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Sample records for borexino solar neutrino

  1. Solar neutrino physics with Borexino I

    CERN Document Server

    Ludhova, L; Benziger, J; Bick, D; Bonfini, G; Bravo, D; Avanzini, M Buizza; Caccianiga, B; Cadonati, L; Calaprice, F; Carraro, C; Cavalcante, P; Chavarria, A; D'Angelo, D; Davini, S; Derbin, A; Etenko, A; Fomenko, K; Franco, D; Galbiati, C; Gazzana, S; Ghiano, C; Giammarchi, M; Goeger-Nef, M; Goretti, A; Grandi, L; Guardincerri, E; Hardy, S; Ianni, Aldo; Ianni, Andrea; Kayunov, A; Kobychev, V; Korablev, D; Korga, G; Koshio, Y; Kryn, D; Laubenstein, M; Lewke, T; Litvinovich, E; Loer, B; Lombardi, F; Lombardi, P; Machulin, I; Manecki, S; Maneschg, W; Manuzio, G; Meindl, Q; Meroni, E; Miramonti, L; Misiaszek, M; Montanari, D; Mosteiro, P; Muratova, V; Oberauer, L; Obolenksy, M; Ortica, F; Otis, K; Pallavicini, M; Papp, L; Perasso, L; Perasso, S; Pocar, A; Raghavan, R S; Ranucci, G; Razeto, A; Re, A; Romani, P A; Sabelnikov, A; Saldanha, R; Salvo, C; Schoenert, S; Simgen, H; Skorokhvatov, M; Smirnov, O; Sotnikov, A; Sukhotin, S; Suvorov, Y; Tartaglia, R; Testera, G; Vignaud, D; Vogelaar, R B; Von Feilitzsch, F; Winter, J; Wojcik, M; Wright, A; Wurm, M; Xu, J; Zaimidoroga, O; Zavatarelli, S; Zuzel, G

    2012-01-01

    Borexino is a large-volume liquid scintillator detector installed in the underground halls of the Laboratori Nazionali del Gran Sasso in Italy. After several years of construction, data taking started in May 2007. The Borexino phase I ended after about three years of data taking. Borexino provided the first real time measurement of the $^{7}$Be solar neutrino interaction rate with accuracy better than 5% and confirmed the absence of its day-night asymmetry with 1.4% precision. This latter Borexino results alone rejects the LOW region of solar neutrino oscillation parameters at more than 8.5 $\\sigma$ C.L. Combined with the other solar neutrino data, Borexino measurements isolate the MSW-LMA solution of neutrino oscillations without assuming CPT invariance in the neutrino sector. Borexino has also directly observed solar neutrinos in the 1.0-1.5 MeV energy range, leading to the first direct evidence of the $pep$ solar neutrino signal and the strongest constraint of the CNO solar neutrino flux up to date. Borexi...

  2. New results of the Borexino experiment: pp solar neutrino detection

    Science.gov (United States)

    Davini, S.; Bellini, G.; Benziger, J.; Bick, D.; Bonfini, G.; Bravo, D.; Caccianiga, B.; Calaprice, F.; Caminata, A.; Cavalcante, P.; Chepurnov, A.; D'Angelo, D.; Derbin, A.; Etenko, A.; Fomenko, K.; Franco, D.; Galbiati, C.; Ghiano, C.; Goretti, A.; Gromov, M.; Ianni, Aldo; Ianni, Andrea; Kobychev, V.; Korablev, D.; Korga, G.; Kryn, D.; Laubenstein, M.; Lewke, T.; Litvinovich, E.; Lombardi, F.; Lombardi, P.; Ludhova, L.; Lukyanchenko, G.; Machulin, I.; Manecki, S.; Maneschg, W.; Marcocci, S.; Meroni, E.; Misiaszek, M.; Mosteiro, P.; Muratova, V.; Oberauer, L.; Obolensky, M.; Ortica, F.; Otis, K.; Pallavicini, M.; Papp, L.; Pocar, A.; Ranucci, G.; Razeto, A.; Re, A.; Romani, A.; Rossi, N.; Salvo, C.; Schönert, S.; Simgen, H.; Skorokhvatov, M.; Smirnov, O.; Sotnikov, A.; Sukhotin, S.; Suvorov, Y.; Tartaglia, R.; Testera, G.; Vignaud, D.; Vogelaar, R. B.; Winter, J.; Wojcik, M.; Wurm, M.; Zaimidoroga, O.; Zavatarelli, S.; Zuzel, G.

    2016-07-01

    The Borexino experiment is an ultra-pure liquid scintillator detector, running at Laboratori Nazionali del Gran Sasso (Italy). Borexino has completed the real time spectroscopy of the solar neutrinos generated in the proton-proton chain in the core of the Sun. This article reviews the Borexino experiment and the first direct measurment of pp solar neutrinos.

  3. The Borexino Solar Neutrino Experiment And Its Scintillator Containment Vessel

    CERN Document Server

    Cadonati, L

    2001-01-01

    Thirty years ago, the first solar neutrino detector proved fusion reactions power the Sun. However, the total rate detected in this and all subsequent solar neutrino experiments is consistently two to three times lower than predicted by the Standard Solar Model. Current experiments seek to explain this “solar neutrino puzzle” through non-standard particle properties, like neutrino mass and flavor mixing, within the context of the MSW theory. The detection of the monoenergetic 7Be solar neutrino is the missing clue for the solution of the solar neutrino problem; this constitutes the main physics goal of Borexino, a real- time, high-statistics solar neutrino detector located under the Gran Sasso mountain, in Italy. In the first part of this thesis, I present a Monte Carlo study of the expected performance of Borexino, with simulations of the neutrino rate, the external y background and the α/β/γ activity in the scintillator. The Standard Solar Model predicts a so...

  4. The impact of Borexino on the solar and neutrino physics

    Science.gov (United States)

    Bellini, Gianpaolo

    2016-07-01

    The Borexino detector is characterized by a very low background level due to an unprecedented radio-purity, which allows to study the entire spectrum of solar neutrinos from very low energies (∼150 keV). The solar neutrino rates from pp, 7Be, pep, 8B (with a threshold down to 3 MeV) and a stringent limit of the CNO cycle rate have been already measured. In addition evidences of a null day/night asymmetry and of the solar neutrino flux seasonal variation have been reached. The contribution provided until now by Borexino in understanding the neutrino oscillation phenomenon concerns the first evidence of the oscillation in vacuum and the determination of the νe survival probability in vacuum: these results validate the paradigmatic MSW model in the vacuum regime. The Borexino results are also in good agreement with the Standard Solar Model predictions, but the metallicity puzzle is still unsolved. In addition the pp flux measured by Borexino shows a good agreement with the Solar luminosity. Evidence of geo-neutrinos has been also obtained at the level of 5.9σ C.L. Borexino is still taking data in order to: upgrade the precision of the solar neutrino rates already measured, increase the sensitivity to the neutrino flux from the CNO cycle and hopefully measure it (very challenging), and test the existence of very short base-line neutrino oscillations.

  5. A scintillator purification system for the Borexino solar neutrino detector

    Science.gov (United States)

    Benziger, J.; Cadonati, L.; Calaprice, F.; Chen, M.; Corsi, A.; Dalnoki-Veress, F.; Fernholz, R.; Ford, R.; Galbiati, C.; Goretti, A.; Harding, E.; Ianni, Aldo; Ianni, Andrea; Kidner, S.; Leung, M.; Loeser, F.; McCarty, K.; McKinsey, D.; Nelson, A.; Pocar, A.; Salvo, C.; Schimizzi, D.; Shutt, T.; Sonnenschein, A.

    2008-03-01

    Purification of the 278 tons of liquid scintillator and 889 tons of buffer shielding for the Borexino solar neutrino detector is performed with a system that combines distillation, water extraction, gas stripping, and filtration. This paper describes the principles of operation, design, and construction of that purification system, and reviews the requirements and methods to achieve system cleanliness and leak-tightness.

  6. The Recent Results of the Solar Neutrino Measurement in Borexino

    CERN Document Server

    Koshio, Yusuke

    2011-01-01

    The recent released results of 153.62 ton year exposure of solar neutrino data in Borexino are here discussed. Borexino is a multi-purpose detector with large volume liquid scintillator, located in the underground halls of the Laboratori Nazionali del Gran Sasso in Italy. The experiment is running since 2007. The first realtime 7Be solar neutrino measurement has been released in 2008. Thanks to the precise detector calibration in 2009, the 7Be flux measurement has been reached with an accuracy better than 5%. The result related to the day/night effect in the $^7$Be energy region is also discussed. These results validate the MSW-LMA model for solar neutrino oscillation.

  7. Internal Radioactive Source Calibration Of The Borexino Solar Neutrino Experiment

    CERN Document Server

    Back, H O

    2004-01-01

    A measurement of solar neutrinos below 1 MeV of energy will further our knowledge of the neutrino's mass and mixing properties and will provide a probe to possible physics beyond the standard model of particle physics, as well as advance our understanding of energy production in the Sun. Borexino is a liquid scintillator detector that will measure the neutrino energy spectrum to the lowest energy threshold to date. It has been designed to measure the flux of the mono-energetic neutrinos produced by electron capture on 7Be in the Sun's core, which will produce a Compton-like edge in the energy spectrum. Because of the low count rate, Borexino requires extremely low backgrounds, and a good understanding of the backgrounds that do exist. Although the purification techniques used for the scintillator lowered the radioactive contaminates to levels never before achieved, cuts must still be made to the data. At Virginia Tech, we have developed an internal source calibration program that will be able to give us a tho...

  8. Science and Technology of BOREXINO A Real Time Detector for Low Energy Solar Neutrinos

    CERN Document Server

    Alimonti, G; Back, H O; Balata, M; Beau, T; Bellini, G; Benziger, J B; Bonetti, S; Brigatti, A; Caccianiga, B; Cadonati, L; Calaprice, F P; Cecchet, G; Chen, M; De Bari, A; De Haas, E; De Kerret, H; Donghi, O; Deutsch, M; Elisei, F; Etenko, A; Von Feilitzsch, F; Fernholz, R C; Ford, R; Freudiger, B; Garagiola, A; Galbiati, C; Gatti, F; Gazzana, S; Giammarchi, M G; Giugni, D; Golubchikov, A; Goretti, A; Grieb, C; Hagner, C; Hagner, T; Hampel, W; Harding, E; Hartmann, F; Von Hentig, R; Hess, H; Heusser, G; Ianni, A; Inzani, P; Kidner, S H; Kiko, J; Kirsten, T; Korga, G; Korschinek, G; Kryn, Didier; Lagomarsino, V; La Marche, P; Laubenstein, M; Löser, F; Lombardi, P; Magni, S; Malvezzi, S; Maneira, J; Manno, I; Manuzio, G; Masetti, F; Mazzucato, U; Meroni, E; Musico, P; Neder, H; Neff, M; Nisi, S; Oberauer, L; Obolensky, M; Pallavicini, M; Papp, L; Perasso, L; Pocar, A; Raghavan, R; Ranucci, G; Rau, W; Razeto, A; Resconi, E; Riedel, T; Sabelnikov, A A; Saggese, P; Salvo, C; Scardaoni, R; Schönert, S; Schuhbeck, K; Seidel, H; Shutt, T A; Simgen, H; Sonnenschein, A H; Smirnov, O Yu; Sotnikov, A; Skorokhvatov, M; Sukhotin, S V; Tartaglia, R; Testera, G; Vitale, S; Vogelaar, R; Wójcik, M; Zaimidoroga, O A; Zakharov, Yu I

    2002-01-01

    BOREXINO, a real-time device for low energy neutrino spectroscopy is nearing completion of construction in the underground laboratories at Gran Sasso, Italy (LNGS). The experiment's goal is the direct measurement of the flux of 7Be solar neutrinos of all flavors via neutrino-electron scattering in an ultra-pure scintillation liquid. Seeded by a series of innovations which were brought to fruition by large scale operation of a 4-ton test detector at LNGS, a new technology has been developed for BOREXINO. It enables sub-MeV solar neutrino spectroscopy for the first time. This paper describes the design of BOREXINO, the various facilities essential to its operation, its spectroscopic and background suppression capabilities and a prognosis of the impact of its results towards resolving the solar neutrino problem. BOREXINO will also address several other frontier questions in particle physics astrophysics and geophysics.

  9. Borexino A real time liquid scintillator detector for low energy solar neutrino study

    CERN Document Server

    Miramonti, L

    2002-01-01

    Borexino is a large unsegmented calorimeter featuring 300 tons of liquid scintillator, contained in a 8.5 meter nylon vessel, viewed by 2200 PMTs. The main goal of Borexino is the study, in real time, of low energy solar neutrinos, and in particular, the monoenergetic neutrinos coming from $^7Be$, which is one of the missing links on the solar neutrino problem. The achievement of high radiopurity level, in the order of $10^{-16} g/g$ of U/Th equivalent, necessary to the detection of the low energy component of the solar neutrino flux, was proved in the Borexino prototype: the Counting Test Facility. The detector is located underground in the Laboratori Nazionali del Gran Sasso in the center of Italy at 3500 meter water equivalent depth. In this paper the science and technology of Borexino are reviewed and its main capabilities are presented.

  10. First real–time detection of solar pp neutrinos by Borexino

    Directory of Open Access Journals (Sweden)

    Pallavicini M.

    2016-01-01

    Full Text Available Solar neutrinos have been pivotal to the discovery of neutrino flavour oscillations and are a unique tool to probe the reactions that keep the Sun shine. Although most of solar neutrino components have been directly measured, the neutrinos emitted by the keystone pp reaction, in which two protons fuse to make a deuteron, have so far eluded direct detection. The Borexino experiment, an ultra–pure liquid scintillator detector running at the Laboratori Nazionali del Gran Sasso in Italy, has now filled the gap, providing the first direct real time measurement of pp neutrinos and of the solar neutrino luminosity.

  11. First real-time detection of solar pp neutrinos by Borexino

    Science.gov (United States)

    Pallavicini, M.; Bellini, G.; Benziger, J.; Bick, D.; Bonfini, G.; Bravo, D.; Caccianiga, B.; Calaprice, F.; Caminata, A.; Cavalcante, P.; Chavarria, A.; Chepurnov, A.; D'Angelo, D.; Davini, S.; Derbin, A.; Empl, A.; Etenko, A.; Fomenko, K.; Franco, D.; Gabriele, F.; Galbiati, C.; Gazzana, S.; Ghiano, C.; Giammarchi, M.; Göger-Neff, M.; Goretti, A.; Gromov, M.; Hagner, C.; Hungerford, E.; Ianni, Al.; Ianni, An.; Kayser, M.; Kobychev, V.; Korablëv, D.; Korga, G.; Kryn, D.; Laubenstein, M.; Lehnert, B.; Lewke, T.; Litvinovich, E.; Lombardi, F.; Lombardi, P.; Ludhova, L.; Lukyanchenko, G.; Machulin, I.; Manecki, S.; Maneschg, W.; Marcocci, S.; Meindl, Q.; Meroni, E.; Meyer, M.; Miramonti, L.; Misiaszek, M.; Montuschi, M.; Mosteiro, P.; Muratova, V.; Oberauer, L.; Obolensky, M.; Ortica, F.; Otis, K.; Papp, L.; Perasso, L.; Pocar, A.; Ranucci, G.; Razeto, A.; Re, A.; Romani, A.; Rossi, N.; Saldanha, R.; Salvo, C.; Schönert, S.; Simgen, H.; Skorokhvatov, M.; Smirnov, O.; Sotnikov, A.; Sukhotin, S.; Suvorov, Y.; Tartaglia, R.; Testera, G.; Vignaud, D.; Vogelaar, R. B.; von Feilitzsch, F.; Wang, H.; Winter, J.; Wojcik, M.; Wurm, M.; Zaimidoroga, O.; Zavatarelli, S.; Zuber, K.; Zuzel, G.

    2016-07-01

    Solar neutrinos have been pivotal to the discovery of neutrino flavour oscillations and are a unique tool to probe the reactions that keep the Sun shine. Although most of solar neutrino components have been directly measured, the neutrinos emitted by the keystone pp reaction, in which two protons fuse to make a deuteron, have so far eluded direct detection. The Borexino experiment, an ultra-pure liquid scintillator detector running at the Laboratori Nazionali del Gran Sasso in Italy, has now filled the gap, providing the first direct real time measurement of pp neutrinos and of the solar neutrino luminosity.

  12. Final results of Borexino Phase-I on low energy solar neutrino spectroscopy

    CERN Document Server

    Bellini, G; Bick, D; Bonfini, G; Bravo, D; Avanzini, M B; Caccianiga, B; Cadonati, L; Calaprice, F; Cavalcante, P; Chavarria, A; Chepurnov, A; D'Angelo, D; Davini, S; Derbin, A; Empl, A; Etenko, A; Fomenko, K; Franco, D; Galbiati, C; Gazzana, S; Ghiano, C; Giammarchi, M; Goeger-Neff, M; Goretti, A; Grandi, L; Hagner, C; Hungerford, E; Ianni, Aldo; Ianni, Andrea; Kobychev, V; Korablev, D; Korga, G; Kryn, D; Laubenstein, M; Lewke, T; Litvinovich, E; Loer, B; Lombardi, F; Lombardi, P; Ludhova, L; Lukyanchenko, G; Machulin, I; Manecki, S; Maneschg, W; Manuzio, G; Meindl, Q; Meroni, E; Miramonti, L; Misiaszek, M; Mosteiro, P; Muratova, V; Oberauer, L; Obolensky, M; Ortica, F; Otis, K; Pallavicini, M; Papp, L; Pena-Garay, C; Perasso, L; Perasso, S; Pocar, A; Ranucci, G; Razeto, A; Re, A; Romani, A; Rossi, N; Saldanha, R; Salvo, C; Schoenert, S; Simgen, H; Skorokhvatov, M; Smirnov, O; Sotnikov, A; Sukhotin, S; Suvorov, Y; Tartaglia, R; Testera, G; Vignaud, D; Vogelaar, R B; von Feilitzsch, F; Winter, J; Wojcik, M; Wright, A; Wurm, M; Xu, J; Zaimidoroga, O; Zavatarelli, S; Zuzel, G

    2013-01-01

    Borexino has been running since May 2007 at the LNGS with the primary goal of detecting solar neutrinos. The detector, a large, unsegmented liquid scintillator calorimeter characterized by unprecedented low levels of intrinsic radioactivity, is optimized for the study of the lower energy part of the spectrum. During the Phase-I (2007-2010) Borexino first detected and then precisely measured the flux of the 7Be solar neutrinos, ruled out any significant day-night asymmetry of their interaction rate, made the first direct observation of the pep neutrinos, and set the tightest upper limit on the flux of CNO neutrinos. In this paper we discuss the signal signature and provide a comprehensive description of the backgrounds, quantify their event rates, describe the methods for their identification, selection or subtraction, and describe data analysis. Key features are an extensive in situ calibration program using radioactive sources, the detailed modeling of the detector response, the ability to define an innermos...

  13. The status of the study of solar CNO neutrinos in the Borexino experiment

    Energy Technology Data Exchange (ETDEWEB)

    Lukyanchenko, G. A., E-mail: egorxe@yandex.ru [National Research Center Kurchatov Institute (Russian Federation); Collaboration: Borexino Collaboration

    2015-12-15

    Although less than 1% of solar energy is generated in the CNO cycle, it plays a critical role in astrophysics, since this cycle is the primary source of energy in certain more massive stars and at later stages of evolution of solar-type stars. Electron neutrinos are produced in the CNO cycle reactions. These neutrinos may be detected by terrestrial neutrino detectors. Various solar models with different abundances of elements heavier than helium predict different CNO neutrino fluxes. A direct measurement of the CNO neutrino flux could help distinguish between these models and solve several other astrophysical problems. No CNO neutrinos have been detected directly thus far, and the best upper limit on their flux was set in the Borexino experiment. The work on reducing the background in the region of energies of CNO neutrinos (up to 1.74 MeV) and developing novel data analysis methods is presently under way. These efforts may help detect the CNO neutrino flux in the Borexino experiment at the level predicted by solar models.

  14. Direct measurement of the 7Be solar neutrino flux with 192 days of borexino data.

    Science.gov (United States)

    Arpesella, C; Back, H O; Balata, M; Bellini, G; Benziger, J; Bonetti, S; Brigatti, A; Caccianiga, B; Cadonati, L; Calaprice, F; Carraro, C; Cecchet, G; Chavarria, A; Chen, M; Dalnoki-Veress, F; D'Angelo, D; de Bari, A; de Bellefon, A; de Kerret, H; Derbin, A; Deutsch, M; di Credico, A; di Pietro, G; Eisenstein, R; Elisei, F; Etenko, A; Fernholz, R; Fomenko, K; Ford, R; Franco, D; Freudiger, B; Galbiati, C; Gatti, F; Gazzana, S; Giammarchi, M; Giugni, D; Goeger-Neff, M; Goldbrunner, T; Goretti, A; Grieb, C; Hagner, C; Hampel, W; Harding, E; Hardy, S; Hartman, F X; Hertrich, T; Heusser, G; Ianni, Aldo; Ianni, Andrea; Joyce, M; Kiko, J; Kirsten, T; Kobychev, V; Korga, G; Korschinek, G; Kryn, D; Lagomarsino, V; Lamarche, P; Laubenstein, M; Lendvai, C; Leung, M; Lewke, T; Litvinovich, E; Loer, B; Lombardi, P; Ludhova, L; Machulin, I; Malvezzi, S; Manecki, S; Maneira, J; Maneschg, W; Manno, I; Manuzio, D; Manuzio, G; Martemianov, A; Masetti, F; Mazzucato, U; McCarty, K; McKinsey, D; Meindl, Q; Meroni, E; Miramonti, L; Misiaszek, M; Montanari, D; Monzani, M E; Muratova, V; Musico, P; Neder, H; Nelson, A; Niedermeier, L; Oberauer, L; Obolensky, M; Orsini, M; Ortica, F; Pallavicini, M; Papp, L; Parmeggiano, S; Perasso, L; Pocar, A; Raghavan, R S; Ranucci, G; Rau, W; Razeto, A; Resconi, E; Risso, P; Romani, A; Rountree, D; Sabelnikov, A; Saldanha, R; Salvo, C; Schimizzi, D; Schönert, S; Shutt, T; Simgen, H; Skorokhvatov, M; Smirnov, O; Sonnenschein, A; Sotnikov, A; Sukhotin, S; Suvorov, Y; Tartaglia, R; Testera, G; Vignaud, D; Vitale, S; Vogelaar, R B; von Feilitzsch, F; von Hentig, R; von Hentig, T; Wojcik, M; Wurm, M; Zaimidoroga, O; Zavatarelli, S; Zuzel, G

    2008-08-29

    We report the direct measurement of the 7Be solar neutrino signal rate performed with the Borexino detector at the Laboratori Nazionali del Gran Sasso. The interaction rate of the 0.862 MeV 7Be neutrinos is 49+/-3stat+/-4syst counts/(day.100 ton). The hypothesis of no oscillation for 7Be solar neutrinos is inconsistent with our measurement at the 4sigma C.L. Our result is the first direct measurement of the survival probability for solar nu(e) in the transition region between matter-enhanced and vacuum-driven oscillations. The measurement improves the experimental determination of the flux of 7Be, pp, and CNO solar nu(e), and the limit on the effective neutrino magnetic moment using solar neutrinos.

  15. First evidence of pep solar neutrinos by direct detection in Borexino.

    Science.gov (United States)

    Bellini, G; Benziger, J; Bick, D; Bonetti, S; Bonfini, G; Bravo, D; Buizza Avanzini, M; Caccianiga, B; Cadonati, L; Calaprice, F; Carraro, C; Cavalcante, P; Chavarria, A; Chepurnov, A; D'Angelo, D; Davini, S; Derbin, A; Etenko, A; Fomenko, K; Franco, D; Galbiati, C; Gazzana, S; Ghiano, C; Giammarchi, M; Goeger-Neff, M; Goretti, A; Grandi, L; Guardincerri, E; Hardy, S; Ianni, Aldo; Ianni, Andrea; Korablev, D; Korga, G; Koshio, Y; Kryn, D; Laubenstein, M; Lewke, T; Litvinovich, E; Loer, B; Lombardi, F; Lombardi, P; Ludhova, L; Machulin, I; Manecki, S; Maneschg, W; Manuzio, G; Meindl, Q; Meroni, E; Miramonti, L; Misiaszek, M; Montanari, D; Mosteiro, P; Muratova, V; Oberauer, L; Obolensky, M; Ortica, F; Otis, K; Pallavicini, M; Papp, L; Perasso, L; Perasso, S; Pocar, A; Quirk, J; Raghavan, R S; Ranucci, G; Razeto, A; Re, A; Romani, A; Sabelnikov, A; Saldanha, R; Salvo, C; Schönert, S; Simgen, H; Skorokhvatov, M; Smirnov, O; Sotnikov, A; Sukhotin, S; Suvorov, Y; Tartaglia, R; Testera, G; Vignaud, D; Vogelaar, R B; von Feilitzsch, F; Winter, J; Wojcik, M; Wright, A; Wurm, M; Xu, J; Zaimidoroga, O; Zavatarelli, S; Zuzel, G

    2012-02-03

    We observed, for the first time, solar neutrinos in the 1.0-1.5 MeV energy range. We determined the rate of pep solar neutrino interactions in Borexino to be 3.1±0.6{stat}±0.3{syst}  counts/(day·100  ton). Assuming the pep neutrino flux predicted by the standard solar model, we obtained a constraint on the CNO solar neutrino interaction rate of solar neutrino signal is disfavored at 99.97% C.L., while the absence of the pep signal is disfavored at 98% C.L. The necessary sensitivity was achieved by adopting data analysis techniques for the rejection of cosmogenic {11}C, the dominant background in the 1-2 MeV region. Assuming the Mikheyev-Smirnov-Wolfenstein large mixing angle solution to solar neutrino oscillations, these values correspond to solar neutrino fluxes of (1.6±0.3)×10{8}  cm{-2} s^{-1} and solar models. These results represent the first direct evidence of the pep neutrino signal and the strongest constraint of the CNO solar neutrino flux to date.

  16. New results on solar neutrino fluxes from 192 days of Borexino data

    CERN Document Server

    Arpesella, C; Balata, M; Bellini, G; Benziger, J; Bonetti, S; Brigatti, A; Caccianiga, B; Cadonati, L; Calaprice, F; Carraro, C; Cecchet, G; Chavarria, A; Chen, M; Dalnoki-Veress, F; D'Angelo, D; De Bari, A; De Bellefon, A; De Kerret, H; Derbin, A; Deutsch, M; di Credico, A; Di Pietro, G; Eisenstein, R; Elisei, F; Etenko, A; Fernholz, R; Fomenko, K; Ford, R; Franco, D; Freudiger, B; Galbiati, C; Gatti, F; Gazzana, S; Giammarchi, M; Giugni, D; Goeger-Neff, M; Goldbrunner, T; Goretti, A; Grieb, C; Hagner, C; Hampel, W; Harding, E; Hardy, S; Hartman, F X; Hertrich, T; Heusser, G; Ianni, Aldo; Ianni, Andrea; Joyce, M; Kiko, J; Kirsten, T; Kobychev, V; Korga, G; Korschinek, G; Kryn, D; Lagomarsino, V; Lamarche, P; Laubenstein, M; Lendvai, C; Leung, M; Lewke, T; Litvinovich, E; Loer, B; Lombardi, P; Ludhova, L; Machulin, I; Malvezzi, S; Manecki, S; Maneira, J; Maneschg, W; Manno, I; Manuzio, D; Manuzio, G; Martemianov, A; Masetti, F; Mazzucato, U; McCarty, K; McKinsey, D; Meindl, Q; Meroni, E; Miramonti, L; Misiaszek, M; Montanari, D; Monzani, M E; Muratova, V; Musico, P; Neder, H; Nelson, A; Niedermeier, L; Oberauer, L; Obolensky, M; Orsini, M; Ortica, F; Pallavicini, M; Papp, L; Parmeggiano, S; Perasso, L; Pocar, A; Raghavan, R S; Ranucci, G; Rau, W; Razeto, A; Resconi, E; Risso, P; Romani, A; Rountree, D; Sabelnikov, A; Saldanha, R; Salvo, C; Schimizzi, D; Schönert, S; Shutt, T; Simgen, H; Skorokhvatov, M; Smirnov, O; Sonnenschein, A; Sotnikov, A; Sukhotin, S; Suvorov, Y; Tartaglia, R; Testera, G; Vignaud, D; Vitale, S; Vogelaar, R B; Von Feilitzsch, F; Von Hentig, R; von Hentig, T; Wójcik, M; Wurm, M; Zaimidoroga, O; Zavatarelli, S; Zuzel, G

    2008-01-01

    We report the direct measurement of the ^7Be solar neutrino signal rate performed with the Borexino detector at the Laboratori Nazionali del Gran Sasso. The interaction rate of the 0.862 MeV ^7Be neutrinos is 49+-3(stat)+-4(syst) counts/(day * 100ton). The hypothesis of no oscillation for ^7Be solar neutrinos is inconsistent with our measurement at the 4sigma level. Our result is the first direct measurement of the survival probability for solar nu_e in the transition region between matter-enhanced and vacuum-driven oscillations. The measurement improves the experimental determination of the flux of ^7Be, pp, and CNO solar nu_e, and the limit on the magnetic moment of neutrinos.

  17. First evidence of pep solar neutrinos by direct detection in Borexino

    CERN Document Server

    ,

    2011-01-01

    We observed, for the first time, solar neutrinos in the 1.0-1.5 MeV energy range. We measured the rate of pep solar neutrino interactions in Borexino to be [3.1+-0.6(stat)+-0.3(syst)] counts/(day x 100 ton) and provided a constraint on the CNO solar neutrino interaction rate of <7.9 counts/(day x 100 ton) (95% C.L.). The absence of the solar neutrino signal is disfavored at 99.97% C.L., while the absence of the pep signal is disfavored at 98% C.L. This unprecedented sensitivity was achieved by adopting novel data analysis techniques for the rejection of cosmogenic 11C, the dominant background in the 1-2 MeV region. Assuming the MSW-LMA solution to solar neutrino oscillations, these values correspond to solar neutrino fluxes of [1.6+-0.3]x10^8 cm^-2s-1 and 7.7x10^8 cm^-2s-1 (95% C.L.), respectively, in agreement with the Standard Solar Model. These results represent the first measurement of the pep neutrino flux and the strongest constraint of the CNO solar neutrino flux to date.

  18. Low-energy solar neutrino spectroscopy with Borexino. Towards the detection of the solar pep and CNO neutrino flux

    Energy Technology Data Exchange (ETDEWEB)

    Maneschg, Werner

    2011-05-11

    Borexino is a large-volume organic liquid scintillator detector of unprecedented high radiopurity which has been designed for low-energy neutrino spectroscopy in real time. Besides the main objective of the experiment, the measurement of the solar {sup 7}Be neutrino flux, Borexino also aims at detecting solar neutrinos from the pep fusion process and from the CNO cycle. The detectability of these neutrinos is strictly connected to a successful rejection of all relevant background components. The identification and reduction of these background signals is the central subject of this dissertation. In the first part, contaminants induced by cosmic-ray muons and muon showers were analyzed. The dominant background is the cosmogenic radioisotope {sup 11}C. Its rate is {proportional_to}10 times higher than the expected combined pep and CNO neutrino rate in the preferred energy window of observation at [0.8,1.3] MeV. Since {sup 11}C is mostly produced under the release of a free neutron, {sup 11}C can be tagged with a threefold coincidence (TFC) consisting of the muon signal, the neutron capture and the subsequent {sup 11}C decay. By optimizing the TFC method and other rejection techniques, a {sup 11}C rejection efficiency of 80% was achieved. This led to a neutrino-to-background ratio of 1:1.7, whereby 61% of statistics is lost. The second part of the work concerns the study of the external background. Especially long-range 2.6 MeV gamma rays from {sup 208}Tl decays in the outer detector parts can reach the scintillator in the innermost region of the detector. For the determination of the resultant spectral shape, a custom-made {proportional_to}5 MBq {sup 228}Th source was produced and an external calibration was carried out for the first time. The obtained calibration data and the achieved {sup 11}C rejection efficiency will allow for the direct detection of solar pep and possibly also CNO neutrinos with Borexino. (orig.)

  19. Precision measurement of the (7)Be solar neutrino interaction rate in Borexino.

    Science.gov (United States)

    Bellini, G; Benziger, J; Bick, D; Bonetti, S; Bonfini, G; Buizza Avanzini, M; Caccianiga, B; Cadonati, L; Calaprice, F; Carraro, C; Cavalcante, P; Chavarria, A; D'Angelo, D; Davini, S; Derbin, A; Etenko, A; Fomenko, K; Franco, D; Galbiati, C; Gazzana, S; Ghiano, C; Giammarchi, M; Goeger-Neff, M; Goretti, A; Grandi, L; Guardincerri, E; Hardy, S; Ianni, Aldo; Ianni, Andrea; Kobychev, V; Korablev, D; Korga, G; Koshio, Y; Kryn, D; Laubenstein, M; Lewke, T; Litvinovich, E; Loer, B; Lombardi, F; Lombardi, P; Ludhova, L; Machulin, I; Manecki, S; Maneschg, W; Manuzio, G; Meindl, Q; Meroni, E; Miramonti, L; Misiaszek, M; Montanari, D; Mosteiro, P; Muratova, V; Oberauer, L; Obolensky, M; Ortica, F; Pallavicini, M; Papp, L; Peña-Garay, C; Perasso, L; Perasso, S; Pocar, A; Raghavan, R S; Ranucci, G; Razeto, A; Re, A; Romani, A; Sabelnikov, A; Saldanha, R; Salvo, C; Schönert, S; Simgen, H; Skorokhvatov, M; Smirnov, O; Sotnikov, A; Sukhotin, S; Suvorov, Y; Tartaglia, R; Testera, G; Vignaud, D; Vogelaar, R B; von Feilitzsch, F; Winter, J; Wojcik, M; Wright, A; Wurm, M; Xu, J; Zaimidoroga, O; Zavatarelli, S; Zuzel, G

    2011-09-30

    The rate of neutrino-electron elastic scattering interactions from 862 keV (7)Be solar neutrinos in Borexino is determined to be 46.0±1.5(stat)(-1.6)(+1.5)(syst) counts/(day·100  ton). This corresponds to a ν(e)-equivalent (7)Be solar neutrino flux of (3.10±0.15)×10(9)  cm(-2) s(-1) and, under the assumption of ν(e) transition to other active neutrino flavours, yields an electron neutrino survival probability of 0.51±0.07 at 862 keV. The no flavor change hypothesis is ruled out at 5.0 σ. A global solar neutrino analysis with free fluxes determines Φ(pp)=6.06(-0.06)(+0.02)×10(10)  cm(-2) s(-1) and Φ(CNO)neutrino oscillation model is experimentally tested at low energy.

  20. Vacuum oscillations and variations of solar neutrino rates in SuperKamiokande and Borexino

    CERN Document Server

    Faid, B; Lisi, E; Montanino, D

    1999-01-01

    The vacuum oscillation solution to the solar neutrino problem predicts characteristics variations of the observable neutrinos rates, as a result of the L/E_nu dependence of the nu_e survival probability (L and E_nu being the neutrino pathlength and energy, respectively). The E_nu-dependence can be studied through distortions of the recoil electron spectrum in the SuperKamiokande experiment. The L-dependence can be investigated through a Fourier analysis of the signal in the SuperKamiokande and Borexino experiments. We discuss in detail the interplay among such observable variations of the signal, and show how they can help to test and constrain the vacuum oscillation solution(s). The analysis includes the 374-day SuperKamiokande data.

  1. Global analysis of Solar neutrino oscillation evidence including SNO and implications for Borexino

    CERN Document Server

    Aliani, P; Picariello, M; Torrente-Lujan, E

    2002-01-01

    An updated analysis of all available neutrino oscillation evidence in Solar experiments including the latest $SNO$ data is presented. Predictions for total rates and day-night asymmetry in Borexino are calculated. Our analysis features the use of exhaustive computation of the neutrino oscillation probabilities and the use of an improved statistical $\\chi^2$ minimization. In the framework of two neutrino oscillations we conclude that the best fit to the data is obtained in the LMA region with parameters $(\\Delta m^2, \\tan^2\\theta) = (5.2 \\times 10^{-5} \\eV^2, 0.47)$, ($\\chi^2_{min}/n=0.82$, $n=38$ degrees of freedom). Although less favored, solutions in the LOW and VAC regions are still possible with a reasonable statistical significance. The best possible solution in the SMA region gets as maximum a statistical significance as low as $\\sim 3%$. We study the implications of these results for the prospects of Borexino and the possibility of discriminating between the different solutions. The expected normalized...

  2. Highly sensitive measurements of radioactive noble gas nuclides in the BOREXINO solar neutrino experiment.

    Science.gov (United States)

    Simgen, H; Heusser, G; Zuzel, G

    2004-01-01

    Low background miniaturized proportional counters as developed for the GALLEX solar neutrino experiment can be applied to the detection of radioactive noble gas nuclides at very low activities. We have developed an apparatus that allows the activity of trace amounts of isotopes of the four noble gases Ar, Kr, Xe and Rn to be measured. The technique includes contamination-free chromatographic purification of raw gas samples and subsequent low-level counting. Minimum detectable activities of 100 microBq and below have been attained. The developed techniques can be used to determine the 222Rn and 85Kr concentration in nitrogen for the solar neutrino experiment BOREXINO. By applying efficient techniques to concentrate noble gases from nitrogen, minimum detectable activity concentrations below 1 microBq/m3 of nitrogen (STP) have been reached for both nuclides.

  3. Absence of day-night asymmetry of 862 keV Be-7 solar neutrino rate in Borexino and MSW oscillation parameters

    CERN Document Server

    ,

    2011-01-01

    We report on a search for the day-night asymmetry of the Be-7 solar neutrino rate measured by Borexino at the Laboratori Nazionali del Gran Sasso (LNGS), Italy. The measured value, Adn=0.001 +- 0.012 (stat) +- 0.007 (syst), shows the absence of a significant asymmetry. This result alone rejects the so-called LOW solution at more than 8.5 sigma. Combined with the other solar neutrino data, it isolates the Large Mixing Angle (LMA) -- MSW solution at DeltaChi2 > 190 without relying on the assumption of CPT symmetry in the neutrino sector. We also show that including the day-night asymmetry, data from Borexino alone restricts the MSW neutrino oscillations to the LMA solution at 90% confidence level.

  4. Short distance neutrino oscillations with Borexino

    Directory of Open Access Journals (Sweden)

    Caminata A.

    2016-01-01

    Full Text Available The Borexino detector has convincingly shown its outstanding performances in the low energy, sub-MeV regime through its unprecedented accomplishments in the solar and geo-neutrinos detection. These performances make it the ideal tool to accomplish a state-of-the-art experiment able to test unambiguously the long-standing issue of the existence of a sterile neutrino, as suggested by the several anomalous results accumulated over the past two decades, i.e. the outputs of the LSND and Miniboone experiments, the results of the source calibration of the two Gallium solar neutrino experiments, and the recently hinted reactor anomaly. The SOX project will exploit two sources, based on Chromium and Cerium, respectively, which deployed under the experiment, in a location foreseen on purpose at the time of the construction of the detector, will emit two intense beams of neutrinos (Cr and anti-neutrinos (Ce. Interacting in the active volume of the liquid scintillator, each beam would create an unmistakable spatial wave pattern in case of oscillation of the νe (or ν̅e into the sterile state: such a pattern would be the smoking gun proving the existence of the new sterile member of the neutrino family. Otherwise, its absence will allow setting a very stringent limit on its existence.

  5. Short distance neutrino oscillations with Borexino

    Science.gov (United States)

    Caminata, A.; Agostini, M.; Altenmüller, K.; Appel, S.; Bellini, G.; Benziger, J.; Berton, N.; Bick, D.; Bonfini, G.; Bravo, D.; Caccianiga, B.; Calaprice, F.; Cavalcante, P.; Chepurnov, A.; Cribier, M.; D'Angelo, D.; Davini, S.; Derbin, A.; di Noto, L.; Durero, M.; Empl, A.; Etenko, A.; Farinon, S.; Fischer, V.; Fomenko, K.; Franco, D.; Gabriele, F.; Gaffiot, J.; Galbiati, C.; Ghiano, C.; Giammarchi, M.; Göger-Neff, M.; Goretti, A.; Gromov, M.; Hagner, C.; Houdy, Th.; Hungerford, E.; Ianni, Aldo; Ianni, Andrea; Jonquères, N.; Kaiser, M.; Kobychev, V.; Korablev, D.; Korga, G.; Kryn, D.; Lachenmaier, T.; Lasserre, T.; Laubenstein, M.; Lehnert, B.; Link, J.; Litvinovich, E.; Lombardi, F.; Lombardi, P.; Ludhova, L.; Lukyanchenko, G.; Machulin, I.; Maneschg, W.; Marcocci, S.; Maricic, J.; Mention, G.; Meroni, E.; Meyer, M.; Miramonti, L.; Misiaszek, M.; Montuschi, M.; Muratova, V.; Musenich, R.; Neumair, B.; Oberauer, L.; Obolensky, M.; Ortica, F.; Pallavicini, M.; Papp, L.; Perasso, L.; Pocar, A.; Ranucci, G.; Razeto, A.; Re, A.; Romani, A.; Rossi, N.; Schönert, S.; Scola, L.; Simgen, H.; Skorokhvatov, M.; Smirnov, O.; Sotnikov, A.; Sukhotin, S.; Suvorov, Y.; Tartaglia, R.; Testera, G.; Veyssière, C.; Vivier, M.; Vogelaar, R. B.; von Feilitzsch, F.; Wang, H.; Winter, J.; Wojcik, M.; Wurm, M.; Zaimidoroga, O.; Zavatarelli, S.; Zuber, K.; Zuzel, G.

    2016-07-01

    The Borexino detector has convincingly shown its outstanding performances in the low energy, sub-MeV regime through its unprecedented accomplishments in the solar and geo-neutrinos detection. These performances make it the ideal tool to accomplish a state-of-the-art experiment able to test unambiguously the long-standing issue of the existence of a sterile neutrino, as suggested by the several anomalous results accumulated over the past two decades, i.e. the outputs of the LSND and Miniboone experiments, the results of the source calibration of the two Gallium solar neutrino experiments, and the recently hinted reactor anomaly. The SOX project will exploit two sources, based on Chromium and Cerium, respectively, which deployed under the experiment, in a location foreseen on purpose at the time of the construction of the detector, will emit two intense beams of neutrinos (Cr) and anti-neutrinos (Ce). Interacting in the active volume of the liquid scintillator, each beam would create an unmistakable spatial wave pattern in case of oscillation of the νe (or ν̅e) into the sterile state: such a pattern would be the smoking gun proving the existence of the new sterile member of the neutrino family. Otherwise, its absence will allow setting a very stringent limit on its existence.

  6. Measurement of neutrinos released in nuclear reactors through the Borexino experiment; Mesure des neutrinos de reacteurs nucleaires dans l'experience Borexino

    Energy Technology Data Exchange (ETDEWEB)

    Dadoun, O

    2003-06-01

    The main goal of the Borexino experiment is to measure in real time the solar neutrino flux from the beryllium (Be{sup 7}) line at 862 keV. Beyond this pioneer low energy neutrino detection, Borexino will be able to measure solar neutrinos above the MeV, (B{sup 8} neutrinos and pep neutrinos), nuclear reactor neutrinos (with an average energy of 3 MeV) and the supernova neutrinos (their spectrum goes up to some ten MeV). In this work I mainly focus on the study of the nuclear reactors neutrinos. This field has recently been enriched by the results of the KamLAND experiment, which have greatly improved the determination of the neutrino oscillation parameters. In order to measure these events which are above the MeV, the Borexino collaboration entrusted the PCC group at College de France, with the tasks of developing a fast digit system running at 400 MHz: the FADC cards. The PCC group designed the FADC cards and completed them at the beginning of 2002. The first cards which were introduced in the main electronic acquisition unit allowed us to control their functioning and that of the acquisition software. FADC cards were also installed in the Borexino prototype, CTF. The data are analysed in order to determine a limit to the expected background noise of Borexino in measuring the nuclear reactor neutrinos. (author)

  7. Radon diffusion through polymer membranes used in the solar neutrino experiment Borexino

    CERN Document Server

    Wójcik, M; Zuzel, G; Heusser, G

    2000-01-01

    We have measured the radon diffusion, solubility and permeability coefficients of various foils being of interest for the Borexino experiment. The applied methods and instrumentation are described and the mathematical model for diffusion of Rn, including its decay, is outlined. A very strong influence of water on the Rn diffusion through nylon foils was found. The rather low Rn permeability for dry nylon foil (mean value is equal to 3.35x10 sup - sup 1 sup 2 cm sup 2 /s) increases by more than two orders of magnitude if the foil is immersed in water. No significant influence compared to dry nylon has been observed if the foil was surrounded by pseudocumene.

  8. Neutrino measurements from the Sun and Earth: Results from Borexino

    Energy Technology Data Exchange (ETDEWEB)

    Bellini, G.; Caccianiga, B.; D’Angelo, D.; Giammarchi, M.; Lombardi, P.; Ludhova, L.; Meroni, E.; Miramonti, L.; Ranucci, G., E-mail: gioacchino.ranucci@mi.infn.it; Re, A. [Dipartimento di Fisica, Universitá degli Studi e INFN, 20133 Milano (Italy); Benziger, J. [Chemical Engineering Department, Princeton University, Princeton, New Jersey 08544 (United States); Bick, D.; Hagner, C.; Meyer, M. [Institut für Experimentalphysik, Universität Hamburg, 22761 Hamburg (Germany); Bonfini, G.; Cavalcante, P.; Gabriele, F.; Gazzana, S.; Ianni, Aldo; Laubenstein, M. [INFN Laboratori Nazionali del Gran Sasso, 67100 Assergi (Italy); and others

    2015-07-15

    Important neutrino results came recently from Borexino, a massive, calorimetric liquid scintillator detector installed at the underground Gran Sasso Laboratory. With its unprecedented radiopurity levels achieved in the core of the detection medium, it is the only experiment in operation able to study in real time solar neutrino interactions in the challenging sub-MeV energy region. The recently achieved breakthrough observation of the fundamental pp flux, the precise measurement of the {sup 7}Be solar neutrino flux, and the results concerning the pep, {sup 8}B and CNO fluxes, together with their physics implications, are described in this work. Moreover, the detector has also provided a clean detection of terrestrial neutrinos, from which they emerge as a new probe of the interior of the Earth.

  9. Ar and Kr concentrations in nitrogen as a measure of the 39Ar and 85Kr activities in connection with the solar neutrino experiment BOREXINO.

    Science.gov (United States)

    Zuzel, G; Simgen, H; Heusser, G

    2004-01-01

    Among other radionuclides, 39Ar and 85Kr are potential background sources in the solar neutrino detector BOREXINO. The expected low event rate requires that the nitrogen used in the experiment needs to have lower concentrations than 0.5 microBq/m3 for 39Ar and 0.2 microBq/m3 for 85Kr, corresponding to volume concentrations in N2 of 0.4 x 10(-6)m3/m3 for Ar and 0.2 x 10(-12)m3/m3 for Kr. Applying gas mass spectrometry and special care in the sampling technique we succeeded in finding the required purity. In addition, we studied the possibility to purify nitrogen from Kr by the adsorption method.

  10. SOX: search for short baseline neutrino oscillations with Borexino

    Science.gov (United States)

    Vivier, M.; Agostini, M.; Altenmüller, K.; Appel, S.; Bellini, G.; Benziger, J.; Berton, N.; Bick, D.; Bonfini, G.; Bravo, D.; Caccianiga, B.; Calaprice, F.; Caminata, A.; Cavalcante, P.; Chepurnov, A.; Choi, K.; Cribier, M.; D'Angelo, D.; Davini, S.; Derbin, A.; Di Noto, L.; Drachnev, I.; Durero, M.; Etenko, A.; Farinon, S.; Fischer, V.; Fomenko, K.; Franco, D.; Gabriele, F.; Gaffliot, J.; Galbiati, C.; Ghiano, C.; Giammarchi, M.; Goeger-Neff, M.; Goretti, A.; Gromov, M.; Hagner, C.; Houdy, T.; Hungerford, E.; Ianni, Aldo; Ianni, Andrea; Jonquàres, N.; Jedrzejczak, K.; Kaiser, M.; Kobychev, V.; Korablev, D.; Korga, G.; Kornoukhov, V.; Kryn, D.; Lachenmaier, T.; Lasserre, T.; Laubenstein, M.; Lehnert, B.; Link, J.; Litvinovich, E.; Lombardi, F.; Lombardi, P.; Ludhova, L.; Lukyanchenko, G.; Machulin, I.; Manecki, S.; Maneschg, W.; Marcocci, S.; Maricic, J.; Mention, G.; Meroni, E.; Meyer, M.; Miramonti, L.; Misiaszek, M.; Montuschi, M.; Mosteiro, P.; Muratova, V.; Musenich, R.; Neumair, B.; Oberauer, L.; Obolensky, M.; Ortica, F.; Pallavicini, M.; Papp, L.; Perasso, L.; Pocar, A.; Ranucci, G.; Razeto, A.; Re, A.; Romani, A.; Roncin, R.; Rossi, N.; Schönert, S.; Scola, L.; Semenov, D.; Skorokhvatov, M.; Smirnov, O.; Sotnikov, A.; Sukhotin, S.; Suvorov, Y.; Tartaglia, R.; Testera, G.; Thurn, J.; Toropova, M.; Veyssiére, C.; Unzhakov, E.; Vogelaar, R. B.; von Feilitzsch, F.; Wang, H.; Weinz, S.; Winter, J.; Wojcik, M.; Wurm, M.; Yokley, Z.; Zaimidoroga, O.; Zavatarelli, S.; Zuber, K.; Zuzel, G.; Borexino Collaboration

    2016-05-01

    The Borexino detector has convincingly shown its outstanding performances in the low energy regime through its accomplishments in the observation and study of the solar and geo neutrinos. It is then an ideal tool to perform a state of the art source-based experiment for testing the longstanding hypothesis of a fourth sterile neutrino with ~ eV2 mass, as suggested by several anomalies accumulated over the past three decades in source, reactor, and accelerator-based experiments. The SOX project aims at successively deploying two intense radioactive sources, made of Cerium (antineutrino) and Chromium (neutrino), respectively, in a dedicated pit located beneath the detector. The existence of such an ~ eV2 sterile neutrino would then show up as an unambiguous spatial and energy distortion in the count rate of neutrinos interacting within the active detector volume. This article reports on the latest developments about the first phase of the SOX experiment, namely CeSOX, and gives a realistic projection of CeSOX sensitivity to light sterile neutrinos in a simple (3+1) model.

  11. Probing neutrino nature at Borexino detector with chromium neutrino source

    CERN Document Server

    Sobków, W

    2016-01-01

    In this paper, we indicate a possibility of utilizing the intense chromium source ($\\sim 370 PBq$) in probing the neutrino nature in low energy neutrino experiments with the ultra-low threshold and background real-time Borexino detector located near the source ($\\sim 8 m$). We analyze the elastic scattering of electron neutrinos (Dirac or Majorana, respectively) on the unpolarized electrons in the relativistic neutrino limit. We assume that the incoming neutrino beam is the superposition of left-right chiral states. Left chiral neutrinos may be detected by the standard $V A$ and non-standard scalar $S_L$, tensor $T_L$ interactions, while right chiral ones partake only in the exotic $V + A$ and $S_R, T_R$ interactions. Our model-independent study is carried out for the flavour (current) neutrino eigenstates. We compute the expected event number for the standard $V-A$ interaction of the left chiral neutrinos using the current experimental values of standard couplings and in the case of left-right chiral superpo...

  12. Probing neutrino nature at Borexino detector with chromium neutrino source

    Energy Technology Data Exchange (ETDEWEB)

    Sobkow, W.; Blaut, A. [University of Wroclaw, Institute of Theoretical Physics, Wroclaw (Poland)

    2016-10-15

    In this paper, we indicate a possibility of utilizing the intense chromium source (∝370 PBq) in probing the neutrino nature in low energy neutrino experiments with the ultra-low threshold and background real-time Borexino detector located near the source (∝8 m). We analyse the elastic scattering of electron neutrinos (Dirac or Majorana, respectively) on the unpolarised electrons in the relativistic neutrino limit. We assume that the incoming neutrino beam is the superposition of left-right chiral states produced by the chromium source. Left chiral neutrinos may be detected by the standard V - A and non-standard scalar S{sub L}, pseudoscalar P{sub L}, tensor T{sub L} interactions, while right chiral ones partake only in the exotic V + A and S{sub R}, P{sub R}, T{sub R} interactions. Our model-independent study is carried out for the flavour (current) neutrino eigenstates. We compute the expected event number for the standard V - A interaction of the left chiral neutrinos using the current experimental values of standard couplings and in the case of left-right chiral superposition. We show that the significant decrement in the event number due to the interference terms between the standard and exotic interactions for the Majorana neutrinos may appear. We also demonstrate how the presence of the exotic couplings affects the energy spectrum of outgoing electrons, both for the Dirac and Majorana cases. The 90 % C.L. sensitivity contours in the planes of corresponding exotic couplings are found. The presence of interferences in the Majorana case gives the stronger constraints than for the Dirac neutrinos, even if the neutrino source is placed outside the detector. (orig.)

  13. Study of very low energy neutrinos from the Sun and from the Earth with the Borexino detector.

    CERN Document Server

    CERN. Geneva

    2011-01-01

    Borexino is a liquid scintillator unsegmented detector, running at the Gran Sasso underground Laboratories (LNGS). Thanks to its unprecedented low level of radioactive contamination, Borexino currently is the only experiment able to perform a real time measurement of solar neutrino interactions below few MeV. In solar neutrinos Borexino measured the neutrino flux from 7Be (862 keV) with total uncertainty smaller than 5%, the flux from 8B with a lower threshold down to 3 MeV, the day/night asymmetry of the 7Be neutrino flux with a total experimental uncertainty of 1%. These measurements introduce strong constraints also on the solar neutrino flux from the pp and CNO reactions. The impact of these Borexino results are extremely relevant both in solar physics, in connection with the understanding of Sun-like stars, and in neutrino physics. In particular, the precision measurement of the 7Be solar neutrino flux allows a real time investigation of neutrino oscillations below few MeV and provides a unique opportuni...

  14. Measurement of CNGS muon neutrino speed with Borexino

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez Sanchez, P., E-mail: spokeperson-borex@lngs.infn.it [CERN, Geneva (Switzerland); Barzaghi, R. [DIIAR-Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano (Italy); Bellini, G. [Dipartimento di Fisica, Universita degli Studi e INFN, Milano 20133 (Italy); Benziger, J. [Chemical Engineering Department, Princeton University, Princeton, NJ 08544 (United States); Betti, B.; Biagi, L. [DIIAR-Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano (Italy); Bick, D. [University of Hamburg, Hamburg (Germany); Bonfini, G. [INFN-Laboratori Nazionali del Gran Sasso, Assergi 67010 (Italy); Bravo, D. [Physics Department, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061 (United States); Buizza Avanzini, M.; Caccianiga, B. [Dipartimento di Fisica, Universita degli Studi e INFN, Milano 20133 (Italy); Cadonati, L. [Physics Department, University of Massachusetts, Amherst, MA 01003 (United States); Carraro, C. [Dipartimento di Fisica, Universita e INFN, Genova 16146 (Italy); Cavalcante, P. [INFN-Laboratori Nazionali del Gran Sasso, Assergi 67010 (Italy); Cerretto, G. [Optics Division, INRIM (Istituto Nazionale di Ricerca Metrologica), Torino (Italy); Chavarria, A. [Physics Department, Princeton University, Princeton, NJ 08544 (United States); D' Angelo, D. [Dipartimento di Fisica, Universita degli Studi e INFN, Milano 20133 (Italy); Davini, S. [Dipartimento di Fisica, Universita e INFN, Genova 16146 (Italy); Physics Department, Houston University, Houston, TX 77204-5005 (United States); De Gaetani, C. [DIIAR-Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano (Italy); Derbin, A. [St. Petersburg Nuclear Physics Institute, Gatchina 188350 (Russian Federation); and others

    2012-10-02

    We have measured the speed of muon neutrinos with the Borexino detector using short-bunch CNGS beams. The final result for the difference in time-of-flight between an Left-Pointing-Angle-Bracket E Right-Pointing-Angle-Bracket =17 GeV muon neutrino and a particle moving at the speed of light in vacuum is {delta}t=0.8{+-}0.7{sub stat}{+-}2.9{sub sys} ns, well consistent with zero.

  15. Borexino's search for low-energy neutrino and antineutrino signals correlated with gamma-ray bursts

    Science.gov (United States)

    Agostini, M.; Altenmüller, K.; Appel, S.; Atroshchenko, V.; Bellini, G.; Benziger, J.; Bick, D.; Bonfini, G.; Bravo, D.; Caccianiga, B.; Calaprice, F.; Caminata, A.; Carlini, M.; Cavalcante, P.; Chepurnov, A.; Choi, K.; D'Angelo, D.; Davini, S.; de Kerret, H.; Derbin, A.; Di Noto, L.; Drachnev, I.; Etenko, A.; Fomenko, K.; Franco, D.; Gabriele, F.; Galbiati, C.; Ghiano, C.; Giammarchi, M.; Goeger-Neff, M.; Goretti, A.; Gromov, M.; Hagner, C.; Hungerford, E.; Ianni, Aldo; Ianni, Andrea; Jany, A.; Jedrzejczak, K.; Jeschke, D.; Kobychev, V.; Korablev, D.; Korga, G.; Kryn, D.; Laubenstein, M.; Lehnert, B.; Litvinovich, E.; Lombardi, F.; Lombardi, P.; Ludhova, L.; Lukyanchenko, G.; Machulin, I.; Manecki, S.; Maneschg, W.; Manuzio, G.; Marcocci, S.; Meroni, E.; Meyer, M.; Miramonti, L.; Misiaszek, M.; Montuschi, M.; Mosteiro, P.; Muratova, V.; Neumair, B.; Oberauer, L.; Obolensky, M.; Ortica, F.; Pallavicini, M.; Papp, L.; Pocar, A.; Ranucci, G.; Razeto, A.; Re, A.; Romani, A.; Roncin, R.; Rossi, N.; Schönert, S.; Semenov, D.; Skorokhvatov, M.; Smirnov, O.; Sotnikov, A.; Sukhotin, S.; Suvorov, Y.; Tartaglia, R.; Testera, G.; Thurn, J.; Toropova, M.; Unzhakov, E.; Vishneva, A.; Vogelaar, R. B.; von Feilitzsch, F.; Wang, H.; Weinz, S.; Winter, J.; Wojcik, M.; Wurm, M.; Yokley, Z.; Zaimidoroga, O.; Zavatarelli, S.; Zuber, K.; Zuzel, G.

    2017-01-01

    A search for neutrino and antineutrino events correlated with 2350 gamma-ray bursts (GRBs) is performed with Borexino data collected between December 2007 and November 2015. No statistically significant excess over background is observed. We look for electron antineutrinos (νbare) that inverse beta decay on protons with energies from 1.8 MeV to 15 MeV and set the best limit on the neutrino fluence from GRBs below 8 MeV. The signals from neutrinos and antineutrinos from GRBs that scatter on electrons are also searched for, a detection channel made possible by the particularly radio-pure scintillator of Borexino. We obtain currently the best limits on the neutrino fluence of all flavors and species below 7 MeV. Finally, time correlations between GRBs and bursts of events are investigated. Our analysis combines two semi-independent data acquisition systems for the first time: the primary Borexino readout optimized for solar neutrino physics up to a few MeV, and a fast waveform digitizer system tuned for events above 1 MeV.

  16. Experimental evidence of electron neutrino oscillations and validation of MSW-LMA model with Borexino

    Science.gov (United States)

    Avanzini, M. Buizza

    2011-04-01

    We report the real time measurements of 7Be and 8B solar neutrino fluxes performed with the Borexino experiment at the Laboratori Nazionali del Gran Sasso. The achievement of these measurements was possible thanks to the excellent levels of the radiopurity reached. The measurement of the 7Be in real time is the first direct measurements of the survival probability for solar electron neutrinos in the vacuum region. For 8B we reached a threshold energy of 3MeV which is the lowest achieved so far in real time. For the first time, the same apparatus can measure two different oscillation regions (vacuum-driven and matter-enhanced) predicted by the MSW-LMA model. Borexino also quotes the ratio between the survival probabilities, corresponding to 1.93 ± 0.75, and validates the presence of the transition region between the two oscillation regimes, according to the MSW-LMA solution.In addition, a preliminary result on the Day-Night Asymmetry (ADN) for the 7Be neutrino flux is presented and corresponds to 0.007 ± 0.073. This measurement makes Borexino able to give once more an independent confirmation of the MSW-LMA solution.

  17. Studies of scintillator optical properties, electronics simulation and data analysis for the BOREXINO neutrino experiment

    Energy Technology Data Exchange (ETDEWEB)

    Lewke, Timo

    2013-10-18

    Borexino is a state-of-the-art low-energy neutrino detector. Many results, like the first real-time measurement of {sup 7}Be neutrinos and the detection of pep neutrinos, could be reported. However, still some parts of the solar neutrino spectrum remain unseen. With a better detector understanding and monitoring these unexploited regions could be investigated. The results achieved in course of the present thesis account for accomplishing these improvements. First, the ionization quenching for electrons in liquid scintillators is investigated using a specially designed and build experiment. This effect is especially interesting for low-energy events and, therefore, has a direct influence on the possibility to detect CNO and pp neutrinos. With a coincidence circuit and the properties of Compton scattering the quenching is analysed. Further, the so-called Birks factor kB is measured for the scintillator used in the running Borexino experiment. As the Birks factor is also an important input parameter to simulations of the future large scale neutrino experiment LENA, the Birks factor of LENA's most probable scintillator is determined as well. Second, as muons are responsible for a large amount of background, an excellent working muon veto is essential. During this thesis, it was achieved to monitor the muon tagging stability and efficiency for a long period of time. Further, to verify the muon track reconstruction Monte Carlo simulations are needed. For the Inner Detector of Borexino the simulation is fully operable. In course of this thesis the complete electronics system of the Outer Detector is included into the simulation tool. In this way, a functioning simulation mimicking real physical events is generated. In addition, the output of the simulation can now be accessed and evaluated by the normal data handling system of Borexino. A comparison to real data and, therefore, validating the muon track reconstruction is now possible. Last, to check the neutron

  18. Experimental data on solar neutrinos

    Energy Technology Data Exchange (ETDEWEB)

    Ludhova, Livia [INFN, Milano (Italy)

    2016-04-15

    Neutrino physics continues to be a very active research field, full of opened fundamental questions reaching even beyond the Standard Model of elementary particles and towards a possible new physics. Solar neutrinos have played a fundamental historical role in the discovery of the phenomenon of neutrino oscillations and thus non-zero neutrino mass. Even today, the study of solar neutrinos provides an important insight both into the neutrino as well as into the stellar and solar physics. In this section we give an overview of the most important solar-neutrino measurements from the historical ones up to the most recent ones. We cover the results from the experiments using radio-chemic (Homestake, SAGE, GNO, GALLEX), water Cherenkov (Kamiokande, Super-Kamiokande, SNO), and the liquid-scintillator (Borexino, KamLAND) detection techniques. (orig.)

  19. Combined analysis of KamLAND and Borexino neutrino signals from Th and U decays in the Earth's interior

    CERN Document Server

    Fogli, G L; Palazzo, A; Rotunno, A M

    2010-01-01

    The KamLAND and Borexino experiments have detected electron antineutrinos produced in the decay chains of natural thorium and uranium (Th and U geoneutrinos). We analyze the energy spectra of current geoneutrino data in combination with solar and long-baseline reactor neutrino data, with marginalized three-neutrino oscillation parameters. We consider the case with unconstrained Th and U event rates in KamLAND and Borexino, as well as cases with fewer degrees of freedom, as obtained by successively assuming for both experiments a common Th/U ratio, a common scaling of Th+U event rates, and a chondritic Th/U value. In combination, KamLAND and Borexino can reject the null hypothesis (no geoneutrino signal) at 5 sigma. Interesting bounds or indications emerge on the Th+U geoneutrino rates and on the Th/U ratio, in broad agreement with typical Earth model expectations. Conversely, the results disfavor the hypothesis of a georeactor in the Earth's core, if its power exceeds a few TW. The interplay of KamLAND and Bo...

  20. Spectroscopy of geo-neutrinos from 2056 days of Borexino data

    CERN Document Server

    Agostini, M; Bellini, G; Benziger, J; Bick, D; Bonfini, G; Bravo, D; Caccianiga, B; Calaprice, F; Caminata, A; Cavalcante, P; Chepurnov, A; Choi, K; DAngelo, D; Davini, S; Derbin, A; Di Noto, L; Drachnev, I; Empl, A; Etenko, A; Fiorentini, G; Fomenko, K; Franco, D; Gabriele, F; Galbiati, C; Ghiano, C; Giammarchi, M; Goger-Neff, M; Goretti, A; Gromov, M; Hagner, C; Hungerford, E; Ianni, Aldo; Ianni, Andrea; Jedrzejczak, K; Kaiser, M; Kobychev, V; Korablev, D; Korga, G; Kryn, D; Laubenstein, M; Lehnert, B; Litvinovich, E; Lombardi, F; Lombardi, P; Ludhova, L; Lukyanchenko, G; Machulin, I; Manecki, S; Maneschg, W; Mantovani, F; Marcocci, S; Meroni, E; Meyer, M; Miramonti, L; Misiaszek, M; Montuschi, M; Mosteiro, P; Muratova, V; Oberauer, L; Obolensky, M; Ortica, F; Otis, K; Pagani, L; Pallavicini, M; Papp, L; Perasso, L; Perasso, S; Pocar, A; Ranucci, G; Razeto, A; Re, A; Ricci, B; Romani, A; Roncin, R; Rossi, N; Schoenert, S; Semenov, D; Simgen, H; Skorokhavatov, M; Smirnov, O; Sotnikov, A; Sukhotin, S; Suvorov, Y; Tartaglia, R; Testera, G; Thurn, J; Toropova, M; Unzhakov, E; Vogelaar, R B; von Feilitzsch, F; Wang, H; Weinz, S; Winter, J; Woicik, M; Wurm, M; Yokley, Z; Zaimidoroga, O; Zavatarelli, S; Zuber, K; Zuzel, G

    2015-01-01

    We report an improved geo-neutrino measurement with Borexino from 2056 days of data taking. The present exposure is $(5.5\\pm0.3)\\times10^{31}$ proton$\\times$yr. Assuming a chondritic Th/U mass ratio of 3.9, we obtain $23.7 ^{+6.5}_{-5.7} (stat) ^{+0.9}_{-0.6} (sys)$ geo-neutrino events. The null observation of geo-neutrinos with Borexino alone has a probability of $3.6 \\times 10^{-9}$ (5.9$\\sigma$). A geo-neutrino signal from the mantle is obtained at 98\\% C.L. The radiogenic heat production for U and Th from the present best-fit result is restricted to the range 23-36 TW, taking into account the uncertainty on the distribution of heat producing elements inside the Earth.

  1. Measurement of neutrino flux from the primary proton-proton fusion process in the Sun with Borexino detector

    Science.gov (United States)

    Smirnov, O. Yu.; Agostini, M.; Appel, S.; Bellini, G.; Benziger, J.; Bick, D.; Bonfini, G.; Bravo, D.; Caccianiga, B.; Calaprice, F.; Caminata, A.; Cavalcante, P.; Chepurnov, A.; Choi, K.; D'Angelo, D.; Davini, S.; Derbin, A.; Di Noto, L.; Drachnev, I.; Empl, A.; Etenko, A.; Fomenko, K.; Franco, D.; Gabriele, F.; Galbiati, C.; Ghiano, C.; Giammarchi, M.; Goeger-Neff, M.; Goretti, A.; Gromov, M.; Hagner, C.; Hungerford, E.; Ianni, Aldo; Ianni, Andrea; Jedrzejczak, K.; Kaiser, M.; Kobychev, V.; Korablev, D.; Korga, G.; Kryn, D.; Laubenstein, M.; Lehnert, B.; Litvinovich, E.; Lombardi, F.; Lombardi, P.; Ludhova, L.; Lukyanchenko, G.; Machulin, I.; Manecki, S.; Maneschg, W.; Marcocci, S.; Meroni, E.; Meyer, M.; Miramonti, L.; Misiaszek, M.; Mosteiro, P.; Muratova, V.; Neumair, B.; Oberauer, L.; Obolensky, M.; Ortica, F.; Otis, K.; Pagani, L.; Pallavicini, M.; Papp, L.; Perasso, L.; Pocar, A.; Ranucci, G.; Razeto, A.; Re, A.; Romani, A.; Roncin, R.; Rossi, N.; Schönert, S.; Semenov, D.; Simgen, H.; Skorokhvatov, M.; Sotnikov, A.; Sukhotin, S.; Suvorov, Y.; Tartaglia, R.; Testera, G.; Thurn, J.; Toropova, M.; Unzhakov, E.; Vogelaar, R. B.; von Feilitzsch, F.; Wang, H.; Weinz, S.; Winter, J.; Wojcik, M.; Wurm, M.; Yokley, Z.; Zaimidoroga, O.; Zavatarelli, S.; Zuber, K.; Zuzel, G.

