WorldWideScience

Sample records for solar neutrino observation

  1. Solar neutrino observations and neutrino oscillations

    International Nuclear Information System (INIS)

    Kuo, T.K.; Pantaleone, J.

    1990-01-01

    The results of recent Kamiokande-II and 37 Cl solar-neutrino experiments are quantitatively analyzed assuming the Mikheyev-Smirnov-Wolfenstein solution to the solar-neutrino problem. It is found that the parameter region known as the ''large mass'' solution to the solar-neutrino problem is disfavored by a little more than 1 σ while the ''small mass'' and ''large angle'' solutions are in good agreement at this level. The implications on this analysis from time variations in the data are discussed

  2. 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.

  3. Solar neutrinos

    International Nuclear Information System (INIS)

    Phillips, R.J.N.

    1987-09-01

    The problem with solar neutrinos is that there seem to be too few of them, at least near the top end of the spectrum, since the 37 Cl detector finds only about 35% of the standard predicted flux. Various kinds of explanation have been offered: (a) the standard solar model is wrong, (b) neutrinos decay, (c) neutrinos have magnetic moments, (d) neutrinos oscillate. The paper surveys developments in each of these areas, especially the possible enhancement of neutrino oscillations by matter effects and adiabatic level crossing. The prospects for further independent experiments are also discussed. (author)

  4. Molybdenum solar neutrino experiment

    International Nuclear Information System (INIS)

    Wolfsberg, K.; Cowan, G.A.; Bryant, E.A.

    1984-01-01

    The goal of the molybdenum solar neutrino experiment is to deduce the 8 B solar neutrino flux, averaged over the past several million years, from the concentration of 98 Tc in a deeply buried molybdenum deposit. The experiment is important to an understanding of stellar processes because it will shed light on the reason for the discrepancy between theory and observation of the chlorine solar neutrino experiment. Possible reasons for the discrepancy may lie in the properties of neutrinos (neutrino oscillations or massive neutrinos) or in deficiencies of the standard solar model. The chlorine experiment only measures the 8 B neutrino flux in current times and does not address possible temporal variations in the interior of the sun, which are also not considered in the standard model. In the molybdenum experiment, we plan to measure 98 Tc (4.2 Myr), also produced by 8 B neutrinos, and possibly 97 Tc (2.6 Myr), produced by lower energy neutrinos

  5. Solar neutrinos

    International Nuclear Information System (INIS)

    Schatzman, E.

    1983-01-01

    The solar energy is produced by a series of nuclear reactions taking place in the deep interior of the sun. Some of these reactions produce neutrinos which may be detected, the proper detection system being available. The results of the Davis experiment (with 37 Cl) are given, showing a deficiency in the solar neutrino flux. The relevant explanation is either a property of the neutrino or an important change in the physics of the solar models. The prospect of a new experiment (with 71 Ga) is important as it will decide which of the two explanations is correct [fr

  6. 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.)

  7. Solar neutrino

    Energy Technology Data Exchange (ETDEWEB)

    Sugimoto, D [Tokyo Univ. (Japan). Coll. of General Education

    1975-01-01

    The measurement of solar neutrino was performed by using the reaction /sup 37/cl+..nu..sub(e)..-->../sup 37/Ar+e/sup -/ by Davis et al. The argon gas produced through the above mentioned reaction in a tank containing 610 ton of C/sub 2/Cl/sub 4/ was collected and measured. The rate of production of /sup 37/Ar was 0.13+-0.20/day, and the net production rate by the solar neutrino was 0.06+-0.20/day, being corrected for background. This value corresponds to 0.5+-1.0 SNU. Theoretical calculation with the model of spherically symmetric solar development gave an expected value of 5.6 SNU, which is in contradiction with the experimental value. Reason of this discrepancy was considered. The possibility of decay of neutrino to the other particles with weak interaction is very slight. Various models of the sun were investigated, but the results were still inconsistent with the experiment. The mixing of matters in the sun may cause the reduction of neutrino. If He gas comes to the center of the sun by mixing, the reaction, /sup 3/He+/sup 3/He, progresses excessively at the center, and it produces the expansion of the core of the sun. Then, the temperature drops and the neutrino is reduced. Various models which can explain the neutrino of less than ISNU have been presented. However, other theory says that the reduction of neutrino is not expected even if the mixing is considered. A problem concerning the mixing is whether the thermal instability which causes the mixing exists. (Kato, T.).

  8. Solar Neutrinos

    Indian Academy of Sciences (India)

    7,81. The Chlorine experiment, located in the Homestake Gold Mine in Lead, South Dakota, was the first solar neutrino experiment to be set up. A tank of. 105 gallons of perchloroethylene in which the electron neu- trino reacts with chlorine to ...

  9. The solar neutrino problem

    International Nuclear Information System (INIS)

    Bahcall, J.N.

    1986-01-01

    The observed capture rate for solar neutrinos in the /sup 37/Cl detector is lower than the predicted capture rate. This discrepancy between theory and observation is known as the 'solar neutrino problem.' The author reviews the basic elements in this problem: the detector efficiency, the theory of stellar (solar) evolution, the nuclear physics of energy generation, and the uncertainties in the predictions. He also answers the questions of: So What? and What Next?

  10. 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.

  11. Bruno Pontecorvo and solar neutrinos

    International Nuclear Information System (INIS)

    MCDONALD, A. B.

    2014-01-01

    Bruno Pontecorvo had a very substantial impact on measurements of solar neutrinos, proposing a technique in 1948 that led to measurements by Davis and proposing that neutrinos could oscillate, a process that has been found to influence observed fluxes substantially. The past history and future prospects of solar neutrino measurements are reviewed, including a discussion of the contributions by Pontecorvo.

  12. Solar neutrino experiments: An update

    International Nuclear Information System (INIS)

    Hahn, R.L.

    1993-01-01

    The situation in solar neutrino physics has changed drastically in the past few years, so that now there are four neutrino experiments in operation, using different methods to look at different regions of the solar neutrino energy spectrum. These experiments are the radiochemical 37 Cl Homestake detector, the realtime Kamiokande detector, and the different forms of radiochemical 71 Ga detectors used in the GALLEX and SAGE projects. It is noteworthy that all of these experiments report a deficit of observed neutrinos relative to the predictions of standard solar models (although in the case of the gallium detectors, the statistical errors are still relatively large). This paper reviews the basic principles of operation of these neutrino detectors, reports their latest results and discusses some theoretical interpretations. The progress of three realtime neutrino detectors that are currently under construction, SuperKamiok, SNO and Borexino, is also discussed

  13. Solar neutrino experiments: An update

    Energy Technology Data Exchange (ETDEWEB)

    Hahn, R.L.

    1993-12-31

    The situation in solar neutrino physics has changed drastically in the past few years, so that now there are four neutrino experiments in operation, using different methods to look at different regions of the solar neutrino energy spectrum. These experiments are the radiochemical {sup 37}Cl Homestake detector, the realtime Kamiokande detector, and the different forms of radiochemical {sup 71}Ga detectors used in the GALLEX and SAGE projects. It is noteworthy that all of these experiments report a deficit of observed neutrinos relative to the predictions of standard solar models (although in the case of the gallium detectors, the statistical errors are still relatively large). This paper reviews the basic principles of operation of these neutrino detectors, reports their latest results and discusses some theoretical interpretations. The progress of three realtime neutrino detectors that are currently under construction, SuperKamiok, SNO and Borexino, is also discussed.

  14. The search for solar neutrinos

    International Nuclear Information System (INIS)

    Ryder, L.

    1976-01-01

    The pioneering work on the detection of solar neutrinos by R. Davis is discussed. The discrepancy between the theoretical neutrino flux rate, according to a recent standard solar model, of 5.6 solar neutrino units (SNU) and the observed rate of 1 SNU together with three suggested solutions of the discrepancy are examined. Very recently Davis has announced an increased count rate of about 4 SNU while groups in Birmingham and in the Crimea have reported solar oscillations. The impact of these latest developments is discussed. (U.K.)

  15. The solar neutrinos epopee

    CERN Document Server

    Lasserre, T

    2003-01-01

    The 2002 year has been fruitful for the neutrino physics. First, the Sudbury Neutrino Observatory (SNO) experiment has shown that the electron neutrinos nu sub e emitted by the sun are converted into muon neutrinos (nu submu) and tau neutrinos (nu subtau), thus closing the 30 years old problem of solar neutrinos deficit. This discovery validates the model of nuclear energy production inside the sun but it shakes the theory describing the weak interactions between the fundamental constituents of matter. This theory considers the neutrinos (and the photons) as massless particles, while the taste conversion phenomenon necessarily implies that neutrinos have a mass. In October 2000, the Universe exploration by the cosmic neutrinos is jointly recognized by R. Davis (USA) and M. Koshiba (Japan) who received the Nobel price of physics. Finally, in December 2000, the KamLAND experiment quantitatively demonstrated the neutrinos metamorphosis by detecting a deficit in the flux of electron antineutrinos coming from the ...

  16. Solar neutrino experiments

    International Nuclear Information System (INIS)

    Hampel, W.

    1996-01-01

    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 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

  17. 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.

  18. Solar neutrinos and gravity

    International Nuclear Information System (INIS)

    Kuo, T.K.

    2001-01-01

    We review the possibility that the solar neutrino problem can be explained by neutrinos violating the equivalence principle. It is found that such a scenario can be ruled out when one takes into account data from high energy accelerator neutrino experiments

  19. Toward observational neutrino astrophysics

    International Nuclear Information System (INIS)

    Koshiba, M.

    1988-01-01

    It is true that: (1) The first observation of the neutrino burst from the supernova SN1987a by Kamiokande-II which was immediately confirmed by IBM; and (2) the first real-time, directional, and spectral observation of solar 8 B neutrinos also by Kamiokande-II could perhaps be considered as signalling the birth of observational astrophysics. The field, however, is still in its infancy and is crying out for tender loving care. Namely, while the construction of astronomy requires the time and the direction of the signal and that of astrophysics requires, in addition to the spectral information, the observations of (1) could not give the directional information and the results of both (1) and (2) are still suffering from the meager statistics. How do we remedy this situation to let this new born science of observational neutrino astrophysics grow healthy. This is what the author addresses in this talk. 15 refs., 8 figs

  20. Constraining neutrino magnetic moment with solar and reactor neutrino data

    OpenAIRE

    Tortola, M. A.

    2004-01-01

    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 MU...

  1. Neutrino magnetic moments and the solar neutrino problem

    Energy Technology Data Exchange (ETDEWEB)

    Akhmedov, E.Kh. [Washington Univ., Seattle, WA (United States). Inst. for Nuclear Theory]|[Valencia Univ. (Spain). Dept. de Fisica Teorica

    1994-08-01

    Present status of the neutrino magnetic moment solutions of the solar neutrino problem is reviewed. In particular, we discuss a possibility of reconciling different degrees of suppression and time variation of the signal (or lack of such a variation) observed in different solar neutrino experiments. It is shown that the resonant spin-flavor precession of neutrinos due to the interaction of their transitions magnetic moments with solar magnetic field can account for all the available solar neutrino data. For not too small neutrino mixing angles (sin 2{theta}{sub o} {approx_gt} 0.2 the combined effect of the resonant spin-flavor precession and neutrino oscillations can result in an observable flux of solar {bar {nu}}{sub e}`s.

  2. Neutrino magnetic moments and the solar neutrino problem

    International Nuclear Information System (INIS)

    Akhmedov, E.Kh.; Valencia Univ.

    1994-01-01

    Present status of the neutrino magnetic moment solutions of the solar neutrino problem is reviewed. In particular, we discuss a possibility of reconciling different degrees of suppression and time variation of the signal (or lack of such a variation) observed in different solar neutrino experiments. It is shown that the resonant spin-flavor precession of neutrinos due to the interaction of their transitions magnetic moments with solar magnetic field can account for all the available solar neutrino data. For not too small neutrino mixing angles (sin 2θ o approx-gt 0.2 the combined effect of the resonant spin-flavor precession and neutrino oscillations can result in an observable flux of solar bar ν e 's

  3. Neutrino mass and the solar neutrino problem

    International Nuclear Information System (INIS)

    Wolfenstein, L.

    1987-01-01

    Theoretical ideas about neutrino mass based on grand-unified theories are reviewed. These give the see-saw formula in which neutrino mass is inversely proportional to a large mass scale M. For M between 10/sup 11/ and 10/sup 15/ Gev the study of solar neutrinos appears to be the best probe of neutrino masses and mixings

  4. Solar neutrino detection

    International Nuclear Information System (INIS)

    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. The solar neutrino problem

    International Nuclear Information System (INIS)

    Zatsepin, G.

    1982-01-01

    The problem of missing solar neutrinos is reviewed and discussed. The experiments of the 70s show a solar neutrino flux to be 4 times lower than the flux predicted by the standard model of the Sun. The three possible origins of this contradiction are analysed: the cross sections of nuclear reactions going on in the internal region of the Sun must be remeasured; the unknown properties of neutrino, like neutrino oscillation or decay, must be investigated theoretically and experimentally; or the standard model of the Sun must be changed, e.g. by a periodically pulsating star model or by a model describing periodic admixtures of He-3 to the central region of the Sun. Some new models and newly proposed experiments are described. The importance of new electronic detection methods of neutrinos is underlined. (D.Gy.)

  6. Solar neutrino results from SAGE

    International Nuclear Information System (INIS)

    Gavrin, V.N.

    2001-01-01

    The results of ten years of solar neutrino observation by the Russian-American gallium solar neutrino experiment (SAGE) are reported. The overall result of 70 runs during the measurement period from January 1990 to October 1999 is 75.4 -6.8 +7.0 (stat.) -3.0 +3.5 (syst) SNU. This represents only slightly more than half of the predicted standard solar model rate of 129 SNU. The individual results on each run, and the results of combined analysis of all runs during each year, as well as the results of combined analysis of all runs during monthly and bimonthly periods are presented

  7. Solar neutrino results from SAGE

    International Nuclear Information System (INIS)

    Gavrin, V.N.

    2000-01-01

    We report the results of ten years of solar neutrino observation by the Russian-American Gallium solar neutrino Experiment (SAGE). The overall result of 70 runs during the measurement period January 1990 to October 1999 is 75.4 + 7.0/-6.8 (stat.) +3.5/-3.0 (syst.) SNU. This represents only slightly more than half of the predicted standard solar model rate of 129 SNU. The individual results of each run, and the results of combined analysis of all runs during each year, as well as the results of combined analysis of all runs during monthly and bimonthly periods are presented

  8. Geo-neutrino Observation

    International Nuclear Information System (INIS)

    Dye, S. T.; Alderman, M.; Batygov, M.; Learned, J. G.; Matsuno, S.; Mahoney, J. M.; Pakvasa, S.; Rosen, M.; Smith, S.; Varner, G.; McDonough, W. F.

    2009-01-01

    Observations of geo-neutrinos measure radiogenic heat production within the earth, providing information on the thermal history and dynamic processes of the mantle. Two detectors currently observe geo-neutrinos from underground locations. Other detection projects in various stages of development include a deep ocean observatory. This paper presents the current status of geo-neutrino observation and describes the scientific capabilities of the deep ocean observatory, with emphasis on geology and neutrino physics.

  9. Chlorine solar neutrino experiment

    International Nuclear Information System (INIS)

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

    1984-01-01

    The chlorine solar neutrino experiment in the Homestake Gold Mine is described and the results obtained with the chlorine detector over the last fourteen years are summarized and discussed. Background processes producing 37 Ar and the question of the constancy of the production rate of 37 Ar are given special emphasis

  10. 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.

  11. Neutrino Observations from the Sudbury Neutrino Observatory

    Science.gov (United States)

    Q. R. Ahmad, R. C. Allen, T. C. Andersen, J. D. Anglin, G. B?hler, 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.

