Darmstadt. The neutron deficient nucleus was produced in a projectile fragmentation reaction of a {sup 124}Xe primary beam impinging on a Beryllium target with an energy of 1 GeV x A. After a separation from other fragmentation products and a unique identification {sup 100}Sn was stopped in an implantation detector consisting of highly segmented silicon strip detectors for decay spectroscopy. Beside the determination of the half life it was possible to detect the total energy of the emitted particle radiation in the implantation detector as well as the emitted gamma radiation with a surrounding array of Germanium detectors. With a number of approximately 70 successfully observed decays of {sup 100}Sn a half life of T{sub 1/2}=1.16{+-}0.20s was obtained. The beta endpoint energy of the single channel decay yielded a value of E{sub {beta

  4. Search for the Decay B^0 -> a^\\pm_1 \\rho^\\mp

    Energy Technology Data Exchange (ETDEWEB)

    Aubert, B.

    2006-05-10

    The authors present a search for the rare B-meson decay B{sup 0} {yields} {alpha}{sub 1}{sup {+-}}{rho}{sup {-+}} with {alpha}{sub 1}{sup {+-}} {yields} {pi}{sup +}{pi}{sup -}{pi}{sup {+-}}. We use (110 {+-} 1.2) x 10{sup 6} {Upsilon}(4S) {yields} B{bar B} decays collected with the BABAR detector at the PEp-II asymmetric-energy B Factory at SLAC. They obtain an upper limit of 30 x 10{sup -6} (90% C.L.) for the branching fraction product {Beta}(B{sup 0} {yields} {alpha}{sub 1}{sup {+-}}{rho}{sup {-+}}) {Beta}({alpha}{sub 1}{sup {+-}} {yields} {pi}{sup +}{pi}{sup -}{pi}{sup {+-}}), where they assume that the {alpha}{sub 1}{sup {+-}} decays exclusively to {rho}{sup 0}{pi}{sup {+-}}.

  5. Neutrinoless double beta decay search for 130Te: cuoricino status and cuore prospects

    International Nuclear Information System (INIS)

    Sangiorgio, S.; Artusa, D.R.; And others

    2006-01-01

    CUORE is a ∼ I-ton experiment to search for Neutrinoless Double Beta Decay of 130 Te using 988 TeO 2 bolometers. It aims at reaching a sensitivity of the order of few tens of MeV on the effective neutrino mass. CUORICINO, a single CUORE tower running since 2003 in the Gran Sasso Underground Laboratory (LNGS), plays an important role as a standing alone experiment and for developing the future CUORE setup. Present results already achieved and studies that are underway are presented and discussed

  6. Triton beta decay

    International Nuclear Information System (INIS)

    Saito, T.Y.; Wu, Y.; Ishikawa, S.; Sasakawa, T.

    1990-01-01

    Triton β-decay has been calculated using wave functions for 3 He and 3 H obtained from (Coulomb-modified) Faddeev equations for various interactions. We get a value for the Gamow-Teller matrix element of √3 (0.962±0.002) without regards to two- or three-nucleon inteactions. This value agrees with the experimental value. (orig.)

  7. Measurement of the CP-Violating Phase beta_s in B0s -> J/Psi Phi Decays with the CDF II Detector

    Energy Technology Data Exchange (ETDEWEB)

    Aaltonen, T. [Helsinki Institute of Physics (Finland); et al.

    2012-04-01

    We present a measurement of the \\CP-violating parameter \\betas using approximately 6500 $\\BsJpsiPhi$ decays reconstructed with the CDF\\,II detector in a sample of $p\\bar p$ collisions at $\\sqrt{s}=1.96$ TeV corresponding to 5.2 fb$^{-1}$ integrated luminosity produced by the Tevatron Collider at Fermilab. We find the \\CP-violating phase to be within the range $\\betas \\in [0.02, 0.52] \\cup [1.08, 1.55]$ at 68% confidence level where the coverage property of the quoted interval is guaranteed using a frequentist statistical analysis. This result is in agreement with the standard model expectation at the level of about one Gaussian standard deviation. We consider the inclusion of a potential $S$-wave contribution to the $\\Bs\\to J/\\psi K^+K^-$ final state which is found to be negligible over the mass interval $1.009 < m(K^+K^-)<1.028 \\gevcc$. Assuming the standard model prediction for the \\CP-violating phase \\betas, we find the \\Bs decay width difference to be $\\deltaG = 0.075 \\pm 0.035\\,\\textrm{(stat)} \\pm 0.006\\,\\textrm{(syst)} \\ps$. We also present the most precise measurements of the \\Bs mean lifetime $\\tau(\\Bs) = 1.529 \\pm 0.025\\,\\textrm{(stat)} \\pm 0.012\\,\\textrm{(syst)}$ ps, the polarization fractions $|A_0(0)|^2 = 0.524 \\pm 0.013\\,\\textrm{(stat)} \\pm 0.015\\,\\textrm{(syst)}$ and $|A_{\\parallel}(0)|^2 = 0.231 \\pm 0.014\\,\\textrm{(stat)} \\pm 0.015\\,\\textrm{(syst)}$, as well as the strong phase $\\delta_{\\perp}= 2.95 \\pm 0.64\\,\\textrm{(stat)} \\pm 0.07\\,\\textrm{(syst)} \\textrm{rad}$. In addition, we report an alternative Bayesian analysis that gives results consistent with the frequentist approach.

  8. Q value for the 34Cl superallowed beta decay

    International Nuclear Information System (INIS)

    Lin, S.; Brindhaban, S.A.; Barker, P.H.

    1994-01-01

    The proton separation energy of 34 Cl has been measured to be 5143.30(5) keV in a series of overlapping and self-consistent experiments involving the study of three resonances in the 33 S(p,γ) reaction, using a variety of techniques in laboratories in Auckland and Florence. This figure is in disagreement with the only other published value. By combining the proton separation energy with the only measured value for the 34 S neutron separation energy, the Q ec for the 34 Cl superallowed decay becomes 5491.48(12) keV. Some comments are offered on the associated 34 S(p,n) 34 Cl threshold energy measurement

  9. The NUMEN project: NUclear Matrix Elements for Neutrinoless double beta decay

    Science.gov (United States)

    Cappuzzello, F.; Agodi, C.; Cavallaro, M.; Carbone, D.; Tudisco, S.; Lo Presti, D.; Oliveira, J. R. B.; Finocchiaro, P.; Colonna, M.; Rifuggiato, D.; Calabretta, L.; Calvo, D.; Pandola, L.; Acosta, L.; Auerbach, N.; Bellone, J.; Bijker, R.; Bonanno, D.; Bongiovanni, D.; Borello-Lewin, T.; Boztosun, I.; Brunasso, O.; Burrello, S.; Calabrese, S.; Calanna, A.; Chávez Lomelí, E. R.; D'Agostino, G.; De Faria, P. N.; De Geronimo, G.; Delaunay, F.; Deshmukh, N.; Ferreira, J. L.; Fisichella, M.; Foti, A.; Gallo, G.; Garcia-Tecocoatzi, H.; Greco, V.; Hacisalihoglu, A.; Iazzi, F.; Introzzi, R.; Lanzalone, G.; Lay, J. A.; La Via, F.; Lenske, H.; Linares, R.; Litrico, G.; Longhitano, F.; Lubian, J.; Medina, N. H.; Mendes, D. R.; Moralles, M.; Muoio, A.; Pakou, A.; Petrascu, H.; Pinna, F.; Reito, S.; Russo, A. D.; Russo, G.; Santagati, G.; Santopinto, E.; Santos, R. B. B.; Sgouros, O.; da Silveira, M. A. G.; Solakci, S. O.; Souliotis, G.; Soukeras, V.; Spatafora, A.; Torresi, D.; Magana Vsevolodovna, R.; Yildirim, A.; Zagatto, V. A. B.

    2018-05-01

    The article describes the main achievements of the NUMEN project together with an updated and detailed overview of the related R&D activities and theoretical developments. NUMEN proposes an innovative technique to access the nuclear matrix elements entering the expression of the lifetime of the double beta decay by cross section measurements of heavy-ion induced Double Charge Exchange (DCE) reactions. Despite the fact that the two processes, namely neutrinoless double beta decay and DCE reactions, are triggered by the weak and strong interaction respectively, important analogies are suggested. The basic point is the coincidence of the initial and final state many-body wave functions in the two types of processes and the formal similarity of the transition operators. First experimental results obtained at the INFN-LNS laboratory for the 40Ca(18O,18Ne)40Ar reaction at 270MeV give an encouraging indication on the capability of the proposed technique to access relevant quantitative information. The main experimental tools for this project are the K800 Superconducting Cyclotron and MAGNEX spectrometer. The former is used for the acceleration of the required high resolution and low emittance heavy-ion beams and the latter is the large acceptance magnetic spectrometer for the detection of the ejectiles. The use of the high-order trajectory reconstruction technique, implemented in MAGNEX, allows to reach the experimental resolution and sensitivity required for the accurate measurement of the DCE cross sections at forward angles. However, the tiny values of such cross sections and the resolution requirements demand beam intensities much larger than those manageable with the present facility. The on-going upgrade of the INFN-LNS facilities in this perspective is part of the NUMEN project and will be discussed in the article.

  10. Study and conception of the decay ring of a neutrino facility using the β decays of the helium 6 and neon 18 nuclei produced by an intense beam of protons hitting various targets

    International Nuclear Information System (INIS)

    Chance, A.

    2007-09-01

    The study of the neutrino oscillation between its different flavours needs pure and very intense flux of energetic, well collimated neutrinos with a well determined energy spectrum. So, a dedicated machine seems necessary nowadays. Among the different concepts of neutrino facilities, the one which will be studied here, called Beta-Beams, lies on the neutrino production by beta decay of radioactive ions after their acceleration. More precisely, the thesis is focused on the study and the design of the race-track-shaped storage ring of the high energy ions. Its aim is to store the ions until decaying. After a brief description of the neutrino oscillation mechanism and a review of the different experiments, an introduction to the neutrino facility concept and more precisely to the Beta-Beams will be given. Then, the issues linked to the Beta-Beams will be presented. After a description of the beam transport formalism, a first design and the optical properties of the ring will be then given. The effects of the misalignment and of the field errors in the dipoles have been studied. The dynamic aperture optimization is then realized. Handling of the decay losses or the energy collimation scheme will be developed. The off-momentum injection needed in presence of a circulating beam will be explained. Finally, the specific radiofrequency program needed by the beam merging will be presented. (author)

  11. Double beta radioactivity and physics of the neutrino. Study of the background noise at 3 MeV in the search of 100Mo beta beta decay

    International Nuclear Information System (INIS)

    Piquemal, F.

    1994-05-01

    Double beta decay without neutrino emission provides a test of the mass and nature of neutrinos (Majorana or Dirac). Experimental proof would be the observation of a peak at the transition energy in the spectrum of the two emitted electrons. The expected half-life of the process is extremely long (about 10 25 years for 100 Mo). So, being thus, it is very important to get a good knowledge of the origins and contributions of background noise in the region where the signal could occur. The main origins of the background noise in the region where the signal could occur. The main origins of the background noise are found to be e + - e - pairs induced by heavy energy gamma rays. These gamma rays follow the thermal neutron capture by the components of the detector. Another factor in the production of background noise is natural radio-activity. For example, the presence of Radon in the laboratory has been observed to produce deposits of 214 Bi on the sides of the detector. Data taken with the NEMO 2 prototype and an enriched molybdenum source foil indicates that the background limit reached is of the order of 1 event per year in the 3 MeV region. Results of this work have proven the necessity to have a magnetic field in NEMO 3 in order to reject e + - e - pairs. (author)

  12. Results on neutrinoless double beta decay of 76Ge from the GERDA experiment

    Science.gov (United States)

    Palioselitis, Dimitrios

    2015-05-01

    The Germanium Detector Array (GERDA) experiment is searching for neutrinoless double beta (0νββ) decay of 76Ge, a lepton number violating nuclear process predicted by extensions of the Standard Model. GERDA is an array of bare germanium diodes immersed in liquid argon located at the Gran Sasso National Laboratory (LNGS) in Italy. The results of the GERDA Phase I data taking with a total exposure of 21.6 kg yr and a background index of 0.01 cts/(keV kg yr) are presented in this paper. No signal was observed and a lower limit of T1/20ν > 2.1×1025 yr (90% C.L.) was derived for the half-life of the 0νββ decay of 76Ge. Phase II of the experiment aims to reduce the background around the region of interest by a factor of ten.