    2016-11-01

    Neutrino produced in a chain of nuclear reactions in the Sun starting from the fusion of two protons, for the first time has been detected in a real-time detector in spectrometric mode. The unique properties of the Borexino detector provided an oppurtunity to disentangle pp-neutrino spectrum from the background components. A comparison of the total neutrino flux from the Sun with Solar luminosity in photons provides a test of the stability of the Sun on the 105 years time scale, and sets a strong limit on the power production in the unknown energy sources in the Sun of no more than 4% of the total energy production at 90% C.L.

  2. Solar Neutrinos

    Science.gov (United States)

    Davis, R. Jr.; Harmer, D. S.

    1964-12-01

    The prospect of studying the solar energy generation process directly by observing the solar neutrino radiation has been discussed for many years. The main difficulty with this approach is that the sun emits predominantly low energy neutrinos, and detectors for observing low fluxes of low energy neutrinos have not been developed. However, experimental techniques have been developed for observing neutrinos, and one can foresee that in the near future these techniques will be improved sufficiently in sensitivity to observe solar neutrinos. At the present several experiments are being designed and hopefully will be operating in the next year or so. We will discuss an experiment based upon a neutrino capture reaction that is the inverse of the electron-capture radioactive decay of argon-37. The method depends upon exposing a large volume of a chlorine compound, removing the radioactive argon-37 and observing the characteristic decay in a small low-level counter.

  3. Calibration of the solar neutrino detectors

    Energy Technology Data Exchange (ETDEWEB)

    Caccianiga, Barbara; Re, Alessandra Carlotta [Universita degli Studi Milano (Italy); INFN, Milano (Italy)

    2016-04-15

    Calibrations have been crucial for the success of solar neutrino experiments. In this contribution we review the calibration strategies adopted by different solar neutrino experiments. In particular, we will emphasize their common critical aspects and their main differences. In order to do so, we will schematically divide the solar neutrino experiments in two groups: those based on radiochemical techniques, i.e. Homestake, Gallex/GNO, SAGE and those based on real-time techniques i.e. Kamiokande, Super-Kamiokande, SNO, Borexino and KamLAND. (orig.)

  4. α/β discrimination in Borexino

    Energy Technology Data Exchange (ETDEWEB)

    Galbiati, C. [Princeton University, Physics Department, Princeton, NJ (United States); Misiaszek, M. [Jagiellonian University, M. Smoluchowski Institute of Physics, Krakow (Poland); INFN Laboratori Nazionali del Gran Sasso, Assergi (Italy); Rossi, N. [INFN Laboratori Nazionali del Gran Sasso, Assergi (Italy)

    2016-04-15

    In this report we describe the unique capabilities of the α/β discrimination of the Borexino experiment. This capability is the direct result of years of development aimed at the design of an experiment that could withstand contamination from α-emitting nuclides. The combination of the excellent α/β discrimination and of the excellent radiopurity of the detector permitted to extract information on the solar neutrino interactions in Borexino without interference from α particles. (orig.)

  5. The Borexino purification system

    Science.gov (United States)

    Benziger, Jay

    2014-05-01

    Purification of 278 tons of liquid scintillator and 889 tons of buffer shielding for the Borexino solar neutrino detector is performed with a system of combined distillation, water extraction, gas stripping and filtration. The purification system removed K, U and Th by distillation of the pseudocumene solvent and the PPO fluor. Noble gases, Rn, Kr and Ar were removed by gas stripping. Distillation was also employed to remove optical impurities and reduce the attenuation of scintillation light. The success of the purification system has facilitated the first time real time detection of low energy solar neutrinos.

  6. Homestake result, sterile neutrinos and low energy solar neutrino experiments

    CERN Document Server

    De Holanda, P C

    2003-01-01

    The large mixing (LMA) MSW solution predicts ~2-sigma higher Ar-production rate, Q_{Ar}, than the Homestake result. Also there is no apparent upturn of the spectrum (R=N_obs/N_SSM) at low energies in SNO and Super-Kamiokande (SK). Both these facts can be explained if a light, \\Delta m^2_{01} ~ (2 - 20)10^{-5} eV^2, sterile neutrino exists which mixes very weakly with active neutrinos: sin^2 2\\alpha ~ (10^{-5} - 10^{-3}). We perform both the analytical and numerical study of conversion effects in the system of two active neutrinos with the LMA parameters and one weakly mixed sterile neutrino. The presence of sterile neutrino leads to a dip in the survival probability in the intermediate energy range E = (0.5 - 5) MeV thus suppressing the Be, or/and pep, CNO as well as B neutrino fluxes. Apart from diminishing Q_{Ar} it leads also to decrease of the Ge-production rate and may lead to decrease of the BOREXINO signal and CC/NC ratio at SNO. Future studies of the solar neutrinos by SNO, SK, BOREXINO and KamLAND as...

  7. Solar neutrinos and neutrino physics

    CERN Document Server

    Maltoni, Michele

    2015-01-01

    Solar neutrino studies triggered and largely motivated the major developments in neutrino physics in the last 50 years. Theory of neutrino propagation in different media with matter and fields has been elaborated. It includes oscillations in vacuum and matter, resonance flavor conversion and resonance oscillations, spin and spin-flavor precession, etc. LMA MSW has been established as the true solution of the solar neutrino problem. Parameters theta12 and Delta_m21^2 have been measured; theta13 extracted from the solar data is in agreement with results from reactor experiments. Solar neutrino studies provide a sensitive way to test theory of neutrino oscillations and conversion. Characterized by long baseline, huge fluxes and low energies they are a powerful set-up to search for new physics beyond the standard 3nu paradigm: new neutrino states, sterile neutrinos, non-standard neutrino interactions, effects of violation of fundamental symmetries, new dynamics of neutrino propagation, probes of space and time. T...

  8. Constraining neutrino magnetic moment with solar neutrino data

    CERN Document Server

    Tortola, M A

    2003-01-01

    We use solar neutrino data to derive stringent bounds on Majorana neutrino transition moments (TMs). Such moments, if present, would contribute to the neutrino-electron scattering cross section and hence alter the signal observed in Super-Kamiokande. Using the latest solar neutrino data, combined with the results of the reactor experiment KamLAND, we perform a simultaneous fit of the oscillation parameters and TMs. Furthermore, we include data from the reactor experiments Rovno, TEXONO and MUNU in our analysis, improving significantly the current constraints on TMs. A comparison with previous works shows that our bounds are the strongest and most general results presented up to now. Finally, we perform a simulation of the future Borexino experiment and show that it will improve the bounds from today's data by order of magnitude.

  9. Large-scale liquid scintillation detectors for solar neutrinos

    Energy Technology Data Exchange (ETDEWEB)

    Benziger, Jay B.; Calaprice, Frank P. [Princeton University Princeton, Princeton, NJ (United States)

    2016-04-15

    Large-scale liquid scintillation detectors are capable of providing spectral yields of the low energy solar neutrinos. These detectors require > 100 tons of liquid scintillator with high optical and radiopurity. In this paper requirements for low-energy neutrino detection by liquid scintillation are specified and the procedures to achieve low backgrounds in large-scale liquid scintillation detectors for solar neutrinos are reviewed. The designs, operations and achievements of Borexino, KamLAND and SNO+ in measuring the low-energy solar neutrino fluxes are reviewed. (orig.)

  10. Data analysis in solar neutrinos liquid-scintillator detectors

    Energy Technology Data Exchange (ETDEWEB)

    Testera, G. [INFN, Genova (Italy)

    2016-04-15

    This paper focuses on the description of some of the methods developed to extract the solar neutrino signal from the background by the two running experiments (Borexino and Kamland) based on the use of a large volume of liquid scintillator. (orig.)

  11. A search for low-energy neutrino and antineutrino signals correlated with gamma-ray bursts with Borexino

    CERN Document Server

    Agostini, M; Appel, S; Atroshchenko, V; Bellini, G; Benziger, J; Bick, D; Bonfini, G; Bravo, D; Caccianiga, B; Calaprice, F; Caminata, A; Carlini, M; Cavalcante, P; Chepurnov, A; Choi, K; D'Angelo, D; Davini, S; de Kerret, H; Derbin, A; Di Noto, L; Drachnev, I; Etenko, A; Fomenko, K; Franco, D; Gabriele, F; Galbiati, C; Ghiano, C; Giammarchi, M; Goeger-Neff, M; Goretti, A; Gromov, M; Hagner, C; Hungerford, E; Ianni, Aldo; Ianni, Andrea; Jany, A; Jedrzejczak, K; Jeschke, D; Kobychev, V; Korablev, D; Korga, G; Kryn, D; Laubenstein, M; Lehnert, B; Litvinovich, E; Lombardi, F; Lombardi, P; Ludhova, L; Lukyanchenko, G; Machulin, I; Manecki, S; Maneschg, W; Manuzio, G; Marcocci, S; Meroni, E; Meyer, M; Miramonti, L; Misiaszek, M; Montuschi, M; Mosteiro, P; Muratova, V; Neumair, B; Oberauer, L; Obolensky, M; Ortica, F; Pallavicini, M; Papp, L; Pocar, A; Ranucci, G; Razeto, A; Re, A; Romani, A; Roncin, R; Rossi, N; Scheonert, S; Semenov, D; Skorokhvatov, M; Smirnov, O; Sotnikov, A; Sukhotin, S; Suvorov, Y; Tartaglia, R; Testera, G; Thurn, J; Toropova, M; Unzhakov, E; Vishneva, A; Vogelaar, R B; von Feilitzsch, F; Wang, H; Weinz, S; Winter, J; Wojcik, M; Wurm, M; Yokley, Z; Zaimidoroga, O; Zavatarelli, S; Zuber, K; Zuzel, G

    2016-01-01

    A search for neutrino and antineutrino events correlated with 2,350 gamma-ray bursts (GRBs) is performed with Borexino data collected between December 2007 and November 2015. No statistically significant excess over background is observed. We look for electron antineutrinos ($\\bar{\

  12. Overview and accomplishments of the Borexino experiment

    Science.gov (United States)

    Ranucci, G.; Agostini, M.; Appel, S.; Bellini, G.; Benziger, J.; Bick, D.; Bonfini, G.; Bravo, D.; Caccianiga, B.; Calaprice, F.; Caminata, A.; Cavalcante, P.; Chepurnov, A.; D'Angelo, D.; Davini, S.; Derbin, A.; Di Noto, L.; Drachnev, I.; Etenko, A.; Fomenko, K.; Franco, D.; Gabriele, F.; Galbiati, C.; Ghiano, C.; Giammarchi, M.; Goeger-Neff, M.; Goretti, A.; Gromov, M.; Hagner, C.; Hungerford, E.; Ianni, Aldo; Ianni, Andrea; Jedrzejczak, K.; Kaiser, M.; Kobychev, V.; Korablev, D.; Korga, G.; Kryn, D.; Laubenstein, M.; Lehnert, B.; Litvinovich, E.; Lombardi, F.; Lombardi, P.; Ludhova, L.; Lukyanchenko, G.; Machulin, I.; Manecki, S.; Maneschg, W.; Marcocci, S.; Meroni, E.; Meyer, M.; Miramonti, L.; Misiaszek, M.; Montuschi, M.; Mosteiro, P.; Muratova, V.; Neumair, B.; Oberauer, L.; Obolensky, M.; Ortica, F.; Pallavicini, M.; Papp, L.; Perasso, L.; Pocar, A.; Razeto, A.; Re, A.; Romani, A.; Roncin, R.; Rossi, N.; Schönert, S.; Semenov, D.; Simgen, H.; Skorokhvatov, M.; Smirnov, O.; Sotnikov, A.; Sukhotin, S.; Suvorov, Y.; Tartaglia, R.; Testera, G.; Thurn, J.; Toropova, M.; Unzhakov, E.; Vishneva, A.; Vogelaar, R. B.; von Feilitzsch, F.; Wang, H.; Weinz, S.; Winter, J.; Wojcik, M.; Wurm, M.; Yokley, Z.; Zaimidoroga, O.; Zavatarelli, S.; Zuber, K.; Zuzel, G.

    2016-02-01

    The Borexino experiment is running at the Laboratori del Gran Sasso in Italy since 2007. Its technical distinctive feature is the unprecedented ultralow background of the inner scintillating core, which is the basis of the outstanding achievements accumulated by the experiment. In this talk, after recalling the main features of the detector, the impressive solar data gathered so far by the experiment will be summarized, with special emphasis to the most recent and prominent result concerning the detection of the fundamental pp solar neutrino flux, which is the direct probe of the engine mechanism powering our star. Such a milestone measurement puts Borexino in the unique situation of being the only experiment able to do solar neutrino spectroscopy over the entire solar spectrum; the counterpart of this peculiar status in the oscillation interpretation of the data is the capability of Borexino alone to perform the full validation across the solar energy range of the MSW-LMA paradigm. The talk will be concluded highlighting the perspectives for the final stage of the solar program of the experiment, centered on the goal to fully complete the solar spectroscopy with the missing piece of the CNO neutrinos. If successful, such a measurement would represent the final crowning of the long quest of Borexino to unravel all the properties of the neutrinos from the Sun.

  13. Solar Neutrinos

    Directory of Open Access Journals (Sweden)

    V. Antonelli

    2013-01-01

    relevant indications on the fundamental interactions among particles. After reviewing the striking results of the last two decades, which were determinant to solve the long standing solar neutrino puzzle and refine the Standard Solar Model, we focus our attention on the more recent results in this field and on the experiments presently running or planned for the near future. The main focus at the moment is to improve the knowledge of the mass and mixing pattern and especially to study in detail the lowest energy part of the spectrum, which represents most of the solar neutrino spectrum but is still a partially unexplored realm. We discuss this research project and the way in which present and future experiments could contribute to make the theoretical framework more complete and stable, understanding the origin of some “anomalies” that seem to emerge from the data and contributing to answer some present questions, like the exact mechanism of the vacuum to matter transition and the solution of the so-called solar metallicity problem.

  14. Solar neutrinos and neutrino physics

    Energy Technology Data Exchange (ETDEWEB)

    Maltoni, Michele [Universidad Autonoma de Madrid, Instituto de Fisica Teorica UAM/CSIC, Madrid (Spain); Smirnov, Alexei Yu. [Max-Planck Institute for Nuclear Physics, Heidelberg (Germany); ICTP, Trieste (Italy)

    2016-04-15

    Solar neutrino studies triggered and largely motivated the major developments in neutrino physics in the last 50 years. The theory of neutrino propagation in different media with matter and fields has been elaborated. It includes oscillations in vacuum and matter, resonance flavor conversion and resonance oscillations, spin and spin-flavor precession, etc. LMA MSW has been established as the true solution of the solar neutrino problem. Parameters θ{sub 12} and Δm{sup 2}{sub 21} have been measured; θ{sub 13} extracted from the solar data is in agreement with results from reactor experiments. Solar neutrino studies provide a sensitive way to test theory of neutrino oscillations and conversion. Characterized by long baseline, huge fluxes and low energies they are a powerful set-up to search for new physics beyond the standard 3ν paradigm: new neutrino states, sterile neutrinos, non-standard neutrino interactions, effects of violation of fundamental symmetries, new dynamics of neutrino propagation, probes of space and time. These searches allow us to get stringent, and in some cases unique bounds on new physics. We summarize the results on physics of propagation, neutrino properties and physics beyond the standard model obtained from studies of solar neutrinos. (orig.)

  15. Implications of new GALLEX results for the Mikheyev-Smirnov-Wolfenstein solution of the solar neutrino problem

    Science.gov (United States)

    Gelb, James M.; Kwong, Waikwok; Rosen, S. P.

    1992-01-01

    We compare the implications for Be-7 and pp neutrinos of the two Mikheyev-Smirnov-Wolfenstein fits to the new GALLEX solar neutrino measurements. Small-mixing-angle solutions tend to suppress the former as electron neutrinos, but not the latter, and large-angle solutions tend to reduce both by about a factor of two. The consequences for BOREXINO and similar solar neutrino-electron scattering experiments are discussed.

  16. Future Solar Neutrino Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Nakahata, M. [Kamioka Observatory, Institute for Cosmic Ray research, University of Tokyo, Higashi-Mozumi, Kamioka-cho, Hida-shi, Gifu, Japan, 506-1205 (Japan)]. E-mail: nakahata@suketto.icrr.u-tokyo.ac.jp

    2005-08-15

    The value of future solar neutrino experiments is discussed from particle physics and astrophysics points of view based on current understanding of solar neutrino oscillations. R and D statuses of future experiments are also discussed.

  17. Solar Neutrino Decay

    CERN Document Server

    Acker, A; Acker, Andy; Pakvasa, Sandip

    1994-01-01

    We re-examine the neutrino decay solution to the solar neutrino problem in light of the new data from Gallex II and Kamiokande III. We compare the experimental data with the solar models of Bahcall and Pinsonneault and Turck-Chieze and find that neutrino decay is ruled out as a solution to the solar neutrino problem at better than the 98\\% c.l. even when solar model uncertainties are taken into account.

  18. Astroparticle physics with solar neutrinos

    OpenAIRE

    2011-01-01

    Solar neutrino experiments observed fluxes smaller than the expectations from the standard solar model. This discrepancy is known as the “solar neutrino problem”. Flux measurements by Super-Kamiokande and SNO have demonstrated that the solar neutrino problem is due to neutrino oscillations. Combining the results of all solar neutrino experiments, parameters for solar neutrino oscillations are obtained. Correcting for the effect of neutrino oscillations, the observed neutrino fluxes are consis...

  19. Impact on Astrophysics and Elementary Particle Physics of recent and future solar neutrino data

    OpenAIRE

    Antonelli, Vito; Miramonti, Lino

    2013-01-01

    The study of neutrinos is fundamental to connect astrophysics and elementary particle physics. In this last decade solar neutrino experiments and KamLAND confirmed the LMA solution and further clarified the mass and oscillation pattern. Borexino attacked also the study of the low energy neutrino spectrum. However, important points still need clarification, like the apparent anomaly in the vacuum to matter transition region. Besides, a more detailed study of the low energy components of the pp...

  20. Standard physics solution to the solar neutrino problem?

    Energy Technology Data Exchange (ETDEWEB)

    Dar, A. [Technion-Israel Inst. of Tech., Haifa (Israel). Dept. of Physics

    1996-11-01

    The {sup 8}B solar neutrino flux predicted by the standard solar model (SSM) is consistent within the theoretical and experimental uncertainties with that at Kamiokande. The Gallium and Chlorine solar neutrino experiments, however, seem to imply that the {sup 7}Be solar neutrino flux is strongly suppressed compared with that predicted by the SSM. If the {sup 7}Be solar neutrino flux is suppressed, still it can be due to astrophysical effects not included in the simplistic SSM. Such effects include short term fluctuations or periodic variation of the temperature in the solar core, rotational mixing of {sup 3}He in the solar core, and dense plasma effects which may strongly enhance p-capture by {sup 7}Be relative to e-capture. The new generation of solar observations which already look non stop deep into the sun, like Superkamiokande through neutrinos, and SOHO and GONG through acoustic waves, may point at the correct solution. Only Superkamiokande and/or future solar neutrino experiments, such as SNO, BOREXINO and HELLAZ, will be able to find out whether the solar neutrino problem is caused by neutrino properties beyond the minimal standard electroweak model or whether it is just a problem of the too simplistic standard solar model. (author) 1 fig., 3 tabs., refs.

  1. Future Solar Neutrino Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, Y. [Kamioka Observatory, Institute for Cosmic Ray Research, University of Tokyo, Higashi-Mozumi, Kamioka-cho, Hida-city, 506-1205 (Japan)]. E-mail: suzuki@suketto.icrr.u-tokyo.ac.jp

    2005-06-15

    The purpose of the future solar neutrino experiments is briefly reviewed. The future experimental programs which aim to measure the low energy solar neutrinos are described. We do not cover all the projects. Experiments using noble gases are promising for the pp-neutrino measurements.

  2. How to observe 8B solar neutrinos in liquid scintillator detectors

    CERN Document Server

    Ianni, A; Villante, F L

    2016-01-01

    We show that liquid organic scintillator detectors (e.g., KamLAND and Borexino) can measure the 8B solar neutrino flux by means of the nu_e charged current interaction with the 13C nuclei naturally contained in the scintillators. The neutrino events can be identified by exploiting the time and space coincidence with the subsequent decay of the produced 13N nuclei. We perform a detailed analysis of the background in KamLAND, Borexino and in a possible liquid scintillator detector at SNOLab, showing that the 8B solar neutrino signal can be extracted with a reasonable uncertainty in a few years of data taking. KamLAND should be able to extract about 18 solar neutrino events from the already collected data. Prospects for gigantic scintillator detectors (such as LENA) are also studied.

  3. Solar neutrino experiments

    Energy Technology Data Exchange (ETDEWEB)

    Hampel, W. [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany)

    1996-11-01

    The present status of experimental solar neutrino research is reviewed. Updated results from the Homestake, Kamiokande, GALLEX and SAGE detectors all show a deficit when compared to recent standard solar model calculations. Two of these detectors, GALLEX and SAGE, have recently been checked with artificial {sup 51}Cr neutrino sources. It is shown that astrophysical scenarios to solve the solar neutrino problems are not favoured by the data. There is hope that the results of forthcoming solar neutrino experiments can provide the answers to the open questions. (author) 6 figs., 3 tabs., 36 refs.

  4. Solar neutrino detection

    CERN Document Server

    Miramonti, Lino

    2009-01-01

    More than 40 years ago, neutrinos where conceived as a way to test the validity of the solar models which tell us that stars are powered by nuclear fusion reactions. The first measurement of the neutrino flux, in 1968 in the Homestake mine in South Dakota, detected only one third of the expected value, originating what has been known as the Solar Neutrino Problem. Different experiments were built in order to understand the origin of this discrepancy. Now we know that neutrinos undergo oscillation phenomenon changing their nature traveling from the core of the Sun to our detectors. In the work the 40 year long saga of the neutrino detection is presented; from the first proposals to test the solar models to last real time measurements of the low energy part of the neutrino spectrum.

  5. Setup of a drift tube muon tracker and calibration of muon tracking in Borexino

    Energy Technology Data Exchange (ETDEWEB)

    Bick, Daniel

    2011-04-15

    In this work the setup and commissioning of a drift tube based 3D muon tracking detector are described and its use for the solar neutrino experiment Borexino is presented. After a brief introduction to neutrino physics, the general layout of the detector is presented. It is followed by the description of the reconstruction and calibration algorithms. The performance of the muon tracker is presented and results from the commissioning in Hamburg are shown. The detector is currently operated in the LNGS underground laboratory in Italy at the Borexino experiment. After an introduction to Borexino, the modifications of the muon tracker for its setup at LNGS are described. The setup is used as a reference system to determine the resolution of the Borexino muon tracking which is essential for the tagging of cosmogenic induced {sup 11}C background. Finally, first results are presented. (orig.)

  6. Neutrino decay and solar neutrino seasonal effect

    Directory of Open Access Journals (Sweden)

    R. Picoreti

    2016-10-01

    Full Text Available We consider the possibility of solar neutrino decay as a sub-leading effect on their propagation between production and detection. Using current oscillation data, we set a new lower bound to the ν2 neutrino lifetime at τ2/m2≥7.2×10−4s.eV−1 at 99% C.L. Also, we show how seasonal variations in the solar neutrino data can give interesting additional information about neutrino lifetime.

  7. Neutrino decay and solar neutrino seasonal effect

    Science.gov (United States)

    Picoreti, R.; Guzzo, M. M.; de Holanda, P. C.; Peres, O. L. G.

    2016-10-01

    We consider the possibility of solar neutrino decay as a sub-leading effect on their propagation between production and detection. Using current oscillation data, we set a new lower bound to the ν2 neutrino lifetime at τ2 /m2 ≥ 7.2 ×10-4s .eV-1 at 99% C.L. Also, we show how seasonal variations in the solar neutrino data can give interesting additional information about neutrino lifetime.

  8. Solar Neutrino Data, Solar Model Uncertainties and Neutrino Oscillations

    CERN Document Server

    Krauss, L M; White, M; Krauss, Lawrence M.; Gates, Evalyn; White, Martin

    1993-01-01

    We incorporate all existing solar neutrino flux measurements and take solar model flux uncertainties into account in deriving global fits to parameter space for the MSW and vacuum solutions of the solar neutrino problem.

  9. Solar Neutrino Data, Solar Model Uncertainties and Neutrino Oscillations

    OpenAIRE

    1992-01-01

    We incorporate all existing solar neutrino flux measurements and take solar model flux uncertainties into account in deriving global fits to parameter space for the MSW and vacuum solutions of the solar neutrino problem.

  10. Astroparticle physics with solar neutrinos.

    Science.gov (United States)

    Nakahata, Masayuki

    2011-01-01

    Solar neutrino experiments observed fluxes smaller than the expectations from the standard solar model. This discrepancy is known as the "solar neutrino problem". Flux measurements by Super-Kamiokande and SNO have demonstrated that the solar neutrino problem is due to neutrino oscillations. Combining the results of all solar neutrino experiments, parameters for solar neutrino oscillations are obtained. Correcting for the effect of neutrino oscillations, the observed neutrino fluxes are consistent with the prediction from the standard solar model. In this article, results of solar neutrino experiments are reviewed with detailed descriptions of what Kamiokande and Super-Kamiokande have contributed to the history of astroparticle physics with solar neutrino measurements. (Communicated by Toshimitsu Yamazaki, M.J.A.).

  11. Towards the resolution of the solar neutrino problem

    Energy Technology Data Exchange (ETDEWEB)

    Friedland, Alexander

    2000-08-29

    A number of experiments have accumulated over the years a large amount of solar neutrino data. The data indicate that the observed solar neutrino flux is significantly smaller than expected and, furthermore, that the electron neutrino survival probability is energy dependent. This ''solar neutrino problem'' is best solved by assuming that the electron neutrino oscillates into another neutrino species. Even though one can classify the solar neutrino deficit as strong evidence for neutrino oscillations, it is not yet considered a definitive proof. Traditional objections are that the evidence for solar neutrino oscillations relies on a combination of hard, different experiments, and that the Standard Solar Model (SSM) might not be accurate enough to precisely predict the fluxes of different solar neutrino components. Even though it seems unlikely that modifications to the SSM alone can explain the current solar neutrino data, one still cannot completely discount the possibility that a combination of unknown systematic errors in some of the experiments and certain modifications to the SSM could conspire to yield the observed data. To conclusively demonstrate that there is indeed new physics in solar neutrinos, new experiments are aiming at detecting ''smoking gun'' signatures of neutrino oscillations, such as an anomalous seasonal variation in the observed neutrino flux or a day-night variation due to the regeneration of electron neutrinos in the Earth. In this dissertation we study the sensitivity reach of two upcoming neutrino experiments, Borexino and KamLAND, to both of these effects. Results of neutrino oscillation experiments for the case of two-flavor oscillations have always been presented on the (sin{sup 2} 2{theta}, {Delta}m{sup 2}) parameter space. We point out, however, that this parameterization misses the half of the parameter space {pi}/4 < {theta} {le} {pi}/2, which is physically inequivalent to the region 0 {le

  12. Impact on Astrophysics and Elementary Particle Physics of recent and future Solar Neutrino data

    Science.gov (United States)

    Antonelli, V.; Miramonti, L.

    2014-06-01

    The study of neutrinos is fundamental to connect astrophysics and elementary particle physics. In this last decade solar neutrino experiments and Kam-LAND confirmed the LMA solution and further clarified the oscillation pattern. Borexino attacked also the study of the low energy neutrino spectrum. However, important points still need clarification, like the apparent anomaly in the vacuum to matter transition region. Besides, a more detailed study of the low energy components of the pp cycle, combined with a measurement of CNO fluxes, is compulsory, also to discriminate between the low and the high Z versions of the Solar Standard Models and solve the metallicity problem. We discuss the main recent advancements and the possibilities of studying these open problems with Borexino, SNO+ and the future experiments, like the next generation of scintillators.

  13. Impact on Astrophysics and Elementary Particle Physics of recent and future solar neutrino data

    CERN Document Server

    Antonelli, Vito

    2013-01-01

    The study of neutrinos is fundamental to connect astrophysics and elementary particle physics. In this last decade solar neutrino experiments and KamLAND confirmed the LMA solution and further clarified the mass and oscillation pattern. Borexino attacked also the study of the low energy neutrino spectrum. However, important points still need clarification, like the apparent anomaly in the vacuum to matter transition region. Besides, a more detailed study of the low energy components of the pp cycle, combined with a measurement of CNO fluxes, is compulsory, also to discriminate between the low and the high Z versions of the Solar Standard Models and solve the metallicity problem. We discuss the main recent advancements and the possibilities of studying these open problems with Borexino, SNO+ and the future experiments, like the next generation of scintillators.

  14. Solar-neutrino oscillations

    Science.gov (United States)

    Krauss, L.; Wilczek, F.

    1985-01-01

    The theory of oscillations of solar neutrinos is developed as it applies to the electron-recoil spectrum in neutrino-electron scattering. The spectral information obtained by such measurements (as opposed to counting total event rates) is crucial for allowing observation of neutrino oscillations for masses down to 500 neV. In this regard, the effects of different masses and mixing angles, as well as such subtleties as thermal and pressure broadening, finite solar-core size, and variable indices of refraction are investigated.

  15. Radiochemical solar neutrino experiments

    CERN Document Server

    Gavrin, V N

    2011-01-01

    Radiochemical experiments have been crucial to solar neutrino research. Even today, they provide the only direct measurement of the rate of the proton-proton fusion reaction, p + p --> d + e^+ + nu_e, which generates most of the Sun's energy. We first give a little history of radiochemical solar neutrino experiments with emphasis on the gallium experiment SAGE -- the only currently operating detector of this type. The combined result of all data from the Ga experiments is a capture rate of 67.6 +/- 3.7 SNU. For comparison to theory, we use the calculated flux at the Sun from a standard solar model, take into account neutrino propagation from the Sun to the Earth and the results of neutrino source experiments with Ga, and obtain 67.3 ^{+3.9}_{-3.5} SNU. Using the data from all solar neutrino experiments we calculate an electron neutrino pp flux at the earth of (3.41 ^{+0.76}_{-0.77}) x 10^{10}/(cm^2-s), which agrees well with the prediction from a detailed solar model of (3.30 ^{+0.13} _{-0.14}) x 10^{10}/(cm^...

  16. Solar Neutrino Physics

    Energy Technology Data Exchange (ETDEWEB)

    Bowles, T.J.; Brice, S.J.; Esch, E.-I.; Fowler, M.M.; Goldschmidt, A.; Hime, A.; McGirt, F.; Miller, G.G.; Thornewell, P.M.; Wilhelmy, J.B.; Wouters, J.M.

    1999-07-15

    With its heavy water target, the Sudbury Neutrino Observatory (SNO) offers the unique opportunity to measure both the 8B flux of electron neutrinos from the Sun and, independently, the flux of all active neutrino species reaching the Earth. A model-independent test of the hypothesis that neutrino oscillations are responsible for the observed solar neutrino deficit can be made by comparing the charged-current (CC) and neutral-current (NC) rates. This LDRD proposal supported the research and development necessary for an assessment of backgrounds and performance of the SNO detector and the ability to extract the NC/CC-Ratio. Particular emphasis is put upon the criteria for deployment and signal extraction from a discrete NC detector array based upon ultra-low background 3He proportional counters.

  17. Solar Neutrinos. II. Experimental

    Science.gov (United States)

    Davis, Raymond Jr.

    1964-01-01

    A method is described for observing solar neutrinos from the reaction Cl{sup 37}(nu,e{sup -})Ar{sup 37} in C{sub 2}Cl{sub 4}. Two 5 00-gal tanks of C{sub 2}Cl{sub 4} were placed in a limestone mine (1800 m.w.e.) and the resulting Ar{sup 37} activity induced by cosmic mesons( mu ) was measured to determine the necessary conditions for solar neutrino observations. (R.E.U.)

  18. Recent Borexino results and prospects for the near future

    Science.gov (United States)

    D'Angelo, D.; Agostini, M.; Altenmüller, K.; Appel, S.; Bellini, G.; Benziger, J.; Bick, D.; Bonfini, G.; Bravo, D.; Caccianiga, B.; Calaprice, F.; Caminata, A.; Cavalcante, P.; Chepurnov, A.; Davini, S.; Derbin, A.; Di Noto, L.; Drachnev, I.; Etenko, A.; Fomenko, K.; Franco, D.; Gabriele, F.; Galbiati, C.; Ghiano, C.; Giammarchi, M.; Goeger-Neff, M.; Goretti, A.; Gromov, M.; Hagner, C.; Hungerford, E.; Ianni, Aldo; Ianni, Andrea; Jedrzejczak, K.; Kaiser, M.; Kobychev, V.; Korablev, D.; Korga, G.; Kryn, D.; Laubenstein, M.; Lehnert, B.; Litvinovich, E.; Lombardi, F.; Lombardi, P.; Ludhova, L.; Lukyanchenko, G.; Machulin, I.; Manecki, S.; Maneschg, W.; Marcocci, S.; Meroni, E.; Meyer, M.; Miramonti, L.; Misiaszek, M.; Montuschi, M.; Mosteiro, P.; Muratova, V.; Neumair, B.; Oberauer, L.; Obolensky, M.; Ortica, F.; Pallavicini, M.; Papp, L.; Perasso, L.; Pocar, A.; Ranucci, G.; Razeto, A.; Re, A.; Romani, A.; Roncin, R.; Rossi, N.; Schönert, S.; Semenov, D.; Simgen, H.; Skorokhvatov, M.; Smirnov, O.; Sotnikov, A.; Sukhotin, S.; Suvorov, Y.; Tartaglia, R.; Testera, G.; Thurn, J.; Toropova, M.; Unzhakov, E.; Vishneva, A.; Vogelaar, R. B.; von Feilitzsch, F.; Wang, H.; Weinz, S.; Winter, J.; Wojcik, M.; Wurm, M.; Yokley, Z.; Zaimidoroga, O.; Zavatarelli, S.; Zuber, K.; Zuzel, G.

    2016-11-01

    The Borexino experiment located in the Gran Sasso National Laboratory, is an organic liquid scintillator detector conceived for the real time spectroscopy of low energy solar neutrinos. The phase-I of the data taking campaign (2007 - 2010) has allowed the first independent measurements of 7Be and pep solar neutrino fluxes as well as the first measurement of anti-neutrinos from the Earth. After a purification of the scintillator, Borexino is now in phase-II since 2011. Thanks to the unprecedented background levels, we have performed the first flux measurement of neutrinos from the fundamental pp reaction which powers the Sun. We review this breakthrough result and other recent results, including the latest review of our terrestrial neutrino analysis. We also discuss the upcoming measurements on middle energy solar neutrino spectral components (pep, CNO) and the new project SOX devoted to the study of sterile neutrinos via the use of a neutrino source placed in close proximity of the detector's active material.

  19. Recent Borexino results and prospects for the near future

    Directory of Open Access Journals (Sweden)

    D’Angelo D.

    2016-01-01

    Full Text Available The Borexino experiment located in the Gran Sasso National Laboratory, is an organic liquid scintillator detector conceived for the real time spectroscopy of low energy solar neutrinos. The phase-I of the data taking campaign (2007 – 2010 has allowed the first independent measurements of 7Be and pep solar neutrino fluxes as well as the first measurement of anti-neutrinos from the Earth. After a purification of the scintillator, Borexino is now in phase-II since 2011. Thanks to the unprecedented background levels, we have performed the first flux measurement of neutrinos from the fundamental pp reaction which powers the Sun. We review this breakthrough result and other recent results, including the latest review of our terrestrial neutrino analysis. We also discuss the upcoming measurements on middle energy solar neutrino spectral components (pep, CNO and the new project SOX devoted to the study of sterile neutrinos via the use of a neutrino source placed in close proximity of the detector’s active material.

  20. Solar models and solar neutrino oscillations

    OpenAIRE

    2004-01-01

    We provide a summary of the current knowledge, theoretical and experimental, of solar neutrino fluxes and of the masses and mixing angles that characterize solar neutrino oscillations. We also summarize the principal reasons for doing new solar neutrino experiments and what we think may be learned from the future measurements.

  1. Solving the Solar Neutrino Puzzle with KamLAND and Solar Data

    CERN Document Server

    De Gouvêa, A; Gouv\\^ea, Andr\\'e de

    2001-01-01

    We study what will be learnt about the solar neutrino puzzle and solar neutrino oscillations once the data from the KamLAND reactor neutrino experiment (soon to become available) are combined with those from the current solar neutrino experiments. We find that, in agreement with previous estimates, if the solution to the solar neutrino puzzle falls on the LMA region, KamLAND should be able to ``pin-point'' the right solution with unprecedented accuracy after a few years of data taking. Furthermore, the light side ($\\theta\\pi/4$) at the 95% confidence level (CL) for most of the LMA region allowed by the current data at the 99% CL, while the addition of the KamLAND data need not improve our ability to limit a sterile component in ``solar'' oscillations. If KamLAND does not see an oscillation signal, the solar data would point to the LOW/VAC regions, while the SMA region would still lurk at the two sigma CL, meaning we would probably have to wait for Borexino data in order to finally piece the solar neutrino puz...

  2. Solar neutrino oscillation phenomenology

    Indian Academy of Sciences (India)

    Srubabati Goswami

    2004-02-01

    This article summarises the status of the solar neutrino oscillation phenomenology at the end of 2002 in the light of the SNO and KamLAND results. We first present the allowed areas obtained from global solar analysis and demonstrate the preference of the solar data towards the large-mixing-angle (LMA) MSW solution. A clear confirmation in favour of the LMA solution comes from the KamLAND reactor neutrino data. the KamLAND spectral data in conjunction with the global solar data further narrows down the allowed LMA region and splits it into two allowed zones - a low $ m^{2}$ region (low-LMA) and high $ m^{2}$ region (high-LMA). We demonstrate through a projected analysis that with an exposure of 3 kton-year (kTy) KamLAND can remove this ambiguity.

  3. Solar Neutrino Oscillation - An Overview

    CERN Document Server

    Roy, D P

    2005-01-01

    After a brief summary of the neutrino oscillation formalism and the solar neutrino sources and experiments I discuss the matter effect on solar neutrino oscillation. Then I discuss how the resulting alternative solutions are experimentally resolved in favour of the LMA solution, with particular exphasis on the SK, SNO and KL data.

  4. Recent Borexino results and prospects for the near future

    Energy Technology Data Exchange (ETDEWEB)

    Appel, Simon; Agostini, Matteo; Altenmueller, Konrad; Goeger-Neff, Marianne; Jeschke, Dominik; Papp, Laszlo; Neumair, Birgit; Oberauer, Lothar; Schoenert, Stefan [Technische Universitaet Muenchen, Physik Department E15, James Franck Strasse, 85748 Garching (Germany); Collaboration: Borexino-Collaboration

    2015-07-01

    The Sun is an intense source of neutrinos, produced in nuclear reactions of the p-p chain and of the CNO cycle. Measurements of the individual neutrino fluxes is of paramount importance for both particle physics and astrophysics. Up to a few years ago, spectroscopical measurements were performed by water Cherenkov detectors above 5 MeV and concerned only {sup 8}B neutrinos for less then 1% of the total flux. The bulk of neutrinos at low energies were detected with radiochemical experiments, incapable of resolving the individual components. Neutrinos are emitted in the sun as electron flavour neutrinos and oscillate to a different flavour during the trajectory to the Earth. The MSW mechanism at Large Mixing Angle (LMA) foresees the survival probability for electron neutrinos on Earth. Borexino was designed to achieve spectroscopy of the low energy part of the solar neutrino spectrum, in particular the flux of the {sup 7}Be monochromatic line at 862 keV. Borexino has largely exceeded the expected performance with the physics program broadening way past the original goal.

  5. Solar neutrinos and the solar composition problem

    CERN Document Server

    Pena-Garay, Carlos

    2008-01-01

    Standard solar models (SSM) are facing nowadays a new puzzle: the solar composition problem. New determinations of solar metal abundances lead SSM calculations to conflict with helioseismological measurements, showing discrepancies that extend from the convection zone to the solar core and can not be easily assigned to deficiencies in the modelling of the solar convection zone. We present updated solar neutrino fluxes and uncertainties for two SSM with high (old) and low (new) solar metallicity determinations. The uncertainties in iron and carbon abundances are the largest contribution to the uncertainties of the solar neutrino fluxes. The uncertainty on the ^14N+p -> ^15O+g rate is the largest of the non-composition uncertainties to the CNO neutrino fluxes. We propose an independent method to help identify which SSM is the correct one. Present neutrino data can not distinguish the solar neutrino predictions of both models but ongoing measurements can help to solve the puzzle.

  6. Solar neutrino detection in a large volume double-phase liquid argon experiment

    Science.gov (United States)

    Franco, D.; Giganti, C.; Agnes, P.; Agostino, L.; Bottino, B.; Canci, N.; Davini, S.; De Cecco, S.; Fan, A.; Fiorillo, G.; Galbiati, C.; Goretti, A. M.; Hungerford, E. V.; Ianni, Al.; Ianni, An.; Jollet, C.; Marini, L.; Martoff, C. J.; Meregaglia, A.; Pagani, L.; Pallavicini, M.; Pantic, E.; Pocar, A.; Razeti, M.; Renshaw, A. L.; Rossi, B.; Rossi, N.; Suvorov, Y.; Testera, G.; Tonazzo, A.; Wang, H.; Zavatarelli, S.

    2016-08-01

    Precision measurements of solar neutrinos emitted by specific nuclear reaction chains in the Sun are of great interest for developing an improved understanding of star formation and evolution. Given the expected neutrino fluxes and known detection reactions, such measurements require detectors capable of collecting neutrino-electron scattering data in exposures on the order of 1 ktonne-yr, with good energy resolution and extremely low background. Two-phase liquid argon time projection chambers (LAr TPCs) are under development for direct Dark Matter WIMP searches, which possess very large sensitive mass, high scintillation light yield, good energy resolution, and good spatial resolution in all three cartesian directions. While enabling Dark Matter searches with sensitivity extending to the ``neutrino floor'' (given by the rate of nuclear recoil events from solar neutrino coherent scattering), such detectors could also enable precision measurements of solar neutrino fluxes using the neutrino-electron elastic scattering events. Modeling results are presented for the cosmogenic and radiogenic backgrounds affecting solar neutrino detection in a 300 tonne (100 tonne fiducial) LAr TPC operating at LNGS depth (3,800 meters of water equivalent). The results show that such a detector could measure the CNO neutrino rate with ~15% precision, and significantly improve the precision of the 7Be and pep neutrino rates compared to the currently available results from the Borexino organic liquid scintillator detector.

  7. Coherent lunar effect on solar neutrino

    CERN Document Server

    Ishikawa, K

    2005-01-01

    Coherent interaction of solar neutrino with the moon is investigated. Neutrino interacts with matters extremely weakly. So incoherent scattering event rate is negligibly small but coherent interaction of neutrino with a massive object can have a significant effect. We study coherent lunar effect on solar neutrino and show that a phase factor of the neutrino wave function is modified substantially if the neutrino penetrates through the moon. Possibility of measuring interference effect of solar neutrino during eclipse is pointed out.

  8. Update of the solar neutrino oscillation analysis with the 766 Ty KamLAND spectrum

    Energy Technology Data Exchange (ETDEWEB)

    Bandyopadhyay, Abhijit [Saha Institute of Nuclear Physics, 1/AF, Bidhannagar, Calcutta 700 064 (India); Choubey, Sandhya [INFN, Sezione di Trieste, Trieste (Italy) and Scuola Internazionale Superiore di Studi Avanzati, I-34014 Trieste (Italy)]. E-mail: sandhya@he.sissa.it; Goswami, Srubabati [Harish-Chandra Research Institute, Chhatnag Road, Jhusi, Allahabad 211 019 (India); Petcov, S.T. [Scuola Internazionale Superiore di Studi Avanzati, I-34014 Trieste (Italy); INFN, Sezione di Trieste, Trieste (Italy); Institute of Nuclear Research and Nuclear Energy, Bulgarian Academy of Sciences, Sofia (Bulgaria); Roy, D.P. [Abdus Salam International Centre for Theoretical Physics, I-34100 Trieste (Italy); Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400 005 (India)

    2005-02-17

    We investigate the impact of the 766.3 Ty KamLAND spectrum data on the determination of the solar neutrino oscillation parameters. We show that the observed spectrum distortion in the KamLAND experiment firmly establishes {delta}m{sub 21}{sup 2} to lie in the low-LMA solution region. The high-LMA solution is excluded at more than 4{sigma} by the global solar neutrino and KamLAND spectrum data. The maximal solar neutrino mixing is ruled out at 6{sigma} level. The 3{sigma} allowed region in the {delta}m{sub 21}{sup 2}-sin{sup 2}{theta}{sub 12} plane is found to be remarkably stable with respect to leaving out the data from one of the solar neutrino experiments from the global analysis. We perform a three flavor neutrino oscillation analysis of the global solar neutrino and KamLAND spectrum data as well. The 3{sigma} upper limit on sin{sup 2}{theta}{sub 13} is found to be sin{sup 2}{theta}{sub 13}<0.055. We derive predictions for the CC to NC event rate ratio and day-night (D-N) asymmetry in the CC event rate, measured in the SNO experiment, and for the suppression of the event rate in the BOREXINO and LowNu experiments. Prospective high precision measurements of the solar neutrino oscillation parameters are also discussed.

  9. Short review on solar neutrinos experiments and search for sterile neutrinos with solar neutrino detectors

    Directory of Open Access Journals (Sweden)

    Pallavicini Marco

    2015-01-01

    Full Text Available The spectroscopy of solar neutrinos is now entering the precision era, after a golden age which has led to the discovery of neutrino oscillations and the MSW effect. In this paper we summarise the current experimental knowledge in the field and its future perspectives, showing that solar neutrino detectors are and will remain a crucial tool for a deeper understanding of stars, neutrinos, and fundamental physics. We also show that solar neutrinos may become pivotal for the search of sterile neutrinos.

  10. Solar neutrino spectrum, sterile neutrinos and additional radiation in the Universe

    Energy Technology Data Exchange (ETDEWEB)

    Holanda, Pedro Cunha de [Universidade de Campinas (DRCC/IFGW/UNICAMP), SP (Brazil). Inst. de Fisica Gleb Wataghin. Dept. de Raios Cosmicos e Cronologia; Smirnov, Alexei Yu [The Abdus Salam International Centre for Theoretical Physics (ICTP), Trieste (Italy)

    2011-07-01

    Full text: Recent results from the SNO, Super-Kamiokande and Borexino experiments do not show the expected upturn of the energy spectrum of events (the ratio R {identical_to} N{sub obs}/N{sub SSM}) at low energies. At the same time, cosmological observations testify for possible existence of additional relativistic degrees of freedom in the early Universe: {Delta}N{sub eff} = 1 - 2. These facts strengthen the case of very light sterile neutrino, {nu}{sub s}, with {Delta}m{sub 0}1{sup 2} {approx} (0.7 - 2) . 10{sup -5} e V{sup 2}, which mixes weakly with the active neutrinos. The {nu}{sub s} mixing in the mass eigenstate {nu}{sub 1} characterized by sin{sup 2} 2{proportional_to} {approx} 10{sup -3} can explain an absence of the upturn. The mixing of {nu}{sub s} in the eigenstate {nu}{sub 3} with sin{sup 2} {beta} {approx} 0.1 leads to production of {nu}{sub s} via oscillations in the Universe and to additional contribution {Delta} N{sub eff} {approx} 0.7 -1 before the big bang nucleosynthesis and later. Such a mixing can be tested in forthcoming experiments with the atmospheric neutrinos as well as in future accelerator long baseline experiments. It has substantial impact on conversion of the supernova neutrinos. We perform a qualitative and quantitative analysis of solar neutrino data including a fourth neutrino with different mixings with the active neutrino sector.(author)

  11. Solar neutrino experiments: now and future

    CERN Document Server

    Nakahata, M

    2003-01-01

    The deficit of the solar neutrino event rate (so called 'solar neutrino problem') was initially presented by Davis since 1960s. It was established as a deficit of the solar neutrino flux by Kamiokande led by Koshiba. In the recent two years, it was found that the solar neutrino problem is due to neutrino oscillations by the results from Super-Kamiokande and SNO experiments. Combining with other solar neutrino experiments, most probable solution of the neutrino oscillation parameters was the Large Mixing Angle (LMA) solution. In December 2002, the reactor long baseline experiment, KamLAND, confirmed that the LMA is the correct solution. (author)

  12. Reconciling dark matter, solar and atmospheric neutrinos

    CERN Document Server

    Peltoniemi, J T

    1993-01-01

    We present models that can reconcile the solar and atmospheric neutrino data with the existence of a hot dark matter component in the universe. This dark matter is a quasi-Dirac neutrino whose mass $m_{DM}$ arises at the one-loop level. The solar neutrino deficit is explained via nonadiabatic conversions of electron neutrino to a sterile neutrino and the atmospheric neutrino data via maximal muon neutrino to tau neutrino oscillations generated by higher order loop diagrams. For $m_{DM} \\sim 30$ eV the radiative neutrino decay can lead to photons that can ionize interstellar hydrogen. In one of the models one can have observable $\

  13. Seasonal modulation in the Borexino cosmic muon signal

    CERN Document Server

    D'Angelo, Davide

    2011-01-01

    Borexino is an organic liquid scintillator detector located in the underground Gran Sasso National Laboratory (Italy). It is devoted mainly to the real time spectroscopy of low energy solar neutrinos via the elastic scattering on electrons in the target mass. The data taking campaign started in 2007 and led to key measurements of 7}Be and 8B solar neutrinos as well as antineutrinos from the earth (geo-neutrinos) and from nuclear power reactors. Borexino is also a powerful tool for the study of cosmic muons that penetrate the Gran Sasso rock coverage and thereby induced signals such as neutrons and radioactive isotopes which are today of critical importance for upcoming dark matter and neutrino physics experiments. Having reached 4y of continuous data taking we analyze here the muon signal and its possible modulation. The muon flux is measured to be (3.41+-0.01)E-4/m2/s. A modulation of this signal with a yearly period is observed with an amplitude of (1.29+-0.07)% and a phase of (179+-6) d, corresponding to J...

  14. Neutrino Cross Sections at Solar Energies

    Science.gov (United States)

    Strigari, Louis

    2017-01-01

    I will review neutrino nucleus cross section measurements and uncertainties for energies applicable to solar neutrinos. I will discuss how these cross sections are important for interpreting solar neutrino experimental data, and highlight the most important neutrino-nucleus interactions that will be relevant for forthcoming dark matter direct detection experiments. NSF PHY-1522717.

  15. Global analysis of solar neutrinos

    Energy Technology Data Exchange (ETDEWEB)

    Choubey, Sandhya [Department of Physics and Astronomy, University of Southampton, Highfield, Southampton S017 1BJ (United Kingdom)

    2003-08-01

    The recent data from SNO are analysed with the global data from the other solar neutrino experiments, first in a model independent way and then assuming two-flavour oscillations. Neutrino oscillations to active flavours can best explain the global data with the LMA solution emerging as the best-fit. However, transitions to 'mixed' states with up to 30% sterile mixture are still allowed at 1{sigma}.

  16. Solar mass-varying neutrino oscillations.

    Science.gov (United States)

    Barger, V; Huber, Patrick; Marfatia, Danny

    2005-11-18

    We propose that the solar neutrino deficit may be due to oscillations of mass-varying neutrinos (MaVaNs). This scenario elucidates solar neutrino data beautifully while remaining comfortably compatible with atmospheric neutrino and K2K data and with reactor antineutrino data at short and long baselines (from CHOOZ and KamLAND). We find that the survival probability of solar MaVaNs is independent of how the suppression of neutrino mass caused by the acceleron-matter couplings varies with density. Measurements of MeV and lower energy solar neutrinos will provide a rigorous test of the idea.

  17. Solar neutrinos: Oscillations or No-oscillations?

    CERN Document Server

    Smirnov, A Yu

    2016-01-01

    The Nobel prize in physics 2015 has been awarded "... for the discovery of neutrino oscillations which show that neutrinos have mass". While SuperKamiokande (SK), indeed, has discovered oscillations, SNO observed effect of the adiabatic (almost non-oscillatory) flavor conversion of neutrinos in the matter of the Sun. Oscillations are irrelevant for solar neutrinos apart from small $\

  18. Constraints on three flavor neutrino mixing

    Indian Academy of Sciences (India)

    Mohan Narayan

    2000-01-01

    We summarize the constraints on three flavor neutrino mixing coming from data. We first map out the allowed region in the three neutrino parameter space using solar and atmospheric neutrino data. We then incorporate the results of reactor and long baseline experiments in our analysis and show that the parameter space is drastically reduced. We conclude by pointing out that the results of Borexino and SNO will further help in constraining the parameter space.

  19. Neutrinos do come from solar-fusion

    CERN Multimedia

    1990-01-01

    Results from Kamiokande 11 have given the first convincing evidence that neutrinos are emitted by nuclear fusion in the sun. However, the measured neutrino flux is less than half that predicted by the standard solar model (4 paragraphs).

  20. Measurements of extremely low radioactivity levels in BOREXINO

    CERN Document Server

    Arpesella, C

    2001-01-01

    The techniques researched, developed and applied towards the measurement of radioisotope concentrations at ultra-low levels in the real-time solar neutrino experiment BOREXINO at Gran Sasso are presented and illustrated with specific results of widespread interest. We report the use of low-level germanium gamma spectrometry, low-level miniaturized gas proportional counters and low background scintillation detectors developed in solar neutrino research. Each now sets records in its field. We additionally describe our techniques of radiochemical ultra-pure, few atom manipulations and extractions. Forefront measurements also result from the powerful combination of neutron activation and low-level counting. Finally, with our techniques and commercially available mass spectrometry and atomic absorption spectroscopy, new low-level detection limits for isotopes of interest are obtained.

  1. Are solar neutrino oscillations robust?

    CERN Document Server

    Miranda, O G; Valle, J W F

    2006-01-01

    Prompted by the recent 766.3 ton-yr data sample just released by the KamLAND collaboration we have reconsidered the status of the large mixing angle (LMA) oscillation (OSC) interpretation of the data in a more general framework where non-standard neutrino interactions (NSI) are present. Such interactions may be regarded as a generic feature of actual models of neutrino mass. This implies the existence of three LMA solutions, instead of the unique solution which holds in the absence of NSI, LMA-I. Moreover, in addition to the two ``light-side'' OSC+NSI solutions LMA-0 and LMA-I, there is a new ``dark-side'' solution (LMA-D) with sin^2 theta_Sol = 0.70. We give the status of all LMA OSC and OSC+NSI solutions in view of the latest solar and KamLAND data. It is unlikely that more precise KamLAND measurements will resolve the ambiguity in the determination of the solar neutrino mixing angle theta_Sol, as they are expected to constrain mainly Delta m^2. We comment on the potential of future solar neutrino experimen...

  2. Updating neutrino magnetic moment constraints

    Directory of Open Access Journals (Sweden)

    B.C. Cañas

    2016-02-01

    Full Text Available In this paper we provide an updated analysis of the neutrino magnetic moments (NMMs, discussing both the constraints on the magnitudes of the three transition moments Λi and the role of the CP violating phases present both in the mixing matrix and in the NMM matrix. The scattering of solar neutrinos off electrons in Borexino provides the most stringent restrictions, due to its robust statistics and the low energies observed, below 1 MeV. Our new limit on the effective neutrino magnetic moment which follows from the most recent Borexino data is 3.1×10−11μB at 90% C.L. This corresponds to the individual transition magnetic moment constraints: |Λ1|≤5.6×10−11μB, |Λ2|≤4.0×10−11μB, and |Λ3|≤3.1×10−11μB (90% C.L., irrespective of any complex phase. Indeed, the incoherent admixture of neutrino mass eigenstates present in the solar flux makes Borexino insensitive to the Majorana phases present in the NMM matrix. For this reason we also provide a global analysis including the case of reactor and accelerator neutrino sources, presenting the resulting constraints for different values of the relevant CP phases. Improved reactor and accelerator neutrino experiments will be needed in order to underpin the full profile of the neutrino electromagnetic properties.

  3. Variations in the Solar Neutrino Flux

    Science.gov (United States)

    Davis, R. Jr.; Cleveland, B. T.; Rowley, J. K.

    1987-08-02

    Observations are reported from the chlorine solar neutrino detector in the Homestake Gold Mine, South Dakota, USA. They extend from 1970 to 1985 and yield an average neutrino capture rate of 2.1 +- 0.3 SNU. The results from 1977 to 1985 show an anti-correlation with the solar activity cycle, and an apparent increased rate during large solar flares.

  4. Solar neutrino spectrum, sterile neutrinos and additional radiation in the Universe

    CERN Document Server

    de Holanda, P C

    2010-01-01

    Recent results from the SNO, Super-Kamiokande and Borexino experiments do not show the expected upturn of the energy spectrum of events (the ratio $R \\equiv N_{obs}/N_{SSM}$) at low energies. At the same time, cosmological observations testify for possible existence of additional relativistic degrees of freedom in the early Universe: $\\Delta N_{eff} = 1 - 2$. These facts strengthen the case of very light sterile neutrino, $\

  5. Bounds on neutrino magnetic moment tensor from solar neutrinos

    CERN Document Server

    Joshipura, A S; Joshipura, Anjan S.; Mohanty, Subhendra

    2002-01-01

    Solar neutrinos with non-zero magnetic moments will contribute to the electron scattering rates in the Super-Kamiokande experiment. The magnetic moment scattering events in Super-K can be accommodated in the standard VO or MSW solutions by a change of the parameter space of mass square difference and mixing angle-but the shifted neutrino parameters obtained from Super-K will (for some values of neutrino magnetic moments) become incompatible with the fits from SNO, Gallium and Chlorine experiments. We compute the upper bounds on the Dirac and Majorana magnetic moments of solar neutrinos by simultaneously fitting all the observed solar neutrino rates. The bounds the magnetic moment matrix elements are of the order of 10^{-10} Bohr magnetron.

  6. Resonant solar neutrino oscillation versus laboratory neutrino oscillation experiments

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Chong-Sa

    1987-02-01

    The interplay between resonant solar neutrino oscillations and neutrino oscillations in laboratory experiments is investigated in a 3 generation model. Due to the assumed hierarchy of neutrino masses, together with our choice of a convenient parameterization of the 3 generation mixing matrix, we can derive a simple analytic formula which reduces the solar neutrino problem to an effective 2 generation problem. The reduction makes it apparent that the allowed range of mixing and mass parameters crucially depend on whether the survival probability of solar neutrinos S satisfies S greater than or equal to 1/3 or not. The formulae for probabilities of laboratory neutrino oscillations are also greatly simplified. We argue that a combination of the observed solar neutrino depletion and data obtained from reactor experiments seems to rule out some range of neutrino masses. If a sizable nu/sub ..mu../ ..-->.. nu/sub e/ oscillation is observed at accelerators, as suggested at this Workshop, it severely restricts the range of 2 mixing angles.

  7. John Bahcall and the Solar Neutrino Problem

    Science.gov (United States)

    Bahcall, Neta

    2016-03-01

    ``I feel like dancing'', cheered John Bahcall upon hearing the exciting news from the SNO experiment in 2001. The results confirmed, with remarkable accuracy, John's 40-year effort to predict the rate of neutrinos from the Sun based on sophisticated Solar models. What began in 1962 by John Bahcall and Ray Davis as a pioneering project to test and confirm how the Sun shines, quickly turned into a four-decade-long mystery of the `Solar Neutrino Problem': John's models predicted a higher rate of neutrinos than detected by Davis and follow-up experiments. Was the theory of the Sun wrong? Were John's calculations in error? Were the neutrino experiments wrong? John worked tirelessly to understand the physics behind the Solar Neutrino Problem; he led the efforts to greatly increase the accurately of the solar model, to understand its seismology and neutrino fluxes, to use the neutrino fluxes as a test for new physics, and to advocate for important new experiments. It slowly became clear that none of the then discussed possibilities --- error in the Solar model or neutrino experiments --- was the culprit. The SNO results revealed that John's calculations, and hence the theory of the Solar model, have been correct all along. Comparison of the data with John's theory demanded new physics --- neutrino oscillations. The Solar Neutrino saga is one of the most amazing scientific stories of the century: exploring a simple question of `How the Sun Shines?' led to the discovery of new physics. John's theoretical calculations are an integral part of this journey; they provide the foundation for the Solar Neutrino Problem, for confirming how the Sun shines, and for the need of neutrino oscillations. His tenacious persistence, dedication, enthusiasm and love for the project, and his leadership and advocacy of neutrino physics over many decades are a remarkable story of scientific triumph. I know John is smiling today.

  8. Solar neutrinos, helioseismology and the solar internal dynamics

    CERN Document Server

    Turck-Chieze, S

    2010-01-01

    Neutrinos are fundamental particles ubiquitous in the Universe. Their properties remain elusive despite more than 50 years of intense research activity. In this review we remind the reader of the noticeable properties of these particles and of the stakes of the solar neutrino puzzle. The Standard Solar Model triggered persistent efforts in fundamental Physics to predict the solar neutrino fluxes, and its constantly evolving predictions have been regularly compared to the detected neutrino signals. Anticipating that this standard model could not reproduce the internal solar dynamics, a SEismic Solar Model was developed which enriched theoretical neutrino flux predictions with in situ observation of acoustic waves propagating in the Sun. This review reminds the historical steps, from the pioneering Homestake detection, the GALLEX- SAGE captures of the first pp neutrinos and emphasizes the importance of the Superkamiokande and SNO detectors to demonstrate that the solar-emitted electronic neutrinos are partially...

  9. Influence of solar flares on behavior of solar neutrino flux

    CERN Document Server

    Boyarkin, O M

    2016-01-01

    Limiting ourselves to two flavor approximation the motion of the neutrino flux in the solar matter and twisting magnetic field is considered. For the neutrino system described by the 4-component wave function $\\Psi^T = (\

  10. Low-energy (anti)neutrino physics with Borexino: Neutrinos from the primary proton-proton fusion process in the Sun

    CERN Document Server

    Mosteiro, P; Benziger, J; Bick, D; Bonfini, G; Bravo, D; Caccianiga, B; Cadonati, L; Calaprice, F; Caminata, A; Cavalcante, P; Chavarria, A; Chepurnov, A; D'Angelo, D; Davini, S; Derbin, A; Empl, A; Etenko, A; Fomenko, K; Franco, D; Gabriele, F; Galbiati, C; Gazzana, S; Ghiano, C; Giammarchi, M; Goeger-Neff, M; Goretti, A; Gromov, M; Hagner, C; Hungerford, E; Ianni, Al; Ianni, An; Kobychev, V; Korablev, D; Korga, G; Kryn, D; Laubenstein, M; Lehnert, B; Lewke, T; Litvinovich, E; Lombardi, F; Lombardi, P; Ludhova, L; Lukyanchenko, G; Machulin, I; Manecki, S; Maneschg, W; Marcocci, S; Meindl, Q; Meroni, E; Meyer, M; Miramonti, L; Misiaszek, M; Montuschi, M; Muratova, V; Oberauer, L; Obolensky, M; Ortica, F; Otis, K; Pallavicini, M; Papp, L; Perasso, L; Pocar, A; Ranucci, G; Razeto, A; Re, A; Romani, A; Rossi, N; Saldanha, R; Salvo, C; Schoenert, S; Simgen, H; Skorokhvatov, M; Smirnov, O; Sotnikov, A; Sukhotin, S; Suvorov, Y; Tartaglia, R; Testera, G; Vignaud, D; Vogelaar, R B; von Feilitzsch, F; Wang, H; Winter, J; Wojcik, M; Wright, A; Wurm, M; Zaimidoroga, O; Zavatarelli, S; Zuber, K; Zuzel, G

    2015-01-01

    The Sun is fueled by a series of nuclear reactions that produce the energy that makes it shine. The primary reaction is the fusion of two protons into a deuteron, a positron and a neutrino. These neutrinos constitute the vast majority of neutrinos reaching Earth, providing us with key information about what goes on at the core of our star. Several experiments have now confirmed the observation of neutrino oscillations by detecting neutrinos from secondary nuclear processes in the Sun; this is the first direct spectral measurement of the neutrinos from the keystone proton-proton fusion. This observation is a crucial step towards the completion of the spectroscopy of pp-chain neutrinos, as well as further validation of the LMA-MSW model of neutrino oscillations.

  11. Limits on CPT violation from solar neutrinos

    CERN Document Server

    Diaz, Jorge S

    2016-01-01

    Violations of CPT invariance can induce neutrino-to-antineutrino transitions. We study this effect for solar neutrinos and use the upper bound on the solar neutrino-to-antineutrino transition probability from the KamLAND experiment to constrain CPT-symmetry-violating coefficients of the general Standard-Model Extension. The long propagation distance from the Sun to the Earth allows us to improve existing limits by factors ranging from about a thousand to $10^{11}$.

  12. Low-energy neutrino measurements

    Indian Academy of Sciences (India)

    Davide D'angelo

    2012-10-01

    Low-energy solar neutrino detection plays a fundamental role in understanding both solar astrophysics and particle physics. After introducing the open questions on both fields, we review here the major results of the last two years and expectations for the near future from Borexino, Super-Kamiokande, SNO and KamLAND experiments as well as from upcoming (SNO+) and planned (LENA) experiments. Scintillator neutrino detectors are also powerful antineutrino detectors which can detect neutrinos emitted by the Earth crust and mantle. First measurements of geoneutrinos have occurred which can bring fundamental contribution in understanding the geophysics of the planet.

  13. GPS-based CERN-LNGS time link for Borexino

    CERN Document Server

    Caccianiga, B; Cerretto, G; Esteban, H; Korga, G; Misiaszek, M; Orsini, M; Pallavicini, M; Pettiti, V; Plantard, C; Razeto, A

    2012-01-01

    We describe the design, the equipment, and the calibration of a new GPS based time link between CERN and the Borexino experiment at the Gran Sasso Laboratory in Italy. This system has been installed and operated in Borexino since March 2012, and used for a precise measurement of CNGS muon neutrinos speed in May 2012. The result of the measurement will be reported in a different letter.

  14. Toward precision measurements in solar neutrinos

    CERN Document Server

    De Holanda, P C; Smirnov, A Yu; Liao, Wei

    2004-01-01

    Solar neutrino physics enters the stage of precision measurements. In this connection we present the precise analytic description of the neutrino conversion in the context of the LMA MSW solution of the solar neutrino problem. Using the adiabatic perturbation theory we find an analytic formula for the survival probability which takes into account the non-adiabatic corrections and the regeneration effect inside the Earth. The probability is averaged over the neutrino production region. We find that the non-adiabatic corrections are of the order $10^{-9}-10^{-7}$. Using the formula for the Earth regeneration effect we discuss features of the zenith angle dependence of the $\

  15. Four-Neutrino Oscillation Solutions of the Solar Neutrino Problem

    CERN Document Server

    Giunti, C; Peña-Garay, C

    2000-01-01

    We present an analysis of the neutrino oscillation solutions of the solar neutrino problem in the framework of four-neutrino mixing where a sterile neutrino is added to the three standard ones. We perform a fit to the full data set corresponding to the 825-day Super-Kamiokande data sample as well as to Chlorine, GALLEX and SAGE and Kamiokande experiments. In our analysis we use all measured total event rates as well as all Super-Kamiokande data on the zenith angle dependence and the recoil electron energy spectrum. We consider both transitions via the Mikheyev-Smirnov-Wolfenstein (MSW) mechanism as well as oscillations in vacuum (just-so) and find the allowed solutions for different values of the additional mixing angles. This framework permits transitions into active or sterile neutrinos controlled by the additional parameter $\\cos^2(\\vartheta_{23}) \\cos^2(\\vartheta_{24})$ . We discuss the maximum allowed values of this additional mixing parameter for the different solutions.

  16. Effect of solar electron temperature on pep solar neutrino flux in the chlorine solar neutrino experiment and the gallium solar neutrino experiment

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The rate of the electron-capture reaction of proton,p+e-+p→2H+ve , is calculated considering the temperature of solar electron in the solar center instead of that of solar ion. When the solar electron temperature is two times higher than the solar ion temperature in the solar center, the capture rate pep solar neutrino predicted by the standard solar model (SSM) is decreased to (0.16±0.01) SNU from (0.22±0.01) SNU in the chlorine solar neutrino experiment, and decreased to 2.19 SNU from 3.0 SNU in the gallium solar neutrino experiment.

  17. MSW mediated neutrino decay and the solar neutrino problem

    CERN Document Server

    Bandyopadhyay, A; Goswami, S; Choubey, Sandhya; Goswami, Srubabati

    2001-01-01

    We investigate the solar neutrino problem assuming simultaneous presence of MSW transitions in the sun and neutrino decay on the way from sun to earth. We do a global $\\chi^2$-analysis of the data on total rates in Cl, Ga and Superkamiokande (SK) experiments and the SK day-night spectrum data and determine the changes in the allowed region in the $\\dm - \\tan^2\\theta$ plane in presence of decay. We also discuss the implications for unstable neutrinos in the SNO experiment.

  18. Solar Neutrino Oscillation Parameters in Experiments with Reactor Anti-Neutrinos

    CERN Document Server

    Choubey, Sandhya

    2004-01-01

    We review the current status of the solar neutrino oscillation parameters. We discuss the conditions under which measurements from future solar neutrino experiments would determine the oscillation parameters precisely. Finally we expound the potential of long baseline reactor anti-neutrino experiments in measuring the solar neutrino oscillation parameters.