  12. The solar neutrino problem after the GALLEX artificial neutrino source experiment

    International Nuclear Information System (INIS)

    Vignaud, D.

    1995-01-01

    Using an intense 51 Cr artificial neutrino source (more than 60 PBq), the GALLEX solar neutrino collaboration has recently checked that its radiochemical detector was fully efficient for the detection of solar neutrinos. After this crucial result, the status of the solar neutrino problem is reviewed, with emphasis on how neutrino oscillations may explain (through the MSW effect) the different deficits observed in the four existing experiments. (author). 25 refs., 5 figs., 1 tab

  13. Radiochemical solar neutrino experiments

    International Nuclear Information System (INIS)

    Rich, R.; Spiro, M.

    1993-01-01

    This review covers the three presently running radiochemical solar neutrino experiments, namely the Chlorine, SAGE, and GALLEX experiments. The focus of the review is on a discussion of statistical consistency checks of the available data. The chlorine radiochemical experiment is conceptually simple and shows no strong indication of any statistical anomalies. It still forms the basis of the solar neutrino problem. Each of the two gallium experiments show internal statistical consistency. SAGE's recent preliminary results are consistent with the published GALLEX results. If this convergence is confirmed by a more definitive analysis, this would suggest that the combined result of the two gallium experiments, SAGE and GALLEX, be used for comparisons with theoretical expectations. 5 refs., 15 figs

  14. 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.)

  15. History of the problem of solar neutrinos

    International Nuclear Information System (INIS)

    Bakal, D.N.; Dehvis, R.

    1986-01-01

    The history of solar neutrino physics is briefly outlined. The period from 1962 to the present time is considered. The values of predicted and observed rates of neutrino capture which have been published for 1964-1980 are presented. The rates of 37 Ar formation in a reservoir with liquid containing 37 Cl are reviewed. The average value of 37 Ar formation rate, found on the basis of the data, constitutes 2.2±0.4 SUN, where SUN - solar unit of neutrino flux (1 SUN=10 36 neutrino capture for a second per atom)

  16. The indium solar neutrino project

    International Nuclear Information System (INIS)

    Booth, N.E.; Salmon, G.L.; Hukin, D.A.

    1984-01-01

    The only way to resolve the solar neutrino puzzle is to perform a new experiment. It is shown that 115 In has unique possibilities as a target for solar neutrino detection. Progress in developing a detector based on 115 In is reviewed and future plans are outlined. (author)

  17. Neutrino-electron scattering and the choice between different MSW solutions of the solar neutrino problem

    International Nuclear Information System (INIS)

    Rosen, S.P.; Gelb, J.M.

    1987-01-01

    We consider the scattering of solar neutrinos by electrons as a means for distinguishing between MSW solutions of the solar neutrino problem. In terms of the ratio R between the observed cross-section and that for pure electron-type neutrinos, we find that some correlation between the value R and the appropriate solution. 9 refs., 3 figs

  18. An Experimentalist's Overview of Solar Neutrinos

    Science.gov (United States)

    Oser, Scott M.

    2012-02-01

    Four decades of solar neutrino research have demonstrated that solar models do a remarkable job of predicting the neutrino fluxes from the Sun, to the extent that solar neutrinos can now serve as a calibrated neutrino source for experiments to understand neutrino oscillations and mixing. In this review article I will highlight the most significant experimental results, with emphasis on the latest model-independent measurements from the Sudbury Neutrino Observatory. The solar neutrino fluxes are seen to be generally well-determined experimentally, with no indications of time variability, while future experiments will elucidate the lower energy part of the neutrino spectrum, especially pep and CNO neutrinos.

  19. An Experimentalist's Overview of Solar Neutrinos

    International Nuclear Information System (INIS)

    Oser, Scott M

    2012-01-01

    Four decades of solar neutrino research have demonstrated that solar models do a remarkable job of predicting the neutrino fluxes from the Sun, to the extent that solar neutrinos can now serve as a calibrated neutrino source for experiments to understand neutrino oscillations and mixing. In this review article I will highlight the most significant experimental results, with emphasis on the latest model-independent measurements from the Sudbury Neutrino Observatory. The solar neutrino fluxes are seen to be generally well-determined experimentally, with no indications of time variability, while future experiments will elucidate the lower energy part of the neutrino spectrum, especially pep and CNO neutrinos.

  20. Proposed geological solar neutrino measurement

    International Nuclear Information System (INIS)

    Cowan, G.A.; Haxton, W.C.

    1982-01-01

    It may be possible to measure the boron-8 solar neutrino flux, averaged over the past several million years, from the concentration of technetium-98 in molybdenum-rich ore. This geochemical experiment could provide the first test of nonstandard solar models that suggest a relation between the chlorine-37 solar neutrino puzzle and the most recent glacial epoch. The necessary conditions for achieving a meaningful measurement are identified and discussed

  1. Report on solar neutrino experiments

    International Nuclear Information System (INIS)

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

    1984-01-01

    A summary is given of the status of solar neutrino research that includes results of the Brookhaven chlorine detector, a discussion of the development of the gallium, bromine, and lithium radiochemical detectors, and some proposals for direct counting detectors. The gallium and bromine radiochemical detectors are developed and are capable of giving critical information of interest about neutrino physics and the fusion reactions in the interior of the sun. A plan for building these detectors is outlined and a rough cost estimate is given. A review is given of the plans in the Soviet Union in solar neutrino research

  2. Solar neutrino results from SAGE

    International Nuclear Information System (INIS)

    Gavrin, V.N.

    1999-01-01

    We report the status of the Russian-American Gallium solar neutrino Experiment (SAGE). The solar neutrino result for SAGE III, 20 runs during the measuring period May 1995 through December 1997, is 56.7 +9.3/-8.7(stat.)+4.6/-4.8(syst.) SNU. The combined result for 57 measurements from 1990 through 1997 (SAGE I+II+III) is 66.9 +7.1/-6.8 (stat) +5.4/-5.7 (syst) SNU. The final result of the SAGE 51 Cr experiment to check the response of SAGE to low energy neutrinos is also presented

  3. Solar neutrinos, helioseismology and the solar internal dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Turck-Chieze, Sylvaine [Service d' Astrophysique/IRFU/DSM/CEA, 91191 Gif sur Yvette Cedex (France); Couvidat, Sebastien, E-mail: sylvaine.turck-chieze@cea.fr, E-mail: couvidat@stanford.edu [HEPL, Stanford University, Stanford, CA 94305 (United States)

    2011-08-15

    Neutrinos are fundamental particles ubiquitous in the Universe and whose properties remain elusive despite more than 50 years of intense research activity. This review illustrates the importance of solar neutrinos in astrophysics, nuclear physics and particle physics. After a description of the historical context, 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 with 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 and gravity waves propagating in the Sun. This seismic model contributed to the stabilization of the neutrino flux predictions. This review recalls the main historical steps, from the pioneering Homestake mine experiment and the GALLEX-SAGE experiments capturing the first proton-proton neutrinos. It emphasizes the importance of the SuperKamiokande and SNO detectors. Both experiments demonstrated that the solar-emitted electron neutrinos are partially transformed into other neutrino flavors before reaching the Earth. This sustained experimental effort opens the door to neutrino astronomy, with long-base lines and underground detectors. The success of BOREXINO in detecting the {sup 7}Be neutrino signal alone instills confidence in physicists' ability to detect each neutrino source separately. It justifies the building of a new generation of detectors to measure the entire solar neutrino spectrum in greater detail, as well as supernova neutrinos. A coherent picture has emerged from neutrino physics and helioseismology. Today, new paradigms take shape in these two fields: neutrinos are massive particles, but their

  4. Are solar neutrinos detected by living things

    International Nuclear Information System (INIS)

    Ruderfer, M.

    1975-01-01

    Scattering of electrons by solar neutrinos induces an inherently detectable noise frequency approximately 100 Hz per gram of active mammalian brain tissue based on a scattering cross section previously shown to satisfactorily explain the Davis solar neutrino experiment. (Auth.)

  5. The solar neutrino problem

    International Nuclear Information System (INIS)

    Roxburgh, I.W.

    1981-01-01

    The problems posed by the low flux of neutrinos from the sun detected by Davis and coworkers are reviewed. Several proposals have been advanced to resolve these problems and the more reasonable (in the author's opinion) are presented. Recent claims that the neutrino may have finite mass are also considered. (orig.)

  6. Status of solar neutrino experiments

    International Nuclear Information System (INIS)

    Beier, E.W.; Davis, R. Jr.; Kim, S.B.; Jelley, N.

    1990-01-01

    A summary of the status of four solar neutrino experiments is presented. The Homestake 37 Cl data are presented and the possible time dependence of the data is addressed. Data from 1040 days of operation of the Kamiokande II detector are presented next. The status of the 71 Ga experiment in the Baksan Neutrino Observatory, which has operated for a short time, is discussed. The summary concludes with a discussion of the status of the Sudbury Neutrino Observatory, which has been under construction since the beginning of 1990. 7 refs., 6 figs

  7. Solar neutrino problem

    Energy Technology Data Exchange (ETDEWEB)

    Faulkner, D J [Australian National Univ., Canberra. Mount Stromlo and Siding Spring Observatories

    1975-10-01

    This paper reviews several recent attempts to solve the problem in terms of modified solar interior models. Some of these have removed the count rate discrepancy, but have violated other observational data for the sun. One successfully accounts for the Davis results at the expense of introducing an ad hoc correction with no current physical explanation. An introductory description of the problem is given.

  8. Report on solar-neutrino experiments

    International Nuclear Information System (INIS)

    Davis, R. Jr.

    1982-01-01

    This report on solar neutrino experiments will include a summary of the results of the chlorine detector, and an account of our plans to build a gallium solar neutrino experiment. In addition to discussing the experimental side of the solar neutrino problem I would like to relate our experiences during the last 15 years in working in the Homestake Gold Mine. In the course of our work at Homestake a number of independent groups have asked to use our facilities and, because of the cooperative and helpful attitude of the Mine management, these experimentalists could be easily accommodated. A brief account of these experiences may be useful for the main business of this workshop, building large particle detectors for observing nucleon decay, and the related question of the need for a national underground physics facility

  9. 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.

  10. Towards the resolution of the solar neutrino problem

    Energy Technology Data Exchange (ETDEWEB)

    Friedland, Alexander [Univ. of California, Berkeley, CA (United States)

    2000-08-01

    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 (sin2 2θ, Δm2) parameter space. We point out, however, that this parameterization misses the half of the parameter space π/4 < θ < π/2, which is physically inequivalent to the region 0 < θ < π/4 in

  11. Anti-neutrino imprint in solar neutrino flare

    Science.gov (United States)

    Fargion, D.

    2006-10-01

    A future neutrino detector at megaton mass might enlarge the neutrino telescope thresholds revealing cosmic supernova background and largest solar flares (SFs) neutrinos. Indeed the solar energetic (Ep>100 MeV) flare particles (protons, α), while scattering among themselves on solar corona atmosphere must produce prompt charged pions, whose chain decays are source of a solar (electron muon) neutrino 'flare' (at tens or hundreds MeV energy). These brief (minutes) neutrino 'bursts' at largest flare peak may overcome by three to five orders of magnitude the steady atmospheric neutrino noise on the Earth, possibly leading to their detection above detection thresholds (in a full mixed three flavour state). Moreover the birth of anti-neutrinos at a few tens of MeV very clearly flares above a null thermal 'hep' anti-neutrino solar background and also above a tiny supernova relic and atmospheric noise. The largest prompt solar anti-neutrino 'burst' may be well detected in future Super Kamikande (gadolinium implemented) anti-neutrino \\bar\

  12. Violation of Equivalence Principle and Solar Neutrinos

    International Nuclear Information System (INIS)

    Gago, A.M.; Nunokawa, H.; Zukanovich Funchal, R.

    2001-01-01

    We have updated the analysis for the solution to the solar neutrino problem by the long-wavelength neutrino oscillations induced by a tiny breakdown of the weak equivalence principle of general relativity, and obtained a very good fit to all the solar neutrino data

  13. Matter effects on the flavor conversions of solar neutrinos and high-energy astrophysical neutrinos

    Science.gov (United States)

    Huang, Guo-yuan; Liu, Jun-Hao; Zhou, Shun

    2018-06-01

    Can we observe the solar eclipses in the neutrino light? In principle, this is possible by identifying the lunar matter effects on the flavor conversions of solar neutrinos when they traverse the Moon before reaching the detectors at the Earth. Unfortunately, we show that the lunar matter effects on the survival probability of solar 8B neutrinos are suppressed by an additional factor of 1.2%, compared to the day-night asymmetry. However, we point out that the matter effects on the flavor conversions of high-energy astrophysical neutrinos, when they propagate through the Sun, can be significant. Though the flavor composition of high-energy neutrinos can be remarkably modified, it is quite challenging to observe such effects even in the next-generation of neutrino telescopes.

  14. Solar neutrino spectroscopy (before and after superkamiokande)

    International Nuclear Information System (INIS)

    Smirnov, A.Yu.

    1996-11-01

    Results of solar neutrino spectroscopy based on data from four experiments are presented. Perspectives related to forthcoming experiments are discussed. Implications of the results for neutrino properties are considered. (author). 54 refs, 2 tabs

  15. Lepton mixing and the 'solar neutrino puzzle'

    International Nuclear Information System (INIS)

    Bilenky, S.M.; Pontecorvo, B.

    1977-01-01

    The results of the well-known solar neutrino experiments in which the Cl-Ar method was employed are discussed; the results of this experiment gave a too-small neutrino signal and were referred to as the 'solar neutrino puzzle'. A number of explanations have been offered to account for the results, but it is stated that the explanation in terms of lepton mixing and neutrino sterility is attractive in terms of present day elementary particle physics and much more natural than the other explanations offered. Headings are as follows: neutrino oscillations and lepton charge, oscillations and solar neutrino experiments, lepton mixing according to old and present ideas, neutrino oscillations and the 'solar neutrino puzzle'. (U.K.)

  16. MSW effect and solar neutrino experiments

    International Nuclear Information System (INIS)

    Rosen, S.P.

    1986-01-01

    We describe the MSW solutions to the 37 Cl solar neutrino experiment, and their implications for the 71 Ga experiment. Measurement of the spectrum of electron-type neutrinos arriving at earth is emphasized. 8 refs., 2 figs., 1 tab

  17. 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).

  18. Detecting Solar Neutrino Flare in Megaton and km3 detectors

    International Nuclear Information System (INIS)

    Fargion, Daniele; Di Giacomo, Paola

    2009-01-01

    To foresee a solar flare neutrino signal we infer its upper and lower bound. The upper bound was derived since a few years by general energy equipartition arguments on observed solar particle flare. The lower bound, the most compelling one for any guarantee neutrino signal, is derived by most recent records of hard Gamma bump due to solar flare on January 2005 (by neutral pion decay). Because neutral and charged pions (made by hadron scattering in the flare) are born on the same foot, their link is compelling: the observed gamma flux [Grechnev V.V. et al., (arXiv:0806.4424), Solar Physics, Vol. 1, October, (2008), 252] reflects into a corresponding one for the neutrinos, almost one to one. Moreover while gamma photons might be absorbed (in deep corona) or at least reduced inside the flaring plasma, the secondaries neutrino are not. So pion neutrinos should be even more abundant than gamma ones. Tens-hundred MeV neutrinos may cross undisturbed the whole Sun, doubling at least their rate respect a unique solar-side for gamma flare. Therefore we obtain minimal bounds opening a windows for neutrino astronomy, already at the edge of present but quite within near future Megaton neutrino detectors. Such detectors are considered mostly to reveal cosmic supernova background or rare Local Group (few Mpc) Supernovas events [Matthew D. Kistler et al. (0810.1959v1)]. However rarest (once a decade), brief (a few minutes) powerful solar neutrino 'flare' may shine and they may overcome by two to three order of magnitude the corresponding steady atmospheric neutrino noise on the Earth, leading in largest Neutrino detector at least to one or to meaning-full few events clustered signals. The voice of such a solar anti-neutrino flare component at a few tens MeVs may induce an inverse beta decay over a vanishing anti-neutrino solar background. Megaton or even inner ten Megaton Ice Cube detector at ten GeV threshold may also reveal traces in hardest energy of solar flares. Icecube

  19. Solar neutrinos: propsects for detection and implications

    International Nuclear Information System (INIS)

    Haxton, W.C.

