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51. Status of the Majorana Demonstrator experiment

Author

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

Subjects
Nuclear physics, Physics, MAJORANA, Particle physics, Double beta decay, Neutrino
Abstract

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

Published
2014
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52. (t,3He) Reaction; New tool for studying spin-isospin excitations in neutron rich nuclei

Author

K. Ishibashi, T. Inomata, Ryuta Hazama, M.H. Tanaka, K. Pham, Yoshitaka Fujita, Sam M. Austin, J. W. Jänecke, Shintaro Nakayama, G.P.A. Berg, I. Daito, Mamoru Fujiwara, M. Yosoi, H. Fujimura, B. Davids, M. Steiner, Hiroyuki Toyokawa, B. M. Sherrill, D.A. Roberts, Hidetoshi Akimune, J. A. Brown, Atsushi Tamii, and D. Bazin

Subjects
Physics, Nuclear and High Energy Physics, Nuclear Theory, Resolution (electron density), Spectral line, Nuclear physics, Yield (chemistry), Isospin, Physics::Accelerator Physics, Neutron, Atomic physics, Nuclear Experiment, Dispersion (chemistry), Spin (physics), Instrumentation, Beam (structure)
Abstract

Initial experiments were carried out to study spin-isospin transitions in nuclei using (t,3He) measurements. A triton beam was produced from the breakup reaction (4He,t-p) on a 9.25 g/cm2 Be production target using a 4He beam of 620 MeV. With a beam of 70 enA a yield of 381 MeV tritons with 4.5 × 106 particles/s was achieved. The first half of the A1200 beam transport system at NSCL was used to analyze the triton beam. The energy spread at the target position was estimated to be about 23 MeV. The second half of the A1200 was used to analyze the energy of 3He particles from the (t,3He) reaction. The dispersion matching method was applied to obtain good energy resolution despite the significant energy spread of the incident tritons. The achromatic properties of the A1200 system made it possible to obtain high-resolution (t,3He) spectra at θ = 0° with a resolution of ΔEE = 0.002 (ΔE = 780 keV).

Published
1997
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53. CANDLES project for double beta decay of 48Ca

Author

K. Ichihara, Ryuta Hazama, S. Yoshida, Saori Umehara, K. Mukaida, Izumi Ogawa, K. Matsuoka, Tadafumi Kishimoto, Y. Tatewaki, and D. Yokoyama

Subjects
Physics, Nuclear physics, Nuclear and High Energy Physics, Particle physics, Physics::Instrumentation and Detectors, Astrophysics::High Energy Astrophysical Phenomena, Double beta decay, Detector, High Energy Physics::Experiment, Beta (velocity), Detection theory, Atomic and Molecular Physics, and Optics
Abstract

CANDLES is the project to search for neutrino-less double beta (0 νββ ) decay of 48 Ca. The expected performance of the detector for the signal detection and the background rejection are presented. The current status of development for the detector system is also described.

Published
2005
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54. MOON (Mo Observatory Of Neutrinos) for double beta decay

Author

A. Rjazantsev, V. Voronov, P. J. Doe, D.I. Will, Hironobu Nakamura, Alexander I. Titov, K. Matsuoka, V. Kutsalo, K. Ichihara, Y. Shichijo, Masaharu Nomachi, P. Kavitov, Tatsushi Shima, Joseph A. Formaggio, V. Vatulin, S. R. Elliott, K. Kuroda, A. N. Sissakian, J. F. Wilkerson, Vladimir Kekelidze, Ken-Ichi Fushimi, R. G. H. Robertson, Hideshi Ishii, Jonathan Engel, O.E. Vilches, T. Ogama, Grigori Shirkov, Y. Shimada, V. M. Gehman, Yorihito Sugaya, A. Gorin, H. Ejiri, Takahisa Itahashi, M. B. Greenfield, Y. Ikegami, Ryuta Hazama, Keith Rielage, M. Finger, A. Para, I. Manouilov, and S. Yoshida

Subjects
Physics, Nuclear and High Energy Physics, Solar neutrino, Detector, Resolution (electron density), Astrophysics, Atomic and Molecular Physics, and Optics, Coincidence, Observatory, Beta (plasma physics), Double beta decay, Physics::Space Physics, High Energy Physics::Experiment, Astrophysics::Earth and Planetary Astrophysics, Neutrino
Abstract

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

Published
2005
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55. Combined analysis of all three phases of solar neutrino data from the Sudbury Neutrino Observatory

Author

M. Kos, Peter Watson, L. L. Kormos, Jocelyn Monroe, B. C. Robertson, G. T. Ewan, K. Boudjemline, M. H. Schwendener, M. Huang, E. Guillian, B. Aharmim, T. Kutter, B. G. Nickel, P. J. Doe, F. Zhang, J. R. Leslie, A. W. P. Poon, M. Bergevin, N. Gagnon, J. Law, G. D. Orebi Gann, P.-L. Drouin, Yuen-Dat Chan, K. Graham, F. A. Duncan, S. M. Oser, Hal Evans, N. McCauley, M. L. Miller, B. Beltran, G. Prior, S. D. Reitzner, S. N. Ahmed, R. D. Martin, H. Deng, Christopher C. M. Kyba, Steven Elliott, R. G. H. Robertson, R. J. Ford, C. Kraus, T. Sonley, R. Van Berg, Kai Zuber, P. Jagam, Rachel Rosten, M. Dunford, J. Wendland, S. J. M. Peeters, Olivier Simard, Keith Rielage, A. L. Hallin, A. Krüger, J. F. Wilkerson, G. Doucas, R. W. Ollerhead, A. Hime, N. West, A. J. Noble, C. B. Krauss, W. J. Heintzelman, F. Fleurot, A. E. Anthony, H. Wan Chan Tseung, M. L. Chen, S. Habib, Bei Cai, H. M. O'Keeffe, K. T. Lesko, D. L. Wark, D. Chauhan, Joseph A. Formaggio, Minfang Yeh, J. M. Wouters, Ryuta Hazama, B. T. Cleveland, S. Majerus, J. C. Loach, N. A. Jelley, H. B. Mak, J. Maneira, M. Jerkins, N. Tolich, J. J. Simpson, G. Tešić, J. Tm. Goon, A. B. McDonald, S. McGee, R. L. Hahn, S. D. Biller, R. A. Ott, P. J. Harvey, C. J. Virtue, E. D. Hallman, N. Barros, B.A. VanDevender, C. Howard, J. Farine, J. R. Wilson, J. Heise, T. Tsui, E. W. Beier, M. DiMarco, B. Jamieson, S. Seibert, R. MacLellan, N. S. Oblath, Mark Guy Boulay, R. L. Helmer, J. R. Klein, P. Skensved, X. Dai, J. A. Detwiler, R. Lange, J. A. Secrest, I. T. Lawson, L. C. Stonehill, G. A. Cox, Benjamin Monreal, E. D. Earle, K. J. Keeter, A. Wright, H. Fergani, and Alain Bellerive

Subjects
Nuclear and High Energy Physics, Particle physics, Solar neutrino, FOS: Physical sciences, Cosmic ray, 7. Clean energy, 01 natural sciences, Particle identification, High Energy Physics - Experiment, Nuclear physics, High Energy Physics - Experiment (hep-ex), High Energy Physics - Phenomenology (hep-ph), 0103 physical sciences, Nuclear Experiment (nucl-ex), 010306 general physics, Neutrino oscillation, Nuclear Experiment, Charged current, Solar and Stellar Astrophysics (astro-ph.SR), Physics, Sudbury Neutrino Observatory, Neutral current, 010308 nuclear & particles physics, QC0793, High Energy Physics - Phenomenology, Astrophysics - Solar and Stellar Astrophysics, Neutrino
Abstract

We report results from a combined analysis of solar neutrino data from all phases of the Sudbury Neutrino Observatory. By exploiting particle identification information obtained from the proportional counters installed during the third phase, this analysis improved background rejection in that phase of the experiment. The combined analysis resulted in a total flux of active neutrino flavors from 8B decays in the Sun of (5.25 \pm 0.16(stat.)+0.11-0.13(syst.))\times10^6 cm^{-2}s^{-1}. A two-flavor neutrino oscillation analysis yielded \Deltam^2_{21} = (5.6^{+1.9}_{-1.4})\times10^{-5} eV^2 and tan^2{\theta}_{12}= 0.427^{+0.033}_{-0.029}. A three-flavor neutrino oscillation analysis combining this result with results of all other solar neutrino experiments and the KamLAND experiment yielded \Deltam^2_{21} = (7.41^{+0.21}_{-0.19})\times10^{-5} eV^2, tan^2{\theta}_{12} = 0.446^{+0.030}_{-0.029}, and sin^2{\theta}_{13} = (2.5^{+1.8}_{-1.5})\times10^{-2}. This implied an upper bound of sin^2{\theta}_{13} < 0.053 at the 95% confidence level (C.L.).