  19. Solar Neutrino Observables Sensitive to Matter Effects

    Directory of Open Access Journals (Sweden)

    H. Minakata

    2012-01-01

    Full Text Available We discuss constraints on the coefficient AMSW which is introduced to simulate the effect of weaker or stronger matter potential for electron neutrinos with the current and future solar neutrino data. The currently available solar neutrino data leads to a bound AMSW=1.47+0.54−0.42(+1.88−0.82 at 1σ (3σ CL, which is consistent with the Standard Model prediction AMSW=1. For weaker matter potential (AMSW1, the bound is milder and is dominated by the day-night asymmetry of 8B neutrino flux recently observed by Super-Kamiokande. Among the list of observables of ongoing and future solar neutrino experiments, we find that (1 an improved precision of the day-night asymmetry of 8B neutrinos, (2 precision measurements of the low-energy quasi-monoenergetic neutrinos, and (3 the detection of the upturn of the 8B neutrino spectrum at low energies are the best choices to improve the bound on AMSW.

  20. Updated determination of the solar neutrino fluxes from solar neutrino data

    CERN Document Server

    Bergstrom, Johannes; Maltoni, Michele; Pena-Garay, Carlos; Serenelli, Aldo M; Song, Ningqiang

    2016-01-01

    We present an update of the determination of the solar neutrino fluxes from a global analysis of the solar and terrestrial neutrino data in the framework of three-neutrino mixing. Using a Bayesian analysis we reconstruct the posterior probability distribution function for the eight normalization parameters of the solar neutrino fluxes plus the relevant masses and mixing, with and without imposing the luminosity constraint. We then use these results to compare the description provided by different Standard Solar Models. Our results show that, at present, both models with low and high metallicity can describe the data with equivalent statistical agreement. We also argue that even with the present experimental precision the solar neutrino data have the potential to improve the accuracy of the solar model predictions.

  1. More solar models and neutrino fluxes.

    Science.gov (United States)

    Abraham, Z.; Iben, I., Jr.

    1971-01-01

    Derivation of neutrino fluxes from a sequence of solar models that differ from one another in regard to opacity, equation of state, and nuclear cross-section factors. Using current estimates of the relevant input parameters, capture rates are obtained that range between three and ten times the most recent result of the Davis Cl 37 neutrino-capture experiment. The contribution to a theoretical capture rate due to neutrinos from all reactions other than B 8 decay ranges from 0.5 to 1.5 times the latest observational result. Comparison with results of other solar model calculations indicates reasonable agreement when results are normalized to the same input parameters.

  2. Large extra dimensions, sterile neutrinos and solar neutrino data.

    Science.gov (United States)

    Caldwell, D O; Mohapatra, R N; Yellin, S J

    2001-07-23

    Solar, atmospheric, and LSND neutrino oscillation results require a light sterile neutrino, nu(B), which can exist in the bulk of extra dimensions. Solar nu(e), confined to the brane, can oscillate in the vacuum to the zero mode of nu(B) and via successive Mikheyev-Smirnov-Wolfenstein transitions to Kaluza-Klein states of nu(B). This new way to fit solar data is provided by both low and intermediate string scale models. From average rates seen in the three types of solar experiments, the Super-Kamiokande spectrum is predicted with 73% probability, but dips characteristic of the 0.06 mm extra dimension should be seen in the SNO spectrum.

  3. Updating neutrino magnetic moment constraints

    CERN Document Server

    Canas, B C; Parada, A; Tortola, M; Valle, J W F

    2015-01-01

    In this paper we provide an updated analysis of the neutrino magnetic moments (NMMs), discussing both the constraints on the magnitudes of the three transition moments Lambda_i as well as the role of the CP violating phases present both in the mixing matrix and in the NMM matrix. The scattering of solar neutrinos off electrons in Borexino provides the most stringent restrictions, due to its robust statistics and the low energies observed, below 1 MeV. Our new limit on the effective neutrino magnetic moment which follows from the most recent Borexino data is 3.1 x 10^-11 mu_B at 90% C.L. This corresponds to the individual transition magnetic moment constraints: |Lambda_1| < 5.6 x10^-11 mu_B, |Lambda_2| < 4.0 x 10^-11 mu_B, and |Lambda_3| < 3.1 x 10^-11 mu_B (90% C.L.), irrespective of any complex phase. Indeed, the incoherent admixture of neutrino mass eigenstates present in the solar flux makes Borexino insensitive to the Majorana phases present in the NMM matrix. For this reason we also provide a gl...

  4. Solar neutrino analysis of Super-Kamiokande

    CERN Document Server

    Sekiya, Hiroyuki

    2013-01-01

    Super-Kamiokande-IV data taking began in September of 2008, and with upgraded electronics and improvements to water system dynamics, calibration and analysis techniques, a clear solar neutrino signal could be extracted at recoil electron kinetic energies as low as 3.5 MeV. The SK-IV extracted solar neutrino flux between 3.5 and 19.5 MeV is found to be (2.36$\\pm$0.02(stat.)$\\pm$0.04(syst.))$\\times 10^6$ /(cm$^2$sec). The SK combined recoil electron energy spectrum favors distortions predicted by standard neutrino flavour oscillation parameters over a flat suppression at 1$\\sigma$ level. A maximum likelihood fit to the amplitude of the expected solar zenith angle variation of the elastic neutrino-electron scattering rate in SK, results in a day/night asymmetry of $-3.2\\pm1.1$(stat.)$\\pm$0.5(syst.)$%$. The 2.7 $\\sigma$ significance of non-zero asymmetry is the first indication of the regeneration of electron type solar neutrinos as they travel through Earth's matter. A fit to all solar neutrino data and KamLAND ...

  5. Influence of solar flares on behavior of solar neutrino flux

    Science.gov (United States)

    Boyarkin, O. M.; Boyarkina, G. G.

    2016-12-01

    Limiting ourselves to two flavor approximation the motion of the neutrino flux in the solar matter and twisting magnetic field is considered. For the neutrino system described by the 4-component wave function ΨT =(νeL ,νXL ,νbareL ,νbarXL) , where X = μ , τ , an evolution equation is found. Our consideration carries general character, that is, it holds for any SM extensions with massive neutrinos. The resonance transitions of the electron neutrinos are investigated. Factors which influence on the electron neutrino flux, crossing a region of solar flares (SF) are defined. When the SF is absent a terrestrial detector records the electron neutrino flux weakened at the cost both of vacuum oscillations and of the MSW resonance conversion only. On the other hand, the electron neutrino flux passed the SF region in preflare period proves to be further weakened in so far as it undergoes one (Majorana neutrino) or two (Dirac neutrino) additional resonance conversions, apart from the MSW resonance and vacuum oscillations. The hypothesis of the νe-induced decays which states that decreasing the beta decay rates of some elements of the periodic table is caused by reduction of the solar neutrino flux is discussed as well.

  6. Solar and Supernova Constraints on Cosmologically Interesting Neutrinos

    CERN Document Server

    Haxton, W

    1997-01-01

    The sun and core-collapse supernovae produce neutrino spectra that are sensitive to the effects of masses and mixing. Current results from solar neutrino experiments provide perhaps our best evidence for such new neutrino physics, beyond the standard electroweak model. I discuss this evidence as well as the limited possibilities for more conventional explanations. If the resolution of the solar neutrino problem is $\

  7. Solar models, neutrino experiments, and helioseismology

    Science.gov (United States)

    Bahcall, John N.; Ulrich, Roger K.

    1988-01-01

    The event rates and their recognized uncertainties are calculated for 11 solar neutrino experiments using accurate solar models. These models are also used to evaluate the frequency spectrum of the p and g oscillations modes of the sun. It is shown that the discrepancy between the predicted and observed event rates in the Cl-37 and Kamiokande II experiments cannot be explained by a 'likely' fluctuation in input parameters with the best estimates and uncertainties given in the present study. It is suggested that, whatever the correct solution to the solar neutrino problem, it is unlikely to be a 'trival' error.

  8. Solar neutrinos, solar flares, solar activity cycle and the proton decay

    Science.gov (United States)

    Raychaudhuri, P.

    1985-01-01

    It is shown that there may be a correlation between the galactic cosmic rays and the solar neutrino data, but it appears that the neutrino flux which may be generated during the large solar cosmic ray events cannot in any way effect the solar neutrino data in Davis experiment. Only initial stage of mixing between the solar core and solar outer layers after the sunspot maximum in the solar activity cycle can explain the higher (run number 27 and 71) of solar neutrino data in Davis experiment. But solar flare induced atmospheric neutrino flux may have effect in the nucleon decay detector on the underground. The neutrino flux from solar cosmic rays may be a useful guide to understand the background of nucleon decay, magnetic monopole search, and the detection of neutrino flux in sea water experiment.

  9. Solar Neutrino Results from Super-Kamiokande

    CERN Document Server

    Renshaw, Andrew

    2015-01-01

    Super-Kamiokande-IV (SK-IV) data taking began in September of 2008, after upgrading the electronics and data acquisition system. Due to these upgrades and improvements to water system dynamics, calibration and analysis techniques, a solar neutrino signal could be extracted at recoil electron kinetic energies as low as 3.5 MeV. When the SK-IV data is combined with the previous three SK phases, the SK extracted solar neutrino flux is found to be $[2.37\\pm0.015\\mbox{(stat.)}\\pm0.04\\mbox{(syst.)}]\\times10^6$/(cm$^{2}$sec). The combination of the SK recoil electron energy spectra slightly favors distortions due to a changing electron flavor content. Such distortions are predicted when assuming standard solar neutrino oscillation solutions. An extended maximum likelihood fit to the amplitude of the expected solar zenith angle variation of the neutrino-electron elastic scattering rate results in a day-night asymmetry of $[-3.2\\pm1.1$(stat.)$\\pm0.5$(syst.)]$\\%$. A solar neutrino global oscillation analysis including ...

  10. Linking solar and long baseline terrestrial neutrino experiments.

    Science.gov (United States)

    Akhmedov, E K; Branco, G C; Rebelo, M N

    2000-04-17

    We show that, in the framework of three light neutrino species with hierarchical masses and assuming no fine tuning between the entries of the neutrino mass matrix, one can use the solar neutrino data to obtain information on the element U(e3) of the lepton mixing matrix. Conversely, a measurement of U(e3) in atmospheric or long baseline accelerator or reactor neutrino experiments would help discriminate between possible oscillation solutions of the solar neutrino problem.

  11. Solar Neutrino Measurement at SK-III

    CERN Document Server

    Yang, B S

    2009-01-01

    The full Super-Kamiokande-III data-taking period, which ran from August of 2006 through August of 2008, yielded 298 live days worth of solar neutrino data with a lower total energy threshold of 4.5 MeV. During this period we made many improvements to the experiment's hardware and software, with particular emphasis on its water purification system and Monte Carlo simulations. As a result of these efforts, we have significantly reduced the low energy backgrounds as compared to earlier periods of detector operation, cut the systematic errors by nearly a factor of two, and achieved a 4.5 MeV energy threshold for the solar neutrino analysis. In this presentation, I will present the preliminary SK-III solar neutrino measurement results.

  12. A Monte Carlo approach to Beryllium-7 solar neutrino analysis with KamLAND

    Science.gov (United States)

    Grant, Christopher Peter

    hypothesis and the existence of the 7Be solar neutrino signal in the data shows a change of 27.9 units, providing evidence that the signal is statistically favored. This analysis reports a measured interaction rate from 7Be solar neutrinos of R = 343.3 +/- 65.0(stat) +/- 99.2(syst) events/(kton·day), which corresponds to a total flux of phi = (3.41 +/- 1.18) x 109 cm-2s-1. The 7Be solar neutrino flux reported in this work is only the second measurement made of this quantity worldwide. It provides an important cross-check of the Borexino experiment. The flux measurement reported here agrees within 1sigma with the standard solar model predictions thus validating our basic understanding of solar fusion reaction processes.

  13. Solar Model Parameters and Direct Measurements of Solar Neutrino Fluxes

    CERN Document Server

    Bandyopadhyay, A; Goswami, S; Petcov, S T; Bandyopadhyay, Abhijit; Choubey, Sandhya; Goswami, Srubabati

    2006-01-01

    We explore a novel possibility of determining the solar model parameters, which serve as input in the calculations of the solar neutrino fluxes, by exploiting the data from direct measurements of the fluxes. More specifically, we use the rather precise value of the $^8B$ neutrino flux, $\\phi_B$ obtained from the global analysis of the solar neutrino and KamLAND data, to derive constraints on each of the solar model parameters on which $\\phi_B$ depends. We also use more precise values of $^7Be$ and $pp$ fluxes as can be obtained from future prospective data and discuss whether such measurements can help in reducing the uncertainties of one or more input parameters of the Standard Solar Model.

  14. Solar neutrino problem and gravitationally induced long-wavelength neutrino oscillation

    Science.gov (United States)

    Gago; Nunokawa; Zukanovich Funchal R

    2000-05-01

    We have reexamined the possibility of explaining the solar neutrino data through long-wavelength neutrino oscillations induced by a tiny breakdown of the weak equivalence principle of general relativity. We have found that such gravitationally induced oscillations can provide a viable solution to the solar neutrino problem.

  15. SNO and the solar neutrino problem

    CERN Document Server

    Choubey, S; Goswami, S; Roy, D P; Choubey, Sandhya; Bandyopadhyay, Abhijit; Goswami, Srubabati

    2002-01-01

    We study the implication of the first neutral current (NC) data from SNO. We perform model independent and model dependent analyses of the solar neutrino data. The inclusion of the first SNO NC data in the model independent analysis determines the allowed ranges of $^{8}{B}$ flux normalization and the $\

  16. Resolution of the solar neutrino anomaly

    CERN Document Server

    Dubin, M; Dubin, Maurice; Soberman, Robert K

    1996-01-01

    The solar neutrino anomaly, measurements discrepant from predictions of the Standard Solar Model, has existed for over 30 years. Multiple experiments measuring fluxes from several reactions in the hydrogen fusion chain have added to the puzzle. Each of the several elements of the enigma are resolved by recognition of measurements establishing that most of the sun's fusion must occur near the surface rather than the core.

  17. Updated solution to the solar neutrino problem based on non-standard neutrino interactions

    CERN Document Server

    Guzzo, M M; Nunokawa, H

    2001-01-01

    We present an updated version of the solution to the solar neutrino problem based on non-standard flavor changing neutrino interactions (FCNI) and non-universal flavor diagonal neutrino interactions (FDNI). We find a good fit not only to the total rates measured by all solar neutrino experiments but also to the day-night and seasonal variations of the event rate, as well as the recoil electron energy spectrum measured by the SuperKamiokande collaboration.

  18. Solar cosmic ray bursts and solar neutrino fluxes

    Science.gov (United States)

    Basilevakaya, G. A.; Nikolsky, S. I.; Stozhkov, Y. I.; Charakhchyan, T. N.

    1985-01-01

    The neutrino flux detected in the C1-Ar experiment seems to respond to the powerful solar cosmic ray bursts. The ground-based detectors, the balloons and the satellites detect about 50% of the bursts of soalr cosmic ray generated on the Sun's visible side. As a rule, such bursts originate from the Western side of the visible solar disk. Since the solar cosmic ray bursts are in opposite phase withthe 11-year galactic cosmic ray cycle which also seems to be reflected by neutrino experiment. The neutrino generation in the bursts will flatten the possible 11-year behavior of the AR-37 production rate, Q, in the Cl-Ar experiment. The detection of solar-flare-generated gamma-quanta with energies above tens of Mev is indicative of the generation of high-energy particles which in turn may produce neutrinos. Thus, the increased Q during the runs, when the flare-generated high energy gamma-quanta have been registered, may be regarded as additional evidence for neutrino geneation in the solar flare processes.

  19. Neutrino production from the solar atmosphere

    Science.gov (United States)

    Inazawa, H.; Kobayakawa, K.; Kitamura, T.

    1985-01-01

    When the high energy primary cosmic rays enter near the solar surface, they pass through a thick matter but having a low density. If the density and path length satisfy an appropriate condition, the primaries collide with the constituents near the solar sphere (almost protons) and produce pions and kaons, most of which decay into mu plus nu sub mu without successive hadron collisions. Muons also decay into NU sub mu and NU sub e before reaching the Earth. The neutrino flux of which the producer is matter near the solar surface is computed by solving cascade diffusion equations. The calculated differential flux of muon neutrino at 1 TeV is 1 X 10 to the minus 13 power (GeV. cm square centimeters 2.s.ster)(-1) which is rather difficult to be observed in the present apparatuses or DUMAND.

  20. Computation of 7Be solar neutrino flux

    Institute of Scientific and Technical Information of China (English)

    YE Zipiao; SHENG Xiangdong; DAI Changjiang

    2003-01-01

    Within the target range from 0 to 0.1217 times the solar radius, the probability of 7Be existing as an ion with one or two bound electrons is calculated, which is turned out to be about 4.69 %, and about 95.3 1 % 7Be nucleus is completely ionized. After considering the influence of that portion of incompletely ionized 7Be, the renewly calculative result shows that the solar neutrino flux of 7Be will decrease from 45 000 m-2.s-1 to 43 000 m-2.s-1, and the predicted value of the 8B solar neutrino flux will increase from 51 5 m-2.s-1 to 535 m-2.s-1.

  1. Low Background Techniques And Experimental Challenges For Borexino And Its Nylon Vessels

    CERN Document Server

    Pocar, A P

    2003-01-01

    Borexino is an experiment for low energy (<1 MeV) solar neutrino spectroscopy approaching completion at the underground Gran Sasso laboratories in Italy. It is specifically designed to measure in real time the flux of mono-energetic [/berillium] neutrinos produced by fusion reactions in the Sun. Its 300-ton liquid scintillator target is contained in an 8.5 meter diameter nylon inner vessel (IV) and is surrounded by 1000 tons of buffer fluid. A second, 11.5 meter diameter concentric nylon outer vessel (OV) around the IV serves as a barrier for radon emanated at the periphery of the detector. Borexino requires unprecedented low levels of radioactive impurities to be a success (∼1 background event/day in the central 100-tons of scintillator). The IV, which is in direct contact with the scintillator, also has to meet extremely stringent radioactive and cleanliness requirements. Intrinsic levels ∼10 −12 g/g for U and Th and ∼10−8 g/g for K are needed. The vessels,...

  2. Report of the Solar and Atmospheric Neutrino Working Group

    Energy Technology Data Exchange (ETDEWEB)

    Back, H.; Bahcall, J.N.; Bernabeu, J.; Boulay, M.G.; Bowles, T.; Calaprice, F.; Champagne, A.; Freedman, S.; Gai, M.; Galbiati, C.; Gallagher, H.; Gonzalez-Garcia, C.; Hahn, R.L.; Heeger, K.M.; Hime, A.; Jung, C.K.; Klein, J.R.; Koike, M.; Lanou, R.; Learned, J.G.; Lesko, K.T.; Losecco, J.; Maltoni, M.; Mann, A.; McKinsey, D.; Palomares-Ruiz, S.; Pena-Garay, C.; Petcov, S.T.; Piepke, A.; Pitt, M.; Raghavan, R.; Robertson, R.G.H.; Scholberg, K.; Sobel, H.W.; Takeuchi, T.; Vogelaar, R.; Wolfenstein, L.

    2004-10-22

    The highest priority of the Solar and Atmospheric Neutrino Experiment Working Group is the development of a real-time, precision experiment that measures the pp solar neutrino flux. A measurement of the pp solar neutrino flux, in comparison with the existing precision measurements of the high energy {sup 8}B neutrino flux, will demonstrate the transition between vacuum and matter-dominated oscillations, thereby quantitatively testing a fundamental prediction of the standard scenario of neutrino flavor transformation. The initial solar neutrino beam is pure {nu}{sub e}, which also permits sensitive tests for sterile neutrinos. The pp experiment will also permit a significantly improved determination of {theta}{sub 12} and, together with other solar neutrino measurements, either a measurement of {theta}{sub 13} or a constraint a factor of two lower than existing bounds. In combination with the essential pre-requisite experiments that will measure the {sup 7}Be solar neutrino flux with a precision of 5%, a measurement of the pp solar neutrino flux will constitute a sensitive test for non-standard energy generation mechanisms within the Sun. The Standard Solar Model predicts that the pp and {sup 7}Be neutrinos together constitute more than 98% of the solar neutrino flux. The comparison of the solar luminosity measured via neutrinos to that measured via photons will test for any unknown energy generation mechanisms within the nearest star. A precise measurement of the pp neutrino flux (predicted to be 92% of the total flux) will also test stringently the theory of stellar evolution since the Standard Solar Model predicts the pp flux with a theoretical uncertainty of 1%. We also find that an atmospheric neutrino experiment capable of resolving the mass hierarchy is a high priority. Atmospheric neutrino experiments may be the only alternative to very long baseline accelerator experiments as a way of resolving this fundamental question. Such an experiment could be a very

  3. GNO Solar Neutrino Observations: Results for GNOI

    OpenAIRE

    GNO Collaboration; Altmann, M; Balata, M.; Belli, P.; Bellotti, E.(Dipartimento di Fisica, Università Milano Bicocca, Milan, Italy); Bernabei, R.; Burkert, E; Cattadori, C.; Cerichelli, G.; Chiarini, M; Cribier, M.; D'Angelo, S; Del Re, G.; Ebert, K.H.; Feilitzsch, F. v.

    2000-01-01

    We report the first GNO solar neutrino results for the measuring period GNOI, solar exposure time May 20, 1998 till January 12, 2000. In the present analysis, counting results for solar runs SR1 - SR19 were used till April 4, 2000. With counting completed for all but the last 3 runs (SR17 - SR19), the GNO I result is [65.8 +10.2 -9.6 (stat.) +3.4 -3.6 (syst.)]SNU (1sigma) or [65.8 + 10.7 -10.2 (incl. syst.)]SNU (1sigma) with errors combined. This may be compared to the result for Gallex(I-IV)...

  4. Solar neutrino physics in the nineties

    Energy Technology Data Exchange (ETDEWEB)

    Wilkerson, J.F.

    1990-12-31

    The decade of the 1990`s should prove to be landmark period for the study of solar neutrino physics. Current observations show 2--3 times fewer neutrinos coming from the sun than are theoretically expected. As we enter the decade, new experiments are poised to attempt and discover whether this deficit is a problem with our understanding of how the sun works, is a hint of new neutrino properties beyond those predicted by the standard model of particle physics, or perhaps a combination of both. This paper will briefly review the current status of the field and point out how future measurements should help solve this interesting puzzle. 11 refs., 3 figs., 1 tab.

  5. Monte Carlo exploration of Mikheyev-Smirnov-Wolfenstein solutions to the solar neutrino problem

    Science.gov (United States)

    Shi, X.; Schramm, D. N.; Bahcall, J. N.

    1992-01-01

    The paper explores the impact of astrophysical uncertainties on the Mikheyev-Smirnov-Wolfenstein (MSW) solution by calculating the allowed MSW solutions for 1000 different solar models with a Monte Carlo selection of solar model input parameters, assuming a full three-family MSW mixing. Applications are made to the chlorine, gallium, Kamiokande, and Borexino experiments. The initial GALLEX result limits the mixing parameters to the upper diagonal and the vertical regions of the MSW triangle. The expected event rates in the Borexino experiment are also calculated, assuming the MSW solutions implied by GALLEX.

  6. Solar Neutrino flare detection in Hyperkamiokande and SK

    Science.gov (United States)

    Fargion, Daniele

    2016-07-01

    The possible buid and near activity of a Megaton neutrino detection in HyperKamiokande and the older SK implementation by Gadolinium liqid might open to future detection of largest solar flare (pion trace at tens MeV) electron neutrino and antineutrino. The multiwave detection of X-gamma and neutrino event might offer a deep view of such solar acelleration and of neutrino flavor mix along its flight. The possoble near future discover of such events will open a third neutrino astronomy windows after rarest SN 1987A and persistent Solar nuclear signals.

  7. Alive and well: a short review about standard solar models

    CERN Document Server

    Serenelli, Aldo

    2016-01-01

    Standard solar models (SSMs) provide a reference framework across a number of research fields: solar and stellar models, solar neutrinos, particle physics the most conspicuous among them. The accuracy of the physical description of the global properties of the Sun that SSMs provide has been challenged in the last decade by a number of developments in stellar spectroscopic techniques. Over the same period of time, solar neutrino experiments, and Borexino in particular, have measured the four solar neutrino fluxes from the pp-chains that are associated with 99\\% of the nuclear energy generated in the Sun. Borexino has also set the most stringent limit on CNO energy generation, only $\\sim 40\\%$ larger than predicted by SSMs. More recently, and for the first time, radiative opacity experiments have been performed at conditions that closely resemble those at the base of the solar convective envelope. In this article, we review these developments and discuss the current status of SSMs, including its intrinsic limit...

  8. Alive and well: A short review about standard solar models

    Energy Technology Data Exchange (ETDEWEB)

    Serenelli, Aldo [Campus UAB, Carrer de Can Magrans S/N, Instituto de Ciencias del Espacio (ICE/CSIC-IEEC), Cerdanyola del Valles (Spain)

    2016-04-15

    Standard solar models (SSMs) provide a reference framework across a number of research fields: solar and stellar models, solar neutrinos, particle physics the most conspicuous among them. The accuracy of the physical description of the global properties of the Sun that SSMs provide has been challenged in the last decade by a number of developments in stellar spectroscopic techniques. Over the same period of time, solar neutrino experiments, and Borexino in particular, have measured the four solar neutrino fluxes from the pp-chains that are associated with 99% of the nuclear energy generated in the Sun. Borexino has also set the most stringent limit on CNO energy generation, only ∝ 40% larger than predicted by SSMs. More recently, and for the first time, radiative opacity experiments have been performed at conditions that closely resemble those at the base of the solar convective envelope. In this article, we review these developments and discuss the current status of SSMs, including its intrinsic limitations. (orig.)

  9. Correlation between solar neutrino flux and other solar phenomena

    Science.gov (United States)

    Lal, S.; Subramanian, A.

    1985-01-01

    A study was made of the solar neutrino data with a tank of CC14 located 4800 mwe underground for the period 1970 to 83. These observations are on the production rates of Ar37 atoms via the reaction upsilon sub e + Cl37 yields Ar37 plus e(-) in the tank caused presumably by a flux of neutrinos from the Sun. The idea of possible time variations in the data shown is discussed and an attempt is made to correlate the variations to two other phenomena of solar origin-the sunspot number and the geomagnetic Ap index.

  10. Dark matter, neutrinos, and our solar system

    CERN Document Server

    Prakash, Nirmala

    2013-01-01

    Dark Matter, Neutrinos, and Our Solar System is a unique enterprise that should be viewed as an important contribution to our understanding of dark matter, neutrinos and the solar system. It describes these issues in terms of links, between cosmology, particle and nuclear physics, as well as between cosmology, atmospheric and terrestrial physics. It studies the constituents of dark matter (classified as hot warm and cold) first in terms of their individual structures (baryonic and non-baryonic, massive and non-massive, interacting and non-interacting) and second, in terms of facilities available to detect these structures (large and small). Neutrinos (an important component of dark matter) are treated as a separate entity. A detailed study of these elusive (sub-atomic) particles is done, from the year 1913 when they were found as byproducts of beta decay -- until the discovery in 2007 which confirmed that neutrino flavors were not more than three (as speculated by some). The last chapter of the book details t...

  11. Report on the Brookhaven Solar Neutrino Experiment

    Science.gov (United States)

    Davis, R. Jr.; Evans, J. C. Jr.

    1976-09-22

    This report is intended as a brief statement of the recent developments and results of the Brookhaven Solar Neutrino Experiment communicated through Professor G. Kocharov to the Leningrad conference on active processes on the sun and the solar neutrino problem. The report summarizes the results of experiments performed over a period of 6 years, from April 1970 to January 1976. Neutrino detection depends upon the neutrino capture reaction /sup 37/Cl(..nu..,e/sup -/)/sup 37/Ar producing the isotope /sup 37/Ar (half life of 35 days). The detector contains 3.8 x 10/sup 5/ liters of C/sub 2/Cl/sub 4/ (2.2 x 10/sup 30/ atoms of /sup 37/Cl) and is located at a depth of 4400 meters of water equivalent (m.w.e.) in the Homestake Gold Mine at Lead, South Dakota, U.S.A. The procedures for extracting /sup 37/Ar and the counting techniques used were described in previous reports. The entire recovered argon sample was counted in a small gas proportional counter. Argon-37 decay events were characterized by the energy of the Auger electrons emitted following the electron capture decay and by the rise-time of the pulse. Counting measurements were continued for a period sufficiently long to observe the decay of /sup 37/Ar.

  12. The solar neutrino problem: Mixing of neutrinos and mixing in the sun

    Science.gov (United States)

    Haxton, W. C.

    I review the current status of the solar neutrino problem, including the exciting possibility of matter enhanced neutrino oscillations. Neutrino flux measurements, independent of questions of solar dynamics, appear to leave only one competing candidate astrophysical solution, at least in the case of steady-state solar models. That possibility - mixing of the solar core on time scales of 3He equilibration - appears to have some attractive features. A “score card” is presented in which the two alternatives - mixed neutrinos or a mixed sun - are handicapped.

  13. A 17 keV neutrino and large magnetic moment solution of the solar neutrino puzzle

    Science.gov (United States)

    Akhmedov, E. Kh.; Senjanovic, G.; Tao, Zhijian; Berezhiani, Z. G.

    1992-08-01

    Zee-type models with Majorons naturally incorporate the 17 keV neutrino but in their minimal version fail to simultaneously solve the solar neutrino puzzle. If there is a sterile neutrino state, a particularly simple solution is found to the solar neutrino problem, which besides nu(sub 17) predicts a light Zeldovich-Konopinski-Mahmoud neutrino nu(sub light) = nu(sub e) + nu(sub mu)(sup c) with a magnetic moment being easily as large as 10(exp -11)(mu)(sub B) through the Barr-Freire-Zee mechanism.

  14. 17 keV neutrino and large magnetic moment solution of the solar neutrino puzzle

    Science.gov (United States)

    Akhmedov, Eugeni Kh.; Berezhiani, Zurab G.; Senjanović, Goran; Tao, Zhijian

    1993-01-01

    Zee-type models with majorons naturally incorporate the 17 keV neutrino but in their minimal version fail to simultaneously solve the solar neutrino puzzle. If there is a sterile neutrino state, we find a particularly simple solution to the solar neutrino problem, which besides ν17 predicts a light Zeldovich-Konopinski-Mahmoud neutrino νlight = νe + νcμ with a magnetic moment being easily as large as 10 -11μB through the Barr-Freire-Zee mechanism.

  15. Constraints on Neutrino Oscillations Using 1258 Days of Super-Kamiokande Solar Neutrino Data

    CERN Document Server

    Fukuda, S; Ishitsuka, M; Itow, Y; Kajita, T; Kameda, J; Kaneyuki, K; Kobayashi, K; Koshio, Y; Miura, M; Moriyama, S; Nakahata, M; Nakayama, S; Okada, A; Sakurai, N; Shiozawa, M; Suzuki, Y; Takeuchi, H; Takeuchi, Y; Toshito, T; Totsuka, Y; Yamada, S; Desai, S V; Earl, M A; Kearns, E T; Messier, M D; Scholberg, K; Stone, J L; Sulak, Lawrence R; Walter, C W; Goldhaber, M; Barszczak, T; Casper, David William; Gajewski, W; Kropp, W R; Mine, S; Liu, D; Price, L R; Smy, M B; Sobel, H W; Vagins, M R; Ganezer, K S; Keig, W E; Ellsworth, R W; Tasaka, S; Kibayashi, A; Learned, J G; Matsuno, S; Takemori, D; Hayato, Y; Ishii, T; Kobayashi, T; Nakamura, K; Obayashi, Y; Oyama, Y; Sakai, A; Sakuda, M; Kohama, M; Suzuki, A T; Inagaki, T; Nakaya, T; Nishikawa, K; Haines, T J; Blaufuss, E; Dazeley, S A; Lee, K B; Svoboda, R; Chen, M L; Goodman, J A; Guillian, G; Sullivan, G W; Turcan, D; Habig, A; Hill, J; Jung, C K; Martens, K; Malek, M; Mauger, C; McGrew, C; Sharkey, E; Viren, B M; Yanagisawa, C; Mitsuda, C; Miyano, K; Saji, C; Shibata, T; Kajiyama, Y; Nagashima, Y; Nitta, K; Takita, M; Yoshida, M; Kim, H I; Kim, S B; Yoo, J; Okazawa, H; Ishizuka, T; Etoh, M; Gando, Y; Hasegawa, T; Inoue, K; Ishihara, K; Maruyama, T; Shirai, J; Suzuki, A; Koshiba, M; Hatakeyama, Y; Ichikawa, Y; Koike, M; Nishijima, K; Fujiyasu, H; Ishino, H; Morii, M; Watanabe, Y; Golebiewska, U; Kielczewska, D; Boyd, S C; Stachyra, A L; Wilkes, R J; Young, K K

    2001-01-01

    We report the result of a search for neutrino oscillations using precise measurements of the recoil electron energy spectrum and zenith angle variations of the solar neutrino flux from 1258 days of neutrino-electron scattering data in Super-Kamiokande. The absence of significant zenith angle variation and spectrum distortion places strong constraints on neutrino mixing and mass difference in a flux-independent way. Using the Super-Kamiokande flux measurement in addition, two allowed regions at large mixing are found.

  16. Constraints on neutrino oscillations using 1258 days of Super-Kamiokande solar neutrino data.

    Science.gov (United States)

    Fukuda, S; Fukuda, Y; Ishitsuka, M; Itow, Y; Kajita, T; Kameda, J; Kaneyuki, K; Kobayashi, K; Koshio, Y; Miura, M; Moriyama, S; Nakahata, M; Nakayama, S; Okada, A; Sakurai, N; Shiozawa, M; Suzuki, Y; Takeuchi, H; Takeuchi, Y; Toshito, T; Totsuka, Y; Yamada, S; Desai, S; Earl, M; Kearns, E; Messier, M D; Scholberg, K; Stone, J L; Sulak, L R; Walter, C W; Goldhaber, M; Barszczak, T; Casper, D; Gajewski, W; Kropp, W R; Mine, S; Liu, D W; Price, L R; Smy, M B; Sobel, H W; Vagins, M R; Ganezer, K S; Keig, W E; Ellsworth, R W; Tasaka, S; Kibayashi, A; Learned, J G; Matsuno, S; Takemori, D; Hayato, Y; Ishii, T; Kobayashi, T; Nakamura, K; Obayashi, Y; Oyama, Y; Sakai, A; Sakuda, M; Kohama, M; Suzuki, A T; Inagaki, T; Nakaya, T; Nishikawa, K; Haines, T J; Blaufuss, E; Dazeley, S; Lee, K B; Svoboda, R; Goodman, J A; Guillian, G; Sullivan, G W; Turcan, D; Habig, A; Hill, J; Jung, C K; Martens, K; Malek, M; Mauger, C; McGrew, C; Sharkey, E; Viren, B; Yanagisawa, C; Mitsuda, C; Miyano, K; Saji, C; Shibata, T; Kajiyama, Y; Nagashima, Y; Nitta, K; Takita, M; Yoshida, M; Kim, H I; Kim, S B; Yoo, J; Okazawa, H; Ishizuka, T; Etoh, M; Gando, Y; Hasegawa, T; Inoue, K; Ishihara, K; Maruyama, T; Shirai, J; Suzuki, A; Koshiba, M; Hatakeyama, Y; Ichikawa, Y; Koike, M; Nishijima, K; Fujiyasu, H; Ishino, H; Morii, M; Watanabe, Y; Golebiewska, U; Kielczewska, D; Boyd, S C; Stachyra, A L; Wilkes, R J; Young, K K

    2001-06-18

    We report the result of a search for neutrino oscillations using precise measurements of the recoil electron energy spectrum and zenith angle variations of the solar neutrino flux from 1258 days of neutrino-electron scattering data in Super-Kamiokande. The absence of significant zenith angle variation and spectrum distortion places strong constraints on neutrino mixing and mass difference in a flux-independent way. Using the Super-Kamiokande flux measurement in addition, two allowed regions at large mixing are found.

  17. The analysis of solar models: Neutrinos and oscillations

    Science.gov (United States)

    Ulrich, R. K.; Rhodes, E. J., Jr.; Tomczyk, S.; Dumont, P. J.; Brunish, W. M.

    1983-01-01

    Tests of solar neutrino flux and solar oscillation frequencies were used to assess standard stellar structure theory. Standard and non-standard solar models are enumerated and discussed. The field of solar seismology, wherein the solar interior is studied from the measurement of solar oscillations, is introduced.

  18. SNO results and neutrino magnetic moment solution to the solar neutrino problem

    Indian Academy of Sciences (India)

    Debasish Majumdar

    2002-01-01

    We have analysed the solar neutrino data obtained from chlorine, gallium and Super-Kamiokande (SK) experiments (1258 days) and also the new results that came from Sudbury Neutrino Observatory (SNO) charge current (CC) and elastic scattering (ES) experiments considering that the solar neutrino deficit is due to the interaction of neutrino transition magnetic moment with the solar magnetic field. We have also analysed the moments of the spectrum of scattered electrons at SK. Another new feature in the analysis is that for the global analysis, we have replaced the spectrum by its centroid.

  19. Solar neutrino physics with low-threshold dark matter detectors

    CERN Document Server

    Billard, J; Figueroa-Feliciano, E

    2014-01-01

    Dark matter detectors will soon be sensitive to Solar neutrinos via two distinct channels: coherent neutrino-nucleus scattering and neutrino electron elastic scattering. We establish an analysis method for extracting Solar model properties and neutrino properties from these measurements, including the possible effects of sterile neutrinos which have been hinted at by some reactor experiments and cosmological measurements. Even including sterile neutrinos, through the coherent scattering channel a 1 ton-year exposure with a low-threshold Germanium detector could improve on the current measurement of the normalization of the $^8$B Solar neutrino flux down to 3% or less. Combining with the elastic scattering data will provide constraints on both the high and low energy survival probability, and will improve on the uncertainty on the active-to-sterile mixing angle by a factor of two. This sensitivity to active-to-sterile transitions is competitive and complementary to forthcoming dedicated short baseline sterile ...

  20. Possible explanation of the solar-neutrino puzzle

    Science.gov (United States)

    Bethe, H. A.

    1986-01-01

    A new derivation of the Mikheyev and Smirnov (1985) mechanism for the conversion of electron neutrinos into mu neutrinos when traversing the sun is presented, and various hypotheses set forth. It is assumed that this process is responsible for the detection of fewer solar neutrinos than expected, with neutrinos below a minimum energy, E(m), being undetectable. E(m) is found to be about 6 MeV, and the difference of the squares of the respective neutrino masses is calculated to be 6 X 10 to the - 5th sq eV. A restriction on the neutrino mixing angle is assumed such that the change of density near the crossing point is adiabatic. It is predicted that no resonance conversion of neutrinos will occur in the dense core of supernovae, but conversion of electron neutrinos to mu neutrinos will occur as they escape outward through a density region around 100.

  1. Scattering of low-energy neutrinos on atomic shells

    Energy Technology Data Exchange (ETDEWEB)

    Babič, Andrej [Dept. of Dosimetry and Application of Ionizing Radiation, Czech Technical University, 115 19 Prague, Czech Rep. (Czech Republic); Institute of Experimental and Applied Physics, Czech Technical University, 128 00 Prague (Czech Republic); Bogoliubov Laboratory of Theoretical Physics, Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Šimkovic, Fedor [Institute of Experimental and Applied Physics, Czech Technical University, 128 00 Prague (Czech Republic); Bogoliubov Laboratory of Theoretical Physics, Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Department of Nuclear Physics and Biophysics, Comenius University, 842 48 Bratislava (Slovakia)

    2015-10-28

    We present a derivation of the total cross section for inelastic scattering of low-energy solar neutrinos and reactor antineutrinos on bound electrons, resulting in a transition of the electron to an excited state. The atomic-shell structure of various chemical elements is treated in terms of a nonrelativistic approximation. We estimate the interaction rates for modern neutrino detectors, in particular the Borexino and GEMMA experiments. We establish that in these experiments the effect can be safely neglected, but it could be accessible to future large-volume neutrino detectors with low energy threshold.

  2. 7Be solar neutrino measurement with KamLAND

    NARCIS (Netherlands)

    Gando, A.; et al., [Unknown; Decowski, M.P.

    2015-01-01

    We report a measurement of the neutrino-electron elastic scattering rate of 862 keV Be7 solar neutrinos based on a 165.4 kt d exposure of KamLAND. The observed rate is 582±94(kt d)−1, which corresponds to an 862-keV Be7 solar neutrino flux of (3.26±0.52)×109cm−2s−1, assuming a pure electron-flavor f

  3. Earth regeneration effect in solar neutrino oscillations an analytic approach

    CERN Document Server

    Lisi, E; Lisi, Eligio; Montanino, Daniele

    1997-01-01

    We present a simple and accurate method for computing analytically the regeneration probabilities of solar neutrinos in the Earth. We apply this method to the calculation of several solar model independent quantities t= han can be measured by the SuperKamiokande and Sudbury Neutrino Observatory experiments.

  4. GNO Solar Neutrino Observations Results for GNOI

    CERN Document Server

    Altmann, M; Belli, P; Bellotti, E; Bernabei, R; Burkert, E; Cattadori, C; Cerichelli, G; Chiarini, M; Cribier, Michel; Re, G D; Ebert, K H; Von Feilitzsch, F; Ferrari, N; Hampel, W; Handt, J; Henrich, E; Heusser, G; Kiko, J; Kirsten, T; Lachenmaier, T; Lanfranchi, J; Laubenstein, M; Motta, D; Rau, W; Richter, H; Wänninger, S; Wójcik, M; Zanotti, L

    2000-01-01

    We report the first GNO solar neutrino results for the measuring period GNOI, solar exposure time May 20, 1998 till January 12, 2000. In the present analysis, counting results for solar runs SR1 - SR19 were used till April 4, 2000. With counting completed for all but the last 3 runs (SR17 - SR19), the GNO I result is [65.8 +10.2 -9.6 (stat.) +3.4 -3.6 (syst.)]SNU (1sigma) or [65.8 + 10.7 -10.2 (incl. syst.)]SNU (1sigma) with errors combined. This may be compared to the result for Gallex(I-IV), which is [77.5 +7.6 -7.8 (incl. syst.)] SNU (1sigma). A combined result from both GNOI and Gallex(I-IV) together is [74.1 + 6.7 -6.8 (incl. syst.)] SNU (1sigma).

  5. Solar neutrino physics with low-threshold dark matter detectors

    Science.gov (United States)

    Billard, J.; Strigari, L. E.; Figueroa-Feliciano, E.

    2015-05-01

    Dark matter detectors will soon be sensitive to Solar neutrinos via two distinct channels: coherent neutrino-nucleus and neutrino-electron elastic scatterings. We establish an analysis method for extracting Solar model properties and neutrino properties from these measurements, including the possible effects of sterile neutrinos which have been hinted at by some reactor experiments and cosmological measurements. Even including sterile neutrinos, through the coherent scattering channel, a 1 ton-year exposure with a low-threshold background free Germanium detector could improve on the current measurement of the normalization of the B 8 Solar neutrino flux down to 3% or less. Combining with the neutrino-electron elastic scattering data will provide constraints on both the high- and low-energy survival probability and will improve on the uncertainty on the active-to-sterile mixing angle by a factor of 2. This sensitivity to active-to-sterile transitions is competitive and complementary to forthcoming dedicated short baseline sterile neutrino searches with nuclear decays. Finally, we show that such solar neutrino physics potentials can be reached as long as the signal-to-noise ratio is better than 0.1.

  6. Frequentist analyses of solar neutrino data

    CERN Document Server

    Creminelli, P; Strumia, A; Creminelli, Paolo; Signorelli, Giovanni; Strumia, Alessandro

    2001-01-01

    The solar neutrino data are analyzed in a frequentist framework, using the Crow-Gardner and Feldman-Cousins prescriptions for the construction of confidence regions. Including in the fit only the total rates measured by the various experiments, both methods give results similar to the commonly used Delta chi^2-cut approximation. When fitting the full data set, the Delta chi^2-cut still gives a good approximation of the Feldman-Cousins regions. However, a careful statistical analysis significantly reduces the goodness-of-fit of the SMA and LOW solutions.

  7. E sub 6 leptoquarks and the solar neutrino problem

    Science.gov (United States)

    Roulet, Esteban

    1991-01-01

    The possibility that non-conventional neutrino oscillations take place in the superstring inspired E sub 6 models is considered. In this context, the influence of leptoquark mediated interactions of the neutrinos with nucleons in the resonant flavor conversion is discussed. It is shown that this effect can be significant for v sub e - v sub tau oscillations if these neutrinos have masses required in the ordinary Mikheyev-Smirnov-Wolfenstein (MSW) effect, and may lead to a solution of the solar neutrino problem even in the absence of vacuum mixings. On the other hand, this model cannot lead to a resonant behavior in the sun if the neutrinos are massless.

  8. Status of the solution to the solar neutrino problem based on non-standard neutrino interactions

    CERN Document Server

    Bergmann, S R; De Holanda, P C; Krastev, P I; Nunokawa, H

    2000-01-01

    We analyze the current status of the solution to the solar neutrino problem based both on: a) non-standard flavor changing neutrino interactions (FCNI) and b) non-universal flavor diagonal neutrino interactions (FDNI). We find that FCNI and FDNI with matter in the sun as well as in the earth provide a good fit not only to the total rate measured by all solar neutrino experiments but also to the day-night and seasonal variations of the event rate, as well as the recoil electron energy spectrum measured by the SuperKamiokande collaboration. This solution does not require massive neutrinos and neutrino mixing in vacuum. Stringent experimental constraints on FCNI from bounds on lepton flavor violating decays and on FDNI from limits on lepton universality violation rule out $\

  9. A possible solution to the solar neutrino problem: Relativistic corrections to the Maxwellian velocity distribution

    OpenAIRE

    2001-01-01

    The relativistic corrections to the Maxwellian velocity distribution are needed for standard solar models. Relativistic equilibrium velocity distribution, if adopted in standard solar models, will lower solar neutrino fluxes and change solar neutrino energy spectra but keep solar sound speeds. It is possibly a solution to the solar neutrino problem.

  10. Muon and Cosmogenic Neutron Detection in Borexino

    CERN Document Server

    Bellini, G; Bick, D; Bonetti, S; Avanzini, M Buizza; Caccianiga, B; Cadonati, L; Calaprice, F; Carraro, C; Chavarria, A; Chepurnov, A; D'Angelo, D; Davini, S; Derbin, A; Etenko, A; von Feilitzsch, F; Fomenko, K; Franco, D; Galbiati, C; Gazzana, S; Ghiano, C; Giammarchi, M; Goeger-Neff, M; Goretti, A; Guardincerri, E; Hardy, S; Ianni, Aldo; Ianni, Andrea; Joyce, M; Kobychev, V; Koshio, Y; Korablev, D; Korga, G; Kryn, D; Laubenstein, M; Lendvai, C; Lewke, T; Litvinovich, E; Loer, B; Lombardi, F; Lombardi, P; Ludhova, L; Machulin, I; Manecki, S; Maneschg, W; Manuzio, G; Meindl, Q; Meroni, E; Miramonti, L; Misiaszek, M; Montanari, D; Muratova, V; Oberauer, L; Obolensky, M; Ortica, F; Pallavicini, M; Papp, L; Perasso, L; Perasso, S; Pocar, A; Raghavan, R S; Ranucci, G; Razeto, A; Re, A; Romani, A; Rountree, D; Sabelnikov, A; Saldanha, R; Salvo, C; Schönert, S; Simgen, H; Skorokhvatov, M; Smirnov, O; Sotnikov, A; Sukhotin, S; Suvorov, Y; Tartaglia, R; Testera, G; Vignaud, D; Vogelaar, R B; Winter, J; Wojcik, M; Wright, A; Wurm, M; Xu, J; Zaimidoroga, O; Zavatarelli, S; Zuzel, G

    2011-01-01

    Borexino, a liquid scintillator detector at LNGS, is designed for the detection of neutrinos and antineutrinos from the Sun, supernovae, nuclear reactors, and the Earth. The feeble nature of these signals requires a strong suppression of backgrounds below a few MeV. Very low intrinsic radiogenic contamination of all detector components needs to be accompanied by the efficient identification of muons and of muon-induced backgrounds. Muons produce unstable nuclei by spallation processes along their trajectory through the detector whose decays can mimic the expected signals; for isotopes with half-lives longer than a few seconds, the dead time induced by a muon-related veto becomes unacceptably long, unless its application can be restricted to a sub-volume along the muon track. Consequently, not only the identification of muons with very high efficiency but also a precise reconstruction of their tracks is of primary importance for the physics program of the experiment. The Borexino inner detector is surrounded b...

  11. Constraining Majorana neutrino electromagnetic properties from the LMA-MSW solution of the solar neutrino problem

    CERN Document Server

    Grimus, Walter; Schwetz, T; Tortola, M A; Valle, José W F

    2003-01-01

    In this paper we use solar neutrino data to derive stringent bounds on Majorana neutrino transition moments (TMs). Should such be present, they would contribute to the neutrino--electron scattering cross section and hence alter the signal observed in Super-Kamiokande. Motivated by the growing robustness of the LMA-MSW solution of the solar neutrino problem indicated by recent data, and also by the prospects of its possible confirmation at KamLAND, we assume the validity of this solution, and we constrain neutrino TMs by using the latest global solar neutrino data. We find that all elements of the TM matrix can be bounded at the same time. Furthermore, we show how reactor data play a complementary role to the solar neutrino data, and use the combination of both data sets to improve the current bounds. Performing a simultaneous fit of LMA-MSW oscillation parameters and TMs we find that $6.3 \\times 10^{-10}\\mu_B$ and $2.0 \\times 10^{-10}\\mu_B$ are the 90% C.L. bounds from solar and combined solar + reactor data,...

  12. 7Be Solar Neutrino Measurement with KamLAND

    CERN Document Server

    Gando, A; Hanakago, H; Ikeda, H; Inoue, K; Ishidoshiro, K; Ishikawa, H; Kishimoto, Y; Koga, M; Matsuda, R; Matsuda, S; Mitsui, T; Motoki, D; Nakajima, K; Nakamura, K; Obata, A; Oki, A; Oki, Y; Otani, M; Shimizu, I; Shirai, J; Suzuki, A; Tamae, K; Ueshima, K; Watanabe, H; Xu, B D; Yamada, S; Yamauchi, Y; Yoshida, H; Kozlov, A; Takemoto, Y; Yoshida, S; Grant, C; Keefer, G; McKee, D W; Piepke, A; Banks, T I; Bloxham, T; Freedman, S J; Fujikawa, B K; Han, K; Hsu, L; Ichimura, K; Murayama, H; O'Donnell, T; Steiner, H M; Winslow, L A; Dwyer, D; Mauger, C; McKeown, R D; Zhang, C; Berger, B E; Lane, C E; Maricic, J; Miletic, T; Learned, J G; Sakai, M; Horton-Smith, G A; Tang, A; Downum, K E; Tolich, K; Efremenko, Y; Kamyshkov, Y; Perevozchikov, O; Karwowski, H J; Markoff, D M; Tornow, W; Detwiler, J A; Enomoto, S; Heeger, K; Decowski, M P

    2014-01-01

    We report a measurement of the neutrino-electron elastic scattering rate of 862 keV 7Be solar neutrinos based on a 165.4 kton-day exposure of KamLAND. The observed rate is 582 +/- 90 (kton-day)^-1, which corresponds to a 862 keV 7Be solar neutrino flux of (3.26 +/- 0.50) x 10^9 cm^-2s^-1, assuming a pure electron flavor flux. Comparing this flux with the standard solar model prediction and further assuming three flavor mixing, a nu_e survival probability of 0.66 +/- 0.14 is determined from the KamLAND data. Utilizing a global three flavor oscillation analysis, we obtain a total 7Be solar neutrino flux of (5.82 +/- 0.98) x 10^9 cm^-2s^-1, which is consistent with the standard solar model predictions.

  13. The Role of Solar Neutrinos in the Jupiter

    CERN Document Server

    Burov, Valery

    2008-01-01

    Judging from the fact that the planet Jupiter is bigger in size than the Earth by 10^3 while is smaller than the Sun by 10^3 and that the average distance of the Jupiter from the Sun is 5.203 a.u., the solar neutrinos, when encounter the Jupiter, may have some accumulating effects bigger than on the Earth. We begin by estimating how much energy/power carried by solar neutrinos get transferred by this unique process, to confirm that solar neutrinos, despite of their feeble neutral weak current interactions, might deposit enough energy in the Jupiter. We also speculate on the other remarkable effects.

  14. Solving Solar Neutrino Puzzle via LMA MSW Conversion

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    We analyze the existing solar neutrino experiment data and show the allowed regions. The result from SNO's salt phase itself restricts quite a lot the allowed region's area. Reactor neutrinos play an important role in determining oscillation parameters. KamLAND gives decisive conclusion on the solution to the solar neutrino puzzle, in particular, the spectral distortion in the 766.3 Ty KamLAND data gives another new improvement in the constraint of solar MSW-LMA solutions. We confirm that at 99. 73% C.L. the high-LMA solution is excluded.

  15. Constraints on decay plus oscillation solutions of the solar neutrino problem

    CERN Document Server

    Joshipura, A S; Mohanty, S; Joshipura, Anjan S.; Masso, Eduard; Mohanty, Subhendra

    2002-01-01

    We examine the constraints on non-radiative decay of neutrinos from the observations of solar neutrino experiments. The standard oscillation hypothesis among three neutrinos solves the solar and atmospheric neutrino problems. Decay of a massive neutrino mixed with the electron neutrino results in the depletion of the solar neutrino flux. We introduce neutrino decay in the oscillation hypothesis and demand that decay does not spoil the successful explanation of solar and atmospheric observations. We obtain a lower bound on the ratio of the lifetime over the mass of $\

  16. Seasonal Dependence in the Solar Neutrino Flux

    CERN Document Server

    De Holanda, P C; González-Garciá, M Concepción; Valle, José W F

    1999-01-01

    MSW solutions of the solar neutrino problem predict a seasonal dependence of the zenith angle distribution of the event rates, due to the non-zero latitude at the Super-Kamiokande site. We calculate this seasonal dependence and compare it with the expectations in the no-oscillation case as well as just-so scenario, in the light of the latest Super-Kamiokande 708-day data. The seasonal dependence can be sizeable in the large mixing angle MSW solution and would be correlated with the day-night effect. This may be used to discriminate between MSW and just-so scenarios and should be taken into account in refined fits of the data.

  17. On the Study of Solar Flares with Neutrino Observatories

    CERN Document Server

    ,

    2016-01-01

    Since the end of the eighties, in response to a reported increase of the total neutrino flux in the Homestake experiment in coincidence with solar flares, neutrino detectors have searched for signals of neutrinos associated with solar flare activity. Protons which are accelerated by the magnetic structures of such flares may collide with the solar atmosphere, producing mesons which subsequently decay, resulting in neutrinos at O(MeV-GeV) energies. The study of such neutrinos would provide a new window on the underlying physics of the acceleration process. The sensitivity to solar flares of the IceCube Neutrino Observatory, located at the geographical South Pole, is currently under study. We introduce a new approach for a time profile analysis. This is based on a stacking method of selected solar flares which are likely to be connected with pion production. An initial approach towards a neutrino search using the current IceCube experiment as well as first efforts to improve the detection efficiency in the futu...

  18. Sterile neutrinos in the 3+s scenario and solar data

    CERN Document Server

    Pulido, Joao

    2013-01-01

    The flatness of the SuperKamiokande neutrino electron scattering spectrum and the apparent downturn of the charged current spectrum in the SNO data which the Large Mixing Angle solution (LMA) to the solar neutrino problem fails to predict are analysed in the context of an extension to the standard electroweak model with light sterile neutrinos. It is found that a sterile neutrino which is quasi degenerate with the active ones with $\\Delta m^2_{41}=10^{-5}eV^2$ and mixing $sin\\theta_{14}=0.04$ provides a suitable improvement to the LMA data fits.

  19. A search for hep solar neutrinos at the Sudbury Neutrino Observatory

    Science.gov (United States)

    Winchester, Timothy J.

    Solar neutrinos from the fusion hep reaction, (helium-3 fusing with a proton to become helium-4, releasing a positron and neutrino), have previously remained undetected due to their flux being about one one-thousandth that of boron-8 neutrinos. These neutrinos are interesting theoretically because they are less dependent on solar composition than other solar neutrinos, and therefore provide a somewhat independent test of the Standard Solar Model. In this analysis, we develop a new event fitter for existing data from the Sudbury Neutrino Observatory. We also use the fitter to remove backgrounds that previously limited the fiducial volume, which we increase by 30%. We use a modified Wald-Wolfowitz test to increase the amount of live time by 200 days (18%) and show that this data is consistent with the previously-used data. Finally, we develop a Bayesian analysis technique to make full use of the posterior distributions of energy returned by the event fitter. In the first significant detection of hep neutrinos, we find that the most-probable rate of hep events is 3.5 x 10. 4 /cm. 2/s, which is significantly higher than the theoretical prediction. We find that the 95% credible region extends from 1.0 to 7.2 x 10. 4 /cm. 2/s, and that we can therefore exclude a rate of 0 hep events at greater than 95% probability.

  20. Solar neutrino oscillation parameters after first KamLAND results

    CERN Document Server

    Fogli, G L; Marrone, A; Montanino, D; Palazzo, A; Rotunno, A M

    2003-01-01

    We analyze the energy spectrum of reactor neutrino events recently observed in the Kamioka Liquid scintillator Anti-Neutrino Detector (KamLAND) and combine them with solar and terrestrial neutrino data, in the context of two- and three-family active neutrino oscillations. In the 2-neutrino case, we find that the solution to the solar neutrino problem at large mixing angle (LMA) is basically split into two sub-regions, that we denote as LMA-I and LMA-II. The LMA-I solution, characterized by lower values of the squared neutrino mass gap, is favored by the global data fit. This picture is not significantly modified in the 3-neutrino mixing case. A brief discussion is given about the discrimination of the LMA-I and LMA-II solutions with future KamLAND data. In both the 2- and 3-neutrino cases, we present a detailed analysis of the post-KamLAND bounds on the oscillation parameters.

  1. The Solar Solution: Tracking the Sun with Low Energy Neutrinos

    CERN Document Server

    Hartman, Nicole

    2016-01-01

    As neutrinos become a significant background for projected dark matter experiments, the community will become concerned with determining if events counted in a dark matter experiment are good dark matter candidates or low-energy neutrinos from astrophysical sources. We investigate the feasibility of using neutrino-electron scattering in a terrestrial detector medium as a means to determine the flight direction of the original, low-energy solar neutrino.Using leading-order weak interactions in the Standard Model and constrains from energy and momentum conservation, we developed a simple simulation that suggests that 68% of the time the ejected electron would be within 0.99 radians of the incident neutrino's direction. This suggests that it may be fruitful to pursue low-energy neutrino detection capability that can utilize such ejected electrons.

  2. Solar, supernova, atmospheric and geo neutrino studies using JUNO detector

    CERN Document Server

    Guo, Wan-lei; Li, Yufeng; Salamanna, Giuseppe

    2016-01-01

    Aside from its primary purpose of shedding light on the mass hierarchy (MH) using reactor anti-neutrinos, the JUNO experiment in Jiangmen (China) will also contribute to study neutrinos from non-reactor sources. In this poster we review JUNO's goals in the realms of supernova, atmospheric, solar and geo-neutrinos; present the related experimental issues and provide the current estimates of its potential. For a typical galactic SN at a distance of 10 kpc, JUNO will record about 5000 events from inverse beta decay, 2000 events from elastic neutrino-proton scattering, 300 events from neutrino-electron scattering, and the charged current and neutral current interactions on the ${^{12}}{\\rm C}$ nuclei. For atmospheric neutrinos, JUNO should be able to detect $\

  3. Super-Kamiokande's Solar Neutrino Results

    Energy Technology Data Exchange (ETDEWEB)

    Nakahata, Masayuki [Kamioka Observatory, Institute for Cosmic Ray research, University of Tokyo, Higashi-Mozumi, Kamioka-cho, Hida-shi, Gifu, 506-1205 (Japan)

    2005-06-15

    Results from solar neutrino measurements at Super-Kamiokande(SK) are presented. Precise measurements of the day/night difference and the energy spectrum obtained by 1496 days' SK-I data indicate that the neutrino oscillation parameters are in the LMA region with a constraint of the total flux. The energy spectrum upturn which is expected at the best fit oscillation parameters obtained by global analyses is not observed yet. SK-II has been taking data since December 2002. Preliminary results from SK-II are consistent with that from SK-I. Future prospects of solar neutrino measurements at SK are also discussed.

  4. NSI can improve LMA predictions: neutrino decay in solar matter?

    CERN Document Server

    Pulido, Joao

    2010-01-01

    We investigate the prospects for non-standard interactions (NSI) in solar neutrino propagation and detection and find that these may solve the tension between the observed flatness of the SuperKamiokande electron spectrum and its LMA prediction which has a clear negative slope. Also the Cl rate prediction from NSI comes within 1$\\sigma$ of its experimental value instead of the LMA one which lies more than 2$\\sigma$ above. A remarkable consequence of NSI for solar neutrinos is the possibility of neutrino decay into majorons and antineutrinos whose appearance probability is calculated but found to be rather small.

  5. Update of GALLEX solar neutrino results and implications

    Energy Technology Data Exchange (ETDEWEB)

    Kirsten, T. [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany)

    1995-01-01

    The galliumchloride detector operated by the GALLEX-collaboration in the Gran Sasso Underground Laboratory responds primarily to pp-neutrinos. They are produced in the primary fusion reaction of hydrogen into deuterium and directly coupled to the solar luminosity. Standard Solar Models predict ca. 58% of the total signal expected in GALLEX (123-132 SNU) to be due to pp-neutrinos. The relative pp-neutrino dominance becomes even larger if the deficit of higher energy neutrinos (as observed in the Homestake- and Kamiokande experiments) is considered. During the first data taking period, 15 solar runs had been performed within the exposure period 14.5.1991 - 29.4.1992. The result, 81 {+-} 17 {+-} 9 SNU provided the first experimental evidence for pp-neutrinos from the Sun. At the same time, it confirmed the depression of higher energy neutrino fluxes relative to the model predictions. Here the authors report the results of 15 more solar neutrino runs, covering the period 19.8.92 - 13.10.93. They obtain 78 {+-} 13 {+-} 5 SNU. Evaluated together, the result for all 30 runs is 79 {+-} 10 {+-} 6 SNU. While the SNU rate of GALLEX I is well reproduced the statistical error has been reduced so substantially that a value of signal +2{sigma} is required to accommodate not only pp-and pep- but also the {sup 7}Be-neutrino induced {sup 71}Ge-production. Contrary, the fate of {sup 8}B-neutrinos has only little discernible effect on the GALLEX data. In conclusion, with the present errors GALLEX constitutes a 2.5 {sigma} problem for {sup 7}Be neutrinos within the frame of {open_quotes}astrophysical{close_quotes} solutions. Alternatively, the particle physics solution (MSW-effect) can consistently explain all available solar neutrino results, leading to a most probable mass scale with the muon-neutrino at approximately 3 meV (milli-eV). However, since the GALLEX result allows the presence of pp and pep neutrinos at full strength. the latter explanation of the data is not forced.

  6. Solar Neutrino Measurements in Super-Kamiokande-IV

    CERN Document Server

    :,; Haga, Y; Hayato, Y; Ikeda, M; Iyogi, K; Kameda, J; Kishimoto, Y; Marti, Ll; Miura, M; Moriyama, S; Nakahata, M; Nakajima, T; Nakayama, S; Orii, A; Sekiya, H; Shiozawa, M; Sonoda, Y; Takeda, A; Tanaka, H; Takenaga, Y; Tasaka, S; Tomura, T; Ueno, K; Yokozawa, T; Akutsu, R; Irvine, T; Kaji, H; Kajita, T; Kametani, I; Kaneyuki, K; Lee, K P; Nishimura, Y; McLachlan, T; Okumura, K; Richard, E; Labarga, L; Fernandez, P; Blaszczyk, F d M; Gustafson, J; Kachulis, C; Kearns, E; Raaf, 32 J L; Stone, J L; Sulak, 32 L R; Berkman, S; Tobayama, S; Goldhaber, M; Bays, K; Carminati, G; Griskevich, N J; Kropp, W R; Mine, S; Renshaw, A; Smy, M B; Sobel, H W; Takhistov, V; Weatherly, P; Ganezer, K S; Hartfiel, B L; Hill, J; Keig, W E; Hong, N; Kim, J Y; Lim, I T; Park, R G; Akiri, T; Albert, J B; Himmel, A; Li, Z; O'Sullivan, E; Scholberg, K; Walter, C W; Wongjirad, T; Ishizuka, T; Nakamura, T; Jang, J S; Choi, K; Learned, J G; Matsuno, S; Smith, S N; Friend, M; Hasegawa, T; Ishida, T; Ishii, T; Kobayashi, T; Nakadaira, T; Nakamura, K; Nishikawa, K; Oyama, Y; Sakashita, K; Sekiguchi, T; Tsukamoto, T; Nakano, Y; Suzuki, A T; Takeuchi, Y; Yano, T; Cao, S V; Hayashino, T; Hiraki, T; Hirota, S; Huang, K; Ieki, K; Jiang, M; Kikawa, T; Minamino, A; Murakami, A; Nakaya, T; Patel, N D; Suzuki, K; Takahashi, S; Wendell, R A; Fukuda, Y; Itow, Y; Mitsuka, G; Muto, F; Suzuki, T; Mijakowski, P; Frankiewicz, K; Hignight, J; Imber, J; Jung, C K; Li, X; Palomino, J L; Santucci, G; Taylor, I; Vilela, C; Wilking, M J; Yanagisawa, C; Fukuda, D; Ishino, H; Kayano, T; Kibayashi, A; Koshio, Y; Mori, T; Sakuda, M; Takeuchi, J; Yamaguchi, R; Kuno, Y; Tacik, R; Kim, S B; Okazawa, H; Choi, Y; Ito, K; Nishijima, K; Koshiba, M; Totsuka, Y; Suda, Y; Yokoyama, M; Nantais, C M; Martin, J F; de Perio, P; Tanaka, H A; Konaka, A; Chen, S; Sui, H; Wan, L; Yang, Z; Zhang, H; Zhang, Y; Connolly, K; Dziomba, M; Wilkes, R J

    2016-01-01

    Upgraded electronics, improved water system dynamics, better calibration and analysis techniques allowed Super-Kamiokande-IV to clearly observe very low-energy 8B solar neutrino interactions, with recoil electron kinetic energies as low as 3.49 MeV. Super-Kamiokande-IV data-taking began in September of 2008; this paper includes data until February 2014, a total livetime of 1664 days. The measured solar neutrino flux is (2.308+-0.020(stat.) + 0.039-0.040(syst.)) x 106/(cm2sec) assuming no oscillations. The observed recoil electron energy spectrum is consistent with no distortions due to neutrino oscillations. An extended maximum likelihood fit to the amplitude of the expected solar zenith angle variation of the neutrino-electron elastic scattering rate in SK-IV results in a day/night asymmetry of (-3.6+-1.6(stat.)+-0.6(syst.))%. The SK-IV solar neutrino data determine the solar mixing angle as sin2 theta_12 = 0.327+0.026-0.031, all SK solar data (SK-I, SK-II, SK III and SKIV) measures this angle to be sin2 the...