    1984-01-01

    From the viewpoint of particle physics, the sun provides us with a high intensity (approx. 10 11 /cm 2 sec) source of neutrinos that have traveled over an interesting distance. We would be remiss not to exploit this opportunity to mount incomparable neutrino oscillation experiments. From the viewpoint of astrophysics, these neutrinos carry, in their flux and energy distribution, a precise record of the thermonuclear reactions that we believe occur in the sun's high-temperature core. They provide a unique, quantitative test of our theories of stellar evolution, and thus of one of the fundamental clocks that monitor the aging of our universe. This information cannot be obtained from conventional observations of the radiation emitted from cool stellar surfaces: solar photons have lost, in their 10 7 year journey outward from the core, all detailed memory of the mechanisms by which they were created. The thesis of this talk is the feasibility, by virtue of several very recent advances in nuclear physics and nuclear chemistry, of a complete program of solar neutrino spectroscopy that will quantitatively test both the standard stellar model and the behavior of low-energy neutrinos over astrophysical distances

  20. A road map to solar neutrino fluxe, neutrino oscillation parameters, and tests for new physics

    CERN Document Server

    Bahcall, J N; Bahcall, John N.; Peña-Garay, Carlos

    2003-01-01

    We analyze all available solar and related reactor neutrino experiments, as well as simulated future ^7Be, p-p, pep, and ^8B solar neutrino experiments. We treat all solar neutrino fluxes as free parameters subject to the condition that the total luminosity represented by the neutrinos equals the observed solar luminosity (the `luminosity constraint'). Existing experiments show that the p-p solar neutrino flux is 1.01 + - 0.02 (1 sigma) times the flux predicted by the BP00 standard solar model; the ^7Be neutrino flux is 0.97^{+0.28}_{-0.54} the predicted flux; and the ^8B flux is 1.01 + - 0.06 the predicted flux. The oscillation parameters are: Delta m^2 = 7.3^{+0.4}_{-0.6} 10^{-5} eV^2 and tan^2 theta_{12} = 0.42^{+0.08}_{-0.06}. We evaluate how accurate future experiments must be to determine more precisely neutrino oscillation parameters and solar neutrino fluxes, and to elucidate the transition from vacuum-dominated to matter-dominated oscillations. A future ^7Be nu-e scattering experiment accurate to + -...

  1. A solar neutrino loophole: standard solar models

    Energy Technology Data Exchange (ETDEWEB)

    Rouse, C A [General Atomic Co., San Diego, Calif. (USA)

    1975-11-01

    The salient aspects of the existence theorem for a unique solution to a system of linear of nonlinear first-order, ordinary differential equations are given and applied to the equilibrium stellar structure equations. It is shown that values of pressure, temperature, mass and luminosity are needed at one point - and for the sun, the logical point is the solar radius. It is concluded that since standard solar model calculations use split boundary conditions, a solar neutrino loophole still remains: solar model calculations that seek to satisfy the necessary condition for a unique solution to the solar structure equations suggest a solar interior quite different from that deduced in standard models. This, in turn, suggests a theory of formation and solar evolution significantly different from the standard theory.

  2. Testing the principle of equivalence by solar neutrinos

    International Nuclear Information System (INIS)

    Minakata, Hisakazu; Washington Univ., Seattle, WA; Nunokawa, Hiroshi; Washington Univ., Seattle, WA

    1994-04-01

    We discuss the possibility of testing the principle of equivalence with solar neutrinos. If there exists a violation of the equivalence principle quarks and leptons with different flavors may not universally couple with gravity. The method we discuss employs a quantum mechanical phenomenon of neutrino oscillation to probe into the non-university of the gravitational couplings of neutrinos. We develop an appropriate formalism to deal with neutrino propagation under the weak gravitational fields of the sun in the presence of the flavor mixing. We point out that solar neutrino observation by the next generation water Cherenkov detectors can improve the existing bound on violation of the equivalence principle by 3-4 orders of magnitude if the nonadiabatic Mikheyev-Smirnov-Wolfenstein mechanism is the solution to the solar neutrino problem

  3. Testing the principle of equivalence by solar neutrinos

    International Nuclear Information System (INIS)

    Minakata, H.; Nunokawa, H.

    1995-01-01

    We discuss the possibility of testing the principle of equivalence with solar neutrinos. If there exists a violation of the equivalence principle, quarks and leptons with different flavors may not universally couple with gravity. The method we discuss employs the quantum mechanical phenomenon of neutrino oscillation to probe into the nonuniversality of the gravitational couplings of neutrinos. We develop an appropriate formalism to deal with neutrino propagation under the weak gravitational fields of the Sun in the presence of the flavor mixing. We point out that solar neutrino observation by the next generation water Cherenkov detectors can place stringent bounds on the violation of the equivalence principle to 1 part in 10 15 --10 16 if the nonadiabatic Mikheyev-Smirnov-Wolfenstein mechanism is the solution to the solar neutrino problem

  4. Solar neutrinos: a scientific puzzle

    International Nuclear Information System (INIS)

    Bahcall, J.N.; Davis, R.

    1975-01-01

    An experiment designed to capture neutrinos produced by solar thermonuclear reactions is a crucial one for the theory of stellar evolution. The conventional wisdom regarding nuclear fusion as the energy source for main sequence stars like the sun is briefly outlined. It is assumed that the sun shines because of fusion reactions similar to those envisioned for terrestrial fusion reactors. The basic solar process is the fusion of four protons to form an alpha particle, two positrons (e + ), and two neutrinos (νsub(e)), i.e., 4p → α + 2e + + 2νsub(e). The principal reactions are shown and the percentage of each reaction is given. Several experiments carried out toward this aim are discussed. (B.G.)

  5. 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.

  6. solar neutrino oscillation phenomenology

    Indian Academy of Sciences (India)

    first present the allowed areas obtained from global solar analysis and demonstrate the preference of the ... We demonstrate through a pro- jected analysis ... 10%) when the same input values of the parameters are used and also demonstrate.

  7. Flipped Heavy Neutrinos from the Solar Neutrino Problem to Baryogenesis

    CERN Document Server

    Ellis, Jonathan Richard; Olive, Keith A

    1993-01-01

    We discuss baryogenesis using the flipped $SU(5)$ model for lepton mass matrices. We show that the generalized see-saw mechanism in this model can not only provide MSW neutrino mixing suitable for solving the solar neutrino problem, and supply a hot dark matter candidate ($\

  8. Solar neutrinos and nonradial solar oscillations

    International Nuclear Information System (INIS)

    Zatsepin, G.T.; Gavryuseva, E.A.; Kopysov, Yu.S.

    1980-01-01

    The problem of origin of surface solar oscillations is considered. It is assumed that generation of oscillations is performed by the solar nucleus. The necessary excitation condition for gravitational oscillations of the solar nucleus is a sharp decrease of the oscillation amplitude outside the nucleus, where the nuclear reaction rates are small and only radiation losses are considerable. It is shown that the specific singularities of gravitational wave propagation in solar entrails permit to attain a significant reduction of the oscillation amplitude. The solar entrails can serve as an effective trap for gravitational waves, if the substance of the solar nucleus is close to the state of convectional equilibrium. In order that the g 1 quadrupole mode of the solar nucleus has a period of 2h 40 min and sharply decreases in the solar mantle, it is enough that only the external part of the solar nucleus is close to the state of convectional equilibrium. Closeness of the solar nucleus to the state of convectional equilibrium is an argument in favour of its periodic mixing. Periodic mixing of the solar nucleus can serve as a cause of a low counting rate of solar neutrinos in R.Davis chlorous detector

  9. Chlorine and bromine solar neutrino experiments

    International Nuclear Information System (INIS)

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

    1985-01-01

    The solar neutrino experiment based upon the neutrino capture reaction 37 Cl (ν, e - ) 37 Ar has been in operation in the Homestake Gold Mine at Lead, South Dakota since 1967. The results of this experiment are well known, and have been reported most recently to the solar neutrino conference at Lead in 1984. We report here the latest results from this experiment. A radiochemical neutrino detector based upon the neutrino capture reaction 81 Br (ν, e - ) 81 Kr* → 81 Kr has recently been shown to be feasible. Our plans for performing a full scale test of the method using the Homestake chlorine detector are discussed briefly. 8 refs

  10. 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.

    2012-02-01

    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±0.6stat±0.3systcounts/(day·100ton). Assuming the pep neutrino flux predicted by the standard solar model, we obtained a constraint on the CNO solar neutrino interaction rate of Mikheyev-Smirnov-Wolfenstein large mixing angle solution to solar neutrino oscillations, these values correspond to solar neutrino fluxes of (1.6±0.3)×108cm-2s-1 and <7.7×108cm-2s-1 (95% C.L.), respectively, in agreement with both the high and low metallicity standard 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.

  11. Round table discussion of future Solar Neutrino Program

    International Nuclear Information System (INIS)

    Anon.

    1978-01-01

    The discussion of the future neutrino program includes a critique of the chlorine-37 experiment and the necessary continued effort, the astronomical and cosmological implications of the various nonstandard models, future programs in laboratory experiments and theoretical calculations on reaction cross sections, opacities, convections, and observations of elemental abundances on the Sun and the meteorites, and lastly the program in solar neutrino research

  12. Report on the Brookhaven solar neutrino experiment

    International Nuclear Information System (INIS)

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

    1976-01-01

    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 37 Cl(ν,e - ) 37 Ar producing the isotope 37 Ar (half life of 35 days). The detector contains 3.8 x 10 5 liters of C 2 Cl 4 (2.2 x 10 30 atoms of 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 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 37 Ar

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

    Science.gov (United States)

    Joshipura, Anjan S.; Massó, Eduard; Mohanty, Subhendra

    2002-12-01

    We examine the constraints on the nonradiative decay of neutrinos from the observations of solar neutrino experiments. The standard oscillation hypothesis among three neutrinos solves the solar and atmospheric neutrino problems. The 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 ν2, τ2/m2>22.7 s/MeV for the Mikheyev-Smirnov-Wolfenstein solution of the solar neutrino problem and τ2/m2>27.8 s/MeV for the vacuum oscillation solution (at 99% C.L.).

  14. 7Be solar neutrino measurement with KamLAND

    Science.gov (United States)

    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.; KamLAND Collaboration

    2015-11-01

    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. 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.

  15. Faraday effect and solar neutrino problem

    International Nuclear Information System (INIS)

    Nawaz, S.

    2001-01-01

    We have studied the Faraday effect and solar neutrino problem. Our main emphasis was on the Faraday rotation of neutrino de Broglie wave of electron-neutrino producing in the nuclear reactions in the sun and converting into any other flavor of neutrino while passing through matter and/or magnetic field of the sun. We have shown that specific Faraday angle can minimize the number of free parameters occurring in the neutrino oscillation. We have also shown that the resonant Faraday angle corresponding to the resonance of MSW effect can be obtained the knowledge of the oscillation parameter delta m/sup 2/ and the neutrino energy. Using neutrino-Faraday angle approach, we have shown that the matter enhanced neutrino oscillations is dominating over the resonant spin flavor precession (RSFP) even in the favorable region of the spin flavor procession. Using the latest solar neutrino data, we have shown that Faraday angle is almost 10/sup -3/ times smaller. This can be interpreted as the interaction of magnetic moment of neutrino with the solar magnetic field is negligibly small as compare to the effect of matter field on the neutrino oscillation. (author)

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

    Science.gov (United States)

    de Holanda, P. C.; Smirnov, A. Yu.

    2004-06-01

    The Homestake result is about ˜2σ lower than the Ar-production rate, QAr, predicted by the large mixing angle (LMA) Mikheyev-Smirnov-Wolfenstein solution of the solar neutrino problem. Also there is no apparent upturn of the energy spectrum (R≡Nobs/NSSM) at low energies in SNO and Super-Kamiokande. Both these facts can be explained if a light, Δm201˜(0.2 2)×10-5 eV2, sterile neutrino exists which mixes very weakly with active neutrinos: sin2 2α˜(10-5 10-3). We perform both the analytical and numerical study of the 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 electron neutrino fluxes. Apart from diminishing QAr it leads to decrease of the Ge-production rate and may lead to the decrease of the BOREXINO signal as well as the CC/NC ratio at SNO. Future studies of the solar neutrinos by SNO, SK, BOREXINO, and KamLAND as well as by the new low energy experiments will allow us to check this possibility.

  17. Lepton mixing and the ''solar neutrino puzzle''

    International Nuclear Information System (INIS)

    Bilenky, S.M.; Pontecorvo, B.

    1977-01-01

    The results of the well known solar neutrino experiment of Davis et al. are discussed, in which the Cl-Ar method is used. The result of the experiment, a too small neutrino signal (the so-called ''solar neutrino puzzle'), has been tentatively accounted for in a number of quite exotic explanations. It appears that the explanation in terms of lepton mixing and neutrino sterility is quite attractive from the point of view of present day elementary particle physics and is much more natural than the other explanations of the ''puzzle''

  18. Solar opacities constrained by solar neutrinos and solar oscillations

    International Nuclear Information System (INIS)

    Cox, A.N.

    1989-01-01

    This review discusses the current situation for opacities at the solar center, the solar surface, and for the few million kelvin temperatures that occur below the convection zone. The solar center conditions are important because they are crucial for the neutrino production, which continues to be predicted about 4 times that observed. The main extinction effects there are free-free photon absorption in the electric fields of the hydrogen, helium and the CNO atoms, free electron scattering of photons, and the bound-free and bound-bound absorption of photons by iron atoms with two electrons in the 1s bound level. An assumption that the iron is condensed-out below the convection zone, and the opacity in the central regions is thereby reduced, results in about a 25 percent reduction in the central opacity but only a 5 percent reduction at the base of the convection zone. Furthermore, the p-mode solar oscillations are changed with this assumption, and do not fit the observed ones as well as for standard models. A discussion of the large effective opacity reduction by weakly interacting massive particles also results in poor agreement with observed p-mode oscillation frequencies. The much larger opacities for the solar surface layers from the Los Alamos Astrophysical Opacity Library instead of the widely used Cox and Tabor values show small improvements in oscillation frequency predictions, but the largest effect is in the discussion of p-mode stability. Solar oscillation frequencies can serve as an opacity experiment for the temperatures and densities, respectively, of a few million kelvin and between 0.1 and 10 g/cm 3 . Current oscillation frequency calculations indicate that possibly the Opacity Library values need an increase of typically 15 percent just at the bottom of the convection zone at 3 x 10 6 K. 41 refs., 15 figs., 1 tab

  19. LENS spectroscopy of low energy solar neutrinos

    CERN Document Server

    Schönert, S

    2001-01-01

    The LENS experiments will measure energy resolved sub-MeV solar electron-neutrinos ( nu /sub e/) in real time via inverse beta - transition populating an isomeric state in the daughter nuclei. The subsequent de-excitation provides a delayed coincidence tag which discriminates against background. A liquid scintillation detector loaded with 20 t of Yb would yield an event rate of 190 pp- and 175 /sup 7/Be neutrinos per year. Essential information on neutrino mixing and masses can be derived.