  13. Simulation of decay processes and radiation transport times in radioactivity measurements

    Energy Technology Data Exchange (ETDEWEB)

    García-Toraño, E., E-mail: e.garciatorano@ciemat.es [Laboratorio de Metrología de Radiaciones Ionizantes, CIEMAT, Avda. Complutense 22, 28040 Madrid (Spain); Peyres, V. [Laboratorio de Metrología de Radiaciones Ionizantes, CIEMAT, Avda. Complutense 22, 28040 Madrid (Spain); Bé, M.-M.; Dulieu, C.; Lépy, M.-C. [CEA, LIST, Laboratoire National Henri Becquerel (LNE-LNHB), Bldg 602, PC111, 91191 Gif-sur-Yvette Cedex (France); Salvat, F. [Facultat de Física (FQA and ICC), Universitat de Barcelona, Diagonal 647, 08028 Barcelona (Spain)

    2017-04-01

    The Fortran subroutine package PENNUC, which simulates random decay pathways of radioactive nuclides, is described. The decay scheme of the active nuclide is obtained from the NUCLEIDE database, whose web application has been complemented with the option of exporting nuclear decay data (possible nuclear transitions, branching ratios, type and energy of emitted particles) in a format that is readable by the simulation subroutines. In the case of beta emitters, the initial energy of the electron or positron is sampled from the theoretical Fermi spectrum. De-excitation of the atomic electron cloud following electron capture and internal conversion is described using transition probabilities from the LLNL Evaluated Atomic Data Library and empirical or calculated energies of released X rays and Auger electrons. The time evolution of radiation showers is determined by considering the lifetimes of nuclear and atomic levels, as well as radiation propagation times. Although PENNUC is designed to operate independently, here it is used in conjunction with the electron-photon transport code PENELOPE, and both together allow the simulation of experiments with radioactive sources in complex material structures consisting of homogeneous bodies limited by quadric surfaces. The reliability of these simulation tools is demonstrated through comparisons of simulated and measured energy spectra from radionuclides with complex multi-gamma spectra, nuclides with metastable levels in their decay pathways, nuclides with two daughters, and beta plus emitters.

  14. Neutrinoless double beta decay in an SU(3)L x U(1)N model

    International Nuclear Information System (INIS)

    Pleitez, V.; Tonasse, M.D.

    1993-01-01

    A model for the electroweak interactions with SU (3) L x U(1) N gauge symmetry is considered. It is shown that, it is the conservation of F = L + B which forbids massive neutrinos and the neutrinoless double beta decay, (β β) On u. Explicit and spontaneous breaking of F imply that the neutrinos have an arbitrary mass and (β β) On u proceeds also with some contributions that do not depend explicitly on the neutrino mass. (author)

  15. Beta decay of 22O

    International Nuclear Information System (INIS)

    Hubert, F.; Dufour, J.P.; Moral, R. Del; Fleury, A.; Jean, D.; Pravikoff, M.S.; Geissel, H.; Schmidt, K.H.; Hanelt, E.

    1991-01-01

    22 O nuclei were produced as fragments of a 60 MeV/n 40 Ar beam interacting with a thick Be target. They were selected from all the produced nuclei with the LISE separator. γ spectra in coincidence with the β decay were measured. Partial decay scheme of 22 O is given. Similarities between experiments and calculations are discussed. (G.P.) 10 refs.; 3 figs

  16. Calibration of radionuclides with decay trough beta emission or electron capture by liquid scintillation technique; Calibracao de radionuclideos que decaem por emissao beta ou por captura eletronica pela tecnica de cintilacao liquida

    Energy Technology Data Exchange (ETDEWEB)

    Loureiro, Jamir dos Santos

    2000-02-01

    In this work is reported a methodology a methodology for pure beta and electron capture radionuclides standardization, suing liquid scintillation technique. In this sense the CIEMAT/NIST method, recently utilized by international laboratories, was implemented and the lack in the Laboratorio Nacional das Radiacoes Ionizantes - LNMRI, of the Comissao Nacional de Energia Nuclear - CNEN, for adequate methodology to standardize this kind if radionuclides was filled, fact that was not present with alpha and gamma radionuclides. The implementation procedure evaluation was provided by concentration activity determination of the following radionuclides: {sup 14} C and {sup 90} Sr, pure beta emitters; {sup 55} Fe, electron capture decay; {sup 204} Tl, electron capture and beta decay and {sup 60} Co, beta-gamma emitter. In this way, a careful analysis of the implementation procedure with these radionuclides types, ranging on a broad energy spectral, was possible. To check the calibration results, intercomparisons among our measurements of these radionuclides and the reference values of the CIEMAT/Spain laboratory were provided. To check the calibration results, intercomparisons among our measurements of these radionuclides and the reference values of the CIEMAT/Spain laboratory were provided. Besides this intercomparisons, one was provided with a {sup 204} Tl solution, utilized in the international comparison recently promoted by BIPM, and another one with a {sup 60} C solution calibrated in LNMRI/CNEN previously by a relative calibration system, with a well type pressurized ionization chamber, and an absolute beta-gamma coincidence system, with a pill-box type proportional counter 4 {pi} geometry, coupled with a scintillator system with a sodium iodide cristal of 4x4 inches. The comparisons among LNMRI/CNEN results and the reference values, showed a small deviation of 1,32% for {sup 14} C, 0,40% for {sup 60} Co, 1,12% for {sup 55} Fe, 0,10% for {sup 90} Sr and 0,73% for {sup

  17. New results for double-beta decay of 100Mo to excited final states of 100Ru using the TUNL-ITEP apparatus

    International Nuclear Information System (INIS)

    Kidd, M.F.; Esterline, J.H.; Tornow, W.; Barabash, A.S.; Umatov, V.I.

    2009-01-01

    The coincidence detection efficiency of the TUNL-ITEP apparatus designed for measuring half-life times of two-neutrino double-beta (2νββ) decay transitions to excited final states in daughter nuclei has been measured with a factor of 2.4 improved accuracy. In addition, the previous measuring time of 455 days for the study of the 100 Mo 2νββ decay to the first excited 0 1 + state in 100 Ru has been increased by 450 days, and a new result (combined with the previous measurement obtained with the same apparatus) for this transition is presented: T 1/2 =[5.5 -0.8 +1.2 (stat)±0.3(syst)]x10 20 yr. Measured 2νββ decay half-life times to excited states can be used to test the reliability of nuclear matrix element calculations needed for determining the effective neutrino mass from zero-neutrino double-beta decay data. We also present new limits for transitions to higher excited states in 100 Ru which, if improved, may be of interest for more exotic conjectures, like a bosonic component to neutrino statistics.

  18. First observation of 109Te β+ and electron capture decay to levels of 109Sb

    International Nuclear Information System (INIS)

    Ressler, J.J.; Walters, W.B.; Shergur, J.; Davids, C.N.; Heinz, A.; Seweryniak, D.; Dean, D.J.; Hjorth-Jensen, M.

    2002-01-01

    Low-spin levels in 109 Sb populated by 109 Te beta decay are reported for the first time. Seven new levels are proposed, two below 1 MeV excitation energy. Spins and parities of (1/2 + ) and (3/2 + ,5/2 + ) are suggested for the low energy levels by comparison to beta feeding intensities and systematics. These results are compared with new calculated levels for 109 Sb

  19. Shape effects in the vicinity of the Z=82 line: study of the $\\beta$-decay of $^{182,184,186}$Hg

    CERN Multimedia

    This proposal is aimed at the study of the $\\beta$-decay of the neutron-­deficient $^{182,184,186}$Hg nuclei using the total absorption technique. Recent theoretical results show that, from measurements of the Gamow-­Teller strength distribution, the shapes of the ground states of the decaying Hg nuclei can be inferred. This study offers an independent way to study the phenomenon of shape coexistence in a region of particular interest.

  20. BETA digital beta radiometer

    International Nuclear Information System (INIS)

    Borovikov, N.V.; Kosinov, G.A.; Fedorov, Yu.N.

    1989-01-01

    Portable transportable digital beta radiometer providing for measuring beta-decay radionuclide specific activity in the range from 5x10 -9 up to 10 -6 Cu/kg (Cu/l) with error of ±25% is designed and introduced into commercial production for determination of volume and specific water and food radioactivity. The device specifications are given. Experience in the BETA radiometer application under conditions of the Chernobyl' NPP 30-km zone has shown that it is convenient for measuring specific activity of the order of 10 -8 Cu/kg, and application of a set of different beta detectors gives an opportunity to use it for surface contamination measurement in wide range of the measured value

  1. Double Beta Decay - Physics Beyond the Standard Model Now, and in Future (GENIUS)

    Science.gov (United States)

    Klapdor-Kleingrothaus, H. V.

    Nuclear double beta decay provides an extraordinarily broad potential to search for beyond Standard Model physics, probing already now the TeV scale, on which new physics should manifest itself. These possibilities are reviewed here. First, the results of present generation experiments are presented. The most sensitive one of them - the Heidelberg-Moscow experiment in the Gran Sasso - probes the electron mass now in the sub eV region and will reach a limit of ˜ 0.1 eV in a few years. Basing to a large extent on the theoretical work of the Heidelberg Double Beta Group in the last two years, results are obtained also for SUSY models (R-parity breaking, sneutrino mass), leptoquarks (leptoquark-Higgs coupling), com-positeness, right-handed W boson mass and others. These results are comfortably competitive to corresponding results from high-energy accelerators like TEVA-TRON, HERA, etc. Second, future perspectives of ʲʲ research are discussed. A new Heidelberg experimental proposal (GENIUS) is presented which would allow to increase the sensitivity for Majorana neutrino masses from the present level of at best 0.1 eV down to 0.01 or even 0.001 eV. Its physical potential would be a breakthrough into the multi-TeV range for many beyond standard models. Its sensitivity for neutrino oscillation parameters would be larger than of all present terrestrial neutrino oscillation experiments and of those planned for the future. It would further, already in a first step, cover almost the full MSSM parameter space for prediction of neutralinos as cold dark matter, making the experiment competitive to LHC in the search for supersymmetry.

  2. Search for the Rare Decays $B^0\\to D_s^{(*)+} a_{0(2)}^-$

    Energy Technology Data Exchange (ETDEWEB)

    Aubert, B.; Barate, R.; Boutigny, D.; Couderc, F.; Karyotakis, Y.; Lees, J.P.; Poireau, V.; Tisserand, V.; Zghiche, A.; /Annecy, LAPP; Grauges, E.; /Barcelona, IFAE; Palano, A.; Pappagallo, M.; Pompili, A.; /Bari U. /INFN, Bari; Chen, J.C.; Qi, N.D.; Rong, G.; Wang, P.; Zhu, Y.S.; /Beijing, Inst. High Energy Phys.; Eigen, G.; Ofte, I.; Stugu, B.