  7. Solar neutrino measurements in Super-Kamiokande-IV

    Science.gov (United States)

    Abe, K.; Haga, Y.; Hayato, Y.; Ikeda, M.; Iyogi, K.; Kameda, J.; Kishimoto, Y.; Marti, Ll.; Miura, M.; Moriyama, S.; Nakahata, M.; Nakajima, T.; Nakayama, S.; Orii, A.; Sekiya, H.; Shiozawa, M.; Sonoda, Y.; Takeda, A.; Tanaka, H.; Takenaga, Y.; Tasaka, S.; Tomura, T.; Ueno, K.; Yokozawa, T.; Akutsu, R.; Irvine, T.; Kaji, H.; Kajita, T.; Kametani, I.; Kaneyuki, K.; Lee, K. P.; Nishimura, Y.; McLachlan, T.; Okumura, K.; Richard, E.; Labarga, L.; Fernandez, P.; Blaszczyk, F. d. M.; Gustafson, J.; Kachulis, C.; Kearns, E.; Raaf, J. L.; Stone, J. L.; Sulak, L. R.; Berkman, S.; Tobayama, S.; Goldhaber, M.; Bays, K.; Carminati, G.; Griskevich, N. J.; Kropp, W. R.; Mine, S.; Renshaw, A.; Smy, M. B.; Sobel, H. W.; Takhistov, V.; Weatherly, P.; Ganezer, K. S.; Hartfiel, B. L.; Hill, J.; Keig, W. E.; Hong, N.; Kim, J. Y.; Lim, I. T.; Park, R. G.; Akiri, T.; Albert, J. B.; Himmel, A.; Li, Z.; O'Sullivan, E.; Scholberg, K.; Walter, C. W.; Wongjirad, T.; Ishizuka, T.; Nakamura, T.; Jang, J. S.; Choi, K.; Learned, J. G.; Matsuno, S.; Smith, S. N.; Friend, M.; Hasegawa, T.; Ishida, T.; Ishii, T.; Kobayashi, T.; Nakadaira, T.; Nakamura, K.; Nishikawa, K.; Oyama, Y.; Sakashita, K.; Sekiguchi, T.; Tsukamoto, T.; Nakano, Y.; Suzuki, A. T.; Takeuchi, Y.; Yano, T.; Cao, S. V.; Hayashino, T.; Hiraki, T.; Hirota, S.; Huang, K.; Ieki, K.; Jiang, M.; Kikawa, T.; Minamino, A.; Murakami, A.; Nakaya, T.; Patel, N. D.; Suzuki, K.; Takahashi, S.; Wendell, R. A.; Fukuda, Y.; Itow, Y.; Mitsuka, G.; Muto, F.; Suzuki, T.; Mijakowski, P.; Frankiewicz, K.; Hignight, J.; Imber, J.; Jung, C. K.; Li, X.; Palomino, J. L.; Santucci, G.; Taylor, I.; Vilela, C.; Wilking, M. J.; Yanagisawa, C.; Fukuda, D.; Ishino, H.; Kayano, T.; Kibayashi, A.; Koshio, Y.; Mori, T.; Sakuda, M.; Takeuchi, J.; Yamaguchi, R.; Kuno, Y.; Tacik, R.; Kim, S. B.; Okazawa, H.; Choi, Y.; Ito, K.; Nishijima, K.; Koshiba, M.; Totsuka, Y.; Suda, Y.; Yokoyama, M.; Bronner, C.; Calland, R. G.; Hartz, M.; Martens, K.; Obayashi, Y.; Suzuki, Y.; Vagins, M. R.; Nantais, C. M.; Martin, J. F.; de Perio, P.; Tanaka, H. A.; Konaka, A.; Chen, S.; Sui, H.; Wan, L.; Yang, Z.; Zhang, H.; Zhang, Y.; Connolly, K.; Dziomba, M.; Wilkes, R. J.; Super-Kamiokande Collaboration

    2016-09-01

    Upgraded electronics, improved water system dynamics, better calibration and analysis techniques allowed Super-Kamiokande-IV to clearly observe very low-energy 8B solar neutrino interactions, with recoil electron kinetic energies as low as ˜3.5 MeV . Super-Kamiokande-IV data-taking began in September of 2008; this paper includes data until February 2014, a total livetime of 1664 days. The measured solar neutrino flux is (2.308 ±0.020 (stat)-0.040 +0.039(syst ))×1 06/(cm2 sec ) assuming no oscillations. The observed recoil electron energy spectrum is consistent with no distortions due to neutrino oscillations. An extended maximum likelihood fit to the amplitude of the expected solar zenith angle variation of the neutrino-electron elastic scattering rate in SK-IV results in a day/night asymmetry of (-3.6 ±1.6 (stat )±0.6 (syst ))% . The SK-IV solar neutrino data determine the solar mixing angle as sin2θ12=0.327-0.031+0.026 , all SK solar data (SK-I, SK-II, SK III and SK-IV) measures this angle to be sin2θ12=0.334-0.023+0.027 , the determined mass-squared splitting is Δ m212=4.8-0.8+1.5×10-5 eV2 .

  8. Physics from solar neutrinos in dark matter direct detection experiments

    CERN Document Server

    Cerdeño, David G; Jubb, Thomas; Machado, Pedro A N; Vincent, Aaron C; hm, Céline Bøe

    2016-01-01

    The next generation of dark matter direct detection experiments will be sensitive to both coherent neutrino-nucleus and neutrino-electron scattering. This will enable them to explore aspects of solar physics, perform the lowest energy measurement of the weak angle to date, and probe contributions from new theories with light mediators. In this article, we compute the projected nuclear and electron recoil rates expected in several dark matter direct detection experiments due to solar neutrinos, and use these estimates to infer errors on future measurements of the neutrino fluxes, weak mixing angle and solar observables, as well as to constrain new physics in the neutrino sector. The combined rates of solar neutrino events in second generation experiments (SuperCDMS and LZ) can yield a measurement of the pp flux to 2.5% accuracy via electron recoil, and slightly improve the boron-8 flux determination. Assuming a low-mass argon phase, projected tonne-scale experiments like DARWIN can reduce the uncertainty on bo...

  9. New neutrino-nucleus reaction cross sections at solar, reactor and supernova neutrino energies

    Directory of Open Access Journals (Sweden)

    Suzuki Toshio

    2014-03-01

    Full Text Available Remarkable improvements in the evaluation of neutrino-nucleus reaction cross sections are obtained based on new shell-model Hamiltonians with proper tensor components. New ν-induced reaction cross sections on 12C, 13C, 56Fe, 56Ni and 40Ar are presented, and predictions for nucleosynthesis in supernova explosions, ν-oscillation effects and low-energy reactor and solar neutrino detection are discussed based on these new cross sections.

  10. Solar neutrino problem accounting for self-consistent magnetohydrodynamics solution for solar magnetic fields

    CERN Document Server

    Rashba, T I; Peña-Garay, C; Semikoz, V B; Valle, José W F

    2001-01-01

    The analysis of the resonant spin-flavour (RSF) solutions to the solar neutrino problem in the framework of simplest analytic solutions to the solar magneto-hydrodynamics (MHD) equations is presented. We performed the global fit of the recent solar neutrino data, including event rates as well as day and night recoil electron spectra induced by solar neutrino interactions in SuperKamiokande. We compare quantitatively our simplest MHD-RSF fit with vacuum oscillation (VAC) and MSW--type (SMA, LMA and LOW) solutions to the solar neutrino problem using a common well-calibrated theoretical calculation and fit procedure and find MHD-RSF fit to be somewhat better than those obtained for the favored neutrino oscillation solutions. We made the predictions for future experiments to disentangle the MHD-RSF scenario from other scenarios.

  11. The conjecture concerning time variations in the solar neutrino flux

    Science.gov (United States)

    Haubold, H. J.; Gerth, E.

    1985-01-01

    The results of the Fourier transformation of the unequally-spaced time series of the recorded Ar-37 production rate of the solar neutrino experiment (runs 18 to 80, 1970 to 1983) are reviewed. Significance criteria for every period discovered by the harmonic analysis are determined. A Fourier synthesis of certain discovered harmonics are performed. It seems that the solar neutrino flux increases shock-like with a period of approximately 8.3 years and after that breaks down. Possible connections between the periods found by the harmonic analysis and several observed phenomena on the solar surface are indicated.

  12. Neutrino Astrophysics

    CERN Document Server

    Volpe, Cristina

    2016-01-01

    We summarize the progress in neutrino astrophysics and emphasize open issues in our understanding of neutrino flavor conversion in media. We discuss solar neutrinos, core-collapse supernova neutrinos and conclude with ultra-high energy neutrinos.

  13. Limit On the Neutrino Magnetic Moment Using 1496 Days of Super-Kamiokande-i Solar Neutrino Data

    CERN Document Server

    Liu, D W; Fukuda, S; Fukuda, Y; Ishihara, K; Itow, Y; Koshio, Y; Minamino, A; Miura, M; Moriyama, S; Nakahata, M; Namba, T; Nambu, R; Obayashi, Y; Sakurai, N; Shiozawa, M; Suzuki, Y; Takeuchi, H; Takeuchi, Y; Yamada, S; Ishitsuka, M; Kajita, T; Kaneyuki, K; Nakayama, S; Okada, A; Ooyabu, T; Saji, C; Desai, S; Earl, M; Kearns, E; Messier, M D; Stone, J L; Sulak, L R; Walter, C W; Wang, W; Goldhaber, M; Barszczak, T; Casper, D; Cravens, J P; Gajewski, W; Kropp, W R; Mine, S; Smy, M B; Sobel, H W; Sterner, C W; Vagins, M R; Ganezer, K S; Hill, J; Keig, W E; Kim, J Y; Lim, I T; Ellsworth, R W; Tasaka, S; Kibayashi, A; Learned, J G; Matsuno, S; Takemori, D; Hayato, Y; Ichikawa, A K; Ishida, T; Ishii, T; Iwashita, T; Kameda, J; Kobayashi, T; Maruyama, T; Nakamura, K; Nitta, K; Oyama, Y; Sakuda, M; Totsuka, Y; Suzuki, A T; Hasegawa, M; Hayashi, K; Inagaki, T; Kato, I; Maesaka, H; Morita, T; Nakaya, T; Nishikawa, K; Sasaki, T; Ueda, S; Yamamoto, S; Haines, T J; Dazeley, S; Hatakeyama, S; Svoboda, R; Blaufuss, E; Goodman, J A; Guillian, G; Sullivan, G W; Turcan, D; Scholberg, K; Habig, A; Ackermann, M; Jung, C K; Kato, T; Kobayashi, K; Martens, K; Malek, M; Mauger, C; McGrew, C; Sharkey, E; Viren, B; Yanagisawa, C; Toshito, T; Mitsuda, C; Miyano, K; Shibata, T; Kajiyama, Y; Nagashima, Y; Takita, M; Yoshida, M; Kim, H I; Kim, S B; Yoo, J; Okazawa, H; Ishizuka, T; Choi, Y; Seo, H K; Gando, Y; Hasegawa, T; Inoue, K; Shirai, J; Suzuki, A; Koshiba, M; Hashimoto, T; Nakajima, Y; Nishijima, K; Ishino, H; Morii, M; Nishimura, R; Watanabe, Y; Kielczewska, D; Zalipska, J; Gran, R; Shiraishi, K K; Washburn, K; Wilkes, R J

    2004-01-01

    A search for a non-zero neutrino magnetic moment has been conducted using 1496 live days of solar neutrino data from {\\SK}. Specifically, we searched for distortions to the energy spectrum of recoil electrons arising from magnetic scattering due to a non-zero neutrino magnetic moment. In the absence of clear signal, we found $\\mu_{\

  14. Constraining neutrino oscillation parameters with current solar and atmospheric data

    CERN Document Server

    Maltoni, M; Tortola, M A; Valle, José W F

    2003-01-01

    We analyse the impact of recent solar and atmospheric data in the determination of the neutrino oscillation parameters, taking into account that both the solar nu_e and the atmospheric nu_mu may convert to a mixture of active and sterile neutrinos. In addition to the recent SNO neutral current (NC), spectral and day/night data we add the latest 1496-day solar and 1489-day atmospheric Super-K neutrino data samples. By investigating in detail the impact of the recent SNO NC, spectral and day/night data, we confirm the clear preference of the LMA solution of the solar neutrino problem and obtain that the LOW, VAC, SMA solutions are disfavoured with a Delta_chi^2 = 9, 9, 23, respectively. Furthermore, we find that the global solar data constrains the admixture of a sterile neutrino to be less than 45% at 99% CL. A pure sterile solution is ruled out with respect to the active one at 99.996% CL. By performing an improved fit of the atmospheric data, we also update the corresponding regions of oscillation parameters...

  15. Equivalence Principle from the Solar and Reactor Neutrino Observations

    Science.gov (United States)

    Valdiviesso, G. A.; Guzzo, M. M.; Holanda, P. C.

    2012-08-01

    A model for the Violation of the Equivalence Principle (VEP) on solar and reactor neutrinos is investigated, and a new limit for the VEP is obtained considering the mass-flavor mixing hypothesis and the VEP model. Our analysis showed that due to the effects on νe and ν disapearance channels, VEP effects can be at most of 1 part in 1014, assuming that neutrinos are mainly affected by the gravitational potential due to the Great Atractor.

  16. VEP oscillation solutions to the solar neutrino problem

    CERN Document Server

    Casini, H; Montemayor, R

    2000-01-01

    We study the solar neutrino problem within the framework of a parametrized post-Newtonian formulation for the gravitational interaction of the neutrinos, which incorporates a violation to the equivalence principle (VEP). Using the current data on the rates and the energy spectrum we find two possible oscillation solutions, both for a large mixing angle. One of them involves the MSW effect in matter and the other corresponds to vacuum oscillations. An interesting characteristic of this mechanism is that it predicts a semi-annual variation of the neutrino flux. Our analysis provides new constraints for some VEP parameters.

  17. Mantle geoneutrinos in KamLAND and Borexino

    CERN Document Server

    Fiorentini, G; Lisi, E; Mantovani, F; Rotunno, A M

    2012-01-01

    The KamLAND and Borexino experiments have observed, each at ~4 sigma level, signals of electron antineutrinos produced in the decay chains of thorium and uranium in the Earth's crust and mantle (Th and U geoneutrinos). Various pieces of geochemical and geophysical information allow an estimation of the crustal geoneutrino flux components with relatively small uncertainties. The mantle component may then be inferred by subtracting the estimated crustal flux from the measured total flux. To this purpose, we analyze in detail the experimental Th and U geoneutrino event rates in KamLAND and Borexino, including neutrino oscillation effects. We estimate the crustal flux at the two detector sites, using state-of-the-art information about the Th and U distribution on global and local scales. We find that crust-subtracted signals show hints of a residual mantle component, emerging at ~2.4 sigma level by combining the KamLAND and Borexino data. The inferred mantle flux slightly favors scenarios with relatively high Th ...

  18. First indication of terrestrial matter effects on solar neutrino oscillation.

    Science.gov (United States)

    Renshaw, A; Abe, K; Hayato, Y; Iyogi, K; Kameda, J; Kishimoto, Y; Miura, M; Moriyama, S; Nakahata, M; Nakano, Y; Nakayama, S; Sekiya, H; Shiozawa, M; Suzuki, Y; Takeda, A; Takenaga, Y; Tomura, T; Ueno, K; Yokozawa, T; Wendell, R A; Irvine, T; Kajita, T; Kaneyuki, K; Lee, K P; Nishimura, Y; Okumura, K; McLachlan, T; Labarga, L; Berkman, S; Tanaka, H A; Tobayama, S; Kearns, E; Raaf, J L; Stone, J L; Sulak, L R; Goldhabar, M; Bays, K; Carminati, G; Kropp, W R; Mine, S; Smy, M B; Sobel, H W; Ganezer, K S; Hill, J; Keig, W E; Hong, N; Kim, J Y; Lim, I T; Akiri, T; Himmel, A; Scholberg, K; Walter, C W; Wongjirad, T; Ishizuka, T; Tasaka, S; Jang, J S; Learned, J G; Matsuno, S; Smith, S N; Hasegawa, T; Ishida, T; Ishii, T; Kobayashi, T; Nakadaira, T; Nakamura, K; Oyama, Y; Sakashita, K; Sekiguchi, T; Tsukamoto, T; Suzuki, A T; Takeuchi, Y; Bronner, C; Hirota, S; Huang, K; Ieki, K; Ikeda, M; Kikawa, T; Minamino, A; Nakaya, T; Suzuki, K; Takahashi, S; Fukuda, Y; Choi, K; Itow, Y; Mitsuka, G; Mijakowski, P; Hignight, J; Imber, J; Jung, C K; Yanagisawa, C; Ishino, H; Kibayashi, A; Koshio, Y; Mori, T; Sakuda, M; Yano, T; Kuno, Y; Tacik, R; Kim, S B; Okazawa, H; Choi, Y; Nishijima, K; Koshiba, M; Totsuka, Y; Yokoyama, M; Martens, K; Marti, Ll; Vagins, M R; Martin, J F; de Perio, P; Konaka, A; Wilking, M J; Chen, S; Zhang, Y; Wilkes, R J

    2014-03-07

    We report an indication that the elastic scattering rate of solar B8 neutrinos with electrons in the Super-Kamiokande detector is larger when the neutrinos pass through Earth during nighttime. We determine the day-night asymmetry, defined as the difference of the average day rate and average night rate divided by the average of those two rates, to be [-3.2 ± 1.1(stat) ± 0.5(syst)]%, which deviates from zero by 2.7 σ. Since the elastic scattering process is mostly sensitive to electron-flavored solar neutrinos, a nonzero day-night asymmetry implies that the flavor oscillations of solar neutrinos are affected by the presence of matter within the neutrinos' flight path. Super-Kamiokande's day-night asymmetry is consistent with neutrino oscillations for 4 × 10(-5)  eV(2) ≤ Δm 2(21) ≤ 7 × 10(-5) eV(2) and large mixing values of θ12, at the 68% C.L.

  19. First Indication of Terrestrial Matter Effects on Solar Neutrino Oscillation

    CERN Document Server

    Renshaw, A; Hayato, Y; Iyogi, K; Kameda, J; Kishimoto, Y; Miura, M; Moriyama, S; Nakahata, M; Nakano, Y; Nakayama, S; Sekiya, H; Shiozawa, M; Suzuki, Y; Takeda, A; Takenaga, Y; Tomura, T; Ueno, K; Yokozawa, T; Wendell, R A; Irvine, T; Kajita, T; Kaneyuki, K; Lee, K P; Nishimura, Y; Okumura, K; McLachlan, T; Labarga, L; Berkman, S; Tanaka, H A; Tobayama, S; Kearns, E; Raaf, J L; Stone, J L; Sulak, L R; Goldhabar, M; Bays, K; Carminati, G; Kropp, W R; Mine, S; Smy, M B; Sobel, H W; Ganezer, K S; Hill, J; Keig, W E; Hong, N; Kim, J Y; Lim, I T; Akiri, T; Himmel, A; Scholberg, K; Walter, C W; Wongjirad, T; Ishizuka, T; Tasaka, S; Jang, J S; Learned, J G; Matsuno, S; Smith, S N; Hasegawa, T; Ishida, T; Ishii, T; Kobayashi, T; Nakadaira, T; Nakamura, K; Oyama, Y; Sakashita, K; Sekiguchi, T; Tsukamoto, T; Suzuki, A T; Takeuchi, Y; Bronner, C; Hirota, S; Huang, K; Ieki, K; Ikeda, M; Kikawa, T; Minamino, A; Nakaya, T; Suzuki, K; Takahashi, S; Fukuda, Y; Choi, K; Itow, Y; Mitsuka, G; Mijakowski, P; Hignight, J; Imber, J; Jung, C K; Yanagisawa, C; Ishino, H; Kibayashi, A; Koshio, Y; Mori, T; Sakuda, M; Yano, T; Kuno, Y; Tacik, R; Kim, S B; Okazawa, H; Choi, Y; Nishijima, K; Koshiba, M; Totsuka, Y; Yokoyama, M; Martens, K; Marti, Ll; Vagins, M R; Martin, J F; de Perio, P; Konaka, A; Wilking, M J; Chen, S; Zhang, Y; Wilkes, R J

    2013-01-01

    We report an indication that the elastic scattering rate of solar $^8$B neutrinos with electrons in the Super-Kamiokande detector is larger when the neutrinos pass through the Earth during nighttime. We determine the day/night asymmetry, defined as the difference of the average day rate and average night rate divided by the average of those two rates, to be $(-3.2\\pm1.1(\\text{stat})\\pm0.5(\\text{syst}))\\%$, which deviates from zero by 2.7 $\\sigma$. Since the elastic scattering process is mostly sensitive to electron-flavored solar neutrinos, a non-zero day/night asymmetry implies that the flavor oscillations of solar neutrinos are affected by the presence of matter within the neutrinos' flight path. Super-Kamiokande's day/night asymmetry is consistent with neutrino oscillations for $3\\times10^{-5}$eV$^2\\leq\\Delta m^2_{21}\\leq9\\times10^{-5}$eV$^2$ and large mixing values of $\\theta_{12}$, at the $68\\%$ C.L.

  20. Limits on the neutrino magnetic moment using 1496 days of Super-Kamiokande-I solar neutrino data.

    Science.gov (United States)

    Liu, D W; Ashie, Y; Fukuda, S; Fukuda, Y; Ishihara, K; Itow, Y; Koshio, Y; Minamino, A; Miura, M; Moriyama, S; Nakahata, M; Namba, T; Nambu, R; Obayashi, Y; Sakurai, N; Shiozawa, M; Suzuki, Y; Takeuchi, H; Takeuchi, Y; Yamada, S; Ishitsuka, M; Kajita, T; Kaneyuki, K; Nakayama, S; Okada, A; Ooyabu, T; Saji, C; Desai, S; Earl, M; Kearns, E; Messier, M D; Stone, J L; Sulak, L R; Walter, C W; Wang, W; Barszczak, T; Casper, D; Cravens, J P; Gajewski, W; Kropp, W R; Mine, S; Smy, M B; Sobel, H W; Sterner, C W; Vagins, M R; Ganezer, K S; Hill, J; Keig, W E; Kim, J Y; Lim, I T; Ellsworth, R W; Tasaka, S; Kibayashi, A; Learned, J G; Matsuno, S; Takemori, D; Hayato, Y; Ichikawa, A K; Ishida, T; Ishii, T; Iwashita, T; Kameda, J; Kobayashi, T; Maruyama, T; Nakamura, K; Nitta, K; Oyama, Y; Sakuda, M; Totsuka, Y; Suzuki, A T; Hasegawa, M; Hayashi, K; Inagaki, T; Kato, I; Maesaka, H; Morita, T; Nakaya, T; Nishikawa, K; Sasaki, T; Ueda, S; Yamamoto, S; Haines, T J; Dazeley, S; Hatakeyama, S; Svoboda, R; Blaufuss, E; Goodman, J A; Guillian, G; Sullivan, G W; Turcan, D; Scholberg, K; Habig, A; Ackermann, M; Jung, C K; Kato, T; Kobayashi, K; Martens, K; Malek, M; Mauger, C; McGrew, C; Sharkey, E; Viren, B; Yanagisawa, C; Toshito, T; Mitsuda, C; Miyano, K; Shibata, T; Ishii, J; Kajiyama, Y; Kuno, Y; Nagashima, Y; Takita, M; Yoshida, M; Kim, H I; Kim, S B; Yoo, J; Okazawa, H; Ishizuka, T; Choi, Y; Seo, H K; Gando, Y; Hasegawa, T; Inoue, K; Shirai, J; Suzuki, A; Koshiba, M; Hashimoto, T; Nakajima, Y; Nishijima, K; Ishino, H; Morii, M; Nishimura, R; Watanabe, Y; Kielczewska, D; Zalipska, J; Gran, R; Shiraishi, K K; Washburn, K; Wilkes, R J

    2004-07-09

    A search for a nonzero neutrino magnetic moment has been conducted using 1496 live days of solar neutrino data from Super-Kamiokande-I. Specifically, we searched for distortions to the energy spectrum of recoil electrons arising from magnetic scattering due to a nonzero neutrino magnetic moment. In the absence of a clear signal, we found micro(nu)neutrino oscillation on the shapes of energy spectra. With additional information from other solar neutrino and KamLAND experiments constraining the oscillation region, a limit of micro(nu)

  1. Solar Neutrino Oscillation Parameters after KamLAND

    CERN Document Server

    Goswami, S; Choubey, S; Goswami, Srubabati; Bandyopadhyay, Abhijit; Choubey, Sandhya

    2003-01-01

    We explore the impact of the data from the KamLAND experiment in constraining neutrino mass and mixing angles involved in solar neutrino oscillations. In particular we discuss the precision with which we can determine the the mass squared difference $\\Delta m^2_{solar}$ and the mixing angle $\\theta_{solar}$ from combined solar and KamLAND data. We show that the precision with which $\\Delta m^_{solar}$ can be determined improves drastically with the KamLAND data but the sensitivity of KamLAND to the mixing angle is not as good. We study the effect of enhanced statistics in KamLAND as well as reduced systematics in improving the precision. We also show the effect of the SNO salt data in improving the precision. Finally we discuss how a dedicated reactor experiment with a baseline of 70 km can improve the $\\theta_{solar}$ sensitivity by a large amount.

  2. Measurement of the solar neutrino energy spectrum using neutrino-electron scattering

    CERN Document Server

    Fukuda, Y; Ichihara, E; Inoue, K; Ishihara, K; Ishino, H; Itow, Y; Kajita, T; Kameda, J; Kasuga, S; Kobayashi, K; Kobayashi, Y; Koshio, Y; Miura, M; Nakahata, M; Nakayama, S; Okada, A; Okumura, K; Sakurai, N; Shiozawa, M; Suzuki, Y; Takeuchi, Y; Totsuka, Y; Yamada, S; Earl, M; Habig, A; Kearns, E; Messier, M D; Scholberg, K; Stone, J L; Sulak, L R; Walter, C W; Goldhaber, M; Barszczak, T; Casper, D; Gajewski, W; Halverson, P G; Hsu, J; Kropp, W R; Price, R L; Reines, F; Smy, M B; Sobel, H W; Vagins, M R; Ganezer, K S; Keig, W E; Ellsworth, R W; Tasaka, S; Flanagan, J W; Kibayashi, A; Learned, J G; Matsuno, S; Stenger, V J; Takemori, D; Ishii, T; Kanzaki, J; Kobayashi, T; Mine, S; Nakamura, K; Nishikawa, K; Oyama, Y; Sakai, A; Sakuda, M; Sasaki, O; Echigo, S; Kohama, M; Suzuki, A T; Haines, T J; Blaufuss, E; Kim, B K; Sanford, R; Svoboda, R; Chen, M L; Conner, Z; Goodman, J A; Sullivan, G W; Hill, J; Jung, C K; Martens, K; Mauger, C; McGrew, C; Sharkey, E; Viren, B; Yanagisawa, C; Doki, W; Miyano, K; Okazawa, H; Saji, C; Takahata, M; Nagashima, Y; Takita, M; Yamaguchi, T; Yoshida, M; Kim, S B; Etoh, M; Fujita, K; Hasegawa, A; Hasegawa, T; Hatakeyama, S; Iwamoto, T; Koga, M; Maruyama, T; Ogawa, H; Shirai, J; Suzuki, A; Tsushima, F; Koshiba, M; Nemoto, M; Nishijima, K; Futagami, T; Hayato, Y; Kanaya, Y; Kaneyuki, K; Watanabe, Y; Kielczewska, D; Doyle, R A; George, J S; Stachyra, A L; Wai, L L; Wilkes, R J; Young, K K

    1999-01-01

    A measurement of the energy spectrum of recoil electrons from solar neutrino scattering in the Super--Kamiokande detector is presented. The results shown here are obtained from 504 days of data taken between the 31st of May, 1996 and the 25th of March, 1998. The shape of the measured spectrum is compared with the expectation for solar B8 neutrinos. The comparison takes into account both kinematic and detector related effects in the measurement process. The spectral shape comparison between the observation and the expectation gives a chi-square of 25.3 with 15 degrees of freedom, corresponding to a 4.6% confidence level.

  3. The charged current neutrino cross section for solar neutrinos, and background to \\BBz\\ experiments

    CERN Document Server

    Ejiri, H

    2013-01-01

    Solar neutrinos can interact with the source isotope in neutrinoless double beta decay experiments through charged current and neutral current interactions. The charged-current product nucleus will then beta decay with a Q-value larger than the double beta decay Q-value. As a result, this process can populate the region of interest and be a background to the double beta decay signal. In this paper we estimate the solar neutrino capture rates on three commonly used double beta decay isotopes, \

  4. Correlative Aspects of the Solar Electron Neutrino Flux and Solar Activity

    Science.gov (United States)

    Wilson, Robert M.

    2000-01-01

    Between 1970 and 1994, the Homestake Solar Neutrino Detector obtained 108 observations of the solar electron neutrino flux (less than 0.814 MeV). The "best fit" values derived from these observations suggest an average daily production rate of about 0.485 Ar-37 atom per day, a rate equivalent to about 2.6 SNU (solar neutrino units) or about a factor of 3 below the expected rate from the standard solar model. In order to explain, at least, a portion of this discrepancy, some researchers have speculated that the flux of solar neutrinos is variable, possibly being correlated with various markers of the solar cycle (e.g., sunspot number, the Ap index, etc.). In this paper, using the larger "standard data set," the issue of correlative behavior between solar electron neutrino flux and solar activity is re-examined. The results presented here clearly indicate that no statistically significant association exists between any of the usual markers of solar activity and the solar electron neutrino flux.

  5. Combined Analysis of all Three Phases of Solar Neutrino Data from the Sudbury Neutrino Observatory

    CERN Document Server

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

    2011-01-01

    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 a...

  6. Effects of Environment Dependence of Neutrino Mass versus Solar and Reactor Neutrino Data

    CERN Document Server

    González-Garciá, M C; Zukanovich-Funchal, R

    2006-01-01

    In this work we study the phenomenological consequences of the environment dependence of neutrino mass on solar and reactor neutrino phenomenology. Such dependence can be induced, for example, by Yukawa interactions with a light scalar particle which couples to neutrinos and matter and it is expected, among others, in mass varying neutrino scenarios. Under the assumption of one mass scale dominance, we perform a global analysis of solar and KamLAND neutrino data which depends on 4 parameters: the two standard oscillation parameters, Delta m^2 and tan^2(theta), and two new coefficients, which parameterize the environment dependence of the neutrino mass. We find that, generically, the inclusion of the environment dependent terms does not lead to a very statistically significant improvement on the description of the data in the most favoured MSW LMA (or LMA-I) region. It does, however, substantially improve the fit in the high-Delta m^2 LMA (or LMA-II) region which can be allowed at 98.9% CL. Conversely the anal...

  7. Testing solar lepton mixing sum rules in neutrino oscillation experiments

    CERN Document Server

    Ballett, Peter; Luhn, Christoph; Pascoli, Silvia; Schmidt, Michael A

    2014-01-01

    Small discrete family symmetries such as S4, A4 or A5 may lead to simple leading-order predictions for the neutrino mixing matrix such as the bimaximal, tribimaximal or golden ratio mixing patterns, which may be brought into agreement with experimental data with the help of corrections from the charged-lepton sector. Such scenarios generally lead to relations among the parameters of the physical leptonic mixing matrix known as solar lepton mixing sum rules. In this article, we present a simple derivation of such solar sum rules, valid for arbitrary neutrino and charged lepton mixing angles and phases, assuming only {\\theta}13^{\

  8. Precise Measurement of Solar Neutrino Oscillation Parameters from Recent Experiments

    Institute of Scientific and Technical Information of China (English)

    YANG Ping; LIU Qiu-Yu

    2009-01-01

    We analyse the available data of solar neutrino experiments up to the date May 2008,including SK-I,SK-II,SNO phase-I,SNO phase-II and first-generation Ga and C1 experiments.They show great improvement in constraints on solar neutrino oscillation parameters.Together with the new results from long base line reactor experiment KamLAND,the parameters are precisely determined,with la allowed region in △m212 = 7 586+0.212-0.203×10-5 eV2,tan2 θ12=0.457+0.076-0.067

  9. Is bi-maximal mixing compatible with the large angle MSW solution of the solar neutrino problem?

    OpenAIRE

    1998-01-01

    It is shown that the large angle MSW solution of the solar neutrino problem with a bi-maximal neutrino mixing matrix implies an energy-independent suppression of the solar nu_e flux. The present solar neutrino data exclude this solution of the solar neutrino problem at 99.6% CL.

  10. A comment on the suspected solar neutrino -- solar activity connection

    Science.gov (United States)

    Wilson, Robert M.

    1994-01-01

    Recently, it has been proposed that there exists a highly statistically significant (at greater than or equal to 98% level of confidence) relationship between Ar-37 production rate (namely, solar neutrinos) and the Ap geomagnetic index (namely, solar particles), based on the chi-square goodness-of-fit test and correlation analysis, for the interval 1970-1990. While a relationship between the two parameters, indeed, seems to be discernible, the strength of the relationship has been overstated. Instead of being significant at the afore-mentioned level of confidence, the relationship is found to be significant at only greater than or equal to 95% level of confidence, based on Yates' modification to the chi-square test for 2 x 2 contingency tables. Likewise, while correlation analysis yields a value of r = 0.2691, it is important to note that such a value suggests that only about 7% of the variance can be 'explained' by the inferred correlation and that the remaining 93% of the variance must be attributed to other sources.

  11. Constraints on neutrino oscillation parameters from the SNO salt phase data

    Energy Technology Data Exchange (ETDEWEB)

    Bandyopadhyay, Abhijit; Choubey, Sandhya; Goswami, Srubabati; Petcov, S.T.; Roy, D.P

    2004-03-11

    The physics implications of the just published salt phase data from the SNO experiment are examined. The effect of these data on the allowed ranges of the solar neutrino oscillation parameters, {delta}m{sub 21}{sup 2} and sin{sup 2}{theta}{sub 12}, are studied in the cases of two- and three-neutrino mixing. In the latter case we derive an upper limit on the angle {theta}{sub 13}. Constraints on the solar {nu}{sub e} transitions into a mixture of active and sterile neutrinos are also presented. Finally, we give predictions for the day-night asymmetry in the SNO experiment, for the event rate in the BOREXINO and LowNu experiments, and discuss briefly the constraints on the solar neutrino oscillation parameters which can be obtained with prospective KamLAND data.

  12. The Lma MSW Solution of the Solar Neutrino Problem, Inverted Neutrino Mass Hierarchy and Reactor Neutrino Experiments

    CERN Document Server

    Petcov, S T

    2002-01-01

    In the context of three-neutrino oscillations, we study the possibility of using antineutrinos from nuclear reactors to explore the $10^-4 eV^2 < \\Delta m^2_{\\odot} \\ltap 8\\times 10^-4 eV^2$ region of the LMA MSW solution of the solar neutrino problem. The KamLAND experiment is not expected to determine $\\Delta m^2_{\\odot}$ if the latter happens to lie in the indicated region. By analysing both the total event rate suppression and the energy spectrum distortion caused by $\\bar{\

  13. Detecting the upturn of the solar {sup 8}B neutrino spectrum with LENA

    Energy Technology Data Exchange (ETDEWEB)

    Möllenberg, R., E-mail: randolph.moellenberg@ph.tum.de [Excellence Cluster Universe, Technische Universität München, 85748 Garching (Germany); Feilitzsch, F. von; Hellgartner, D.; Oberauer, L.; Tippmann, M. [Physik Department, Technische Universität München, 85748 Garching (Germany); Winter, J.; Wurm, M. [Institut für Physik, Excellence Cluster PRISMA, Johannes Gutenberg Universität Mainz, 55128 Mainz (Germany); Zimmer, V. [Physik Department, Technische Universität München, 85748 Garching (Germany)

    2014-10-07

    LENA (Low Energy Neutrino Astronomy) has been proposed as a next generation 50 kt liquid scintillator detector. The large target mass allows a high precision measurement of the solar {sup 8}B neutrino spectrum, with an unprecedented energy threshold of 2 MeV. Hence, it can probe the MSW-LMA prediction for the electron neutrino survival probability in the transition region between vacuum and matter-dominated neutrino oscillations. Based on Monte Carlo simulations of the solar neutrino and the corresponding background spectra, it was found that the predicted upturn of the solar {sup 8}B neutrino spectrum can be detected with 5σ significance after 5 years.

  14. Detecting the Upturn of the Solar $^8$B Neutrino Spectrum with LENA

    CERN Document Server

    Möllenberg, Randolph; Hellgartner, Dominikus; Oberauer, Lothar; Tippmann, Marc; Winter, Jürgen; Wurm, Michael; Zimmer, Vincenz

    2014-01-01

    LENA (Low Energy Neutrino Astronomy) has been proposed as a next generation 50 kt liquid scintillator detector. The large target mass allows a high precision measurement of the solar $^8$B neutrino spectrum, with an unprecedented energy threshold of 2 MeV. Hence, it can probe the MSW-LMA prediction for the electron neutrino survival probability in the transition region between vacuum and matter-dominated neutrino oscillations. Based on Monte Carlo simulations of the solar neutrino and the corresponding background spectra, it was found that the predicted upturn of the solar $^8$B neutrino spectrum can be detected with 5 sigma significance after 5 y.

  15. Detecting the upturn of the solar 8B neutrino spectrum with LENA

    Directory of Open Access Journals (Sweden)

    R. Möllenberg

    2014-10-01

    Full Text Available LENA (Low Energy Neutrino Astronomy has been proposed as a next generation 50 kt liquid scintillator detector. The large target mass allows a high precision measurement of the solar 8B neutrino spectrum, with an unprecedented energy threshold of 2 MeV. Hence, it can probe the MSW-LMA prediction for the electron neutrino survival probability in the transition region between vacuum and matter-dominated neutrino oscillations. Based on Monte Carlo simulations of the solar neutrino and the corresponding background spectra, it was found that the predicted upturn of the solar 8B neutrino spectrum can be detected with 5σ significance after 5 years.

  16. Search For Non-zero Neutrino Magnetic Moments Using Super-kamiokande-i Solar Neutrino Data

    CERN Document Server

    Liu, D

    2005-01-01

    Non-zero neutrino magnetic moments would mean new physics beyond the standard model. Therefore a search for a nonzero neutrino magnetic moment has been conducted using the high statistic 1496 live day solar neutrino data from Super-Kamiokande-I. The search looked for distortions to the energy spectrum of recoil electrons from ν-e elastic scattering. A nonzero neutrino magnetic moment would cause an increase of event rates at lower energies. In the absence of clear signal, we found μν ≤ 3.6 × 10−10 μB at 90% C.L. by fitting to the Super-Kamiokande (Super-K) day/night energy spectra. The fitting took into account the effect of neutrino oscillations on the shape of energy spectra. With the results from other neutrino experiments constraining the oscillation parameter region, a limit of μν ≤ 1.1 × 10 −10 μB at 90% C.L. was obtained.

  17. Reviving the energy independent suppression of the solar neutrino flux

    CERN Document Server

    Choubey, S; Gupta, N; Roy, D P; Choubey, Sandhya; Goswami, Srubabati; Gupta, Nayantara

    2001-01-01

    We explore the possibility of an energy independent suppression of the solar neutrino flux in the context of the recent SuperKamiokande data. From a global analysis of the rate and spectrum data, this scenario is allowed at only 14% probability with the observed Cl rate. If we allow for a 20% upward renormalisation of the Cl rate along with a downward renormalisation of the $B$ neutrino flux then the fit improves considerably to a probability of $\\sim 50%$. We compare the quality of these fits with those of the MSW solutions. These renormalisations are also found to improve the quality of the fits with MSW solutions and enlarge the allowed region of their validity in the parameter space substantially. Over much of this enlarged region the matter effects on the suppression of the solar neutrino flux are found to be very weak, so that the solutions become practically energy independent.

  18. What do we (not) know theoretically about solar neutrino fluxes?

    Science.gov (United States)

    Bahcall, John N; Pinsonneault, M H

    2004-03-26

    Solar model predictions of 8B and p-p neutrinos agree with the experimentally determined fluxes (including oscillations): phi(pp)(measured)=(1.02+/-00.02+/-0.01)phi(pp)(theory) and phi(8B)(measured)=(0.88+/-0.04+/-0.23)phi(8B)(theory), 1sigma experimental and theoretical uncertainties, respectively. We use improved input data for nuclear fusion reactions, the equation of state, and the chemical composition of the Sun. The solar composition is the dominant uncertainty in calculating the 8B and CNO neutrino fluxes; the cross section for the 3He(4He,gamma)7Be reaction is the most important uncertainty for the calculated 7Be neutrino flux.

  19. Solar neutrino measurements in Super-Kamiokande-II

    CERN Document Server

    Cravens, J P; Iida, T; Ishihara, K; Kameda, J; Koshio, Y; Minamino, A; Mitsuda, C; Miura, M; Moriyama, S; Nakahata, M; Nakayama, S; Obayashi, Y; Ogawa, H; Sekiya, H; Shiozawa, M; Suzuki, Y; Takeda, A; Takeuchi, Y; Ueshima, K; Watanabe, H; Yamada, S; Higuchi, I; Ishihara, C; Ishitsuka, M; Kajita, T; Kaneyuki, K; Mitsuka, G; Nishino, H; Okumura, K; Saji, C; Takenaga, Y; Clark, S; Desai, S; Dufour, F; Kearns, E; Likhoded, S; Litos, M; Raaf, Jennifer L; Stone, J L; Sulak, L R; Wang, W; Goldhaber, M; Casper, D; Dunmore, J; Kropp, W R; Liu, D W; Mine, S; Regis, C; Smy, M B; Sobel, H W; Vagins, M R; Ganezer, K S; Hill, J; Keig, W E; Jang, J S; Kim, J Y; Lim, I T; Fechner, M; Scholberg, K; Tanimoto, N; Walter, C W; Wendell, R; Ellsworth, R W; Tasaka, S; Guillian, G; Learned, J G; Matsuno, S; Messier, M D; Watanabe, Y; Hayato, Y; Ichikawa, A K; Ishida, T; Ishii, T; Iwashita, T; Kobayashi, T; Nakadaira, T; Nakamura, K; Nitta, K; Oyama, Y; Totsuka, Y; Suzuki, A T; Hasegawa, M; Hiraide, K; Kato, I; Maesaka, H; Nakaya, T; Nishikawa, K; Sasaki, T; Sato, H; Yamamoto, S; Yokoyama, M; Haines, T J; Dazeley, S; Hatakeyama, S; Svoboda, R; Sullivan, G W; Turcan, D; Habig, A; Fukuda, Y; Sato, T; Itow, Y; Koike, T; Tanaka, T; Jung, C K; Kato, T; Kobayashi, K; Malek, M; McGrew, C; Sarrat, A; Terri, R; Yanagisawa, C; Tamura, N; Idehara, Y; Ikeda, M; Sakuda, M; Sugihara, M; Kuno, Y; Yoshida, M; Kim, S B; Yang, B S; Yoo, J; Ishizuka, T; Okazawa, H; Choi, Y; Seo, H K; Gando, Y; Hasegawa, T; Inoue, K; Furuse, Y; Ishii, H; Nishijima, K; Ishino, H; Koshiba, M; Chen, S; Deng, Z; Liu, Y; Kielczewska, D; Berns, H; Gran, R; Shiraishi, K K; Stachyra, A; Thrane, E; Washburn, K; Wilkes, R J

    2008-01-01

    The results of the second phase of the Super-Kamiokande solar neutrino measurement are presented and compared to the first phase. The solar neutrino flux spectrum and time-variation as well as oscillation results are statistically consistent with the first phase and do not show spectral distortion. The time-dependent flux measurement of the combined first and second phases coincides with the full period of solar cycle 23 and shows no correlation with solar activity. The measured boron 8 total flux is 2.38 +/-0.05(stat.) +0.16-0.15(sys.) X 10^6 cm^-2 sec^-1 and the day-night difference is found to be -6.3 +/-4.2(stat.) +/-3.7(sys.) %. There is no evidence of systematic tendencies between the first and second phases.

  20. Solar Neutrinos with Magnetic Moment Rates and Global Analysis

    CERN Document Server

    Pulido, J

    2002-01-01

    A statistical analysis of the solar neutrino data is presented assuming the solar neutrino deficit to be resolved by the resonant interaction of the neutrino magnetic moment with the solar magnetic field. Four field profiles are investigated, all exhibiting a rapid increase across the bottom of the convective zone, one of them closely following the requirements from recent solar physics investigations. First a 'rates only' analysis is performed whose best fits appear to be remarkably better than all fits from oscillations. A global analysis then follows with the corresponding best fits of a comparable quality to the LMA one. Despite the fact that the resonant spin flavour precession does not predict any day/night effect, the separate SuperKamiokande day and night data are included in the analysis in order to allow for a direct comparison with oscillation scenarios. Remarkably enough, the best fit for rates and global analysis which is compatible with most astrophysical bounds on the neutrino magnetic moment i...

  1. Non-Standard Models, Solar Neutrinos, and Large \\theta_{13}

    CERN Document Server

    Bonventre, R; Klein, J R; Gann, G D Orebi; Seibert, S; Wasalski, O

    2013-01-01

    Solar neutrino experiments have yet to see directly the transition region between matter-enhanced and vacuum oscillations. The transition region is particularly sensitive to models of non-standard neutrino interactions and propagation. We examine several such non-standard models, which predict a lower-energy transition region and a flatter survival probability for the ^{8}B solar neutrinos than the standard large-mixing angle (LMA) model. We find that while some of the non-standard models provide a better fit to the solar neutrino data set, the large measured value of \\theta_{13} and the size of the experimental uncertainties lead to a low statistical significance for these fits. We have also examined whether simple changes to the solar density profile can lead to a flatter ^{8}B survival probability than the LMA prediction, but find that this is not the case for reasonable changes. We conclude that the data in this critical region is still too poor to determine whether any of these models, or LMA, is the bes...

  2. Projected performance of a large superfluid helium solar neutrino detector

    Energy Technology Data Exchange (ETDEWEB)

    Bandler, S.R.; Enss, C.; Goldhaber, G.; Lanou, R.E.; Maris, H.J.; More, T.; Porter, F.S.; Seidel, G.M. (Brown Univ., Providence, RI (United States))

    1993-11-01

    Based upon experiments carried out using radioactive sources to investigate the particle detection properties of superfluid helium the authors project a configuration for and the response of a full scale detector for solar neutrinos employing the roton/quantum evaporation technique.

  3. Search for radiative decays of solar neutrinos during a solar eclipse

    CERN Document Server

    Giacomelli, G

    2001-01-01

    A search for possible radiative decays of solar neutrinos with emission of photons in the visible range may be performed during total solar eclipses. We discuss some results obtained from the digitized images recorded during the August 11, 1999 total solar eclipse in Romania, and report on the observations made in June 21, 2001, in Zambia.

  4. Reconciling cold dark matter with COBE/IRAS plus solar and atmospheric neutrino data

    CERN Document Server

    Joshipura, A S; Joshipura, A S; Valle, J W F

    1994-01-01

    We present a model where an unstable MeV Majorana tau neutrino can naturally reconcile the cold dark matter model (CDM) with cosmological observations of large and small scale density fluctuations and, simultaneously, with data on solar and atmospheric neutrinos. The solar neutrino deficit is explained through long wavelength, so-called {\\sl just-so} oscillations involving conversions of \

  5. Search for possible solar neutrino radiative decays during total solar eclipses

    CERN Document Server

    Cecchini, S; Giacomelli, G; Giacomelli, R; Popa, V

    2006-01-01

    Total solar eclipses (TSEs) offer a good opportunity to look for photons produced in possible radiative decays of solar neutrinos. In this paper we briefly review the physics bases of such searches as well as the existing limits on the neutrino proper lifetimes obtained by such experiments. We the report on the observations performed in occasion of the 29 March 2006 TSE, from Waw an Namos, Libya.

  6. ecCNO Solar Neutrinos: A Challenge for Gigantic Ultra-Pure Liquid Scintillator Detectors

    CERN Document Server

    Villante, F L

    2014-01-01

    Neutrinos produced in the Sun by electron capture reactions on $^{13}{\\rm N}$, $^{15}{\\rm O}$ and $^{17}{\\rm F}$, to which we refer as ecCNO neutrinos, are not usually considered in solar neutrino analysis since the expected fluxes are extremely low. The experimental determination of this sub-dominant component of the solar neutrino flux is very difficult but could be rewarding since it provides a determination of the metallic content of the solar core and, moreover, probes the solar neutrino survival probability in the transition region at $E_\

  7. Equivalence Principle from the Solar and Reactor Neutrino Observations

    Energy Technology Data Exchange (ETDEWEB)

    Valdiviesso, G.A., E-mail: gamaral@ifi.unicamp.br [Instituto de Fisica Gleb Wataghin, Universidade Estadual de Campinas, UNICAMP, Rua Sergio Buarque de Holanda, 777, 13083-859 Campinas SP Brazil (Brazil); Guzzo, M.M., E-mail: guzzo@ifi.unicamp.br [Instituto de Fisica Gleb Wataghin, Universidade Estadual de Campinas, UNICAMP, Rua Sergio Buarque de Holanda, 777, 13083-859 Campinas SP Brazil (Brazil); Holanda, P.C., E-mail: holanda@ifi.unicamp.br [Instituto de Fisica Gleb Wataghin, Universidade Estadual de Campinas, UNICAMP, Rua Sergio Buarque de Holanda, 777, 13083-859 Campinas SP Brazil (Brazil)

    2012-08-15

    A model for the Violation of the Equivalence Principle (VEP) on solar and reactor neutrinos is investigated, and a new limit for the VEP is obtained considering the mass-flavor mixing hypothesis and the VEP model. Our analysis showed that due to the effects on {nu}{sub e} and {nu}{sup Macron }{sub e} disapearance channels, VEP effects can be at most of 1 part in 10{sup 14}, assuming that neutrinos are mainly affected by the gravitational potential due to the Great Atractor.

  8. Nuclear processes and neutrino production in solar flares

    Science.gov (United States)

    Lingenfelter, R. E.; Ramaty, R.; Murphy, R. J.; Kozlovsky, S.

    1985-01-01

    The determination of flare neutrino flux is approached from the standpoint of recent observations and theoretical results on the nuclear processes in solar flares. Attention is given to the energy spectra and total numbers of accelerated particles in flares, as well as their resulting production of beta(+)-emitting radionuclei and pions; these should be the primary sources of neutrinos. The observed 0.511 MeV line flux for the June 21, 1980 flare is compared with the expected from the number and spectrum of accelerated particles.

  9. Complete results for five years of GNO solar neutrino observations

    OpenAIRE

    Altmann, M; Balata, M.; Belli, P.; Bellotti, E.(Dipartimento di Fisica, Università Milano Bicocca, Milan, Italy); Bernabei, R.; Burkert, E; Cattadori, C.; Cerulli, R.; Chiarini, M; Cribier, M.; D'Angelo, S; Del Re, G.; Ebert, K.; Feilitzsch, F; Ferrari, N.

    2005-01-01

    We report the complete GNO solar neutrino results for the measuring periods GNO III, GNO II, and GNO I. The result for GNO III (last 15 solar runs) is [54.3 + 9.9 - 9.3 (stat.)+- 2.3 (syst.)] SNU (1 sigma) or [54.3 + 10.2 - 9.6 (incl. syst.)] SNU (1 sigma) with errors combined. The GNO experiment is now terminated after altogether 58 solar exposure runs that were performed between May 20, 1998 and April 9, 2003. The combined result for GNO (I+II+III) is [62.9 + 5.5 - 5.3 (stat.) +- 2.5 (syst....

  10. Neutrino flavor ratios as diagnostic of solar WIMP annihilation

    CERN Document Server

    Lehnert, Ralf

    2007-01-01

    We consider the neutrino (and antineutrino) flavors arriving at Earth for neutrinos produced in the annihilation of weakly interacting massive particles (WIMPs) in the Sun's core. Solar-matter effects on the flavor propagation of the resulting $\\agt$ GeV neutrinos are studied analytically within a density-matrix formalism. Matter effects, including mass-state level-crossings, influence the flavor fluxes considerably. The exposition herein is somewhat pedagogical, in that it starts with adiabatic evolution of single flavors from the Sun's center, with $\\theta_{13}$ set to zero, and progresses to fully realistic processing of the flavor ratios expected in WIMP decay, from the Sun's core to the Earth. In the fully realistic calculation, non-adiabatic level-crossing is included, as are possible nonzero values for $\\theta_{13}$ and the CP-violating phase $\\delta$. Due to resonance enhancement in matter, nonzero values of $\\theta_{13}$ even smaller than a degree can noticeably affect flavor propagation. Both normal...

  11. Neutrino flavor ratios as diagnostic of solar WIMP annihilation

    Science.gov (United States)

    Lehnert, Ralf; Weiler, Thomas J.

    2008-06-01

    We consider the neutrino (and antineutrino) flavors arriving at the Earth for neutrinos produced in the annihilation of weakly interacting massive particles (WIMPs) in the sun’s core. Solar-matter effects on the flavor propagation of the resulting ≳GeV neutrinos are studied analytically within a density-matrix formalism. Matter effects, including mass-state level crossings, influence the flavor fluxes considerably. The exposition herein is somewhat pedagogical, in that it starts with adiabatic evolution of single flavors from the sun’s center, with θ13 set to zero, and progresses to fully realistic processing of the flavor ratios expected in WIMP decay, from the sun’s core to the Earth. In the fully realistic calculation, nonadiabatic level crossing is included, as are possible nonzero values for θ13 and the CP-violating phase δ. Because of resonance enhancement in matter, nonzero values of θ13 even smaller than a degree can noticeably affect flavor propagation. Both normal and inverted neutrino-mass hierarchies are considered. Our main conclusion is that measuring flavor ratios (in addition to energy spectra) of ≳GeV solar neutrinos can provide discrimination between WIMP models. In particular, we demonstrate the flavor differences at the Earth for neutrinos from the two main classes of WIMP final states, namely W+W- and 95%bb¯+5%τ+τ-. Conversely, if WIMP properties were to be learned from production in future accelerators, then the flavor ratios of ≳GeV solar neutrinos might be useful for inferring θ13 and the mass hierarchy. From the full calculations, we find (and prove) some general features: a flavor-democratic flux produced at the sun’s core arrives at the Earth still flavor democratic; for maximal θ32 but arbitrary θ21 and θ13, the replacement δ→π-δ leaves the νe flavor spectra unaltered but interchanges νμ and ντ spectra at the Earth; and, only for neutrinos in the inverted hierarchy and antineutrinos in the normal

  12. Combined effect of NSI and SFP on solar electron neutrino oscillation

    CERN Document Server

    Yilmaz, Deniz

    2016-01-01

    The combined effect of SFP and the non standard neutrino interaction (NSI) on the survival probability of solar electron neutrinos (assumed to be Dirac particles) is examined for various values of $\\epsilon_{11}$, $\\epsilon_{12}$ and $\\mu B$. It is found that the neutrino survival probability curves affected by SFP and NSI effects individually for some values of the parameters ($\\epsilon_{11}$, $\\epsilon_{12}$ and $\\mu B$) get close to the standard MSW curve when both effects are combined. Therefore, the combined effect of SFP and NSI needs to be taken into account when the solar electron neutrino data obtained by low energy solar neutrino experiments is investigated.

  13. Data analysis for solar neutrinos observed by water Cherenkov detectors{sup *}

    Energy Technology Data Exchange (ETDEWEB)

    Koshio, Yusuke [Okayama University, Okayama (Japan)

    2016-04-15

    A method of analyzing solar neutrino measurements using water-based Cherenkov detectors is presented. The basic detection principle is that the Cherenkov photons produced by charged particles via neutrino interaction are observed by photomultiplier tubes. A large amount of light or heavy water is used as a medium. The first detector to successfully measure solar neutrinos was Kamiokande in the 1980's. The next-generation detectors, i.e., Super-Kamiokande and the Sudbury Neutrino Observatory (SNO), commenced operation from the mid-1990's. These detectors have been playing the critical role of solving the solar neutrino problem and determining the neutrino oscillation parameters over the last decades. The future prospects of solar neutrino analysis using this technique are also described. (orig.)

  14. Reanalysis of the GALLEX solar neutrino flux and source experiments

    Energy Technology Data Exchange (ETDEWEB)

    Kaether, F., E-mail: Florian.Kaether@mpi-hd.mpg.d [Max Planck Institute for Nuclear Physics, P.O. Box 103980, D-69029 Heidelberg (Germany); Hampel, W.; Heusser, G.; Kiko, J.; Kirsten, T. [Max Planck Institute for Nuclear Physics, P.O. Box 103980, D-69029 Heidelberg (Germany)

    2010-02-22

    After the completion of the gallium solar neutrino experiments at the Laboratori Nazionali del Gran Sasso (GALLEX: 1991-1997; GNO: 1998-2003) we have retrospectively updated the GALLEX results with the help of new technical data that were impossible to acquire for principle reasons before the completion of the low rate measurement phase (that is, before the end of the GNO solar runs). Subsequent high rate experiments have allowed the calibration of absolute internal counter efficiencies and of an advanced pulse shape analysis for counter background discrimination. The updated overall result for GALLEX (only) is 73.4{sub -7.3}{sup +7.1} SNU. This is 5.3% below the old value of 77.5{sub -7.8}{sup +7.5} SNU (GALLEX Collaboration, W. Hampel et al., 1999 ), with a substantially reduced error. A similar reduction is obtained from the reanalysis of the {sup 51}Cr neutrino source experiments of 1994/1995.

  15. Reanalysis of the GALLEX solar neutrino flux and source experiments

    CERN Document Server

    Kaether, F; Heusser, G; Kiko, J; Kirsten, T; 10.1016/j.physletb.2010.01.030

    2010-01-01

    After the completion of the gallium solar neutrino experiments at the Laboratori Nazionali del Gran Sasso (GALLEX}: 1991-1997; GNO: 1998-2003) we have retrospectively updated the GALLEX results with the help of new technical data that were impossible to acquire for principle reasons before the completion of the low rate measurement phase (that is, before the end of the GNO solar runs). Subsequent high rate experiments have allowed the calibration of absolute internal counter efficiencies and of an advanced pulse shape analysis for counter background discrimination. The updated overall result for GALLEX (only) is (73.4 +7.1 -7.3) SNU. This is 5.3% below the old value of (77.5 + 7.5 -7.8) SNU (PLB 447 (1999) 127-133) with a substantially reduced error. A similar reduction is obtained from the reanalysis of the 51Cr neutrino source experiments of 1994/1995.

  16. g-modes and the solar neutrino problem

    Science.gov (United States)

    Bahcall, John N.; Kumar, Pawan

    1993-01-01

    We show that low-order g-modes with large enough amplitudes to affect significantly the solar neutrino fluxes would produce surface velocities that are 10 exp 4 times larger than the observed upper limits and hence are ruled out by existing data. We also demonstrate that any large-amplitude, short-period oscillations that grow on a Kelvin-Helmholtz time scale will require, to affect solar neutrino fluxes, a large amount of energy (for g-modes, 10 exp 9 times the energy in the observed p-mode oscillations) and a tiny amount of dissipation (for g modes, 10 exp -8 the fractional dissipation rate of the p-modes).

  17. Neutrino Oscillation Parameters After High Statistics KamLAND Results

    CERN Document Server

    Bandyopadhyay, Abhijit; Goswami, Srubabati; Petcov, S T; Roy, D P

    2008-01-01

    We do a re-analysis to asses the impact of the results of the Borexino experiment and the recent 2.8 KTy KamLAND data on the solar neutrino oscillation parameters. The current Borexino results are found to have no impact on the allowed solar neutrino parameter space. The new KamLAND data causes a significant reduction of the allowed range of $\\Delta m^2_{21}$, determining it with an unprecedented precision of 8.3% at 3$\\sigma$. The precision of $\\Delta m^2_{21}$ is controlled practically by the KamLAND data alone. Inclusion of new KamLAND results also improves the upper bound on $\\sin^2\\theta_{12}$, but the precision of this parameter continues to be controlled by the solar data. The third mixing angle is constrained to be $\\sin^2\\theta_{13} < 0.063$ at $3\\sigma$ from a combined fit to the solar, KamLAND, atmospheric and CHOOZ results. We also address the issue of how much further reduction of allowed range of $\\Delta m^2_{21}$ and $\\sin^2\\theta_{12}$ is possible with increased statistics from KamLAND. We ...

  18. Reducing the Solar Neutrino Background Using Polarised Helium-3

    CERN Document Server

    Franarin, Tarso

    2016-01-01

    Future dark matter detectors plan to have sensitivities such that solar neutrinos will start to become a problematic background. In this work we show that a polarised helium-3 detector would in principle be able to eliminate 98% of these events when the orientation of the polarisation axis is antiparallel to the direction of the Sun. We comment on the possible improvement in sensitivity of dark matter direct detection experiments due to this effect and the feasibility of building such a detector.

  19. Solar neutrino results in Super-Kamiokande-III

    CERN Document Server

    Abe, K; Iida, T; Ikeda, M; Ishihara, C; Iyogi, K; Kameda, J; Kobayashi, K; Koshio, Y; Kozuma, Y; Miura, M; Moriyama, S; Nakahata, M; Nakayama, S; Obayashi, Y; Ogawa, H; Sekiya, H; Shiozawa, M; Suzuki, Y; Takeda, A; Takenaga, Y; Ueno, K; Ueshima, K; Watanabe, H; Yamada, S; Yokozawa, T; Hazama, S; Kaji, H; Kajita, T; Kaneyuki, K; McLachlan, T; Okumura, K; Shimizu, Y; Tanimoto, N; Vagins, M R; Labarga, L; Magro, L M; Dufour, F; Kearns, E; Litos, M; Raaf, J L; Stone, J L; Sulak, L R; Wang, W; Goldhaber, M; Bays, K; Casper, D; Cravens, J P; Kropp, W R; Mine, S; Regis, C; Renshaw, A; Smy, M B; Sobel, H W; Ganezer, K S; Hill, J; Keig, W E; Jang, J S; Kim, J Y; Lim, I T; Albert, J; Wendell, R; Wongjirad, T; Scholberg, K; Walter, C W; Ishizuka, T; Tasaka, S; Learned, J G; Matsuno, S; Watanabe, Y; Hasegawa, T; Ishida, T; Ishii, T; Kobayashi, T; Nakadaira, T; Nakamura, K; Nishikawa, K; Nishino, H; Oyama, Y; Sakashita, K; Sekiguchi, T; Tsukamoto, T; Suzuki, A T; Takeuchi, Y; Minamino, A; Nakaya, T; Fukuda, Y; Itow, Y; Mitsuka, G; Tanaka, T; Jung, C K; Lopez, G; McGrew, C; Terri, R; Yanagisawa, C; Tamura, N; Ishino, H; Kibayashi, A; Mino, S; Mori, T; Sakuda, M; Toyota, H; Kuno, Y; Yoshida, M; Kim, S B; Yang, B S; Ishizuka, T; Okazawa, H; Choi, Y; Nishijima, K; Yokosawa, Y; Koshiba, M; Totsuka, Y; Yokoyama, M; Chen, S; Heng, Y; Yang, Z; Zhang, H; Kielczewska, D; Mijakowski, P; Connolly, K; Dziomba, M; Thrane, E; Wilkes, R J

    2010-01-01

    The results of the third phase of the Super-Kamiokande solar neutrino measurement are presented and compared to the first and second phase results. With improved detector calibrations, a full detector simulation, and improved analysis methods, the systematic uncertainty on the total neutrino flux is estimated to be ?2.1%, which is about two thirds of the systematic uncertainty for the first phase of Super-Kamiokande. The observed 8B solar flux in the 5.0 to 20 MeV total electron energy region is 2.32+/-0.04 (stat.)+/-0.05 (sys.) *10^6 cm^-2sec^-1, in agreement with previous measurements. A combined oscillation analysis is carried out using SK-I, II, and III data, and the results are also combined with the results of other solar neutrino experiments. The best-fit oscillation parameters are obtained to be sin^2 {\\theta}12 = 0.30+0.02-0.01(tan^2 {\\theta}12 = 0.42+0.04 -0.02) and {\\Delta}m2_21 = 6.2+1.1-1.9 *10^-5eV^2. Combined with KamLAND results, the best-fit oscillation parameters are found to be sin^2 {\\thet...

  20. Solar neutrino measurement in SK and larger detector

    Energy Technology Data Exchange (ETDEWEB)

    Koshio, Y. [Kamioka observatory, ICRR, Univ. of Tokyo, Higashi-Mozumi, Kamioka cho, Hida city, Gifu pref (Japan)

    2005-08-15

    The results of solar neutrino data from the first phase of Super-Kamiokande (SK-I) are presented. Super-Kamiokande can measure not only the solar neutrino flux but also its energy spectrum and time variations such as day-night and seasonal differences. The detail oscillation analysis using those information is appeared. Combining all the solar and KamLAND reactor data, the obtained oscillation parameters are determined as {delta}m{sup 2}=8.3x10{sup -5}eV{sup 2} and tan{sup 2}{theta}=0.38. The recent results in the second phase of SK (SK-II) are also presented, and its flux, spectrum and time variation are consistent with SK-I. The possibility of future water Cherenkov detectors, such as SK-III and Mega-ton class detector, are described. If the current neutrino oscillation parameter is assumed, its spectrum has deficit in the lower energy region. And the possibility of the day-night asymmetry is also discussed.

  1. Measurement of the Solar Neutrino Flux with an Array of Neutron Detectors in the Sudbury Neutrino Observatory

    CERN Document Server

    Jamieson, Blair

    2008-01-01

    The Sudbury Neutrino Observatory has measured the $^8$B solar neutrino flux using an array of 3He proportional counters. Results obtained using a Markov-Chain Monte-Carlo (MCMC) parameter estimation, integrating over a standard extended likelihood, yield effective neutrino fluxes of: phi_nc=5.54+0.33-0.31(stat)+0.36-0.34(syst) x 10^6 /cm^2/s, phi_cc=1.67+0.05-0.04(stat)+0.07-0.08(syst) x 10^6 /cm^2/s, and phi_es=1.77+0.24-0.21(stat)+0.09-0.10(syst) x 10^6 /cm^2/s. These measurements are in agreement with previous solar neutrino flux measurements, and with neutrino oscillation model results. Including these flux measurements in a global analysis of solar and reactor neutrino results yields an improved precision on the solar neutrino mixing angle of theta=34.4+1.3-1.2 degrees, and Delta m^2=7.59+0.19-0.21 eV^2.

  2. Constraining Big Bang lithium production with recent solar neutrino data

    CERN Document Server

    Takács, Marcell P; Szücs, Tamás; Zuber, Kai

    2015-01-01

    The 3He({\\alpha},{\\gamma})7Be reaction affects not only the production of 7Li in Big Bang nucleosynthesis, but also the fluxes of 7Be and 8B neutrinos from the Sun. This double role is exploited here to constrain the former by the latter. A number of recent experiments on 3He({\\alpha},{\\gamma})7Be provide precise cross section data at E = 0.5-1.0 MeV center-of-mass energy. However, there is a scarcity of precise data at Big Bang energies, 0.1-0.5 MeV, and below. This problem can be alleviated, based on precisely calibrated 7Be and 8B neutrino fluxes from the Sun that are now available, assuming the neutrino flavour oscillation framework to be correct. These fluxes and the standard solar model are used here to determine the 3He(alpha,gamma)7Be astrophysical S-factor at the solar Gamow peak, S(23+6-5 keV) = 0.548+/-0.054 keVb. This new data point is then included in a re-evaluation of the 3He({\\alpha},{\\gamma})7Be S-factor at Big Bang energies, following an approach recently developed for this reaction in the c...

  3. Resonant spin-flavor precession constraints on the neutrino parameters and the twisting structure of the solar magnetic fields from the solar neutrino data

    Indian Academy of Sciences (India)

    S Dev; Jyoti Dhar Sharma; U C Pandey; S P Sud; B C Chauhan

    2003-07-01

    Resonant spin-flavor precession (RSFP) scenario with twisting solar magnetic fields has been confronted with the solar neutrino data from various ongoing experiments. The anticorrelation apparent in the Homestake solar neutrino data has been taken seriously to constrain ( 2,') parameter space and the twisting profiles of the magnetic field in the convective zone of the Sun. The twisting profiles, thus derived, have been used to calculate the variation of the neutrino detection rates with the solar magnetic activity for the Homestake, Super-Kamiokande and the gallium experiments. It is found that the presence of twisting reduces the degree of anticorrelation in all the solar neutrino experiments. However, the anticorrelation in the Homestake experiment is expected to be more pronounced in this scenario. Moreover, the anticorrelation of the solar neutrino flux emerging from the southern solar hemisphere is expected to be stronger than that for the neutrinos emerging from the northern solar hemispheres.

  4. Complete results for five years of GNO solar neutrino observations

    CERN Document Server

    Altmann, M; Belli, P; Bellotti, E; Bernabei, R; Burkert, E; Cattadori, C; Cerulli, R; Chiarini, M; Cribier, Michel; D'Angelo, S; Re, G D; Ebert, K H; Feilitzsch, F; Ferrari, N; Hampel, W; Hartmann, F X; Henrich, E; Heusser, G; Kaether, F; Kiko, J; Kirsten, T; Lachenmaier, T; Lanfranchi, J; Laubenstein, M; Luetzenkirchen, K; Mayer, K; Moegel, P; Motta, D; Nisi, S; Oehm, J; Pandola, L; Petricca, F; Potzel, W; Richter, H; Schönert, S; Wallenius, M; Wójcik, M; Zanotti, L

    2005-01-01

    We report the complete GNO solar neutrino results for the measuring periods GNO III, GNO II, and GNO I. The result for GNO III (last 15 solar runs) is [54.3 + 9.9 - 9.3 (stat.)+- 2.3 (syst.)] SNU (1 sigma) or [54.3 + 10.2 - 9.6 (incl. syst.)] SNU (1 sigma) with errors combined. The GNO experiment is now terminated after altogether 58 solar exposure runs that were performed between May 20, 1998 and April 9, 2003. The combined result for GNO (I+II+III) is [62.9 + 5.5 - 5.3 (stat.) +- 2.5 (syst.)] SNU (1 sigma) or [62.9 + 6.0 - 5.9] SNU (1 sigma) with errors combined in quadrature. Overall, gallium based solar observations at LNGS (first in GALLEX, later in GNO) lasted from May 14, 1991 through April 9, 2003. The joint result from 123 runs in GNO and GALLEX is [69.3 +- 5.5 (incl. syst.)] SNU (1 sigma). The distribution of the individual run results is consistent with the hypothesis of a neutrino flux that is constant in time. Implications from the data in particle- and astrophysics are reiterated.

  5. [Variations in the intensity of solar neutrinos as a problem for physical chemistry].