  20. 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.)

  1. Solar Neutrino Day-Night Effect

    International Nuclear Information System (INIS)

    Blennow, Mattias; Ohlsson, Tommy; Snellman, Hakan

    2005-01-01

    We summarize the results of Ref. [M. Blennow, T. Ohlsson and H. Snellman, Phys. Rev. D 69 (2004) 073006, hep-ph/0311098] in which we determine the effects of three flavor mixing on the day-night asymmetry in the flux of solar neutrinos. Analytic methods are used to determine the difference in the day and night solar electron neutrino survival probabilities and numerical methods are used to determine the effect of three flavor mixing at detectors

  2. Discrete symmetries and solar neutrino mixing

    Energy Technology Data Exchange (ETDEWEB)

    Kapetanakis, D.; Mayr, P.; Nilles, H.P. (Physik Dept., Technische Univ. Muenchen, Garching (Germany) Max-Planck-Inst. fuer Physik, Werner-Heisenberg-Inst., Muenchen (Germany))

    1992-05-21

    We study the question of resonant solar neutrino mixing in the framework of the supersymmetric extension of the standard model. Discrete symmetries that are consistent with solar neutrino mixing and proton stability are classified. In the minimal model they are shown to lead to two distinct patterns of allowed dimension-four operators. Imposing anomaly freedom, only three different discrete Z{sub N}-symmetries (with N=2, 3, 6) are found to be phenomenologically acceptable. (orig.).

  3. Discrete symmetries and solar neutrino mixing

    International Nuclear Information System (INIS)

    Kapetanakis, D.; Mayr, P.; Nilles, H.P.

    1992-01-01

    We study the question of resonant solar neutrino mixing in the framework of the supersymmetric extension of the standard model. Discrete symmetries that are consistent with solar neutrino mixing and proton stability are classified. In the minimal model they are shown to lead to two distinct patterns of allowed dimension-four operators. Imposing anomaly freedom, only three different discrete Z N -symmetries (with N=2, 3, 6) are found to be phenomenologically acceptable. (orig.)

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

    Energy Technology Data Exchange (ETDEWEB)

    Bergström, Johannes [Departament d’Estructura i Constituents de la Matèria and Institut de Ciencies del Cosmos,Universitat de Barcelona, Diagonal 647, E-08028 Barcelona (Spain); Gonzalez-Garcia, M. C. [Departament d’Estructura i Constituents de la Matèria and Institut de Ciencies del Cosmos,Universitat de Barcelona, Diagonal 647, E-08028 Barcelona (Spain); Institució Catalana de Recerca i Estudis Avançats (ICREA) (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 [Instituto de Física Teórica UAM/CSIC,Calle de Nicolás Cabrera 13-15, Universidad Autónoma de Madrid,Cantoblanco, E-28049 Madrid (Spain); Peña-Garay, Carlos [Instituto de Física Corpuscular (IFIC), CSIC and Universitat de Valencia,Calle Catedrático José Beltrán, 2, E-46090 Paterna, Valencia (Spain); Serenelli, Aldo M. [Institut de Ciencies de l’Espai (ICE-CSIC/IEEC),Campus UAB, Carrer de Can Magrans s/n, 08193 Cerdanyola del Valls (Spain); Song, Ningqiang [C.N. Yang Institute for Theoretical Physics,State University of New York at Stony Brook, Stony Brook, NY 11794-3840 (United States)

    2016-03-18

    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.

  5. Implication of the solar neutrino experiments

    International Nuclear Information System (INIS)

    Dar, A.; Nussinov, S.

    1992-01-01

    The recent results from the KAMIOKANDE II and BAKSAN solar neutrino experiments, if correct, imply that lepton flavour is not conserved. The Mikheyev-Smirnov-Wolfenstein (MSW) solution to the solar neutrino problem, which was first exposed by the HOMESTAKE Cl experiment, fully explains also these results if the electron neutrino is mixed with the muon neutrino or the tau neutrino with mixing parameters Δm 2 ≅ 10 -6 eV 2 2 and sin 2 Θ ≅ 4 x 10 -2 . This MSW solution can be tested with the new generation of solar neutrino experiments which will be able to detect both the predicted distortion of the spectrum of 8 B solar νe's and the 'missing' ν e 's that appear as ν μ 's or ν τ 's. Further evidence may be obtained from the day-night effect and from the flavour content of the neutronization burst from the birth of a neutron star in a nearby supernova. Moreover, the MSW solution combined with the seesaw mechanism for generating neutrino masses further suggests m νe ≅ 10 -8 eV, m νμ ≅ 10 -3 cV, m ντ ≅ 10eV, and sin 2 2Θ ≅ 4x10 -2 for ν μ ν τ mixing. These predictions can be tested by previously proposed neutrino oscillation experiments at accelerators and by detecting neutrinos from a nearby supernova explosion. A tau neutrino with m ντ ≅ 10 eV can account for most of the dark matter in the Universe and is a viable candidate for the hot dark matter scenario of the formation of large scale structure in the Universe. (orig.)

  6. Large Extra Dimensions, Sterile Neutrinos and Solar Neutrino Data

    International Nuclear Information System (INIS)

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

    2001-01-01

    Solar, atmospheric, and LSND neutrino oscillation results require a light sterile neutrino, ν B , which can exist in the bulk of extra dimensions. Solar ν e , confined to the brane, can oscillate in the vacuum to the zero mode of ν B and via successive Mikheyev-Smirnov-Wolfenstein transitions to Kaluza-Klein states of ν 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

  7. 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.

  8. SOLAR NEUTRINO PHYSICS: SENSITIVITY TO LIGHT DARK MATTER PARTICLES

    Energy Technology Data Exchange (ETDEWEB)

    Lopes, Ilidio [Centro Multidisciplinar de Astrofisica, Instituto Superior Tecnico, Universidade Tecnica de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa (Portugal); Silk, Joseph, E-mail: ilidio.lopes@ist.utl.pt, E-mail: ilopes@uevora.pt, E-mail: silk@astro.ox.ac.uk [Institut d' Astrophysique de Paris, UMR 7095 CNRS, Universite Pierre et Marie Curie, 98 bis Boulevard Arago, Paris 75014 (France)

    2012-06-20

    Neutrinos are produced in several neutrino nuclear reactions of the proton-proton chain and carbon-nitrogen-oxygen cycle that take place at different radii of the Sun's core. Hence, measurements of solar neutrino fluxes provide a precise determination of the local temperature. The accumulation of non-annihilating light dark matter particles (with masses between 5 GeV and 16 GeV) in the Sun produces a change in the local solar structure, namely, a decrease in the central temperature of a few percent. This variation depends on the properties of the dark matter particles, such as the mass of the particle and its spin-independent scattering cross-section on baryon-nuclei, specifically, the scattering with helium, oxygen, and nitrogen among other heavy elements. This temperature effect can be measured in almost all solar neutrino fluxes. In particular, by comparing the neutrino fluxes generated by stellar models with current observations, namely {sup 8}B neutrino fluxes, we find that non-annihilating dark matter particles with a mass smaller than 10 GeV and a spin-independent scattering cross-section with heavy baryon-nuclei larger than 3 Multiplication-Sign 10{sup -37} cm{sup -2} produce a variation in the {sup 8}B neutrino fluxes that would be in conflict with current measurements.

  9. BOREX: Solar neutrino experiment via weak neutral and charged currents in boron-11

    International Nuclear Information System (INIS)

    Kovacs, T.; Mitchell, J.W.; Raghavan, P.

    1989-01-01

    Borex, and experiment to observe solar neutrinos using boron loaded liquid scintillation techniques, is being developed for operation at the Gran Sasso underground laboratory. It aims to observe the spectrum of electron type 8 B solar neutrinos via charged current inverse β-decay of 11 B and the total flux solar neutrinos regardless of flavor by excitation of 11 B via the weak neutral current. 14 refs

  10. Neutrino-electron scattering and the choice between different MSW solutions of the solar neutrino problem

    International Nuclear Information System (INIS)

    Rosen, S.P.; Gelb, J.M.

    1989-01-01

    This paper considers the scattering of solar neutrinos by electrons as a means for distinguishing between different MSW solutions of the solar neutrino problem. In terms of the ratio R between the observed cross-section and that for pure electron-type neutrinos, some correlation between the value of R and each solution is found. A value of R ≤ 1/3 implies that the adiabatic solution is correct, while values between 1/3 and 3/5 are consistent with the large angle solution. A value close to 1/2 is also consistent with the non-adiabatic solution, and a value less than (1/6 - 1/7) implies oscillations into sterile neutrinos

  11. Update of GALLEX solar neutrino results and implications

    International Nuclear Information System (INIS)

    Kirsten, T.

    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 +2σ is required to accommodate not only pp-and pep- but also the 7 Be-neutrino induced 71 Ge-production. Contrary, the fate of 8 B-neutrinos has only little discernible effect on the GALLEX data. In conclusion, with the present errors GALLEX constitutes a 2.5 σ problem for 7 Be neutrinos within the frame of open-quotes astrophysicalclose 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

  12. Status of the Gribov-Pontecorvo Solution to the Solar Neutrino Problem

    CERN Document Server

    Berezinsky, Veniamin Sergeevich; Peña-Garay, C

    2001-01-01

    We discuss the status of the Gribov--Pontecorvo (GP) solution to the solar neutrino problem. This solution naturally appears in bimaximal neutrino mixing and reduces the solar and atmospheric neutrino problems to vacuum oscillations of three active neutrinos. The GP solution predicts an energy-independent suppression of the solar neutrino flux. It is disfavoured by the rate of the Homestake detector, but its statistical significance greatly improves, when the chlorine rate and the boron neutrino flux are slightly rescaled, and when the Super-Kamiokande neutrino spectrum is included in the analysis. Our results show that rescaling of the chlorine signal by only 10% is sufficient for the GP solution to exist, if the boron--neutrino flux is taken 10 -- 20% lower than the SSM prediction. The regions allowed for the GP solution in the parameter space are found and observational signatures of this solution are discussed.

  13. Solar neutrinos at super-Kamiokande

    International Nuclear Information System (INIS)

    Inoue, K.

    1999-01-01

    A huge ring imaging water Cherenkov detector, super-Kamiokande, has started data accumulation on April 1st, 1996 as promised. This experiment is expected to give a definite answer to the neutrino oscillation solutions of the long standing solar neutrino problem through high statistics and high precision spectrum and day/night flux measurement. Super-Kamiokande is accumulating 8 B solar neutrino data very quickly and preliminary results obtained from 374 days of data are presented here, instead of 306 days of data presented at the conference. No significant day/night variation nor seasonal variation are found. Systematic errors of energy scale are largely reduced by the LINAC calibrations at various positions. And the experiment is getting closer to the level of the systematic errors where we can definitely discuss about the spectrum distortion. Also implications of those preliminary results are discussed within two neutrino oscillation hypothesis

  14. Resonant spin-flavor precession of neutrino and the solar neutrino problem

    International Nuclear Information System (INIS)

    Akhmedov, E.Kh.; Bychuk, O.V.; AN SSSR, Moscow

    1989-01-01

    Resonant amplification of spin-flavor precession of neutrinos in solar matter is considered. Some possible consequences of the process are discussed. It is shown that resonant spin-flavor neutrino precession may account for the deficit of solar neutrinos in Davis' experiment and the anticorrelation between the rate of neutrino counting and solar activity. Experiments are considered which should make it possible to distinguish between spin-flavor neutrino precession and the Mikheyev-Smirnov-Wolfenstein effect. A new restriction on the usual spin precession of solar neutrinos is derived

  15. Solar atmospheric neutrinos and the sensitivity floor for solar dark matter annihilation searches

    Energy Technology Data Exchange (ETDEWEB)

    Argüelles, C.A. [Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge MA (United States); De Wasseige, G. [Vrije Universiteit Brussel, Pleinlaan 2, 1050 Elsene, Brussels (Belgium); Fedynitch, A. [Karlsruhe Institute of Technology, 76021 Karlsruhe (Germany); Jones, B.J.P., E-mail: caad@mit.edu, E-mail: gdewasse@vub.ac.be, E-mail: anatoli.fedynitch@desy.de, E-mail: ben.jones@uta.edu [University of Texas at Arlington, 108 Science Hall, 502 Yates St, Arlington TX (United States)

    2017-07-01

    Cosmic rays interacting in the solar atmosphere produce showers that result in a flux of high-energy neutrinos from the Sun. These form an irreducible background to indirect solar WIMP self-annihilation searches, which look for heavy dark matter particles annihilating into final states containing neutrinos in the Solar core. This background will eventually create a sensitivity floor for indirect WIMP self-annihilation searches analogous to that imposed by low-energy solar neutrino interactions for direct dark matter detection experiments. We present a new calculation of the flux of solar atmospheric neutrinos with a detailed treatment of systematic uncertainties inherent in solar atmospheric shower evolution, and we use this to derive the sensitivity floor for indirect solar WIMP annihilation analyses. We find that the floor lies less than one order of magnitude beyond the present experimental limits on spin-dependent WIMP-proton cross sections for some mass points, and that the high-energy solar atmospheric neutrino flux may be observable with running and future neutrino telescopes.

  16. Probing the nature of the neutrino: The boron solar-neutrino experiment

    International Nuclear Information System (INIS)

    Raghavan, R.S.; Pakvasa, S.

    1988-01-01

    With a welter of neutrino scenarios and uncertain solar models to be unraveled, can solar-neutrino experiments really break new ground in neutrino physics? A new solar-neutrino detector BOREX, based on the nuclide /sup 11/B, promises the tools for a definitive exploration of the nature of the neutrino and the structure of the Sun. Using double-mode detection by neutrino excitation of /sup 11/B via the neutral-weak-current- and the charged-current-mediated inverse β decay in the same target, independent measurements of the total neutrino flux regardless of flavor and the survival of electron neutrinos in solar matter and a vacuum can be made. Standard models of the Sun, and almost every proposed nonstandard model of the neutrino, can be subjected to sharp and direct tests. The development of BOREX, based on B-loaded liquid-scintillation techniques, is currently in progress

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

    International Nuclear Information System (INIS)

    Holanda, Pedro Cunha de

    2011-01-01

    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 ≡ 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: ΔN eff = 1 - 2. These facts strengthen the case of very light sterile neutrino, ν s , with Δm 0 1 2 ∼ (0.7 - 2) . 10 -5 e V 2 , which mixes weakly with the active neutrinos. The ν s mixing in the mass eigenstate ν 1 characterized by sin 2 2∝ ∼ 10 -3 can explain an absence of the upturn. The mixing of ν s in the eigenstate ν 3 with sin 2 β ∼ 0.1 leads to production of ν s via oscillations in the Universe and to additional contribution Δ N eff ∼ 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)

  18. Radiochemical Solar Neutrino Experiments - Successful and Otherwise

    International Nuclear Information System (INIS)

    Hahn, R.L.