    2006-01-09

    The authors have searched for the decays B{sup 0} {yields} D{sub s}{sup +}a{sub 0}{sup -}, B{sup 0} {yields} D*{sub s}{sup +} a{sub 0}{sup -}, B{sup 0} {yields} D{sub s}{sup +}a{sub 2}{sup -} and B{sup 0} {yields} D*{sub s}{sup +} a{sub 2}{sup -} in a sample of about 230 million {Upsilon}(4S) {yields} B{bar B} decays collected with the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC. They find no evidence for these decays and set upper limits at 90% C.L. on the branching fractions: {Beta}(B{sup 0} {yields} D{sub s}{sup +} a{sub 0}{sup -}) < 1.9 x 10{sup -5}, {Beta}(B{sup 0} {yields} D*{sub s}{sup +} a{sub 0}{sup -}) < 3.6 x 10{sup -5}, {Beta}(B{sup 0} {yields} D{sub s}{sup +} a{sub 2}{sup -}) < 1.9 x 10{sup -4}, and {Beta}(B{sup 0} {yields} D*{sub s}{sup +} a{sub 2}{sup -}) < 2.0 x 10{sup -4}.

  3. A review of superheated superconducting granules as a detector for dark matter, solar neutrinos, monopoles and double beta decay

    International Nuclear Information System (INIS)

    Pretzl, K.P.

    1987-11-01

    The use of superheated superconducting granules as a particle detector is reviewed. Their application for the detection of dark matter, solar neutrinos, monopoles, and double beta decay is described. A status report on the experimental development of these devices is given. (orig.)

  4. 78Kr(α,γ) reaction of astrophysical interest in inverse kinematics and the electronic screening effect on the beta decay

    International Nuclear Information System (INIS)

    Ujic, P.

    2011-12-01

    The thesis is constituted of two different topics related to astrophysics. The titles of these topics are: 'Alpha capture reaction in inverse kinematics, measurement of 78 Kr(α,γ) 82 Sr reaction' and 'Measurement of the radioactive decay of 19 O and 19 Ne implanted in niobium'. The goal of the first part of the thesis was to establish an experimental technique for measuring radiative alpha capture reaction at low energies in inverse kinematics. The measurement of these reactions is very important in astrophysics since it will help to improve the reliability of alpha particle optical model potentials which are used for prediction of cross sections of nuclear reaction used in different astrophysical models of supernovae explosions. In this part we insisted on a technical feasibility of this type of experiment. In the second part of the thesis, we examined the influence of the environment on the beta decay probability, in particular the influence of the electronic screening of Coulomb barrier of nuclei induced by Cooper pairs in superconductors. The indication of an extremely weak effect was noticed. (author)

  5. The beta decay of hyperons

    International Nuclear Information System (INIS)

    Bohm, A.; Garcia, A.; Instituto Politecnico Nacional, Mexico City. Escuela Superior de Fisica y Matematicas); Kielanowski, P.; Texas Univ., Austin; Instituto Politecnico Nacional, Mexico City. Centro de Investigacion y de Estudios Avanzados)

    1985-01-01

    This book is an introduction to the physics of the semileptonic decay of hyperons. After a general introduction and a description of the experimental results the Cabibbo theory is introduced for the theoretical description of these results. Then radiative and other corrections are discussed. Finally this decay is considered in the framework of broken SU(3). This book applies to graduate students and other ''non-specialists'' who want to get some insight into the physics of weak interactions. (HSI)

  6. The 49K beta decay

    International Nuclear Information System (INIS)

    Hansen, P.G.; Huck, A.; Klotz, G.; Knipper, A.; Miehe, C.; Walter, G.; Jonson, B.; Mattsson, S.; Ravn, H.L.; Kratz, K.L.

    1981-01-01

    The decay of 49 K has been studied through neutron and gamma spectroscopy techniques. The 49 K activity was formed by 600 MeV proton fragmentation reactions in a uranium carbide target. The observed β-strength, in addition to the general behaviour expected from the gross theory of β-decay, displays two resonances centered at about 6.5 MeV and 9.5 MeV in 49 Ca. This structure is discussed in simple shell-model terms. (orig.)

  7. Energy spectra of massive two-body decay products and mass measurement

    CERN Document Server

    Agashe, Kaustubh; Hong, Sungwoo; Kim, Doojin

    2016-01-01

    We have recently established a new method for measuring the mass of unstable particles produced at hadron colliders based on the analysis of the energy distribution of a massless product from their two-body decays. The central ingredient of our proposal is the remarkable result that, for an unpolarized decaying particle, the location of the peak in the energy distribution of the observed decay product is identical to the (fixed) value of the energy that this particle would have in the rest-frame of the decaying particle, which, in turn, is a simple function of the involved masses. In addition, we utilized the property that this energy distribution is symmetric around the location of peak when energy is plotted on a logarithmic scale. The general strategy was demonstrated in several specific cases, including both beyond the SM particles, as well as for the top quark. In the present work, we generalize this method to the case of a massive decay product from a two-body decay; this procedure is far from trivial b...

  8. Beta-decay of 56Cu

    International Nuclear Information System (INIS)

    Ramdhane, M.; Baumann, P.; Knipper, A.; Walter, G.; Janas, Z.; Plochocki, A.; Liu, W.; Grawe, H.; Hu, Z.; Kirchner, R.; Klepper, O.; Roeckl, E.; Gorska, M.; Fujita, Y.; Brown, B.A.

    1998-02-01

    By measuring positrons and β-delayed γ-rays emitted from mass-separated sources, the decay of 56 Cu(4 + ,T z =-1,T=1) to states in the doubly-magic nucleus 56 Ni was studied for the first time. The half-life of 56 Cu was measured to be 78(15) ms, and four β-delayed γ-rays were assigned to its decay. The resulting experimental data on Fermi and Gamow-Teller strength are compared with shell-model predictions. (orig.)

  9. Results of a search for the neutrinoless double beta decay of 76Ge to the first excited state of 76Se

    International Nuclear Information System (INIS)

    Morales, A.; Morales, J.; Nunez-Lagos, R.; Puimedon, J.; Villar, J.A.; Larrea, A.

    1988-01-01

    A search for the neutrinoless double beta decay of 76 Ge to the first excited state E=559.1 KeV of 76 Se has been carried out in the Frejus tunnel using a coincidence technique between Ge and NaI detectors. No peak has been observed in the electron energy spectrum at the value of 1482 KeV. That implies a half-life lower limit of 6 x 10 22 years. However the experimental data display a coincidence, at the level of 2.5 σ, between an energy deposition of 1483.7 ± 0.5 KeV in the Ge detector and 558 ± 15 KeV in the NaI detector. The main features of such a coincidence effect are analysed and, in spite of its small statistical significance, its possible interpretation is discussed

  10. Internal Bremsstrahlung accompanying beta decay of 90 Y

    International Nuclear Information System (INIS)

    Elsayed, A.M.A.; Abdelhady, E.E.

    1992-01-01

    The internal Bremsstrahlung (IB) spectrum associated with the unique first-forbidden β decay of 9 0Y is measured employing the conventional β-stopper technique with a 5 x 5 cm NaI (T 1) scintillation spectrometer in the energy range (50-2000 keV). All the necessary corrections are made. In order to analyze the experimental data, a response matrix having the dimensions of 64 energy bins and 474 channels is constructed.with the help of the detector assembly response matrix, the true IB energy spectrum is obtained by iteratively unfolding the experimental pulse-height spectrum. The experimental results are compared with the corresponding theoretical distributions due to Knipp and Uhlenbeck and Bloch (KUB), lewis and ford (L F), and ford and martin (FM). The results show reasonable agreement with the detour theory of ford and martin.3 fig

  11. The Gerda search for neutrinoless double beta decay

    Science.gov (United States)

    O'Shaughnessy, Christopher; Gerda Collaboration

    2013-10-01

    The Germanium Detector Array (Gerda) is a search for the neutrinoless double beta decay of 76Ge. High Purity Germanium (HPGe) detectors enriched in the isotope-76 are operated bare in liquid argon (LAr). LAr is used for both cooling of the HPGe diodes to their operating temperatures and for shielding from external radiation sources. From the measurements of the first phase that began data taking on 1 Nov. 2011 it is expected to have a sensitivity on the level of T1/2>2E25 yr at a 90% CL after 15 kġyr. The goal of this phase will be to probe the claim of an observation by part of the Heidelberg-Moscow collaboration. Efforts will then focus on increasing the sensitivity of the experiment by deploying additional enriched detectors that are in an advanced stage of production and by reducing the background index further by making use of pulse shape discrimination techniques as well as an active LAr veto. While the 0νββ region of interest continues to remain blinded, here the status of Phase-I data taking is presented along with the work towards improving the experimental sensitivity.

  12. Precision measurements in nuclear {beta}-decay with LPCTrap

    Energy Technology Data Exchange (ETDEWEB)

    Ban, Gilles; Durand, Dominique; Flechard, Xavier; Lienard, Etienne [LPC Caen, ENSICAEN, Universite de Caen, CNRS/IN2P3, Caen (France); Naviliat-Cuncic, Oscar [NSCL and Department of Physics and Astronomy, Michigan State University, East-Lansing, MI (United States)

    2013-09-15

    The experimental achievements and the current program with the LPCTrap device installed at the LIRAT beam line of the SPIRAL1-GANIL facility are presented. The device is dedicated to the study of the weak interaction at low energy by means of precise measurements of the {beta}-{nu} angular correlation parameter. Technical aspects as well as the main results are reviewed. The future program with new available beams is briefly discussed. (copyright 2013 by WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  13. Search for Correlated Fluctuations in the Beta+ Decay of Na-22

    Science.gov (United States)

    Silverman, M. P.; Strange, W.

    2008-10-01

    Claims for a ``cosmogenic'' force that correlates otherwise independent stochastic events have been made for at least 10 years, based largely on visual inspection of time series of histograms whose shapes were interpreted as suggestive of recurrent patterns with semi-diurnal, diurnal, and monthly periods. Building on our earlier work to test randomness of different nuclear decay processes, we have searched for correlations in the time-series of coincident positron-electron annihilations deriving from beta+ decay of Na-22. Disintegrations were counted within a narrow time window over a period of 7 days, leading to a time series of more than 1 million events. Statistical tests were performed on the raw time series, its correlation function, and its Fourier transform to search for cyclic correlations indicative of quantum-mechanical violating deviations from Poisson statistics. The time series was then partitioned into a sequence of 167 ``bags'' each of 8192 events. A histogram was made of the events of each bag, where contiguous frequency classes differed by a single count. The chronological sequence of histograms was then tested for correlations within classes. In all cases the results of the tests were in accord with statistical control, giving no evidence of correlated fluctuations.

  14. Nuclear transparency, B physics, and double beta decay. Annual report, February 1, 1996 - January 31, 1997

    International Nuclear Information System (INIS)

    Nicholson, H.W.

    1996-07-01

    This report describes the publication of results of a search for neutrinoless double-beta decay of molybdenum 100 and preparation of a paper on statistical analysis techniques used, developments related to purification techniques for the molybdenum, and other related work; progress in redesign, rebuilding, and installation of the Brookhaven EVA detector's superconducting magnet and cryogenic system; and the testing of detector components for SLAC's BaBar experiment. 3 refs

  15. Calibration of the NEXT-White Detector using $^{83m}\\mathrm{Kr}$ Decays

    Energy Technology Data Exchange (ETDEWEB)

    Martínez-Lema, G.; et al.