    Science.gov (United States)

    Vladimirskiĭ, B M; Bruns, A V

    2001-01-01

    A comparison of variations in the solar neutrino flux in Brookhaven measurements with solar activity indices clearly shows that the neutrino flux is controlled by surface solar processes. These processes can lead to changes in the efficiency of registrations of the neutrino flux. From this view point, the results of the measurements of the neutrino flux on the Brookhaven detector in 1970-1994 (108 runs) were analyzed. It was found that the neutrino flux depends on the heliogeophysical situation. The well known anticorrelation between the neutrino flux and Wolf numbers is observed only for odd cycle of solar activity. A similar regularity occurs for critical frequencies of E-ionosphere. By contrast, the correlation between the neutrino flux and the Ap-index is observed only for the even activity cycle. The predominance of the sign of radial component of the interplanetary magnetic field in the last 7-14 days of exposure has the greatest effect on the neutrino flux (this sign changes as the sign of the total magnetic field of the Sun changes). In short runs, the neutrino flux changes more than threefold. The conclusion is made that variations of the solar neutrino flux are falcious. These fictitious variations are caused probably by the action of very low-frequency electromagnetic emissions of the magnetosphere upon the substance of the target and the technology of the extraction of 37Ar atoms from perchloretylene.

  6. Solar neutrino interactions with liquid scintillators used for double beta decay experiments

    CERN Document Server

    Ejiri, Hiroyasu

    2016-01-01

    Solar neutrinos interact with double beta decay detectors (DBD) and hence will contribute to backgrounds (BG) for DBD experiments. Background contributions due to solar neutrinos are evaluated for their interactions with atomic electrons and nuclei in liquid scintillation detectors used for DBD experiments. They are shown to be serious backgrounds for high sensitivity DBD experiments to search for the Majorana neutrino masses in the inverted and normal hierarchy regions.

  7. Solar neutrino interactions with liquid scintillators used for double beta-decay experiments

    Science.gov (United States)

    Ejiri, Hiroyasu; Zuber, Kai

    2016-08-01

    Solar neutrinos interact within double-beta-decay (DBD) detectors and hence will contribute to backgrounds (BGs) for DBD experiments. Background contributions due to solar neutrinos are evaluated for their interactions with atomic electrons and nuclei in liquid scintillation detectors used for DBD experiments. They are shown to be serious BGs for high-sensitivity DBD experiments to search for the Majorana neutrino masses in the inverted and normal hierarchy regions.

  8. The effect of random matter density perturbations on the MSW solution to the solar neutrino problem

    CERN Document Server

    Nunokawa, H; Semikoz, V B; Valle, José W F

    1996-01-01

    We consider the implications of solar matter density random noise upon resonant neutrino conversion. The evolution equation describing MSW-like conversion is derived in the framework of the Schr\\"odinger approach. We study quantitatively their effect upon both large and small mixing angle MSW solutions to the solar neutrino problem. This is carried out both for the active-active \

  9. pp-Solar Neutrino Spectroscopy: Return of the Indium Detector

    OpenAIRE

    2001-01-01

    A new indium-loaded liquid scintillator (LS) with up to 15wt% In and high light output promises a breakthrough in the 25y old proposal for observing pp solar neutrinos (nue) by tagged nue capture in 115In. Intense background from the natural beta-decay of In, the single obstacle blocking this project till now, can be reduced by more than x100 with the new In-LS. Only non-In background remains, dramatically relaxing design criteria. Eight tons of In yields ~400 pp nue/y after analysis cuts. Wi...

  10. Evaluation of expected solar flare neutrino events in the IceCube observatory

    CERN Document Server

    de Wasseige, G; Hanson, K; van Eijndhoven, N; Klein, K -L

    2015-01-01

    Since the end of the eighties and in response to a reported increase in the total neutrino flux in the Homestake experiment in coincidence with a solar flare, solar neutrino detectors have searched for solar flare signals. Neutrinos from the decay of mesons, which are themselves produced in collisions of accelerated protons with the solar atmosphere, would provide a novel window on the underlying physics of the acceleration process. For our studies we focus on the IceCube Neutrino Observatory, a cubic kilometer neutrino detector located at the geographical South Pole. Due to its Supernova data acquisition system and its DeepCore component, dedicated to low energy neutrinos, IceCube may be sensitive to solar flare neutrinos and thus permit either a measurement of the signal or the establishment of more stringent upper limits on the solar flare neutrino flux. We present an approach for a time profile analysis based on a stacking method and an evaluation of a possible solar flare signal in IceCube using the Gean...

  11. Gravitationally-induced three-flavor neutrino oscillations as a possible solution to the solar neutrino problem

    CERN Document Server

    Mureika, J R

    1995-01-01

    Neutrinos can undergo flavor--oscillations if they possess flavor--dependent couplings to the surrounding gravitational field (the VEP mechanism). The neutrino fields can be massless, in accord with the Minimal Standard Model, but at the expense of the Einstein Equivalence Principle. We show that it is possible to explain the observed Solar Neutrino data from the various experiments using the VEP solution in a realistic three--generation framework, and further note how the three--flavor model can offer larger allowed regions of parameter space over the two--flavor models.

  12. Status of the MSW Solutions of the Solar Neutrino Problem

    CERN Document Server

    González-Garciá, M Concepción; Peña-Garay, C; Valle, José W F

    2000-01-01

    We present an updated global analysis of two-flavor MSW solutions to the solar neutrino problem in terms of conversions of nu_e into active or sterile neutrinos. We perform a fit to the full data set corresponding to the 708-day Super-Kamiokande data sample as well as to Chlorine, GALLEX and SAGE experiments. We use all measured total event rates as well as Super-Kamiokande data on the zenith angle dependence, energy spectrum and seasonal variation of the events. For conversions into active neutrinos we find that, although the data on the total event rates favours the Small Mixing Angle (SMA) solution, once the full data set is included both SMA and Large Mixing Angle (LMA) solutions give an equivalent fit to the data. The best-fit points for the combined analysis are Delta m^2=3.6 10^{-5} eV^2 sin^2(2theta)=0.8 with chi^2_min=36.3/30 d.o.f and Delta m^2=6.3~ 10^{-6} eV^2 and sin^2(2theta)=4.5 10^{-3} with chi^2_min=37.7/30 d.o.f. In contrast with the earlier 504-day study of Bahcall-Krastev-Smirnov our resul...

  13. The Solar Neutrino Problem after the first results from Kamland

    CERN Document Server

    Bandyopadhyay, A; Gandhi, R; Goswami, S; Roy, D P; Bandyopadhyay, Abhijit; Choubey, Sandhya; Gandhi, Raj; Goswami, Srubabati

    2003-01-01

    The first results from the KamLAND experiment have provided confirmational evidence for the Large Mixing Angle (LMA) MSW solution to the solar neutrino problem. We do a global analysis of solar and the recently announced KamLAND data (both rate and spectrum) and investigate its effect on the allowed region in the $\\Delta m^2-\\tan^2\\theta$ plane. The best-fit from a combined analysis which uses the KamLAND rate plus global solar data comes at $\\Delta m^2 = 6.06 \\times 10^{-5}$ eV $^2$ and $\\tan^2\\theta=0.42$, very close to the global solar best-fit, leaving a large allowed region within the global solar LMA contour. The inclusion of the KamLAND spectral data in the global fit gives a best-fit $\\Delta m^2 = 7.15 \\times 10^{-5}$ eV $^2$ and $\\tan^2\\theta=0.42$ and constrains the allowed areas within LMA, leaving essentially two allowed zones. Maximal mixing though allowed by the KamLAND data alone is disfavored by the global solar data and remains disallowed at about $3\\sigma$. The LOW solution is now ruled out ...

  14. CP-violating Phases in Active-Sterile Solar Neutrino Oscillations

    CERN Document Server

    Long, H W; Giunti, C

    2013-01-01

    Effects of CP-violating phases in active-sterile solar neutrino oscillations are discussed in a general scheme of 3+N_{s} mixing, without any constraint on the mixing between the three active and the N_{s} sterile neutrinos, assuming only a realistic hierarchy of neutrino mass-squared differences. A generalized Parke formula describing the neutrino oscillation probabilities inside the Sun is calculated. The validity of the analytical calculation and the probability variation due to the unknown CP-violating phases are illustrated with a numerical calculation of the evolution equation in the case of 3+1 neutrino mixing.

  15. Global oscillation analysis of solar neutrino data with helioseismically constrained fluxes

    CERN Document Server

    Choubey, S; Kar, K; Antia, H M; Chitre, S M; Choubey, Sandhya; Goswami, Srubabati; Kar, Kamales

    2001-01-01

    A seismic model for the Sun calculated using the accurate helioseismic data predicts a lower $^{8}{B}$ neutrino flux as compared to standard solar models (SSM). However, there persists a discrepancy between the predicted and measured fluxes and it seems necessary to invoke neutrino oscillations to explain the data. In this work, we perform a global and unified oscillation analysis of the latest solar neutrino data using the seismic model fluxes as theoretical predictions. We determine the best-fit values of the neutrino oscillation parameters and the $\\chi^2_{min}$ for both $\

  16. Neutrinos

    CERN Document Server

    de Gouvea, A; Scholberg, K; Zeller, G P; Alonso, J; Bernstein, A; Bishai, M; Elliott, S; Heeger, K; Hoffman, K; Huber, P; Kaufman, L J; Kayser, B; Link, J; Lunardini, C; Monreal, B; Morfin, J G; Robertson, H; Tayloe, R; Tolich, N; Abazajian, K; Akiri, T; Albright, C; Asaadi, J; Babu, K S; Balantekin, A B; Barbeau, P; Bass, M; Blake, A; Blondel, A; Blucher, E; Bowden, N; Brice, S J; Bross, A; Carls, B; Cavanna, F; Choudhary, B; Coloma, P; Connolly, A; Conrad, J; Convery, M; Cooper, R L; Cowen, D; da Motta, H; de Young, T; Di Lodovico, F; Diwan, M; Djurcic, Z; Dracos, M; Dodelson, S; Efremenko, Y; Ekelof, T; Feng, J L; Fleming, B; Formaggio, J; Friedland, A; Fuller, G; Gallagher, H; Geer, S; Gilchriese, M; Goodman, M; Grant, D; Gratta, G; Hall, C; Halzen, F; Harris, D; Heffner, M; Henning, R; Hewett, J L; Hill, R; Himmel, A; Horton-Smith, G; Karle, A; Katori, T; Kearns, E; Kettell, S; Klein, J; Kim, Y; Kim, Y K; Kolomensky, Yu; Kordosky, M; Kudenko, Yu; Kudryavtsev, V A; Lande, K; Lang, K; Lanza, R; Lau, K; Lee, H; Li, Z; Littlejohn, B R; Lin, C J; Liu, D; Liu, H; Long, K; Louis, W; Luk, K B; Marciano, W; Mariani, C; Marshak, M; Mauger, C; McDonald, K T; McFarland, K; McKeown, R; Messier, M; Mishra, S R; Mosel, U; Mumm, P; Nakaya, T; Nelson, J K; Nygren, D; Gann, G D Orebi; Osta, J; Palamara, O; Paley, J; Papadimitriou, V; Parke, S; Parsa, Z; Patterson, R; Piepke, A; Plunkett, R; Poon, A; Qian, X; Raaf, J; Rameika, R; Ramsey-Musolf, M; Rebel, B; Roser, R; Rosner, J; Rott, C; Rybka, G; Sahoo, H; Sangiorgio, S; Schmitz, D; Shrock, R; Shaevitz, M; Smith, N; Smy, M; Sobel, H; Sorensen, P; Sousa, A; Spitz, J; Strauss, T; Svoboda, R; Tanaka, H A; Thomas, J; Tian, X; Tschirhart, R; Tully, C; Van Bibber, K; Van de Water, R G; Vahle, P; Vogel, P; Walter, C W; Wark, D; Wascko, M; Webber, D; Weerts, H; White, C; White, H; Whitehead, L; Wilson, R J; Winslow, L; Wongjirad, T; Worcester, E; Yokoyama, M; Yoo, J; Zimmerman, E D

    2013-01-01

    This document represents the response of the Intensity Frontier Neutrino Working Group to the Snowmass charge. We summarize the current status of neutrino physics and identify many exciting future opportunities for studying the properties of neutrinos and for addressing important physics and astrophysics questions with neutrinos.

  17. Measurement of the Total Active 8B Solar Neutrino Flux at the Sudbury Neutrino Observatory with Enhanced Neutral Current Sensitivity

    CERN Document Server

    Ahmed, S N; Beier, E W; Bellerive, A; Biller, S D; Boger, J; Boulay, M G; Bowler, M G; Bowles, T J; Brice, S J; Bullard, T V; Chan, Y D; Chen, M; Chen, X; Cleveland, B T; Cox, G A; Dai, X; Dalnoki-Veress, F; Doe, P J; Dosanjh, R S; Doucas, G; Dragowsky, M R; Duba, C A; Duncan, F A; Dunford, M; Dunmore, J A; Earle, E D; Elliott, S R; Evans, H C; Ewan, G T; Farine, J; Fergani, H; Fleurot, F; Formaggio, J A; Fowler, M M; Frame, K; Fulsom, B G; Gagnon, N; Graham, K; Grant, D R; Hahn, R L; Hall, J C; Hallin, A L; Hallman, E D; Hamer, A S; Handler, W B; Hargrove, C K; Harvey, P J; Hazama, R; Heeger, K M; Heintzelman, W J; Heise, J; Helmer, R L; Hemingway, R J; Hime, A; Howe, M A; Jagam, P; Jelley, N A; Klein, J R; Kos, M S; Krumins, A V; Kutter, T; Kyba, C C M; Labranche, H; Lange, R; Law, J; Lawson, I T; Lesko, K T; Leslie, J R; Levine, I; Luoma, S; MacLellan, R; Majerus, S; Mak, H B; Maneira, J; Marino, A D; McCauley, N; McDonald, A B; McGee, S; McGregor, G; Miin, C; Miknaitis, K K S; Miller, G G; Moffat, B A; Nally, C W; Nickel, B G; Noble, A J; Norman, E B; Oblath, N S; Okada, C E; Ollerhead, R W; Orrell, J L; Oser, S M; Ouellet, C V; Peeters, S J M; Poon, A W P; Robertson, B C; Robertson, R G H; Rollin, E; Rosendahl, S S E; Rusu, V L; Schwendener, M H; Simard, O; Simpson, J J; Sims, C J; Sinclair, D; Skensved, P; Smith, M W E; Starinsky, N; Stokstad, R G; Stonehill, L C; Tafirout, R; Takeuchi, Y; Tesic, G; Thomson, M; Thorman, M; Van Berg, R; Van de Water, R G; Virtue, C J; Wall, B L; Waller, D; Waltham, C E; Wan Chan Tseung, H; Wark, D L; West, N; Wilhelmy, J B; Wilkerson, J F; Wilson, J R; Wouters, J M; Yeh, M; Zuber, K

    2004-01-01

    The Sudbury Neutrino Observatory (SNO) has precisely determined the total active (nu_x) 8B solar neutrino flux without assumptions about the energy dependence of the nu_e survival probability. The measurements were made with dissolved NaCl in the heavy water to enhance the sensitivity and signature for neutral-current interactions. The flux is found to be 5.21 +/- 0.27 (stat) +/- 0.38 (syst) x10^6 cm^{-2}s^{-1}, in agreement with previous measurements and standard solar models. A global analysis of these and other solar and reactor neutrino results yields Delta m^{2} = 7.1^{+1.2}_{-0.6}x10^{-5} ev^2 and theta = 32.5^{+2.4}_{-2.3} degrees. Maximal mixing is rejected at the equivalent of 5.4 standard deviations.

  18. Measurement of the total active 8B solar neutrino flux at the Sudbury Neutrino Observatory with enhanced neutral current sensitivity.

    Science.gov (United States)

    Ahmed, S N; Anthony, A E; Beier, E W; Bellerive, A; Biller, S D; Boger, J; Boulay, M G; Bowler, M G; Bowles, T J; Brice, S J; Bullard, T V; Chan, Y D; Chen, M; Chen, X; Cleveland, B T; Cox, G A; Dai, X; Dalnoki-Veress, F; Doe, P J; Dosanjh, R S; Doucas, G; Dragowsky, M R; Duba, C A; Duncan, F A; Dunford, M; Dunmore, J A; Earle, E D; Elliott, S R; Evans, H C; Ewan, G T; Farine, J; Fergani, H; Fleurot, F; Formaggio, J A; Fowler, M M; Frame, K; Fulsom, B G; Gagnon, N; Graham, K; Grant, D R; Hahn, R L; Hall, J C; Hallin, A L; Hallman, E D; Hamer, A S; Handler, W B; Hargrove, C K; Harvey, P J; Hazama, R; Heeger, K M; Heintzelman, W J; Heise, J; Helmer, R L; Hemingway, R J; Hime, A; Howe, M A; Jagam, P; Jelley, N A; Klein, J R; Kos, M S; Krumins, A V; Kutter, T; Kyba, C C M; Labranche, H; Lange, R; Law, J; Lawson, I T; Lesko, K T; Leslie, J R; Levine, I; Luoma, S; MacLellan, R; Majerus, S; Mak, H B; Maneira, J; Marino, A D; McCauley, N; McDonald, A B; McGee, S; McGregor, G; Mifflin, C; Miknaitis, K K S; Miller, G G; Moffat, B A; Nally, C W; Nickel, B G; Noble, A J; Norman, E B; Oblath, N S; Okada, C E; Ollerhead, R W; Orrell, J L; Oser, S M; Ouellet, C; Peeters, S J M; Poon, A W P; Robertson, B C; Robertson, R G H; Rollin, E; Rosendahl, S S E; Rusu, V L; Schwendener, M H; Simard, O; Simpson, J J; Sims, C J; Sinclair, D; Skensved, P; Smith, M W E; Starinsky, N; Stokstad, R G; Stonehill, L C; Tafirout, R; Takeuchi, Y; Tesić, G; Thomson, M; Thorman, M; Van Berg, R; Van de Water, R G; Virtue, C J; Wall, B L; Waller, D; Waltham, C E; Tseung, H Wan Chan; Wark, D L; West, N; Wilhelmy, J B; Wilkerson, J F; Wilson, J R; Wouters, J M; Yeh, M; Zuber, K

    2004-05-07

    The Sudbury Neutrino Observatory has precisely determined the total active (nu(x)) 8B solar neutrino flux without assumptions about the energy dependence of the nu(e) survival probability. The measurements were made with dissolved NaCl in heavy water to enhance the sensitivity and signature for neutral-current interactions. The flux is found to be 5.21 +/- 0.27(stat)+/-0.38(syst) x 10(6) cm(-2) s(-1), in agreement with previous measurements and standard solar models. A global analysis of these and other solar and reactor neutrino results yields Deltam(2)=7.1(+1.2)(-0.6) x 10(-5) eV(2) and theta=32.5(+2.4)(-2.3) degrees. Maximal mixing is rejected at the equivalent of 5.4 standard deviations.

  19. ecCNO solar neutrinos: A challenge for gigantic ultra-pure liquid scintillator detectors

    Science.gov (United States)

    Villante, F. L.

    2015-03-01

    Neutrinos produced in the Sun by electron capture reactions on 13N, 15O and 17F, to which we refer as ecCNO neutrinos, are not usually considered in solar neutrino analysis since the expected fluxes are extremely low. The experimental determination of this sub-dominant component of the solar neutrino flux is very difficult but could be rewarding since it provides a determination of the metallic content of the solar core and, moreover, probes the solar neutrino survival probability in the transition region at Eν ∼ 2.5 MeV. In this Letter, we suggest that this difficult measure could be at reach for future gigantic ultra-pure liquid scintillator detectors, such as LENA.

  20. ecCNO solar neutrinos: A challenge for gigantic ultra-pure liquid scintillator detectors

    Directory of Open Access Journals (Sweden)

    F.L. Villante

    2015-03-01

    Full Text Available Neutrinos produced in the Sun by electron capture reactions on 13N, 15O and 17F, to which we refer as ecCNO neutrinos, are not usually considered in solar neutrino analysis since the expected fluxes are extremely low. The experimental determination of this sub-dominant component of the solar neutrino flux is very difficult but could be rewarding since it provides a determination of the metallic content of the solar core and, moreover, probes the solar neutrino survival probability in the transition region at Eν∼2.5 MeV. In this Letter, we suggest that this difficult measure could be at reach for future gigantic ultra-pure liquid scintillator detectors, such as LENA.

  1. High Precision Measurements of $\\theta_{\\odot}$ in Solar and Reactor Neutrino Experiments

    CERN Document Server

    Bandyopadhyay, A; Goswami, S; Petcov, S T; Bandyopadhyay, Abhijit; Choubey, Sandhya; Goswami, Srubabati

    2004-01-01

    We discuss the possibilities of high precision measurement of the solar neutrino mixing angle $\\theta_\\odot \\equiv \\theta_{12}$ in solar and reactor neutrino experiments. The improvements in the determination of $\\sin^2\\theta_{12}$, which can be achieved with the expected increase of statistics and reduction of systematic errors in the currently operating solar and KamLAND experiments, are summarised. The potential of LowNu $\

  2. A Search for Periodicities in the $^8$B Solar Neutrino Flux Measured by the Sudbury Neutrino Observatory

    CERN Document Server

    Aharmim, B; Anthony, A E; Beier, E W; Bellerive, A; Bergevin, M; Biller, S D; Boulay, M G; Bowler, M G; Chan, Y D; Chen, M; Chen, X; Cleveland, B T; Costin, T; Cox, G A; Currat, C A; Dai, X; Deng, H; Detwiler, J; Doe, P J; Dosanjh, R S; Doucas, G; Duba, C A; Duncan, F A; Dunford, M; Dunmore, J A; Earle, E D; Elliott, S R; Evans, H C; Ewan, G T; Farine, J; Fergani, H; Fleurot, F; Formaggio, J A; Frati, W; Fulsom, B G; Gagnon, N; Goon, J T M; Graham, K; Hahn, R L; Hallin, A L; Hallman, E D; Handler, W B; Hargrove, C K; Harvey, P J; Hazama, R; Heeger, K M; Heelan, L; Heintzelman, W J; Heise, J; Helmer, R L; Hemingway, R J; Hime, A; Howe, M A; Huang, M; Inrig, E; Jagam, P; Jelley, N A; Klein, J R; Kormos, L L; Kos, M S; Krüger, A; Kraus, C V; Krauss, C B; Krumins, A V; Kutter, T; Kyba, C C M; Labranche, H; Lange, R; Law, J; Lawson, I T; Lesko, K T; Leslie, J R; Levine, I; Loach, J C; Luoma, S; MacLellan, R; Majerus, S; Maneira, J; Marino, A D; McCauley, N; McDonald, A B; McGee, S; Miin, C; Miknaitis, K K S; Nickel, B G; Noble, A J; Norman, E B; Oblath, N S; Okada, C E; O'Keeffe, H M; Ollerhead, R W; Orebi-Gann, G D; Orrell, J L; Oser, S M; Ouvarova, T; Peeters, S J M; Poon, A W P; Pun, C S J; Rielage, K; Robertson, B C; Robertson, R G H; Rollin, E; Rosendahl, S S E; Schwendener, M H; Seibert, S R; Simard, O; Simpson, J J; Sims, C J; Sinclair, D; Sinclair, L; Skensved, P; Smith, M W E; Stokstad, R G; Stonehill, L C; Tafirout, R; Takeuchi, Y; Tesic, G; Thomson, M; Tsang, K V; Tsui, T; Van Berg, R; Virtue, C J; Wall, B L; Waller, D; Waltham, C E; Wan Chan Tseung, H; Wark, D L; Wendland, J; West, N; Wilkerson, J F; Wilson, J R; Wouters, J M; Yeh, M; Zuber, K

    2005-01-01

    A search has been made for sinusoidal periodic variations in the $^8$B solar neutrino flux using data collected by the Sudbury Neutrino Observatory over a 4-year time interval. The variation at a period of one year is consistent with modulation of the $^8$B neutrino flux by the Earth's orbital eccentricity. No significant sinusoidal periodicities are found with periods between 1 day and 10 years with either an unbinned maximum likelihood analysis or a Lomb-Scargle periodogram analysis. The data are inconsistent with the hypothesis that the results of the recent analysis by Sturrock et al., based on elastic scattering events in Super-Kamiokande, can be attributed to a 7% sinusoidal modulation of the total $^8$B neutrino flux.

  3. Measurement of the νe and total 8B solar neutrino fluxes with the Sudbury Neutrino Observatory phase-III data set

    Science.gov (United States)

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

    2013-01-01

    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 3He 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 8B 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.)×106 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 Δm2=7.59-0.21+0.19×10-5eV2 and θ=34.4-1.2+1.3degrees.

  4. Solar neutrinos as background in dark matter searches involving electron detection

    CERN Document Server

    Vergados, J D

    2016-01-01

    In the present work we estimate the potential background of solar neutrinos on electron detectors. These detectors are considered relevant for detecting light dark matter particles in the MeV region, currently sought by experiments. We find that the copious low energy pp neutrinos are a dangerous background at the energies involved in these experiments, in fact close to the anticipated event rate, while the more energetic Boron neutrinos are harmless

  5. On the massless "just-so" solution to the solar neutrino problem

    CERN Document Server

    Guzzo, M M; De Holanda, P C; Peres, O L G

    2001-01-01

    We study the effect of the non-resonant, vacuum oscillation-like neutrino flavor conversion induced by non-standard flavor changing and non-universal flavor diagonal neutrino interactions with electrons in the sun. We have found an acceptable fit for the combined analysis for the solar experiments total rates, the Super-Kamiokande (SK) energy spectrum and zenith angle dependence. Phenomenological constraints on non-standard flavor changing and non-universal flavor diagonal neutrino interactions are considered.

  6. Solar neutrinos as background in dark matter searches involving electron detection

    Science.gov (United States)

    Thomas, A. W.; Vergados, J. D.

    2016-07-01

    In the present work we estimate the potential background of solar neutrinos on electron detectors. These detectors are considered relevant for detecting light dark matter particles in the MeV region, currently sought by experiments. We find that the copious low energy pp neutrinos are a dangerous background at the energies involved in these experiments, in fact close to the anticipated event rate, while the more energetic Boron neutrinos are harmless.

  7. Time Variations of the Superkamiokande Solar Neutrino Flux Data

    CERN Document Server

    Mandal, A S; Raychaudhuri, P; Ghosh, Koushik; Mandal, Abu Salem; Raychaudhuri, Probhas

    2006-01-01

    We have used the Date-Compensated Discrete Fourier Transform and Periodogram analysis of the solar neutrino flux data from 1) 5-day-long samples from Super-Kamiokande-I detector during the period from June, 1996 to July, 2001; 2) 10-day-long samples from the same detector during the same period and 3) 45-day-long samples from the same detector during the same period. (1) exhibits periodicity around 0.21-0.22, 0.67-0.77, 1.15-1.98, 6.72-6.95, 12.05-13.24, 22.48-24.02, 33.50 and 40.73 months. (2) shows periodicity around 0.39-0.45, 1.31-2.23, 5.20-5.32, 9.43-11.65, 13.54-14.38, 24.54, 32.99 and 41.69 months. For (3) we observe periodicity around 1.61, 14.01, 24.06, 32.50 and 42.03 months. We have found almost similar periods in the solar flares, sunspot data, solar proton data (\\bar{\\epsilon}>10 Mev) which indicates that the solar activity cycle may be due to the variable character of nuclear energy generation inside the sun.

  8. Determination of Solar Neutrino Oscillation Parameters using 1496 Days of Super-Kamiokande-I Data

    CERN Document Server

    Fukuda, S; Ishitsuka, M; Itow, Y; Kajita, T; Kameda, J; Kaneyuki, K; Kobayashi, K; Koshio, Y; Miura, M; Moriyama, S; Nakahata, M; Nakayama, S; Namba, T; Okada, A; Sakurai, N; Shiozawa, M; Suzuki, Y; Takeuchi, H; Takeuchi, Y; Totsuka, Y; Yamada, S; Desai, S; Earl, M; Kearns, E; Messier, M D; Stone, J L; Sulak, L R; Walter, C W; Goldhaber, M; Barszczak, T; Casper, D; Gajewski, W; Kropp, W R; Mine, S; Liu, D W; Smy, M B; Sobel, H W; Vagins, M R; Gago, A; Ganezer, K S; Keig, W E; Ellsworth, R W; Tasaka, S; Kibayashi, A; Learned, J G; Matsuno, S; Takemori, D; Hayato, Y; Ishii, T; Kobayashi, T; Maruyama, T; Nakamura, K; Obayashi, Y; Oyama, Y; Sakuda, M; Yoshida, M; Kohama, M; Iwashita, T; Suzuki, A T; Ichikawa, A; Inagaki, T; Kato, I; Nakaya, T; Nishikawa, K; Haines, T J; Dazeley, S; Hatakeyama, S; Svoboda, R; Blaufuss, E; Chen, M L; Goodman, J A; Guillian, G; Sullivan, G W; Turcan, D; Scholberg, K; Habig, A; Ackermann, M; Hill, J; Jung, C K; Malek, M; Martens, K; Mauger, C; McGrew, C; Sharkey, E; Viren, B; Yanagisawa, C; Toshito, T; Mitsuda, C; Miyano, K; Saji, C; Shibata, T; Kajiyama, Y; Nagashima, Y; Nitta, K; Takita, M; Kim, H I; Kim, S B; Yoo, J; Okazawa, H; Ishizuka, T; Etoh, M; Gando, Y; Hasegawa, T; Inoue, K; Ishihara, K; Shirai, J; Suzuki, A; Koshiba, M; Hatakeyama, Y; Ichikawa, Y; Koike, M; Nishijima, K; Ishino, H; Morii, M; Nishimura, R; Watanabe, Y; Kielczewska, D; Berns, H G; Boyd, S C; Stachyra, A L; Wilkes, R J

    2002-01-01

    A number of different fits to solar neutrino mixing and mass square difference were performed using 1496 days of Super-Kamiokande-I's solar neutrino data. These data select two allowed areas at large neutrino mixing when combined with either the solar $^8$B flux prediction of the standard solar model or the SNO interaction rate measurements. A global fit combining SK data with the solar neutrino interaction rates measured by Homestake, SNO, Gallex/GNO and SAGE prefers a single allowed area, the Large Mixing Angle solution, at the 98.9% confidence level. The mass square difference $\\Delta m^2$ between the two mass eigenstates ranges from about 3 to $19\\times10^{-5}$eV$^2$, while the mixing angle $\\theta$ is in the range of $\\tan^2\\theta\\approx$0.25--0.65.

  9. Solar neutrino detection in a large volume double-phase liquid argon experiment

    CERN Document Server

    Franco, D; Agnes, P; Agostino, L; Bottino, B; Davini, S; De Cecco, S; Fan, A; Fiorillo, G; Galbiati, C; Goretti, A M; Hungerford, E V; Ianni, Al; Ianni, An; Jollet, C; Marini, L; Martoff, C J; Meregaglia, A; Pagani, L; Pallavicini, M; Pantic, E; Pocar, A; Renshaw, A L; Rossi, B; Rossi, N; Suvorov, Y; Testera, G; Tonazzo, A; Wang, H; Zavatarelli, S

    2015-01-01

    The direct search for dark matter WIMP particles through their interaction with nuclei at the "neutrino floor" sensitivity, where neutrino-induced coherent scattering on nuclei starts contributing to the background, requires detectors capable of collecting exposures of the order of 1~ktonne yr free of background resulting from beta and gamma decays and cosmogenic and radiogenic neutrons. The same constraints are required for precision measurements of solar neutrinos elastically scattering on electrons. Two-phase liquid argon time projection chambers (LAr TPCs) are prime candidates for the ambitious program to explore the nature of dark matter. The large target, high scintillation light yield and good spatial resolution in all three cartesian directions concurrently allows a high precision measurement of solar neutrino fluxes. We studied the cosmogenic and radiogenic backgrounds affecting solar neutrino detection in a 300 tonne (100 tonne fiducial) LAr TPC operating at LNGS depth (3,800 meters of water equival...

  10. Combined Effect of NSI and SFP on Solar Electron Neutrino Oscillation

    Directory of Open Access Journals (Sweden)

    Deniz Yilmaz

    2016-01-01

    Full Text Available The combined effect of spin-flavor precession (SFP and the nonstandard neutrino interaction (NSI on the survival probability of solar electron neutrinos (assumed to be Dirac particles is examined for various values of ϵ11, ϵ12, and μB. It is found that the neutrino survival probability curves affected by SFP and NSI effects individually for some values of the parameters (ϵ11, ϵ12, and μB get close to the standard MSW curve when both effects are combined. Therefore, the combined effect of SFP and NSI needs to be taken into account when the solar electron neutrino data obtained by low energy solar neutrino experiments is investigated.

  11. Projections for Measuring the Size of the Solar Core with Neutrino-Electron Scattering

    Science.gov (United States)

    Davis, Jonathan H.

    2016-11-01

    We quantify the amount of data needed in order to measure the size and position of the 8B neutrino production region within the solar core, for experiments looking at elastic scattering between electrons and solar neutrinos. The directions of the electrons immediately after scattering are strongly correlated with the incident directions of the neutrinos; however, this is degraded significantly by the subsequent scattering of these electrons in the detector medium. We generate distributions of such electrons for different neutrino production profiles, and use a maximum likelihood analysis to make projections for future experimental sensitivity. We find that with approximately 20 years worth of data the Super Kamiokande experiment could constrain the central radius of the shell in which 8B neutrinos are produced to be less than 0.22 of the total solar radius at 95% confidence.

  12. pp-Solar Neutrino Spectroscopy Return of the Indium Detector

    CERN Document Server

    Raghavan, R S

    2001-01-01

    A new indium-loaded liquid scintillator (LS) with up to 15wt% In and high light output promises a breakthrough in the 25y old proposal for observing pp solar neutrinos (nue) by tagged nue capture in 115In. Intense background from the natural beta-decay of In, the single obstacle blocking this project till now, can be reduced by more than x100 with the new In-LS. Only non-In background remains, dramatically relaxing design criteria. Eight tons of In yields ~400 pp nue/y after analysis cuts. With the lowest threshold yet, Q=118 keV, In is the most sensitive detector of the pp nue spectrum, the long sought touchstone for nue conversion.

  13. New underground neutrino observatory-GENIUS-in the new millenium for solar neutrinos, dark matter and double beta decay

    CERN Document Server

    Klapdor-Kleingrothaus, H V

    2001-01-01

    Double beta decay is indispensable to solve the question of the neutrino mass matrix together with nu oscillation experiments. The most sensitive experiment for eight years-the HEIDELBERG-MOSCOW experiment in Gran-Sasso-already now, with the experimental limit of (m/sub nu /)<0.26 eV excludes degenerate nu mass scenarios allowing neutrinos as hot dark matter in the Universe for the small angle MSW solution of the solar neutrino problem. It probes cosmological models including hot dark matter already now on the level of future satellite experiments MAP and PLANCK. It further probes many topics of beyond standard model physics at the TeV scale. Future experiments should give access to the multiTeV range and complement on many ways the search for new physics at future colliders like LHC and NLC. For neutrino physics GENIUS will allow to test almost all neutrino mass scenarios allowed by the present neutrino oscillation experiments. At the same time GENIUS will cover a wide range of the parameter space of pred...

  14. New neutrino source for the study of solar neutrino physics in the vacuum-matter transition region

    Science.gov (United States)

    Shin, Jae Won; Cheoun, Myung-Ki; Park, Tae-Sun; Kajino, Toshitaka

    2016-10-01

    Production of a neutrino source through a proton-induced reaction is studied by using the particle transport code geant4. Unstable isotopes such as 27Si can be produced when the 27Al target is bombarded by 15-MeV energetic proton beams. Through the β -decay process of the unstable isotope, a new electron-neutrino source in the 0-5.0 MeV energy range is obtained. Proton-induced reactions are simulated with JENDL-4.0 High Energy File (JENDL-4.0/HE). For radioactive decay processes, we use the G4 radioactive decay model based on the Evaluated Nuclear Structure Data File (ENSDF). We suggest detailed target systems required for future solar neutrino experiments, in particular for the vacuum-matter transition region. As for a detection system of the new neutrino source, we evaluate reaction or event rates for available radiochemical detectors and Low Energy Neutrino Astronomy (LENA)-type scintillator detector and discuss effects due to possible sterile neutrinos as an application.

  15. Dissertation Award in Nuclear Physics Prize Talk: Model-Independent Measurement of the ^8B Solar Neutrino Flux and Evidence for Neutrino Flavor Change at SNO

    Science.gov (United States)

    Heeger, Karsten M.

    2003-04-01

    With heavy water as a target medium the Sudbury Neutrino Observatory (SNO) is designed to study solar neutrinos by measuring both the total flux of ^8B neutrinos through the neutral-current interaction as well as the electron-type neutrino flux via charged-current dissociation of deuterium. Using data from the pure D_2O phase of SNO we have determined the interaction rates of solar neutrinos with deuterium and characterized the backgrounds throughout the SNO detector volume. Without assumptions about the shape of the underlying ^8B spectrum a model-independent measurement of the total flux of active solar ^8B neutrinos is made. The measurement of the neutral-current and charged-current interaction rates provides direct evidence for the flavor transformation of solar neutrinos and indicates that neutrinos have mass. A combined analysis of solar neutrino data from SNO and Super-Kamiokande can be used to constrain the leading weak axial two-body current, the dominant uncertainty of the low-energy weak interaction deuteron breakup process. It is shown that the theoretical inputs to SNO's determination of the CC and NC interaction rates are not a significant theoretical uncertainty and can be self-calibrated.

  16. Has a standard model solution to the solar neutrino problem been found?

    Energy Technology Data Exchange (ETDEWEB)

    Bahcall, J.N.; Barnes, C.A.; Christensen-Dalsgaard, J.; Cleveland, B.T.; Degl' Innocenti, S.; Filippone, B.W.; Glasner, A.; Kavanagh, R.W.; Koonin, S.E.; Lande, K.; Langanke, K.; Parker, P.D.; Pinsonneault, M.H.; Proffitt, C.R.; Shoppa, T.

    1994-08-01

    The claim by Dar and Shaviv that they have found a standard model solution to the solar neutrino problem is base upon an incorrect assumption made in extrapolating nuclear cross sections and the selective use of a small fraction of the nuclear physics and of the neutrino data. In addition, five different solar model codes show that the rate obtained for the chlorine experiment using the Dar- Shaviv stated parameters differs by a least 14{sigma} from the observed rate.

  17. The SNO+ Scintillator Purification Plant and Projected Sensitivity to Solar Neutrinos in the Pure Scintillator Phase

    Science.gov (United States)

    Pershing, Teal; SNO+ Collaboration

    2016-03-01

    The SNO+ detector is a neutrino and neutrinoless double-beta decay experiment utilizing the renovated SNO detector. In the second phase of operation, the SNO+ detector will contain 780 tons of organic liquid scintillator composed of 2 g/L 2,5-diphenyloxazole (PPO) in linear alkylbenzene (LAB). In this phase, SNO+ will strive to detect solar neutrinos in the sub-MeV range, including CNO production neutrinos and pp production neutrinos. To achieve the necessary detector sensitivity, a four-part scintillator purification plant has been constructed in SNOLAB for the removal of ionic and radioactive impurities. We present an overview of the SNO+ scintillator purification plant stages, including distillation, water extraction, gas stripping, and metal scavenger columns. We also give the projected SNO+ sensitivities to various solar-produced neutrinos based on the scintillator plant's projected purification efficiency.

  18. A Search for Neutrinos from the Solar hep Reaction and the Diffuse Supernova Neutrino Background with the Sudbury Neutrino Observatory

    CERN Document Server

    Ahmed, S N; Beier, E W; Bellerive, A; Bergevin, M; Biller, S D; Boulay, M G; Chan, Y D; Chen, M; Chen, X; Cleveland, B T; Cox, G A; Currat, C A; Dai, X; Dalnoki-Veress, F; Deng, H; Detwiler, J; Di Marco, M; Doe, P J; Doucas, G; Drouin, P L; Duncan, F A; Dunford, M; Dunmore, J A; Earle, E D; Evans, H C; Ewan, G T; Farine, J; Fergani, H; Fleurot, F; Ford, R J; Formaggio, J A; Gagnon, N; Goon, J TM; Graham, K; Guillian, E; Hahn, R L; Hallin, A L; Hallman, E D; Harvey, P J; Hazama, R; Heeger, K M; Heintzelman, W J; Heise, J; Helmer, R L; Hemingway, R J; Henning, R; Hime, A; Howard, C; Howe, M A; Huang, M; Jagam, P; Jelley, N A; Klein, J R; Kormos, L L; Kos, M; Krüger, A; Kraus, C V; Krauss, C B; Kutter, T; Kyba, C C M; Labranche, H; Lange, R; Law, J; Lawson, I T; Lesko, K T; Leslie, J R; Loach, J C; Luoma, S; MacLellan, R; Majerus, S; Mak, H B; Maneira, J; Marino, A D; Martin, R; McCauley, N; McDonald, A B; McGee, S; Miin, C; Miknaitis, K K S; Miller, M L; Monreal, B; Nickel, B G; Noble, A J; Norman, E B; Oblath, N S; Okada, C E; O'Keeffe, H M; Orebi-Gann, G D; Oser, S M; Ott, R; Peeters, S J M; Poon, A W P; Prior, G; Rielage, K; Robertson, B C; Robertson, R G H; Rollin, E; Schwendener, M H; Secrest, J A; Seibert, S R; Simard, O; Sims, C J; Sinclair, D; Skensved, P; Stokstad, R G; Stonehill, L C; Tesic, G; Tolich, N; Tsui, T; Van Berg, R; Van de Water, R G; Van Devender, B A; Virtue, C J; Walker, T J; Wall, B L; Waller, D; Wan Chan Tseung, H; Wark, D L; Wendland, J; West, N; Wilkerson, J F; Wilson, J R; Wouters, J M; Wright, A; Yeh, M; Zhang, F; Zuber, K

    2006-01-01

    A search has been made for neutrinos from the hep reaction in the Sun and from the diffuse supernova neutrino background (DSNB) using data collected during the first operational phase of the Sudbury Neutrino Observatory. For the hep neutrino search, two events are observed in the effective electron energy range of 14.3 MeV neutrino oscillations, an upper limit of 2.3x10^4 cm^{-2}s^{-1} at the 90% confidence level is inferred on the total flux of hep neutrinos. For DSNB neutrinos, no events are observed in the effective electron energy range of 21 MeV neutrino energy range of 22.9 MeV neutrino flux and by two orders of magnitude on the previous upper limit on the...

  19. Neutrino Physics

    Science.gov (United States)

    Bergström, L.; Hulth, P. O.; Botner, O.; Carlson, P.; Ohlsson, T.

    2006-03-01

    J. N. Bahcall (1934-2005) -- Preface -- List of participants -- Committees -- Nobel symposium on neutrino physics - program -- The history of neutrino oscillations / S. M. Bilenky -- Super-Kamiokande results on neutrino oscillations / Y. Suzuki -- Sudbury neutrino observatory results / A. B. McDonald -- Results from KamLAND reactor neutrino detection / A. Suzuki -- New opportunities for surprise / J. Conrad -- Solar models and solar neutrinos / J. N. Bahcall -- Atmospheric neutrino fluxes / T. K. Gaisser -- The MSW effect and matter effects in neutrino oscillations / A. Yu. Smirnov -- Three-flavour effects and CP- and T-violation in neutrino oscillations / E. Kh. Akhmedov -- Global analysis of neutrino data / M. C. Gonzalez-Garcia -- Future precision neutrino oscillation experiments and theoretical implications / M. Lindner -- Experimental prospects of neutrinoless double beta decay / E. Fiorini -- Theoretical prospects of neutrinoless double beta decay / S. T. Petcov -- Supernova neutrino oscillations / G. G. Raffelt -- High-energy neutrino astronomy / F. Halzen -- Neutrino astrophysics in the cold: Amanda, Baikal and IceCube / C. Spiering -- Status of radio and acoustic detection of ultra-high energy cosmic neutrinos and a proposal on reporting results / D. Saltzberg -- Detection of neutrino-induced air showers / A. A. Watson -- Prospect for relic neutrino searches / G. B. Gelmini -- Leptogenesis in the early universe / T. Yanagida -- Neutrinos and big bang nucleosynthesis / G. Steigman -- Extra galactic sources of high energy neutrinos / E. Waxman -- Cosmological neutrino bounds for non-cosmologists / M. Tegmark -- Neutrino intrinsic properties: the neutrino-antineutrino relation / B. Kayser -- NuTeV and neutrino properties / M. H. Shaevitz -- Absolute masses of neutrinos - experimental results and future possibilities / C. Weinheimer -- Flavor theories and neutrino masses / P. Ramond -- Neutrino mass models and leptogenesis / S. F. King -- Neutrino mass and

  20. Projections for measuring the size of the solar core with neutrino-electron scattering

    CERN Document Server

    Davis, Jonathan H

    2016-01-01

    We quantify the amount of data needed in order to measure the size of the solar core with future experiments looking at elastic scattering between electrons and solar neutrinos. The directions of the electrons immediately after scattering are strongly correlated with the incident directions of the neutrinos, however this is degraded significantly by the subsequent scattering of these electrons in the detector medium. We generate distributions of such electrons for different sizes of the solar core, and use a maximum likelihood analysis to make projections for future experimental sensitivity. We find that after approximately 5 years of data-taking an experiment the size of Hyper Kamiokande could measure the solar core radius with an uncertainty of 20% of the total solar radius at 95% confidence, and could exclude the scenario where the neutrinos are produced throughout the entire sun at 3 $\\sigma$.

  1. Solar neutrinos: probing the quasi-isothermal solar core produced by supersymmetric dark matter particles.

    Science.gov (United States)

    Lopes, Ilídio P; Silk, Joseph

    2002-04-15

    SNO measurements strongly constrain the central temperature of the Sun, to within a precision of much less than 1%. This result can be used to probe the parameter space of supersymmetric dark matter. In this first analysis we find a lower limit for the weakly interacting massive particle (WIMP) mass of 60 GeV. Furthermore, in the event that WIMPs create a quasi-isothermal core, they will produce a peculiar distribution of the solar neutrino fluxes measured on Earth. Typically, a WIMP with a mass of 100 GeV and annihilation cross section of 10(-34) cm(3)/sec will decrease the neutrino predictions, by up to 4% for the Cl, by 3% for the heavy water, and by 1% for the Ga detectors.

  2. A new neutrino source for the study of the solar neutrino physics in the vacuum-matter transition region

    CERN Document Server

    Shin, Jae Won

    2016-01-01

    Production of a neutrino source through proton induced reaction is studied by using the particle transport code, GEANT4. Unstable isotope such as $^{27}$Si can be produced when $^{27}$Al target is bombarded by 15 MeV energetic proton beams. Through the beta decay process of the unstable isotope, a new electron-neutrino source in the 1.0 $\\sim$ 5.0 MeV energy range is obtained. Proton induced reactions are simulated with JENDL High Energy File 2007 (JENDL/HE-2007) data and other nuclear data. For radioactive decay processes, we use "G4RadioactiveDecay" model based on the Evaluated Nuclear Structure Data File (ENSDF). We suggest target systems required for future's solar neutrino experiments, in particular, for the vacuum-matter transition region. As for the detection system of the new neutrino source, we evaluate reaction rates for available radiochemical detectors and LENA type scintillator detector. Possibility of detecting sterile neutrinos is also discussed.

  3. Reconciling cold dark matter with COBE/IRAS plus solar and atmospheric neutrino data

    Energy Technology Data Exchange (ETDEWEB)

    Joshipura, A.S. [Valencia Univ. (Spain). Dept. de Fisica Teorica; Valle, J.W.F. [Valencia Univ. (Spain). Dept. de Fisica Teorica

    1995-05-01

    We present a model where an unstable MeV Majorana tau neutrino can naturally reconcile the cold dark matter model (CDM) with cosmological observations of large and small scale density fluctuations and, simultaneously, with data on solar and atmospheric neutrinos. The solar neutrino deficit is explained through long wavelength, so-called just-so oscillations involving conversions of {nu}{sub e} into both {nu}{sub {mu}} and a sterile species {nu}{sub S} , while atmospheric neutrino data are explained through {nu}{sub {mu}} to {nu}{sub e} conversions. Future long baseline neutrino oscillation experiments, as well as some reactor experiments will test this hypothesis. The model is based on the spontaneous violation of a global lepton number symmetry at the weak scale. This symmetry plays a key role in generating the cosmologically required decay of the {nu}{sub {tau}} with lifetime {tau}{sub {nu}{sub {tau}}} similar 10{sup 2}-10{sup 4} seconds, as well as the masses and oscillations of the three light neutrinos {nu}{sub e} , {nu}{sub {mu}} and {nu}{sub S} required in order to account for solar and atmospheric neutrino data. It also leads to the invisibly decaying Higgs signature that can be searched at LEP and future particle colliders. ((orig.)).

  4. Gallex 1 measures hydrogen fusion neutrinos. A look into the solar furnace. Gallex 1 misst Wasserstoff-Fusions-Neutrinos. Blick in den Ofen der Sonne

    Energy Technology Data Exchange (ETDEWEB)

    Hintsches, E. (Max-Planck-Gesellschaft, Muenchen (Germany). Pressereferat)

    1992-09-25

    One of the central mysteries of science is about to be solved. The 'solar furnace' appears to function along the principles established by theoretical studies. The European gallium experiment 'Gallex' is the first to measure the main function of hydrogen fusion neutrinos. There is nothing to suggest neutrino mass. (orig.).

  5. Analytical treatment of long-term observations of the day-night asymmetry for solar neutrinos

    CERN Document Server

    Aleshin, S S; Lobanov, A E; 10.1103/PhysRevD.87.045025

    2013-01-01

    The Earth's density distribution can be approximately considered piecewise continuous at the scale of two-flavor oscillations of typical solar neutrinos, such as the beryllium-7 and boron-8 neutrinos. This quite general assumption appears to be enough to analytically calculate the day-night asymmetry factor for such neutrinos. Using the explicit time averaging procedure, we show that, within the leading-order approximation, this factor is determined by the electron density within about one oscillation length under the detector, namely, in the Earth's crust (and upper mantle for high-energy neutrinos). We also evaluate the effect of the inner Earth's structure on the observed asymmetry and show that it is suppressed and mainly comes from the neutrinos observed near the winter and summer solstices. As a result, we arrive at the strict interval constraint on the asymmetry, which is valid within quite a wide class of Earth models.

  6. Random magnetic fields inducing solar neutrino spin-flavor precession in a three generation context

    CERN Document Server

    Guzzo, M M; Peres, O L G

    2005-01-01

    We study the effect of random magnetic fields in the spin-flavor precession of solar neutrinos in a three generation context, when a non-vanishing transition magnetic moment is assumed. While this kind of precession is strongly constrained when the magnetic moment involves the first family, such constraints do not apply if we suppose a transition magnetic moment between the second and third families. In this scenario we can have a large non-electron anti-neutrino flux arriving on Earth, which can lead to some interesting phenomenological consequences, as, for instance, the suppression of day-night asymmetry. We have analyzed the high energy solar neutrino data and the KamLAND experiment to constrain the solar mixing angle, and solar mass difference, and we have found a larger shift of allowed values.

  7. Measurement of the 8B Solar Neutrino Flux with KamLAND

    Energy Technology Data Exchange (ETDEWEB)

    Abe, S.; Furuno, K.; Gando, A.; Gando, Y.; Ichimura, K.; Ikeda, H.; Inoue, K.; Kibe, Y.; Kimura, W.; Kishimoto, Y.; Koga, M.; Minekawa, Y.; Mitsui, T.; Morikawa, T.; Nagai, N.; Nakajima, K.; Nakamura, K.; Nakamura, M.; Narita, K.; Shimizu, I.; Shimizu, Y.; Shirai, J.; Suekane, F.; Suzuki, A.; Takahashi, H.; Takahashi, N.; Takemoto, Y.; Tamae, K.; Watanabe, H.; Xu, B.D.; Yabumoto, H.; Yonezawa, E.; Yoshida, H.; Yoshida, S.; Enomoto, S.; Kozlov, A.; Murayama, H.; Grant, C.; Keefer, G.; McKee, D.; Piepke, A.; Banks, T.I.; Bloxham, T.; Detwiler, J.A.; Freedman, S.J.; Fujikawa, B.K.; Han, K.; Kadel, R.; O' Donnell, T.; Steiner, H.M.; Winslow, L.A.; Dwyer, D.A.; Mauger, C.; McKeown, R.D.; Zhang, C.; Berger, B.E.; Lane, C.E.; Maricic, J.; Miletic, T.; Batygov, M.; Learned, J.G.; Matsuno, S.; Pakvasa, S.; Sakai, M.; Horton-Smith, G.A.; Tang, A.; Downum, K.E.; Gratta, G.; Tolich, K.; Efremenko, Y.; Kamyshkov, Y.; Perevozchikov, O.; Karwowski, H.J.; Markoff, D.M.; Tornow, W.; Heeger, K.M.; Piquemal, F.; Ricol, J.-S.; Decowski, M.P.

    2011-06-04

    We report a measurement of the neutrino-electron elastic scattering rate from {sup 8}B solar neutrinos based on a 123 kton-day exposure of KamLAND. The background-subtracted electron recoil rate, above a 5.5-MeV analysis threshold is 1.49 {+-} 0.14(stat) {+-} 0.17(syst) events per kton-day. Interpreted as due to a pure electron flavor flux with a {sup 8}B neutrino spectrum, this corresponds to a spectrum integrated flux of 2.77 {+-} 0.26(stat) {+-} 0.32(syst) x 10{sup 6} cm{sup -2}s{sup -1}. The analysis threshold is driven by {sup 208}Tl present in the liquid scintillator, and the main source of systematic uncertainty is due to background from cosmogenic {sup 11}Be. The measured rate is consistent with existing measurements and with standard solar model predictions which include matter-enhanced neutrino oscillation.

  8. Measurement of the 8B Solar Neutrino Flux with KamLAND

    CERN Document Server

    Abe, S; Gando, A; Gando, Y; Ichimura, K; Ikeda, H; Inoue, K; Kibe, Y; Kimura, W; Kishimoto, Y; Koga, M; Minekawa, Y; Mitsui, T; Morikawa, T; Nagai, N; Nakajima, K; Nakamura, K; Nakamura, M; Narita, K; Shimizu, I; Shimizu, Y; Shirai, J; Suekane, F; Suzuki, A; Takahashi, H; Takahashi, N; Takemoto, Y; Tamae, K; Watanabe, H; Xu, B D; Yabumoto, H; Yonezawa, E; Yoshida, H; Yoshida, S; Enomoto, S; Kozlov, A; Murayama, H; Grant, C; Keefer, G; McKee, D; Piepke, A; Banks, T I; Bloxham, T; Detwiler, J A; Freedman, S J; Fujikawa, B K; Han, K; Kadel, R; O'Donnell, T; Steiner, H M; Winslow, L A; Dwyer, D A; Mauger, C; McKeown, R D; Zhang, C; Berger, B E; Lane, C E; Maricic, J; Miletic, T; Batygov, M; Learned, J G; Matsuno, S; Pakvasa, S; Sakai, M; Horton-Smith, G A; Tang, A; Downum, K E; Gratta, G; Tolich, K; Efremenko, Y; Kamyshkov, Y; Perevozchikov, O; Karwowski, H J; Markoff, D M; Tornow, W; Heeger, K M; Piquemal, F; Ricol, J -S; Decowski, M P

    2011-01-01

    We report a measurement of the neutrino-electron elastic scattering rate from 8B solar neutrinos based on a 123 kton-day exposure of KamLAND. The background-subtracted electron recoil rate, above a 5.5 MeV analysis threshold is 1.49+/-0.14(stat)+/-0.17(syst) events per kton-day. Interpreted as due to a pure electron flavor flux with a 8B neutrino spectrum, this corresponds to a spectrum integrated flux of 2.77+/-0.26(stat)+/-0.32(syst) x 10^6 cm^-2s^-1. The analysis threshold is driven by 208Tl present in the liquid scintillator, and the main source of systematic uncertainty is due to background from cosmogenic 11Be. The measured rate is consistent with existing measurements and with Standard Solar Model predictions which include matter enhanced neutrino oscillation.

  9. Possible radiative decays of solar neutrinos. Expectations from the total solar eclipse - 11th August 1999

    CERN Document Server

    Tanasa, A

    2001-01-01

    The paper treats the possibility of radiative decays of the oscillation product of the electron neutrinos coming from the Sun; to eliminate the background of photons collected with the telescope, the totality phase of the Total Solar Eclipse from August, 1999 in Romania will be used. To minimize this background in the NOTTE experiment (Neutrino Oscillation with Telescope during the Total Eclipse) one telescope will be mounted aboard a MIG29 plain flying in the totality band at high altitude. A theoretical calculation of the distribution of the distance from the center of the telescope for the decay photons is presented. Similar experiments could be placed aboard satellites having the advantage that the Earth occults the Sun every day while the detection time would be much longer than a typical eclipse duration. A positive result of such an experiment would be relevant not only for neutrino physics but also for astroparticle physics, dark matter searches and cosmology. Even negative results would lead to impro...

  10. Improving LMA predictions with non-standard interactions: neutrino decay in solar matter?

    CERN Document Server

    Das, C R

    2010-01-01

    It has been known for some time that the well established LMA solution to the observed solar neutrino deficit fails to predict a flat energy spectrum for SuperKamiokande as opposed to what the data indicates. It also leads to a Chlorine rate which appears to be too high as compared to the data. We investigate the possible solution to these inconsistencies with non standard neutrino interactions, assuming that they come as extra contributions to the $\

  11. A possible mechanism to cause the quasi-biennial variability on the solar neutrino flux

    Science.gov (United States)

    Sakurai, K.; Hasegawa, M.

    1985-01-01

    It is suggested that the quasi-biennial change in the observed flux of the solar neutrinos is causally related to some non-linear process at the central core of the Sun, being associated with the charge in the central temperature. This process seems to be responsible for the physical adjustment of the internal structure of the Sun. Numerical simulation on this process is able to reproduce the quasi-biennial change in the flux of these neutrinos.

  12. Measurement of the 8B solar neutrino flux with the KamLAND liquid scintillator detector

    NARCIS (Netherlands)

    Abe, S.; et al., [Unknown; Decowski, M.P.

    2011-01-01

    We report a measurement of the neutrino-electron elastic scattering rate from 8B solar neutrinos based on a 123 kton-day exposure of KamLAND. The background-subtracted electron recoil rate, above a 5.5-MeV analysis threshold is 1.49 ± 0.14(stat) ± 0.17(syst) events per kton-day. Interpreted as due t

  13. Matter Effects of Thin Layers Detecting Oil by Oscillations of Solar Neutrinos

    CERN Document Server

    Ioannisian, A N; Ioannisian, Ara N.; Smirnov, Alexei Yu.

    2002-01-01

    We consider a possibility to use the solar neutrinos for studies of small scale structures of the Earth and for geological research. Effects of thin layers of matter with density contrast on oscillations of Beryllium neutrinos inside the Earth are studied. We find that change of the $^7Be$ neutrino flux can reach 0.25 % for layers with density of oil and size $(10 - 100)$ km. Problems of detection are discussed. Hypothetical method would consist of measuring the $^7Be -$ flux by e.g. large deep underwater detector-submarine which could change its location.

  14. Spectroscopy of low energy solar neutrinos using CdTe detectors

    Science.gov (United States)

    Zuber, K.

    2003-10-01

    The usage of a large amount of CdTe(CdZnTe) semiconductor detectors for solar neutrino spectroscopy in the low energy region is investigated. Several different coincidence signals can be formed on five different isotopes to measure the 7Be neutrino line at 862 keV in real-time. The most promising one is the usage of 116Cd resulting in 227 SNU. The presence of 125Te permits even the real-time detection of pp-neutrinos. A possible antineutrino flux above 713 keV might be detected by capture on 106Cd.

  15. Comparative Analyses of Brookhaven National Laboratory Nuclear Decay Measurements and Super-Kamiokande Solar Neutrino Measurements: Neutrinos and Neutrino-Induced Beta-Decays as Probes of the Deep Solar Interior

    Science.gov (United States)

    Sturrock, P. A.; Fischbach, E.; Scargle, J. D.

    2016-12-01

    An experiment carried out at the Brookhaven National Laboratory over a period of almost 8 years acquired 364 measurements of the beta-decay rates of a sample of {}^{32}Si and, for comparison, of a sample of {}^{36}Cl. The experimenters reported finding " small periodic annual deviations of the data points from an exponential decay … of uncertain origin". We find that power-spectrum and spectrogram analyses of these datasets show evidence not only of the annual oscillations, but also of transient oscillations with frequencies near 11 year-1 and 12.5 year-1. Similar analyses of 358 measurements of the solar neutrino flux acquired by the Super-Kamiokande neutrino observatory over a period of about 5 years yield evidence of an oscillation near 12.5 year-1 and another near 9.5 year-1. An oscillation near 12.5 year-1 is compatible with the influence of rotation of the radiative zone. We suggest that an oscillation near 9.5 year-1 may be indicative of rotation of the solar core, and that an oscillation near 11 year-1 may have its origin in a tachocline between the core and the radiative zone. Modulation of the solar neutrino flux may be attributed to an influence of the Sun's internal magnetic field by the Resonant Spin Flavor Precession (RSFP) mechanism, suggesting that neutrinos and neutrino-induced beta decays can provide information about the deep solar interior.

  16. Solar neutrinos and the MSW effect for three-neutrino mixing

    Science.gov (United States)

    Shi, X.; Schramm, David N.

    1991-01-01

    Researchers considered three-neutrino Mikheyev-Smirnov-Wolfenstein (MSW) mixing, assuming m sub 3 is much greater than m sub 2 is greater than m sub 1 as expected from theoretical consideration if neutrinos have mass. They calculated the corresponding mixing parameter space allowed by the Cl-37 and Kamiokande 2 experiments. They also calculated the expected depletion for the Ga-71 experiment. They explored a range of theoretical uncertainty due to possible astrophysical effects by varying the B-8 neutrino flux and redoing the MSW mixing calculation.

  17. The instability of strong magnetic fields in stellar interiors. [solar neutrino flux limits

    Science.gov (United States)

    Parker, E. N.

    1974-01-01

    There has been discussion of the possibility of resolving the solar neutrino dilemma with a sufficiently strong magnetic field (500 MG) in the solar interior to relieve the gas pressure by some 10% or more. The time in which magnetic buoyancy will bring a strong field to the surface is examined and is found to be less than 100 m.y. No possibility is seen for retaining a suitably strong magnetic field in the solar interior.

  18. Using low-energy neutrinos from pion decay at rest to probe the proton strangeness.

    Science.gov (United States)

    Pagliaroli, G; Lujan-Peschard, C; Mitra, M; Vissani, F

    2013-07-12

    The study of the neutral current elastic scattering of neutrinos on protons at lower energies can be used as a compelling probe to improve our knowledge of the strangeness of the proton. We consider a neutrino beam generated from pion decay at rest, as provided by a cyclotron or a spallation neutron source and a 1 kton scintillating detector with a potential similar to the Borexino detector. Despite several backgrounds from solar and radioactive sources, it is possible to estimate two optimal energy windows for the analysis, one between 0.65 and 1.1 MeV and another between 1.73 and 2.2 MeV. The expected number of neutral current events in these two regions, for an exposure of 1 yr, is enough to obtain an error on the strange axial charge 10 times smaller than available at present.

  19. An Investigation of Equivalence Principle Violations Using Solar Neutrino Oscillations in a Constant Gravitational Potential

    CERN Document Server

    Mureika, J R

    1996-01-01

    Neutrino oscillations induced by a flavor-dependent violation of the Einstein Equivalence Principle (VEP) have been recently considered as a suitable explanation of the solar electron-neutrino deficiency. Unlike the MSW oscillation mechanism, the VEP mechanism is dependent on a coupling to the local background gravitational potential $\\Phi$. We investigate the differences which arise by considering three-flavor VEP neutrinos oscillating against fixed background potentials, and against the radially-dependent solar potential. This can help determine the sensitivity of the gravitationally-induced oscillations to both constancy and size (order of magnitude) of $\\Phi$. In particular, we consider the potential of the local superculster, $|\\Phi|=3\\times 10^{-5}$, in light of recent work suggesting that the varying solar potential has no effect on the oscillations. The possibility for arbitrarily large background potentials in different cosmologies is discussed, and the effects of one such potential ($\\Phi = 10^{-3}$...

  20. Detection of sub-GeV Dark Matter and Solar Neutrinos via Chemical-Bond Breaking

    CERN Document Server

    Essig, Rouven; Slone, Oren; Volansky, Tomer

    2016-01-01

    We explore a new low-threshold direct-detection concept for dark matter, based on the breaking of chemical bonds between atoms. This includes the dissociation of molecules and the creation of defects in a lattice. With thresholds of a few to 10's of eV, such an experiment could probe the nuclear couplings of dark matter particles as light as a few MeV. We calculate the expected rates for dark matter to break apart diatomic molecules, which we take as a case study for more general systems. We briefly mention ideas for how chemical-bond breaking might be detected in practice. We also discuss the possibility of detecting solar neutrinos, including pp neutrinos, with this experimental concept. With an event rate of $\\mathcal{O}$(0.1/kg-year), large exposures are required, but measuring low-energy solar neutrinos would provide a crucial test of the solar model.

  1. Rotational Signature and Possible R-Mode Signature in the GALLEX Solar Neutrino Data

    CERN Document Server

    Sturrock, P A; Wheatland, M S; Walther, G

    1999-01-01

    Recent analysis of the Homestake data indicates that the solar neutrino flux contains a periodic variation that may be attributed to rotational modulation occurring deep in the solar interior, either in the tachocline or in the radiative zone. This paper presents an analysis of GALLEX data that yields supporting evidence of this rotational modulation at the 0.1% significance level. The depth of modulation inferred from the rotational signature is large enough to explain the neutrino deficit. The Rieger 157-day periodicity, first discovered in solar gamma-ray flares, is present also in Homestake data. A related oscillation with period 52 days is found in the GALLEX data. The relationship of these periods to the rotational period inferred from neutrino data suggests that they are due to r-mode oscillations.

  2. Solar Neutrino Oscillation Parameters after SNO Phase-Ⅲ and SAGE Part-Ⅲ

    Institute of Scientific and Technical Information of China (English)

    YANG Ping; LIU Qiu-Yu

    2009-01-01

    We analyse the recently published results from solar neutrino experiments SNO Phase-Ⅲ and SAGE Part-Ⅲ and show their constraints on solar neutrino oscillation parameters,especially for the mixing angle θ12.Through a global analysis using all existing data from SK,SNO,Ga&C1 radiochemical experiments and long base line reactor experiment KamLAND,we obtain the parameters Δm212=7.684+0.212-0.208×10-5 eV2,tan2 θ12-0.440+0.059-0.057.We also find that the discrepancy between the KamLAND and solar neutrino results can be reduced by choosing a small non-zero value for the mixing angle θ13.

  3. Measurement of the solar neutrino capture rate with gallium metal, part III

    Energy Technology Data Exchange (ETDEWEB)

    Elliott, Steven Ray [Los Alamos National Laboratory

    2008-01-01

    The Russian-American experiment SAGE began to measure the solar neutrino capture rate with a target of gallium metal in December 1989. Measurements have continued with only a few brief interruptions since that time. In this article we present the experimental improvements in SAGE since its last published data summary in December 2001. Assuming the solar neutrino production rate was constant during the period of data collection, combined analysis of 168 extractions through December 2007 gives a capture rate of solar neutrinos with energy more than 233 keY of 65.4{sup +3.1}{sub 3.0} (stat) {sup +2.6}{sub -2.8} (syst) SNU. The weighted average of the results of all three Ga solar neUlrino experiments, SAGE, Gallex, and GNO, is now 66.1 {+-} 3.1 SNU, where statistical and systematic uncertainties have been combined in quadrature. During the recent period of data collection a new test of SAGE was made with a reactor-produced {sup 37}Ar neutrino source. The ratio of observed to calculated rates in this experiment, combined with the measured rates in the three prior {sup 51}Cr neutrino-source experiments with Ga, is 0.88 {+-} 0.05. A probable explanation for this low result is that the cross section for neutrino capture by the two lowest-lying excited states in {sup 71}Ge has been overestimated. If we assume these cross sections are zero, then the standard solar model including neutrino oscillations predicts a total capture rate in Ga in the range of 63--67 SNU with an uncertainly of about 5%, in good agreement with experiment. We derive the current value of the pp neutrino flux produced in the Sun to be {phi}{sup {circle_dot}}{sub pp} = (6.1 {+-} 0.8) x 10{sup 10}/(cm{sup 2} s), which agrees well with the flux predicted by the standard solar model. Finally, we make several tests and show that the data are consistent with the assumption that the solar neutrino production rate is constant in time.

  4. Measurement of the solar neutrino capture rate with gallium metal, Part III

    CERN Document Server

    Abdurashitov, J N; Gorbachev, V V; Gurkina, P P; Ibragimova, T V; Kalikhov, A V; Khairnasov, N G; Knodel, T V; Mirmov, I N; Shikhin, A A; Veretenkin, E P; Yants, V E; Zatsepin, G T; Bowles, T J; Elliott, S R; Teasdale, W A; Nico, J S; Cleveland, B T; Wilkerson, J F

    2009-01-01

    The Russian-American experiment SAGE began to measure the solar neutrino capture rate with a target of gallium metal in December 1989. Measurements have continued with only a few brief interruptions since that time. We give here the experimental improvements in SAGE since its last published data summary in December 2001. Assuming the solar neutrino production rate was constant during the period of data collection, combined analysis of 168 extractions through December 2007 gives a capture rate of solar neutrinos with energy more than 233 keV of 65.4 (+3.1)(-3.0) (stat) (+2.6)(-2.8) (syst) SNU. The weighted average of the results of all three Ga solar neutrino experiments, SAGE, Gallex, and GNO, is now 66.1 +/- 3.1 SNU, where statistical and systematic uncertainties have been combined in quadrature. During the recent period of data collection a new test of SAGE was made with a reactor-produced 37Ar neutrino source. The ratio of observed to calculated rates in this experiment, combined with the measured rates in...