    2008-01-01

    Over the years, several different radiochemical systems have been proposed as solar neutrino detectors. Of these, two achieved operating status and obtained important results that helped to define the current field of neutrino physics: the first solar-neutrino experiment, the Chlorine Detector ( 37 Cl) that was developed by chemist Raymond Davis and colleagues at the Homestake Mine, and the subsequent Gallium ( 71 Ga) Detectors that were operated by (a) the SAGE collaboration at the Baksan Laboratory and (b) the GALLEX/GNO collaborations at the Gran Sasso National Laboratory. These experiments have been extensively discussed in the literature and in many previous International Neutrino Conferences. In this paper, I present important updates to the results from SAGE and GALLEX/GNO. I also review the principles of the radiochemical detectors and briefly describe several different detectors that have been proposed. In light of the well-known successes that have been subsequently obtained by real-time neutrino detectors such as Kamiokande, Super-Kamiokande, SNO, and KamLAND, I do not anticipate that any new radiochemical neutrino detectors will be built. At present, only SAGE is still operating; the Chlorine and GNO radiochemical detectors have been decommissioned and dismantled

  19. Radiochemical solar neutrino experiments, 'successful and otherwise'

    International Nuclear Information System (INIS)

    Hahn, Richard L

    2008-01-01

    Over the years, several different radiochemical systems have been proposed as solar neutrino detectors. Of these, two achieved operating status and obtained important results that helped to define the current field of neutrino physics: the first solar-neutrino experiment, the Chlorine Detector ( 37 Cl) that was developed by chemist Raymond Davis and colleagues at the Homestake Mine, and the subsequent Gallium ( 71 Ga) Detectors that were operated by (a) the SAGE collaboration at the Baksan Laboratory and (b) the GALLEX/GNO collaborations at the Gran Sasso National Laboratory. These experiments have been extensively discussed in the literature and in many previous International Neutrino Conferences. In this paper, I present important updates to the results from SAGE and GALLEX/GNO. I also review the principles of the radiochemical detectors and briefly describe several different detectors that have been proposed. In light of the well-known successes that have been subsequently obtained by real-time neutrino detectors such as Kamiokande, Super-Kamiokande, SNO, and KamLAND, I do not anticipate that any new radiochemical neutrino detectors will be built. At present, only SAGE is still operating; the Chlorine and GNO radiochemical detectors have been decommissioned and dismantled.

  20. Solar neutrino results from Super-Kamiokande

    International Nuclear Information System (INIS)

    Takeuchi, Y.

    2001-01-01

    Latest Super-Kamiokande results of the solar neutrino flux, day/night results, energy spectrum measurements, and oscillation analyses are reported. The observation period spans May 31, 1996 to April 24, 2000, which corresponds to a detector live time of 1117 days. Our preliminary results indicate 1.3σ difference between day and night flux, and the energy spectrum expressed as data/(BP98 SSM) is consistent with a flat spectrum with χ 2 /D.O.F.=13.7/17. Comparing global-flux oscillation analysis and SK day and night spectra, MSW SMA region, Just-So region and 2-flavor sterile solutions are disfavored at 95% C.L. (author)

  1. Solar neutrinos and solar accretion of interstellar matter

    International Nuclear Information System (INIS)

    Newman, M.J.; Talbot, R.J. Jr.

    1976-01-01

    It is argued that if the Hoyle-Lyttleton mass accretion rate applies (Proc. Camb. Phil. Soc., Math. Phys. Sci. 35: 405 (1939)) the accretion of interstellar matter by the Sun is sufficient to enhance the surface heavy element abundances. This will also apply to other solar-type stars. The enhancement may be sufficient to allow the construction of consistent solar models with an interior heavy element abundance significantly lower than the observed surface abundance. This state of affairs lowers the predicted solar neutrino flux. It has been suggested that a similar enhancement of surface abundances might occur due to accretion of 'planetesimals' left over after formation of the solar system, and both processes may occur, thereby increasing the effect. The simple accretion model of Hoyle and Lyttleton is discussed mathematically. A crucial question to be answered by future research, however, is whether or not accretion on to the solar surface actually occurs. One of the most obvious obstacles is the outward flowing solar wind, and this is discussed. It appears that the outward flow can be reversed to an inward flow for certain interstellar cloud densities. (U.K.)

  2. A liquid scintillator detector for the solar neutrino

    Energy Technology Data Exchange (ETDEWEB)

    Ranucci, G [Lab. Nazionali del Gran Sasso, Assergi (Italy) Massachusetts Inst. of Technology, Cambridge, MA (United States) Joint Inst. for Nuclear Research, Dubna (USSR) Technical Univ. of Munich, Garching (Germany) Physics Dept., Univ. Genova (Italy) INFN, Genova (Italy) Univ. Hawaii, Honolulu, HI (United States) CCR Euratom, Ispra (Italy) Physics Dept., Univ. Milano (Italy) INFN, Milano (Italy) AT and T Bell Lab., Murray Hill, NJ (United States) Physics Dept., Univ. Pavia (Italy) INFN, Pavia (Italy) Physics Dept., Univ. Perugia (Italy) INFN, Perugia (Italy) Drexel Univ., Philadelphia, PA (United States) Charles Univ., Prague (Czechoslovakia) Czech Technical Univ., Prague (Czechoslovakia); Borex Collaboration

    1992-05-01

    Results of the three solar neutrino experiments presently running strongly suggest new neutrino physics scenarios to explain the discrepancy between the expected and measured neutrino flux. New experiments are needed to decide among the several theoretical explanations for this that has become known as the solar neutrino problem. This paper describes the unique features of the proposed low energy solar neutrino detector Borexino, that fully exploiting the powerful handless of liquid scintillation spectroscopy on large scale, will probe emerging suggestions on scenarios invoking neutrino mass mixing and magnetic moment. (orig.).

  3. Solar neutrinos and the Mikheyev-Smirnov-Wolfenstein theory

    International Nuclear Information System (INIS)

    Bethe, H.A.; Bahcall, J.N.

    1991-01-01

    The observation of solar neutrinos by Kamiokande shows that the solar-neutrino problem cannot be solved by changing the solar model. In combination with the observations with a chlorine detector, it makes the nonadiabatic form of the Mikheyev-Smirnov-Wolfenstein theory most likely, and determines Δm 2 sin 2 θ=1.0x10 -8 eV 2 . Probably all neutrinos go through the resonance in the Sun, those from 8 B nonadiabatically, all others adiabatically. The latter emerge from the Sun in the higher-mass eigenstate ν 2 and have a probability sin 2 θ to be detected as ν e . The gallium experiments, when done with sufficient accuracy, will be able to determine Δm 2 =m 2 (ν μ )-m 2 (ν e ) within fairly close limits. If the day-night effect can be measured, it will further constrain these limits. The small value of Δm 2 sin 2 θ explains why the oscillation from ν e to ν μ has not been observed in the laboratory. From existing experiments, the temperature at the center of the Sun can be determined to be within about 6% of that derived from the standard solar model; future neutrino experiments may determine it to within 1%

  4. Solar neutrino results and present status

    International Nuclear Information System (INIS)

    Gorbachev, V.V.; Abdurashitov, J.N.; Gavrin, V.N.; Girin, S.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.; Vermul, V.M.; Yants, V.E.; Zatsepin, G.T.; Bowles, T.J.; Teasdale, W.A.; Cherry, M.L.; Cleveland, B.T.; Elliott, S.R.

    2002-01-01

    The solar neutrino capture rate measured by the Russian-American Gallium Experiment on a metallic gallium target SAGE during the time from January 1990 through December 2000 is 77.0 +6.2 -6.2 +3.5 -3.0 SNU, where the uncertainties are statistical and systematic, respectively. The experimental procedures and data analysis are presented

  5. Helioseismic and neutrino data-driven reconstruction of solar properties

    Science.gov (United States)

    Song, Ningqiang; Gonzalez-Garcia, M. C.; Villante, Francesco L.; Vinyoles, Nuria; Serenelli, Aldo

    2018-06-01

    In this work, we use Bayesian inference to quantitatively reconstruct the solar properties most relevant to the solar composition problem using as inputs the information provided by helioseismic and solar neutrino data. In particular, we use a Gaussian process to model the functional shape of the opacity uncertainty to gain flexibility and become as free as possible from prejudice in this regard. With these tools we first readdress the statistical significance of the solar composition problem. Furthermore, starting from a composition unbiased set of standard solar models (SSMs) we are able to statistically select those with solar chemical composition and other solar inputs which better describe the helioseismic and neutrino observations. In particular, we are able to reconstruct the solar opacity profile in a data-driven fashion, independently of any reference opacity tables, obtaining a 4 per cent uncertainty at the base of the convective envelope and 0.8 per cent at the solar core. When systematic uncertainties are included, results are 7.5 per cent and 2 per cent, respectively. In addition, we find that the values of most of the other inputs of the SSMs required to better describe the helioseismic and neutrino data are in good agreement with those adopted as the standard priors, with the exception of the astrophysical factor S11 and the microscopic diffusion rates, for which data suggests a 1 per cent and 30 per cent reduction, respectively. As an output of the study we derive the corresponding data-driven predictions for the solar neutrino fluxes.

  6. Solar neutrinos: proposal for a new test

    International Nuclear Information System (INIS)

    Freedman, M.S.; Stevens, C.M.; Horivitz, E.P.; Fuchs, L.H.; Lerner, J.L.; Goodman, L.S.; Childs, W.J.; Hessler, J.

    1976-01-01

    The predicted flux on the earth of solar neutrinos has eluded detection, confounding current ideas of solar energy production by nuclear fusion. The dominant low-energy component of that flux can be detected by mass-spectrometric assay of the induced tiny concentration of 1.6 x 10 7 year lead-205 in old thallium minerals. Comments are solicited from those in all relevant disciplines

  7. SNO results and neutrino magnetic moment solution to the solar ...

    Indian Academy of Sciences (India)

    that the solar neutrino deficit is due to the interaction of neutrino transition magnetic moment with the solar magnetic ... Another new feature in the analysis is that for the global analysis, we have replaced the spectrum by its centroid. ... rise to mean potentials Va for neutrinos which are proportional to the number density of.

  8. GRAN SASSO/GRENOBLE: Artificial neutrino source confirms solar neutrino result

    International Nuclear Information System (INIS)

    Anon.

    1995-01-01

    In 1992, the Gallex experiment announced the first observation of the neutrinos produced in the primary proton-proton fusion reaction in the core of the Sun, reaction at the origin of the energy production by our star (September 1992, page 1). The Gallex team stressed that the observed neutrino flux was only about two-thirds of the predicted level, confirming the deficit observed by the two pioneering experiments, Ray Davis' chlorine-based detector in the USA and the Kamiokande study in Japan (which are only sensitive to neutrinos from subsidiary solar fusion processes). This deficit demands explanation, and could considerably modify our understanding of how stars shine and/or of neutrino physics. But before drawing conclusions, the Gallex result had to be checked. Gallex, installed in the Italian Gran Sasso underground Laboratory, is a radiochemical experiment using neutrino interactions to transform gallium-71 into germanium-71. The latter is radioactive and decays with a half-life of 11.4 days. Counting the germanium-71 atoms extracted from the target tank measures the neutrino flux to which the detector is exposed. Neutrinos are famous for their reluctance to interact. 65 billion per square centimetre per second on the surface of the Earth produce only one germanium-71 atom in the Gallex target containing 30 tons of gallium. This is at the limit of homeopathy (extracting few atoms of germanium-71 from a solution containing 10 30 atoms) and needs careful checking. Since it is not possible to switch off the Sun, the only recourse was to build an artificial neutrino source more powerful than the Sun as a benchmark. This was done last summer. Last May, 36 kilograms of chromium grains were placed in the Siloe reactor of the French Commissariat à l'énergie atomique, Grenoble. The chromium had been previously enriched to 40% chromium-50 by the Kurchatov Institute in Moscow (natural chromium contains only 4.5% chromium-50). A dedicated core was built for

  9. Neutrino oscillations in the Earth suggest a terrestrial test of solution to solar neutrino problem

    International Nuclear Information System (INIS)

    Dar, A.; Mann, A.; Technicon-Israel Inst. of Tech., Haifa. Space Research Inst.)

    1987-01-01

    The verification of the Mikheyev-Smirnov-Wolfenstein (MSW) solution of the solar neutrino problem is discussed. One verification experiment concerns the detection of sizeable oscillations of atmospheric neutrinos in the earth, which can be detected with the massive underground proton decay detectors. Diurnal and seasonal modulations of the solar neutrino flux can perhaps be detected by the radiochemical Cl and Ga detectors. Moreover, neutrino oscillations in the Earth may modify the values of the oscillation parameters which can solve the solar neutrino problem and help determine their values. (UK)

  10. Three neutrino flavors: Oscillations, mixing, and the solar-neutrino problem

    International Nuclear Information System (INIS)

    Pantaleone, J.

    1991-01-01

    An analytical, quantitative description of solar-neutrino propagation is presented which includes three flavors, matter dependence, and long-wavelength effects. Using the derived expression for the electron-neutrino survival probability, it is demonstrated that mixing is possible between the two-flavor Mikheyev-Smirnov-Wolfenstein and two-flavor long-wavelength solutions to the solar-neutrino problem. However, adiabatic conversion of a neutrino mass eigenstate tends to suppress all subsequent long-wavelength effects such as ''seasonal'' variations in the solar-neutrino flux

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

    International Nuclear Information System (INIS)

    Maneschg, Werner

    2011-01-01

    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 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 11 C. Its rate is ∝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 11 C is mostly produced under the release of a free neutron, 11 C can be tagged with a threefold coincidence (TFC) consisting of the muon signal, the neutron capture and the subsequent 11 C decay. By optimizing the TFC method and other rejection techniques, a 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 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 ∝5 MBq 228 Th source was produced and an external calibration was carried out for the first time. The obtained calibration data and the achieved 11 C rejection efficiency will allow for the direct detection of solar pep and possibly also CNO neutrinos with Borexino. (orig.)

  12. Report of the Solar and Atmospheric Neutrino Working Group

    International Nuclear Information System (INIS)

    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.

    2004-01-01

    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 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 ν e , which also permits sensitive tests for sterile neutrinos. The pp experiment will also permit a significantly improved determination of θ 12 and, together with other solar neutrino measurements, either a measurement of θ 13 or a constraint a factor of two lower than existing bounds. In combination with the essential pre-requisite experiments that will measure the 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 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 large scale water Cerenkov detector, or a

  13. First direct detection of solar pp neutrinos by Borexino

    Energy Technology Data Exchange (ETDEWEB)

    Maneschg, Werner [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Collaboration: Werner Maneschg on behalf of the Borexino collaboration

    2015-07-01

    According to the Standard Solar Model (SSM) the radiative energy of our Sun is produced by a series of nuclear reactions that convert hydrogen into helium. In 99% of cases these processes are supposed to start with a fusion of two protons and the emission of a positron and a low-energy neutrino. These so-called pp neutrinos vastly outnumber those emitted in other sub-reactions, but only the large volume organic liquid scintillator detector Borexino has recently succeeded to perform a spectroscopic and direct measurement of them. The present talk reviews the procedure adopted by the Borexino collaboration to detect pp neutrinos. The key requirements, i.e. unprecedented radiopurity levels at low energies and a precise spectral description of the main background arising from 14C decays, and their fulfillment are discussed. The measured pp neutrino flux is then compared with the predictions of the SSM including neutrino oscillation mechanisms, and with the solar luminosity constraint deduced from photospheric observations.

  14. 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...

  15. The status of the solar neutrino problem and the Russian-American gallium experiment (SAGE)

    International Nuclear Information System (INIS)

    Bowles, T.J.

    1994-01-01

    Perhaps the most outstanding discrepancy between prediction and measurements in current particle physics comes from the solar neutrino problem, in which a large deficit of high-energy solar neutrinos is observed. Many Nonstandard Solar Models have been invoked to try to reduce the predicted flux, but all have run into problems in trying to reproduce other measured parameters (e.g., the luminosity) of the Sun. Other explanations involving new physics such as neutrino decay and neutrino oscillations, etc. have also been proffered. Again, most of these explanations have been ruled out by either laboratory or astrophysical measurements. It appears that perhaps the most likely particle physics solution is that of matter enhanced neutrino oscillation, the Mikheyev-Smirnov-Wolfenstein (MSW) oscillations. Two new radiochemical gallium experiments, which have a low enough threshold to be sensitive to the dominant flux of low-energy p-p neutrinos, now also report a deficit and also favor a particle physics solution

  16. Detection of solar neutrinos with a torsion balance with sapphire crystal

    Science.gov (United States)

    Cruceru, M.; Nicolescu, G.