Published
2013

56. Limits on neutrino-less double beta decay of 100Mo

Author

Kyo Kume, Ken-Ichi Fushimi, Junki Tanaka, Tatsushi Shima, Keitaro Nagata, Kei Okada, Tadafumi Kishimoto, H. Ohsumi, Hiroyasu Ejiri, K. Hayashi, Nobuyuki Kudomi, and Ryuta Hazama

Subjects
Physics, Nuclear physics, Nuclear and High Energy Physics, Double beta decay, Beta (velocity), Neutrino, Lower limit, Majoron
Abstract

Exclusive measurements of neutrino-less double beta decays (0νββ) of 100Mo were made by means of ELEGANT V. Most stringent lower limits on the half-lives for the ground-state transition were obtained for the 0νββ processes as T 1 2 0ν (m ν ) > 5.2 × 10 22 y , T 1 2 0ν (λ) > 3.9 × 10 22 y and T 1 2 0ν (η) > 5.1 × 10 22 y , for the mass term 〈mν〉, for the right-handed current terms of 〈λ〉 and 〈η〉, respectively, and as T 1 2 0νB > 5.4 × 10 21 y for the process (0νββB) followed by a Majoron (B). These limits lead to the upper limits of 〈mν〉

Published
1996
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57. Measurement of theνeand total8B solar neutrino fluxes with the Sudbury Neutrino Observatory phase-III data set

Author

M. DiMarco, R. J. Ford, R. W. Ollerhead, R. MacLellan, Mark Guy Boulay, P. Jagam, M. H. Schwendener, A. Krüger, B. C. Robertson, J. Tm. Goon, N. Gagnon, G. Doucas, F. Zhang, J. R. Wilson, J. B. Wilhelmy, S. Habib, R. L. Helmer, S. R. Seibert, J. Law, T. Kutter, J. Heise, N. West, P.-L. Drouin, P. Skensved, Hal Evans, F. Fleurot, G. D. Orebi Gann, J. F. Amsbaugh, Ryuta Hazama, H. Wan Chan Tseung, M. L. Miller, A. E. Anthony, J. V. Germani, E. D. Hallman, W. J. Heintzelman, H. Deng, K. M. Heeger, E. Guillian, C. Kraus, S. D. Biller, J. R. Leslie, S. Majerus, Yuen-Dat Chan, K. Boudjemline, K. Graham, M. W.E. Smith, L. L. Kormos, Alain Bellerive, Bernie G. Nickel, J. Wendland, S. M. Oser, S. R. Elliott, G. T. Ewan, Andrew Hime, Joshua R. Klein, A. W. Myers, P. J. Harvey, Juan-Manuel Anaya, J. Banar, K. T. Lesko, Monica Dunford, J. Maneira, M. A. Howe, M. Huang, Reyco Henning, P. M. Thornewell, N. Barros, T. J. Sonley, A. W. P. Poon, S. D. Reitzner, S. N. Ahmed, R. D. Martin, J. J. Simpson, Malcolm M. Fowler, Kai Zuber, T. J. Bowles, C. D. Tunnell, P. J. Doe, G. Tešić, J. A. Formaggio, M. Bergevin, C. A. Duba, N. McCauley, A. Goldschmidt, Bei Cai, Minfang Yeh, E. Rollin, R. G. H. Robertson, R. A. Ott, T.H. Burritt, D. Chauhan, R. Van Berg, H. B. Mak, C. J. Virtue, B. Jamieson, J. F. Wilkerson, T. D. Van Wechel, K. J. Keeter, A. Wright, J. C. Loach, C. Currat, N. A. Jelley, S. J. M. Peeters, T. D. Steiger, M. L. Chen, T. V. Bullard, M. Kos, A. A. Hamian, O. Simard, X. Dai, J. A. Detwiler, R. Lange, G. Prior, C. Howard, E. W. Beier, J. Farine, R. L. Hahn, M. C. Browne, A. J. Noble, L. C. Stonehill, S. McGee, J. M. Wouters, A. B. McDonald, Christopher C. M. Kyba, B. L. Wall, B. T. Cleveland, H. M. O'Keeffe, Keith Rielage, Jocelyn Monroe, B. Aharmim, B. Beltran, A. L. Hallin, C. Mifflin, N. S. Oblath, C. B. Krauss, M. R. Dragowsky, B. A. VanDevender, N. Tolich, Guthrie Miller, B. Morissette, Benjamin Monreal, E. D. Earle, G. C. Harper, F. A. Duncan, J. A. Secrest, I. T. Lawson, D. Waller, G. A. Cox, H. Fergani, and T. Tsui

Subjects
Physics, Nuclear and High Energy Physics, Sudbury Neutrino Observatory, Solar energetic particles, 010308 nuclear & particles physics, Solar neutrino, Cosmic ray, 01 natural sciences, 7. Clean energy, Nuclear physics, 0103 physical sciences, Neutrino, 010306 general physics, Neutrino oscillation, Charged current, Lepton
Abstract

This paper details the solar neutrino analysis of the 385.17-day phase-III data set acquired by the Sudbury Neutrino Observatory (SNO). An array of He-3 proportional counters was installed in the heavy-water target to measure precisely the rate of neutrino-deuteron neutral-current interactions. This technique to determine the total active B-8 solar neutrino flux was largely independent of the methods employed in previous phases. The total flux of active neutrinos was measured to be 5.54(-0.31)(+0.33)(stat.)(-0.34)(+0.36)(syst.) x 10(6) cm(-2) s(-1), consistent with previous measurements and standard solar models. A global analysis of solar and reactor neutrino mixing parameters yielded the best-fit values of Delta m(2) = 7.59(-0.21)(+0.19) x 10(-5) eV(2) and theta = 34.4(-1.2)(+1.3) degrees. DOI: 10.1103/PhysRevC.87.015502

Published
2013
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58. Dark matter search project PICO-LON

Author

Kunio Inoue, Tatsushi Shima, Y. Teraoka, A. Kozlov, H. Ejiri, H. Ikeda, Reiko Orito, G. Kanzaki, Sei Yoshida, K. Imagawa, K. Yasuda, Y. Takemoto, Ryuta Hazama, Saori Umehara, and Ken-Ichi Fushimi

Subjects
Physics, History, Cold dark matter, Physics - Instrumentation and Detectors, 010308 nuclear & particles physics, Dark matter, Radiochemistry, FOS: Physical sciences, Instrumentation and Detectors (physics.ins-det), Scintillator, 01 natural sciences, Computer Science Applications, Education, Volume (thermodynamics), Impurity, 0103 physical sciences, Graphite crucible, Ingot, Astrophysics - Instrumentation and Methods for Astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM), 010303 astronomy & astrophysics
Abstract

The PICO-LON project aims at search for cold dark matter by means of highly radio-pure and large volume NaI(Tl) scintillator. The NaI powder was purifed by chemical processing to remove lead isotopes and selecting a high purity graphite crucible. The concentrations of radioactive impurities of $^{226}$Ra and $^{228}$Th were effectively reduced to 58$\pm$4 $\mu$Bq/kg and 1.5$\pm$1.9 $\mu$Bq/kg, respectively. It should be remarked that the concentration of $^{210}$Pb, which is crucial for the sensitivity to dark matter, was reduced to 24$\pm$2 $\mu$Bq/kg. The total background rate at 10 keVee was as low as 8 keV$^{-1}$kg$^{-1}$day$^{-1}$, which was sufficiently low to search for dark matter. Further purification of NaI(Tl) ingot and future prospect of PICO-LON project is discussed., Comment: Submitted to Proceedings of TAUP 2015

Published
2016

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

Author

Masaharu Nomachi, T. Batpurev, S. Ajimura, Y. Tamagawa, T. Ohata, W. M. Chan, X. Li, B. T. Khai, K. Morishita, K. Matsuoka, S. Noshiro, Saori Umehara, Izumi Ogawa, K. Nakajima, Takashi Iida, Tadafumi Kishimoto, H. Kakubata, Sei Yoshida, V. T. T. Trang, A. Masuda, K. Suzuki, Ken-Ichi Fushimi, Ryuta Hazama, T. Uehara, K Tesuno, N. Nakatani, Toshihiro Maeda, and H. Osumi

Subjects
Physics, History, Physics::Instrumentation and Detectors, Astrophysics::High Energy Astrophysical Phenomena, Detector, Scintillator, Computer Science Applications, Education, Nuclear physics, MAJORANA, Neutron capture, Double beta decay, High Energy Physics::Experiment, Neutron, Light emission, Neutrino
Abstract

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

Published
2016
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60. Double Beta Decays of116Cd

Author

Yuri Zdesenko, Toshio Senoo, Hirokazu Sano, Nobuyuki Kudomi, Koichiro Nagata, Michio Kawasaki, Ryuta Hazama, Kenji Okada, Hideaki Ohsumi, Kyo Kume, Ken-Ichi Fushimi, Jun-ichi Tanaka, Vasiliy Kouts, Hiroyasu Ejiri, T. Shibata, and Tatsushi Shima

Subjects
Physics, Quenching (fluorescence), Isotopes of cadmium, Double beta decay, Beta particle, General Physics and Astronomy, Beta (velocity), Neutrino, Atomic physics, Ground state, Radioactive decay
Abstract

Double beta decays (ββ) from the 0 + ground state in 116 Cd to the 0 + ground state in 116 Sn were studied by means of ELEGANT V. A finite half-life for the two-neutrino ββ(2νββ) and an upper limit on the neutrinoless one (0νββ) were obtained as T 2ν 1/2 =2.6 +0.9 -0.5 ×10 19 y and T 0ν 1/2 >6.3×10 21 y (68% C.L.), respectively. The nuclear matrix element M 2ν ββ was deduced as 0.069±0.009 in units of ( m e c 2 ) -1 . This supports the universal quenching of the 2νββ rates in this mass region, which is consistent with that previously measured in 100 Mo.