  5. Geo-neutrino review

    Energy Technology Data Exchange (ETDEWEB)

    Tolich, N., E-mail: ntolich@u.washington.edu [Center for Experimental Nuclear Physics and Astrophysics, and Departments of Physics, University of Washington, Seattle, WA, 98195 (United States)

    2012-08-15

    The principal source of energy for dynamic processes of the earth, such as plate tectonics is thought to come from the radioactive decays of {sup 238}U, {sup 232}Th, and {sup 40}K within the earth. These decays produce electron-antineutrinos, so-called geo-neutrinos, the measurement of which near the earth's surface allows for a direct measure of the total radiogenic heat production in the earth. The KamLAND and Borexino experiments have both measured a geo-neutrino flux significantly greater than zero. As shown in these proceedings, more precise future measurements will significantly constrain earth composition models.

  6. Studying the Sun's Nuclear Furnace with a Neutrino Detector Spacecraft in Close Solar Orbit

    Science.gov (United States)

    Solomey, Nickolas

    2016-05-01

    A neutrino based detector in close solar orbit would have a neutrino flux 10,000x or more larger flux than on Earth and a smaller detector able to handle high rates with exception energy resolution could be used. We have studied the idea of operating such an experiment in close solar orbits that takes it off the ecliptic plane and in a solar orbit where the distance from the Sun will change distance. This neutrino detector on a space craft could do Solar Astrophysics studying the Solar nuclear furnace, basic nuclear physics and elementary particle physics; some of these ideas are new unique science that can only be preformed from a spacecraft. The harsh environment provides many challenges but if such a detector could be made to work it can be the next major step in this science study. How a small segmented detector can operate and preform in this environment to detect solar neutrinos will be elaborated upon using a combination of signal strength, fast signal timing, shielding and segmentation.

  7. Is solar neutrino capture rate correlated with sunspot number?

    Science.gov (United States)

    Bahcall, J. N.; Field, G. B.; Press, W. H.

    1987-01-01

    The statistical significance of the apparent correlation between sunspots and the observed neutrino rate is quantified. It is shown that the correlation depends almost entirely upon four low neutrino capture rates near the beginning of 1980. A calculation based on standard electroweak theory and neutrino production processes demonstrates that a correlation, if real, would be extremely puzzling on energetic grounds alone. It is concluded that measurements with the Cl-37 detector during the next sunspot cycle will be needed to show that there is a physical correlation, since the existing data are not statistically significant at a definitive level.

  8. Effects of magnetohydrodynamics matter density fluctuations on the solar neutrino resonant spin-flavor precession

    CERN Document Server

    Reggiani, N; Colonia, J H; De Holanda, P C

    1998-01-01

    Taking into account the stringent limits from helioseismology observations on possible matter density fluctuations described by magnetohydrodynamics theory, we find the corresponding time variations of solar neutrino survival probability due to the resonant spin-flavor precession phenomenon with amplitude of order O(10%). We discuss the physics potential of high statistics real time experiments, like as Superkamiokande, to observe the effects of such magnetohydrodynamics fluctuations on their data. We conclude that these observations could be thought as a test of the resonant spin-flavor precession solution to the solar neutrino anomaly.

  9. The chemical composition of the Sun from helioseismic and solar neutrino data

    CERN Document Server

    Villante, F L; Delahaye, F; Pinsonneault, M H

    2013-01-01

    We perform a quantitative analysis of the solar composition problem by using a statistical approach that allows us to combine the information provided by helioseimic and solar neutrino data in an effective way. We include in our analysis the helioseismic determinations of the surface helium abundance and of the depth of the convective envelope, the measurements of the $^7{\\rm Be}$ and $^8{\\rm B}$ neutrino fluxes, the sound speed profile inferred from helioseismic frequencies. We provide all the ingredients to describe how these quantities depend on the solar surface composition and to evaluate the (correlated) uncertainties in solar model predictions. We include errors sources that are not traditionally considered such as those from inversion of helioseismic data. We, then, apply the proposed approach to infer the chemical composition of the Sun. We show that the opacity profile of the Sun is well constrained by the solar observational properties. In the context of a two parameter analysis in which elements a...

  10. Violation of the Equivalence Principle in the light of the SNO and SK solar neutrino results

    CERN Document Server

    Raychaudhuri, A K; Raychaudhuri, Amitava; Sil, Arunansu

    2002-01-01

    The SNO result on charged current deuteron disintegration, the SuperKamiokande 1258-day data on electron scattering, and other solar neutrino results are used to revisit the model of neutrino oscillations driven by a violation of the equivalence principle. We use a chisq minimization technique to examine oscillation between the nu(e) and another active neutrino, both massless, and find that within the Standard Solar Model the fit to the SNO and SuperKamiokande spectra are moderately good while a very good fit is obtained when the absolute normalizations of the 8B and hep neutrino fluxes are allowed to vary. The best fit prefers large, but not maximal, mixing, essentially no hep neutrinos, and a 40% reduction in the 8B neutrino flux. The fit to the total rates from the different experiments is not encouraging but when the rates and spectra are considerd together the situation is much improved. We remark on the expectations of the VEP model for the neutral current measurements at SNO.

  11. Solar neutrinos and the influences of opacity, thermal instability, additional neutrino sources, and a central black hole on solar models

    Science.gov (United States)

    Stothers, R. B.; Ezer, D.

    1972-01-01

    Significant quantities that affect the internal structure of the sun are examined for factors that reduce the temperature near the sun's center. The four factors discussed are: opacity, central black hole, thermal instability, and additional neutrino sources.

  12. Constraints on flavor-dependent long range forces from solar neutrinos and KamLAND

    CERN Document Server

    Bandyopadhyay, A; Joshipura, A S; Bandyopadhyay, Abhijit; Dighe, Amol; Joshipura, Anjan S.

    2006-01-01

    Flavor-dependent long range (LR) leptonic forces, like those mediated by the $L_e-L_\\mu$ or $L_e -L_\\tau$ gauge bosons, constitute a minimal extension of the standard model that preserves its renormalizability. We study the impact of such interactions on the solar neutrino oscillations when the interaction range $R_{LR}$ is much larger than the Earth-Sun distance. The LR potential can dominate over the standard charged current potential inside the Sun in spite of strong constraints on the coupling $\\alpha$ of the LR force coming from the atmospheric neutrino data and laboratory search for new forces. We demonstrate that the solar and atmospheric neutrino mass scales do not get trivially decoupled even if $\\theta_{13}$ is vanishingly small. In addition, for $\\alpha \\gsim 10^{-52}$ and normal hierarchy, resonant enhancement of $\\theta_{13}$ results in nontrivial energy dependent effects on the $\

  13. Solar 8B and hep neutrino measurements from 1258 days of Super-Kamiokande data.

    Science.gov (United States)

    Fukuda, S; Fukuda, Y; Ishitsuka, M; Itow, Y; Kajita, T; Kameda, J; Kaneyuki, K; Kobayashi, K; Koshio, Y; Miura, M; Moriyama, S; Nakahata, M; Nakayama, S; Okada, A; Sakurai, N; Shiozawa, M; Suzuki, Y; Takeuchi, H; Takeuchi, Y; Toshito, T; Totsuka, Y; Yamada, S; Desai, S; Earl, M; Kearns, E; Messier, M D; Scholberg, K; Stone, J L; Sulak, L R; Walter, C W; Goldhaber, M; Barszczak, T; Casper, D; Gajewski, W; Kropp, W R; Mine, S; Liu, D W; Price, L R; Smy, M B; Sobel, H W; Vagins, M R; Ganezer, K S; Keig, W E; Ellsworth, R W; Tasaka, S; Kibayashi, A; Learned, J G; Matsuno, S; Takemori, D; Hayato, Y; Ishii, T; Kobayashi, T; Nakamura, K; Obayashi, Y; Oyama, Y; Sakai, A; Sakuda, M; Kohama, M; Suzuki, A T; Inagaki, T; Nakaya, T; Nishikawa, K; Haines, T J; Blaufuss, E; Dazeley, S; Lee, K B; Svoboda, R; Goodman, J A; Guillian, G; Sullivan, G W; Turcan, D; Habig, A; Hill, J; Jung, C K; Martens, K; Malek, M; Mauger, C; McGrew, C; Sharkey, E; Viren, B; Yanagisawa, C; Mitsuda, C; Miyano, K; Saji, C; Shibata, T; Kajiyama, Y; Nagashima, Y; Nitta, K; Takita, M; Yoshida, M; Kim, H I; Kim, S B; Yoo, J; Okazawa, H; Ishizuka, T; Etoh, M; Gando, Y; Hasegawa, T; Inoue, K; Ishihara, K; Maruyama, T; Shirai, J; Suzuki, A; Koshiba, M; Hatakeyama, Y; Ichikawa, Y; Koike, M; Nishijima, K; Fujiyasu, H; Ishino, H; Morii, M; Watanabe, Y; Golebiewska, U; Kielczewska, D; Boyd, S C; Stachyra, A L; Wilkes, R J; Young, K K

    2001-06-18

    Solar neutrino measurements from 1258 days of data from the Super-Kamiokande detector are presented. The measurements are based on recoil electrons in the energy range 5.0-20.0 MeV. The measured solar neutrino flux is 2.32+/-0.03(stat)+0.08-0.07(syst)x10(6) cm(-2) x s(-1), which is 45.1+/-0.5(stat)+1.6-1.4(syst)% of that predicted by the BP2000 SSM. The day vs night flux asymmetry (Phi(n)-Phi(d))/Phi(average) is 0.033+/-0.022(stat)+0.013-0.012(syst). The recoil electron energy spectrum is consistent with no spectral distortion. For the hep neutrino flux, we set a 90% C.L. upper limit of 40x10(3) cm(-2) x s(-1), which is 4.3 times the BP2000 SSM prediction.

  14. Measurement of the response of a Ga solar neutrino experiment to neutrinos from an 37Ar source

    CERN Document Server

    Abdurashitov, J N; Girin, S V; Gorbachev, V V; Gurkina, P P; Ibragimova, T V; Kalikhov, A V; Khairnasov, N G; Knodel, T V; Matveev, V A; Mirmov, I N; Shikhin, A A; Veretenkin, E P; Vermul, V M; Yants, V E; Zatsepin, G T; Bowles, T J; Elliott, S R; Teasdale, W A; Cleveland, B T; Haxton, W C; Wilkerson, J F; Nico, J S; Suzuki, A; Lande, K; Khomyakov, Y S; Poplavsky, V M; Popov, V V; Mishin, O V; Petrov, A N; Vasiliev, B A; Voronov, S A; Karpenko, A I; Maltsev, V V; Oshkanov, N N; Tuchkov, A M; Barsanov, V I; Janelidze, A A; Korenkova, A V; Kotelnikov, N A; Markov, S Y; Selin, V V; Shakirov, Z N; Zamyatina, A A; Zlokazov, S B; Khomyakov, Yu.S.

    2006-01-01

    An intense source of 37Ar was produced by the (n,alpha) reaction on 40Ca by irradiating 330 kg of calcium oxide in the fast neutron breeder reactor at Zarechny, Russia. The 37Ar was released from the solid target by dissolution in acid, collected from this solution, purified, sealed into a small source, and brought to the Baksan Neutrino Observatory where it was used to irradiate 13 tonnes of gallium metal in the Russian-American gallium solar neutrino experiment SAGE. Ten exposures of the gallium to the source, whose initial strength was 409 +/- 2 kCi, were carried out during the period April to September 2004. The 71Ge produced by the reaction 71Ga(nu_e,e^-)71Ge was extracted, purified, and counted. The measured production rate was 11.0 ^+1.0 _-0.9 (stat) +/- 0.6 (syst) atoms of 71Ge/d, which is 0.79 ^+0.09_-0.10 of the theoretically calculated production rate. When all neutrino source experiments with gallium are considered together, there is an indication the theoretical cross section has been overestimat...

  15. What can the SNO Neutral Current Rate teach us about the Solar Neutrino Anomaly

    CERN Document Server

    Bandyopadhyay, A; Goswami, S; Roy, D P; Bandyopadhyay, Abhijit; Choubey, Sandhya; Goswami, Srubabati

    2002-01-01

    We investigate how the anticipated neutral current rate from $SNO$ will sharpen our understanding of the solar neutrino anomaly. Quantitative analyses are performed with representative values of this rate in the expected range of $0.8 - 1.2$. This would provide a $5 - 10 \\sigma$ signal for $\

  16. Implications of the first neutral current data from SNO for Solar Neutrino Oscillation

    CERN Document Server

    Bandyopadhyay, A; Goswami, S; Roy, D P; Bandyopadhyay, Abhijit; Choubey, Sandhya; Goswami, Srubabati

    2002-01-01

    We perform model independent and model dependent analyses of solar neutrino data including the neutral current event rate from SNO. The inclusion of the first SNO NC data in the model independent analysis determines the allowed ranges of $^{8}{B}$ flux normalisation and the $\

  17. The effect of primordial hydrogen/helium fractionation on the solar neutrino flux

    Science.gov (United States)

    Wheeler, J. C.; Cameron, A. G. W.

    1975-01-01

    If hydrogen and helium are immiscible below some critical temperature, gravitational separation could occur in the proto-sun, resulting in a nearly pure helium core and a nearly pure hydrogen shell. We have constructed solar models according to this scenario and find the neutrino flux reduced to 1.5-3 SNU.

  18. Searches for sterile component with solar neutrinos and KamLAND

    CERN Document Server

    De Holanda, P C

    2002-01-01

    Possible mixing of the active and sterile neutrinos has been considered both in the single Delta m^2 approximation and in the case of more than one Delta m^2. We perform global fit of the available solar neutrino data with free boron neutrino flux in the single Delta m^2 context. The best fit value corresponds to zero fraction of sterile component eta=0. We get the upper bounds: eta<0.26 (0.64) at 1\\sigma (3 sigma). Due to degeneracy of parameters no one individual experiment restricts eta. The bound appears as an interplay of the SNO and Gallium as well as SuperKamiokande data. Future measurements of the NC/CC ratio at SNO can strengthen the bound down to eta<0.5 (3 sigma). If KamLAND confirms the LMA solution with its best fit point a combined analysis of the KamLAND and solar neutrino results will lead to eta<0.19 (0.56) at 1 sigma (3 sigma). We find that existence of sterile neutrino can explain the intermediate value of suppression of the KamLAND event rate: R_{KL}~0.75-0.90 in the case when mor...

  19. Background Study on Supernova Relic Neutrinos Search in SuperK-Gd

    CERN Document Server

    Zhang, Yang

    2016-01-01

    The detection of supernova relic neutrinos could provide precious information on the evolution of the universe, the formation of stars, the mechanism of supernova bursts and the related neutrino physics. Many experiments, such as Kamland, Borexino, Sudbury Neutrino Observatory and Super-Kamiokande have conducted searches for the supernova relic neutrinos. However, no supernova relic neutrino signal has been observed until now. This paper reports the background study on the supernova relic neutrinos search for the future neutrino experiment in SuperK-Gd project. The expected event rate for various background sources and supernova relic neutrino models are calculated, respectively.

  20. Global Analysis of the post-SNO Solar Neutrino Data for Standard and Non-Standard Oscillation Mechanisms

    CERN Document Server

    Gago, A M; De Holanda, P C; Nunokawa, H; Peres, O L G; Pleitez, V; Zukanovich-Funchal, R

    2002-01-01

    What can we learn from solar neutrino observations? Is there any solution to the solar neutrino anomaly which is favored by the present experimental panorama? After SNO results, is it possible to affirm that neutrinos have mass? In order to answer such questions we analyze the current available data from the solar neutrino experiments, including the recent SNO result, in view of many acceptable solutions to the solar neutrino problem based on different conversion mechanisms, for the first time, using the same statistical procedure. This allows us to do a direct comparison of the goodness of the fit among different solutions, from which we can discuss and conclude on the current status of each proposed dynamical mechanism. These solutions are based on different assumptions: (a) neutrino mass and mixing, (b) non-vanishing neutrino magnetic moment, (c) the existence of non-standard flavor-changing and non-universal neutrino interactions and (d) the tiny violation of the equivalence principle. We investigate the ...

  1. The stability of the MSW solution to the solar neutrino problem with respect to random matter density perturbations

    CERN Document Server

    Rossi, A

    1996-01-01

    We present a generalization of the resonant neutrino conversion in matter, including a random component in the matter density profile. The study is focused on the effect of such matter perturbations upon both large and small mixing angle MSW solutions to the solar neutrino problem. This is carried out both for the active-active \

  2. Energy Independent Solution to the Solar Neutrino Anomaly including the SNO data

    CERN Document Server

    Choubey, S; Roy, D P; Choubey, Sandhya; Goswami, Srubabati

    2002-01-01

    The global data on solar neutrino rates and spectrum, including the SNO charged current rate, can be explained by LMA, LOW or the energy independent solution -- corresponding to near-maximal mixing. All the three favour a mild upward renormalisation of the Cl rate. A mild downward shift of the $B$ neutrino flux is favoured by the energy independent and to a lesser extent the LOW solution, but not by LMA. Comparison with the ratio of SK elastic and SNO charged current scattering rates favours the LMA over the other two solutions, but by no more than $1.5\\sigma$.

  3. Environmental {sup 222}Rn as a background source in the solar neutrino experiment GALLEX

    Energy Technology Data Exchange (ETDEWEB)

    Wojcik, M. [Uniwersytet Jagiellonski, Cracow (Poland). Inst. Fizyki; BOREXINO

    1996-12-31

    The radiochemical neutrino experiment GALLEX is described. Its aim is to measure the flux of low energy solar neutrinos. In this experiment it is essential to suppress strongly the background of environmental origin, like charged cosmic rays, neutrons and gamma rays. In low-level radioactivity measurements performed in deep underground laboratory where flux of charged comic rays is strongly reduced, radon (Rn) exhaled from rock or concrete walls forms a most important strong, time-dependent background component. In this work the impact of Rn on the GALLEX experiment has been discussed and attempts to recognize and minimize its influence on the counter background were described. 63 refs, 22 figs, 11 tabs.

  4. Probing long-range leptonic forces with solar and reactor neutrinos

    CERN Document Server

    González-Garciá, M C; Massó, E; Zukanovich-Funchal, R

    2007-01-01

    In this work we study the phenomenological consequences of the existence of long-range forces coupled to lepton flavour numbers in solar neutrino oscillations. We study electronic forces mediated by scalar, vector or tensor neutral bosons and analyze their effect on the propagation of solar neutrinos as a function of the force strength and range. Under the assumption of one mass scale dominance, we perform a global analysis of solar and KamLAND neutrino data which depends on the two standard oscillation parameters, \\Delta m^2_{21} and \\tan^2\\theta_{12}, the force coupling constant, its range and, for the case of scalar-mediated interactions, on the neutrino mass scale as well. We find that, generically, the inclusion of the new interaction does not lead to a very statistically significant improvement on the description of the data in the most favored MSW LMA (or LMA-I) region. It does, however, substantially improve the fit in the high-\\Delta m^2 LMA (or LMA-II) region which can be allowed for vector and scal...

  5. Low-energy electronic recoil in xenon detectors by solar neutrinos

    CERN Document Server

    Chen, Jiunn-Wei; Liu, C -P; Wu, Chih-Pan

    2016-01-01

    Low-energy electronic recoil caused by solar neutrinos in multi-ton xenon detectors is an important subject not only because it is a source of the irreducible background for direct searches of weakly-interacting massive particles (WIMPs), but also because it provides a viable way to measure the solar $pp$ and $^{7}\\textrm{Be}$ neutrinos at the precision level of current standard solar model predictions. In this work we perform $\\textit{ab initio}$ many-body calculations for the structure, photoionization, and neutrino-ionization of xenon. It is found that the atomic binding effect yields a sizable suppression to the neutrino-electron scattering cross section at low recoil energies. Compared with the previous calculation based on the free electron picture, our calculated event rate of electronic recoil in the same detector configuration is reduced by about $25\\%$. We present in this paper the electronic recoil rate spectrum in the energy window of 100 eV - 30 keV with the standard per ton per year normalizatio...

  6. A Comment on the Suspected Solar Neutrino-Solar Activity Connection

    Science.gov (United States)

    Wilson, Robert M.

    1994-01-01

    Recently, it has been proposed that there exists a highly statistically significant (at greater than or equal to 98% level of confidence) relationship between Ar-37 production rate (viz., solar neutrinos) and the Ap geomagnetic index (viz., solar particles), based on the (chi)-square goodness-of-fit test and correlation analysis, for the interval 1970-1990. While a relationship between the two parameters, indeed, seems to be discernible, the strength of the relationship has been overstated. Instead of being significant at the afore-mentioned level of confidence, the relationship is found to be significant at only greater than or equal to 95% level of confidence, based on Yates' modification to the (chi)-square test for 2 x 2 contingency tables. Likewise, while correlation analysis yields a value of r = 0.2691, it is important to note that such a value suggests that only about 7% of the variance can be 'explained' by the inferred correlation and that the remaining 93% of the variance must be attributed to other sources.

  7. The possibility of forming an inhomogeneous Sun and the solar neutrino effect

    Science.gov (United States)

    Levy, E. H.; Ruzmaikina, T. V.

    1994-01-01

    Recent observations confirm that the flux of neutrinos from the interior of the Sun is significantly less than what is expected on the basis of solar models. It has long been known that a low neutrino flux could result from a temperature in the Sun's core lower than the approximately 1.5 x 10(exp 7) K central temperature given by standard solar models. A low central temperature could occur if the solar interior were depleted in the so-called metals -- atomic species heavier than helium -- resulting in lower internal opacity. In this case, chemical abundances measured in the solar convection zone would be unrepresentative of the deep-interior abundances. The possibility of a compositionally inhomogeneous Sun has usually been discarded on the basis of cosmogonical arguments against the formation of such nonhomogeneity. This paper suggests that compositional nonhomogeneity could have arisen through unremarkable physical processes during the formation of the Sun, and that a compositionally inhomogeneous Sun remains a viable possibility for investigation of the solar neutrino problem.

  8. Independent Measurement of the Total Active B8 Solar Neutrino Flux Using an Array of He3 Proportional Counters at the Sudbury Neutrino Observatory

    Science.gov (United States)

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

    2008-09-01

    The Sudbury Neutrino Observatory (SNO) used an array of He3 proportional counters to measure the rate of neutral-current interactions in heavy water and precisely determined the total active (νx) B8 solar neutrino flux. This technique is independent of previous methods employed by SNO. The total flux is found to be 5.54-0.31+0.33(stat)-0.34+0.36(syst)×106cm-2s-1, in agreement with previous measurements and standard solar models. A global analysis of solar and reactor neutrino results yields Δm2=7.59-0.21+0.19×10-5eV2 and θ=34.4-1.2+1.3 degrees. The uncertainty on the mixing angle has been reduced from SNO’s previous results.

  9. An Independent Measurement of the Total Active 8B Solar Neutrino Flux Using an Array of 3He Proportional Counters at the Sudbury Neutrino Observatory

    CERN Document Server

    Aharmim, B; Amsbaugh, J F; Anthony, A E; Banar, J; Barros, N; Beier, E W; Bellerive, A; Beltran, B; Bergevin, M; Biller, S D; Boudjemline, K; Boulay, M G; Bowles, T J; Browne, M C; Bullard, T V; Burritt, T H; Cai, B; Chan, Y D; Chauhan, D; Chen, M; Cleveland, B T; Cox-Mobrand, G A; Currat, C A; Dai, X; Deng, H; Detwiler, J; Di Marco, M; Doe, P J; Doucas, G; Drouin, P L; Duba, C A; Duncan, F A; Dunford, M; Earle, E D; Elliott, S R; Evans, H C; Ewan, G T; Farine, J; Fergani, H; Fleurot, F; Ford, R J; Formaggio, J A; Fowler, M M; Gagnon, N; Germani, J V; Goldschmidt, A; Goon, J T M; Graham, K; Guillian, E; Habib, S; Hahn, R L; Hallin, A L; Hallman, E D; Hamian, A A; Harper, G C; Harvey, P J; Hazama, R; Heeger, K M; Heintzelman, W J; Heise, J; Helmer, R L; Henning, R; Hime, A; Howard, C; Howe, M A; Huang, M; Jagam, P; Jamieson, B; Jelley, N A; Keeter, K J; Klein, J R; Kormos, L L; Kos, M; Krüger, A; Kraus, C; Krauss, C B; Kutter, T; Kyba, C C M; Lange, R; Law, J; Lawson, I T; Lesko, K T; Leslie, J R; Loach, J C; MacLellan, R; Majerus, S; Mak, H B; Maneira, J; Martin, R; McBryde, K; McCauley, N; McDonald, A B; McGee, S; Miin, C; Miller, G G; Miller, M L; Monreal, B; Monroe, J; Morissette, B; Myers, A; Nickel, B G; Noble, A J; Oblath, N S; O'Keeffe, H M; Ollerhead, R W; Orebi Gann, G D; Oser, S M; Ott, R A; Peeters, S J M; Poon, A W P; Prior, G; Reitzner, S D; Rielage, K; Robertson, B C; Robertson, R G H; Rollin, E; Schwendener, M H; Secrest, J A; Seibert, S R; Simard, O; Simpson, J J; Sinclair, L; Skensved, P; Smith, M W E; Steiger, T D; Stonehill, L C; Tesic, G; Thornewell, P M; Tolich, N; Tsui, T; Tunnell, C D; Van Wechel, T; Van Berg, R; Van Devender, B A; Virtue, C J; Walker, T J; Wall, B L; Waller, D; Wan Chan Tseung, H; Wendland, J; West, N; Wilhelmy, J B; Wilkerson, J F; Wilson, J R; Wouters, J M; Wright, A; Yeh, M; Zhang, F; Zuber, K

    2008-01-01

    The Sudbury Neutrino Observatory (SNO) used an array of 3He proportional counters to measure the rate of neutral-current interactions in heavy water and precisely determined the total active (nu_x) 8B solar neutrino flux. This technique is independent of previous methods employed by SNO. The total flux is found to be 5.54(+0.33/-0.31 stat, +0.36/-0.34 syst) x 10^6 cm^-2 s^-1, in agreement with previous measurements and standard solar models. A global analysis of solar and reactor neutrino results yields Delta m^2 = 7.94(+0.42/-0.26) x 10^-5 eV^2 and theta = 33.8(+1.4/-1.3) degrees. The uncertainty on the mixing angle has been reduced from SNO's previous results.

  10. Independent measurement of the total active 8B solar neutrino flux using an array of 3He proportional counters at the Sudbury Neutrino Observatory.

    Science.gov (United States)

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

    2008-09-12

    The Sudbury Neutrino Observatory (SNO) used an array of 3He proportional counters to measure the rate of neutral-current interactions in heavy water and precisely determined the total active (nu_x) 8B solar neutrino flux. This technique is independent of previous methods employed by SNO. The total flux is found to be 5.54_-0.31;+0.33(stat)-0.34+0.36(syst)x10(6) cm(-2) s(-1), in agreement with previous measurements and standard solar models. A global analysis of solar and reactor neutrino results yields Deltam2=7.59_-0.21;+0.19x10(-5) eV2 and theta=34.4_-1.2;+1.3 degrees. The uncertainty on the mixing angle has been reduced from SNO's previous results.

  11. New limits on neutrino magnetic moments from low energy neutrino data

    CERN Document Server

    Canas, B C; Parada, A; Tortola, M; Valle, J W F

    2016-01-01

    Here we give a brief review on the current bounds on the general Majorana transition neutrino magnetic moments (TNMM) which cover also the conventional neutrino magnetic moments (NMM). Leptonic CP phases play a key role in constraining TNMMs. While the Borexino experiment is the most sensitive to the TNMM magnitudes, one needs complementary information from reactor and accelerator experiments in order to probe the complex CP phases.

  12. Neutrino magnetic moment

    Energy Technology Data Exchange (ETDEWEB)

    Chang, D. (Northwestern Univ., Evanston, IL (USA). Dept. of Physics and Astronomy Fermi National Accelerator Lab., Batavia, IL (USA)); Senjanovic, G. (Zagreb Univ. (Yugoslavia). Dept. of Theoretical Physics)

    1990-01-01

    We review attempts to achieve a large neutrino magnetic moment ({mu}{sub {nu}} {le} 10{sup {minus}11}{mu}{sub B}), while keeping neutrino light or massless. The application to the solar neutrino puzzle is discussed. 24 refs.

  13. Neutrino anomalies without oscillations

    Indian Academy of Sciences (India)

    Sandip Pakvasa

    2000-01-01

    I review explanations for the three neutrino anomalies (solar, atmospheric and LSND) which go beyond the `conventional' neutrino oscillations induced by mass-mixing. Several of these require non-zero neutrino masses as well.

  14. Measurement of gamow-teller strength for 176Yb --> 176Lu and the efficiency of a solar neutrino detector

    Science.gov (United States)

    Bhattacharya; Goodman; Raghavan; Palarczyk; Garcia; Rapaport; van Heerden IJ; Zupranski

    2000-11-20

    We report a 0 degrees 176Yb(p,n)176Lu measurement at IUCF where we used 120 and 160 MeV protons and the energy dependence method to determine Gamow-Teller (GT) matrix elements relative to the model independent Fermi matrix element. The data show that there is an isolated concentration of GT strength in the low-lying 1(+) states making the proposed Low Energy Neutrino Spectroscopy detector (based on neutrino captures on 176Yb) sensitive to pp and 7Be neutrinos and a promising detector to resolve the solar neutrino problem.

  15. Solar neutrino results (from radio-chemical and water Cherenkov detectors)

    CERN Document Server

    Suzuki, Y

    2001-01-01

    Recent results on solar neutrino measurements are discussed. The results from radio-chemical experiments are briefly summarized. The new data from 1117 effective days of Super-Kamiokande shows that the spectrum shape agrees with that expected from the convoluted effect of the sup 8 B-neutrino spectrum, the recoil electron spectrum of neutrino electron scattering and the detector responses and that there is a 3.4% difference between the day- and night-time fluxes, but statistically not significant. There is no strong smoking gun evidence for oscillation yet, however those precise measurements of the spectrum shape and day/night fluxes have given a constraint on the oscillation parameters, indicating at 95% confidence level that the large mixing angles solutions (MSW LMA and LOW) are preferable.

  16. A search for evidence of solar rotation in Super-Kamiokande solar neutrino dataset

    Science.gov (United States)

    Desai, Shantanu; Liu, Dawei W.

    2016-09-01

    We apply the generalized Lomb-Scargle (LS) periodogram, proposed by Zechmeister and Kurster, to the solar neutrino data from Super-Kamiokande (Super-K) using data from its first five years. For each peak in the LS periodogram, we evaluate the statistical significance in two different ways. The first method involves calculating the False Alarm Probability (FAP) using non-parametric bootstrap resampling, and the second method is by calculating the difference in Bayesian Information Criterion (BIC) between the null hypothesis, viz. the data contains only noise, compared to the hypothesis that the data contains a peak at a given frequency. Using these methods, we scan the frequency range between 7-14 cycles per year to look for any peaks caused by solar rotation, since this is the proposed explanation for the statistically significant peaks found by Sturrock and collaborators in the Super-K dataset. From our analysis, we do confirm that similar to Sturrock et al, the maximum peak occurs at a frequency of 9.42/year, corresponding to a period of 38.75 days. The FAP for this peak is about 1.5% and the difference in BIC (between pure white noise and this peak) is about 4.8. We note that the significance depends on the frequency band used to search for peaks and hence it is important to use a search band appropriate for solar rotation. However, The significance of this peak based on the value of BIC is marginal and more data is needed to confirm if the peak persists and is real.

  17. Neutrino 2004: Collection of Presentations

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-07-01

    The scientific program covers the latest developments in neutrino physics, astrophysics and related topics through a set of invited talks and 2 poster sessions. The following issues are addressed: - solar neutrinos, - atmospheric neutrinos, - short and long baseline experiments, - neutrino oscillations, - double beta decay, - direct neutrino mass limits, - theory for neutrino masses, neutrino telescopes and ultra-high energy neutrinos, - dark matter searches, - neutrino in astrophysics and cosmology, and - future projects beams and experiments.

  18. Model independent determination of the solar neutrino spectrum with and without MSW

    CERN Document Server

    Hata, N; Hata, Naoya; Langacker, Paul

    1995-01-01

    Besides the opportunity for discovering new neutrino physics, solar neutrino measurements provide a sensitive probe of the solar interior, and thus a rigorous test of solar model predictions. We present model independent determinations of the neutrino spectrum by using relevant flux components as free parameters subject only to the luminosity constraint. (1) Without the Mikheyev-Smirnov-Wolfenstein (MSW) effect, the best fit for the combined data is poor. Furthermore, the data indicate a severe suppression of the ^7Be flux relative to the ^8B, contradicting both standard and nonstandard solar models in general; the pp flux takes its maximum value allowed by the luminosity constraint. This pathology consistently appears even if we ignore any one of the three data. (2) In the presence of the two-flavor MSW effect, the current constraint on the initial ^8B flux is weak, but consistent with the SSM and sufficient to exclude nonstandard models with small ^8B fluxes. No meaningful constraint is obtained for the oth...

  19. Update of the solar neutrino oscillation analysis with the 766 Ty KamLAND spectrum

    CERN Document Server

    Bandyopadhyay, A; Goswami, S; Petcov, S T; Roy, D P; Bandyopadhyay, Abhijit; Choubey, Sandhya; Goswami, Srubabati

    2004-01-01

    We investigate the impact of the observed spectral distortion in the 766.3 Ty KamLAND data in sharpening the allowed areas in solar neutrino oscillation parameter space. We study the robustness of the allowed regions and mutual consistency between different data sets by doing two generation neutrino oscillation global fits by removing one of the solar neutrino experiments from the analysis. We also examine the change if any in the bound on $\\theta_{13}$ from a three generation analysis with the inclusion of the new KamLAND data. We find that the precision of $\\Delta m^2_{21}$ improves significantly with the new KamLAND data in both two and three generation analysis but there is still scope for improvement for the precision of $\\theta_{12}$. The combined solar and KamLAND data excludes the high-LMA solution at the 4$\\sigma$ level in a one parameter fit. The maximal mixing solution is disfavoured to a greater extent by the new KamLAND data and the solar + KamLAND combination excludes it at about 6$\\sigma$. We d...

  20. Generalized Lomb-Scargle periodogram analysis of Super-Kamiokande and Sudbury Neutrino Observatory solar neutrino datasets

    CERN Document Server

    Desai, Shantanu

    2016-01-01

    We apply the generalized Lomb-Scargle (LS) periodogram proposed by Zechmeister and Kurster, to the solar neutrino data from Super-Kamiokande (Super-K) using data from its first five years, and to Sudbury Neutrino Observatory (SNO) on data from both its salt and $\\mathrm{D_2O}$ phases, in order to detect periodicities in these datasets. For each peak in the LS periodogram, we evaluate the statistical significance in two different ways. The first method involves calculating the False Alarm Probability (FAP) using non-parametric bootstrap resampling, and the second method is by calculating the difference in Bayesian Information Criterion (BIC) between the null hypothesis, viz. the data contains only noise, compared to the hypothesis that the data contains a peak at a given frequency. Using these methods, we assess the significance of various claims in the literature of sinusoidal modulations in the Super-K and SNO datasets. For the Super-K dataset (binned in 5-day intervals), the only marginally significant peak...

  1. Constraints from Solar and Reactor Neutrinos on Unparticle Long-Range Forces

    CERN Document Server

    González-Garciá, M C; Funchal, R Zukanovich

    2008-01-01

    We have investigated the impact of long-range forces induced by unparticle operators of scalar, vector and tensor nature coupled to fermions in the interpretation of solar neutrinos and KamLAND data. If the unparticle couplings to the neutrinos are mildly non-universal, such long-range forces will not factorize out in the neutrino flavour evolution. As a consequence large deviations from the observed standard matter-induced oscillation pattern for solar neutrinos would be generated. In this case,severe limits can be set on the infrared fix point scale, $\\Lambda_u$, and the new physics scale, $M$, as a function of the ultraviolet ($d_{\\rm UV}$) and anomalous ($d$) dimension of the unparticle operator. For a scalar unparticle, for instance, assuming the non-universality of the lepton couplings to unparticles to be of the order of a few per mil we find that, for $d_{\\rm UV}=3$ and $d=1.1$, $M$ is constrained to be $M> 10^{9}$ TeV ($M> 10^{10}$ TeV) if $\\Lambda_u =$ 1 TeV (10 TeV). For given values of $\\Lambda_u$...

  2. On the detection of neutrinos from solar flares using pion-decay photons to provide a time window template

    CERN Document Server

    de Wasseige, G; van Eijndhoven, N; Evenson, P; Klein, K -L

    2015-01-01

    Since the end of the eighties and in response to a reported increase in the total neutrino flux in the Homestake experiment in coincidence with solar flares, solar neutrino detectors have searched for solar flare signals. Even though these detectors have used different solar flare samples and analyses, none of them has been able to confirm the possible signal seen by Homestake. Neutrinos from the decay of mesons, which are themselves produced in collisions of accelerated ions with the solar atmosphere would provide a novel window on the underlying physics of the hadronic acceleration and interaction processes during solar flares. Solar flare neutrino flux measurements would indeed help to constrain current parameters such as the composition of the accelerated flux, the proton/ion spectral index and the high energy cutoff or the magnetic configuration in the interaction region. We describe here a new way to search for these neutrinos by considering a specific solar flare sample and a data driven time window te...

  3. Analysis of Solar Neutrino Data from Super-Kamiokande I and II

    Directory of Open Access Journals (Sweden)

    Hans J. Haubold

    2014-03-01

    Full Text Available We are going back to the roots of the original solar neutrino problem: the analysis of data from solar neutrino experiments. The application of standard deviation analysis (SDA and diffusion entropy analysis (DEA to the Super-Kamiokande I and II data reveals that they represent a non-Gaussian signal. The Hurst exponent is different from the scaling exponent of the probability density function, and both the Hurst exponent and scaling exponent of the probability density function of the Super-Kamiokande data deviate considerably from the value of 0.5, which indicates that the statistics of the underlying phenomenon is anomalous. To develop a road to the possible interpretation of this finding, we utilize Mathai’s pathway model and consider fractional reaction and fractional diffusion as possible explanations of the non-Gaussian content of the Super-Kamiokande data.

  4. Measurement of the rate of nu(e) + d --> p + p + e(-) interactions produced by (8)B solar neutrinos at the Sudbury Neutrino Observatory.

    Science.gov (United States)

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

    2001-08-13

    Solar neutrinos from (8)B decay have been detected at the Sudbury Neutrino Observatory via the charged current (CC) reaction on deuterium and the elastic scattering (ES) of electrons. The flux of nu(e)'s is measured by the CC reaction rate to be straight phi(CC)(nu(e)) = 1.75 +/- 0.07(stat)(+0.12)(-0.11)(syst) +/- 0.05(theor) x 10(6) cm(-2) s(-1). Comparison of straight phi(CC)(nu(e)) to the Super-Kamiokande Collaboration's precision value of the flux inferred from the ES reaction yields a 3.3 sigma difference, assuming the systematic uncertainties are normally distributed, providing evidence of an active non- nu(e) component in the solar flux. The total flux of active 8B neutrinos is determined to be 5.44+/-0.99 x 10(6) cm(-2) s(-1).

  5. No role for neutrons, muons and solar neutrinos in the DAMA annual modulation results

    Energy Technology Data Exchange (ETDEWEB)

    Bernabei, R.; D' Angelo, S.; Di Marco, A. [Universita di Roma ' ' Tor Vergata' ' , Dipt. di Fisica, Rome (Italy); INFN, sez. Roma ' ' Tor Vergata' ' , Rome (Italy); Belli, P. [INFN, sez. Roma ' ' Tor Vergata' ' , Rome (Italy); Cappella, F.; Caracciolo, V.; Cerulli, R. [INFN, Laboratori Nazionali del Gran Sasso, Assergi (Italy); Dai, C.J.; He, H.L.; Kuang, H.H.; Ma, X.H.; Sheng, X.D.; Wang, R.G. [Chinese Academy of Sciences, Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, P.O. Box 918/3, Beijing (China); D' Angelo, A.; Incicchitti, A. [Universita di Roma ' ' La Sapienza' ' , Dipt. di Fisica, Rome (Italy); INFN, sez. Roma, Rome (Italy); Montecchia, F. [INFN, sez. Roma ' ' Tor Vergata' ' , Rome (Italy); Universita di Roma ' ' Tor Vergata' ' , Dipt. di Ingegneria Civile e Ingegneria Informatica, Rome (Italy); Ye, Z.P. [Chinese Academy of Sciences, Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, P.O. Box 918/3, Beijing (China); University of Jing Gangshan, Ji' an, Jiangxi (China)

    2014-12-01

    This paper summarizes in a simple and intuitive way why the neutrons, the muons and the solar neutrinos cannot give any significant contribution to the DAMA annual modulation results. A number of these elements have already been presented in individual papers; they are recalled here together with few simple considerations which demonstrate the incorrectness of the claim reported in Davis (PRL 113:081302, 2014). (orig.)

  6. Upper Bound on θ13 from Combined Analysis of Solar Neutrino Data Together with Reactor Data

    Directory of Open Access Journals (Sweden)

    Deniz Yılmaz

    2013-12-01

    Full Text Available A joint analysis of solar neutrino data together with the new KamLAND data is presented with different confidence intervals and sin2(2θ13 values. It is investigated how the allowed regions are effected in those cases. Limits on sin2(2θ13 value are found at different confidence level intervals: sin2(2θ13 < 0.19, 0.23 at % 90 CL and % 95 CL respectively.

  7. Reducing the solar neutrino background in dark matter searches using polarized helium-3

    Science.gov (United States)

    Franarin, Tarso; Fairbairn, Malcolm

    2016-09-01

    Future dark matter detectors plan to have sensitivities such that solar neutrinos will start to become a problematic background. In this work, we show that a polarized helium-3 detector would, in principle, be able to eliminate 98% of these events when the orientation of the polarization axis is antiparallel to the direction of the Sun. We comment on the possible improvement in sensitivity of dark matter direct detection experiments due to this effect and the feasibility of building such a detector.

  8. Detecting electron neutrinos from solar dark matter annihilation by JUNO

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Wan-Lei [Institute of High Energy Physics, Chinese Academy of Sciences,P.O. Box 918, Beijing 100049 (China)

    2016-01-21

    We explore the electron neutrino signals from light dark matter (DM) annihilation in the Sun for the large liquid scintillator detector JUNO. In terms of the spectrum features of three typical DM annihilation channels χχ→νν-bar,τ{sup +}τ{sup −},bb-bar, we take two sets of selection conditions to calculate the expected signals and atmospheric neutrino backgrounds based on the Monte Carlo simulation data. Then the JUNO sensitivities to the spin independent DM-nucleon and spin dependent DM-proton cross sections are presented. It is found that the JUNO projected sensitivities are much better than the current spin dependent direct detection experimental limits for the νν-bar and τ{sup +}τ{sup −} channels. In the spin independent case, the JUNO will give the better sensitivity to the DM-nucleon cross section than the LUX and CDMSlite limits for the νν-bar channel with the DM mass lighter than 6.5 GeV. If the νν-bar or τ{sup +}τ{sup −} channel is dominant, the future JUNO results are very helpful for us to understand the tension between the DAMA annual modulation signal and other direct detection exclusions.

  9. Solar neutrinos: the SNO salt phase results and physics of conversion

    CERN Document Server

    De Holanda, P C

    2003-01-01

    We have performed analysis of the solar neutrino data including results from the SNO salt phase as well as the combined analysis of the solar and the KamLAND results. The best fit values of neutrino parameters are Delta m^2 = 7.13e-5 eV^2, tan^2\\theta = 0.39 with boron flux f_B = 1.042. New SNO results strongly disfavor maximal mixing and the h-LMA region (Delta m^2 > 1e-4 eV^2) which is now accepted at 3-sigma level. We find the 3-sigma upper bounds: Delta m^2 4.7e-5 eV^2. Non-zero 13-mixing does not change these results significantly. The present data determine quantitatively the physical picture of the solar neutrino conversion. At high energies relevant for SNO and Super-Kamiokande the deviation of effective survival probability from non-oscillatory value is about 10 - 14%. The oscillation effect contribution to this difference is about 10% and the Earth regeneration about 3-4 %. At low energies (E < 1 MeV) the matter corrections to vacuum oscillation effect are below 5%. The predictions for the forth...

  10. Solar neutrino results and Violation of the Equivalence Principle An analysis of the existing data and predictions for SNO

    CERN Document Server

    Majumdar, D; Sil, A; Majumdar, Debasish; Raychaudhuri, Amitava; Sil, Arunansu

    2001-01-01

    Violation of the Equivalence Principle (VEP) can lead to neutrino oscillation through the non-diagonal coupling of neutrino flavor eigenstates with the gravitational field. The neutrino energy dependence of this oscillation probability is different from that of the usual mass-mixing neutrino oscillations. In this work we explore, in detail, the viability of the VEP hypothesis as a solution to the solar neutrino problem in a two generation scenario with both the active and sterile neutrino alternatives, choosing these states to be massless. To obtain the best-fit values of the oscillation parameters we perform a chi square analysis for the total rates of solar neutrinos seen at the Chlorine (Homestake), Gallium (Gallex and SAGE), Kamiokande, and SuperKamiokande (SK) experiments. We find that the goodness of these fits is never satisfactory. It markedly improves if the Chlorine data is excluded from the analysis, especially for VEP transformation to sterile neutrinos. The 1117-day SK data for recoil electron sp...

  11. Planetary influence on the young Sun's evolution: the solar neutrino probe

    CERN Document Server

    Lopes, Ilidio

    2013-01-01

    Recent observations of solar twin stars with planetary systems like the Sun, have uncovered that these present a peculiar surface chemical composition. This is believed to be related to the formation of earth-like planets. This suggests that twin stars have a radiative interior that is richer in heavy elements than their envelopes. Moreover, the current standard solar model does not fully agree with the helioseismology data and solar neutrino flux measurements. In this work, we find that this agreement can improve if the Sun has mass loss during the pre-main sequence, as was previously shown by other groups. Despite this better agreement, the internal composition of the Sun is still uncertain, especially for elements heavier than helium. With the goal of inferring the chemical abundance of the solar interior, we tested several chemical compositions. We found that heavy element abundances influence the sound speed and solar neutrinos equally. Nevertheless, the carbon-nitrogen-oxygen (CNO;13N, 15O and 17F) neut...

  12. Effects of heavy-element settling on solar neutrino fluxes and interior structure

    Science.gov (United States)

    Proffitt, Charles R.

    1994-01-01

    We consider the effects of gravitational settling of both He and heavier elements on the predicted solar neutrino fluxes and interior sound speed and density profiles. We find that while the structural changes that result from the inclusion of both He and heavy-element settling are only slightly larger than the changes resulting from the inclusion of He settling alone, the additional increases in expected neutrino fluxes are of comparable size. Our preferred model with both He and heavy-element settling has neutrino count rates of 9.0 SNU for Cl-37 detectors and 137 SNU for Ga-71 detectors, as compared to 7.1 and 127 SNU for a comparable model without any diffusive separation, or 8.0 and 132 SNU for a model that includes He settling alone. We suggest that the correction factors by which the predicted neutrino fluxes of solar models calculated without including the effects of diffusion should be multiplied are 1.25 +/- 0.08 for Cl detectors, 1.07 +/- 0.02 for Ga detectors, and 1.28 +/- 0.09 for the B-8 flux (1 sigma errors). Comparison of internal sound speed and density profiles strongly suggests that the additional changes in calculated p-mode oscillation frequencies due to the inclusion of heavy-element settling will be small compared to the changes that result from He settling alone, especially for the higher degree modes. All models with diffusive separation give much better agreement with the observed depth of the convection zone than do nondiffusive models. The model that includes both He and heavy-element settling requires an initial He mass fraction Y = 0.280 and has a surface He abundance of Y = 0.251 at the solar age.

  13. Large mixing angle solution to the solar neutrino problem and random matter density perturbations

    CERN Document Server

    Guzzo, M M; Reggiani, N

    2003-01-01

    There are reasons to believe that mechanisms exist in the solar interior which lead to random density perturbations in the resonant region of the Large Mixing Angle solution to the solar neutrino problem. We find that, in the presence of these density perturbations, the best fit point in the (sin^2(2\\theta), Delta_m^2) parameter space moves to smaller values, compared with the values obtained for the standard LMA solution. Combining solar data with KamLAND results, we find a new compatibility region, which we call VERY-LOW LMA, where sin^2(2\\theta) ~ 0.6 and Delta_m^2~2e-5 eV^2, for random density fluctuations of order 5% < \\xi< 8%. We argue that such values of density fluctuations are still allowed by helioseismological observations at small scales of order 10 - 1000 km deep inside the solar core.

  14. Theoretical Constraints on the Vacuum Oscillation Solution to the Solar Neutrino Problem

    CERN Document Server

    Casas, J A; Ibarra, Alejandro; Navarro, I

    1999-01-01

    The vacuum oscillation (VO) solution to the solar anomaly requires an extremely small neutrino mass splitting, Delta m^2_{sol}\\leq 10^{-10} eV^2. We study under which circumstances this small splitting (whatever its origin) is or is not spoiled by radiative corrections. The results depend dramatically on the type of neutrino spectrum. If m_1^2 \\sim m_2^2 \\geq m_3^2, radiative corrections always induce too large mass splittings. Moreover, if m_1 and m_2 have equal signs, the solar mixing angle is driven by the renormalization group evolution to very small values, incompatible with the VO scenario (however, the results could be consistent with the small-angle MSW scenario). If m_1 and m_2 have opposite signs, the results are analogous, except for some small (though interesting) windows in which the VO solution may be natural with moderate fine-tuning. Finally, for a hierarchical spectrum of neutrinos, m_1^2 << m_2^2 << m_3^2, radiative corrections are not dangerous, and therefore this scenario is th...

  15. A non-resonant dark-side solution to the solar neutrino problem

    CERN Document Server

    Miranda, O G; Rashba, T I; Semikoz, V B; Valle, José W F

    2001-01-01

    We re-analyse spin-flavour precession solutions to the solar neutrino problem in the light of the recent SNO CC result as well as the 1258-day Super-Kamiokande data and the upper limit on solar anti-neutrinos. In a self-consistent magneto-hydrodynamics approach the resulting scheme has only 3 effective parameters: $\\Delta m^2$, $\\muB_\\perp$ and the neutrino mixing angle $\\theta$. We show how a rates-only analysis slightly favours spin-flavour precession (SFP) solutions over oscillations (OSC). In addition to the resonant solution (RSFP for short), there is a new non-resonant solution (NRSFP) in the ``dark-side''. Both RSFP and NRSFP lead to flat recoil energy spectra in excellent agreement with the latest SuperKamiokande data. We also show that the presence of a magnetic field at the required level of 80 KGauss eliminates all large mixing solutions other than the so-called LMA solution.

  16. Solar 8B and hep Neutrino Measurements from 1258 Days of Super-Kamiokande Data

    CERN Document Server

    Fukuda, S; Ishitsuka, M; Itow, Y; Kajita, T; Kameda, J; Kaneyuki, K; Kobayashi, K; Koshio, Y; Miura, M; Moriyama, S; Nakahata, M; Nakayama, S; Okada, A; Sakurai, N; Shiozawa, M; Suzuki, Y; Takeuchi, H; Takeuchi, Y; Toshito, T; Totsuka, Y; Yamada, S; Desai, S V; Earl, M A; Kearns, E T; Messier, M D; Scholberg, K; Stone, J L; Sulak, Lawrence R; Walter, C W; Goldhaber, M; Barszczak, T; Casper, David William; Gajewski, W; Kropp, W R; Mine, S; Liu, D W; Price, L R; Smy, M B; Sobel, H W; Vagins, M R; Ganezer, K S; Keig, W E; Ellsworth, R W; Tasaka, S; Kibayashi, A; Learned, J G; Matsuno, S; Takemori, D; Hayato, Y; Ishii, T; Kobayashi, T; Nakamura, K; Obayashi, Y; Oyama, Y; Sakai, A; Sakuda, M; Kohama, M; Suzuki, A T; Inagaki, T; Nakaya, T; Nishikawa, K; Haines, T J; Blaufuss, E; Dazeley, S A; Lee, K B; Svoboda, R; Chen, M L; Goodman, J A; Guillian, G; Sullivan, G W; Turcan, D; Habig, A; Hill, J; Jung, C K; Martens, K; Malek, M; Mauger, C; McGrew, C; Sharkey, E; Viren, B M; Yanagisawa, C; Mitsuda, C; Miyano, K; Saji, C; Shibata, T; Kajiyama, Y; Nagashima, Y; Nitta, K; Takita, M; Yoshida, M; Kim, H I; Kim, S B; Yoo, J; Okazawa, H; Ishizuka, T; Etoh, M; Gando, Y; Hasegawa, T; Inoue, K; Ishihara, K; Maruyama, T; Shirai, J; Suzuki, A; Koshiba, M; Hatakeyama, Y; Ichikawa, Y; Koike, M; Nishijima, K; Fujiyasu, H; Ishino, H; Morii, M; Watanabe, Y; Golebiewska, U; Kielczewska, D; Boyd, S C; Stachyra, A L; Wilkes, R J; Young, K K

    2001-01-01

    Solar neutrino measurements from 1258 days of data from the Super-Kamiokande detector are presented. The measurements are based on recoil electrons in the energy range 5.0-20.0MeV. The measured solar neutrino flux is 2.32 +- 0.03(stat.) +0.08-0.07(sys.)*10^6cm^{-2}s^{-1}, which is 45.1+-0.5(stat.)+1.6-1.4(sys.)% of that predicted by the BP2000 SSM. The day vs night flux asymmetry is 0.033+-0.022(stat.)+0.013-0.012(sys .). The recoil electron energy spectrum is consistent with no spectral distortion (\\chi^2/d.o.f. = 19.0/18). The seasonal variation of the flux is consistent with that expected from the eccentricity of the Earth's orbit (\\chi^2/d.o.f. = 3.7/7). For the hep neutrino flux, we set a 90% C.L. upper limit of 40 *10^3cm^{-2}s^{-1}, which is 4.3 times the BP2000 SSM prediction.

  17. Precise Measurement of the Solar Neutrino Day/Night and Seasonal Variation in Super-Kamiokande-I

    CERN Document Server

    Smy, M B; Fukuda, S; Fukuda, Y; Ishihara, K; Itow, Y; Koshio, Y; Minamino, A; Miura, M; Moriyama, S; Nakahata, M; Namba, T; Nambu, R; Obayashi, Y; Sakurai, N; Shiozawa, M; Suzuki, Y; Takeuchi, H; Takeuchi, Y; Yamada, S; Ishitsuka, M; Kajita, T; Kaneyuki, K; Nakayama, S; Okada, A; Ooyabu, T; Saji, C; Desai, S; Earl, M; Kearns, E; Messier, M D; Stone, J L; Sulak, L R; Walter, C W; Wang, W; Goldhaber, M; Barszczak, T; Casper, D; Gajewski, W; Kropp, W R; Mine, S; Liu, D W; Sobel, H W; Vagins, M R; Gago, A; Ganezer, K S; Hill, J; Keig, W E; Kim, J Y; Lim, I T; Ellsworth, R W; Tasaka, S; Kibayashi, A; Learned, J G; Matsuno, S; Takemori, D; Hayato, Y; Ichikawa, A K; Ishii, T; Kameda, J; Kobayashi, T; Maruyama, T; Nakamura, K; Nitta, K; Oyama, Y; Sakuda, M; Totsuka, Y; Yoshida, M; Iwashita, T; Suzuki, A T; Inagaki, T; Kato, I; Nakaya, T; Nishikawa, K; Haines, T J; Dazeley, S; Hatakeyama, S; Svoboda, R; Blaufuss, E; Goodman, J A; Guillian, G; Sullivan, G W; Turcan, D; Scholberg, K; Habig, A; Ackermann, M; Jung, C K; Kato, T; Kobayashi, K; Martens, K; Malek, M; Mauger, C; McGrew, C; Sharkey, E; Viren, B; Yanagisawa, C; Toshito, T; Mitsuda, C; Miyano, K; Shibata, T; Kajiyama, Y; Nagashima, Y; Takita, M; Kim, H I; Kim, S B; Yoo, J; Okazawa, H; Ishizuka, T; Choi, Y; Seo, H K; Etoh, M; Gando, Y; Hasegawa, T; Inoue, K; Shirai, J; Suzuki, A; Koshiba, M; Hatakeyama, Y; Ichikawa, Y; Koike, M; Nishijima, K; Ishino, H; Morii, M; Nishimura, R; Watanabe, Y; Kielczewska, D; Zalipska, J; Berns, H G; Boyd, S C; Stachyra, A L; Wilkes, R J

    2004-01-01

    The time variation of the elastic scattering rate of solar neutrinos with electrons in Super-Kamiokande-I was fit to the variations expected from active two-neutrino oscillations. The best fit in the Large Mixing Angle solution has a mixing angle of tan^2theta=0.55 and a mass squared difference of Deltam^2=6.3times10^-5eV^2 between the two neutrino mass eigenstates. The fitted day/night asymmetry of -1.8+-1.6(stat)+1.3-1.2(syst)% has improved statistical precision over previous measurements and agrees well with the expected asymmetry of -2.1%.

  18. Solar models of low neutrino-counting rate - The depleted Maxwellian tail

    Science.gov (United States)

    Clayton, D. D.; Dwek, E.; Newman, M. J.; Talbot, R. J., Jr.

    1975-01-01

    Evolutionary sequences for the sun are presented which confirm that the Cl-37 neutrino counting rate will be greatly reduced if the high-energy tail of the Maxwellian distribution of relative energies is progressively depleted. Thermonuclear reaction rates and pressure are reevaluated for a distribution function modified by the correction factor suggested by Clayton (1974), and the effect of the results on solar models calculated with a simple Henyey code is discussed. It is shown that if the depletion is characterized by a certain exponential dependence on the distribution function, the counting rate will fall below 1 SNU for a distribution function of not less than 0.01. Suggestions are made for measuring the distribution function in the sun by means of neutrino spectroscopy and photography.

  19. LMA MSW solution of the solar neutrino problem and first KamLAND results

    CERN Document Server

    De Holanda, P C

    2003-01-01

    The first KamLAND results are in a very good agreement with the predictions made on the basis of the solar neutrino data and the LMA realization of the MSW mechanism. We perform a combined analysis of the KamLAND (rate, spectrum) and the solar neutrino data with a free boron neutrino flux f_B. The best fit values of neutrino parameters are Delta m^2 = 7.3e-5 eV^2, tg^2 theta = 0.41 and f_B = 1.05 with the 1 sigma intervals: Delta m^2 = (6.2 - 8.4)e-5 eV^2, tg^2 theta = 0.33 - 0.54. We find the 3 sigma upper bounds: Delta m^2 4e-5 eV^2. At 99% C.L. the KamLAND spectral result splits the LMA region into two parts with the preferred one at Delta m^2 < 1e-4 eV^2. The higher Delta m^2 region is accepted at about 2 sigma level. We show that effects of non-zero 13-mixing, sin^2 theta_{13} < 0.04, are small leading to slight improvement of the fit in higher Delta m^2 region. In the best fit point we predict for SNO: CC/NC = 0.33 +0.05-0.03 and A_{DN}(SNO) = 2.8+-0.8 % (68% C.L.), and A_{DN}(SNO) < 9 % at th...

  20. Results of ultra-low level 71ge counting for application in the Gallex-solar neutrino experiment at the Gran Sasso Underground Physics Laboratory

    Science.gov (United States)

    Hampel, W.; Heusser, G.; Huebner, M.; Kiko, J.; Kirsten, T.; Schneider, K.; Schlotz, R.

    1985-01-01

    It has been experimentally verified that the Ultra-Low-Level Counting System for the Gallex solar neutrino experiment is capable of measuring the expected solar up silon-flux to plus or minus 12% during two years of operation.

  1. A Search for Neutrinos from the Solar hep Reaction and the DiffuseSupernova Neutrino Background with the Sudbury Neutrino Observatory

    Energy Technology Data Exchange (ETDEWEB)

    Aharmim, B.; Ahmed, S.N.; Anthony, A.E.; Beier, E.W.; Bellerive,A.; Bergevin, M.; Biller, S.D.; Boulay, M.G.; Chan, Y.D.; Chen, M.; Chen,X.; Cleveland, B.T.; Cox, G.A.; Currat, C.A.; Dai, X.; Dalnoki-Veress,F.; Deng, H.; Detwiler, J.; DiMarco, M.; Doe, P.J.; Doucas, G.; Drouin,P.-L.; Duncan, F.A.; Dunford, M.; Dunmore, J.A.; Earle, E.D.; Evans,H.C.; Ewan, G.T.; Farine, J.; Fergani, H.; Fleurot, F.; Ford, R.J.; Formaggio, J.A.; Gagnon, N.; Goon, J.T.M.; Graham, K.; Guillian, E.; Hahn, R.L.; Hallin, A.L.; Hallman, E.D.; Harvey, P.J.; Hazama, R.; Heeger, K.M.; Heintzelman, W.J.; Heise, J.; Helmer, R.L.; Hemingway,R.J.; Henning, R.; Hime, A.; Howard, C.; Howe, M.A.; Huang, M.; Jagam,P.; Jelley, N.A.; Klein, J.R.; Kormos, L.L.; Kos, M.; Krueger, A.; Kraus,C.; Krauss, C.B.; Kutter, T.; Kyba, C.C.M.; Labranche, H.; Lange, R.; Law, J.Lawson.I.T.; Lesko, K.T.; Leslie, J.R.; Loach, J.C.; Luoma, S.; MacLellan, R.; Majerus, S.; Mak, H.B.; Maneira, J.; Marino, A.D.; Martin,R.; McCauley, N.; McDonald, A.B.; McGee, S.; Mifflin, C.; Miknaitis,K.K.S.; Miller, M.L.; Monreal, B.; Nickel, B.G.; Noble, A.J.; Norman,E.B.; Oblath, N.S.; Okada, C.E.; O' Keeffe, H.M.; Orebi Gann, G.D.; Oser,S.M.; Ott, R.; Peeters, S.J.M.; Poon, A.W.P.; Prior, G.; Rielage, K.; Robertson, B.C.; Robertson, R.G.H.; Rollin, E.; Schwendener, M.H.; Secrest, J.A.; Seibert, S.R.; Simard, O.; Sims, C.J.; Sinclair, D.; Skensved, P.; Stokstad, R.G.; Stonehill, L.C.; Tesic, G.; Tolich, N.; Tsui, T.; Van Berg, R.; Van de Water, R.G.; VanDevender, B.A.; Virtue,C.J.; Walker, T.J.; Wall, B.L.; Waller, D.; Wan Chan Tseung, H.; Wark,D.L.; Wendland, J.; West, N.; Wilkerson, J.F.; Wilson, J.R.; Wouters,J.M.; Wright, A.; Yeh, M.; Zhang, F.; Zuber, K.

    2006-08-01

    A search has been made for neutrinos from the hep reactionin the Sun and from the diffuse supernova neutrino background (DSNB)using data collected during the first operational phase of the SudburyNeutrino Observatory, with an exposure of 0.65 kilotonne-years. For thehep neutrino search, two events are observed in the effective electronenergy range of 14.3 MeVneutrino oscillations, an upperlimit of 2.3 x 104 cm-2s-1 at the 90 percent confidence level is inferredon the integral total flux of hep neutrinos. For DSNB neutrinos, noevents are observed in the effective electron energy range of 21 MeVneutrino energy range of 22.9 MeVneutrino flux and by two orders of magnitude on theprevious upper limit on the nu e component of the DSNB flux.

  2. Particle Detection in Superfluid Helium: R&D for Low Energy Solar Neutrinos

    Energy Technology Data Exchange (ETDEWEB)

    Lanou, Robert E., Jr.

    2006-03-31

    This report presents a summary of the results from R&D conducted as a feasibility study in the Department of Physics of Brown University for detection of low energy solar neutrinos utilizing a superfluid helium target. The report outlines the results in several areas: 1) development of experimental facilities, 2) energy deposition by electrons and alphas in superfluid helium, 3) development of wafer and metallic magnetic calorimeters, 4) background studies, 5) coded apertures and conceptual design, 6) Detection of single electrons and 7) a simulation of expected performance of a full scale device. Recommendations for possible future work are also presented. A bibliography of published papers and unpublished doctoral theses is included.

  3. Improvement of Test of Solar Neutrino Coherent Scattering with Torsion Pendulum

    Institute of Scientific and Technical Information of China (English)

    FENG Guo-Qiang; YANG Shan-Qing; TU Liang-Cheng; LUO Jun

    2006-01-01

    @@ A torsion pendulum containing two sapphire crystals and two lead rings is used to test Weber's theory of enhanced solar neutrino coherent scattering. Our experiment gives a null result for the diurnal force with a noise level of 3.8 ×10-14N, which is 526 times smaller than the predicted value of Weber's theory, and directly rules out Weber's theory and the experimental result. This experiment also reveals a test of the weak equivalence principle with η(Al2O3, Pb)= (0.8±3.1)×10-10 for masses falling toward the Sun.

  4. Discrete flavour symmetries for degenerate solar neutrino pair and their predictions

    CERN Document Server

    Joshipura, Anjan S

    2014-01-01

    Flavour symmetries appropriate for describing a neutrino spectrum with degenerate solar pair and a third massive or massless neutrino are discussed. We demand that the required residual symmetries of the leptonic mass matrices be subgroups of some discrete symmetry group $G_f$. $G_f$ can be a subgroup of SU(3) if the third neutrino is massive and we derive general results on the mixing angle predictions for various discrete subgroups of SU(3). The main results are: (a) All the SU(3) subgroups of type C fail in simultaneously giving correct $\\theta_{13}$ and $\\theta_{23}$. (b) All the groups of type D can predict a relation $\\cos^2\\theta_{13} \\sin^2\\theta_{23}=\\frac{1}{3}$ among the mixing angles which appears to be a good zeroth order approximation. Among these, various $\\Delta(6n^2)$ groups with $n\\geq 8$ can simultaneously lead also to $\\sin^2 \\theta_{13}$ in agreement with global fit at 3$\\sigma$. (c) The group $\\Sigma(168)\\cong PSL(2,7)$ predicts near to the best fit value for $\\theta_{13}$ and $\\theta_{2...

  5. Getting the most from the statistical analysis of solar neutrino oscillations

    CERN Document Server

    Fogli, G L; Marrone, A; Montanino, D; Palazzo, A

    2002-01-01

    (Abridged.) We present a thorough analysis of the current solar neutrino data, in the context of two-flavor active neutrino oscillations. We aim at performing an accurate and exhaustive statistical treatment of both the input and the output information. Concerning the input, we analyze 81 observables, including the Cl rate, the total Ga rate and its winter-summer difference, the 44 spectrum bins from SK and the 34 spectrum bins from SNO. We carefully evaluate and propagate the effects of 31 correlated systematic uncertainties, including 12 SSM input errors, the 8B neutrino energy spectrum uncertainty, as well as 11 and 7 systematics in SK and SNO, respectively. Concerning the output, we express the chi-squared analysis results in terms of ``pulls,'' embedding the single contributions to the total chi-squared. It is shown that the pull method, as compared to the (numerically equivalent) covariance matrix approach, is not only simpler and more advantageous, but also includes useful indications about the preferr...

  6. Geo-neutrinos

    CERN Document Server

    Bellini, G; Ludhova, L; Mantovani, F; McDonough, W F

    2013-01-01

    We review a new interdisciplinary field between Geology and Physics: the study of the Earth's geo-neutrino flux. We describe competing models for the composition of the Earth, present geological insights into the make up of the continental and oceanic crust, those parts of the Earth that concentrate Th and U, the heat producing elements, and provide details of the regional settings in the continents and oceans where operating and planned detectors are sited. Details are presented for the only two operating detectors that are capable of measuring the Earth's geo-neutrinos flux: Borexino and KamLAND; results achieved to date are presented, along with their impacts on geophysical and geochemical models of the Earth. Finally, future planned experiments are highlighted.

  7. Muons and Neutrinos 2007

    OpenAIRE

    Gaisser, Thomas K.

    2008-01-01

    This paper is the written version of the rapporteur talk on Section HE-2, muons and neutrinos, presented at the 30th International Cosmic Ray Conference, Merida, Yucatan, July 11, 2007. Topics include atmospheric muons and neutrinos, solar neutrinos and astrophysical neutrinos as well as calculations and instrumentation related to these topics.

  8. The solar neutrino problem after the first results from KamLAND

    Energy Technology Data Exchange (ETDEWEB)

    Bandyopadhyay, Abhijit; Choubey, Sandhya; Gandhi, Raj; Goswami, Srubabati; Roy, D.P

    2003-05-01

    The first results from the KamLAND experiment have provided confirmational evidence for the Large Mixing Angle (LMA) Mikheyev-Smirnov-Wolfenstein (MSW) solution to the solar neutrino problem. We do a global analysis of solar and the recently announced KamLAND data (both rate and spectrum) and investigate its effect on the allowed region in the {delta}m{sup 2}-tan{sup 2}{theta} plane. The best-fit from a combined analysis which uses the KamLAND rate plus global solar data comes at {delta}m{sup 2}=6.06x10{sup -5} eV{sup 2} and tan{sup 2}{theta}=0.42, very close to the global solar best-fit, leaving a large allowed region within the global solar LMA contour. The inclusion of the KamLAND spectral data in the global fit gives a best-fit {delta}m{sup 2}=7.17x10{sup -5} eV{sup 2} and tan{sup 2}{theta}=0.43 and constrains the allowed areas within LMA, leaving essentially two allowed zones. Maximal mixing though allowed by the KamLAND data alone is disfavored by the global solar data and remains disallowed at about 3{sigma}. The low {delta}m{sup 2} solution (LOW) is now ruled out at about 5{sigma} with respect to the LMA solution.