    2018-04-05

    The NEXT-White (NEW) detector is currently the largest radio-pure high pressure gas xenon time projection chamber with electroluminescent readout in the world. NEXT-White has been operating at Laboratorio Subterr\\'aneo de Canfranc (LSC) since October 2016. This paper describes the calibrations performed with $^{83m}\\mathrm{Kr}$ decays during a long run taken from March to November 2017 (Run II). Krypton calibrations are used to correct for the finite drift-electron lifetime as well as for the dependence of the measured energy on the event position which is mainly caused by variations in solid angle coverage. After producing calibration maps to correct for both effects we measure an excellent energy resolution for 41.5 keV point-like deposits of (4.55 $\\pm$ 0.01) % FWHM in the full chamber and (3.88 $\\pm$ 0.04) % FWHM in a restricted fiducial volume. Using naive 1/$\\sqrt{E}$ scaling, these values translate into FWHM resolutions of (0.592 $\\pm$ 0.001) % FWHM and (0.504 $\\pm$ 0.005) % at the $Q_{\\beta\\beta}$ energy of xenon double beta decay (2458 keV), well within range of our target value of 1%.

  16. Availability of nuclear decay data in electronic form, including beta spectra not previously published

    International Nuclear Information System (INIS)

    Eckerman, K.F.; Westfall, R.J.; Ryman, J.C.; Cristy, M.

    1994-01-01

    The unabridged data used in preparing ICRP Publication 38 (1983) and a monograph of the Medical Internal Radiation Dose (MIRD) Committee are now available in electronic form. The open-quotes ICRP38 collectionclose quotes contains data on the energies and intensities of radiations emitted by 825 radionuclides (those in ICRP Publication 38 plus 13 from the MIRD monograph), and the open-quotes MIRD collectionclose quotes contains data on 242 radionuclides. Each collection consists of a radiations data file and a beta spectra data file. The radiations data file contains the complete listing of the emitted radiations, their types, mean or unique energies, and absolute intensities for each radionuclide, the probability that a beta particle will be emitted with kinetic energies defined by a standard energy grid. Although summary information from the radiation data files has been published, neither the unabridged data nor the beta spectra have been published. These data files and a data extraction utility, which runs on a personal computer, are available from the Radiation Shielding Information Center at Oak Ridge National Laboratory. 13 refs., 1 fig., 6 tabs

  17. PandaX-III: Searching for neutrinoless double beta decay with high pressure 136Xe gas time projection chambers

    Science.gov (United States)

    Chen, Xun; Fu, ChangBo; Galan, Javier; Giboni, Karl; Giuliani, Franco; Gu, LingHui; Han, Ke; Ji, XiangDong; Lin, Heng; Liu, JiangLai; Ni, KaiXiang; Kusano, Hiroki; Ren, XiangXiang; Wang, ShaoBo; Yang, Yong; Zhang, Dan; Zhang, Tao; Zhao, Li; Sun, XiangMing; Hu, ShouYang; Jian, SiYu; Li, XingLong; Li, XiaoMei; Liang, Hao; Zhang, HuanQiao; Zhao, MingRui; Zhou, Jing; Mao, YaJun; Qiao, Hao; Wang, SiGuang; Yuan, Ying; Wang, Meng; Khan, Amir N.; Raper, Neill; Tang, Jian; Wang, Wei; Dong, JiaNing; Feng, ChangQing; Li, Cheng; Liu, JianBei; Liu, ShuBin; Wang, XiaoLian; Zhu, DanYang; Castel, Juan F.; Cebrián, Susana; Dafni, Theopisti; Garza, Javier G.; Irastorza, Igor G.; Iguaz, Francisco J.; Luzón, Gloria; Mirallas, Hector; Aune, Stephan; Berthoumieux, Eric; Bedfer, Yann; Calvet, Denis; d'Hose, Nicole; Delbart, Alain; Diakaki, Maria; Ferrer-Ribas, Esther; Ferrero, Andrea; Kunne, Fabienne; Neyret, Damien; Papaevangelou, Thomas; Sabatié, Franck; Vanderbroucke, Maxence; Tan, AnDi; Haxton, Wick; Mei, Yuan; Kobdaj, Chinorat; Yan, Yu-Peng

    2017-06-01

    Searching for the neutrinoless double beta decay (NLDBD) is now regarded as the topmost promising technique to explore the nature of neutrinos after the discovery of neutrino masses in oscillation experiments. PandaX-III (particle and astrophysical xenon experiment III) will search for the NLDBD of 136Xe at the China Jin Ping Underground Laboratory (CJPL). In the first phase of the experiment, a high pressure gas Time Projection Chamber (TPC) will contain 200 kg, 90% 136Xe enriched gas operated at 10 bar. Fine pitch micro-pattern gas detector (Microbulk Micromegas) will be used at both ends of the TPC for the charge readout with a cathode in the middle. Charge signals can be used to reconstruct the electron tracks of the NLDBD events and provide good energy and spatial resolution. The detector will be immersed in a large water tank to ensure 5 m of water shielding in all directions. The second phase, a ton-scale experiment, will consist of five TPCs in the same water tank, with improved energy resolution and better control over backgrounds.

  18. Study of the Beta-Decay Properties of Extremely Proton-Rich Nuclei

    CERN Multimedia

    2002-01-01

    The most proton-rich nuclei known to date have isospin projections $ T _{Z} $ ~=~-3/2, -2 and -5/2. \\\\ \\\\ We propose to carry out a study of their superallowed beta decays, a phenomenon that can only be studied in this region of the nuclear chart. The main aim is to determine the ``effective charge'' in nuclei of the axial vector coupling, the quantity $ ( g'_{A} / g _{A} ) ^{2} $ , which in a recent first experiment on a ~~ $ T _{Z} $~~=~-2 nucleus was determined to be 0.49~$\\pm$~0.05. \\\\ \\\\ Because of the problems connected with the production and acceleration of radioactive ions, our proposal aims at selected elements: neon, argon and rubidium (production runs), magnesium (test and production runs) and calcium (test). Data have so far been taken for $^1

  19. Beta-gamma spectroscopy for double beta decays and Lepton number conservation

    International Nuclear Information System (INIS)

    Ejiri, H.; Takahashi, N.; Shibata, T.; Nagai, Y.; Okada, K.; Kamikubota, N.; Watanabe, T.

    1984-01-01

    In this paper neutrino-less double β decays (Oν ββ) of /sup 76/Ge were studied by means of the newly developed ELEGANTS (Electron gamma-ray neutrino spectrometer). It consists of a 171 cc pure Ge detector surrounded bu a big 4π-NaI detector, and active and inactive filters. Measurement of both the electron signal from the Ge detector and γ-ray signals from the 4π-NaI detector made it possible to select the true double decay events from background events due to the other radio-active isotopes and cosmic rays. The ELEGANTS showed the highest sensitivity for detecting the neutrino-less double β decay. The preliminary data obtained so far give a lower limit of the half life T/sub 1/2/≥2.2 10/sup 22/y for the O/sup +/→O/sup +/ Oν ββ decay and T/sub 1/2/ ≥1.5.10/sup 22/y for the O/sup +/→2/sup +/ Oν ββ decay of /sup 76/Ge

  20. The Mechanism of $\\beta$-Delayed Two-Proton Emission

    CERN Multimedia

    2002-01-01

    The nucleus $^{31}$Ar seems to be the most prolific ${\\beta}$-2p precursor known to date and is at the same time the one with the largest production yields at ISOLDE, where the most sensitive experiments can be done. Our purpose with this experiment is to study the ${\\beta}$-2p branches in detail, search for ${\\beta}$-3p events, place them in the decay scheme and obtain information on the decay mechanism for ${\\beta}$-2p via the energy distribution and the angular correlation between the two protons. As a by product we shall also resolve existing inconsistencies in the level scheme.\\\\ \\\\ The nucleus $^{31}$Ar, produced in a cold plasma ion source unit by the impact of a 1 GeV proton beam of 0.5 Hz frequency, had an average yield over one week of 1.5 $^{31}$Ar atoms/s. The beam passed through the central hole of an annular Si detector ($\\Omega$ = 4.3~\\%) and stopped in a thin carbon foil tilted 45$^o$ with respect to the beam direction. A 70~\\% coaxial HPGe-detector ($\\Omega$~=~7.4~\\%) was located opposite to ...

  1. $\\beta$-decay half-life of $^{70}$Kr a bridge nuclide for the rp-process beyond A = 70

    CERN Document Server

    Oinonen, M; Jokinen, A; Baumann, P; Didierjean, François; Huck, A; Knipper, A; Ramdhane, M; Walter, G; Van Duppen, P; Huyse, M; Marguier, G; Novikov, Yu N; Popov, A; Seliverstov, D M; Schatz, H

    2000-01-01

    The $\\beta$-decay half-life of $^{70}$Kr has been measured for the first time at the ISOLDE PSB Facility at CERN. Mass separated $^{70}$Kr ions were produced by 1 GeV proton induced spallation reactions in a Nb foil. The measured half-life is 57(21) ms. This value is consistent with the half-life calculated assuming a pure Fermi decay, but is clearly lower than the value used in a recent rp-process reaction flow calculation. The result shows that the reaction flow via two-proton-capture of $^{68}$Se is 2.5 times faster than previously calculated assuming an astrophysical temperature of 1.5 GK and a density of 10$^{6}$g/cm$^{3}$.

  2. LUCIFER: a scintillating bolometer array for the search of neutrinoless double beta decay

    International Nuclear Information System (INIS)

    Cardani, Laura

    2011-01-01

    In spite of the high precision achieved in the field of neutrino oscillations, there are some fundamental questions that can not be addressed by a study of ths phenomenon. We do not know in fact the absolute mass of neutrino and weather it is a Dirac or a Majorana particle. The LUCIFER experiment, financed by the ERC-AdG, will play an important role in this field. This project aims to push beyond the actual technological limits the possibility of observation of the Neutrinoless Double Beta Decay (0νDBD). The detection of this extremely rare decay would indeed demonstrate that neutrino is a Majorana particle and, at the same time, would allow to set its absolute mass scale. LUCIFER will study the 0νDBD do 82 Se through ZnSe scintillating bolometers. Thanks to the simultaneous red-out of the heat and light produced by an interaction in the crystal, the background rate in the region of interest will be lower than 10 -3 counts/kg/keV/years. In the following, the expected performance of LUCIFER are discussed.

  3. Measuring nuclear reaction cross sections to extract information on neutrinoless double beta decay

    Science.gov (United States)

    Cavallaro, M.; Cappuzzello, F.; Agodi, C.; Acosta, L.; Auerbach, N.; Bellone, J.; Bijker, R.; Bonanno, D.; Bongiovanni, D.; Borello-Lewin, T.; Boztosun, I.; Branchina, V.; Bussa, M. P.; Calabrese, S.; Calabretta, L.; Calanna, A.; Calvo, D.; Carbone, D.; Chávez Lomelí, E. R.; Coban, A.; Colonna, M.; D'Agostino, G.; De Geronimo, G.; Delaunay, F.; Deshmukh, N.; de Faria, P. N.; Ferraresi, C.; Ferreira, J. L.; Finocchiaro, P.; Fisichella, M.; Foti, A.; Gallo, G.; Garcia, U.; Giraudo, G.; Greco, V.; Hacisalihoglu, A.; Kotila, J.; Iazzi, F.; Introzzi, R.; Lanzalone, G.; Lavagno, A.; La Via, F.; Lay, J. A.; Lenske, H.; Linares, R.; Litrico, G.; Longhitano, F.; Lo Presti, D.; Lubian, J.; Medina, N.; Mendes, D. R.; Muoio, A.; Oliveira, J. R. B.; Pakou, A.; Pandola, L.; Petrascu, H.; Pinna, F.; Reito, S.; Rifuggiato, D.; Rodrigues, M. R. D.; Russo, A. D.; Russo, G.; Santagati, G.; Santopinto, E.; Sgouros, O.; Solakci, S. O.; Souliotis, G.; Soukeras, V.; Spatafora, A.; Torresi, D.; Tudisco, S.; Vsevolodovna, R. I. M.; Wheadon, R. J.; Yildirin, A.; Zagatto, V. A. B.