Published
1995
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61. Search for neutrino-less double beta decay with CANDLES

Author

S. Maeda, Koichi Ichimura, N. Nakatani, Saori Umehara, W. M. Chan, K. Okada, A. Kawamura, S. Tomita, W. Wang, G. Fujita, H. Kakubata, T. Harada, Ken-Ichi Fushimi, A. Yamamoto, Masaharu Nomachi, Tadafumi Kishimoto, J. Takemoto, Ryuta Hazama, S. Ueno, K. Suzuki, Izumi Ogawa, S. Ajimura, K. Matsuoka, Y. Tamagawa, M. Doihara, G. Ito, Sei Yoshida, M. Saka, and H. Ohsumi

Subjects
Physics, Nuclear physics, MAJORANA, Particle physics, Physics::Instrumentation and Detectors, Astrophysics::High Energy Astrophysical Phenomena, Double beta decay, High Energy Physics::Phenomenology, Detector, High Energy Physics::Experiment, Astrophysics::Cosmology and Extragalactic Astrophysics, Neutrino
Abstract

CANDLES is the project to search for neutrino-less double beta decay (0νββ) of βCa. The observation of 0νββ will prove existence of a massive Majorana neutrino. Now we installed new detector system CANDLES III. Here expected performances of the system for background rejection are presented. It is also described current status of development for the detector system.

Published
2012
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62. Double beta decays of 116Cd

Author

K. Kawasaki, H. Ohsumi, Junki Tanaka, Kyo Kume, Keitaro Nagata, K. Okada, Nobuyuki Kudomi, V. Koutz, H. Sano, T.-A. Shibata, T. Senoo, Ryuta Hazama, Ken-Ichi Fushimi, Hiroyasu Ejiri, Yu.G. Zdesenko, Tatsushi Shima, and V. Malishko

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Beta (finance)
Published
1994
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63. Spin-isospin excitations in nuclei via (3He,t) reactions at 450 MeV

Author

J. W. Jänecke, Hidetoshi Akimune, Hiroyasu Ejiri, Momoko Tanaka, Mamoru Fujiwara, Ryuta Hazama, M. Yosoi, Hidenori Toyokawa, Atsushi Tamii, M.N. Harakeh, Kyo Kume, M. B. Greenfield, K. Shinmyo, I. Daito, Yoshitaka Fujita, Nobuyuki Kudomi, Shintaro Nakayama, and T. Inomata

Subjects
Physics, Nuclear and High Energy Physics, Solar neutrino, Nuclear Theory, Resolution (electron density), Measure (mathematics), Volume integral, Nuclear physics, Excited state, Isospin, Atomic physics, Nuclear Experiment, Spin (physics), Neutrino oscillation
Abstract

Spin-isospin excitations in nuclei have been studied by means of the ( 3 He,t) reactions at 450 MeV. The Gamow-Teller (GT) resonances are found to be strongly excited. A fine structure of the giant Gamow Teller resonances in medium-heavy nuclei is observed with an energy resolution of 130 keV. The volume integrals of the effective interactions J στ and J τ have been determined experimentally. The importance of high resolution observation of the ( 3 He,t) reactions at intermediate energies, both, to study the double β decay processes and to measure the detection sensitivities for solar neutrino experiments is discussed.

Published
1994
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64. Double beta decays studied by ELEGANTS V

Author

Junki Tanaka, Keitaro Nagata, Kei Okada, Ken-Ichi Fushimi, Nobuyuki Kudomi, H. Ohsumi, Hiroyasu Ejiri, and Ryuta Hazama

Subjects
Nuclear physics, Physics, Nuclear and High Energy Physics, X-ray spectroscopy, Decay scheme, Isotopes of germanium, Double beta decay, Half-life, Beta (velocity), Neutrino, Atomic physics, Atomic and Molecular Physics, and Optics, Beta-decay stable isobars
Abstract

Nuclear and particle rare decay and weak processes were studied by high sensitivity β-γ and X ray spectrometer ELEGANTS V. Double beta decays of 100Mo, 116Cd were studied in Kamioka underground laboratory. A finite value of half life for the two neutrino double beta decay of 100Mo (T122v = 1.5−0.20+0.30 × 1019yr) and the lower limit for neutrino less double beta decay (T120v > 7 × 1021yr) for 100Mo were obtained. Double beta decays of 116Cd has also been studied. The half life for the two neutrino double beta decay (T122v = 2.2−0.4+0.7 × 1019yr) and the lower limit for neutrino less double beta decay (T120v > 1.7 × 1021yr) were obtained.

Published
1994
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65. Limits on single- and multinucleon decays inI127by inclusive measurements of nuclear γ and x rays

Author

H. Ohsumi, Ken-Ichi Fushimi, H. Ejiri, and Ryuta Hazama

Subjects
Baryon, Physics, Nuclear physics, Nuclear and High Energy Physics, Particle physics, Proton, Double beta decay, Hadron, Neutron, Elementary particle, Nucleon, Beta decay
Abstract

Baryon-number-violating nucleon decays were studied by searching for x and [gamma] rays associated with radioactive residual nuclei produced by single- and multinucleon decays in [sup 127]I. Large volume NaI(Tl) detectors were used for the study. New lower limits of [tau]([ital n])[gt]4.7[times]10[sup 24] yr and [tau]([ital p])[gt]3.0[times]10[sup 24] yr were obtained on the mode-independent mean lives for the neutron and proton decays in [sup 127]I, respectively. Lower limits of [tau]([ital nn])[gt]2.1[times]10[sup 24] yr, [tau]([ital nnn])[gt]1.8[times]10[sup 23] yr, and [tau]([ital nnnn])[gt]1.4[times]10[sup 23] yr were deduced for the first time on the mode-independent mean lives for dineutron, trineutron, and tetraneutron decays in [sup 127]I, respectively.

Published
1994
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66. Study of neutrino and dark matter by high sensitivity ββ, γ and X ray spectrometer ELEGANTS

Author

Kyo Kume, Ryuta Hazama, Ken-Ichi Fushimi, Nobuyuki Kudomi, H. Ohsumi, Junki Tanaka, Keitaro Nagata, H. Ejiri, Yu.G. Zdesenko, and Kei Okada

Subjects
Physics, Nuclear physics, Elastic scattering, Nuclear and High Energy Physics, Cold dark matter, Double beta decay, Dark matter, Half-life, High Energy Physics::Experiment, Inelastic scattering, Neutrino, Scintillator
Abstract

Nuclear and particle rare decay and weak processes were studied by high sensitivity β-γ and X ray spectrometer ELEGANTS V. A finite value of half life for the two neutrino double beta decay of 100Mo ( T 1 2 2ν = 1.15 −0.20 +0.30 × 10 19 yr ) and the lower limit for neutrino less double beta decay ( T 1 2 0ν > 7 × 10 21 yr ) for 100Mo were obtained. Double beta decays of 116Cd has also been studied. The preliminaly half life for the two neutrino double beta decay ( T 1 2 2ν = 2.6 −0.6 +1.3 × 10 19 yr ) and the lower limit for neutrino less double beta decay ( T 1 2 0ν > 1.1 × 10 21 yr ) were obtained. The large volume NaI(Tl) scintillators in ELEGANTS V have been applied to search for cosmic cold dark matter candidates. The elastic scattering and inelastic scattering of dark matter and the nuclei in the NaI(Tl) scintillator were studied. The low back ground (⋍5/day/keV/kg) and low noise (⋍5keV) experiment was successfully done and stringent limit on the local density of dark matter candidates was given.

Published
1994
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67. The MAJORANA DEMONSTRATOR: A Search for Neutrinoless Double-beta Decay of Germanium-76

Author

J. Esterline, Keith Rielage, M. L. Miller, A. W. P. Poon, R. D. Martin, V. G. Egorov, R. G. H. Robertson, Yu. Efremenko, Nicole R. Overman, D. G. Phillips, V. E. Guiseppe, L. Mizouni, M. C. Ronquest, A. Knecht, O.I. Kochetov, Keenan Thomas, V. B. Brudanin, G. K. Giovanetti, Tatsushi Shima, C.-H. Yu, B. H. LaRoque, J. C. Loach, James E. Fast, C. D. Christofferson, S. R. Elliott, V. V. Timkin, J. Strain, R. A. Johnson, G. Perumpilly, S. I. Konovalov, D. Steele, V. M. Gehman, K. Vorren, Yuen-Dat Chan, M. P. Green, M. Shirchenko, Dongming Mei, F. M. Fraenkle, Brian D. LaFerriere, M. F. Kidd, John L. Orrell, H. Ejiri, A. L. Hallin, Werner Tornow, I. Vanyushin, Matthew Busch, A. S. Barabash, Richard T. Kouzes, D. C. Radford, Masaharu Nomachi, Kai Vetter, K. Gusey, M. A. Howe, K. J. Snavely, J. R. Beene, F. E. Bertrand, Jonathan D. Leon, M. Boswell, Ryuta Hazama, M. Bergevin, G. Prior, E. Yakushev, Reynold J. Cooper, L. E. Leviner, N. Fields, Eric W. Hoppe, J. H. Merriman, Vladimir Yumatov, Stanley M. Howard, A. R. Young, Michael G. Marino, J. A. Detwiler, E. Aguayo, D. C. Combs, Chao Zhang, J. F. Wilkerson, P. Finnerty, S. MacMullin, Alexis G. Schubert, J. I. Collar, Henning O. Back, C. Keller, F. T. Avignone, R. L. Varner, Reyco Henning, P. J. Doe, M. Horton, and K. J. Keeter

Subjects
Physics, History, Particle physics, Physics::Instrumentation and Detectors, Detector, Dark matter, FOS: Physical sciences, chemistry.chemical_element, Germanium, Computer Science Applications, Education, MAJORANA, WIMP, chemistry, Double beta decay, High Energy Physics::Experiment, Nuclear Experiment (nucl-ex), Neutrino, Tonne, Nuclear Experiment
Abstract