  9. Measurement of the nue and Total 8B Solar Neutrino Fluxes with theSudbury Neutrino Observatory Phase I Data Set

    Energy Technology Data Exchange (ETDEWEB)

    Aharmim, B.; Ahmad, Q.R.; Ahmed, S.N.; Allen, R.C.; Andersen,T.C.; Anglin, J.D.; Buehler, G.; Barton, J.C.; Beier, E.W.; Bercovitch,M.; Bergevin, M.; Bigu, J.; Biller, S.D.; Black, R.A.; Blevis, I.; Boardman, R.J.; Boger, J.; Bonvin, E.; Boulay, M.G.; Bowler, M.G.; Bowles, T.J.; Brice, S.J.; Browne, M.C.; Bullard, T.V.; Burritt, T.H.; Cameron, J.; Chan, Y.D.; Chen, H.H.; Chen, M.; Chen, X.; Cleveland, B.T.; Cowan, J.H.M.; Cowen, D.F.; Cox, G.A.; Currat, C.A.; Dai, X.; Dalnoki-Veress, F.; Davidson, W.F.; Deng, H.; DiMarco, M.; Doe, P.J.; Doucas, G.; Dragowsky, M.R.; Duba, C.A.; Duncan, F.A.; Dunford, M.; Dunmore, J.A.; Earle, E.D.; Elliott, S.R.; Evans, H.C.; Ewan, G.T.; Farine, J.; Fergani, H.; Ferraris, A.P.; Fleurot, F.; Ford, R.J.; Formaggio, J.A.; Fowler, M.M.; Frame, K.; Frank, E.D.; Frati, W.; Gagnon,N.; Germani, J.V.; Gil, S.; Goldschmidt, A.; Goon, J.T.M.; Graham, K.; Grant, D.R.; Guillian, E.; Hahn, R.L.; Hallin, A.L.; Hallman, E.D.; Hamer, A.S.; Hamian, A.A.; Handler, W.B.; Haq, R.U.; Hargrove, C.K.; Harvey, P.J.; Hazama, R.; Heeger, K.M.; Heintzelman, W.J.; Heise, J.; Helmer, R.L.; Henning, R.; Hepburn, J.D.; Heron, H.; Hewett, J.; Hime,A.; Howard, C.; Howe, M.A.; Huang, M.; Hykawy, J.G.; Isaac, M.C.P.; Jagam, P.; Jamieson, B.; Jelley, N.A.; Jillings, C.; Jonkmans, G.; Kazkaz, K.; Keener, P.T.; Kirch, K.; Klein, J.R.; Knox, A.B.; Komar,R.J.; Kormos, L.L.; Kos, M.; Kouzes, R.; Krueger, A.; Kraus, C.; Krauss,C.B.; Kutter, T.; Kyba, C.C.M.; Labranche, H.; Lange, R.; Law, J.; Lawson, I.T.; Lay, M.; Lee, H.W.; Lesko, K.T.; Leslie, J.R.; Levine, I.; Loach, J.C.; Locke, W.; Luoma, S.; Lyon, J.; MacLellan, R.; Majerus, S.; Mak, H.B.; Maneira, J.; Marino, A.D.; Martin, R.; McCauley, N.; McDonald,A.B.; McDonald, D.S.; McFarlane, K.; McGee, S.; McGregor, G.; MeijerDrees, R.; Mes, H.; Mifflin, C.; Miknaitis, K.K.S.; Miller, M.L.; Milton,G.; Moffat, B.A.; Monreal, B.; Moorhead, M.; Morrissette, B.; Nally,C.W.; Neubauer, M.S.; et al.

    2007-02-01

    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.

  10. Unified fit of solar and atmospheric neutrinos: towards the MNSP matrix; Ajustements globaux des resultats des experiences de neutrinos solaires et atmospheriques: vers la determination de la matrice de melange des neutrinos (dite MNSP)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-01-01

    Present solar and atmospheric neutrino give a strong indication that neutrinos oscillate between the three active species. This is the first step towards the determination of their mass. But we have also to determine the 3 x 3 neutrino mixing matrix (3 angles and one or several phases linked to CP violation), called MNSP (Maki-Nakagawa-Suzuki-Pontecorvo) and similar to the quark mixing matrix, called CKM (Cabibbo-Kobayashi-Maskawa). The purpose of the colloquium (one day) is to give an overview of the present situation and what progresses are expected in the forthcoming years. 3 guidelines: pedagogical approach, critical review of the experimental situation and of the different analyses, lookout to the future. (author)

  11. Solar neutrinos global analysis with day and night spectra from SNO

    CERN Document Server

    De Holanda, P C

    2002-01-01

    We perform global analysis of the solar neutrino data including the day and night spectra of events at SNO. In the context of two active neutrino mixing, the best fit of the data is provided by the LMA MSW solution with Delta m^2 = 6.2 10^{-5} eV^2, tan^2\\theta = 0.4, f_B = 1.06, where f_B is the boron neutrino flux in units of the corresponding flux in the Standard Solar Model (SSM). At 3 sigma level we find the following upper bounds: tan^2\\theta < 0.8 and Delta m^2 < 3.3 10^{-4} eV^2. From 1 sigma-interval we expect the day-night asymmetries of the charged current and electron scattering events to be: A_{DN}^{CC} = 4 +4-3 and A_{DN}^{ES} = 2.1 +1.9-1.6. The only other solution which appears at 3 sigma-level is the VAC solution with Delta m^2 = 4.5 10^{-10} eV^2, tan^2\\theta = 2.1 and f_B=0.72. The best fit point in the LOW region, with Delta m^2 = 0.93 10^{-7} eV^2 and tan^2\\theta = 0.68, is accepted at 99.86% (3.2 sigma) C.L. . The least chi^2 point from the SMA solution region, with Delta m^2 = 5 1...

  12. On the measurement of solar neutrino oscillation parameters with KamLAND

    Energy Technology Data Exchange (ETDEWEB)

    Bandyopadhyay, Abhijit; Choubey, Sandhya; Goswami, Srubabati; Petcov, S.T

    2004-02-12

    A new reactor power plant Shika-2, with a power of approximately 4 GW and at a distance of about 88 km from the KamLAND detector is scheduled to start operating in March 2006. We study the impact of the {nu}-bar{sub e} flux from this reactor on the sensitivity of the KamLAND experiment to the solar neutrino oscillation parameters. We present results on prospective determination of {delta}m{sup 2}{sub o} and sin{sup 2}{theta}{sub o} using the combined data from KamLAND and the solar neutrino experiments, including the effect of the Shika-2 contribution to the KamLAND signal and the latest data from the salt enriched phase of the SNO experiment. We find that contrary to the expectations, the addition of the Shika-2 reactor flux does not improve the sin{sup 2}{theta}{sub o} sensitivity of KamLAND, while the ambiguity in {delta}m{sup 2}{sub o} measurement may even increase, as a result of the averaging effect between Kashiwazaki and the Shika-2 reactor contributions to the KamLAND signal.

  13. The Story of the Neutrino

    CERN Document Server

    Rajasekaran, G

    2016-01-01

    This is an elementary review of the history and physics of neutrinos. The story of the discovery of neutrino mass through neutrino oscillations is described in some detail. Experiments on solar neutrinos and atmospheric neutrinos played an important part. Recent advances are summarized and future developments are indicated.

  14. Are there nu_mu or nu_tau in the flux of solar neutrinos on earth?

    CERN Document Server

    Giunti, C

    2002-01-01

    Using the model independent method of Villante, Fiorentini, Lisi, Fogli, Palazzo, and the rates measured in the SNO and Super-Kamiokande solar neutrino experiment, we calculate the amount of active nu_mu or nu_tau present in the flux of solar neutrinos on Earth. We show that the probability of nu_e->nu_{mu,tau} transitions is larger than zero at 99.89% CL. We find that the averaged flux of nu_{mu,tau} on Earth is larger than 0.17 times the 8B nu_e flux predicted by the BP2000 Standard Solar Model at 99% CL. We also derive a model-independent lower limit of 0.52 at 99% CL for the ratio of the 8B nu_e flux produced in the Sun and its value in the BP2000 Standard Solar Model.

  15. Shedding light on LMA-Dark solar neutrino solution by medium baseline reactor experiments: JUNO and RENO-50

    CERN Document Server

    Bakhti, Pouya

    2014-01-01

    In the presence of Non-Standard neutral current Interactions (NSI) a new solution to solar neutrino anomaly with $\\cos 2\\theta_{12}<0$ appears. We show that this solution can be tested by upcoming intermediate baseline reactor experiments JUNO and RENO-50.

  16. The chemical composition of the sun from helioseismic and solar neutrino data

    Energy Technology Data Exchange (ETDEWEB)

    Villante, Francesco L. [Dipartimento di Scienze Fisiche e Chimiche, Università dell' Aquila, I-67100 L' Aquila (Italy); Serenelli, Aldo M. [Instituto de Ciencias del Espacio (CSIC-IEEC), Facultad de Ciencias, E-08193 Bellaterra (Spain); Delahaye, Franck [LERMA, Observatoire de Paris, ENS, UPMC, UCP, CNRS, F-92190 Meudon (France); Pinsonneault, Marc H. [Astronomy Department, Ohio State University, Columbus, OH 43210 (United States)

    2014-05-20

    We perform a quantitative analysis of the solar composition problem by using a statistical approach that allows us to combine the information provided by helioseismic and solar neutrino data in an effective way. We include in our analysis the helioseismic determinations of the surface helium abundance and of the depth of the convective envelope, the measurements of the {sup 7}Be and {sup 8}B neutrino fluxes, and the sound speed profile inferred from helioseismic frequencies. We provide all the ingredients to describe how these quantities depend on the solar surface composition, different from the initial and internal composition due to the effects of diffusion and nuclear reactions, and to evaluate the (correlated) uncertainties in solar model predictions. We include error sources that are not traditionally considered such as those from inversion of helioseismic data. We, then, apply the proposed approach to infer the chemical composition of the Sun. Our result is that the opacity profile of the Sun is well constrained by the solar observational properties. In the context of a two-parameter analysis in which elements are grouped as volatiles (i.e., C, N, O, and Ne) and refractories (i.e., Mg, Si, S, and Fe), the optimal surface composition is found by increasing the abundance of volatiles by (45 ± 4)% and that of refractories by (19 ± 3)% with respect to the values provided by Asplund et al. (2009, ARA and A, 47, 481). This corresponds to the abundances ε{sub O} = 8.85 ± 0.01 and ε{sub Fe} = 7.52 ± 0.01, which are consistent at the ∼1σ level with those provided by Grevesse and Sauval (1998, SSRv, 85, 161). As an additional result of our analysis, we show that the best fit to the observational data is obtained with values of input parameters of the standard solar models (radiative opacities, gravitational settling rate, and the astrophysical factors S {sub 34} and S {sub 17}) that differ at the ∼1σ level from those presently adopted.

  17. Data integrity and electronic calibrations for the Neutral Current Detector phase measurement of the 8B solar neutrino flux at the Sudbury Neutrino Observatory

    Science.gov (United States)

    Cox-Mobrand, Gary A.

    The Sudbury Neutrino Observatory (SNO) is a heavy water Cherenkov detector that observed solar neutrinos via elastic-scattering, charge-current and neutral-current interactions. SNO was designed to measure the flux the total 8B solar neutrino flux in three separate phases, making each measurement under a different set of detector conditions and detection mechanisms. In the third phase, an array of 3He proportional counters was installed, called Neutral Current Detectors (NCDs), which detected neutrons liberated in the neutral-current interactions with deuterium. The neutrino flux can be measured in the NCD phase by identification of neutron capture events via pulse-shape analysis techniques. To accomplish this, the transformation of the neutron capture signals caused by the NCD electronics and data acquisition system (NCD DAQ) must be well known. The NCD DAQ electronics model was developed and quantified, resulting in a small contribution to the systematic uncertainties of neutron identification. Of the four currently proposed neutron identification methods, the parameters which characterize the logarithmic amplification of pulse shapes contribute 1.65%, 0.65%, 0.05% and 0.0% to the systematic uncertainty in the number of identified neutrons. A mechanical problem in two NCDs was discovered that caused the detectors to disconnect from the signal cable with little evidence of being disconnected. The work presented here identified two NCDs that suffered from this mechanical problem and estimated the amount of time that each NCD was disconnected. The remaining NCDs are shown to be unaffected by this problem and an upper limit on the amount of time disconnected was estimated. This was accomplished by an analysis of the rate of thermal noise triggers, an instrumental background noise event. The detected rates of background alphas were also measured to test for anomalously low rates. It was determined that these two NCDs should be removed from the final neutrino flux

  18. Low-energy neutrinos

    CERN Document Server

    Ludhova, Livia

    2016-01-01

    There exist several kinds of sources emitting neutrinos in the MeV energy range. These low-energy neutrinos from different sources can be often detected by the same multipurpose detectors. The status-of-art of the feld of solar neutrinos, geoneutrinos, and the search for sterile neutrino with artifcial neutrino sources is provided here; other neutrino sources, as for example reactor or high-energy neutrinos, are described elsewhere. For each of these three felds, the present-day motivation and open questions, as well as the latest experimental results and future perspectives are discussed.

  19. Neutrino Experiments and Their Implications

    OpenAIRE

    Balantekin, A. B.

    2004-01-01

    Recent developments in solar, reactor, and accelerator neutrino physics are reviewed. Implications for neutrino physics, solar physics, nuclear two-body physics, and r-process nucleosynthesis are briefly discussed.

  20. Noise reduction for proportional counter signals in the GNO solar neutrino experiment

    Energy Technology Data Exchange (ETDEWEB)

    Kiko, J. E-mail: kiko@mpi-hd.mpg.de

    2002-04-11

    The GALLEX solar neutrino experiment as well as the follow-up experiment GNO are low-level, low-statistics experiments with a mean production rate of 0.7 {sup 71}Ge atoms per day by neutrino capture on 30.3 t of natural gallium. This is a challenge with respect to the long time stability of the whole equipment, especially the stability of the electronic components which acquire the signals of the {sup 71}Ge decay events in proportional counters. Approximately, every month a sample of about ten {sup 71}Ge atoms (half-life 11.4 d) is typically measured in the GALLEX and GNO experiments for a period of half a year. The background is minimized by low-level techniques. In addition, {sup 71}Ge decays are distinguished from background events by pulse shape analyses. The background rejection efficiency is directly correlated with the signal to noise ratio of the recorded events. A method is described which increases the signal to noise ratio of the acquired ionization events and allows to distinguish between detector signals and noise picked up from the detector environment. This method can be applied not only for proportional counters but also for many other detectors.

  1. Noise reduction for proportional counter signals in the GNO solar neutrino experiment

    CERN Document Server

    Kiko, J

    2002-01-01

    The GALLEX solar neutrino experiment as well as the follow-up experiment GNO are low-level, low-statistics experiments with a mean production rate of 0.7 sup 7 sup 1 Ge atoms per day by neutrino capture on 30.3 t of natural gallium. This is a challenge with respect to the long time stability of the whole equipment, especially the stability of the electronic components which acquire the signals of the sup 7 sup 1 Ge decay events in proportional counters. Approximately, every month a sample of about ten sup 7 sup 1 Ge atoms (half-life 11.4 d) is typically measured in the GALLEX and GNO experiments for a period of half a year. The background is minimized by low-level techniques. In addition, sup 7 sup 1 Ge decays are distinguished from background events by pulse shape analyses. The background rejection efficiency is directly correlated with the signal to noise ratio of the recorded events. A method is described which increases the signal to noise ratio of the acquired ionization events and allows to distinguish ...

  2. Effects of sudden mixing in the solar core on solar neutrinos and ice ages.

    Science.gov (United States)

    Ezer, D.; Cameron, A. G. W.

    1972-01-01

    Some numerical experiments with a solar model have been conducted in connection with the hypothesis regarding the effects of mixing in the solar core. Questions concerning a plausible mechanism by which such a mixing could be produced are explored. The variation of solar luminosity throughout the numerical experiments is shown. In connection with a great change in luminosity after a second mixing, it is suggested that the earth is presently undergoing an ice age.

  3. InP solid state detector for measurement of low energy solar neutrinos

    Energy Technology Data Exchange (ETDEWEB)

    Fukuda, Yoshiyuki, E-mail: fukuda@staff.miyakyo-u.ac.j [Faculty of Education, Miyagi University of Education, 149, Aobaku-aza-aoba, Sendai, Miyagi 980-0845 (Japan); Izawa, Toshiyuki [Solid State Division, Hamamatsu Photonics K.K. 1126-1, Ichino-cho, Hamamatsu, Shizuoka 435-8558 (Japan); Koshio, Yusuke; Moriyama, Shigetaka [Kamioka Observatory, Institute for Cosmic Ray Research, University of Tokyo, Higashi-Mozumi, Kamioka-cho, Hida, Gifu 506-1205 (Japan); Namba, Toshio [ICEPP, International Center for Elementary Particle Physics, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033 (Japan); Shiozawa, Masato [Kamioka Observatory, Institute for Cosmic Ray Research, University of Tokyo, Higashi-Mozumi, Kamioka-cho, Hida, Gifu 506-1205 (Japan)

    2010-11-01

    A large volume radiation detector using a semi-insulating Indium Phosphide (InP) wafer has been developed for Indium Project on Neutrino Observation for Solar interior (IPNOS) experiment. We have achieved the volume of 20 mm{sup 3}, and this is world largest one among InP detectors which observed {gamma}'s at hundred keV region. In spite of the depletion layer, most of charge generated by electron hole pair production are collected by an induction, and the charge collection efficiency and the energy resolution are obtained by 60% and 25%, respectively. We measured actual backgrounds related to {sup 115}In {beta} decay, and no significant background was found.

  4. Research and development of a helium-4 based solar neutrino detector

    Energy Technology Data Exchange (ETDEWEB)

    Lanou, R.E.; Maris, H.J.; Seidel, G.M.

    1990-12-01

    We report on work accomplished in the first 30 months of a research and development program to investigate the feasibility of a new technique to detect solar neutrinos in superfluid helium. Accomplishments include the successful completion of design, construction and operation of the entire cryogenic, mechanical and electronic apparatus. During the last several months we have begun a series of experiments in superfluid helium to test the method. Experimental results include the first observation of the combined physical processes essential to the detection technique: ballistic roton generation by energetic charged particles, quantum evaporation of helium at a free surface and bolometric detection of the evaporated helium by physisorption on a cold silicon wafer. Additional results are also presented.

  5. Determination of the νe and total B8 solar neutrino fluxes using the Sudbury Neutrino Observatory Phase I data set

    Science.gov (United States)

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

    2007-04-01

    This article provides the complete description of results from the Phase I data set of the Sudbury Neutrino Observatory (SNO). The Phase I data set is based on a 0.65 kiloton-year exposure of 2H2O (in the following denoted as D2O) to the solar B8 neutrino flux. Included here are details of the SNO physics and detector model, evaluations of systematic uncertainties, and estimates of backgrounds. Also discussed are SNO's approach to statistical extraction of the signals from the three neutrino reactions (charged current, neutral current, and elastic scattering) and the results of a search for a day-night asymmetry in the νe flux. Under the assumption that the B8 spectrum is undistorted, the measurements from this phase yield a solar νe flux of ϕ(νe)=1.76-0.05+0.05(stat.)-0.09+0.09(syst.)×106 cm-2 s-1 and a non-νe component of ϕ(νμτ)=3.41-0.45+0.45(stat.)-0.45+0.48(syst.)×106 cm-2 s-1. The sum of these components provides a total flux in excellent agreement with the predictions of standard solar models. The day-night asymmetry in the νe flux is found to be Ae=7.0±4.9(stat.)-1.2+1.3%(syst.), when the asymmetry in the total flux is constrained to be zero.

  6. New Limits on Nucleon Decays into Invisible Channels with the BOREXINO Counting Test Facility

    CERN Document Server

    Back, H O; De Bari, A; Beau, T; De Bellefon, A; Bellini, G; Benziger, J B; Bonetti, S; Buck, C; Caccianiga, B; Cadonati, L; Calaprice, F P; Cecchet, G; Chen, M; Di Credico, A; Dadoun, O; D'Angelo, D; Denisov, V Yu; Derbin, A V; Deutsch, M; Elisei, F; Etenko, A; Von Feilitzsch, F; Fernholz, R; Ford, R; Franco, D; Freudiger, B; Galbiati, C; Gatti, F; Gazzana, S; Giammarchi, M G; Giugni, D; Goeger-Neff, M; Goretti, A; Grieb, C; Hanger, C; Heusser, G; Ianni, A; Ianni, A M; De Kerret, H; Kiko, J; Kirsten, T; Kobychev, V V; Korga, G; Korschinek, G; Kozlov, Y; Kryn, D; Laubenstein, M; Litvinovich, E; Lendvai, C; Lombardi, P; Machulin, I; Malvezzi, S; Maneira, J; Manno, I; Manuzio, D; Manuzio, G; Masetti, F; Martemyanov, A N; Mazzucato, U; McCarty, K; Meroni, E; Miramonti, L; Monzani, M E; Musico, P; Niedermeier, L; Oberauer, L; Obolensky, M; Ortica, F; Pallavicini, M; Papp, L; Perasso, L; Pocar, A; Ponkratenko, O A; Raghavan, R S; Ranucci, G; Razeto, A; Sabelnikov, A; Salvo, C; Scardaoni, R; Schimizzi, D; Schönert, S; Simgen, H; Shutt, T A; Skorokhvatov, M; Smirnov, O Yu; Sonnenschein, A; Sotnikov, A; Sukhotin, S; Tarasenkov, V; Tartaglia, R; Testeran, G; Tretyak, V I; Vignaud, D; Vogelaar, R B; Vyrodov, V N; Wójcik, M; Zaimidoroga, O A; Zdesenko, Yu G; Zuzel, G

    2003-01-01

    The results of background measurements with the second version of the BOREXINO Counting Test Facility (CTF-II), installed in the Gran Sasso Underground Laboratory, were used to obtain limits on the instability of nucleons, bounded in nuclei, for decays into invisible channels (inv): disappearance, decays to neutrinos, etc. The approach consisted of a search for decays of unstable nuclides resulting from N and NN decays of parent ^{12}C, ^{13}C and ^{16}C nuclei in the liquid scintillator and the water shield of the CTF. Due to the extremely low background and the large mass (4.2 ton) of the CTF detector, the most stringent (or competitive) up-to-date experimental bounds have been established: \\tau(n\\to inv)>1.8\\cdot 10^{25} y, \\tau(p\\to inv)>1.1\\cdot 10^{26} y, \\tau(nn\\to inv)>4.9\\cdot 10^{25} y and \\tau(pp\\to inv)>5.0\\cdot 10^{25}y (all at 90 % C. L.).

  7. New Limits for the Violation of the Equivalence Principle in the Solar-Reactor Neutrino Sector

    CERN Document Server

    Valdiviesso, G do A; De Holanda, P C

    2008-01-01

    A model for the violation of the equivalence principle (VEP) on solar and reactor neutrinos is investigated. New limits for the VEP are obtained considering the mass-flavor mixing hypothesis and the VEP model. Our analysis shows two solutions were the VEP effects practically don't change the solar sector. In a first case, the mass scale of the reactor sector remains the same and in a second situation this scale falls slightly, becoming closer to the solar solution without VEP. The combined solution points to the following set of parameters: a ``higher VEP'' $|\\phi\\Delta\\gamma|=9,12^{+0,97}_{-0,78}\\times10^{-21}$, $\\tan^2\\theta=0,478^{+0,040}_{-0,038}$ and $\\Delta m^2=6,63\\pm0,31\\times10^{-5} eV^2$ ($77,7%$ C.L.) and a ``lower VEP'' $|\\phi\\Delta\\gamma|=1,91^{+0,84}_{-0,61}\\times10^{-21}$, $\\tan^2\\theta=0,478^{+0,040}_{-0,038}$ e $\\Delta m^2=7,73^{+0,17}_{-0,20}\\times10^{-5} eV^2$ ($77,7%$ C.L.). Both solutions have increased confidence level when compared with the MSW solution ($\\tan^2\\theta=0,462^{+0,043}_{-0...

  8. On the study of neutrino properties

    OpenAIRE

    2005-01-01

    We review the discovery of the neutrino and outline the history of neutrino physics. Many interesting phenomena involving the neutrino are exhibited. We also discuss the long-standing solar neutrino puzzle and the properties of the neutrino which lead to various important results. We present a possible experimental test of the neutrino property. In addition, neutrino oscillation and neutrino spin precession are also demonstrated.

  9. Non-renormalizable operators for solar neutrino mass generation in Split SuSy with bilinear R-parity violation

    Science.gov (United States)

    Díaz, Marco Aurelio; Koch, Benjamin; Rojas, Nicolás

    2017-03-01

    The Minimal Supersymmetric Extension of the Standard Model (MSSM) is able to explain the current data from neutrino physics. Unfortunately Split Supersymmetry as low energy approximation of this theory fails to generate a solar square mass difference, including after the addition of bilinear R-Parity Violation. In this work, it is shown how one can derive an effective low energy theory from the MSSM in the spirit of Split Supersymmetry, which has the potential of explaining the neutrino phenomenology. This is achieved by going beyond leading order in the process of integrating out heavy scalars from the original theory, which results in non-renormalizable operators in the effective low energy theory. It is found that in particular a d = 8 operator is crucial for the generation of the neutrino mass differences.

  10. Neutrino Physics with JUNO

    CERN Document Server

    An, Fengpeng; An, Qi; Antonelli, Vito; Baussan, Eric; Beacom, John; Bezrukov, Leonid; Blyth, Simon; Brugnera, Riccardo; Avanzini, Margherita Buizza; Busto, Jose; Cabrera, Anatael; Cai, Hao; Cai, Xiao; Cammi, Antonio; Cao, Guofu; Cao, Jun; Chang, Yun; Chen, Shaomin; Chen, Shenjian; Chen, Yixue; Chiesa, Davide; Clemenza, Massimiliano; Clerbaux, Barbara; Conrad, Janet; D'Angelo, Davide; De Kerret, Herve; Deng, Zhi; Deng, Ziyan; Ding, Yayun; Djurcic, Zelimir; Dornic, Damien; Dracos, Marcos; Drapier, Olivier; Dusini, Stefano; Dye, Stephen; Enqvist, Timo; Fan, Donghua; Fang, Jian; Favart, Laurent; Ford, Richard; Goger-Neff, Marianne; Gan, Haonan; Garfagnini, Alberto; Giammarchi, Marco; Gonchar, Maxim; Gong, Guanghua; Gong, Hui; Gonin, Michel; Grassi, Marco; Grewing, Christian; Guan, Mengyun; Guarino, Vic; Guo, Gang; Guo, Wanlei; Guo, Xin-Heng; Hagner, Caren; Han, Ran; He, Miao; Heng, Yuekun; Hsiung, Yee; Hu, Jun; Hu, Shouyang; Hu, Tao; Huang, Hanxiong; Huang, Xingtao; Huo, Lei; Ioannisian, Ara; Jeitler, Manfred; Ji, Xiangdong; Jiang, Xiaoshan; Jollet, Cecile; Kang, Li; Karagounis, Michael; Kazarian, Narine; Krumshteyn, Zinovy; Kruth, Andre; Kuusiniemi, Pasi; Lachenmaier, Tobias; Leitner, Rupert; Li, Chao; Li, Jiaxing; Li, Weidong; Li, Weiguo; Li, Xiaomei; Li, Xiaonan; Li, Yi; Li, Yufeng; Li, Zhi-Bing; Liang, Hao; Lin, Guey-Lin; Lin, Tao; Lin, Yen-Hsun; Ling, Jiajie; Lippi, Ivano; Liu, Dawei; Liu, Hongbang; Liu, Hu; Liu, Jianglai; Liu, Jianli; Liu, Jinchang; Liu, Qian; Liu, Shubin; Liu, Shulin; Lombardi, Paolo; Long, Yongbing; Lu, Haoqi; Lu, Jiashu; Lu, Jingbin; Lu, Junguang; Lubsandorzhiev, Bayarto; Ludhova, Livia; Luo, Shu; Lyashuk, Vladimir; Mollenberg, Randolph; Ma, Xubo; Mantovani, Fabio; Mao, Yajun; Mari, Stefano M; McDonough, William F; Meng, Guang; Meregaglia, Anselmo; Meroni, Emanuela; Mezzetto, Mauro; Miramonti, Lino; Mueller, Thomas; Naumov, Dmitry; Oberauer, Lothar; Ochoa-Ricoux, Juan Pedro; Olshevskiy, Alexander; Ortica, Fausto; Paoloni, Alessandro; Peng, Haiping; Peng, Jen-Chieh; Previtali, Ezio; Qi, Ming; Qian, Sen; Qian, Xin; Qian, Yongzhong; Qin, Zhonghua; Raffelt, Georg; Ranucci, Gioacchino; Ricci, Barbara; Robens, Markus; Romani, Aldo; Ruan, Xiangdong; Ruan, Xichao; Salamanna, Giuseppe; Shaevitz, Mike; Sinev, Valery; Sirignano, Chiara; Sisti, Monica; Smirnov, Oleg; Soiron, Michael; Stahl, Achim; Stanco, Luca; Steinmann, Jochen; Sun, Xilei; Sun, Yongjie; Taichenachev, Dmitriy; Tang, Jian; Tkachev, Igor; Trzaska, Wladyslaw; van Waasen, Stefan; Volpe, Cristina; Vorobel, Vit; Votano, Lucia; Wang, Chung-Hsiang; Wang, Guoli; Wang, Hao; Wang, Meng; Wang, Ruiguang; Wang, Siguang; Wang, Wei; Wang, Yi; Wang, Yifang; Wang, Zhe; Wang, Zheng; Wang, Zhigang; Wang, Zhimin; Wei, Wei; Wen, Liangjian; Wiebusch, Christopher; Wonsak, Bjorn; Wu, Qun; Wulz, Claudia-Elisabeth; Wurm, Michael; Xi, Yufei; Xia, Dongmei; Xie, Yuguang; Xing, Zhi-zhong; Xu, Jilei; Yan, Baojun; Yang, Changgen; Yang, Chaowen; Yang, Guang; Yang, Lei; Yang, Yifan; Yao, Yu; Yegin, Ugur; Yermia, Frederic; You, Zhengyun; Yu, Boxiang; Yu, Chunxu; Yu, Zeyuan; Zavatarelli, Sandra; Zhan, Liang; Zhang, Chao; Zhang, Hong-Hao; Zhang, Jiawen; Zhang, Jingbo; Zhang, Qingmin; Zhang, Yu-Mei; Zhang, Zhenyu; Zhao, Zhenghua; Zheng, Yangheng; Zhong, Weili; Zhou, Guorong; Zhou, Jing; Zhou, Li; Zhou, Rong; Zhou, Shun; Zhou, Wenxiong; Zhou, Xiang; Zhou, Yeling; Zhou, Yufeng; Zou, Jiaheng

    2015-01-01

    The Jiangmen Underground Neutrino Observatory (JUNO), a 20 kton multi-purpose underground liquid scintillator detector, was proposed with the determination of the neutrino mass hierarchy as a primary physics goal. It is also capable of observing neutrinos from terrestrial and extra-terrestrial sources, including supernova burst neutrinos, diffuse supernova neutrino background, geoneutrinos, atmospheric neutrinos, solar neutrinos, as well as exotic searches such as nucleon decays, dark matter, sterile neutrinos, etc. We present the physics motivations and the anticipated performance of the JUNO detector for various proposed measurements. By detecting reactor antineutrinos from two power plants at 53-km distance, JUNO will determine the neutrino mass hierarchy at a 3-4 sigma significance with six years of running. The measurement of antineutrino spectrum will also lead to the precise determination of three out of the six oscillation parameters to an accuracy of better than 1\\%. Neutrino burst from a typical cor...

  11. The next-generation liquid-scintillator neutrino observatory LENA

    CERN Document Server

    Wurm, Michael; Bezrukov, Leonid B; Bick, Daniel; Blümer, Johannes; Choubey, Sandhya; Ciemniak, Christian; D'Angelo, Davide; Dasgupta, Basudeb; Dighe, Amol; Domogatsky, Grigorij; Dye, Steve; Eliseev, Sergey; Enqvist, Timo; Erykalov, Alexey; von Feilitzsch, Franz; Fiorentini, Gianni; Fischer, Tobias; Göger-Neff, Marianne; Grabmayr, Peter; Hagner, Caren; Hellgartner, Dominikus; Hissa, Johannes; Horiuchi, Shunsaku; Janka, Hans-Thomas; Jaupart, Claude; Jochum, Josef; Kalliokoski, Tuomo; Kuusiniemi, Pasi; Lachenmaier, Tobias; Lazanu, Ionel; Learned, John G; Lewke, Timo; Lombardi, Paolo; Lorenz, Sebastian; Lubsandorzhiev, Bayarto; Ludhova, Livia; Loo, Kai; Maalampi, Jukka; Mantovani, Fabio; Marafini, Michela; Maricic, Jelena; Undagoitia, Teresa Marrodán; McDonough, William F; Miramonti, Lino; Mirizzi, Alessandro; Meindl, Quirin; Mena, Olga; Möllenberg, Randolph; Nahnhauer, Rolf; Nesterenko, Dmitry; Novikov, Yuri N; Nuijten, Guido; Oberauer, Lothar; Pakvasa, Sandip; Palomares-Ruiz, Sergio; Pallavicini, Marco; Pascoli, Silvia; Patzak, Thomas; Peltoniemi, Juha; Potzel, Walter; Räihä, Tomi; Raffelt, Georg G; Ranucci, Gioacchino; Razzaque, Soebur; Rummukainen, Kari; Sarkamo, Juho; Sinev, Valerij; Spiering, Christian; Stahl, Achim; Thorne, Felicitas; Tippmann, Marc; Tonazzo, Alessandra; Trzaska, Wladyslaw H; Vergados, John D; Wiebusch, Christopher; Winter, Jürgen

    2011-01-01

    We propose the liquid-scintillator detector LENA (Low Energy Neutrino Astronomy) as a next-generation neutrino observatory on the scale of 50 kt. The outstanding successes of the Borexino and KamLAND experiments demonstrate the large potential of liquid-scintillator detectors in low-energy neutrino physics. LENA's physics objectives comprise the observation of astrophysical and terrestrial neutrino sources as well as the investigation of neutrino oscillations. In the GeV energy range, the search for proton decay and long-baseline neutrino oscillation experiments complement the low-energy program. Based on the considerable expertise present in European and international research groups, the technical design is sufficiently mature to allow for an early start of detector realization.

  12. Neutrino Magnetic Moment

    OpenAIRE

    Balantekin, A. B.

    2006-01-01

    Current experimental and observational limits on the neutrino magnetic moment are reviewed. Implications of the recent results from the solar and reactor neutrino experiments for the value of the neutrino magnetic moment are discussed. It is shown that spin-flavor precession in the Sun is suppressed.

  13. Neutrino Observations from the Sudbury Neutrino Observatory

    Science.gov (United States)

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

    2001-09-24

    The Sudbury Neutrino Observatory (SNO) is a water imaging Cherenkov detector. Its usage of 1000 metric tons of D{sub 2}O as target allows the SNO detector to make a solar-model independent test of the neutrino oscillation hypothesis by simultaneously measuring the solar {nu}{sub e} flux and the total flux of all active neutrino species. Solar neutrinos from the decay of {sup 8}B have been detected at SNO by the charged-current (CC) interaction on the deuteron and by the elastic scattering (ES) of electrons. While the CC reaction is sensitive exclusively to {nu}{sub e}, the ES reaction also has a small sensitivity to {nu}{sub {mu}} and {nu}{sub {tau}}. In this paper, recent solar neutrino results from the SNO experiment are presented. It is demonstrated that the solar flux from {sup 8}B decay as measured from the ES reaction rate under the no-oscillation assumption is consistent with the high precision ES measurement by the Super-Kamiokande experiment. The {nu}{sub e} flux deduced from the CC reaction rate in SNO differs from the Super-Kamiokande ES results by 3.3{sigma}. This is evidence for an active neutrino component, in additional to {nu}{sub e}, in the solar neutrino flux. These results also allow the first experimental determination of the total active {sup 8}B neutrino flux from the Sun, and is found to be in good agreement with solar model predictions.

  14. Neutrino observations from the Sudbury Neutrino Observatory

    Energy Technology Data Exchange (ETDEWEB)

    Ahmad, Q.R.; Allen, R.C.; Andersen, T.C.; Anglin, J.D.; Barton,J.C.; Beier, E.W.; Bercovitch, M.; Bigu, J.; Biller, S.D.; Black, R.A.; Blevis, I.; Boardman, R.J.; Boger, J.; Bonvin, E.; Boulay, M.G.; Bowler,M.G.; Bowles, T.J.; Brice, S.J.; Browne, M.C.; Bullard, T.V.; Buhler, G.; Cameron, J.; Chan, Y.D.; Chen, H.H.; Chen, M.; Chen, X.; Cleveland, B.T.; Clifford, E.T.H.; Cowan, J.H.M.; Cowen, D.F.; Cox, G.A.; Dai, X.; Dalnoki-Veress, F.; Davidson, W.F.; Doe, P.J.; Doucas, G.; Dragowsky,M.R.; Duba, C.A.; Duncan, F.A.; Dunford, M.; Dunmore, J.A.; Earle, E.D.; Elliott, S.R.; Evans, H.C.; Ewan, G.T.; Farine, J.; Fergani, H.; Ferraris, A.P.; Ford, R.J.; Formaggio, J.A.; Fowler, M.M.; Frame, K.; Frank, E.D.; Frati, W.; Gagnon, N.; Germani, J.V.; Gil, S.; Graham, K.; Grant, D.R.; Hahn, R.L.; Hallin, A.L.; Hallman, E.D.; Hamer, A.S.; Hamian, A.A.; Handler, W.B.; Haq, R.U.; Hargrove, C.K.; Harvey, P.J.; Hazama, R.; Heeger, K.M.; Heintzelman, W.J.; Heise, J.; Helmer, R.L.; Hepburn, J.D.; Heron, H.; Hewett, J.; Hime, A.; Hykawy, J.G.; Isaac,M.C.P.; Jagam, P.; Jelley, N.A.; Jillings, C.; Jonkmans, G.; Kazkaz, K.; Keener, P.T.; Klein, J.R.; Knox, A.B.; Komar, R.J.; Kouzes, R.; Kutter,T.; Kyba, C.C.M.; Law, J.; Lawson, I.T.; Lay, M.; Lee, H.W.; Lesko, K.T.; Leslie, J.R.; Levine, I.; Locke, W.; Luoma, S.; Lyon, J.; Majerus, S.; Mak, H.B.; Maneira, J.; Manor, J.; Marino, A.D.; McCauley, N.; McDonald,D.S.; McDonald, A.B.; McFarlane, K.; McGregor, G.; Meijer, R.; Mifflin,C.; Miller, G.G.; Milton, G.; Moffat, B.A.; Moorhead, M.; Nally, C.W.; Neubauer, M.S.; Newcomer, F.M.; Ng, H.S.; Noble, A.J.; Norman, E.B.; Novikov, V.M.; O' Neill, M.; Okada, C.E.; Ollerhead, R.W.; Omori, M.; Orrell, J.L.; Oser, S.M.; Poon, A.W.P.; Radcliffe, T.J.; Roberge, A.; Robertson, B.C.; Robertson, R.G.H.; Rosendahl, S.S.E.; Rowley, J.K.; Rusu, V.L.; Saettler, E.; Schaffer, K.K.; Schwendener,M.H.; Schulke, A.; Seifert, H.; Shatkay, M.; Simpson, J.J.; Sims, C.J.; et al.

    2001-09-24

    The Sudbury Neutrino Observatory (SNO) is a water imaging Cherenkov detector. Its usage of 1000 metric tons of D{sub 2}O as target allows the SNO detector to make a solar-model independent test of the neutrino oscillation hypothesis by simultaneously measuring the solar {nu}{sub e} flux and the total flux of all active neutrino species. Solar neutrinos from the decay of {sup 8}B have been detected at SNO by the charged-current (CC) interaction on the deuteron and by the elastic scattering (ES) of electrons. While the CC reaction is sensitive exclusively to {nu}{sub e}, the ES reaction also has a small sensitivity to {nu}{sub {mu}} and {nu}{sub {tau}}. In this paper, recent solar neutrino results from the SNO experiment are presented. It is demonstrated that the solar flux from {sup 8}B decay as measured from the ES reaction rate under the no-oscillation assumption is consistent with the high precision ES measurement by the Super-Kamiokande experiment. The {nu}{sub e} flux deduced from the CC reaction rate in SNO differs from the Super-Kamiokande ES results by 3.3{sigma}. This is evidence for an active neutrino component, in additional to {nu}{sub e}, in the solar neutrino flux. These results also allow the first experimental determination of the total active {sup 8}B neutrino flux from the Sun, and is found to be in good agreement with solar model predictions.

  15. Brief Neutrino Physics Update

    CERN Document Server

    Valle, José W F

    2003-01-01

    The discovery of neutrino mass establishes the need for physics beyond the Standard Model. I summarize the status of two- and three-neutrino oscillation parameters from current solar, atmospheric, reactor and accelerator data. Future neutrinoless double beta decay experiments will probe the nature of neutrinos, as well as the absolute scale of neutrino mass, also tested by tritium beta decay spectra and cosmological observations. Sterile neutrinos do not provide a good way to account for the LSND hint, which needs further confirmation. Finally I sketch the main theoretical ideas for generating neutrino mass.

  16. The Sudbury Neutrino Observatory

    CERN Document Server

    Boger, J; Rowley, J K; Carter, A L; Hollebone, B; Kessler, D; Blevis, I; Dalnoki-Veress, F; De Kok, A; Farine, J; Grant, D R; Hargrove, C K; Laberge, G; Levine, I; McFarlane, K W; Mes, H; Noble, A T; Novikov, V M; O'Neill, M; Shatkay, M; Shewchuk, C; Sinclair, D; Clifford, E T H; Deal, R; Earle, E D; Gaudette, E; Milton, G; Sur, B; Bigu, J; Cowan, J H M; Cluff, D L; Hallman, E D; Haq, R U; Hewett, J L; Hykawy, J G; Jonkmans, G; Michaud, R; Roberge, A; Roberts, J; Saettler, E; Schwendener, M H; Seifert, H; Sweezey, D; Tafirout, R; Virtue, C J; Beck, D N; Chan, Y D; Chen, X; Dragowsky, M R; Dycus, F W; González, J; Isaac, M C P; Kajiyama, Y; Köhler, G W; Lesko, K T; Moebus, M C; Norman, E B; Okada, C E; Poon, A W P; Purgalis, P; Schülke, A; Smith, A R; Stokstad, R G; Turner, S; Zlimen, I; Anaya, J M; Bowles, T J; Brice, S J; Esch, E I; Fowler, M M; Goldschmidt, A; Hime, A; McGirt, A F; Miller, G G; Teasdale, W A; Wilhelmy, J B; Wouters, J M; Anglin, J D; Bercovitch, M; Davidson, W F; Storey, R S; Biller, S; Black, R A; Boardman, R J; Bowler, M G; Cameron, J; Cleveland, B; Ferraris, A P; Doucas, G; Heron, H; Howard, C; Jelley, N A; Knox, A B; Lay, M; Locke, W; Lyon, J; Majerus, S; Moorhead, M E; Omori, Mamoru; Tanner, N W; Taplin, R K; Thorman, M; Wark, D L; West, N; Barton, J C; Trent, P T; Kouzes, R; Lowry, M M; Bell, A L; Bonvin, E; Boulay, M; Dayon, M; Duncan, F; Erhardt, L S; Evans, H C; Ewan, G T; Ford, R; Hallin, A; Hamer, A; Hart, P M; Harvey, P J; Haslip, D; Hearns, C A W; Heaton, R; Hepburn, J D; Jillings, C J; Korpach, E P; Lee, H W; Leslie, J R; Liu, M Q; Mak, H B; McDonald, A B; MacArthur, J D; McLatchie, W; Moffat, B A; Noel, S; Radcliffe, T J; Robertson, B C; Skensved, P; Stevenson, R L; Zhu, X; Gil, S; Heise, J; Helmer, R L; Komar, R J; Nally, C W; Ng, H S; Waltham, C E; Allen, R C; Buhler, G; Chen, H H; Aardsma, G; Andersen, T; Cameron, K; Chon, M C; Hanson, R H; Jagam, P; Karn, J; Law, J; Ollerhead, R W; Simpson, J J; Tagg, N; Wang, J X; Alexander, C; Beier, E W; Cook, J C; Cowen, D F; Frank, E D; Frati, W; Keener, P T; Klein, J R; Mayers, G; McDonald, D S; Neubauer, M S; Newcomer, F M; Pearce, R J; Van de Water, R G; Van Berg, R; Wittich, P; Ahmad, Q R; Beck, J M; Browne, M C; Burritt, T H; Doe, P J; Duba, C A; Elliott, S R; Franklin, J E; Germani, J V; Green, P; Hamian, A A; Heeger, K M; Howe, M; Meijer-Drees, R; Myers, A; Robertson, R G H; Smith, M W E; Steiger, T D; Van Wechel, T; Wilkerson, J F

    2000-01-01

    The Sudbury Neutrino Observatory is a second generation water Cherenkov detector designed to determine whether the currently observed solar neutrino deficit is a result of neutrino oscillations. The detector is unique in its use of D2O as a detection medium, permitting it to make a solar model-independent test of the neutrino oscillation hypothesis by comparison of the charged- and neutral-current interaction rates. In this paper the physical properties, construction, and preliminary operation of the Sudbury Neutrino Observatory are described. Data and predicted operating parameters are provided whenever possible.

  17. The Sudbury Neutrino Observatory

    Energy Technology Data Exchange (ETDEWEB)

    Boger, J.; Hahn, R.L.; Rowley, J.K.; Carter, A.L.; Hollebone, B.; Kessler, D.; Blevis, I.; Dalnoki-Veress, F.; DeKok, A.; Farine, J.; Grant, D.R.; Hargrove, C.K.; Laberge, G.; Levine, I.; McFarlane, K.; Mes, H.; Noble, A.T.; Novikov, V.M.; O' Neill, M.; Shatkay, M.; Shewchuk, C.; Sinclair, D.; Clifford, E.T.H.; Deal, R.; Earle, E.D.; Gaudette, E.; Milton, G.; Sur, B.; Bigu, J.; Cowan, J.H.M.; Cluff, D.L.; Hallman, E.D.; Haq, R.U.; Hewett, J.; Hykawy, J.G.; Jonkmans, G.; Michaud, R.; Roberge, A.; Roberts, J.; Saettler, E.; Schwendener, M.H.; Seifert, H.; Sweezey, D.; Tafirout, R.; Virtue, C.J.; Beck, D.N.; Chan, Y.D.; Chen, X.; Dragowsky, M.R.; Dycus, F.W.; Gonzalez, J.; Isaac, M.C.P.; Kajiyama, Y.; Koehler, G.W.; Lesko, K.T.; Moebus, M.C.; Norman, E.B.; Okada, C.E.; Poon, A.W.P.; Purgalis, P.; Schuelke, A.; Smith, A.R.; Stokstad, R.G.; Turner, S.; Zlimen, I.; Anaya, J.M.; Bowles, T.J.; Brice, S.J.; Esch, Ernst-Ingo; Fowler, M.M.; Goldschmidt, Azriel; Hime, A.; McGirt, A.F.; Miller, G.G.; Teasdale, W.A.; Wilhelmy, J.B.; Wouters, J.M.; Anglin, J.D.; Bercovitch, M.; Davidson, W.F.; Storey, R.S.; Biller, S.; Black, R.A.; Boardman, R.J.; Bowler, M.G.; Cameron, J.; Cleveland, B.; Ferraris, A.P.; Doucas, G.; Heron, H.; Howard, C.; Jelley, N.A. E-mail: N.Jelley1@physics.ox.ac.uk; Knox, A.B.; Lay, M.; Locke, W.; Lyon, J.; Majerus, S.; Moorhead, M.; Omori, M.; Tanner, N.W.; Taplin, R.K.; Thorman, M.; Wark, D.L.; West, N.; Barton, J.C.; Trent, P.T.; Kouzes, R.; Lowry, M.M.; Bell, A.L.; Bonvin, E.; Boulay, M.; Dayon, M.; Duncan, F.; Erhardt, L.S.; Evans, H.C.; Ewan, G.T.; Ford, R.; Hallin, A.; Hamer, A.; Hart, P.M.; Harvey, P.J.; Haslip, D.; Hearns, C.A.W.; Heaton, R.; Hepburn, J.D.; Jillings, C.J.; Korpach, E.P.; Lee, H.W.; Leslie, J.R.; Liu, M.-Q.; Mak, H.B.; McDonald, A.B.; MacArthur, J.D.; McLatchie, W.; Moffat, B.A.; Noel, S.; Radcliffe, T.J.; Robertson, B.C.; Skensved, P.; Stevenson, R.L.; Zhu, X.; Gil, S.; Heise, J.; Helmer, R.L.; Komar, R.J.; Nally, C.W. [and others

    2000-07-11

    The Sudbury Neutrino Observatory is a second-generation water Cherenkov detector designed to determine whether the currently observed solar neutrino deficit is a result of neutrino oscillations. The detector is unique in its use of D{sub 2}O as a detection medium, permitting it to make a solar model-independent test of the neutrino oscillation hypothesis by comparison of the charged- and neutral-current interaction rates. In this paper the physical properties, construction, and preliminary operation of the Sudbury Neutrino Observatory are described. Data and predicted operating parameters are provided whenever possible.

  18. Neutrino Oscillation Studies with Reactors

    CERN Document Server

    Vogel, Petr; Zhang, Chao

    2015-01-01

    Nuclear reactors are one of the most intense, pure, controllable, cost-effective, and well-understood sources of neutrinos. Reactors have played a major role in the study of neutrino oscillations, a phenomenon that indicates that neutrinos have mass and that neutrino flavors are quantum mechanical mixtures. Over the past several decades reactors were used in the discovery of neutrinos, were crucial in solving the solar neutrino puzzle, and allowed the determination of the smallest mixing angle $\\theta_{13}$. In the near future, reactors will help to determine the neutrino mass hierarchy and to solve the puzzling issue of sterile neutrinos.

  19. The physics of neutrinos

    CERN Document Server

    Barger, Vernon D; Whisnant, Kerry

    2012-01-01

    The physics of neutrinos- uncharged elementary particles that are key to helping us better understand the nature of our universe - is one of the most exciting frontiers of modern science. This book provides a comprehensive overview of neutrino physics today and explores promising new avenues of inquiry that could lead to future breakthroughs. The Physics of Neutrinos begins with a concise history of the field and a tutorial on the fundamental properties of neutrinos, and goes on to discuss how the three neutrino types interchange identities as they propagate from their sources to detectors. The book shows how studies of neutrinos produced by such phenomena as cosmic rays in the atmosphere and nuclear reactions in the solar interior provide striking evidence that neutrinos have mass, and it traces our astounding progress in deciphering the baffling experimental findings involving neutrinos. The discovery of neutrino mass offers the first indication of a new kind of physics that goes beyond the Standard Model ...

  20. Neutrino Sources and Properties

    CERN Document Server

    Vissani, Francesco

    2014-01-01

    In this lecture, prepared for PhD students, basic considerations on neutrino interactions, properties and sites of production are overviewed. The detailed content is as follows: Sect. 1, Weak interactions and neutrinos: Fermi coupling; definition of neutrinos; global numbers. Sect. 2, A list of neutrino sources: Explanatory note and examples (solar pp- and supernova-neutrinos). Sect. 3, Neutrinos oscillations: Basic formalism (Pontecorvo); matter effect (Mikheev, Smirnov, Wolfenstein); status of neutrino masses and mixings. Sect. 4, Modifying the standard model to include neutrinos masses: The fermions of the standard model; one additional operator in the standard model (Weinberg); implications. One summary table and several exercises offer the students occasions to check, consolidate and extend their understanding; the brief reference list includes historical and review papers and some entry points to active research in neutrino physics.

  1. Neutrinos Mass and Mixing

    CERN Document Server

    González-Garciá, M Concepción

    1998-01-01

    I review the status of neutrino masses and mixings in the light of the solar and atmospheric neutrino data. The result from the LSND experiment and the possible role of neutrinos as hot dark matter are also included. I also discuss the simplest schemes proposed to reconcile these data which include a light sterile neutrino in addition to the three standard ones. Implications for future experiments are commented.

  2. Four-Neutrino Oscillations at SNO

    CERN Document Server

    González-Garciá, M Concepción

    2001-01-01

    We discuss the potential of the Sudbury Neutrino Observatory (SNO) to constraint the four-neutrino mixing schemes favoured by the results of all neutrino oscillations experiments. These schemes allow simultaneous transitions of solar $\

  3. Solar neutrino: Flux, cosmic rays and the 11 year solar cycle

    Science.gov (United States)

    Raychaudhuri, P.

    1985-01-01

    It is shown that the results of maximum likelihood treatment of Monte Carlo simulation with constant production rate of 7.6 SNU and 1.Epsilon SNU are consistent with the constant production rate when the tests of hypotheses (e.g., t-test, sigma squared-test, Wilcoxon-Mann-Whitney test, run test, etc.) are applied to the two groups of data formed from sunspot minimum range and sunspot maximum range, whereas the real data pulsates with the solar activity cycle. It is shown that SN flux-change is in opposition phase to the solar activity cycle and lags behind the latter by about one year. A correlation between SN flux and the cosmic rays is suggested.

  4. Design Constraints for a WIMP Dark Matter and pp Solar Neutrino Liquid Neon Scintillation Detector

    CERN Document Server

    Boulay, M G; Lidgard, J

    2004-01-01

    Detailed Monte-Carlo simulations were used to evaluate the performance of a liquid neon scintillation detector for dark matter and low-energy solar neutrino interactions. A maximum-likelihood event vertex fitter including PMT time information was developed, which significantly improves position resolution over spatial-only algorithms, and substantially decreases the required detector size and achievable analysis energy threshold. The ultimate sensitivity to WIMP dark matter and the pp flux uncertainty are evaluated as a function of detector size. The dependence on the neon scintillation and PMT properties are evaluated. A 300 cm radius detector would allow a ~13 keV threshold, a pp flux uncertainty of ~1%, and limits on the spin-independent WIMP-nucleon cross-section of ~10^{-46} cm^2 for a 100 GeV WIMP, using commercially available PMTs. Detector response calibration and background requirements for a precision pp measurement are defined. Internal radioactivity requirements for uranium, thorium, and krypton a...

  5. Global analyses of neutrino oscillation experiments

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez-Garcia, M.C., E-mail: maria.gonzalez-garcia@stonybrook.edu [Institució Catalana de Recerca i Estudis Avançats (ICREA), Departament d' Estructura i Constituents de la Matèria and Institut de Ciencies del Cosmos, Universitat de Barcelona, Diagonal 647, E-08028 Barcelona (Spain); C.N. Yang Institute for Theoretical Physics, State University of New York at Stony Brook, Stony Brook, NY 11794-3840 (United States); Maltoni, Michele, E-mail: michele.maltoni@csic.es [Instituto de Física Teórica UAM/CSIC, Calle de Nicolás Cabrera 13–15, Universidad Autónoma de Madrid, Cantoblanco, E-28049 Madrid (Spain); Schwetz, Thomas, E-mail: schwetz@kit.edu [Institut für Kernphysik, Karlsruher Institut für Technologie (KIT), D-76021 Karlsruhe (Germany)

    2016-07-15

    We summarize the determination of some neutrino properties from the global analysis of solar, atmospheric, reactor, and accelerator neutrino data in the framework of three-neutrino mixing as well as in some extended scenarios such as the mixing with eV-scale sterile neutrinos invoked for the interpretation of the short baseline anomalies, and the presence of non-standard neutrino interactions.

  6. Global Analyses of Neutrino Oscillation Experiments

    CERN Document Server

    Gonzalez-Garcia, M C; Schwetz, Thomas

    2015-01-01

    We summarize the determination of some neutrino properties from the global analysis of solar, atmospheric, reactor, and accelerator neutrino data in the framework of three-neutrino mixing as well as in some extended scenarios such as the mixing with eV-scale sterile neutrinos invoked for the interpretation of the short baseline anomalies, and the presence of non-standard neutrino interactions.

  7. Global analyses of neutrino oscillation experiments

    Science.gov (United States)

    Gonzalez-Garcia, M. C.; Maltoni, Michele; Schwetz, Thomas

    2016-07-01

    We summarize the determination of some neutrino properties from the global analysis of solar, atmospheric, reactor, and accelerator neutrino data in the framework of three-neutrino mixing as well as in some extended scenarios such as the mixing with eV-scale sterile neutrinos invoked for the interpretation of the short baseline anomalies, and the presence of non-standard neutrino interactions.

  8. Neutrinos: recent developments and origin of neutrino mass matrix

    CERN Document Server

    Riazuddin

    2004-01-01

    Certainly one of the most exciting areas of research at present is neutrino physics. The neutrinos are fantastically numerous in the universe and as such they have bearing on our understanding of the universe. Therefore, we must understand the neutrinos, particularly their mass. There is compelling evidence from solar and atmospheric neutrinos and those from reactors for neutrino oscillations implying that neutrinos mix and have nonzero mass but without pinning down their absolute mass. This is reviewed. The implications of neutrino oscillations and mass squared splitting between neutrinos of different flavor on pattern of neutrino mass matrix is discussed. In particular, a neutrino mass matrix, which shows approximate flavor symmetry where the neutrino mass differences arise from flavor violation in off-diagonal Yukawa couplings is elaborated on. The implications in double beta decay are also discussed.

  9. The Deficit of Solar Neutrinos and the Non-Standard Solar Models%太阳中微子"亏缺"与非标准太阳模型

    Institute of Scientific and Technical Information of China (English)

    林元章

    2000-01-01

    The background for the deficit of solar neutrinos, including the standard solar models, the nuclear fusions in solar interior, the theoretical estimations for the energy spectrum and flux of solar neutrinos, as well as the solar neutrino experiments and their results, are introduced in the first two sections of the paper. Then various non-standard solar models proposed to explain the deficit of solar neutrinos are described. Finally, the recent reports on the neutrino ocillation are briefly disussed.%系统阐述了太阳中微子"亏缺"问题出现的背景,包括介绍标准太阳模型,太阳内部的核聚变反应,太阳中微子能谱和流量的理论估算,以及太阳中微子探测实验和结果。讨论了为解释太阳中微子"亏缺"而提出的各种非标准太阳模型以及近年来愈益受到重视的中微子振动问题。

  10. Measurements of the atmospheric neutrino flux by Super-Kamiokande: Energy spectra, geomagnetic effects, and solar modulation

    Science.gov (United States)

    Richard, E.; Okumura, K.; Abe, K.; Haga, Y.; Hayato, Y.; Ikeda, M.; Iyogi, K.; Kameda, J.; Kishimoto, Y.; Miura, M.; Moriyama, S.; Nakahata, M.; Nakajima, T.; Nakano, Y.; Nakayama, S.; Orii, A.; Sekiya, H.; Shiozawa, M.; Takeda, A.; Tanaka, H.; Tomura, T.; Wendell, R. A.; Akutsu, R.; Irvine, T.; Kajita, T.; Kaneyuki, K.; Nishimura, Y.; Labarga, L.; Fernandez, P.; Gustafson, J.; Kachulis, C.; Kearns, E.; Raaf, J. L.; Stone, J. L.; Sulak, L. R.; Berkman, S.; Nantais, C. M.; Tanaka, H. A.; Tobayama, S.; Goldhaber, M.; Kropp, W. R.; Mine, S.; Weatherly, P.; Smy, M. B.; Sobel, H. W.; Takhistov, V.; Ganezer, K. S.; Hartfiel, B. L.; Hill, J.; Hong, N.; Kim, J. Y.; Lim, I. T.; Park, R. G.; Himmel, A.; Li, Z.; O'Sullivan, E.; Scholberg, K.; Walter, C. W.; Wongjirad, T.; Ishizuka, T.; Tasaka, S.; Jang, J. S.; Learned, J. G.; Matsuno, S.; Smith, S. N.; Friend, M.; Hasegawa, T.; Ishida, T.; Ishii, T.; Kobayashi, T.; Nakadaira, T.; Nakamura, K.; Oyama, Y.; Sakashita, K.; Sekiguchi, T.; Tsukamoto, T.; Suzuki, A. T.; Takeuchi, Y.; Yano, T.; Cao, S. V.; Hiraki, T.; Hirota, S.; Huang, K.; Kikawa, T.; Minamino, A.; Nakaya, T.; Suzuki, K.; Fukuda, Y.; Choi, K.; Itow, Y.; Suzuki, T.; Mijakowski, P.; Frankiewicz, K.; Hignight, J.; Imber, J.; Jung, C. K.; Li, X.; Palomino, J. L.; Wilking, M. J.; Yanagisawa, C.; Fukuda, D.; Ishino, H.; Kayano, T.; Kibayashi, A.; Koshio, Y.; Mori, T.; Sakuda, M.; Xu, C.; Kuno, Y.; Tacik, R.; Kim, S. B.; Okazawa, H.; Choi, Y.; Nishijima, K.; Koshiba, M.; Totsuka, Y.; Suda, Y.; Yokoyama, M.; Bronner, C.; Hartz, M.; Martens, K.; Marti, Ll.; Suzuki, Y.; Vagins, M. R.; Martin, J. F.; Konaka, A.; Chen, S.; Zhang, Y.; Wilkes, R. J.; Super-Kamiokande Collaboration

    2016-09-01

    A comprehensive study of the atmospheric neutrino flux in the energy region from sub-GeV up to several TeV using the Super-Kamiokande (SK) water Cherenkov detector is presented in this paper. The energy and azimuthal spectra, and variation over time, of the atmospheric νe+ν¯ e and νμ+ν¯μ fluxes are measured. The energy spectra are obtained using an iterative unfolding method by combining various event topologies with differing energy responses. The azimuthal spectra depending on energy and zenith angle, and their modulation by geomagnetic effects, are also studied. A predicted east-west asymmetry is observed in both the νe and νμ samples at 8.0 σ and 6.0 σ significance, respectively, and an indication that the asymmetry dipole angle changes depending on the zenith angle was seen at the 2.2 σ level. The measured energy and azimuthal spectra are consistent with the current flux models within the estimated systematic uncertainties. A study of the long-term correlation between the atmospheric neutrino flux and the solar magnetic activity cycle is performed, and a weak preference for a correlation was seen at the 1.1 σ level, using SK-I-SK-IV data spanning a 20-year period. For several particularly strong solar activity periods, corresponding to Forbush decrease events, no theoretical prediction is available but a deviation below the typical neutrino event rate is seen at the 2.4 σ level. The seasonal modulation of the neutrino flux is also examined, but the change in flux at the SK site is predicted to be negligible, and, as expected, no evidence for a seasonal correlation is seen.

  11. Development and validation of HELLAZ1 detector, contribution to the project HELLAZ concerning the detection of solar neutrinos; Developpement et mise au point du detecteur HELLAZ1: elaboration du projet HELLAZ pour la detection des neutrinos solaires

    Energy Technology Data Exchange (ETDEWEB)

    Gagliardi, N

    2001-09-01

    The HELLAZ project is dedicated to the measurement of low energy solar neutrinos, this neutrino detection is based on the measurement of the characteristics of all the ionization electrons produced by the recoil of the electron with which the solar neutrino has collided. The detector is made of a tank full of gaseous helium whose conditions of temperature and pressure (77 K and 5 bar) are important to assure a sufficient statistic. 11 events a day are expected to be detected. In this work we present the preliminary results obtained on the first prototype (HELLAZ0) that has allowed us to test 2 types of chambers: multiwire proportional chamber (MWPC) and a micro gas chamber combined to a gas electron multiplier (MGC+GEM). A new prototype (HELLAZ1) has been designed, its aim is to measure an elementary track of only 2 ionization electrons and to test 2 new chambers: micro gas wire chamber (MGWC) and Micromegas. The first chapter deals with the sun, solar neutrinos, and the neutrino characteristics that are expected from the sun standard model. The second chapter is dedicated to the various experiments of solar neutrino detection and to their experimental result disagreement. The HELLAZ project is described in the third chapter. The fourth chapter presents the different experimental constraints, particularly the processing of the background noise and the counting of each electron of the ionization cloud. In the last chapter HELLAZ0 and HELLAZ1 projects are described and we show that microstructure-type chambers are the best suitable for this kind of detection. (A.C.)

  12. The Sudbury Neutrino Observatory

    Science.gov (United States)

    Bellerive, A.; Klein, J. R.; McDonald, A. B.; Noble, A. J.; Poon, A. W. P.

    2016-07-01

    This review paper provides a summary of the published results of the Sudbury Neutrino Observatory (SNO) experiment that was carried out by an international scientific collaboration with data collected during the period from 1999 to 2006. By using heavy water as a detection medium, the SNO experiment demonstrated clearly that solar electron neutrinos from 8B decay in the solar core change into other active neutrino flavors in transit to Earth. The reaction on deuterium that has equal sensitivity to all active neutrino flavors also provides a very accurate measure of the initial solar flux for comparison with solar models. This review summarizes the results from three phases of solar neutrino detection as well as other physics results obtained from analyses of the SNO data.

  13. The Sudbury Neutrino Observatory

    CERN Document Server

    Bellerive, A; McDonald, A B; Noble, A J; Poon, A W P

    2016-01-01

    This review paper provides a summary of the published results of the Sudbury Neutrino Observatory (SNO) experiment that was carried out by an international scientific collaboration with data collected during the period from 1999 to 2006. By using heavy water as a detection medium, the SNO experiment demonstrated clearly that solar electron neutrinos from $^8$B decay in the solar core change into other active neutrino flavors in transit to Earth. The reaction on deuterium that has equal sensitivity to all active neutrino flavors also provides a very accurate measure of the initial solar flux for comparison with solar models. This review summarizes the results from three phases of solar neutrino detection as well as other physics results obtained from analyses of the SNO data.

  14. Neutrino anomaly and -nucleus interactions

    Indian Academy of Sciences (India)

    S K Singh

    2001-08-01

    A review of various calculations of the inclusive quasi-elastic reactions and pion production processes in neutrino reactions for various nuclei at intermediate energies relevant to solar, atmospheric and accelerator neutrinos is presented.

  15. First observation of beryllium-7 solar neutrinos with KamLAND

    Science.gov (United States)

    Keefer, Gregory J.

    2009-09-01

    The international KamLAND collaboration operates a 1 kton liquid scintillation detector in the Kamioka mine in Gifu, Japan. KamLAND's main scientific results are the precision measurement of the solar Dm 2 12 = 7.58[Special characters omitted.] (stat) [Special characters omitted.] (syst) and tan 2 [straight theta] 12 = 0.56[Special characters omitted.] (stat) [Special characters omitted.] (syst) utilizing reactor n e and first evidence for the observation of geologically produced anti-neutrinos. In an effort to extend KamLAND's scientific reach, extensive research has been performed on preparing a spectroscopic measurement of 7 Be solar n e s. This work provides the first inclusive analysis of KamLAND's backgrounds below 1 MeV. 85 Kr and 210 Pb, dissolved in KamLAND liquid scintillator, were found to be the dominant source of low energy backgrounds. The concentration of these ultra-trace contaminants were determined to be 10 -20 g/g. This is more than 6 orders of magnitude lower than commercially available ultra-pure liquids. To attain a signal-to-background ratio suitable for the detection of 7 Be solar n e s, the concentration of these contaminants had to be reduced by 5 orders of magnitude. A comprehensive study of 210 Pb removal was undertaken over the course of this thesis. This work further covers techniques for the removal of 220 Rn, 222 Rn and their daughter nuclei from liquid scintillator at concentrations of 10^-18 g/g. Purification techniques studied in this work include water extraction, isotope exchange, adsorption, and distillation. These laboratory studies guided the design and implementation of a large scale purification system in the Kamioka mine. The purification system's design and operation is discussed in detail as well as specific experiments devised to control scintillator quality and radio-purity. The purification system's effectiveness in removing radioactive trace impurities is analyzed in detail. The total scintillator purified over two

  16. Long-Baseline Neutrino Experiments

    Science.gov (United States)

    Diwan, M. V.; Galymov, V.; Qian, X.; Rubbia, A.

    2016-10-01

    We review long-baseline neutrino experiments in which neutrinos are detected after traversing macroscopic distances. Over such distances neutrinos have been found to oscillate among flavor states. Experiments with solar, atmospheric, reactor, and accelerator neutrinos have resulted in a coherent picture of neutrino masses and mixing of the three known flavor states. We summarize the current best knowledge of neutrino parameters and phenomenology, with a focus on the evolution of the experimental technique. We proceed from the first evidence produced by astrophysical neutrino sources to the current open questions and the goals of future research.