    2018-01-01

    The solar neutrinos (antineutrinos) are detected with a dedicated torsion balance in the case when they interact coherently on stiff crystals (sapphire with high Debye temperature ∼1000K and lead with ∼100K Debye temperature). The balance consists in two equal masses of lead and sapphire, of 25g. An autocollimator coupled to this balance measures small rotation angles of the balance. The force with which neutrino flux interacts with these crystals is between 10-5 dyn and 10-8 dyn, comparable with that reported in Weber’s experiments [1]. A diurnal effect is observed for solar neutrinos due to the rotation of the Earth around its own axes. The solar neutrino flux obtained at the site of our experiment is ∼3.8*1010neutrinos/cm2*s [2]. Experimental data for neutrinos signals from this high sensitivity torsion balance are presented and commented [3].

  17. Resonant amplification of neutrino spin rotation in matter and the solar-neutrino problem

    International Nuclear Information System (INIS)

    Akhmedov, E.Kh.

    1988-01-01

    It is shown that in the presence of matter there can occur resonant amplification of the flavor-changing neutrino spin rotation in transverse magnetic fields, which is roughly analogous to the Mikheyev-Smirnov-Wolfenstein effect in neutrino oscillations. Possible consequences for solar neutrinos are briefly discussed. (orig.)

  18. The molybdenum-technetium solar neutrino experiment

    International Nuclear Information System (INIS)

    Schroeder, N.C.; Wolfsberg, K.; Rokop, D.J.

    1991-01-01

    The authors are attempting to measure the time-averaged 8 B solar-neutrino flux over 10 Myr by measuring 98 Tc produced through the 98 Mo( nu ,e - ) reaction in a deeply buried molybdenum deposit. This will test the prediction of periodic mixing of the Sun's core over long time intervals. To separate technetium from 10,000-ton quantities of Henderson ore, the authors have taken advantage of the commercial processing of molybdenite. Technetium, volatilized during roasting of molybdenite to MoO 3 , was scrubbed from the gas stream and collected on anion exchange columns. After sample reduction and chemical separation and purification they measured technetium, as TcO 4 - , using negative thermal ionization mass spectrometry. Measurement of 99 Tc in spiked and 98 Tc in unspiked fractions from one sample gives an apparent solar neutrino production rate of 95.8 SNU. However, roaster memory probably invalidates this result

  19. The Russian-American Gallium solar neutrino Experiment

    International Nuclear Information System (INIS)

    Elliott, S.R.; Abdurashitov, J.N.

    1995-01-01

    The Russian-American Gallium solar neutrino Experiment (SAGE) is described. The solar neutrino flux measured by 31 extractions through October, 1993 is presented. The result of 69 ± 10 -7 +5 SNU is to be compared with a standard solar model prediction of 132 SNU. The status of a 51 Cr neutrino source irradiation to test the overall operation of the experiment is also presented

  20. What can four solar neutrino experiments tell us about the magnetic moment solution to the solar neutrino problem?

    International Nuclear Information System (INIS)

    Pulido, J.

    1993-01-01

    The results reported by the four solar neutrino experiments (Homestake, Kamiokande, SAGE, Gallex) are analyzed from the point of view of the magnetic moment solution to the solar neutrino problem. The neutrino deficit reported by the gallium experiments (SAGE, Gallex) is apparently not as large as the one reported by Homestake and Kamiokande, a phenomenon suggesting a greater suppression in the large energy solar neutrino sector but also consistent with a uniform suppression for all neutrinos. Both uniform and nonuniform suppressions are examined for three different variants of the solar magnetic field and the possible parameter ranges for Δ 2 m 21 and μ ν are investigated. Massless neutrinos are not excluded and in all cases Δ 2 m 21 -5 eV 2 . The anticorrelation of the neutrino flux with sunspot activity is possible in any of the experiments but is in no way implied by a sizable magnetic moment and magnetic field

  1. New neutrino physics and the altered shapes of solar neutrino spectra

    Science.gov (United States)

    Lopes, Ilídio

    2017-01-01

    Neutrinos coming from the Sun's core have been measured with high precision, and fundamental neutrino oscillation parameters have been determined with good accuracy. In this work, we estimate the impact that a new neutrino physics model, the so-called generalized Mikheyev-Smirnov-Wolfenstein (MSW) oscillation mechanism, has on the shape of some of leading solar neutrino spectra, some of which will be partially tested by the next generation of solar neutrino experiments. In these calculations, we use a high-precision standard solar model in good agreement with helioseismology data. We found that the neutrino spectra of the different solar nuclear reactions of the pp chains and carbon-nitrogen-oxygen cycle have quite distinct sensitivities to the new neutrino physics. The He P and 8B neutrino spectra are the ones in which their shapes are more affected when neutrinos interact with quarks in addition to electrons. The shapes of the 15O and 17F neutrino spectra are also modified, although in these cases the impact is much smaller. Finally, the impact in the shapes of the P P and 13N neutrino spectra is practically negligible.

  2. 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.

  3. SOLAR NEUTRINO PHYSICS OSCILLATIONS: SENSITIVITY TO THE ELECTRONIC DENSITY IN THE SUN'S CORE

    Energy Technology Data Exchange (ETDEWEB)

    Lopes, Ilidio [Centro Multidisciplinar de Astrofisica, Instituto Superior Tecnico, Universidade Tecnica de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa (Portugal); Turck-Chieze, Sylvaine, E-mail: ilidio.lopes@ist.utl.pt, E-mail: ilopes@uevora.pt, E-mail: sylvaine.turck-chieze@cea.fr [CEA/IRFU/Service d' Astrophysique, CE Saclay, F-91191 Gif sur Yvette (France)

    2013-03-01

    Solar neutrinos coming from different nuclear reactions are now detected with high statistics. Consequently, an accurate spectroscopic analysis of the neutrino fluxes arriving on Earth's detectors becomes available, in the context of neutrino oscillations. In this work, we explore the possibility of using this information to infer the radial profile of the electronic density in the solar core. So, we discuss the constraints on the Sun's density and chemical composition that can be determined from solar neutrino observations. This approach constitutes an independent and alternative diagnostic to the helioseismic investigations already done. The direct inversion method, which we propose to obtain the radial solar electronic density profile, is almost independent of the solar model.

  4. Search for correlation of neutrino events with solar flares in Kamiokande

    International Nuclear Information System (INIS)

    Hirata, K.S.; Kajita, T.; Kifune, T.

    1988-10-01

    A search has been made for a correlation between large solar flares and neutrino events observed in Kamiokande for the period of July 1983 - July 1988. No significant neutrino signal was found at the time of a solar flare, giving a limit on the time integrated 'solar-flare' ν e flux 7 (2.5 x 10 9 )/cm 2 per flare at 90 % confidence level, for E ν = 100 (50) MeV. These limits are 2000 (60) times smaller than the value required for neutrinos with those energies to account for the excess of signal in the 37 Cl solar neutrino experiment at some of the corresponding solar flare times. (author)

  5. Neutrino burst from SN1987A and the solar-neutrino puzzle

    International Nuclear Information System (INIS)

    Arafune, J.; Fukugita, M.; Yanagida, T.; Yoshimura, M.

    1987-01-01

    The prompt ν/sub e/ signal from the supernova explosion in the Large Magellanic Cloud presumably detected by Kamiokande II does not necessarily mean that the Mikheyev-Smirnov-Wolfenstein effect on the solar-neutrino flux is not operative. The electron neutrino, once rotated to a different-flavor neutrino in the progenitor star, can come back via the matter-oscillation effect in the Earth, or a residual ν/sub e/ flux from the progenitor can directly hit the detector, saving the Mikheyev-Smirnov-Wolfenstein explanation of the solar-neutrino problem for a range of mixing parameters

  6. Neutrinos

    CERN Multimedia

    CERN. Geneva

    2004-01-01

    The Standard Model predicts that the neutrinos are massless and do not mix. Generic extensions of the Standard Model predict that neutrinos are massive (but, very likely, much lighter than the charged fermions). Therefore, the search for neutrino masses and mixing tests the Standard Model and probes new phasics. Measurements of various features of the fluxes of atmospheric, solar and, more recently, reactor neutrinos have provided evidence for neutrino oscillations and therefore for neutrino masses and mixing. These results have significant theoretical implications: new physics exists, and its scale can be estimated. There are interesting lessons for grand unified theories and for models of extra dimensions. The measured neutrino flavor parameters pose a challenge to flavor models.

  7. The solar neutrinos epopee; L'epopee des neutrinos solaires

    Energy Technology Data Exchange (ETDEWEB)

    Lasserre, Th. [CEA Saclay, Dept. d' Astrophysique, de Physique des Particules, de Physique Nucleaire et de l' Instrumentation Associee, Service de Physique des Particules, 91- Gif sur Yvette (France)

    2003-06-01

    The 2002 year has been fruitful for the neutrino physics. First, the Sudbury Neutrino Observatory (SNO) experiment has shown that the electron neutrinos {nu}{sub e} emitted by the sun are converted into muon neutrinos ({nu}{sub {mu}}) and tau neutrinos ({nu}{sub {tau}}), thus closing the 30 years old problem of solar neutrinos deficit. This discovery validates the model of nuclear energy production inside the sun but it shakes the theory describing the weak interactions between the fundamental constituents of matter. This theory considers the neutrinos (and the photons) as massless particles, while the taste conversion phenomenon necessarily implies that neutrinos have a mass. In October 2000, the Universe exploration by the cosmic neutrinos is jointly recognized by R. Davis (USA) and M. Koshiba (Japan) who received the Nobel price of physics. Finally, in December 2000, the KamLAND experiment quantitatively demonstrated the neutrinos metamorphosis by detecting a deficit in the flux of electron antineutrinos coming from the surrounding Japanese nuclear reactors. This digest article describes step by step the epopee of solar neutrinos and shows how several generations of physicists have resolved one of the mystery of modern physics. (J.S.)

  8. 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.

  9. Variations of the core luminosity and solar neutrino fluxes

    Science.gov (United States)

    Grandpierre, Attila

    The aim of the present work is to analyze the geological and astrophysical data as well as presenting theoretical considerations indicating the presence of dynamic processes present in the solar core. The dynamic solar model (DSM) is suggested to take into account the presence of cyclic variations in the temperature of the solar core. Comparing the results of calculations of the CO2 content, albedo and solar evolutionary luminosity changes with the empirically determined global earthly temperatures, and taking into account climatic models, I determined the relation between the earthly temperature and solar luminosity. These results indicate to the observed maximum of 10o change on the global terrestrial surface temperature a related solar luminosity change around 4-5 % on a ten million years timescale, which is the timescale of heat diffusion from the solar core to the surface. The related solar core temperature changes are around 1 % only. At the same time, the cyclic luminosity changes of the solar core are shielded effectively by the outer zones since the radiation diffusion takes more than 105 years to reach the solar surface. The measurements of the solar neutrino fluxes with Kamiokande 1987-1995 showed variations higher than 40 % around the average, at the Super-Kamiokande the size of the apparent scatter decreased to 13 %. This latter scatter, if would be related completely to stochastic variations of the central temperature, would indicate a smaller than 1 % change. Fourier and wavelet analysis of the solar neutrino fluxes indicate only a marginally significant period around 200 days (Haubold, 1998). Helioseismic measurements are known to be very constraining. Actually, Castellani et al. (1999) remarked that the different solar models lead to slightly different sound speeds, and the different methods of regularization yield slightly different sound speeds, too. Therefore, they doubled the found parameter variations, and were really conservative assuming

  10. 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.)

  11. Solar neutrino and 51Cr results from SAGE

    International Nuclear Information System (INIS)

    Gavrin, V.N.; Abdurashitov, J.N.; Girin, S.V.

    1997-01-01

    The Russian-American solar neutrino Experiment (SAGE) has carried out measurements of the capture rate of solar neutrinos on metallic gallium in a radiochemical experiment at the Baksan Neutrino Observatory during the period January 1990 to December 1994. The measured capture rate on 71 Ga is 72+12/-10 (stat) +5/-7 (syst) SNU. This represents only 53-59 % of the predicted Standard Solar Model (SSM) rates. Taken together with the measurements of the other solar neutrino experiments, this deficit would appear to be best interpreted as due to Mikheyev-Smirnov-Wolfenstein neutrino oscillations. A measurement of the production rate of 71 Ge by an intense 51 Cr source to test the overall operation of the experiment showed the extraction efficiency was 0.95 ± 0.11 (stat) +0.05/-0.08 (syst), indicating that the experiment is operating as expected. (orig.)

  12. Neutrinoless double beta decay and the solar neutrino problem

    International Nuclear Information System (INIS)

    Petcov, S.T.; Smirnov, A.Yu.

    1993-10-01

    The MSW or vacuum oscillation solution of the solar neutrino problem can be reconciled with possible existence of the (ββ) oν decay with a half-line corresponding to an effective Majorana mass of the electron neutrino modul m ee approx. (0.1 - 1.0) eV. The phenomenological consequences of such a possibility are analyzed and the implications for the mechanisms of neutrino mass generation are considered. (author). 31 refs, 2 figs

  13. Seasonal variations of solar neutrino rates in lithium detector

    OpenAIRE

    Kopylov, Anatoly; Petukhov, Valery

    2002-01-01

    The presence of two monochromatic lines of approximately equal intensity: $^{7}$Be- and pep-neutrinos in the sensitivity plot of lithium detector makes the pattern of the seasonal variations of the effect from solar neutrinos very characteristic in case if the long-wave vacuum oscillations are realized. This can give the very high accuracy in the measurement of the parameters of neutrino oscillations especially if combined with the results obtained by the detector sensitive mainly to $^{7}$Be...

  14. Observational investigation of the solar oblateness

    International Nuclear Information System (INIS)

    Stebbins, R.T.

    1975-01-01

    The solar oblateness provides important information for solar physics and experimental relativity. After the solar neutrino flux, the sun's shape is the most revealing probe of the solar interior. Rapidly rotating interiors suggested to explain the solar neutrino paradox produce sizeable oblatenesses. Certain types of surface phenomena can also be investigated with precision diameter measurements. The relativistic advance of Mercury's perihelion has long been the principal experimental support for Einstein's theory of general relativity. Recent measurements of the solar oblateness have suggested that the relativistic advance is smaller than originally thought due to a contribution from a solar mass quadrupole moment. This interpretation of the perihelion advance would shift the experimental support to the scalar-tensor theory of gravitation. A debate over the interpretation of the oblateness measurements has resulted. In light of these circumstances, solar oblateness observations have been attempted. Improved experimental techniques have been devised, including a daytime astrometric telescope and an explicit definition of the sun's edge. Observations reveal a time varying excess equatorial brightness, that is, a variation in the limb darkening function between equator and pole, which would preclude accurate interpretation of previous solar oblateness measurements. This vindicates the alternate interpretations of other solar oblateness measurements. From these results, it can be concluded that the Mercury perihelion evidence firmly supports Einstein's General Theory of Relativity, the solar interiors cannot be rotating fast enough to account for the low solar neutrino flux, and a time varying excess equatorial brightness exists

  15. Robust signatures of solar neutrino oscillation solutions

    CERN Document Server

    Bahcall, J N; Peña-Garay, C; Bahcall, John N.; Peña-Garay, Carlos

    2002-01-01

    With the goal of identifying signatures that select specific neutrino oscillation parameters, we test the robustness of global oscillation solutions that fit all the available solar and reactor experimental data. We use three global analysis strategies previously applied by different authors and also determine the sensitivity of the oscillation solutions to the critical nuclear fusion cross section, S_{17}(0), for the production of 8B. The neutral current to charged current ratio for SNO is predicted to be 3.5 +- 0.6 (1 sigma) for the favored LMA, LOW, and VAC solutions, which is separated from the no-oscillation value of 1.0 by much more than the expected experimental error. The predicted range of the day-night difference in charged current rates is between 0% and 21% (3 sigma) and is to be strongly correlated with the day-night effect for neutrino-electron scattering. A measurement by SNO of either a NC to CC ratio > 3.3 or a day-night difference > 10%, would favor a small region of the currently allowed LM...