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 76-Ge. The DEMONSTRATOR will contain 40 kg of germanium; up to 30 kg will be enriched to 86% in 76-Ge. 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 76-Ge neutrinoless double-beta decay Q-value of 2039 keV., Submitted to AIP Conference Proceedings, 19th Particles & Nuclei International Conference (PANIC 2011), Massachusetts Institute of Technology, Cambridge, MA, USA, July 24-29, 2011; 3 pages, 1 figure

Published
2011

68. The Majorana Experiment

Author

M. Shirchenko, D. C. Combs, J. H. Merriman, John L. Orrell, Albert Young, Eric W. Hoppe, V. Sobolev, Michael G. Marino, A. S. Barabash, V. G. Egorov, Martin E. Keillor, E. Yakushev, Jonathan D. Leon, B. H. LaRoque, K. Gusey, Yu. Efremenko, N. Fields, Matthew Busch, P. J. Doe, Alexis G. Schubert, G. Perumpilly, F. M. Fraenkle, M. C. Ronquest, V. M. Gehman, D. G. Phillips, James E. Fast, J. A. Detwiler, J. F. Wilkerson, M. P. Green, M. Horton, P. Finnerty, M. L. Miller, Masaharu Nomachi, B. A. Wolfe, Vladimir Yumatov, K. J. Keeter, J. I. Collar, Stanley M. Howard, H. Ejiri, A. W. P. Poon, Andrew Hime, S. MacMullin, Dongming Mei, S. I. Konovalov, R. D. Martin, Henning O. Back, C. D. Christofferson, Richard T. Kouzes, C. Keller, G. K. Giovanetti, Keith Rielage, R. A. Johnson, S. R. Elliott, R. G. H. Robertson, L. Mizouni, Kai Vetter, K. Vorren, Werner Tornow, D. C. Radford, F. E. Bertrand, C.-H. Yu, M. Boswell, Ryuta Hazama, Nicole R. Overman, L. E. Leviner, K. J. Snavely, V. V. Timkin, I. Vanyushin, Brian D. LaFerriere, G. Prior, Jeremy D. Kephart, J. Strain, V. E. Guiseppe, D. Steele, F. T. Avignone, E. Aguayo, Yuen-Dat Chan, R. L. Varner, Reyco Henning, A. Knecht, O.I. Kochetov, J. Esterline, Keenan Thomas, J. C. Loach, M. A. Howe, Chao Zhang, M. F. Kidd, M. Bergevin, Tatsushi Shima, A. L. Hallin, Reynold J. Cooper, and V. B. Brudanin

Subjects
Nuclear physics, Physics, Particle physics, MAJORANA, Double beta decay, Elementary particle, Invariant mass, Fermion, Neutrino, Radioactive decay, Lepton
Abstract

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

Published
2011
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69. Double beta decays of 100Mo by ELEGANT V at Oto Cosmo Observatory

Author

K. Takahisa, H. Ohsumi, Ken-Ichi Fushimi, H. Kuramoto, Nobuyuki Kudomi, T. Kishimoto, Kyo Kume, K. Hayashi, Yasuhiro Tsujimoto, T. Matsuoka, Ryuta Hazama, H. Ejiri, and S. Yoshida

Subjects
Physics, Nuclear physics, Nuclear and High Energy Physics, Particle physics, Observatory, Double beta decay, Beta (velocity), Atomic and Molecular Physics, and Optics
Abstract

Exclusive measurements of neutrino-less double beta decays (0νββ) of 100 Mo were made by means of ELEGANT V. The present status of the double beta decay experiment with ELEGANT V is presented. The data at Oto lab., being combined with the data at Kamioka, gives stringent limits on half-lives for 0νββ and 〈 m ν 〉

Published
2000
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70. Solubility, Light Output and Energy Resolution Studies of Molybdenum-Loaded Liquid Scintillators

Author

D.I. Will, Ryuta Hazama, R. G. H. Robertson, Hroyasu Ejiri, V.M. Gehman, and P. J. Doe

Subjects
Nuclear and High Energy Physics, Physics - Instrumentation and Detectors, Organo-metallic chemistry, Physics::Instrumentation and Detectors, chemistry.chemical_element, FOS: Physical sciences, Particle detectors, Scintillator, Particle detector, Nuclear physics, Double beta decay, Neutrino, Solubility, Nuclear Experiment (nucl-ex), Instrumentation, Nuclear Experiment, Physics, business.industry, Detector, Molybdenum, Liquid scintillator, Instrumentation and Detectors (physics.ins-det), chemistry, Neutrino detector, Optoelectronics, Neutrinoless double-beta decay, High Energy Physics::Experiment, business
Abstract

The search for neutrinoless double-beta decay is an important part of the global neutrino physics program. One double-beta decay isotope currently under investigation is 100Mo. In this article, we discuss the results of a feasibility study investigating the use of molybdenum-loaded liquid scintillator. A large, molybdenum-loaded liquid scintillator detector is one potential design for a low-background, internal-source neutrinoless double-beta decay search with 100Mo. The program outlined in this article included the selection of a solute containing molybdenum, a scintillating solvent and the evaluation of the mixture's performance as a radiation detector., 8 pages, 3 figures

Published
2009

72. Neutrino-less double-βdecay ofCa48studied byCaF2(Eu) scintillators

Author

D. Yokoyama, K. Matsuoka, Y. Tatewaki, Tadamitsu Kishimoto, K. Mukaida, K. Kishimoto, S. Yoshida, Saori Umehara, Hideyuki Sakai, S. Tomii, Ryuta Hazama, H. Miyawaki, A. Yanagisawa, T. Kobayashi, Izumi Ogawa, and Atsunari Katsuki

Subjects
Physics, Nuclear physics, Nuclear and High Energy Physics, Scintillator, Neutrino, Lower limit
Abstract

We searched for the neutrino-less double-β decay(0νββ) of 48 Ca by using CaF 2 (Eu) scintillators. Analysis of their pulse shapes was effective to reduce backgrounds. No events are observed in the Q ββ value region for the data of 3394 kg day. It gives a lower limit (90% confidence level) of T 0νββ ½ > 2.7 x 10 22 year for the half-life of 0νββ of 48 Ca. Combined with our previous data for 1553 kg day [I. Ogawa et al., Nucl. Phys. A730, 215 (2004)], we obtained a more stringent limit of T 0νββ ½ > 5.8 × 10 22 year.

Published
2008
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73. MOON for neutrino-less double beta decays

Author

A. N. Sissakian, P. Kavitov, J. F. Wilkerson, Jonathan Engel, Vladimir Vaturin, Masaharu Nomachi, S. R. Elliott, Sei Yoshida, R. G. H. Robertson, V. Voronov, Tatsushi Shima, Vladimir Kekelidze, Ken-Ichi Fushimi, Grigori Shirkov, P. J. Doe, Hidehito Nakamura, V. M. Gehman, Saori Umehara, H. Ejiri, M. Finger, M. Slunečka, M. B. Greenfield, Ryuta Hazama, Vaclav Vrba, D.I. Will, and Alexander I. Titov

Subjects
Physics, Particle physics, Physics::Instrumentation and Detectors, Solar neutrino, Detector, General Physics and Astronomy, Scintillator, Nuclear physics, Massless particle, MAJORANA, Double beta decay, Scintillation counter, High Energy Physics::Experiment, General Materials Science, Physical and Theoretical Chemistry, Neutrino
Abstract

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

Published
2008
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74. DIRECT SEARCH FOR SPIN-DEPENDENT WIMPS WITH <font>CaF</font>2 DETECTOR

Author

Y. Tatewaki, N. Suzuki, Yukichi Tanaka, S. Ajimura, D. Yokoyama, M. Itamura, S. Tomii, H. Sakai, K. Matsuoka, Tadafumi Kishimoto, Atsunari Katsuki, S. Yoshida, Y. Ishikawa, S. Shiomi, Ryuta Hazama, Izumi Ogawa, K. Mukaida, H. Miyawaki, K. Kishimoto, K. Ichihara, T. Nitta, Yoshiyuki Hirano, and S. Umehara

Subjects
Physics, Nuclear physics, Particle physics, Detector, Direct search, Scintillator, Spin-½
Published
2008
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75. Determination of theνeand totalB8solar neutrino fluxes using the Sudbury Neutrino Observatory Phase I data set