    2018-02-01

    Neutrinoless double beta decay (0vββ) is considered the best potential resource to access the absolute neutrino mass scale. Moreover, if observed, it will signal that neutrinos are their own anti-particles (Majorana particles). Presently, this physics case is one of the most important research “beyond Standard Model” and might guide the way towards a Grand Unified Theory of fundamental interactions. Since the 0vββ decay process involves nuclei, its analysis necessarily implies nuclear structure issues. In the NURE project, supported by a Starting Grant of the European Research Council (ERC), nuclear reactions of double charge-exchange (DCE) are used as a tool to extract information on the 0vββ Nuclear Matrix Elements. In DCE reactions and ββ decay indeed the initial and final nuclear states are the same and the transition operators have similar structure. Thus the measurement of the DCE absolute cross-sections can give crucial information on ββ matrix elements. In a wider view, the NUMEN international collaboration plans a major upgrade of the INFN-LNS facilities in the next years in order to increase the experimental production of nuclei of at least two orders of magnitude, thus making feasible a systematic study of all the cases of interest as candidates for 0vββ.

  4. Commissioning of the IDS Neutron Detector and $\\beta$-decay fast-timing studies at IDS

    CERN Document Server

    Piersa, Monika

    2016-01-01

    The following report describes my scientific activities performed during the Summer Student Programme at ISOLDE. The main part of my project was focused on commissioning the neutron detector dedicated to nuclear decay studies at ISOLDE Decay Station (IDS). I have participated in all the steps needed to make it operational for the IS609 experiment. In the testing phase, we obtained expected detector response and calibrations confirmed its successful commissioning. The detector was mounted in the desired geometry at IDS and used in measurements of the beta-delayed neutron emission of $^8$He. After completing aforementioned part of my project, I became familiar with the fast-timing method. This technique was applied at IDS in the IS610 experiment performed in June 2016 to explore the structure of neutron-rich $^{130-134}$Sn nuclei. Since the main part of my PhD studies will be the analysis of data collected in this experiment, the second part of my project was dedicated to acquiring knowledge about technical de...

  5. Exploring the neutrinoless double beta decay in the inverted neutrino hierarchy with bolometric detectors

    Energy Technology Data Exchange (ETDEWEB)

    Artusa, D.R. [University of South Carolina, Department of Physics and Astronomy, Columbia, SC (United States); INFN-Laboratori Nazionali del Gran Sasso, Assergi, L' Aquila (Italy); Avignone, F.T.; Chott, N.; Creswick, R.J.; Farach, H.A.; Rosenfeld, C.; Wilson, J. [University of South Carolina, Department of Physics and Astronomy, Columbia, SC (United States); Azzolini, O.; Camacho, A.; De Biasi, A.; Keppel, G.; Palmieri, V.; Pira, C.; Rampazzo, V. [INFN-Laboratori Nazionali di Legnaro, Legnaro, Padua (Italy); Balata, M.; Bucci, C.; Canonica, L.; Casali, N.; Di Vacri, M.L.; Goett, J.; Gorla, P.; Nisi, S.; Orlandi, D.; Pattavina, L.; Pirro, S.; Zarra, C. [INFN-Laboratori Nazionali del Gran Sasso, Assergi, L' Aquila (Italy); Banks, T.I. [INFN-Laboratori Nazionali del Gran Sasso, Assergi, L' Aquila (Italy); University of California, Department of Physics, Berkeley, CA (United States); Lawrence Berkeley National Laboratory, Nuclear Science Division, Berkeley, CA (United States); Bari, G.; Deninno, M.M.; Moggi, N. [INFN-Sezione di Bologna, Bologna (Italy); Beeman, J. [Lawrence Berkeley National Laboratory, Materials Science Division, Berkeley, CA (United States); Bellini, F.; Cardani, L.; Cosmelli, C.; Ferroni, F.; Piperno, G. [Sapienza Universita di Roma, Dipartimento di Fisica, Rome (Italy); INFN-Sezione di Roma, Rome (Italy); Bersani, A. [INFN-Sezione di Genova, Genoa (Italy); Biassoni, M.; Brofferio, C.; Capelli, S.; Carrettoni, M.; Chiesa, D.; Clemenza, M.; Faverzani, M.; Ferri, E.; Fiorini, E.; Giachero, A.; Gironi, L.; Gotti, C.; Maiano, C.; Maino, M.; Nucciotti, A.; Pavan, M.; Sala, E.; Sisti, M.; Terranova, F.; Zanotti, L. [Universita di Milano-Bicocca, Dipartimento di Fisica, Milan (Italy); INFN-Sezione di Milano Bicocca, Milan (Italy); Cai, X.Z.; Cao, X.G.; Fang, D.Q.; Li, Y.L.; Ma, Y.G.; Tian, W.D.; Wang, H.W. [Chinese Academy of Sciences, Shanghai Institute of Applied Physics, Shanghai (China); Carbone, L.; Cremonesi, O.; Datskov, V.; Pessina, G.; Previtali, E.; Rusconi, C. [INFN-Sezione di Milano Bicocca, Milan (Italy); Dafinei, I.; Morganti, S.; Orio, F.; Pettinacci, V.; Tomei, C.; Vignati, M. [INFN-Sezione di Roma, Rome (Italy); Dally, A.; Ejzak, L.; Wielgus, L. [University of Wisconsin, Department of Physics, Madison, WI (United States); Di Domizio, S.; Fernandes, G.; Pallavicini, M. [INFN-Sezione di Genova, Genoa (Italy); Universita di Genova, Dipartimento di Fisica, Genoa (Italy); Franceschi, M.A.; Ligi, C.; Napolitano, T. [INFN-Laboratori Nazionali di Frascati, Frascati, Rome (Italy); Freedman, S.J. [University of California, Department of Physics, Berkeley, CA (United States); Lawrence Berkeley National Laboratory, Nuclear Science Division, Berkeley, CA (United States); Fujikawa, B.K.; Han, K.; Mei, Y.; Smith, A.R. [Lawrence Berkeley National Laboratory, Nuclear Science Division, Berkeley, CA (United States); Giuliani, A.; Tenconi, M. [Centre de Spectrometrie Nucleaire et de Spectrometrie de Masse, Orsay (France); Gutierrez, T.D. [California Polytechnic State University, Physics Department, San Luis Obispo, CA (United States); Haller, E.E. [Lawrence Berkeley National Laboratory, Materials Science Division, Berkeley, CA (United States); University of California, Department of Materials Science and Engineering, Berkeley, CA (United States); Heeger, K.M.; Maruyama, R.H. [Yale University, Department of Physics, New Haven, CT (United States); Hennings-Yeomans, R.; O' Donnell, T. [University of California, Department of Physics, Berkeley, CA (United States); Huang, H.Z.; Liu, X.; Trentalange, S.; Winslow, L.A.; Zhu, B.X. [University of California, Department of Physics and Astronomy, Los Angeles, CA (United States); Kadel, R. [Lawrence Berkeley National Laboratory, Physics Division, Berkeley, CA (United States); Kazkaz, K.; Pedretti, M.; Sangiorgio, S.; Scielzo, N.D. [Lawrence Livermore National Laboratory, Livermore, CA (United States); Kolomensky, Yu.G. [University of California, Department of Physics, Berkeley, CA (United States); Lawrence Berkeley National Laboratory, Physics Division, Berkeley, CA (United States); Martinez, M. [Universidad de Zaragoza, Laboratorio de Fisica Nuclear y Astroparticulas, Saragossa (Spain); Nones, C. [CEA/Saclay, Service de Physique des Particules, Gif-sur-Yvette (France); Norman, E.B.; Wang, B.S. [Lawrence Livermore National Laboratory, Livermore, CA (United States); University of California, Department of Nuclear Engineering, Berkeley, CA (United States); Ouellet, J.L. [University of California, Department of Physics, Berkeley, CA (United States); Lawrence Berkeley National Laboratory, Nuclear Science Division, Berkeley, CA (United States); Taffarello, L. [INFN-Sezione di Padova, Padua (Italy); Ventura, G. [Universita di Firenze, Dipartimento di Fisica, Florence (Italy); INFN-Sezione di Firenze, Florence (Italy); Wise, T. [University of Wisconsin, Department of Physics, Madison, WI (United States); Yale University, Department of Physics, New Haven, CT (United States); Woodcraft, A. [University of Edinburgh, SUPA, Institute for Astronomy, Edinburgh (United Kingdom); Zucchelli, S. [INFN-Sezione di Bologna, Bologna (Italy); Universita di Bologna, Dipartimento di Fisica, Bologna (Italy)

    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 bolometric 0νββ 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 (vertical stroke m{sub ee} vertical stroke) of order 10-20 meV, thus completely exploring the so-called inverted neutrino mass hierarchy region. We highlight the main challenges and identify priorities for an R and D program addressing them. (orig.)

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

    Science.gov (United States)

    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.

  7. Atomic effects of beta decay in astrophysics and in elementary particle physics

    International Nuclear Information System (INIS)

    Zonghua, Chen.

    1988-01-01

    The thesis consists mainly of two parts. The first part is a study of the bound-state β decay of 187 Re and its application in Astrophysics. There existed an uncertainty in the ratio ρ b of bound-state to continuum β decay of 187 Re in both theory and experiment. A more definite theoretical result of ρ b ∼ 1% is obtained by using single-configuration and multi-configuration Hartree-Fock-Dirac approximations. The results obtained are close to those obtained by Williams, Fowler, and Koonin by a modified Thomas-Fermi model. The bound-state β decay of 187 Re at high temperatures is also studied. The second part of the thesis is a generalization of the Thomas-Fermi results of various energy contribution to the ground-state energy of a neutral atom. An analytical expression for the ratio of the electron-electron to electron-nuclear interaction is obtained by the corrected Thomas-Fermi result, the ratio obtained gives a better agreement with the Hartree-Fock numerical results

  8. Analysis of super-allowed Fermi beta-decay

    International Nuclear Information System (INIS)

    Wilkinson, D.H.

    1994-11-01

    Analysis of tile Jπ = 0 + → 0 + super-allowed Fermi transitions within isospin triplets is limited in the precision of its outcome not by the accuracy of the experimental input data nor by the confidence with which the radiative corrections can be applied but by knowledge of the nuclear mismatch: the subversion of the isospin symmetry along the multiplets by the charge-dependence of the forces, both Coulomb and specifically nuclear. Theoretical estimates of the mismatch differ considerably from author to author, their direct application results in clear violation of tile hypothesis of conservation of the vector current and clear inconsistency with unitarity of the Cabibbo-Kobayashi-Maskawa matrix. This paper pursues and elaborates the previous suggestion that, in these unsatisfactory circumstances, the best procedure is to look to the experimental data themselves to determine and eliminate the mismatch by appropriate extrapolation to Z=O. This is done: (i) without any prior correction for mismatch; (ii) after correction for the full theoretical mismatch; (iii) after correction for case-to-case fluctuations in the theoretical mismatch. These three procedures are individually statistically satisfactory and mutually consistent in their extrapolation to Z = 0 despite the variety of the theoretical mismatches on which, in varying degrees, they are based. The resultant unitarity test for the CKM matrix is IV ud I 2 + IV us I 2 + IV ub I 2 = 1.0003 ± 0.0014. The associated value for the operational vector coupling constant is: G v * / (hc) 3 = (1.15155±0.00064) x 10 -5 GeV -2 . If unitarity of the CKM matrix is alternatively assumed one may conclude, from a similar analysis, that the mean charge of the fermionic fields between which beta-decay takes place is Q-bar = 0.172±0.060 and that, at the 90% confidence level, b F -3 were b F is the relative effective scalar coupling constant. Neutron decay is also discussed, with the provisional recommendations: G A * /(hc) 3

  9. Reversible Energy Transfer and Fluorescence Decay in Solid Solutions

    Science.gov (United States)

    Shealy, David L.; Hoover, Richard B.; Gabardi, David R.