  16. Theoretical introduction to the 37Cl solar neutrino experiment

    International Nuclear Information System (INIS)

    Bahcall, J.N.

    1978-01-01

    A theoretical introduction is given to the chlorine 37 solar neutrino experiment. From the definition of an SNU as 10 -36 captures per target atom per second the discussion proceeds to stellar evolution, the neutrino absorption cross sections, nuclear reactions, and lastly the implications for astronomy and for physics of the 37 Cl experiment

  17. Yet another possible explanation of the solar-neutrino puzzle

    International Nuclear Information System (INIS)

    Kolb, E.W.; Turner, M.S.; Walker, T.P.

    1986-01-01

    Mikheyev and Smirnov have shown that the interactions of neutrinos with matter can result in the conversion of electron neutrinos produced in the center of the sun to muon neutrinos. Bethe has exploited this and has pointed out that the solar-neutrino puzzle can be resolved if the mass difference squared of the two neutrinos is m 2 2 -m 2 1 approx.=6x10 -5 eV 2 , and the mixing angle satisfies sin THETAsub(v)>0.0065. We discuss a qualitatively different solution to the solar-neutrino puzzle which requires 1.0x10 -8 2 2 -m 2 1 )(sin 2 2THETAsub(v)/cos2THETAsub(v)) -8 eV 2 . Our solutions result in a much smaller flux of neutrinos from the p-p process than predicted by standard solar models, while Bethe's solution results in a flux of neutrinos from the p-p process that is about the same as standard solar models. (orig.)

  18. Yet another possible explanation of the solar-neutrino puzzle

    International Nuclear Information System (INIS)

    Kolb, E.W.; Turner, M.S.; Walker, T.P.

    1986-04-01

    Mikheyev and Smirnov have shown that the interactions of neutrinos with matter can result in the conversion of electron neutrinos produced in the center of the sun to muon neutrinos. Bethe has exploited this and has pointed out that the solar-neutrino puzzle can be resolved if the mass difference squared of the two neutrinos is m 2 2 - m 1 2 approx. = 6 x 10 -5 eV 2 , and the mixing angle satisfies sin theta/sub v/ > 0.0065. We discuss a qualitatively different solution to the solar-neutrino puzzle which requires 1.0 x 10 -8 2 2 - m 1 2 ) (sin 2 2theta/sub v//cos 2theta/sub v/) -8 eV 2 . Our solutions result in a much smaller flux of neutrinos from the p - p process than predicted by standard solar models, while Bethe's solution results in a flux of neutrinos from the p - process that is about the same as standard solar models

  19. The Baksan Neutrino Observatory Soviet-American Gallium Solar Neutrino Experiment

    International Nuclear Information System (INIS)

    Abazov, A.I.; Abdurashitov, D.N.; Anosov, O.V.

    1988-01-01

    A radiochemical 71 Ga- 71 Ge experiment to determine the integral flux of neutrinos from the sun is currently under preparation at the Baksan Neutrino Observatory in the USSR. Measurements are scheduled to commence by late 1988 with 30 tonnes of metallic gallium. A fractional statistical accuracy of 18% is expected to be obtained after one year of operation if the solar signal obtained after one year of operation if the solar signal is 70 SNU, the flux expected from p-p neutrinos alone. While initial measurements are in progress, 30 additional tonnes of gallium will be installed in order to perform the full experiment with a 60-tonne target. 28 refs

  20. Solar neutrinos as a probe of dark matter-neutrino interactions

    Energy Technology Data Exchange (ETDEWEB)

    Capozzi, Francesco; Vecchi, Luca [Dipartimento di Fisica e Astronomia, Università di Padova, via Marzolo 8, I-35131 Padova (Italy); Shoemaker, Ian M., E-mail: capozzi.12@osu.edu, E-mail: ian.shoemaker@usd.edu, E-mail: vecchi@infn.pd.it [Department of Physics, University of South Dakota, Vermillion, SD 57069 (United States)

    2017-07-01

    Sterile neutrinos at the eV scale have long been studied in the context of anomalies in short baseline neutrino experiments. Their cosmology can be made compatible with our understanding of the early Universe provided the sterile neutrino sector enjoys a nontrivial dynamics with exotic interactions, possibly providing a link to the Dark Matter (DM) puzzle. Interactions between DM and neutrinos have also been proposed to address the long-standing 'missing satellites' problem in the field of large scale structure formation. Motivated by these considerations, in this paper we discuss realistic scenarios with light steriles coupled to DM . We point out that within this framework active neutrinos acquire an effective coupling to DM that manifests itself as a new matter potential in the propagation within a medium of asymmetric DM . Assuming that at least a small fraction of asymmetric DM has been captured by the Sun, we show that a sizable region of the parameter space of these scenarios can be probed by solar neutrino experiments, especially in the regime of small couplings and light mediators where all other probes become inefficient. In the latter regime these scenarios behave as familiar 3+1 models in all channels except for solar data, where a Solar Dark MSW effect takes place. Solar Dark MSW is characterized by modifications of the most energetic {sup 8}B and CNO neutrinos, whereas the other fluxes remain largely unaffected.

  1. Proceedings of the first workshop on solar neutrino detection

    International Nuclear Information System (INIS)

    Sakuda, Makoto; Suzuki, Y.

    1986-12-01

    The purpose of the workshop was to review this vital field of the solar neutrino physics and to search for new techniques for next generation detectors to cover full range of the solar neutrino spectrum. Reviews of the solar model, the matter oscillation and experimental status were given. Discussions were also focused on a radio chemical measurement and indium detectors. Progress reports of scintillation fibers and indium-loaded scintillators were presented. Possible new detectors to use low temperature techniques were also reported. Progress reports from the Kamioka experiment, the only one from the real world, covered their search for the solar neutrinos and the effect of the matter oscillation of atomospheric neutrinos. (author)

  2. Neutrino fluxes produced by high energy solar flare particles

    International Nuclear Information System (INIS)

    Kolomeets, E.V.; Shmonin, V.L.

    1975-01-01

    In this work the calculated differential energy spectra of neutrinos poduced by high energy protons accelerated during 'small' solar flares are presented. The muon flux produced by neutrino interactions with the matter at large depths under the ground is calculated. The obtained flux of muons for the total number of solar flare accelerated protons of 10 28 - 10 32 is within 10 9 - 10 13 particles/cm 2 X s x ster. (orig.) [de

  3. Feasibility studies of the geochemical Ti-205 solar neutrino experiment

    CERN Document Server

    Neumaier, S; Nolte, E; Morinaga, H

    1991-01-01

    New investigations on the signal to background ratio of the geochemical 205Tl( v., e-)205Pb solar neutrino experiment are presented. The neutrino capture rate of 205Tl and a possible reduction of the neutrino signal due to neutrino oscillations in matter are discussed. The contributions of natural radioactivity, stopped negative muons and fast muons to the background of 205Pb are estimated. The production of radioisotopes in the lead region induced by cosmic ray muons was studied at the high energy muon beam (M2) of CERN with 120, 200 and 280 GeV muons. The background contribution of cosmic ray muons is found to be significantly higher than expected by former estimations and restricts the feasibility of the 205Tl solar neutrino experiment.

  4. Observation of muon-electron pairs in neutrino reactions

    International Nuclear Information System (INIS)

    Hoffmann, D.

    1980-05-01

    The present thesis describes the observation of muon-electron pairs in neutrino reactions. This experiment was performed using an optical multiplate spark chamber in the broad band neutrino beam of the CERN proton synchrotron. (orig.) [de

  5. Adiabatic resonant oscillations of solar neutrinos in three generations

    International Nuclear Information System (INIS)

    Kim, C.W.; Sze, W.K.

    1987-01-01

    The Mikheyev-Smirnov-Wolfenstein model of resonant solar-neutrino oscillations is discussed for three generations of leptons. Assuming adiabatic transitions, bounds for the μ- and e-neutrinos mass-squared difference Δ/sub 21,0/ are obtained as a function of the e-μ mixing angle theta 1 . The allowed region in the Δ/sub 21,0/-theta 1 plot that would solve the solar-neutrino problem is shown to be substantially larger than that of the two-generation case. In particular, the difference between the two- and three-generation cases becomes significant for theta 1 larger than --20 0

  6. Microscopic calculation of neutrino capture rates in /sup 69,71/Ga and the detection of solar and galactic neutrinos

    International Nuclear Information System (INIS)

    Grotz, K.; Klapdor, H.V.; Metzinger, J.

    1986-01-01

    Calculations of the neutrino capture cross sections for /sup 69,71/Ga based on a microscopic treatment of the Gamow-Teller matrix elements are presented. A strong enhancement of the cross section for highly energetic neutrinos is found compared to previous phenomenological estimates. As a consequence, the present assumptions on the signal from 8 B neutrinos in 71 Ga have to be revised. A non-negligible solar model dependent background of 8 B neutrinos has to be expected in a gallium solar neutrino experiment together with the pp signal. The calculations yield a larger sensitivity of the gallium detector than assumed previously for galactic neutrinos

  7. Solar neutrino physics on the beginning of 2017

    International Nuclear Information System (INIS)

    Vissani Francesko

    2017-01-01

    This writeup is a review of current hot topics on solar neutrinos. It is based on a talk at the conference ''Neutrinos: the quest for a new physics scale'', held at the CERN on March 2017, where the Organizers entrusted me with a discussion of the provocative question ''whether solar neutrino physics is over''. Rather than providing a straight (negative) answer, in view of an audience consisting mostly of colleagues working in theoretical particle physics, I deemed it more useful providing a description of what is the current activity of the physicists working in solar neutrinos, leaving the listener free of forming his/her own opinion apropos.

  8. Solar neutrino physics on the beginning of 2017

    Directory of Open Access Journals (Sweden)

    Francesco Vissani

    2017-08-01

    Full Text Available This writeup is a review of current hot topics on solar neutrinos. It is based on a talk at the conference “Neutrinos: the quest for a new physics scale”, held at the CERN on March 2017, where the Organizers entrusted me with a discussion of the provocative question “whether solar neutrino physics is over”. Rather than providing a straight (negative answer, in view of an audience consisting mostly of colleagues working in theoretical particle physics, I deemed it more useful providing a description of what is the current activity of the physicists working in solar neutrinos, leaving the listener free of forming his/her own opinion apropos.

  9. What will the /sup 98/Mo solar-neutrino experiment measure?

    International Nuclear Information System (INIS)

    Bahcall, J.N.

    1988-01-01

    It is shown that the geochemical measurement of the solar-neutrino flux using /sup 98/Mo should yield the same value for the 8 B neutrino flux as is determined by contemporary observations using the /sup 37/Cl and Kamiokande II detectors. The /sup 98/Mo and contemporary fluxes should be equal to an accuracy of better than 1%, provided standard ideas regarding time scales in stellar evolution are correct

  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. Energy dependence of solar-neutrino--electron scattering as a test of neutral currents

    International Nuclear Information System (INIS)

    Kwong, W.; Rosen, S.P.

    1992-01-01

    The energy dependence of ν-e scattering of solar neutrinos is investigated in the framework of neutrino oscillations and the nonadiabatic Mikheyev-Smirnov-Wolfenstein effect. It is shown that, with sufficient data, it will be possible to establish unambiguously whether neutrino oscillations are actually occurring and whether the electron neutrino oscillates into active or inactive (sterile) neutrino flavors

  12. Investigation of matter enhanced neutrino oscillations relevant to the solar neutrino problem

    International Nuclear Information System (INIS)

    Losecco, J.M.; Bionta, R.M.; Casper, D.; Claus, R.; Errede, S.; Foster, G.; Park, H.S.; Seidel, S.; Shumard, E.; Sinclair, D.; Stone, J.L.; Sulak, L.; Van der Velde, J.C.; Blewitt, G.; Cortez, B.; Lehmann, E.; Bratton, C.B.; Gajewski, W.; Ganezer, K.S.; Haines, T.J.; Kropp, W.R.; Reines, F.; Schultz, J.; Sobel, H.W.; Wuest, C.; Goldhaber, M.; Jones, T.W.; Kielczewska, D.; Learned, J.G.; Svoboda, R.

    1987-01-01

    We study the effect of matter enhanced neutrino oscillations on atmospheric neutrinos. A recently proposed solution to the solar neutrino problem with Δm 2 =1.1x10 -4 eV 2 suggests enhanced effects in the range 200 MeV-500 MeV. We find no evidence of this effect for ν μ ??ν e mixing. Limits are set on the magnitude of the mixing angle. Our limit is sin θ V <0.14 at 90% confidence level. The limit is dominated by statistical errors and may be improved. (orig.)

  13. Further observation of dimuon production by neutrinos

    International Nuclear Information System (INIS)

    Benvenuti, A.; Cline, D.; Ford, W.T.; Imlay, R.; Ling, T.Y.; Mann, A.K.; Orr, R.; Reeder, D.D.; Rubbia, C.; Stefanski, R.; Sulak, L.; Wanderer, P.

    1975-01-01

    By using a quadrupole focused neutrino beam, 61 events with two muons in the final state have been observed at Fermilab. These include seven μ - μ - events. A comparison of the event rate in two targets of different hadron absorption length indicates that attributing the events to π or K leptonic decay is ruled out by 4.0 standard deviations. No trimuon events were observed; this circumstance, combined with lepton conservation, indicates an unobserved neutral lepton is present in most of the events

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

    International Nuclear Information System (INIS)

    Miranda, O.G.; Pena-Garay, C.; Valle, J.W.F.; Rashba, T.I.; Semikoz, V.B.

    2001-01-01

    The analysis of the resonant spin-flavour (RSF) solutions to the solar neutrino problem in the framework of the simplest analytical solutions to the solar magnetohydrodynamics (MHD) equations is presented. We performed the global fit of the recent solar neutrino data, including event rates as well as zenith angle distributions and 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 (e.g., SNO) to disentangle the MHD-RSF scenario from other scenarios

  15. A review of matter oscillations and solar neutrinos

    International Nuclear Information System (INIS)

    Rosen, S.P.

    1986-01-01

    We review the theory of the Mikheyev-Smirnov-Wolfenstein effect, and examine its consequences for the solar neutrino problem. Using a two-flavor model, we discuss the solutions in the Δ 2 -sin 2 2Θ parameter space for the 37 Cl experiment, and describe their predictions for the 71 Ga experiment and for the spectrum of electron-neutrinos arriving at earth. 18 refs

  16. Detector LENS as a new tool for solar neutrino spectroscopy

    International Nuclear Information System (INIS)

    Kornoukhov, V.N.