Author

M. Huang, R. U. Haq, C. B. Krauss, N. S. Oblath, Malcolm M. Fowler, J. Wendland, F. A. Duncan, J. A. Dunmore, H. Fergani, N.W. Tanner, K. Kazkaz, W. B. Handler, R. J. Ford, G. Jonkmans, A. P. Ferraris, J. X. Wang, S. J. M. Peeters, B. Aharmim, M. W.E. Smith, A. S. Hamer, Y. I. Tserkovnyak, J. F. Wilkerson, K. McFarlane, T. J. Walker, R. MacLellan, G. McGregor, G. Prior, M. Bercovitch, J. A. Formaggio, Reda Tafirout, Darren Grant, Benjamin Monreal, C. Jillings, C. A. Duba, B. Jamieson, N. West, Q. R. Ahmad, N. Tagg, E. D. Earle, B. L. Wall, F. Dalnoki-Veress, V. L. Rusu, G. Milton, W. F. Davidson, W. J. Heintzelman, J. Boger, H. W. Lee, P. T. Trent, R. G. Stokstad, C. J. Virtue, R. L. Hahn, H. Mes, Salvador Gil, J. A. Secrest, J. C. Barton, I. T. Lawson, H. S. Ng, T. Tsui, R. J. Boardman, L. C. Stonehill, P. Jagam, J. G. Hykaway, G. A. Cox, J. D. Anglin, Minfang Yeh, K. T. Lesko, M. C.P. Isaac, M. DiMarco, L. L. Kormos, Steven Elliott, F. M. Newcomer, S. D. Reitzner, S. N. Ahmed, Keith Rielage, T. J. Bowles, Monica Dunford, J. Maneira, A. Krüger, R. G. Van de Water, Peter Wittich, J. T.M. Goon, A. W. P. Poon, T. V. Bullard, B. C. Robertson, M. Moorhead, J. Cameron, J. C. Loach, N. A. Jelley, M. Thorman, H. M. O'Keeffe, G. Doucas, Yuen-Dat Chan, R. W. Ollerhead, M. Kos, X. Chen, J. Lyon, J. B. Wilhelmy, K. Graham, S. M. Oser, E. D. Hallman, T. Kutter, R. Meijer Drees, A. Schülke, A. L. Hallin, C. Mifflin, H. Wan Chan Tseung, G. T. Ewan, J. H.M. Cowan, R. K. Taplin, E. W. Beier, John L. Orrell, R. S. Storey, S. D. Biller, H. Labranche, Bernie G. Nickel, M.G. Boulay, D. L. Wark, J. Bigu, B. Morrissette, S. J. Brice, C. Kraus, I. Levine, A. Goldschmidt, P. J. Harvey, N. Tolich, S. S.E. Rosendahl, J. R. Leslie, B. A. Moffat, P. M. Thornewell, A. D. Marino, J. M. Wouters, Hal Evans, M. Lay, Reyco Henning, Y. Takeuchi, C. K. Hargrove, K. K.S. Miknaitis, M. R. Dragowsky, E. Guillian, T. C. Andersen, P. T. Keener, H. B. Mak, A. B. McDonald, H. Seifert, Christopher C. M. Kyba, N. Gagnon, J. J. Simpson, Klaus Kirch, E. Saettler, C. E. Okada, J. D. Hepburn, E. D. Frank, Herbert H. Chen, N. Starinsky, P. J. Doe, M. H. Schwendener, E. Bonvin, David A. Sinclair, S. McGee, J. Heise, F. Fleurot, S. Luoma, R. J. Komar, R. C. Allen, H. Heron, A. Roberge, P. Skensved, H. Deng, D. S. McDonald, D. F. Cowen, J. Law, V. M. Novikov, C. J. Sims, J. V. Germani, I. Blevis, M. Omori, J. Hewett, Andrew Hime, Kai Zuber, C. D. Tunnell, X. Dai, R. Lange, Mark Neubauer, M. G. Bowler, M. C. Browne, R. L. Helmer, M. Shatkay, C. Howard, C. W. Nally, J. Farine, Alan R. Smith, A. J. Noble, T.H. Burritt, G. Bühler, R. A. Black, J. K. Rowley, Joshua R. Klein, R. A. Ott, W. Locke, B. T. Cleveland, W. Frati, J. R. Wilson, A. B. Knox, Bhaskar Sur, Richard T. Kouzes, M. Bergevin, N. McCauley, C. A. Currat, R. Van Berg, K. Frame, E. B. Norman, K. M. Heeger, A. Wright, R. D. Martin, R. G. H. Robertson, T. D. Steiger, Chris Waltham, M. L. Chen, A. A. Hamian, Ryuta Hazama, M. L. Miller, S. Majerus, and M. A. Howe

Subjects
Physics, Elastic scattering, Nuclear and High Energy Physics, Sudbury Neutrino Observatory, Particle physics, Neutral current, 010308 nuclear & particles physics, Solar neutrino, media_common.quotation_subject, Cosmic ray, 01 natural sciences, 7. Clean energy, Asymmetry, Nuclear physics, 13. Climate action, 0103 physical sciences, Neutrino, 010306 general physics, Charged current, media_common
Abstract

This article provides the complete description of resultsfrom the Phase I data set of the Sudbury Neutrino Observatory (SNO). ThePhase I data set is based on a 0.65 kt-year exposure of heavy water tothe solar 8B neutrino flux. Included here are details of the SNO physicsand detector model, evaluations of systematic uncertainties, andestimates of backgrounds. Also discussed are SNO's approach tostatistical extraction of the signals from the three neutrino reactions(charged current, neutral current, and elastic scattering) and theresults of a search for a day-night asymmetry in the ?e flux. Under theassumption that the 8B spectrum is undistorted, the measurements fromthis phase yield a solar ?e flux of ?(?e) =1.76+0.05?0.05(stat.)+0.09?0.09 (syst.) x 106 cm?2 s?1, and a non-?ecomponent ?(? mu) = 3.41+0.45?0.45(stat.)+0.48?0.45 (syst.) x 106 cm?2s?1. The sum of these components provides a total flux in excellentagreement with the predictions of Standard Solar Models. The day-nightasymmetry in the ?e flux is found to be Ae = 7.0 +- 4.9 (stat.)+1.3?1.2percent (sys.), when the asymmetry in the total flux is constrained to bezero.

Published
2007
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76. PICO-LON Project for WIMPs search

Author

Masaharu Nomachi, Ryuta Hazama, Kensuke Yasudai, Yuuki Kamedai, K. Imagawa, Hidehito Nakamura, Norihiko Koori, Saori Umehara, Hiroshi Ito, Shintaro Nakayama, Sei Yoshida, Ken-Ichi Fushimi, K. Ichihara, Tatsushi Shima, and Hiroyasu Ejiri

Subjects
Physics, History, Optics, business.industry, Observatory, Dark matter, FOS: Physical sciences, Scintillator, Nuclear Experiment (nucl-ex), business, Nuclear Experiment, Computer Science Applications, Education
Abstract

Highly segmented inorganic crystal has been shown to have good performance for dark matter search. The energy resolution of ultra thin and large area NaI(Tl) scintillator has been developed. The estimated sensitivity for spin-dependent excitation of 127I was discussed. The recent status of low background measurement at Oto Cosmo Observatory is reported, Comment: 3 pages, 1 figure, Proceedings of TAUP2007

Published
2007
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78. WIMPs search by means of the highly segmented scintillator

Author

Y. Shichijo, K. Ichihara, R. Hayami, Shintaro Nakayama, Ken-Ichi Fushimi, M. Toi, Ryuta Hazama, Saori Umehara, E. Aihara, Norihiko Koori, S. Yoshida, and H. Kawasuso

Subjects
Physics, business.industry, Detector, Dark matter, Astrophysics (astro-ph), General Physics and Astronomy, FOS: Physical sciences, Astrophysics, Scintillator, Signal selection, Highly sensitive, Optics, Sensitivity (control systems), business
Abstract

The highly sensitive method to search for WIMPs dark matter particles is proposed. An array of thin NaI(Tl) plate has the great selectivity for distinguishing the WIMPs events and background ones. The principle of signal selection for WIMPs is described. The high sensitivity for SD (spin-dependent) type WIMPs is expected by applying multi-layer system of NaI(Tl) detector., Comment: 11 pages, added some sentences to make the arguments clear

Published
2005
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79. Low Radioactivity in CANDLES

Author

K. Ichihara, Izumi Ogawa, Saori Umehara, A. Yanagisawa, Tadafumi Kishimoto, Ryuta Hazama, D. Yokoyama, Yoshiyuki Hirano, K. Matsuoka, Y. Tatewaki, S. Yoshida, K. Mukaida, S. Ajimura, K. Kishimoto, and H. Sakai

Subjects
Nuclear physics, Physics, Particle physics, Decay scheme, Isotopes of germanium, Branching fraction, Double beta decay, Beta particle, Isotopes of zirconium, High Energy Physics::Experiment, Radioactive decay, Beta-decay stable isobars
Abstract

CANDLES is the project to search for double beta decay of 48Ca by using CaF2 crystals. Double beta decay of 48Ca has the highest Q value among all nuclei whose double beta decay is energetically allowed. This feature makes the study almost background free and becomes important once the study is limited by the backgrounds. We studied double beta decays of 48Ca by using ELEGANTS VI detector system which features CaF2(Eu) crystals. We gave the best limit on the lifetime of neutrino‐less double beta decay of 48Ca although further development is vital to reach the neutrino mass of current interest for which CANDLES is designed. In this article we present how CANDLES can achieve low radioactivity, which is the key for the future double beta decay experiment.

Published
2005
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80. Limits on axial coupled dark matters studied by inelastic scattering from 127I in NaI

Author

Kyo Kume, H. Ohsumi, Ryuta Hazama, Hiroyasu Ejiri, Nobuyuki Kudomi, K. Hayashi, and Ken-Ichi Fushimi

Subjects
Momentum, Physics, Nuclear physics, Nuclear and High Energy Physics, Recoil, Monte Carlo method, Dark matter, Inelastic scattering, Atomic physics, Deep inelastic scattering, Atomic and Molecular Physics, and Optics, Excitation, Inelastic neutron scattering
Abstract

Axial-vector (spin-coupled) excitation of 127 I by inelastic scattering of dark matter (DM) was studied to search for spin-coupled DM. In the present work, the inelastic peak was precisely analyzed. The peak spread and shift due to the recoil momentum was precisely estimated by Monte Carlo simulation. A new stringent limit on the spin-coupled DM was obtained.