    1988-07-01

    The article deals with the influence of reversible excitation energy transfer on the fluorescence decay in systems with random distribution of molecules. On the basis of a hopping model, we have obtained an expression for the Laplace transform of the decay function and an expression for the average decay time. The case of dipole-dipole interaction is discussed in detail.

  10. Decay Properties of {sup 147}Nd

    Energy Technology Data Exchange (ETDEWEB)

    Baecklin, A [Inst. of Physics, Univ. of Uppsala (Sweden); Swedish Research Councils' Laboratory, Studsvik, Nykoeping (Sweden); Malmskog, S G [AB Atomenergi, Nykoeping (Sweden)

    1967-02-15

    Electron and gamma transition energies and intensities in the decay of {sup 147}Nd have been studied using a double focussing beta spectrometer and a Ge(Li)-detector. From the deduced multipolarities of the transitions all levels in {sup 147}Pm are found to have positive parity in contrast to the fact that the neighbouring nucleus {sup 149}Pm has been found to have several low lying negative parity states.

  11. Beta decay of 46Cr

    International Nuclear Information System (INIS)

    Onishi, T K; Gelberg, A; Sakurai, H; Yoneda, K; Aoi, N; Imai, N; Baba, H; Brentano, P von; Fukuda, N; Ichikawa, Y; Ishihara, M; Iwasaki, H; Kameda, D; Kishida, T; Lisetskiy, A F; Ong, H J; Osada, M; Otsuka, T; Suzuki, M K; Ue, K; Utsuno, Y; Watanabe, H

    2006-01-01

    The Gamow-Teller transition of 46 Cr to the N = Z odd-odd nucleus 46 V has been observed for the first time. By means of β-γ coincidence measurements, a γ-ray peak at 993 keV corresponding to the decay of the 1 + 1 state in 46 V was observed. The branching ratio of the decay to this state was found to be b GT = 0.25 ± 0.050. The half-life of 46 Cr was measured to be T 1/2 = 240 ± 140 ms. The transition strength was determined to be B(GT) = 0.64 ± 0.20. This result was compared with theoretical calculations

  12. A model for dark energy decay

    Energy Technology Data Exchange (ETDEWEB)

    Abdalla, Elcio, E-mail: eabdalla@usp.br [Instituto de Física, Universidade de São Paulo, CP 66318, 05315-970, São Paulo (Brazil); Graef, L.L., E-mail: leilagraef@usp.br [Instituto de Física, Universidade de São Paulo, CP 66318, 05315-970, São Paulo (Brazil); Wang, Bin, E-mail: wang_b@sjtu.edu.cn [INPAC and Department of Physics, Shanghai Jiao Tong University, 200240 Shanghai (China)

    2013-11-04

    We discuss a model of nonperturbative decay of dark energy. We suggest the possibility that this model can provide a mechanism from the field theory to realize the energy transfer from dark energy into dark matter, which is the requirement to alleviate the coincidence problem. The advantage of the model is the fact that it accommodates a mean life compatible with the age of the universe. We also argue that supersymmetry is a natural set up, though not essential.

  13. Dissipation of Alfven Waves at Fluid Scale through Parametric Decay Instabilities in Low-beta Turbulent Plasma

    Science.gov (United States)

    Fu, X.; Li, H.; Guo, F.; Li, X.; Roytershteyn, V.

    2017-12-01

    The solar wind is a turbulent magnetized plasma extending from the upper atmosphere of the sun to the edge of the heliosphere. It carries charged particles and magnetic fields originated from the Sun, which have great impact on the geomagnetic environment and human activities in space. In such a magnetized plasma, Alfven waves play a crucial role in carrying energy from the surface of the Sun, injecting into the solar wind and establishing power-law spectra through turbulent energy cascades. On the other hand, in compressible plasmas large amplitude Alfven waves are subject to a parametric decay instability (PDI) which converts an Alfven wave to another counter-propagating Alfven wave and an ion acoustic wave (slow mode). The counter-propagating Alfven wave provides an important ingredient for turbulent cascade, and the slow-mode wave provides a channel for solar wind heating in a spatial scale much larger than ion kinetic scales. Growth and saturation of PDI in quiet plasma have been intensively studied using linear theory and nonlinear simulations in the past. Here using 3D hybrid simulations, we show that PDI is still effective in turbulent low-beta plasmas, generating slow modes and causing ion heating. Selected events in WIND data are analyzed to identify slow modes in the solar wind and the role of PDI, and compared with our simulation results. We also investigate the validity of linear Vlasov theory regarding PDI growth and slow mode damping in turbulent plasmas. Since PDI favors low plasma beta, we expect to see more evidence of PDI in the solar wind close to the Sun, especially from the upcoming NASA's Parker Solar Probe mission which will provide unprecedented wave and plasma data as close as 8.5 solar radii from the Sun.

  14. Nuclear decay data files of the Dosimetry Research Group

    International Nuclear Information System (INIS)

    Eckerman, K.F.; Westfall, R.J.; Ryman, J.C.; Cristy, M.

    1993-12-01

    This report documents the nuclear decay data files used by the Dosimetry Research Group at Oak Ridge National Laboratory and the utility DEXRAX which provides access to the files. The files are accessed, by nuclide, to extract information on the intensities and energies of the radiations associated with spontaneous nuclear transformation of the radionuclides. In addition, beta spectral data are available for all beta-emitting nuclides. Two collections of nuclear decay data are discussed. The larger collection contains data for 838 radionuclides, which includes the 825 radionuclides assembled during the preparation of Publications 30 and 38 of the International Commission on Radiological Protection (ICRP) and 13 additional nuclides evaluated in preparing a monograph for the Medical Internal Radiation Dose (MIRD) Committee of the Society of Nuclear Medicine. The second collection is composed of data from the MIRD monograph and contains information for 242 radionuclides. Abridged tabulations of these data have been published by the ICRP in Publication 38 and by the Society of Nuclear Medicine in a monograph entitled ''MIRD: Radionuclide Data and Decay Schemes.'' The beta spectral data reported here have not been published by either organization. Electronic copies of the files and the utility, along with this report, are available from the Radiation Shielding Information Center at Oak Ridge National Laboratory

  15. Beta delayed particle emission in light nuclei

    International Nuclear Information System (INIS)

    Riisager, K.; Gabelmann, H.

    1991-01-01

    A short discussion of theoretical treatments of beta delayed particle emission is followed by a presentation of data on the newly found beta delayed deuteron decay of 6 He. This decay cannot be described properly with existing theories. (author) 8 refs.; 3 figs

  16. Effect of nuclear charge-density distribution, as determined by Hofstadter experiments, on the rate of beta-decay

    International Nuclear Information System (INIS)

    Badibanga, P.

    1975-01-01

    The Fermi functions F(E,Z) have been obtained in this paper for allowed transitions in the case of negatron emission. The potential used in solving the coupled pair of Dirac equations has been derived from the so-called Fermi-type charge-density distribution, where the parameters rho 0 , c and a are those from high-energy electron scattering experiments of Hofstadter et al. The following nuclei were investigated: 20 40 C, 23 51 V, 27 59 Co, 49 115 In, 51 122 Sb, 79 197 Au and 83 209 Bi. The kinetic energy of the emitted electrons was varied from 10 KeV to 10 MeV at intervals of 10 keV. Tables of the Fermi functions F(E,Z) for these nuclei are given in this paper. Also the corrections to the shape of the beta-decay energy spectra eta/sub F-H/(E,Z) were evaluated for the same values of the kinetic energy of the emitted electrons for the nuclei under investigation. Tables of these corrections are presented in this paper. It appears from the results obtained that both F(E,Z) and eta/sub F-H/(E,Z) are uniform functions of energy E; as for the variable Z, the curves obtained are not smooth, but have several kinks or breaks in them. We have found a large peak occurring at Z = 27 (Co), and for eta/sub F-H/(E,Z) In has larger values than Sb

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

    International Nuclear Information System (INIS)

    Goulding, F.S.; Cork, C.P.; Landis, D.A.

    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 22 years (68% confidence) for the half life of the neutrinoless double beta decay (ββ/sub o nu/) of 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 23 years (or more) in a two month/four detector experiment to be carried out soon in an underground facility

  18. Compilation of nuclear decay data used for dose calculation. Revised data for radionuclides listed in ICRP Publication 38

    Energy Technology Data Exchange (ETDEWEB)

    Endo, Akira; Yamaguchi, Yasuhiro [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2001-03-01

    New nuclear decay data used for dose calculation have been compiled for 817 radionuclides that are listed in ICRP Publication 38 (Publ. 38) and for 6 additional isomers. The decay data were prepared using decay data sets from the Evaluated Nuclear Structure Data File (ENSDF), the latest version in August 1997. Basic nuclear properties in the decay data sets that are particularly important for calculating energies and intensities of emissions were examined and updated by referring to NUBASE, the database for nuclear and decay properties of nuclides. The reviewed and updated data were half-life, decay mode and its branching ratio, spin and parity of the ground and isomeric states, excitation energy of isomers, and Q value. In addition, possible revisions of partial and incomplete decay data sets were done for their format and syntax errors, level schemes, normalization records, and so on. After that, the decay data sets were processed by EDISTR in order to compute the energies and intensities of {alpha} particles, {beta} particles, {gamma} rays, internal conversion electrons, X rays, and Auger electrons emitted in nuclear transformation. For spontaneously fissioning nuclides, the average energies and intensities of neutrons, fission fragments, prompt {gamma} rays, delayed {gamma} rays, and {beta} particles were also calculated. The compiled data were prepared in two different types of format: Publ. 38 and NUCDECAY formats. Comparison of the compiled decay data with those in Publ. 38 was also presented. The decay data will be widely used for internal and external dose calculations in radiation protection and will be beneficial to a future revision of ICRP Publ. 38. (author)

  19. Revealing low-energy part of the beta spectra

    International Nuclear Information System (INIS)

    Selvi, S.; Celiktas, C.

    2002-01-01

    An effective method is proposed to separate electronic noise from the beta-particle spectra revealing lower energy part of the spectra. The available methods for reducing the noise problem cut the noise along with the low-energy part of the beta spectra by using a discriminator. Our setup eliminates this undesirable effect by shifting the noise toward the lowest energy scale leaving the low-energy part of spectra undisturbed. We achieved this noise-pulse-separation by treating the noise as a pulse so that we can exploit the application of the pulse-shape analyzer equipment used for pulse shape identification of particles and rejection of defective pulses. To the best of our knowledge this method of the noise separation is a novel approach

  20. Quantum mechanical look at the radioactive-like decay of metastable dark energy

    Energy Technology Data Exchange (ETDEWEB)

    Szydlowski, Marek [Jagiellonian University, Astronomical Observatory, Krakow (Poland); Jagiellonian University, Mark Kac Complex Systems Research Centre, Krakow (Poland); Stachowski, Aleksander [Jagiellonian University, Astronomical Observatory, Krakow (Poland); Urbanowski, Krzysztof [University of Zielona Gora, Institute of Physics, Zielona Gora (Poland)

    2017-12-15

    We derive the Shafieloo, Hazra, Sahni and Starobinsky (SHSS) phenomenological formula for the radioactive-like decay of metastable dark energy directly from the principles of quantum mechanics. To this aim we use the Fock-Krylov theory of quantum unstable states. We obtain deeper insight on the decay process as having three basic phases: the phase of radioactive decay, the next phase of damping oscillations, and finally the phase of power-law decay. We consider the cosmological model with matter and dark energy in the form of decaying metastable dark energy and study its dynamics in the framework of non-conservative cosmology with an interacting term determined by the running cosmological parameter. We study the cosmological implications of metastable dark energy and estimate the characteristic time of ending of the radioactive-like decay epoch to be 2.2 x 10{sup 4} of the present age of the Universe. We also confront the model with astronomical data which show that the model is in good agreement with the observations. Our general conclusion is that we are living in the epoch of the radioactive-like decay of metastable dark energy which is a relict of the quantum age of the Universe. (orig.)