  17. Long-Baseline Neutrino Experiments

    CERN Document Server

    Diwan, M V; Qian, X; Rubbia, A

    2016-01-01

    We review long-baseline neutrino experiments in which neutrinos are detected after traversing macroscopic distances. Over such distances neutrinos have been found to oscillate among flavor states. Experiments with solar, atmospheric, reactor, and accelerator neutrinos have resulted in a coherent picture of neutrino masses and mixing of the three known flavor states. We will summarize the current best knowledge of neutrino parameters and phenomenology with our focus on the evolution of the experimental technique. We proceed from the first evidence produced by astrophysical neutrino sources to the current open questions and the goals of future research.

  18. Solar r-process-constrained actinide production in neutrino-driven winds of supernovae

    Science.gov (United States)

    Goriely, S.; Janka, H.-Th.

    2016-07-01

    Long-lived radioactive nuclei play an important role as nucleo-cosmochronometers and as cosmic tracers of nucleosynthetic source activity. In particular, nuclei in the actinide region like thorium, uranium, and plutonium can testify to the enrichment of an environment by the still enigmatic astrophysical sources that are responsible for the production of neutron-rich nuclei by the rapid neutron-capture process (r-process). Supernovae and merging neutron-star (NS) or NS-black hole binaries are considered as most likely sources of the r-nuclei. But arguments in favour of one or the other or both are indirect and make use of assumptions; they are based on theoretical models with remaining simplifications and shortcomings. An unambiguous observational determination of a production event is still missing. In order to facilitate searches in this direction, e.g. by looking for radioactive tracers in stellar envelopes, the interstellar medium or terrestrial reservoirs, we provide improved theoretical estimates and corresponding uncertainty ranges for the actinide production (232Th, 235, 236, 238U, 237Np, 244Pu, and 247Cm) in neutrino-driven winds of core-collapse supernovae. Since state-of-the-art supernova models do not yield r-process viable conditions - but still lack, for example, the effects of strong magnetic fields - we base our investigation on a simple analytical, Newtonian, adiabatic and steady-state wind model and consider the superposition of a large number of contributing components, whose nucleosynthesis-relevant parameters (mass weight, entropy, expansion time-scale, and neutron excess) are constrained by the assumption that the integrated wind nucleosynthesis closely reproduces the Solar system distribution of r-process elements. We also test the influence of uncertain nuclear physics.

  19. Neutrinos and their flavor mixing in nuclear astrophysics

    CERN Document Server

    Choubey, S

    2001-01-01

    In this thesis we explore the implications of neutrino oscillations in the context of the solar neutrino data, the atmospheric neutrino data and results from the terrestrial accelerator/reactor neutrino oscillation experiments. We perform comprehensive $\\chi^2$ analysis for the global solar neutrino data including SNO and present our results for two flavor $\

  20. On the status of neutrino mixing and oscillations

    OpenAIRE

    2002-01-01

    Evidences in favor of neutrino oscillations, obtained in the solar and atmospheric neutrino experiments, are discussed. Neutrino oscillations in the solar and atmospheric ranges of the neutrino mass-squared differences are considered in the framework of the minimal scheme with the mixing of three massive neutrinos.

  1. Los Alamos Science, Number 25 -- 1997: Celebrating the neutrino

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, N.G. [ed.

    1997-12-31

    This issue is devoted to the neutrino and its remaining mysteries. It is divided into the following areas: (1) The Reines-Cowan experiment -- detecting the poltergeist; (2) The oscillating neutrino -- an introduction to neutrino masses and mixing; (3) A brief history of neutrino experiments at LAMPF; (4) A thousand eyes -- the story of LSND (Los Alamos neutrino oscillation experiment); (5) The evidence for oscillations; (6) The nature of neutrinos in muon decay and physics beyond the Standard Model; (7) Exorcising ghosts -- in pursuit of the missing solar neutrinos; (8) MSW -- a possible solution to the solar neutrino problem; (8) Neutrinos and supernovae; and (9) Dark matter and massive neutrinos.

  2. Be7 solar neutrino measurement with KamLAND

    Energy Technology Data Exchange (ETDEWEB)

    Gando, A.; Gando, Y.; Hanakago, H.; Ikeda, H.; Inoue, K.; Ishidoshiro, K.; Ishikawa, H.; Kishimoto, Y.; Koga, M.; Matsuda, R.; Matsuda, S.; Mitsui, T.; Motoki, D.; Nakajima, K.; Nakamura, K.; Obata, A.; Oki, A.; Oki, Y.; Otani, M.; Shimizu, I.; Shirai, J.; Suzuki, A.; Tamae, K.; Ueshima, K.; Watanabe, H.; Xu, B. D.; Yamada, S.; Yamauchi, Y.; Yoshida, H.; Kozlov, A.; Takemoto, Y.; Yoshida, S.; Grant, C.; Keefer, G.; McKee, D. W.; Piepke, A.; Banks, T. I.; Bloxham, T.; Freedman, S. J.; Fujikawa, B. K.; Han, K.; Hsu, L.; Ichimura, K.; Murayama, H.; O' Donnell, T.; Steiner, H. M.; Winslow, L. A.; Dwyer, D.; Mauger, C.; McKeown, R. D.; Zhang, C.; Berger, B. E.; Lane, C. E.; Maricic, J.; Miletic, T.; Learned, J. G.; Sakai, M.; Horton-Smith, G. A.; Tang, A.; Downum, K. E.; Tolich, K.; Efremenko, Y.; Kamyshkov, Y.; Perevozchikov, O.; Karwowski, H. J.; Markoff, D. M.; Tornow, W.; Detwiler, J. A.; Enomoto, S.; Heeger, K.; Decowski, M. P.

    2015-11-30

    We report a measurement of the neutrino-electron elastic scattering rate of 862 keV 7Be solar neutrinos based on a 165.4 kt d exposure of KamLAND. The observed rate is 582±94(kt d)₋1, which corresponds to an 862-keV 7Be solar neutrino flux of (3.26±0.52)×109cm₋2s₋1, assuming a pure electron-flavor flux. Comparing this flux with the standard solar model prediction and further assuming three-flavor mixing, a νe survival probability of 0.66±0.15 is determined from the KamLAND data. Lastly, utilizing a global three-flavor oscillation analysis, we obtain a total 7Be solar neutrino flux of (5.82±1.02)×109cm₋2s₋1, which is consistent with the standard solar model predictions.

  3. Parametric resonance in neutrino oscillations in matter

    Indian Academy of Sciences (India)

    E Kh Akhmedov

    2000-01-01

    Neutrino oscillations in matter can exhibit a specific resonance enhancement - parametric resonance, which is different from the MSW resonance. Oscillations of atmospheric and solar neutrinos inside the earth can undergo parametric enhancement when neutrino trajectories cross the core of the earth. In this paper we review the parametric resonance of neutrino oscillations in matter. In particular, physical interpretation of the effect and the prospects of its experimental observation in oscillations of solar and atmospheric neutrinos in the earth are discussed.

  4. Naturally light sterile neutrinos

    CERN Document Server

    Sarkar, U

    1999-01-01

    A simple model to accomodate light sterile neutrinos naturally with large mixing with the usual neutrinos has been proposed. The standard model gauge group is extended to include an $SU(2)_S$ gauge symmetry. Heavy triplet higgs scalars give small masses to the left-handed neutrinos, while a heavy doublet higgs scalar give mixing with the sterile neutrinos of the same order of magnitude. The neutrino mass matrix thus obtained can explain the solar neutrino deficit, the atmospheric neutrino deficit, the LSND data and hot dark matter. Lepton number is violated here through decays of the heavy triplet higgs, which generates the lepton asymmetry of the universe, which in turn generates a baryon asymmetry of the universe.

  5. Indirect neutrino oscillations

    CERN Document Server

    Babu, K S; Wilczek, Frank; Pati, Jogesh C; Wilczek, Frank

    1995-01-01

    We show how two different scales for oscillations between e and \\mu neutrinos, characterized by different mixing angles and effective mass scales, can arise in a simple and theoretically attractive framework. One scale characterizes direct oscillations, which can accommodate the MSW approach to the solar neutrino problem, whereas the other can be considered as arising indirectly, through virtual transitions involving the \\tau neutrino with a mass \\sim 1 eV. This indirect transition allows the possibility of observable \\bar \

  6. Three Neutrino Flavors are Enough

    CERN Document Server

    Acker, A

    1996-01-01

    It is shown that it is possible to account for all three experimental indications for neutrino oscillations with just three neutrino flavors. In particular, we suggest that the solar and atmospheric neutrino anomalies are to be explained by the same mass difference and mixing. Possible implications and future tests of the resulting mass-mixing pattern are given.

  7. Neutrino masses From fantasy to facts

    CERN Document Server

    Valle, José W F

    1999-01-01

    Theory suggests the existence of neutrino masses, but little more. Facts are coming close to reveal our fantasy: solar and atmospheric neutrino data strongly indicate the need for neutrino conversions, while LSND provides an intriguing hint. The simplest ways to reconcile these data in terms of neutrino oscillations invoke a light sterile neutrino in addition to the three active ones. Out of the four neutrinos, two are maximally-mixed and lie at the LSND scale, while the others are at the solar mass scale. These schemes can be distinguished at neutral-current-sensitive solar & atmospheric neutrino experiments. I discuss the simplest theoretical scenarios, where the lightness of the sterile neutrino, the nearly maximal atmospheric neutrino mixing, and the generation of $\\Delta {m^2}_\\odot$ & $\\Delta {m^2}_{atm}$ all follow naturally from the assumed lepton-number symmetry and its breaking. Although the most likely interpretation of the present data is in terms of neutrino-mass-induced oscillations, one...

  8. Neutrino Masses, where do we stand?

    CERN Document Server

    Valle, José W F

    1999-01-01

    I review the status of neutrino physics post-Neutrino~98, including the implications of solar and atmospheric neutrino data, which strongly indicate nonzero neutrino masses. LSND and the possible role of neutrinos as hot dark matter (HDM) are also mentioned. The simplest schemes proposed to reconcile these requirements invoke a light sterile neutrino in addition to the three active ones, two of them at the MSW scale and the other two maximally-mixed neutrinos at the HDM/LSND scale. In the simplest theory the latter scale arises at one-loop, while the solar and atmospheric parameters $\\Delta {m^2}_\\odot$ & neutrino, the nearly maximal atmospheric neutrino mixing, and the generation of lepton-number symmetry and its breaking. These two basic schemes can be distinguished at future solar & atmospheric neutrino experiments and have different cosmological implications.

  9. Jiangmen Underground Neutrino Observatory: Status and Prospectives

    CERN Document Server

    Li, Yu-Feng

    2016-01-01

    The Jiangmen Underground Neutrino Observatory (JUNO) is a 20 kton liquid scintillator (LS) detector, which is planed to determine the neutrino mass hierarchy and measure the oscillation parameters at the sub-percent level using reactor antineutrino oscillations. As a multipurpose neutrino experiment, JUNO is also capable of measuring supernova burst neutrinos, the diffuse supernova neutrino background, geo-neutrinos, solar neutrinos and atmospheric neutrinos. After a brief introduction to the physics motivation, we discuss the status of the JUNO project, including the design of the detector systems. Finally the latest civil progress and future prospectives are also highlighted.

  10. Detection of low energy solar neutrinos by a two-phase cryogenic e-bubble detector

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A new two-phase cryogenic neutrino detector using electron bubble (e-bubble) specifically in liquid helium is proposed and being developed for real time, high rate measurements of low-energy p-p reaction neutrinos from the sun. The e-bubble detector is a time projection chamber-like (TPC) tracking detector. The task of such a neutrino detector is to detect the ionization of the elastically scattered target electrons by incident neutrinos, and then to characterize their energy and direction and to distinguish them from radioactive backgrounds. The ionization signals are expected to be small and hence undergo avalanche amplification in the saturated vapor above the liquid phase by gas electron multipliers (GEMs) at high gain. Higher granularity and intrinsically suppressed ion feedback give a good spatial resolution and are the major advantages of this technology. It should be possible to construct such a detector to track charged particles down to 100―200 keV in a massive liquid helium target with fractional millimeter spatial resolution in three-dimensional space, using the GEM-based TPC with a high-resolution CCD camera, for both the electronic and light readout.

  11. JUNO: a General Purpose Experiment for Neutrino Physics

    CERN Document Server

    Grassi, Marco

    2016-01-01

    JUNO is a 20 kt Liquid Scintillator Antineutrino Detector currently under construction in the south of China. This report reviews JUNO's physics programme related to all neutrino sources but reactor antineutrinos, namely neutrinos from supernova burst, solar neutrinos and geoneutrinos.

  12. Phenomenology of neutrino oscillations

    Indian Academy of Sciences (India)

    G Rajasekaran

    2000-07-01

    The phenomenology of solar, atmospheric, supernova and laboratory neutrino oscillations is described. Analytical formulae for matter effects are reviewed. The results from oscillations are confronted with neutrinoless double beta decay.

  13. Probing new limits for the Violation of the Equivalence Principle in the solar-reactor neutrino sector as a next to leading order effect

    Science.gov (United States)

    Valdiviesso, G. A.; Guzzo, M. M.; Holanda, P. C.

    2011-07-01

    New limits for the Violation of the Equivalence Principle (VEP) are obtained considering the mass-flavor mixing hypothesis. This analysis includes observations of solar and reactor neutrinos and has obtained a limit for the VEP parameter | Δγ | contributing to the νe and νbare disappearance channels of the order | Δγ | <10-14, when it is assumed that neutrinos are mainly affected by the gravitational potential ϕ ≈10-5 due to the Great Attractor.

  14. Probing new limits for the Violation of the Equivalence Principle in the solar-reactor neutrino sector as a next to leading order effect

    Energy Technology Data Exchange (ETDEWEB)

    Valdiviesso, G.A., E-mail: gustavo.valdiviesso@unifal-mg.edu.br [Instituto de Ciencia e Tecnologia, Universidade Federal de Alfenas, Unifal-mg, Rod. Jose Aurelio Vilela, 11999, 37715-400 Pocos de Caldas MG (Brazil); Instituto de Fisica Gleb Wataghin, Universidade Estadual de Campinas, UNICAMP, Rua Sergio Buarque de Holanda, 777, 13083-859 Campinas SP (Brazil); Guzzo, M.M., E-mail: guzzo@ifi.unicamp.br [Instituto de Fisica Gleb Wataghin, Universidade Estadual de Campinas, UNICAMP, Rua Sergio Buarque de Holanda, 777, 13083-859 Campinas SP (Brazil); Holanda, P.C., E-mail: holanda@ifi.unicamp.br [Instituto de Fisica Gleb Wataghin, Universidade Estadual de Campinas, UNICAMP, Rua Sergio Buarque de Holanda, 777, 13083-859 Campinas SP (Brazil)

    2011-07-04

    New limits for the Violation of the Equivalence Principle (VEP) are obtained considering the mass-flavor mixing hypothesis. This analysis includes observations of solar and reactor neutrinos and has obtained a limit for the VEP parameter |{Delta}{gamma}| contributing to the {nu}{sub e} and {nu}-bar{sub e} disappearance channels of the order |{Delta}{gamma}|<10{sup -14}, when it is assumed that neutrinos are mainly affected by the gravitational potential {phi}{approx}10{sup -5} due to the Great Attractor.

  15. On a Generalized Entropy Measure Leading to the Pathway Model with a Preliminary Application to Solar Neutrino Data

    Directory of Open Access Journals (Sweden)

    Hans J. Haubold

    2013-09-01

    Full Text Available An entropy for the scalar variable case, parallel to Havrda-Charvat entropy, was introduced by the first author, and the properties and its connection to Tsallis non-extensive statistical mechanics and the Mathai pathway model were examined by the authors in previous papers. In the current paper, we extend the entropy to cover the scalar case, multivariable case, and matrix variate case. Then, this measure is optimized under different types of restrictions, and a number of models in the multivariable case and matrix variable case are obtained. Connections of these models to problems in statistical and physical sciences are pointed out. An application of the simplest case of the pathway model to the interpretation of solar neutrino data by applying standard deviation analysis and diffusion entropy analysis is provided.

  16. Atmospheric Neutrinos

    Directory of Open Access Journals (Sweden)

    Takaaki Kajita

    2012-01-01

    Full Text Available Atmospheric neutrinos are produced as decay products in hadronic showers resulting from collisions of cosmic rays with nuclei in the atmosphere. Electron-neutrinos and muon-neutrinos are produced mainly by the decay chain of charged pions to muons to electrons. Atmospheric neutrino experiments observed zenith angle and energy-dependent deficit of muon-neutrino events. It was found that neutrino oscillations between muon-neutrinos and tau-neutrinos explain these data well. This paper discusses atmospheric neutrino experiments and the neutrino oscillation studies with these neutrinos.

  17. Progress in neutrino oscillation searches and their implications

    Indian Academy of Sciences (India)

    Srubabati Goswami

    2003-02-01

    Neutrino oscillation, in which a given flavor of neutrino transforms into another is a powerful tool for probing small neutrino masses. The intrinsic neutrino properties involved are neutrino mass squared difference 2 and the mixing angle in vacuum . In this paper I will summarize the progress that we have achieved in our search for neutrino oscillation with special emphasis on the recent results from the Sudbury Neutrino Observatory (SNO) on the measurement of solar neutrino fluxes. I will outline the current bounds on the neutrino masses and mixing parameters and discuss the major physics goals of future neutrino experiments in the context of the present picture.

  18. Atmospheric Neutrinos

    OpenAIRE

    Takaaki Kajita

    1994-01-01

    Atmospheric neutrinos are produced as decay products in hadronic showers resulting from collisions of cosmic rays with nuclei in the atmosphere. Electron-neutrinos and muon-neutrinos are produced mainly by the decay chain of charged pions to muons to electrons. Atmospheric neutrino experiments observed zenith angle and energy-dependent deficit of muon-neutrino events. It was found that neutrino oscillations between muon-neutrinos and tau-neutrinos explain these data well. This paper discusses...

  19. A Search for Astrophysical Burst Signals at the Sudbury Neutrino Observatory

    CERN Document Server

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

    2013-01-01

    The Sudbury Neutrino Observatory (SNO) has confirmed the standard solar model and neutrino oscillations through the observation of neutrinos from the solar core. In this paper we present a search for neutrinos associated with sources other than the solar core, such as gamma-ray bursters and solar flares. We present a new method for looking for temporal coincidences between neutrino events and astrophysical bursts of widely varying intensity. No correlations were found between neutrinos detected in SNO and such astrophysical sources.

  20. Low-energy neutrino observation at Super-Kamiokande-III

    Energy Technology Data Exchange (ETDEWEB)

    Takeuchi, Y [Kamioka Observatory, ICRR, University of Tokyo, 456 Higashi-Mozumi, Kamioka-cho, Hida-shi, Gifu 506-1205 (Japan)], E-mail: takeuchi@icrr.u-tokyo.ac.jp

    2008-07-15

    Super-Kamiokande-III (SK-III) has been started its observation in July 2006. The main targets of low-energy neutrinos are the solar neutrinos and the diffuse supernova neutrino background. In this paper, the current status of the solar neutrino observation in SK-III is reported.

  1. Pseudo-Dirac neutrinos as a potential complete solution to the neutrino oscillation puzzle

    CERN Document Server

    Geiser, A

    1998-01-01

    A solution for the neutrino mass and mixing pattern is proposed which is compatible with all available experimental data on neutrino oscillations. This solution involves Majorana neutrinos of the pseudo-Dirac type, i.e. $m_{\\rm Majorana} \\ll m_{\\rm Dirac}$. The solar and atmospheric neutrino observations are mainly explained as $\

  2. Neutrino Interactions

    Energy Technology Data Exchange (ETDEWEB)

    Kamyshkov, Yuri [Univ. of Tennesse, Knoxville, TN (United States); Handler, Thomas [Univ. of Tennesse, Knoxville, TN (United States)

    2016-10-24

    The neutrino group of the University of Tennessee, Knoxville was involved from 05/01/2013 to 04/30/2015 in the neutrino physics research funded by DOE-HEP grant DE-SC0009861. Contributions were made to the Double Chooz nuclear reactor experiment in France where second detector was commissioned during this period and final series of measurements has been started. Although Double Chooz was smaller experimental effort than competitive Daya Bay and RENO experiments, its several advantages make it valuable for understanding of systematic errors in measurements of neutrino oscillations. Double Chooz was the first experiment among competing three that produced initial result for neutrino angle θ13 measurement, giving other experiments the chance to improve measured value statistically. Graduate student Ben Rybolt defended his PhD thesis on the results of Double Chooz experiment in 2015. UT group has fulfilled all the construction and analysis commitments to Double Chooz experiment, and has withdrawn from the collaboration by the end of the mentioned period to start another experiment. Larger effort of UT neutrino group during this period was devoted to the participation in another DOE-HEP project - NOvA experiment. The 14,000-ton "FAR" neutrino detector was commissioned in northern Minnesota in 2014 together with 300-ton "NEAR" detector located at Fermilab. Following that, the physics measurement program has started when Fermilab accelerator complex produced the high-intensity neutrino beam propagating through Earth to detector in MInnessota. UT group contributed to NOvA detector construction and developments in several aspects. Our Research Associate Athanasios Hatzikoutelis was managing (Level 3 manager) the construction of the Detector Control System. This work was successfully accomplished in time with the commissioning of the detectors. Group was involved in the development of the on-line software and study of the signatures of the cosmic ray backgrounds

  3. Small Neutrino Masses: Another Anthropic principle aspect?

    CERN Document Server

    Sivaram, C; O, Kiren

    2016-01-01

    This year's Physics Nobel prize for the discovery of neutrino oscillations which resolved the problem of the missing solar neutrinos and the atmospheric muon neutrinos implies that at least one of the three neutrino species has a tiny mass. The neutrino oscillations measure the mass difference squared, and the individual neutrino masses have yet to be accurately ascertained. Particle theory has so far not given a predictive picture for neutrino masses. Here we propose that the anthropic principle may be relevant, as it is frequently invoked to understand other aspects of the universe, including the precise values of fine structure constant or nuclear coupling constant or even the proton-electron mass ratio.

  4. High energy-resolution measurement of the 82Se(3He,t )82Br reaction for double-β decay and for solar neutrinos

    Science.gov (United States)

    Frekers, D.; Alanssari, M.; Adachi, T.; Cleveland, B. T.; Dozono, M.; Ejiri, H.; Elliott, S. R.; Fujita, H.; Fujita, Y.; Fujiwara, M.; Hatanaka, K.; Holl, M.; Ishikawa, D.; Matsubara, H.; Okamura, H.; Puppe, P.; Suda, K.; Tamii, A.; Thies, J.; Yoshida, H. P.

    2016-07-01

    A high-resolution (3He,t ) charge-exchange experiment at an incident energy of 420 MeV has been performed on the double beta (β β ) decay nucleus 82Se. A detailed Gamow-Teller (GT-) strength distribution in 82Br has been extracted, which provides information to the β β -decay nuclear matrix elements. Three strong and isolated transitions, which are to the 75, 1484 and the 2087 keV states in 82Br, are found to dominate the low-excitation region below ≈2.1 MeV. Above 2.1 MeV a sudden onset of a strong GT fragmentation is observed. The degree of fragmentation resembles a situation found in the neighboring A =76 system 76Ge, whereas the observed concentration of strength in the three low-lying states is reminiscent of the heavier neighbors 96Zr and 100Mo. The strong GT transition to the 75 keV ( 1+) state makes 82Se interesting for solar neutrino detection. The 82Se(νe,e-)82Br solar neutrino capture rate in a nonoscillation scenario is therefore evaluated to 668 ±12 (stat)±60 (sys) SNU, and some of the advantages of using selenium for solar neutrino studies are discussed.

  5. Cosmic Neutrinos

    Energy Technology Data Exchange (ETDEWEB)

    Quigg, Chris; /Fermilab /CERN

    2008-02-01

    I recall the place of neutrinos in the electroweak theory and summarize what we know about neutrino mass and flavor change. I next review the essential characteristics expected for relic neutrinos and survey what we can say about the neutrino contribution to the dark matter of the Universe. Then I discuss the standard-model interactions of ultrahigh-energy neutrinos, paying attention to the consequences of neutrino oscillations, and illustrate a few topics of interest to neutrino observatories. I conclude with short comments on the remote possibility of detecting relic neutrinos through annihilations of ultrahigh-energy neutrinos at the Z resonance.

  6. Phenomenology of Pseudo Dirac Neutrinos

    CERN Document Server

    Joshipura, A S; Joshipura, Anjan S.; Rindani, Saurabh D.

    2000-01-01

    We formulate general conditions on $3\\times 3$ neutrino mass matrices under which a degenerate pair of neutrinos at a high scale would split at low scale by radiative corrections involving only the standard model fields. This generalizes the original observations of Wolfenstein on pseudo Dirac neutrinos to three generations. A specific model involving partially broken discrete symmetry and solving the solar and atmospheric anomalies is proposed. The symmetry pattern of the model naturally generates two large angles one of which can account for the large angle MSW solution to the solar neutrino problem.

  7. Neutrino telescopes

    CERN Document Server

    Carr, J

    2002-01-01

    This review presents the scientific objectives and status of Neutrino Telescope Projects. The science program of these projects covers: neutrino astronomy, dark matter searches and measurements of neutrino oscillations. The two neutrino telescopes in operation: AMANDA and BAIKAL will be described together with the ANTARES neutrino telescope being built in the Mediterranean. (18 refs).

  8. The Jiangmen Underground Neutrino Observatory

    Energy Technology Data Exchange (ETDEWEB)

    Sawatzki, Julia [Technische Universitaet Muenchen, Physik Department E15, James-Franck-Strasse 1, 85748 Garching (Germany)

    2016-07-01

    The Jiangmen Underground Neutrino Observatory (JUNO) is a next-generation medium-baseline reactor neutrino experiment located in southern China, close to Kaiping. The construction of the 700 m deep underground facility already started and the experiment is scheduled to start data-taking in 2020, and is expected to operate for at least 20 years. The 20 kt liquid scintillator detector will detect low-energy neutrinos with an unprecedented energy resolution of 3% (at 1 MeV). The primary experimental goal is the determination of the neutrino mass hierarchy at 3σ significance from the measurement of the reactor neutrino energy spectrum. Two nuclear power plants: Yangjiang and Taishan are located at a distance of ∝ 53 km from the detector. Moreover, JUNO will measure the solar neutrino mixing parameters and the atmospheric neutrino squared-mass splitting with a precision < 1%. In addition, supernova neutrinos, geo-neutrinos, sterile neutrinos as well as solar and atmospheric neutrinos can be studied. This talk reviews the status of the project and highlight important scientific objectives.

  9. Letter of Intent: Jinping Neutrino Experiment

    CERN Document Server

    ,

    2016-01-01

    Jinping Neutrino Experiment (Jinping) is proposed to significantly improve measurements on solar neutrinos and geoneutrinos in China Jinping Laboratory - a lab with a number of unparalleled features, thickest overburden, lowest reactor neutrino background, etc., which identify it as the world-best low-energy neutrino laboratory. The proposed experiment will have target mass of 4 kilotons of liquid scintillator or water-based liquid scintillator, with a fiducial mass of 2 kilotons for neutrino-electron scattering events and 3 kilotons for inverse-beta interaction events. A number of initial sensitivities studies have been carried out, including on the transition phase for the solar neutrinos oscillation from the vacuum to the matter effect, the discovery of solar neutrinos from the carbon-nitrogen-oxygen (CNO) cycle, the resolution of the high and low metallicity hypotheses, and the unambiguous separation on U and Th cascade decays from the dominant crustal anti-electron neutrinos in China.

  10. Solar neutrinos, helicity effects and new affine gravity with torsion II

    CERN Document Server

    Alvarez-Castillo, David; Zamora-Saa, Jilberto

    2016-01-01

    The cross section for neutrino helicity spin- flip obtained from a new f(R, T) model of gravitation with dynamic torsion field introduced by one of the authors in [1], is phenomenologically analyzed. To this end, due the logarithmically energy dependence of the cross section, the relation with the axion decay constant fa (Peccei-Quinn parameter) is used. Consequently the link with the phenomenological energy/mass window is found from the astrophysical and high energy viewpoint. The highest helicity spin- flip cross-sectional values presented in this work coincides with a recent estimation on the axion mass computed in [2] in the framework of finite temperature extended lattice QCD and under cosmological considerations.

  11. Comments on the determination of the neutrino mass ordering in reactor neutrino experiments

    CERN Document Server

    Bilenky, S M

    2016-01-01

    We consider the problem of determination of the neutrino mass ordering via precise study of the vacuum neutrino oscillations in the JUNO and other future medium baseline reactor neutrino experiments. We are proposing to resolve neutrino mass ordering by determination of the neutrino oscillation parameters from analysis of the data of the reactor experiments and comparison them with the oscillation parameters obtained from analysis of the solar and KamLAND experiments.

  12. Texture of a Four-Neutrino Mass Matrix

    CERN Document Server

    Mohanty, S; Sarkar, U; Mohanty, Subhendra; Sarkar, Utpal

    1998-01-01

    We propose a simple texture of the neutrino mass matrix with one sterile neutrino along with the three standard ones. It gives maximal mixing angles for with only four parameters, this mass matrix can explain the solar neutrino anomaly, atmospheric neutrino anomaly, LSND result and the hot dark matter of the universe, while satisfying all other Laboratory constraints. Depending on the choice of parameters, one can get the vacuum oscillation or the large angle MSW solution of the solar neutrino anomaly.

  13. Neutrino Physics

    CERN Document Server

    Gil-Botella, I

    2013-01-01

    The fundamental properties of neutrinos are reviewed in these lectures. The first part is focused on the basic characteristics of neutrinos in the Standard Model and how neutrinos are detected. Neutrino masses and oscillations are introduced and a summary of the most important experimental results on neutrino oscillations to date is provided. Then, present and future experimental proposals are discussed, including new precision reactor and accelerator experiments. Finally, different approaches for measuring the neutrino mass and the nature (Majorana or Dirac) of neutrinos are reviewed. The detection of neutrinos from supernovae explosions and the information that this measurement can provide are also summarized at the end.

  14. Comparative Analysis of Brookhaven National Laboratory Nuclear Decay Data and Super-Kamiokande Neutrino Data: Indication of a Solar Connection

    CERN Document Server

    Sturrock, P A

    2015-01-01

    An experiment carried out at the Brookhaven National Laboratory from February 1982 to December 1989 acquired 364 measurements of the beta-decay rates of a sample of 36Cl and of a sample of 32Si. The experimenters reported finding small periodic annual deviations of the data points from an exponential decay - of uncertain origin. We here analyze this dataset by power spectrum analysis and by forming spectrograms and phasegrams. We confirm the occurrence of annual oscillations but we also find evidence of oscillations in a band of frequencies appropriate for the internal rotation of the Sun. Both datasets show clear evidence of a transient oscillation with a frequency of 12.7 cycles per year that falls in the range of rotational frequencies for the solar radiative zone. We repeat these analyses for 358 neutrino measurements acquired by Super-Kamiokande over the interval May 1986 to August 2001. Spectrogram analysis yields a strong and steady oscillation at about 9.5 cycles per year and an intermittent oscillati...

  15. Development of InP solid state detector and liquid scintillator containing metal complex for measurement of pp/7Be solar neutrinos and neutrinoless double beta decay

    Science.gov (United States)

    Fukuda, Yoshiyuki; Moriyama, Shigetaka

    2012-07-01

    A large volume solid state detector using a semi-insulating Indium Phosphide (InP) wafer have been developed for measurement of pp/7Be solar neutrinos. Basic performance such as the charge collection efficiency and the energy resolution were measured by 60% and 20%, respectively. In order to detect two gammas (115keV and 497keV) from neutrino capture, we have designed hybrid detector which consist InP detector and liquid xenon scintillator for IPNOS experiment. New InP detector with thin electrode (Cr 50Å- Au 50Å). For another possibility, an organic liquid scintillator containing indium complex and zirconium complex were studied for a measurement of low energy solar neutrinos and neutrinosless double beta decay, respectively. Benzonitrile was chosen as a solvent because of good solubility for the quinolinolato complexes (2 wt%) and of good light yield for the scintillation induced by gamma-ray irradiation. The photo-luminescence emission spectra of InQ3 and ZrQ4 in benzonitrile was measured and liquid scintillator cocktail using InQ3 and ZrQ4 (50mg) in benzonitrile solutions (20 mL) with secondary scintillators with PPO (100mg) and POPOP (10mg) was made. The energy spectra of incident gammas were measured, and they are first results of the gamma-ray energy spectra using luminescent of metal complexes.

  16. Explosive nucleosynthesis in the neutrino-driven aspherical supernova explosion of a non-rotating 15$M_{\\odot}$ star with solar metallicity

    CERN Document Server

    Fujimoto, Shin-ichiro; Hashimoto, Masa-aki; Ono, Masaomi; Ohnishi, Naofumi

    2011-01-01

    We investigate explosive nucleosynthesis in a non-rotating 15$M_\\odot$ star with solar metallicity that explodes by a neutrino-heating supernova (SN) mechanism aided by both standing accretion shock instability (SASI) and convection. To trigger explosions in our two-dimensional hydrodynamic simulations, we approximate the neutrino transport with a simple light-bulb scheme and systematically change the neutrino fluxes emitted from the protoneutron star. By a post-processing calculation, we evaluate abundances and masses of the SN ejecta for nuclei with the mass number $\\le 70$ employing a large nuclear reaction network. Aspherical abundance distributions, which are observed in nearby core-collapse SN remnants, are obtained for the non-rotating spherically-symmetric progenitor, due to the growth of low-mode SASI. Abundance pattern of the supernova ejecta is similar to that of the solar system for models whose masses ranges $(0.4-0.5) \\Ms$ of the ejecta from the inner region ($\\le 10,000\\km$) of the precollapse ...

  17. Fluorine in the Solar Neighborhood: No Evidence for the Neutrino Process

    Science.gov (United States)

    Jönsson, H.; Ryde, N.; Spitoni, E.; Matteucci, F.; Cunha, K.; Smith, V.; Hinkle, K.; Schultheis, M.

    2017-01-01

    Asymptotic giant branch (AGB) stars are known to produce “cosmic” fluorine, but it is uncertain whether these stars are the main producers of fluorine in the solar neighborhood or if any of the other proposed formation sites, Type II supernovae (SNe II) and/or Wolf-Rayet (W-R) stars, are more important. Recent articles have proposed both AGB stars and SNe II as the dominant sources of fluorine in the solar neighborhood. In this paper we set out to determine the fluorine abundance in a sample of 49 nearby, bright K giants for which we previously have determined the stellar parameters, as well as alpha abundances homogeneously from optical high-resolution spectra. The fluorine abundance is determined from a 2.3 μm HF molecular line observed with the spectrometer Phoenix. We compare the fluorine abundances with those of alpha-elements mainly produced in SNe II and find that fluorine and the alpha-elements do not evolve in lockstep, ruling out SNe II as the dominating producers of fluorine in the solar neighborhood. Furthermore, we find a secondary behavior of fluorine with respect to oxygen, which is another evidence against the SNe II playing a large role in the production of fluorine in the solar neighborhood. This secondary behavior of fluorine will put new constraints on stellar models of the other two suggested production sites: AGB stars and W-R stars.

  18. Neutrinos Are Nearly Dirac Fermions

    CERN Document Server

    Cahill, K E

    1999-01-01

    Neutrino masses and mixings are analyzed in terms of left-handed fields and a 6x6 complex symmetric mass matrix whose singular values are the neutrino masses. An angle theta_nu characterizes the kind of the neutrinos, with theta_nu = 0 for Dirac neutrinos and theta_nu = pi/2 for Majorana neutrinos. If theta_nu = 0, then baryon-minus-lepton number is conserved. When theta_nu is approximately zero, the six neutrino masses coalesce into three nearly degenerate pairs. Thus the smallness of the differences in neutrino masses exhibited in the solar and atmospheric neutrino experiments and the stringent limits on neutrinoless double-beta decay are naturally explained if B-L is approximately conserved and neutrinos are nearly Dirac fermions. If one sets theta_nu = 0.0005, suppresses inter-generational mixing, and imposes a quark-like mass hierarchy, then one may fit the essential features of the solar, reactor, and atmospheric neutrino experiments with otherwise random mass matrices in the eV range. This B-L model le...

  19. Neutrino masses and mixing in supersymmetric theories

    Indian Academy of Sciences (India)

    Sudhir K Vempati

    2000-07-01

    It has been known for sometime that supersymmetric theories with -parity violation provide a natural framework where small neutrino masses can be generated. We discuss neutrino masses and mixing in these theories in the presence of trilinear lepton number violating couplings. It will be shown that simultaneous solutions to solar and atmospheric neutrino problems can be realized in these models.

  20. Neutrino spectrum from theory and experiments

    Indian Academy of Sciences (India)

    Anjan S Joshipura

    2000-01-01

    The observed deficits in the solar and atmospheric neutrino fluxes along with the accelerator results on neutrino oscillations significantly constrain possible mass and mixing patterns among neutrinos. We discuss possible patterns emerging from the experimental results and review theoretical attempts to understand them.

  1. Branch II : Neutrino Oscillations at Low Energies

    Energy Technology Data Exchange (ETDEWEB)

    Cabrera, A., E-mail: anatael@in2p3.fr [CNRS/IN2P3. Laboratoire d' Astro-Particule et Cosmologie. 10 rue Alice Domont et Leonie Duquet. Paris. 75205. Cedex 13 (France); Volpe, C., E-mail: volpe@ipno.in2p3.fr [Institut de Physique Nucleaire Orsay and University of Paris XI,CNRS/IN2P3, F-91406 Orsay cedex (France)

    2011-08-15

    We summarize here briefly the experimental and theoretical results presented at the NOW2010 workshop during the parallel session Branch II 'Oscillations at low energies'. The topics have covered open problems and recent advances in solar neutrinos, reactor and geo-neutrinos, as well as neutrinos from core-collapse supernovae.

  2. Neutrino-driven explosion of a 20 solar-mass star in three dimensions enabled by strange-quark contributions to neutrino-nucleon scattering

    CERN Document Server

    Melson, Tobias; Bollig, Robert; Hanke, Florian; Marek, Andreas; Mueller, Bernhard

    2015-01-01

    Interactions with neutrons and protons play a crucial role for the neutrino opacity of matter in the supernova core. Their current implementation in many simulation codes, however, is rather schematic and ignores not only modifications for the correlated nuclear medium of the nascent neutron star, but also free-space corrections from nucleon recoil, weak magnetism or strange quarks, which can easily add up to changes of several 10% for neutrino energies in the spectral peak. In the Garching supernova simulations with the Prometheus-Vertex code, such sophistications have been included for a long time except for the strange-quark contributions to the nucleon spin, which affect neutral-current neutrino scattering. We demonstrate on the basis of a 20 Msun progenitor star that a moderate strangeness-dependent contribution of g_a^s = -0.2 to the axial-vector coupling constant g_a = 1.26 can turn an unsuccessful three-dimensional (3D) model into a successful explosion. Such a modification is well compatible with cur...

  3. Neutrino Physics

    Science.gov (United States)

    Lederman, L. M.

    1963-01-09

    The prediction and verification of the neutrino are reviewed, together with the V A theory for its interactions (particularly the difficulties with the apparent existence of two neutrinos and the high energy cross section). The Brookhaven experiment confirming the existence of two neutrinos and the cross section increase with momentum is then described, and future neutrino experiments are considered. (D.C.W.)

  4. Neutrino oscillations and the seesaw origin of neutrino mass

    Science.gov (United States)

    Miranda, O. G.; Valle, J. W. F.

    2016-07-01

    The historical discovery of neutrino oscillations using solar and atmospheric neutrinos, and subsequent accelerator and reactor studies, has brought neutrino physics to the precision era. We note that CP effects in oscillation phenomena could be difficult to extract in the presence of unitarity violation. As a result upcoming dedicated leptonic CP violation studies should take into account the non-unitarity of the lepton mixing matrix. Restricting non-unitarity will shed light on the seesaw scale, and thereby guide us towards the new physics responsible for neutrino mass generation.

  5. Neutrino oscillations and the seesaw origin of neutrino mass

    Energy Technology Data Exchange (ETDEWEB)

    Miranda, O.G., E-mail: omr@fis.cinvestav.mx [Departamento de Física, Centro de Investigación y de Estudios Avanzados del IPN, Apdo. Postal 14-740, 07000 Mexico, Distrito Federal (Mexico); Valle, J.W.F. [AHEP Group, Institut de Física Corpuscular – C.S.I.C./Universitat de València, Parc Cientific de Paterna, C/Catedratico José Beltrán, 2, E-46980 Paterna (València) (Spain)

    2016-07-15

    The historical discovery of neutrino oscillations using solar and atmospheric neutrinos, and subsequent accelerator and reactor studies, has brought neutrino physics to the precision era. We note that CP effects in oscillation phenomena could be difficult to extract in the presence of unitarity violation. As a result upcoming dedicated leptonic CP violation studies should take into account the non-unitarity of the lepton mixing matrix. Restricting non-unitarity will shed light on the seesaw scale, and thereby guide us towards the new physics responsible for neutrino mass generation.

  6. Neutrino Masses

    CERN Document Server

    Weinheimer, Christian

    2013-01-01

    The various experiments on neutrino oscillation evidenced that neutrinos have indeed non-zero masses but cannot tell us the absolute neutrino mass scale. This scale of neutrino masses is very important for understanding the evolution and the structure formation of the universe as well as for nuclear and particle physics beyond the present Standard Model. Complementary to deducing constraints on the sum of all neutrino masses from cosmological observations two different methods to determine the neutrino mass scale in the laboratory are pursued: the search for neutrinoless double $\\beta$-decay and the direct neutrino mass search by investigating single $\\beta$-decays or electron captures. The former method is not only sensitive to neutrino masses but also probes the Majorana character of neutrinos and thus lepton number violation with high sensitivity. Currently quite a few experiments with different techniques are being constructed, commissioned or are even running, which aim for a sensitivity on the neutrino ...

  7. Neutrino Anomalies in an Extended Zee Model

    CERN Document Server

    Joshipura, A S; Joshipura, Anjan S.; Rindani, Saurabh D.

    1999-01-01

    We discuss an extended SU(2)X U(1) model which naturally leads to mass scales and mixing angles relevant for understanding both the solar and atmospheric neutrino anomalies. No right-handed neutrinos are introduced in the model.The model uses a softly broken L_e-L_{\\mu}-L_{\\tau} symmetry. Neutrino masses arise only at the loop level. The one-loop neutrino masses which arise as in the Zee model solve the atmospheric neutrino anomaly while breaking of L_e-L_{\\mu}-L_{\\tau} generates at two-loop order a mass splitting needed for the vacuum solution of the solar neutrino problem. A somewhat different model is possible which accommodates the large-angle MSW resolution of the solar neutrino problem.

  8. Neutrino masses in astrophysics and cosmology

    Energy Technology Data Exchange (ETDEWEB)

    Raffelt, G.G. [Max-Planck-Institut fuer Physik, Muenchen (Germany)

    1996-11-01

    Astrophysical and cosmological arguments and observations give us the most restrictive constraints on neutrino masses, electromagnetic couplings, and other properties. Conversely, massive neutrinos would contribute to the cosmic dark-matter density and would play an important role for the formation of structure in the universe. Neutrino oscillations may well solve the solar neutrino problem, and can have a significant impact on supernova physics. (author) 14 figs., tabs., 33 refs.

  9. Overview of the T2K long baseline neutrino oscillation experiment

    CERN Document Server

    Le, Trung

    2009-01-01

    Neutrino oscillations were discovered by atmospheric and solar neutrino experiments, and have been confirmed by experiments using neutrinos from accelerators and nuclear reactors. It has been found that there are large mixing angles in the $\

  10. Reactor Neutrinos

    OpenAIRE

    Lasserre, T.; Sobel, H.W.

    2005-01-01

    We review the status and the results of reactor neutrino experiments, that toe the cutting edge of neutrino research. Short baseline experiments have provided the measurement of the reactor neutrino spectrum, and are still searching for important phenomena such as the neutrino magnetic moment. They could open the door to the measurement of coherent neutrino scattering in a near future. Middle and long baseline oscillation experiments at Chooz and KamLAND have played a relevant role in neutrin...

  11. Neutrino physics

    Energy Technology Data Exchange (ETDEWEB)

    Harris, Deborah A.; /Fermilab

    2008-09-01

    The field of neutrino physics has expanded greatly in recent years with the discovery that neutrinos change flavor and therefore have mass. Although there are many neutrino physics results since the last DIS workshop, these proceedings concentrate on recent neutrino physics results that either add to or depend on the understanding of Deep Inelastic Scattering. They also describe the short and longer term future of neutrino DIS experiments.

  12. Why Is The Neutrino Oscillation Formula Expanded In $\\Delta m_{21}^{2}/\\Delta m_{31}^{2}$ Still Accurate Near The Solar Resonance In Matter?

    CERN Document Server

    Xu, Xun-Jie

    2015-01-01

    The traditional approximate formula for neutrino oscillation in matter which is obtained from the expansion in terms of the ratio of mass square differences $\\alpha=\\Delta m_{21}^{2}/\\Delta m_{31}^{2}\\approx0.03$, first proposed by Cervera, et al and Freund, turns out to be an accurate formula for accelerator neutrino experiments. It is accurate not only at energies well above the solar resonance as required by the validity of the $\\alpha-$expansion but also at energies near the solar resonance which is just the case of the T2K experiment. Due to the non-perturbative effect of the solar resonance, the $\\alpha-$expansion in this case is invalid but this formula was recently used in T2K. This paper analytically justifies the use of this formula in T2K by careful dealing with the singularity originated from the branch cut in the roots of the equation for the eigenvalues. Besides, we also propose some simple but more accurate formulae which provide possible alternatives to the traditional formula.

  13. Measurement of Day and Night Neutrino Energy Spectra at SNO and Constraints on Neutrino Mixing Parameters

    CERN Document Server

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

    2002-01-01

    The Sudbury Neutrino Observatory (SNO) has measured day and night solar neutrino energy spectra and rates. For charged current events, assuming an undistorted $^8$B spectrum, the night minus day rate is $14.0% \\pm 6.3% ^{+1.5}_{-1.4}%$ of the average rate. If the total flux of active neutrinos is additionally constrained to have no asymmetry, the $\

  14. Neutrino physics

    CERN Document Server

    Hernandez, P

    2016-01-01

    This is the writeup of the lectures on neutrino physics delivered at various schools: TASI and Trieste in 2013 and the CERN-Latin American School in 2015. The topics discussed in this lecture include: general properties of neutrinos in the SM, the theory of neutrino masses and mixings (Dirac and Majorana), neutrino oscillations both in vacuum and in matter, as well as an overview of the experimental evidence for neutrino masses and of the prospects in neutrino oscillation physics. We also briefly review the relevance of neutri- nos in leptogenesis and in beyond-the-Standard-Model physics.

  15. Neutrino Interactions

    CERN Document Server

    McFarland, Kevin

    2008-01-01

    This manuscript summarizes a series of three lectures on interactions of neutrinos . The lectures begin with a pedagogical foundation and then explore topics of interest to current and future neutrino oscillation and cross-section experiments.

  16. Magnus approximation for neutrino oscillations with three flavors in matter

    Energy Technology Data Exchange (ETDEWEB)

    Aguilar-Arevalo, Alexis A; D' Olivo, Juan Carlos, E-mail: alexis@nucleares.unam.m, E-mail: dolivo@nucleares.unam.m [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Apartado Postal 70-543, 04510, Distrito Federal (Mexico)

    2010-01-01

    The Magnus expansion of the evolution operator is used to find approximate analytical solutions to the problem of three neutrino oscillations in matter with varying density. Survival probabilities are calculated for the case of solar and supernova neutrinos.

  17. Neutrino Physics

    CERN Document Server

    Xing, Zhi-Zhong

    2014-01-01

    I give a theoretical overview of some basic properties of massive neutrinos in these lectures. Particular attention is paid to the origin of neutrino masses, the pattern of lepton flavor mixing, the feature of leptonic CP violation and the electromagnetic properties of massive neutrinos. I highlight the TeV seesaw mechanisms as a possible bridge between neutrino physics and collider physics in the era characterized by the Large Hadron Collider.

  18. Neutrino anomalies and large extra dimensions

    CERN Document Server

    Dighe, A S; Dighe, Amol S.; Joshipura, Anjan S.

    2001-01-01

    Theories with large extra dimensions can generate small neutrino masses when the standard model neutrinos are coupled to singlet fermions propagating in higher dimensions. The couplings can also generate mass splittings and mixings among the flavour neutrinos in the brane. We systematically study the minimal scenario involving only one singlet bulk fermion coupling weakly to the flavour neutrinos. We explore the neutrino mass structures in the brane that can potentially account for the atmospheric, solar and LSND anomalies simultaneously in a natural way. We demonstrate that in the absence of a priori mixings among the SM neutrinos, it is not possible to reconcile all these anomalies. The presence of some structure in the mass matrix of the SM neutrinos can solve this problem. This is exemplified by the Zee model, which when embedded in extra dimensions in a minimal way can account for all the neutrino anomalies.

  19. Neutrino Radar

    CERN Document Server

    Panigrahi, P K

    2002-01-01

    We point out that with improving our present knowledge of experimental neutrino physics it will be possible to locate nuclear powered vehicles like submarines, aircraft carriers and UFOs and detect nuclear testing. Since neutrinos cannot be shielded, it will not be possible to escape these detection. In these detectors it will also be possible to perform neutrino oscillation experiments during any nuclear testing.

  20. Neutrino Physics

    CERN Document Server

    Langacker, P; Peinado, E; Langacker, Paul; Erler, Jens; Peinado, Eduardo

    2005-01-01

    The theoretical and experimental bases of neutrino mass and mixing are reviewed. A brief chronological evolution of the weak interactions, the electroweak Standard Model, and neutrinos is presented. Dirac and Majorana mass terms are explained as well as models such as the seesaw mechanism. Schemes for two, three and four neutrino mixings are presented.

  1. A predictive scheme for neutrino masses

    CERN Document Server

    Joshipura, A S; Joshipura, Anjan S.; Rindani, Saurabh D.

    2002-01-01

    The solar and atmospheric data and possibly large value for the effective neutrino mass in neutrinoless double beta decay experiment together indicate that all the three neutrinos are nearly degenerate. A verifiable texture for the neutrino mass matrix is proposed to accommodate these results. This texture allows almost degenerate neutrino masses two of which are exactly degenerate at tree level. The standard model radiative corrections lift this degeneracy and account for the solar deficit. The solar scale is correlated with the effective neutrino mass $m_{ee}$ probed in neutrinoless double beta decay experiments. The model can accommodate a large value of O(eV) for $m_{ee}$. Six observables corresponding to three neutrino masses and three mixing angles are determined in terms of only three unknown parameters within the proposed texture.

  2. Generalized mass ordering degeneracy in neutrino oscillation experiments

    CERN Document Server

    Coloma, Pilar

    2016-01-01

    We consider the impact of neutral-current (NC) non-standard neutrino interactions (NSI) on the determination of the neutrino mass ordering. We show that in presence of NSI there is an exact degeneracy which makes it impossible to determine the neutrino mass ordering and the octant of the solar mixing angle $\\theta_{12}$ at oscillation experiments. The degeneracy holds at the probability level and for arbitrary matter density profiles, and hence, solar, atmospheric, reactor, and accelerator neutrino experiments are affected simultaneously. The degeneracy requires order-one corrections from NSI to the NC electron neutrino--quark interaction and can be tested in electron neutrino NC scattering experiments.

  3. Generalized mass ordering degeneracy in neutrino oscillation experiments

    Science.gov (United States)

    Coloma, Pilar; Schwetz, Thomas

    2016-09-01

    We consider the impact of neutral-current (NC) nonstandard neutrino interactions (NSI) on the determination of the neutrino mass ordering. We show that in the presence of NSI there is an exact degeneracy which makes it impossible to determine the neutrino mass ordering and the octant of the solar mixing angle θ12 at oscillation experiments. The degeneracy holds at the probability level and for arbitrary matter density profiles, and hence solar, atmospheric, reactor, and accelerator neutrino experiments are affected simultaneously. The degeneracy requires order-1 corrections from NSI to the NC electron neutrino-quark interaction and can be tested in electron neutrino NC scattering experiments.

  4. La Thuile 2014: Theoretical premises to neutrino round table

    CERN Document Server

    Vissani, Francesco

    2014-01-01

    This talk, dedicated to the memory of G. Giacomelli, introduced the round table on neutrinos held in February 2014. The topics selected for the discussion are: 1) the neutrinoless double beta decay rate (interpretation in terms of light neutrinos, nuclear uncertainties); 2) the physics in the gigantic water Cherenkov detectors (proton decay, atmospheric neutrinos); 3) the study of neutrino oscillations (mass hierarchy and CP violation; other neutrino states); 4) the neutrino astronomy at low and high energies (solar, supernova, cosmic neutrinos). The importance of an active interplay between theory and experiment is highlighted.

  5. Perspectives on Finding the Neutrino Nature

    CERN Document Server

    Czakon, M; Gluza, J

    2000-01-01

    The possibility of determining the neutrino nature is considered in view of the most recent experimental observations. The analysis combines schemes with three and four neutrinos.The data on oscillations is put together with that from the search of neutrinoless double beta decay and results on tritium beta decay. All solar neutrino oscillation solutions are taken into account. The sensitivity of the problem on future experimental bounds from GENIUS is studied. Dirac neutrinos are shown to be unavoidable already at present in some schemes and the constraints will quickly become more stringent with future data. The consequences of including bounds from Cosmology on the neutrino content of Hot Dark Matter are commented.

  6. Supernova neutrinos and explosive nucleosynthesis

    Energy Technology Data Exchange (ETDEWEB)

    Kajino, T. [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan and Department of Astronomy, Graduate School of Science, The University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033 (Japan); Aoki, W. [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Cheoun, M.-K. [Department of Physics, Soongsil University, Seoul 156-743 (Korea, Republic of); Hayakawa, T. [Japan Atomic Energy Agency, Shirakara-Shirane 2-4, Tokai-mura, Ibaraki 319-1195 (Japan); Hidaka, J.; Hirai, Y.; Shibagaki, S. [National Astronomical Observatory, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Mathews, G. J. [Center for Astrophysics, Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States); Nakamura, K. [Faculty of Science and Engineering, Waseda University, Ohkubo 3-4-1, Shinjuku, Tokyo 169-8555 (Japan); Suzuki, T. [Department of Physics, College of Humanities and Sciences, Nihon University, Sakurajosui 3-25-40, Setagaya-ku, Tokyo 156-8550 (Japan)

    2014-05-09

    Core-collapse supernovae eject huge amount of flux of energetic neutrinos. We studied the explosive nucleosyn-thesis in supernovae and found that several isotopes {sup 7}Li, {sup 11}B, {sup 92}Nb, {sup 138}La and {sup 180}Ta as well as r-process nuclei are affected by the neutrino interactions. The abundance of these isotopes therefore depends strongly on the neutrino flavor oscillation due to the Mikheyev-Smirnov-Wolfenstein (MSW) effect. We discuss first how to determine the neutrino temperatures in order to explain the observed solar system abundances of these isotopes, combined with Galactic chemical evolution of the light nuclei and the heavy r-process elements. We then study the effects of neutrino oscillation on their abundances, and propose a novel method to determine the still unknown neutrino oscillation parameters, mass hierarchy and θ{sub 13}, simultaneously. There is recent evidence that SiC X grains from the Murchison meteorite may contain supernova-produced light elements {sup 11}B and {sup 7}Li encapsulated in the presolar grains. Combining the recent experimental constraints on θ{sub 13}, we show that our method sug-gests at a marginal preference for an inverted neutrino mass hierarchy. Finally, we discuss supernova relic neutrinos that may indicate the softness of the equation of state (EoS) of nuclear matter as well as adiabatic conditions of the neutrino oscillation.

  7. Future of neutrino experiments

    Indian Academy of Sciences (India)

    Takaaki Kajita

    2009-01-01

    Atmospheric, solar, reactor and accelerator neutrino oscillation experiments have measured $ m_{12}^{2}$, sin2 12, $| m_{23}^{2} |$ and sin2 223. The next stage of the oscillation studies should be the observation of a finite sin2 213. If a non-zero sin2 213 is observed, the subsequent goals should be the observation of the CP violation and the determination sign of $ m_{23}^{2}$. Possible future neutrino oscillation experiments that could assess these questions are discussed.

  8. Neutrino Lensing

    Institute of Scientific and Technical Information of China (English)

    LUO Xin-Lian

    2009-01-01

    Due to the intrinsic properties of neutrinos, the gravitational lens effect for a neutrino should be more colorful and meaningful than the normal lens effect of a photon. Other than the experiments operated at terrestrial laboratory, in principle, we can propose a completely new astrophysical method to determine not only the nature of the gravity of lens objects but also the mixing parameters of neutrinos by analyzing neutrino trajectories near the central objects.However, the angular, energy and time resolution of the neutrino telescopes are still comparatively poor, so we just concentrate on the two classical tests of general relativity, i.e.the angular deflection and the time delay of the neutrino by a lens object as a preparative work in this paper.In addition, some simple properties of neutrino lensing are investigated.

  9. Neutrino Factory

    CERN Document Server

    Bogomilov, M; Tsenov, R; Dracos, M; Bonesini, M; Palladino, V; Tortora, L; Mori, Y; Planche, T; Lagrange, J  B; Kuno, Y; Benedetto, E; Efthymiopoulos, I; Garoby, R; Gilardoini, S; Martini, M; Wildner, E; Prior, G; Blondel, A; Karadzhow, Y; Ellis, M; Kyberd, P; Bayes, R; Laing, A; Soler, F  J  P; Alekou, A; Apollonio, M; Aslaninejad, M; Bontoiu, C; Jenner, L  J; Kurup, A; Long, K; Pasternak, J; Zarrebini, A; Poslimski, J; Blackmore, V; Cobb, J; Tunnell, C; Andreopoulos, C; Bennett, J  R  J; Brooks, S; Caretta, O; Davenne, T; Densham, C; Edgecock, T  R; Fitton, M; Kelliher, D; Loveridge, P; McFarland, A; Machida, S; Prior, C; Rees, G; Rogers, C; Rooney, M; Thomason, J; Wilcox, D; Booth, C; Skoro, G; Back, J  J; Harrison, P; Berg, J  S; Fernow, R; Gallardo, J  C; Gupta, R; Kirk, H; Simos, N; Stratakis, D; Souchlas, N; Witte, H; Bross, A; Geer, S; Johnstone, C; Mokhov, N; Neuffer, D; Popovic, M; Strait, J; Striganov, S; Morfín, J  G; Wands, R; Snopok, P; Bogacz, S  A; Morozov, V; Roblin, Y; Cline, D; Ding, X; Bromberg, C; Hart, T; Abrams, R  J; Ankenbrandt, C  M; Beard, K  B; Cummings, M  A  C; Flanagan, G; Johnson, R  P; Roberts, T  J; Yoshikawa, C  Y; Graves, V  B; McDonald, K  T; Coney, L; Hanson, G

    2014-01-01

    The properties of the neutrino provide a unique window on physics beyond that described by the standard model. The study of subleading effects in neutrino oscillations, and the race to discover CP-invariance violation in the lepton sector, has begun with the recent discovery that $\\theta_{13} > 0$. The measured value of $\\theta_{13}$ is large, emphasizing the need for a facility at which the systematic uncertainties can be reduced to the percent level. The neutrino factory, in which intense neutrino beams are produced from the decay of muons, has been shown to outperform all realistic alternatives and to be capable of making measurements of the requisite precision. Its unique discovery potential arises from the fact that only at the neutrino factory is it practical to produce high-energy electron (anti)neutrino beams of the required intensity. This paper presents the conceptual design of the neutrino factory accelerator facility developed by the European Commission Framework Programme 7 EURO$\

  10. Gauge mediated supersymmetry breaking and neutrino anomalies

    CERN Document Server

    Joshipura, A S; Joshipura, Anjan S.; Vempati, Sudhir K.

    1999-01-01

    Supersymmetric standard model with softly broken lepton symmetry provides a suitable framework to accommodate the solar and atmospheric neutrino anomalies. This model contains a natural explanation for large mixing and hierarchal masses without fine tuning of the parameters. Neutrino spectrum is particularly constrained in the minimal messenger model (MMM) of gauge mediated SUSY breaking, since all SUSY breaking effects are controlled in MMM by a single parameter. We study the structure of neutrino masses and mixing both in MMM and in simple extensions of it in the context of solar and atmospheric neutrino anomalies.

  11. Measurements of the atmospheric neutrino flux by Super-Kamiokande: energy spectra, geomagnetic effects, and solar modulation

    CERN Document Server

    Richard, E; Abe, K; Haga, Y; Hayato, Y; Ikeda, M; Iyogi, K; Kameda, J; Kishimoto, Y; Miura, M; Moriyama, S; Nakahata, M; Nakajima, T; Nakano, Y; Nakayama, S; Orii, A; Sekiya, H; Shiozawa, M; Takeda, A; Tanaka, H; Tomura, T; Wendell, R A; Akutsu, R; Irvine, T; Kajita, T; Kaneyuki, K; Nishimura, Y; Labarga, L; Fernandez, P; Gustafson, J; Kachulis, C; Kearns, E; Raaf, J L; Stone, J L; Sulak, L R; Berkman, S; Nantais, C M; Tanaka, H A; Tobayama, S; Goldhaber, M; Kropp, W R; Mine, S; Weatherly, P; Smy, M B; Sobel, H W; Takhistov, V; Ganezer, K S; Hartfiel, B L; Hill, J; Hong, N; Kim, J Y; Lim, I T; Park, R G; Himmel, A; Li, Z; OSullivan, E; Scholberg, K; Walter, C W; Wongjirad, T; Ishizuka, T; Tasaka, S; Jang, J S; Learned, J G; Matsuno, S; Smith, S N; Friend, M; Hasegawa, T; Ishida, T; Ishii, T; Kobayashi, T; Nakadaira, T; Nakamura, K; Oyama, Y; Sakashita, K; Sekiguchi, T; Tsukamoto, T; Suzuki, A T; Takeuchi, Y; Yano, T; Cao, S V; Hiraki, T; Hirota, S; Huang, K; Kikawa, T; Minamino, A; Nakaya, T; Suzuki, K; Fukuda, Y; Choi, K; Itow, Y; Suzuki, T; Mijakowski, P; Frankiewicz, K; Hignight, J; Imber, J; Jung, C K; Li, X; Palomino, J L; Wilking, M J; Yanagisawa, C; Fukuda, D; Ishino, H; Kayano, T; Kibayashi, A; Koshio, Y; Mori, T; Sakuda, M; Xu, C; Kuno, Y; Tacik, R; Kim, S B; Okazawa, H; Choi, Y; Nishijima, K; Koshiba, M; Totsuka, Y; Suda, Y; Yokoyama, M; Bronner, C; Hartz, M; Martens, K; Marti, Ll; Suzuki, Y; Vagins, M R; Martin, J F; Konaka, A; Chen, S; Zhang, Y; Wilkes, R J

    2015-01-01

    A comprehensive study on the atmospheric neutrino flux in the energy region from sub-GeV up to several TeV using the Super-Kamiokande water Cherenkov detector is presented in this paper. The energy and azimuthal spectra of the atmospheric ${\

  12. Lorentz noninvariant oscillations of massless neutrinos are excluded

    CERN Document Server

    Barger, Vernon; Marfatia, Danny; Whisnant, Kerry

    2011-01-01

    The bicycle model of Lorentz noninvariant neutrino oscillations without neutrino masses naturally predicts maximal mixing and a 1/E dependence of the oscillation argument for muon-neutrino to tau-neutrino oscillations of atmospheric and long-baseline neutrinos, but cannot also simultaneously fit the data for solar neutrinos and KamLAND. We search for other possible structures of the effective Hamiltonian for Lorentz noninvariant oscillations of massless neutrinos that naturally have a 1/E dependence at high neutrino energy. Due to the lack of any evidence for direction dependence, we consider only direction-independent oscillations. Although we find a number of models with a 1/E dependence for atmospheric and long-baseline neutrinos, none can also simultaneously fit solar and KamLAND data.

  13. The Jiangmen Underground Neutrino Observatory

    CERN Document Server

    Grassi, Marco

    2016-01-01

    The Jiangmen Underground Neutrino Observatory (JUNO) is a large and high precision liquid scintillator detector under construction in the south of China. With its 20 kt target mass, it aims to achieve an unprecedented 3% energy resolution at 1 MeV. Its main goal is to study the disappearance of reactor antineutrino to determine the neutrino mass ordering, and to precisely measure the mixing parameters $\\theta_{12}$, $\\Delta m^2_{12}$, and $\\Delta m ^2_{ee}$. It also aims to detect neutrinos emitted from radioactive processes taking place within the inner layers of the Earth (geonutrinos), as well as neutrinos produced during rare supernova bursts. Neutrinos emitted in solar nuclear reactions could also be observed, if stringent radiopurity requirements on the scintillator are met. This manuscript provides some highlights of JUNO's Physics Programme, and describes the detector design, as well as the ongoing detector R&D.

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

    Science.gov (United States)

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

    2017-03-01

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

  15. Astrophysics and neutrinos

    CERN Document Server

    Harigel, G G

    1997-01-01

    This seminar is primarily intended for CERN guides. The formation of sun-like stars, their life cycle, and their final destiny will be explained in simple terms, appropriate for the majority of our visitors. An overview of the nuclear reaction chains in our sun will presented (Standard Solar Model), with special emphasis on the production of neutrinos and their measurement in underground detectors. These detectors are also able to record high-energy cosmic neutrinos. Since many properties of neutrinos are still unknown, a brief description of table-top and nuclear reactor experiments is included, as well as those using beams from particle accelerators. Measurements with a variety of space telescopes complement the knowledge of our universe, previously limited to the visible range of the electromagnetic spectrum.

  16. Neutrino Oscillations With Two Sterile Neutrinos

    Science.gov (United States)

    Kisslinger, Leonard S.

    2016-10-01

    This work estimates the probability of μ to e neutrino oscillation with two sterile neutrinos using a 5×5 U-matrix, an extension of the previous estimate with one sterile neutrino and a 4×4 U-matrix. The sterile neutrino-active neutrino mass differences and the mixing angles of the two sterile neutrinos with the three active neutrinos are taken from recent publications, and the oscillation probability for one sterile neutrino is compared to the previous estimate.

  17. Neutrino Oscillations With Two Sterile Neutrinos

    CERN Document Server

    Kisslinger, Leonard S

    2016-01-01

    This work estimates the probability of $\\mu$ to $e$ neutrino oscillation with two sterile neutrinos using a 5x5 U-matrix, an extension of the previous estimate with one sterile neutrino and a 4x4 U-matrix. The sterile neutrino-active neutrino mass differences and the mixing angles of the two sterile neutrinos with the three active neutrinos are taken from recent publications, and the oscillation probability for one sterile neutrino is compared to the previous estimate.

  18. Three dimensional calculation of flux of low energy atmospheric neutrinos

    Science.gov (United States)

    Lee, H.; Bludman, S. A.

    1985-01-01

    Results of three-dimensional Monte Carlo calculation of low energy flux of atmospheric neutrinos are presented and compared with earlier one-dimensional calculations 1,2 valid at higher neutrino energies. These low energy neutrinos are the atmospheric background in searching for neutrinos from astrophysical sources. Primary cosmic rays produce the neutrino flux peaking at near E sub=40 MeV and neutrino intensity peaking near E sub v=100 MeV. Because such neutrinos typically deviate by 20 approximately 30 from the primary cosmic ray direction, three-dimensional effects are important for the search of atmospheric neutrinos. Nevertheless, the background of these atmospheric neutrinos is negligible for the detection of solar and supernova neutrinos.

  19. Neutrino Oscillations: A Global Analysis

    CERN Document Server

    Fogli, G L; Marrone, A; Montanino, D; Palazzo, A; Rotunno, A M

    2003-01-01

    We review the status of the neutrino oscillation physics (as of June 2003), with a particular emphasis on the present knowledge of the neutrino mass-mixing parameters in a three generation approach. We consider first the nu_mu-->nu_tau flavor transitions of atmospheric neutrinos. It is found that standard oscillations provide the best description of the SK+K2K data, and that the associated mass-mixing parameters are determined at 1 sigma (and dof=1) as: Delta m^2=(2.6 +-0.4) x 10^-3 eV^2 and sin^2(2theta)=1.00+0.00-0.05. Such indications, presently dominated by SK, could be strengthened by further K2K data. Then we analyze the energy spectrum of reactor neutrino events recently observed at KamLAND and combine them with solar and terrestrial neutrino data. We find that the solution to the solar neutrino problem at large mixing angle (LMA) is basically split into two sub-regions, that we denote as LMA-I and LMA-II. The LMA-I solution, characterized by lower values of the squared neutrino mass gap, is favored by...

  20. Reactor Neutrinos

    Directory of Open Access Journals (Sweden)

    Soo-Bong Kim

    2013-01-01

    Full Text Available We review the status and the results of reactor neutrino experiments. Short-baseline experiments have provided the measurement of the reactor neutrino spectrum, and their interest has been recently revived by the discovery of the reactor antineutrino anomaly, a discrepancy between the reactor neutrino flux state of the art prediction and the measurements at baselines shorter than one kilometer. Middle and long-baseline oscillation experiments at Daya Bay, Double Chooz, and RENO provided very recently the most precise determination of the neutrino mixing angle θ13. This paper provides an overview of the upcoming experiments and of the projects under development, including the determination of the neutrino mass hierarchy and the possible use of neutrinos for society, for nonproliferation of nuclear materials, and geophysics.