Published
1996
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81. 0vββ Decays of 100Mo by means of ELEGANT V

Author

Tatsushi Shima, Ken-Ichi Fushimi, Kei Okada, H. Ohsumi, K. Shinmyo, Ryuta Hazama, T. Nitta, H. Ejiri, Junki Tanaka, Keitaro Nagata, K. Hayashi, Nobuyuki Kudomi, and Kyo Kume

Subjects
Nuclear and High Energy Physics, Right handed, Beta (velocity), Geometry, Atomic physics, Ground state, Atomic and Molecular Physics, and Optics, Lower limit, Majoron, Mathematics
Abstract

Exclusive measurements of neutrino-less double beta decays(0vββ) of 100Mo were made by means of ELEGANT V. Most stringent lower limits on the half-lives were obtained for the 0vββ ground state transition as T1/20v(mv) > 5.2 × 1022y, T1/20v(λ) > 3.9 × 1022y and T1/20v(η) > 5.1 × 1022y, for the mass term 〈mv〉 and the right handed current terms of 〈λ〉 and 〈η〉, respectively. The most stringent lower limit on the 0vββB followed by Majoron(B) was derived as T1/20vB > 5.4 × 1021 y. These lead to the upper limits of 〈mv〉

Published
1996
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82. WIMPS SEARCH AT OTO COSMO OBSERVATORY

Author

Izumi Ogawa, Y. Ishikawa, Nobuyuki Kudomi, Y. Shichijo, Kyo Kume, Norihiko Koori, S. Shiomi, K. Matsuoka, N. Suzuki, M. Itamura, Shintaro Nakayama, Yukichi Tanaka, K. Ichihara, S. Umehara, Y. Yanagida, K. Takahisa, Hiroyasu Ejiri, S. Ajimura, K. Fushimi, Ryuta Hazama, H. Miyawaki, Tadafumi Kishimoto, S. Yoshida, H. Ohsumi, and G. Kunitomi

Subjects
Physics, Observatory, Dark matter, Astronomy, Astrophysics
Published
2003
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83. Search for exotic nuclear transition by using the large volume NaI detector of ELEGANTS V

Author

Ken-Ichi Fushimi, Hiroyasu Ejiri, H. Ohsumi, Junki Tanaka, Keitaro Nagata, Nobuyuki Kudomi, Ryuta Hazama, and Kei Okada

Subjects
Physics, Nuclear and High Energy Physics, Physics::Instrumentation and Detectors, Dark matter, Detector, Astrophysics::Cosmology and Extragalactic Astrophysics, Inelastic scattering, Scintillator, Neutron scattering, Atomic and Molecular Physics, and Optics, Nuclear physics, Recoil, Halo, Atomic physics, Spin (physics)
Abstract

The authors studied elastic and inelastic scattering of dark matter with nuclei in huge NaI(Tl) scintillator. The light output response f was measured by fast neutron scattering. The result was f I = 0.05 ± 0.02 for I recoil and f Na = 0.4 ± 0.2 for Na recoil. The low noise (≅5keV) and low BG (≅8counts/day/keV/kg) was achieved by huge (36.5kg/module) NaI(Tl) scintillator. Strong limit for inelastic exitation of 127 I nuclei was studied and strong limit on the local halo density of spin coupled dark matter candidate was derived.

Published
1994
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85. Direct Evidence for Neutrino Flavor Transformation from Neutral-Current Interactions in SNO

Author

T. V. Bullard, M. H. Schwendener, B. C. Robertson, E. W. Beier, H. Fergani, G. Doucas, J. M. Wouters, H. W. Lee, J. Law, H. S. Ng, D. L. Wark, P. J. Doe, A. R. Smith, K. McFarlane, J. B. Wilhelmy, T. Kutter, Guthrie Miller, J.D. Anglin, A. S. Hamer, Q. R. Ahmad, C. J. Sims, J. V. Germani, M. Moorhead, R. Meijer Drees, J. Cameron, A. B. McDonald, H. Heron, F. Dalnoki-Veress, Min Chen, A. D. Marino, Christopher C. M. Kyba, John Heise, R. U. Haq, N. McCauley, K. Kazkaz, T. J. Radcliffe, R. G. H. Robertson, M. R. Dragowsky, E. Saettler, R. J. Boardman, T. Spreitzer, G. A. Cox, Andrew Hime, W. B. Handler, J.L. Hewett, Herbert H. Chen, Jochen Klein, Ilan Levine, C. J. Virtue, M. W.E. Smith, I. Lawson, N. Tagg, Anett Schulke, S. J. Brice, J. Bigu, Chris Waltham, A. J. Noble, Y. I. Tserkovnyak, R. L. Hahn, Salvador Gil, G. McGregor, J. G. Hykawy, Yuen-Dat Chan, A. P. Ferraris, J. X. Wang, E. D. Earle, A. L. Hallin, C. Mifflin, B. T. Cleveland, X. Chen, N.W. Tanner, K. Graham, L. C. Stonehill, S. M. Oser, J. Farine, Minfang Yeh, G. Jonkmans, N. West, V. L. Rusu, P. Skensved, M. Lay, R. K. Taplin, F. A. Duncan, J. H.M. Cowan, M. G. Boulay, W. J. Heintzelman, J. C. Barton, N. A. Jelley, M. Thorman, R. A. Black, M. O'Neill, J. J. Simpson, P. T. Keener, R. J. Ford, D. F. Cowen, Monica Dunford, J. Maneira, F. M. Newcomer, A. W. P. Poon, G. Bühler, J. A. Dunmore, A. Knox, P. T. Trent, R. W. Ollerhead, Peter Wittich, J. Lyon, M. C.P. Isaac, R. G. Stokstad, N. Gagnon, K. Frame, J. K. Rowley, B. A. Moffat, K. M. Heeger, I. Blevis, R. S. Storey, John L. Orrell, M. Omori, Joseph A. Formaggio, E. Bonvin, E. D. Hallman, R. Van Berg, W. Locke, A. Roberge, E. T.H. Clifford, J. Boger, T. J. Bowles, C. E. Okada, J. D. Hepburn, S. R. Elliott, David A. Sinclair, G. T. Ewan, T. D. Steiger, K. K. Schaffer, James R. Wilson, T. C. Andersen, A. A. Hamian, E.D. Frank, C. K. Hargrove, D. S. McDonald, X. Dai, V. M. Novikov, R. J. Komar, R. C. Allen, W. Frati, Bhaskar Sur, Mark Neubauer, Richard T. Kouzes, S. S.E. Rosendahl, Hal Evans, M. G. Bowler, M. C. Browne, Ryuta Hazama, R. L. Helmer, M. Bercovitch, S. Majerus, M. Shatkay, C. W. Nally, C. Jillings, C. A. Duba, H. B. Mak, W.F. Davidson, S. D. Biller, J. F. Wilkerson, Reda Tafirout, P. J. Harvey, Darren Grant, P. M. Thornewell, G. Milton, M. A. Howe, J. Manor, Malcolm M. Fowler, Eric B. Norman, H. Seifert, J. R. Leslie, P. Jagam, R. G. Van de Water, N. Starinsky, S. Luoma, and K. T. Lesko

Subjects
Physics, Particle physics, Sudbury Neutrino Observatory, Neutral current, Physics::Instrumentation and Detectors, Solar neutrino, Astrophysics::Cosmology and Extragalactic Astrophysics, Solar neutrino problem, Nuclear physics, Neutrino detector, High Energy Physics::Experiment, Astrophysics::Earth and Planetary Astrophysics, Neutrino, Nuclear Experiment, Neutrino oscillation, Charged current
Abstract

The Sudbury Neutrino Observatory (SNO) is a 1,000 tonne heavy water Cerenkov‐based neutrino detector situated 2,000 meters underground in INCO’s Creighton Mine near Sudbury, Ontario, Canada. For the neutrinos from 8B decay in the Sun SNO observes the Charged Current neutrino reaction sensitive only to electron neutrinos and others (Neutral Current and Elastic Scattering) sensitive to all active neutrino types and thereby can search for direct evidence of neutrino flavor change. Using these reactions and assuming the standard 8B shape, the ve component of the 8B solar flux is φe = 1.76−0.05+0.05(stat.)−0.09+0.09 (syst.) × 106 cm−2s−1 for a kinetic energy threshold of 5 MeV. The non‐ve component is φμτ = 3.41−0.45+0.45(stat.)−0.45+0.48 (syst.) × 106 cm−2s−1, 5.3σ greater than zero, providing strong evidence for solar ve flavor transformation. The total flux measured with the NC reaction is φNC = 5.09−0.43+0.44(stat.)−0.43+0.46 (syst.) × 106 cm−2s−1, consistent with solar models. For charged current events, ...

Published
2002
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86. MOON (Mo Observatory Of Neutrinos) for neutrino studies in [sup 100]Mo by double beta decays and solar-ν capture reactions

Author

Jonathan Engel, Nobuyuki Kudomi, Plamen Krastev, Ryuta Hazama, Masaharu Nomachi, Hiroyasu Ejiri, and R. G. Hamish Robertson

Subjects
Nuclear physics, Physics, Particle physics, Neutrino detector, Solar neutrino, Double beta decay, Measurements of neutrino speed, High Energy Physics::Experiment, Neutrino astronomy, Neutrino, Solar neutrino problem, Neutrino oscillation
Abstract

Neutrino mass is a key issue of current physics, and atmospheric, solar, and accelerator experiments strongly suggest ν oscillations due to non-zero ν-mass differences and flavor mixings. It is of great interest to study ν mass with sensitivity in the 0.05 eV range. Double beta decay may be the only probe presently able to access such small ν masses. It is possible with 100Mo to carry out both spectroscopic studies of double beta decays with the sensitivity of the order of 〈mν〉∼0.03 eV, and realtime exclusive studies of low energy solar ν.