  1. Beta-decay studies near 100Sn

    International Nuclear Information System (INIS)

    Rykaczewski, Krzysztof Piotr; Karny, M.; Batist, L.; Banu, A.; Becker, F.; Blazhev, A.; Burkard, K.; Bruchle, W.; Doring, J.; Faestermann, T.; Gorska, M.; Grawe, H.; Janas, Z.; Jungclaus, A.; Kavatsyuk, M.; Kavatsyuk, O.; Kirchner, R.; La Commara, M.; Mandal, S.; Mazzocchi, C.; Miernik, K.; Mukha, I.; Muralithar, S.; Plettner, C.; Plochocki, A.; Roeckl, E.; Romoli, M.; Schadel, M.; Schmidt, K.; Schwengner, R.; Zylicz, J.

    2005-01-01

    The β-decay of 102 Sn was studied by using high-resolution germanium detectors as well as a Total Absorption Spectrometer (TAS). A decay scheme has been constructed based on the γ-γ coincidence data. The total experimental Gamow-Teller strength B GT exp of 102 Sn was deduced from the TAS data to be 4.2(9). A search for β-delayed γ-rays of 100 Sn decay remained unsuccessful. However, a Gamow-Teller hindrance factor h = 2.2(3), and a cross-section of about 3nb for the production of 100 Sn in fusion-evaporation reaction between 58 Ni beam and 50 Cr target have been estimated from the data on heavier tin isotopes. The estimated hindrance factor is similar to the values derived for lower shell nuclei

  2. Search for neutrinoless double beta decay of Ge-76 with the GERmanium Detector Array '' GERDA ''

    International Nuclear Information System (INIS)

    Brugnera, R.

    2009-01-01

    The study of neutrinoless double beta decay (DBD) is the most powerful approach to the fundamental question if the neutrino is a Majorana particle, i.e. its own anti-particle. The observation of neutrinoless DBD would not only establish the Majorana nature of the neutrino but also represent a determination of its effective mass if the nuclear matrix element is given. So far, the most sensitive results have been obtained with Ge-76, and the group of Klapdor-Kleingrothaus has made a claim of discovery. Future experiments have to reduce radioactive backgrounds to increase the sensitivity. '' GERDA '' is a new double beta-decay experiment which is currently under construction in the INFN Gran Sasso National Laboratory, Italy. It is implementing a new shielding concept by operating bare Ge diodes - enriched in Ge-76 - in high purity liquid argon supplemented by a water shield. The aim of '' GERDA '' is to verify or refute the recent claim of discovery, and, in a second phase, to achieve a two orders of magnitude lower background index than recent experiments, increasing the sensitive mass and reaching exposure of 100 kg yr. It be will discuss design, physics reach, and status of construction of '' GERDA '', and present results from various R efforts including long term stability of bare Ge diodes in cryogenic liquids, material screening, cryostat performance, detector segmentation, cryogenic precision electronics, safety aspects, and Monte Carlo simulations. (author)

  3. Study of neutron-rich $^{51−53}$ Ca isotopes via $\\beta$-decay

    CERN Multimedia

    The high Q$_\\beta$ values in certain neutron-rich regions of the chart of nuclides opens up the possibility to study states in the daughter nuclei which lie at high excitation energy, above the neutron separation threshold. We propose to perform spectroscopy of the $\\beta$-delayed neutron emission of the $^{51-53}$K isotopes to study the population of single-particle or particle-hole states both below and above the neutron separation threshold. The VANDLE neutron detector will be used in combination with the IDS tape station setup and Ge detectors.

  4. $\\sin(2\\beta)$ with $B^0 \\rightarrow\\!J/\\!\\psi K_\\text{S}$ at the LHCb experiment

    CERN Multimedia

    Niet, Ramon

    2015-01-01

    The poster presents the recent measurement of $\\sin(2\\beta)$ using $B^0$ decays to the $J/\\!\\psi K_\\text{S}$ final state. The measurement is based on a dataset corresponding to an integrated luminosity of 3.0$\\,\\text{fb}^{-1}$ collected with the LHCb experiment in proton-proton collisions at center-of-mass energies of 7 and 8 TeV. To control penguin pollutions in the determination of $\\sin(2\\beta)$, $B_s^0$ decays to the same final state can be analysed. The results of the corresponding analysis are presented as well.

  5. Beta-delayed particle decay of 17Ne

    International Nuclear Information System (INIS)

    Morton, A.C.; Chow, J.C.; King, J.D.; Boyd, R.N.; Bateman, N.P.T.; Buchmann, L.; D'Auria, J.M.; Davinson, T.; Dombsky, M.; Galster, W.; Gete, E.; Giesen, U.; Iliadis, C.; Jackson, K.P.; Powell, J.; Roy, G.; Shotter, A.

    2002-01-01

    The β-delayed particle decay of 17 Ne has been studied via proton-γ coincidences, time-of-flight measurements and the ''ratio-cut technique'', allowing cleanly-separated proton and α-particle spectra to be obtained. A complete set of proton and α branching ratios for the decay of 14 excited states in 17 F to the ground and excited states of 16 O and 13 N has been determined and branching ratios for the β decay of 17 Ne to these states have been deduced. From the branching ratios, f A t values and reduced Gamow-Teller matrix elements were calculated; no indication of isospin mixing in the isobaric analog state in 17 F was observed. From the measurement of proton-γ angular correlations, combined with the selection rules for an allowed β decay, we obtain J π =((1)/(2)) - for states at 8.436 and 9.450 MeV and ((3)/(2)) - for the state at 10.030 MeV in 17 F. Probabilities for the β-delayed pα decay to 12 C through the tails of the subthreshold 7.117 and 6.917 MeV states in 16 O have been calculated and the feasibility of using such decays to provide information about the rates for the E1 and E2 components of the 12 C(α,γ) 16 O reaction is discussed

  6. FPDCYS and FPSPEC: computer programs for calculating fission-product beta and gamma multigroup spectra from ENDF/B-IV data

    International Nuclear Information System (INIS)

    Stamatelatos, M.G.; England, T.R.

    1977-05-01

    FPDCYS and FPSPEC are two FORTRAN computer programs used at the Los Alamos Scientific Laboratory (LASL), in conjunction with the CINDER-10 program, for calculating cumulative fission-product beta and/or gamma multigroup spectra in arbitrary energy structures, and for arbitrary neutron irradiation periods and cooling times. FPDCYS processes ENDF/B-IV fission-product decay energy data to generate multigroup beta and gamma spectra from individual ENDF/B-IV fission-product nuclides. FPSPEC further uses these spectra and the corresponding nuclide activities calculated by the CINDER-10 code to produce cumulative beta and gamma spectra in the same energy grids in which FPDCYS generates individual isotope decay spectra. The code system consisting of CINDER-10, FPDCYS, and FPSPEC has been used for comparisons with experimental spectra and continues to be used at LASL for generating spectra in special user-oriented group structures. 3 figures

  7. Energy response of detectors to alpha/beta particles and compatibility of the equivalent factors

    International Nuclear Information System (INIS)

    Lin Bingxing; Li Guangxian; Lin Lixiong

    2011-01-01

    By measuring detect efficiency and equivalent factors of alpha/beta radiation with different energies on three types of detectors, this paper compares compatibility of their equivalent factors and discusses applicability of detectors to measuring total alpha/beta radiation. The result shows the relationship between efficiency of alpha/beta radiation and their energies on 3 types of detectors, such as scintillation and proportional and semiconductor counters, are overall identical. Alpha count efficiency display exponential relation with alpha-particle energy. While beta count efficiency display logarithm relation with beta-particle energy, but the curves appears deflection at low energy. Comparison test of energy response also shows that alpha and beta equivalent factors of scintillation and proportional counters have a good compatibility, and alpha equivalent factors of the semiconductor counters are in good agreement with those of the above two types of counters, but beta equivalent factors have obvious difference, or equivalent factors of low energy beta-particle are lower than those of other detectors. So, the semiconductor counter can not be used for measuring total radioactivity or for the measurements for the purpose of food safety. (authors)

  8. High energy beta rays and vectors of Bilharzia and Fasciola

    International Nuclear Information System (INIS)

    Fletcher, J.J.; Akpa, T.C.; Dim, L.A.; Ogunsusi, R.

    1988-01-01

    Preliminary investigations of the effects of high energy beta rays on Lymnea natalensis, the snail vector of Schistosoma haematobium have been conducted. Results show that in both stream and tap water, about 70% of the snails die when irradiated for up to 18 hours using a 15m Ci Sr-90 beta source. The rest of the snails die without further irradiation in 24 hours. It may then be possible to control the vectors of Bilharzia and Fasciola by using both the direct and indirect effects of high energy betas. (author)

  9. High energy beta rays and vectors of Bilharzia and Fasciola

    Energy Technology Data Exchange (ETDEWEB)

    Fletcher, J.J.; Akpa, T.C.; Dim, L.A.; Ogunsusi, R.

    1988-01-01

    Preliminary investigations of the effects of high energy beta rays on Lymnea natalensis, the snail vector of Schistosoma haematobium have been conducted. Results show that in both stream and tap water, about 70% of the snails die when irradiated for up to 18 hours using a 15m Ci Sr-90 beta source. The rest of the snails die without further irradiation in 24 hours. It may then be possible to control the vectors of Bilharzia and Fasciola by using both the direct and indirect effects of high energy betas.

  10. Beta decay of twelve light neutron-rich isotopes from 17C to 40S

    International Nuclear Information System (INIS)

    Dufour, J.P.; Del Moral, R.; Fleury, A.; Hubert, F.; Jean, D.; Pravikoff, M.S.; Geissel, H.; Schmidt, K.H.

    1986-07-01

    The results reported here have been obtained with an 40 Argon beam on a Be target. The separated nuclei were implanted in a catcher foil placed in between a thin scintillator detecting the betas and a high volume Ge detector; only gammas in coincidence with betas were recorded. Results for the gamma energies and the half-lives of the observed isotopes are given

  11. Shape effects along the Z=82 line: study of the $\\beta$- decay of $^{188,190,192}$Pb using total absorption spectroscopy

    CERN Multimedia

    Caballero ontanaya, L; Garcia borge, M J; Malbrunot, S

    2002-01-01

    This proposal is aimed at the study of the $\\beta$- decay of the neutron-deficient $^{188,190,192}$Pb nuclei. The main motivation of the proposed experiment is to determine the Gamow-Teller strength distribution in the daughter nuclei using the Total Absorption Spectrometer "Lucrecia". Recent theoretical results show that from this measurement the shapes of the ground states of the decaying Pb nuclei can be inferred. This study offers an independent way to study the phenomenon of shape co-existence in a region of particular interest.

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

    International Nuclear Information System (INIS)

    Park, HyangKyu

    2015-01-01

    The AMoRE (Advanced Mo based Rare process Experiment) collaboration is going to use calcium molybdate crystals to search for neutrinoless double beta decay of 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

  13. An attempt for revision of JNDC FP decay data file

    International Nuclear Information System (INIS)

    Katakura, Jun-ichi; Matsumoto, Zyun-itiro; Akiyama, Masatsugu; Yoshida, Tadashi; Nakasima, Ryozo.