Published
2002
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88. Measurement of CC interactions produced by ${}^8$B solar neutrinos at SNO

Author

H. W. Lee, H. Mes, D. S. McDonald, John Heise, Ilan Levine, J. A. Dunmore, V. M. Novikov, R. U. Haq, Yuen-Dat Chan, J. F. Wilkerson, M. Moorhead, H. S. Ng, J. Cameron, Y. I. Tserkovnyak, Reda Tafirout, A. L. Hallin, E. T.H. Clifford, J. Boger, C. Mifflin, B. T. Cleveland, E. Bonvin, K. McFarlane, Darren Grant, N. Tagg, Christopher C. M. Kyba, C. E. Okada, J. D. Hepburn, S. M. Oser, David A. Sinclair, Hans C. Evans, T. V. Bullard, E. D. Earle, M. C.P. Isaac, R. W. Ollerhead, X. Chen, G. Milton, A. Roberge, N.W. Tanner, J. Lyon, Guthrie Miller, P. Skensved, H. B. Mak, I. Blevis, J. D. Anglin, E. D. Hallman, T. C. Andersen, E. W. Beier, J. H.M. Cowan, R. G. Stokstad, John L. Orrell, Q. R. Ahmad, F. M. Newcomer, C. J. Virtue, E. Saettler, E.D. Frank, Art Mc Donald, W.F. Davidson, Peter Wittich, P. J. Doe, P. Jagam, S. R. Elliott, M. Omori, Herbert H. Chen, G. T. Ewan, K. K. Schaffer, H. Heron, H. Fergani, J. Karn, Y. Dai, R. J. Ford, Klaus Kirch, D. L. Wark, B. A. Moffat, N. Starinsky, R. Heaton, F. A. Duncan, N. McCauley, C. K. Hargrove, J. C. Barton, B. C. Robertson, M. R. Dragowsky, R. K. Taplin, D. F. Cowen, M. G. Boulay, R. L. Hahn, Salvador Gil, F. Dalnoki-Veress, P. T. Trent, A. Goldschmidt, R. S. Storey, G. Doucas, A. S. Hamer, A. D. Marino, A. Knox, N. West, J. R. Leslie, S. D. Biller, R. J. Komar, R. C. Allen, M. W.E. Smith, M. Bercovitch, M. C. Chon, M. O'Neill, M. A. Howe, J. B. Wilhelmy, T. Kutter, R. Meijer Drees, Min Chen, P. J. Harvey, M. Lay, J. Bigu, S. J. Brice, G. McGregor, P. M. Thornewell, W. J. Heintzelman, R. J. Boardman, Richard George Van de Water, G. A. Cox, I. Lawson, T. J. Radcliffe, K. Frame, A. J. Noble, A. W. P. Poon, Malcolm M. Fowler, P. T. Keener, K. T. Lesko, J. J. Simpson, T. J. Bowles, K. M. Heeger, Eric B. Norman, G. Jonkmans, J. M. Wouters, H. Seifert, S. Luoma, A. Schuelke, Minfang Yeh, A. B. McDonald, N. A. Jelley, M. Thorman, A. P. Ferraris, J. X. Wang, V. L. Rusu, K. Cameron, J. G. Hykawy, J. Hewett, Andrew Hime, M. H. Schwendener, W. McLatchie, M. M. Lowry, J. Law, Jochen Klein, J. V. Germani, J. Farine, M. G. Bowler, M. C. Browne, T.H. Burritt, R. A. Black, G. Bühler, A. R. Smith, R. L. Helmer, W. Locke, J. K. Rowley, M. Shatkay, R. Van Berg, C. W. Nally, T. D. Steiger, A. A. Hamian, C. Jillings, Ryuta Hazama, Chris Waltham, S. Majerus, C. A. Duba, R. G. H. Robertson, W. Frati, Bhaskar Sur, Richard T. Kouzes, James R. Wilson, X. Dai, and Mark Neubauer

Subjects
Nuclear physics, Physics, Angular distribution, Solar neutrino, Neutrino oscillation, Charged current
Published
2001
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89. Scintillation efficiency of nuclear recoils in a CaF-2(Eu) crystal for dark matter search

Author

Ryuta Hazama, N. Suzuki, T. Kishimoto, K. Matsuoka, S. Ajimura, H. Miyawaki, H. Hayakawa, and K. Morikubo

Subjects
Physics, Nuclear and High Energy Physics, Scintillation, Quenching (fluorescence), Physics::Instrumentation and Detectors, Doping, Dark matter, Analytical chemistry, FOS: Physical sciences, Neutron radiation, Crystal, Recoil, Electron equivalent, Nuclear Experiment (nucl-ex), Nuclear Experiment, Instrumentation
Abstract

The scintillation efficiency (quenching factor) of fluorine and calcium nuclei recoiling in a CaF-2(Eu) crystal was measured in an energy region relevant to dark matter searches. The recoiling nuclei were obtained via the 19-F(n,n') and 40-Ca(n,n') reactions, where the neutron beam was provided via the d(d,n)3-He reaction. The quenching factor of F and Ca nuclei in the CaF-2(Eu) crystal was found to be 11 ~ 20 %, and 9 ~ 23 % relative to the electron equivalent energy for 53 ~ 192 keV and 25 ~ 91 keV recoil energies, respectively, and the energy dependence was observed. The quenching factor we measured here is a little larger than that of previous studies, which may depend on the Eu doping concentration of the crystal., 19 pages, including 7 encapsulated postscript figures. to be published in NIM-A

Published
2001

91. The Majorana Demonstrator: Progress towards showing the feasibility of a tonne–scale76Ge neutrinoless double–beta decay experiment

Author

Nicole R. Overman, F. T. Avignone, R. L. Varner, L. Mizouni, V. G. Egorov, Kai Vetter, Ryuta Hazama, Yuen-Dat Chan, Alexis G. Schubert, D. C. Radford, J. Esterline, A. S. Barabash, M. F. Kidd, Reynold J. Cooper, V. E. Guiseppe, Richard T. Kouzes, J. H. Merriman, C. D. Christofferson, A. Galindo-Uribarri, Michael G. Marino, M. C. Ronquest, Paul N. Luke, Matthew Busch, K. Gusey, H. Yaver, K. J. Snavely, J. F. Wilkerson, F. M. Fraenkle, A. L. Hallin, M. A. Howe, S. I. Konovalov, Masaharu Nomachi, P. Finnerty, Jonathan D. Leon, P. J. Doe, M. L. Miller, J. I. Collar, Tatsushi Shima, K. Vorren, J. Strain, L. E. Leviner, Vladimir Yumatov, Brian D. LaFerriere, Stanley M. Howard, A. R. Young, Alan Poon, M. Horton, D. Steele, R. D. Martin, A. Knecht, J. A. Detwiler, S. R. Elliott, C.-H. Yu, O.I. Kochetov, K. J. Keeter, J. C. Loach, V. V. Timkin, R. G. H. Robertson, D. C. Combs, J. R. Beene, F. E. Bertrand, S. MacMullin, V. B. Brudanin, M. Boswell, E. Aguayo, Eric W. Hoppe, Paul Barton, E. Yakushev, G. Perumpilly, R. Henning, V. M. Gehman, N. Fields, Werner Tornow, M. P. Green, H. Ejiri, Mark Amman, R. A. Johnson, G. K. Giovanetti, M. Shirchenko, John L. Orrell, Yu. Efremenko, D. G. Phillips, James E. Fast, and Keith Rielage

Subjects
Physics, History, Particle physics, Detector, chemistry.chemical_element, Germanium, Lepton number, Computer Science Applications, Education, Semiconductor detector, Nuclear physics, MAJORANA, chemistry, Double beta decay, Electromagnetic shielding, Neutrino
Abstract

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).

Published
2014
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92. CANDLES

Author

M. Saka, S. Maeda, G. Ito, T. Ueno, M. Tanaka, G. Fujita, A. Yamamoto, H. Kakubata, Ken-Ichi Fushimi, Masaharu Nomachi, J. Takemoto, Koichi Ichimura, Sei Yoshida, A. Kawamura, S. Ajimura, D. Tanaka, Izumi Ogawa, K. Suzuki, W. Wang, Saori Umehara, Tadafumi Kishimoto, T. Harada, Y. Tamagawa, S. Tomita, M. Doihara, W. M. Chan, K. Okada, H. Ohsumi, T. Ishikawa, Ryuta Hazama, N. Nakatani, and K. Matsuoka

Subjects
Physics, MAJORANA, Particle physics, Double beta decay, Underground laboratory, Astrophysics, Neutrino
Abstract

CANDLES is the project to search for neutrino-less double beta decay (0νββ ) of 48 Ca. The observation of 0νββ will prove existence of a massive Majorana neutrino. For the 0νββ measurement, we need a low background condition because of a low decay rate of 0νββ . Now we installed the CANDLES III system at the Kamioka underground laboratory. The CANDLES III system realizes the low background condition by a characteristic structure and data analyses for background rejection. Here we report performances of the CANDLES III system.

Published
2014
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93. PICO-LON Dark Matter Search

Author

Kunio Inoue, Tatsushi Shima, H. Ikeda, Y. Awatani, R. Sugawara, A. Kozlov, Ken-Ichi Fushimi, Ryuta Hazama, H. Ejiri, Reiko Orito, and Shintaro Nakayama

Subjects
Nuclear physics, Physics, History, Low energy, Observatory, DAMA/NaI, Detector, Dark matter, Pulse shape analysis, Scintillator, Computer Science Applications, Education
Abstract

It is an important task to find an annual modulation of WIMPs signal for identifying dark matter signal. To search for annual modulation signal by means of inorganic scintillators, a large mass and a highly radiopure detector is needed. PICO-LON (Planar Inorganic Crystal Observatory for LOw background Neutr(al)inos) is a dark matter search project with multi-array NaI(Tl) scintillators. The test module of PICO-LON whose dimension is 15cm×15cm×0.1cm gives enough performance, energy resolution and low energy threshold, for dark matter search. The highly radiopure NaI(Tl) crystal is indispensable to start a large mass experiment. We have developed highly radiopure NaI(Tl) scintillator. The U and Th chain impurities were precisely measured by meand of pulse shape analysis for NaI(Tl) scintillators. The future plan of KamLAND-PICO dark matter search project is proposed.

Published
2013
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95. Study of polarized 5ΛHe weak decay via (π+,K+) reaction on 6Li

Author

T. Nagae, Ryuta Hazama, K. Manabe, H. Noumi, T. Hasegawa, M. Youn, N. Shinkai, Hiroyasu Ejiri, M. Ishikawa, Kyo Kume, J. Okusu, K. Maeda, T. Inomata, O. Hashimoto, H. Park, T.-A. Shibata, M. Sekimoto, T. Nakano, S. Ajimura, T. Takahashi, H. Bhang, and T. Kishimoto

Subjects
Physics, Energy spectrum, Current (fluid), Atomic physics, Weak interaction
Abstract

We carried out an experiment to study asymmetric weak decays of polarized 5ΛHe produced via (π+,K+) reaction on 6Li. The experiment aims mainly at investigation of the ΛN weak interaction through the hypernuclear weak decays. We introduce the experiment and report current status of analysis.

Published
1995
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96. The MAJORANA experiment: an ultra-low background search for neutrinoless double-beta decay

Author

B. H. LaRoque, K. Vorren, Yuen-Dat Chan, Chao Zhang, G. Perumpilly, A. L. Hallin, F. T. Avignone, R. L. Varner, I. Vanyushin, D. G. Phillips, L. Mizouni, V. M. Gehman, Reyco Henning, D. C. Combs, G. Prior, James E. Fast, A. S. Barabash, Nicole R. Overman, Andrew Hime, S. MacMullin, J. H. Merriman, K. Gusey, Dongming Mei, J. I. Collar, J. F. Wilkerson, Michael G. Marino, C. D. Christofferson, J. Esterline, Alexis G. Schubert, A. Knecht, Keenan Thomas, J. A. Detwiler, M. F. Kidd, Henning O. Back, P. Finnerty, C. Keller, B. A. Wolfe, M. Shirchenko, V. E. Guiseppe, John L. Orrell, M. A. Howe, P. J. Doe, G. K. Giovanetti, M. P. Green, O.I. Kochetov, Reynold J. Cooper, K. J. Snavely, L. E. Leviner, J. C. Loach, M. Horton, M. C. Ronquest, M. L. Miller, H. Ejiri, K. J. Keeter, Keith Rielage, J. Strain, S. R. Elliott, R. A. Johnson, F. E. Bertrand, D. Steele, E. Aguayo, R. D. Martin, V. Efremenko, Jonathan D. Leon, M. Boswell, M. Bergevin, Masaharu Nomachi, S. I. Konovalov, Richard T. Kouzes, Kai Vetter, Eric W. Hoppe, C.-H. Yu, Ryuta Hazama, A. W. P. Poon, R. G. H. Robertson, Brian D. LaFerriere, V. V. Timkin, E. Yakushev, N. Fields, Werner Tornow, V. G. Egorov, Matthew Busch, V. B. Brudanin, D. C. Radford, F. M. Fraenkle, Vladimir Yumatov, Stanley M. Howard, A. R. Young, and Tatsushi Shima

Subjects
Physics, History, Particle physics, Physics - Instrumentation and Detectors, Isotopes of germanium, FOS: Physical sciences, Instrumentation and Detectors (physics.ins-det), Computer Science Applications, Education, MAJORANA, Double beta decay, Invariant mass, Nuclear Experiment (nucl-ex), Neutrino, Nuclear Experiment, Absolute scale, Radioactive decay, Lepton
Abstract

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 determine 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., Comment: Presentation for the Rutherford Centennial Conference on Nuclear Physics

Published
2012
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97. Dark matter sensitivities of the Majorana Demonstrator

Author

Alan Poon, B. H. LaRoque, Masaharu Nomachi, J. A. Detwiler, Eric W. Hoppe, O.I. Kochetov, G. Perumpilly, V. M. Gehman, Brian D. LaFerriere, J. C. Loach, J. Esterline, M. F. Kidd, Vladimir Yumatov, C.-H. Yu, V. B. Brudanin, Kai Vetter, Dongming Mei, V. V. Timkin, Stanley M. Howard, A. R. Young, S. R. Elliott, Ryuta Hazama, Tatsushi Shima, Nicole R. Overman, M. Shirchenko, John L. Orrell, M. Bergevin, M. P. Green, G. Prior, A. S. Barabash, J. F. Wilkerson, Keith Rielage, J. H. Merriman, S. MacMullin, V. G. Egorov, Yuen-Dat Chan, Matthew Busch, Michael G. Marino, K. Gusey, Alexis G. Schubert, J. R. Beene, F. E. Bertrand, C. D. Christofferson, A. L. Hallin, V. E. Guiseppe, P. Finnerty, Chao Zhang, H. Ejiri, M. Boswell, Reynold J. Cooper, J. Strain, M. L. Miller, D. Steele, K. Vorren, J. I. Collar, P. J. Doe, A. Knecht, Keenan Thomas, Yu. Efremenko, R. D. Martin, Henning O. Back, E. Yakushev, M. A. Howe, D. C. Radford, L. E. Leviner, C. Keller, D. G. Phillips, R. G. H. Robertson, K. J. Snavely, N. Fields, Richard T. Kouzes, M. Horton, M. C. Ronquest, L. Mizouni, E. Aguayo, James E. Fast, K. J. Keeter, G. K. Giovanetti, F. M. Fraenkle, R. A. Johnson, S. I. Konovalov, Werner Tornow, I. Vanyushin, F. T. Avignone, R. L. Varner, Reyco Henning, D. C. Combs, and Jonathan D. Leon

Subjects
Physics, History, Particle physics, Physics::Instrumentation and Detectors, Dark matter, Detector, Computer Science Applications, Education, Semiconductor detector, Nuclear physics, MAJORANA, WIMP, Weakly interacting massive particles, Data analysis, High Energy Physics::Experiment, Nuclear Experiment, Event (particle physics)
Abstract

The Majorana Demonstrator is an array of natural and enriched high purity germanium detectors that will search for the neutrinoless double-beta decay of Germanium-76 and perform a search for weakly interacting massive particles with masses below 10 GeV. To reach the background rate goal in the neutrinoless double-beta decay region of interest of 4 counts/keV/t/y, the DEMONSTRATOR will utilize a number of background reduction strategies, including a time-correlated event cut for 68Ge that requires a sub-keV energy threshold. This low energy threshold allows the DEMONSTRATOR to extend its physics reach to include a search for light WIMPs. We will discuss the detector systems and data analysis techniques required to achieve sub-keV thresholds as well as present the projected dark matter sensitivities of the Majorana Demonstrator.

Published
2012
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98. Study of48Ca Double Beta Decay by CANDLES

Author

Ken-Ichi Fushimi, Izumi Ogawa, K. Seki, Masaharu Nomachi, H. Kakubata, K. Okada, Yoichi Tamagawa, K. Matsuoka, G. Ito, N Fujiwara, M. Saka, Saori Umehara, H. Ohsumi, T Jinno, Ryuta Hazama, M. Miyashita, S. Yoshida, K. Yasuda, K Takubo, and Tadafumi Kishimoto

Subjects
Physics, History, Particle physics, Astrophysics::High Energy Astrophysical Phenomena, High Energy Physics::Phenomenology, Astrophysics::Cosmology and Extragalactic Astrophysics, Scintillator, Computer Science Applications, Education, Nuclear physics, MAJORANA, Double beta decay, High Energy Physics::Experiment, Neutrino, Nuclear Experiment
Abstract

CANDLES is a project to search for neutrinoless double beta decay of 48Ca using CaF2 scintillators. The observation of neutrinoless double beta decay would confirm the existence of massive Majorana neutrinos. Herein the expected performances and current status of the CANDLES system are described.

Published
2011
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99. Dark matter search by means of segmented scintillator (PICO-LON)

Author

K Harada, K. Imagawa, Saori Umehara, Y. Kameda, K Yasuda, Tatsushi Shima, Ken-Ichi Fushimi, Shintaro Nakayama, Ryuta Hazama, and Hiroyasu Ejiri

Subjects
Crystal, Physics, History, Optics, Wide area, business.industry, Dark matter, Detector, Astrophysics, Scintillator, business, Computer Science Applications, Education
Abstract

Thin and wide area inorganic crystal was applied to search for WIMPs dark matter. A multilayer NaI(Tl) detector has great advantages for WIMPs dark matter search. The performance of the thin (5mm thickness) and wide area (18cm×18cm) was developed. The performance tests were performed and the results were good for dark matter search.

Published
2010
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100. MOON for double-beta decays and neutrino nuclear responses

Author

K Harada, Y. Kameda, Tatsushi Shima, Ken-Ichi Fushimi, Hiroyasu Ejiri, Ryuta Hazama, K. Imagawa, K Yasuda, and Shintaro Nakayama

Subjects
Physics, Nuclear physics, Crystal, History, Wide area, Beta (plasma physics), Double beta decay, Resolution (electron density), Electron, Neutrino, Computer Science Applications, Education
Abstract

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

Published
2010
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