    1984-06-01

    Some improvement of JNDC FP Decay Data File is tried by reexamining the decay scheme for several nuclides, since slight discrepancies are seen in detailed comparison of decay powers. As a results, it is found that the average beta- and gamma-energies should be modified for 88 Rb and 143 La among the nuclides reexamined in the present study. The JNDC file modified in 88 Rb and 143 La gives better agreement in most cases with experiments than the original JNDC file for cooling times longer than a few thousands seconds. However, the discrepancy for cooling times from a few hundreds to about 1500 seconds still remains. (author)

  14. Constraints on both the quadratic and quartic symmetry energy coefficients by 2β --decay energies

    Science.gov (United States)

    Wan, Niu; Xu, Chang; Ren, Zhongzhou; Liu, Jie

    2018-05-01

    In this Rapid Communication, the 2 β- -decay energies Q (2 β-) given in the atomic mass evaluation are used to extract not only the quadratic volume symmetry energy coefficient csymv, but also the quartic one csym,4 v. Based on the modified Bethe-Weizsäcker nuclear mass formula of the liquid-drop model, the decay energy Q (2 β-) is found to be closely related to both the quadratic and quartic symmetry energy coefficients csymv and csym,4 v. There are totally 449 data of decay energies Q (2 β-) used in the present analysis where the candidate nuclei are carefully chosen by fulfilling the following criteria: (1) large neutron-proton number difference N -Z , (2) large isospin asymmetry I , and (3) limited shell effect. The values of csymv and csym,4 v are extracted to be 29.345 and 3.634 MeV, respectively. Moreover, the quadratic surface-volume symmetry energy coefficient ratio is determined to be κ =csyms/csymv=1.356 .

  15. Development of segmented germanium detectors for neutrinoless double beta decay experiments

    International Nuclear Information System (INIS)

    Liu, Jing

    2009-01-01

    The results from neutrino oscillation experiments indicate that at least two neutrinos have mass. However, the value of the masses and whether neutrinos and anti-neutrinos are identical, i.e., Majorana particles, remain unknown. Neutrinoless double beta decay experiments can help to improve our understanding in both cases and are the only method currently possible to tackle the second question. The GERmanium Detector Array (GERDA) experiment, which will search for the neutrinoless double beta decay of 76 Ge, is currently under construction in Hall A of the INFN Gran Sasso National Laboratory (LNGS), Italy. In order to achieve an extremely low background level, segmented germanium detectors are considered to be operated directly in liquid argon which serves simultaneously as cooling and shielding medium. Several test cryostats were built at the Max-Planck-Institut fuer Physik in Muenchen to operate segmented germanium detectors both in vacuum and submerged in cryogenic liquid. The performance and the background discrimination power of segmented germanium detectors were studied in detail. It was proven for the first time that segmented germanium detectors can be operated stably over long periods submerged in a cryogenic liquid. It was confirmed that the segmentation scheme employed does well in the identification of photon induced background and demonstrated for the first time that also neutron interactions can be identified. The C++ Monte Carlo framework, MaGe (Majorana-GERDA), is a joint development of the Majorana and GERDA collaborations. It is based on GEANT4, but tailored especially to simulate the response of ultra-low background detectors to ionizing radiation. The predictions of the simulation were veri ed to be accurate for a wide range of conditions. Some shortcomings were found and corrected. Pulse shape analysis is complementary to segmentation in identifying background events. Its efficiency can only be correctly determined using reliable pulse shape

  16. Development of segmented germanium detectors for neutrinoless double beta decay experiments

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Jing

    2009-06-09

    The results from neutrino oscillation experiments indicate that at least two neutrinos have mass. However, the value of the masses and whether neutrinos and anti-neutrinos are identical, i.e., Majorana particles, remain unknown. Neutrinoless double beta decay experiments can help to improve our understanding in both cases and are the only method currently possible to tackle the second question. The GERmanium Detector Array (GERDA) experiment, which will search for the neutrinoless double beta decay of {sup 76}Ge, is currently under construction in Hall A of the INFN Gran Sasso National Laboratory (LNGS), Italy. In order to achieve an extremely low background level, segmented germanium detectors are considered to be operated directly in liquid argon which serves simultaneously as cooling and shielding medium. Several test cryostats were built at the Max-Planck-Institut fuer Physik in Muenchen to operate segmented germanium detectors both in vacuum and submerged in cryogenic liquid. The performance and the background discrimination power of segmented germanium detectors were studied in detail. It was proven for the first time that segmented germanium detectors can be operated stably over long periods submerged in a cryogenic liquid. It was confirmed that the segmentation scheme employed does well in the identification of photon induced background and demonstrated for the first time that also neutron interactions can be identified. The C++ Monte Carlo framework, MaGe (Majorana-GERDA), is a joint development of the Majorana and GERDA collaborations. It is based on GEANT4, but tailored especially to simulate the response of ultra-low background detectors to ionizing radiation. The predictions of the simulation were veri ed to be accurate for a wide range of conditions. Some shortcomings were found and corrected. Pulse shape analysis is complementary to segmentation in identifying background events. Its efficiency can only be correctly determined using reliable pulse

  17. Double-beta decay: Physics beyond the standard model now and in the future (GENIUS)

    International Nuclear Information System (INIS)

    Klapdor-Kleingrothaus, H.V.

    1998-01-01

    Nuclear double beta decay has an extraordinarily broad potential in searches for physics beyond the Standard Model, probing already now the TeV scale, at which new physics is expected to manifest itself. These possibilities are reviewed here. First, the result of present-generation experiments are discussed. The most sensitive one of these, the Heidelberg-Moscow experiment at the Gran Sasso underground laboratory, probes the electron mass now in the sub-eV region and will reach a limit of some 0.1 eV in a few years. On the basis of a large amount of theoretical work done by the Heidelberg Double Beta Group in the last two years, results are obtained also for SUSY models (R-parity breaking and neutrino mass), for leptoquarks (leptoquark-Higgs boson coupling), for compositeness, for right-handed W-boson mass, and for some other problems. These results are comfortably competitive with corresponding results from high-energy accelerators like Tevatron, HERA, etc. Future prospects for ββ research are discussed. A new Heidelberg experimental proposal (GENIUS) is presented, which would make it possible to increase the sensitivity for the Majorana neutrino masses from the present level of at best 0.1 eV down to 0.01 or even 0.001 eV. Its physical potential would be a breakthrough into the multi-TeV range for many models beyond standard. Its sensitivity for neutrino-oscillation parameters would be higher than that of all present terrestrial neutrino-oscillation experiments and that of those planned for the future. It would further, even at a first step, cover almost the full MSSM parameter space for prediction of neutralinos as cold dark matter, making the experimental competitive with LHC in searches for supersymmetry

  18. Calculation of low-energy reactor neutrino spectra reactor for reactor neutrino experiments

    Energy Technology Data Exchange (ETDEWEB)

    Riyana, Eka Sapta; Suda, Shoya; Ishibashi, Kenji; Matsuura, Hideaki [Dept. of Applied Quantum Physics and Nuclear Engineering, Kyushu University, Kyushu (Japan); Katakura, Junichi [Dept. of Nuclear System Safety Engineering, Nagaoka University of Technology, Nagaoka (Japan)

    2016-06-15

    Nuclear reactors produce a great number of antielectron neutrinos mainly from beta-decay chains of fission products. Such neutrinos have energies mostly in MeV range. We are interested in neutrinos in a region of keV, since they may take part in special weak interactions. We calculate reactor antineutrino spectra especially in the low energy region. In this work we present neutrino spectrum from a typical pressurized water reactor (PWR) reactor core. To calculate neutrino spectra, we need information about all generated nuclides that emit neutrinos. They are mainly fission fragments, reaction products and trans-uranium nuclides that undergo negative beta decay. Information in relation to trans-uranium nuclide compositions and its evolution in time (burn-up process) were provided by a reactor code MVP-BURN. We used typical PWR parameter input for MVP-BURN code and assumed the reactor to be operated continuously for 1 year (12 months) in a steady thermal power (3.4 GWth). The PWR has three fuel compositions of 2.0, 3.5 and 4.1 wt% {sup 235}U contents. For preliminary calculation we adopted a standard burn-up chain model provided by MVP-BURN. The chain model treated 21 heavy nuclides and 50 fission products. The MVB-BURN code utilized JENDL 3.3 as nuclear data library. We confirm that the antielectron neutrino flux in the low energy region increases with burn-up of nuclear fuel. The antielectron-neutrino spectrum in low energy region is influenced by beta emitter nuclides with low Q value in beta decay (e.g. {sup 241}Pu) which is influenced by burp-up level: Low energy antielectron-neutrino spectra or emission rates increase when beta emitters with low Q value in beta decay accumulate. Our result shows the flux of low energy reactor neutrinos increases with burn-up of nuclear fuel.

  19. Measurement of the $\\beta$-asymmetry parameter in $^{35}$Ar decay with a laser polarized beam

    CERN Multimedia

    With this proposal we request beam time for the first two phases of a project that aims at measuring the $\\beta$-asymmetry parameter of the mirror $\\beta$-decay branch in $^{35}$Ar using an optically polarized Ar atom beam. The final goal of the experiment is to measure this parameter to a precision of 0.5%. This will allow the most precise determination of the V$_{ud}$ quark mixing matrix element from all the mirror transitions with an absolute uncertainty of 0.0007. The proposal will be presented in phases and we ask here 11 shifts (7 on-line + 4 off-line) for phase 1 and 15 shifts (6 on-line and 9 off-line) for phase 2. Phase 1 aims at establishing the optimal laser polarization scheme as well as the best implantation host for maintaining the polarization. Phase 2 aims at enhancing the beam polarization by removing the unpolarized part of the beam using re-ionization.

  20. Decay profiles of {beta} and {gamma} for a radionuclide inventory in equilibrium cycle of a BWR type reactor; Perfiles de decaimiento de radiacion {beta} y {gamma} para un inventario de radionuclidos en ciclo de equilibrio de un reactor tipo BWR

    Energy Technology Data Exchange (ETDEWEB)

    Salaices, M.; Sandoval, S.; Ovando, R. [Instituto de Investigaciones Electricas. Gerencia de Energia Nuclear, Av. Reforma 113 Col. Palmira. 62490 Cuernavaca, Morelos (Mexico)]. e-mail: sal@iie.org.mx

    2007-07-01

    Presently work the {beta} and {gamma} radiation decay profiles for a radionuclides inventory in equilibrium cycle of a BWR type reactor is presented. The profiles are presented in terms of decay in the activity of the total inventory as well as of the chemical groups that conform the inventory. In the obtaining of the radionuclides inventory in equilibrium cycle the ORIGEN2 code, version 1 was used, which simulates fuel burnup cycles and it calculates the evolution of the isotopic composition as a result of the burnt one, irradiation and decay of the nuclear fuel. It can be observed starting from the results that the decrease in the activity for the initial inventory and the different chemical groups that conform it is approximately proportional to the base 10 logarithm of the time for the first 24 hours of having concluded the burnt one. It can also be observed that the chemical groups that contribute in more proportion to the total activity of the inventory are the lanthanides-actinides and the transition metals, with 39% and 28%, respectively. The groups of alkaline earth metals, halogens, metalloids, noble gases and alkaline metals, contribute with percentages that go from the 8 to 5%. The groups that less they contribute to the total activity of the inventory they are the non metals and semi-metals with smaller proportions that 1%. The chemical groups that more contribute to the energy of {beta} and {gamma} radiation its are the transition metals and the lanthanides-actinides with a change in the order of importance at the end of the 24 hours period. The case of the halogens is of relevance for the case of the {gamma} radiation energy due that occupying the very near third site to the dimensions of the two previous groups. Additionally, the decay in the activity for the total inventory and the groups that conform it can be simulated by means of order 6 polynomials or smaller than describe its behavior appropriately. The results presented in this work, coupled