    2001-01-01

    LENS detector is a low-threshold, electron-flavor specific detector for real time measurement of the solar neutrino spectrum at low energies. It is expected that 20 tons of Yb used as a neutrino target should give several hundred events per year. The basic method for implementation of the LENS detector is scintillator technique, namely a liquid scintillator doped (up to 10% in mass) with natural Yb

  17. DETECTING GRAVITY MODES IN THE SOLAR {sup 8} B NEUTRINO FLUX

    Energy Technology Data Exchange (ETDEWEB)

    Lopes, Ilídio [Centro Multidisciplinar de Astrofísica, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa (Portugal); Turck-Chièze, Sylvaine, E-mail: ilidio.lopes@ist.utl.pt, E-mail: ilopes@uevora.pt, E-mail: sylvaine.turck-chieze@cea.fr [CEA/IRFU/Service d' Astrophysique, CE Saclay, F-91191 Gif sur Yvette (France)

    2014-09-10

    The detection of gravity modes produced in the solar radiative zone has been a challenge in modern astrophysics for more than 30 yr and their amplitude in the core is not yet determined. In this Letter, we develop a new strategy to look for standing gravity modes through solar neutrino fluxes. We note that due to a resonance effect, the gravity modes of low degree and low order have the largest impact on the {sup 8} B neutrino flux. The strongest effect is expected to occur for the dipole mode with radial order 2, corresponding to periods of about 1.5 hr. These standing gravity waves produce temperature fluctuations that are amplified by a factor of 170 in the boron neutrino flux for the corresponding period, in consonance with the gravity modes. From current neutrino observations, we determine that the maximum temperature variation due to the gravity modes in the Sun's core is smaller than 5.8 × 10{sup –4}. This study clearly shows that due to their high sensitivity to the temperature, the {sup 8} B neutrino flux time series is an excellent tool to determine the properties of gravity modes in the solar core. Moreover, if gravity mode footprints are discovered in the {sup 8} B neutrino flux, this opens a new line of research to probe the physics of the solar core as non-standing gravity waves of higher periods cannot be directly detected by helioseismology but could leave their signature on boron neutrino or on other neutrino fluxes.

  18. Solar neutrino measurements with Super-Kamiokande III

    International Nuclear Information System (INIS)

    Ikeda, Motoyasu

    2008-01-01

    The third phase of Super-Kamiokande experiment (SK-III) has been running since 12th July, 2006. The SK-III detector is achieved 40% photo-cathode coverage with 11,129 20-inch PMTs. One of the physics goals in SK-III is observing the transition of solar neutrino oscillations between vacuum and matter oscillation around 4MeV. From 24th January, 2007 to 2nd March, 2008, we obtained data of live-time 288.9 days with energy threshold 6.5MeV (Full Final sample: FF sample). For data with a lower energy threshold 5.0MeV, we needed remove high radon contaminated period from the FF sample, then we obtained another data sample (Radon reduced sample: RR sample) with live-time 191.7 days. The current measurements show that SK-III has already achieved a similar signal to noise ratio as SK-I for energy range from 5.0 to 20.0MeV, and the solar angle distribution of FF sample shows that the solar neutrino event rate also looks consistent with SK-I for energy range from 6.5 to 20.0MeV. As for the RR sample, although the vertex distribution of low energy events is not uniform in the detector and there are more BG events in the edge of fiducial volume, it is clear that SK-III BG level is smaller than that of SK-I in the central region of the detector. Finally, the future plan for lowering the energy threshold shows a 2a discovery potential of the energy spectrum upturn with 3 years of observation after both software and hardware improvements.

  19. Analytic treatments of matter-enhanced solar-neutrino oscillations

    International Nuclear Information System (INIS)

    Haxton, W.C.

    1987-01-01

    Mikheyev and Smirnov have pointed out that flavor oscillations of solar neutrinos could be greatly enhanced. The Mikheyev-Smirnov-Wolfenstein mechanism depends on the effective electron neutrino mass that arises from charged-current scattering off solar electrons, a phenomenon first discussed by Wolfenstein. Two analytic treatments, the adiabatic approximation and Landau-Zener (LZ) approximation, have been used in studies of this mechanism. I discuss a simple extension of the LZ approximation that merges naturally with the adiabatic approximation and is free of certain troublesome pathologies that arise in the conventional treatment. In this extension the solar density is approximated as in the conventional treatment, except that the starting and ending densities are the physical ones. Results of this finite LZ approximation are compared to those from the standard LZ approximation, the adiabatic approximation, and ''exact'' numerical integrations. The new approximation is virtually exact regardless of the point of origin of the neutrino in the solar core. This approximation is used to efficiently calculate the solar-neutrino capture rates for /sup 37/Cl, /sup 71/Ga, and /sup 98/Mo. The spatial extent of the solar core, the contributions of minor neutrino species, and the effects of 8 B neutrino capture to excited nuclear states are treated with care. Limits imposed on δm 2 and sin 2 2theta/sub v/ by the nonzero /sup 37/Cl capture rate are derived by considering the expected uncertainties in standard-solar-model flux estimates. Those oscillation parameters are determined that could account for the /sup 37/Cl puzzle and yet lead to a /sup 71/Ga counting rate above the minimum astronomical value

  20. Quasi-biennial periodicity in the solar neutrino flux and its relation to the solar structure

    International Nuclear Information System (INIS)

    Sakurai, K.

    1981-01-01

    By analysing the observed results on the neutrino flux from the Sun for the years 1970-1978, it is shown that the production rate of the neutrinos at the central core of the Sun had been varying with a period almost equal to 26 months for these years. This so-called 'quasi-biennial' periodicity in this rate suggests that the physical state of the central core of the Sun must have been modulated with this period through the variation of physical parameters as temperature and the chemial composition at the central core of the Sun. An idea to interpret this observed periodicity is thus proposed by taking the variations of these parameters into consideration. Some supporting evidence on this periodicity can be found on the variations of the solar activity as the relative sunspot numbers and the equatorial rotation speed of the Sun. (orig.)

  1. On the road to the solution of the Solar Neutrino Problem

    International Nuclear Information System (INIS)

    Norman, E.B.

    1995-01-01

    The present status of solar neutrino experiments is reviewed. The discrepancy between the experimental results and the theoretical expectations has come to be known as the Solar Neutrino Problem. Possible solutions to this problem are discussed. The next generation of solar neutrino experiments are described

  2. Solar neutrinos, rendezvous with the moon. An eclipse provides an indication for the huge neutrinos inquiry

    International Nuclear Information System (INIS)

    Vannucci, F.

    1996-01-01

    Solar neutrinos have raised for twenty years a puzzling problem: the neutrinos flux received on the Earth is greatly lower than the flux predicted by the prevailing model of star functioning. The neutrino oscillation hypothesis has been put forward to explain this problem. This paper describes a simple experiment carried out in Viet Nam using a telescope during a sun eclipse to measure the photon emission due to the neutrinos decay between the moon and the Earth. In this experiment, the moon plays the role of a filter which eliminates the sun photons. No significant excess of photons has been detected. This result gives some additional constraints to the existing models. (J.S.). 3 refs., 1 photo

  3. Super-Kamiokande Solar Neutrino Results and NSI Analysis

    Science.gov (United States)

    Weatherly, Pierce; Super-Kamiokande Collaboration

    2017-09-01

    Super-Kamiokande (SK) detects the Cerenkov light from elastic scattering of solar 8B neutrinos with electrons in its ultra-pure water. The directionality, energy, and timing of the recoil electrons determines the interaction rate, the flight path, as well as the energy dependence of the 8B neutrinos’ electron-flavor survival probability P ee . While the P ee below 1 MeV is equivalent to averaged vacuum neutrino flavor oscillations, the P ee above 7 MeV is suppressed by the Mikheyev-Smirnov-Wolfenstein (MSW) resonance resulting from the interaction of the solar neutrinos with solar matter. In the same way, Earth matter effects influence Pee, leading to an apparent Day/Night effect. Non-standard interactions (NSI) extend the MSW model to include interactions between the quarks in matter and neutrinos, thereby modifying P ee . We present the signatures of matter effects on solar neutrinos in Super-Kamiokande and present limits on NSI parameters, in particular couplings to the down quark.

  4. The possibility to observe the non-standard interaction by the Hyperkamiokande atmospheric neutrino experiment

    Energy Technology Data Exchange (ETDEWEB)

    Fukasawa, Shinya; Yasuda, Osamu, E-mail: yasuda@phys.se.tmu.ac.jp

    2017-01-15

    It was suggested that a tension between the mass-squared differences obtained from the solar neutrino and KamLAND experiments can be solved by introducing the non-standard flavor-dependent interaction in neutrino propagation. In this paper we discuss the possibility to test such a hypothesis by atmospheric neutrino observations at the future Hyper-Kamiokande experiment. Assuming that the mass hierarchy is known, we find that the best-fit value from the solar neutrino and KamLAND data can be tested at more than 8σ, while the one from the global analysis can be examined at 5.0σ (1.4σ) for the normal (inverted) mass hierarchy.

  5. Global Analysis of Solar Neutrino Oscillations Including SNO CC Measurement

    CERN Document Server

    Bahcall, J N; Peña-Garay, C; Bahcall, John N; Peña-Garay, Carlos

    2001-01-01

    For active and sterile neutrinos, we present the globally allowed solutions for two neutrino oscillations. We include the SNO CC measurement and all other relevant solar neutrino and reactor data. Five active neutrino oscillation solutions (LMA, LOW, SMA, VAC, and Just So2) are currently allowed at 3 sigma; three sterile neutrino solutions (Just So2, SMA, and VAC) are allowed at 3 sigma. The goodness of fit is satisfactory for all eight solutions. We also investigate the robustness of the allowed solutions by carrying out global analyses with and without: 1) imposing solar model constraints on the 8B neutrino flux, 2) including the Super-Kamiokande spectral energy distribution and day-night data, 3) using an enhanced CC cross section for deuterium (due to radiative corrections), and 4) a optimistic, hypothetical reduction by a factor of three of the error of the SNO CC rate. For every analysis strategy used in this paper, the most favored solutions all involve large mixing angles: LMA, LOW, or VAC. The favore...

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

    International Nuclear Information System (INIS)

    Elliott, Steven Ray

    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 +3.1 3.0 (stat) +2.6 -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 37 Ar neutrino source. The ratio of observed to calculated rates in this experiment, combined with the measured rates in the three prior 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 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 φ · pp = (6.1 ± 0.8) x 10 10 /(cm 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.

  7. Neutrino oscillation observables from mass matrix structure

    International Nuclear Information System (INIS)

    Winter, Walter

    2008-01-01

    We present a systematic procedure to establish a connection between complex neutrino mass matrix textures and experimental observables, including the Dirac CP phase. In addition, we illustrate how future experimental measurements affect the selection of textures in the (θ 13 ,δ CP )-plane. For the mixing angles, we use generic assumptions motivated by quark-lepton complementarity. We allow for any combination between U l and U ν , as well as we average over all present complex phases. We find that individual textures lead to very different distributions of the observables, such as to large or small leptonic CP violation. In addition, we find that the extended quark-lepton complementarity approach motivates future precision measurements of δ CP at the level of θ C ≅11 deg

  8. 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.

  9. 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.

  10. On Analytic Solution of resonant Mixing for Solar Neutrino Oscillations

    OpenAIRE

    Masatoshi, ITO; Takao, KANEKO; Masami, NAKAGAWA; Department of Physics, Meijo University; Department of Physics, Meijo University; Department of Physics, Meijo University

    1988-01-01

    Behavior of resonant mixing in matter-enhancing region for solar neutrino oscillation, the Mikheyev-Smirnov-Wolfenstein mechanism, is reanalyzed by means of an analytic treatment recently proposed. We give solutions in terms of confluent hypergeometric functions, which agree with "exact" solutions of coupled differential equations.

  11. The role of helioseismology in the knowledge of the solar interior dynamics and in the solar neutrino puzzle

    International Nuclear Information System (INIS)

    Couvidat, Sebastien

    2002-01-01

    This dissertation focuses on the solar interior dynamics and the neutrino puzzle, using helioseismology and more specifically the SoHO/GOLF data as a tool to probe the radiative interior of the Sun. We show how helioseismology gives us a direct access to the deep-layer dynamics through the solar rotation profile. Our data favor a decrease of the rotation velocity near the nuclear core. This can be used to constrain the angular momentum distribution processes, and to set an upper bound on the intensity of the magnetic field in this part of the Sun. The search for gravity modes with an original method is another topic of this dissertation. Several candidates are detected that need now to be confirmed. Gravity modes will give us a precious insight into the solar core structure and dynamics. We also use the stellar evolution code CESAM. By combining seismic data and solar modelling, we produce solar seismic models. The neutrino flux predictions from these models are partly derived on an observational basis. The comparison of these fluxes with the SNO results gives the solution to the solar neutrino puzzle: neutrinos have masses and they oscillate between different lepton flavors. This explains the deficit of detections observed since the sixties. We also work on the internal magnetic fields that take part to the dynamic processes. In particular, we start to study the impact of these fields on the neutrino production and transport. Finally, we reach the limits of the 1D stellar codes: they cannot take into account the dynamic processes efficiently. This justifies the current development of 2D or 3D codes. (author) [fr

  12. Sign of the day-night asymmetry for solar neutrinos

    International Nuclear Information System (INIS)

    Chiang, Cheng-Wei; Wolfenstein, Lincoln

    2001-01-01

    A qualitative understanding of the day-night asymmetry for solar neutrinos is provided. The greater night flux in ν e is seen to be a consequence of the fact that the matter effect in the Sun and that in the Earth have the same sign. It is shown in the adiabatic approximation for the Sun and constant density for the Earth that, for all values of the mixing angle θ V between 0 and π/2, the night flux of neutrinos is greater than the day flux. Only for small values of θ V where the adiabatic approximation badly fails does the sign of the day-night asymmetry reverse

  13. Proportional counter response calculations for gallium solar neutrino detectors

    International Nuclear Information System (INIS)

    Kouzes, R.T.; Reynolds, D.

    1989-01-01

    Gallium bases solar neutrino detectors are sensitive to the primary pp reaction in the sun. Two experiments using gallium, SAGE in the Soviet Union and GALLEX in Europe, are under construction and will produce data by 1989. The radioactive /sup 71/Ge produced by neutrinos interacting with the gallium detector material, is chemically extracted and counted in miniature proportional counters. A number of calculations have been carried out to simulate the response of these counters to the decay of /sup 71/Ge and to background events

  14. Neutrino Observation of Core Collapse Supernovae

    Science.gov (United States)

    Nakazato, Ken'ichiro

    The event rate of the supernova neutrinos are predicted for the future SK-Gd experiment. With an eye on the neutron tagging by Gd, the energy and angular distributions are calculated both for tagged events from inverse β decay reaction and untagged events from other reactions. As a result, it is indicated that the shock revival in the supernova is detectable through the decrease of the event rate and decline of the average energy of events. It is also implied that a careful treatment for the neutrino spectra is needed to investigate the untagged events owing to the high neutrino threshold energy of 16O reactions.

  15. Solar neutrino flux at keV energies

    Science.gov (United States)

    Vitagliano, Edoardo; Redondo, Javier; Raffelt, Georg

    2017-12-01

    We calculate the solar neutrino and antineutrino flux in the keV energy range. The dominant thermal source processes are photo production (γ e→ e νbar nu), bremsstrahlung (e+Ze→ Ze+e+νbar nu), plasmon decay (γ→νbar nu), and νbar nu emission in free-bound and bound-bound transitions of partially ionized elements heavier than hydrogen and helium. These latter processes dominate in the energy range of a few keV and thus carry information about the solar metallicity. To calculate their rate we use libraries of monochromatic photon radiative opacities in analogy to a previous calculation of solar axion emission. Our overall flux spectrum and many details differ significantly from previous works. While this low-energy flux is not measurable with present-day technology, it could become a significant background for future direct searches for keV-mass sterile neutrino dark matter.

  16. Treatment of solar neutrino-oscillations in solar matter. The MSW effect

    International Nuclear Information System (INIS)

    Messiah, A.

    1986-01-01

    Mikheyev and Smirnov, following Wolfenstein's theory of neutrino oscillations in the presence of matter, have found that the change of flavour of solar neutrinos may be spectacularly enhanced in the presence of solar matter, when the parameters of the neutrino mass operator fall in a suitable range (MSW effect). It is shown that this effect can be readily deduced from the adiatic solution of the equation of flavour evolution. A complete study of the two-flavour case is given, permitting to calculate, for any set of values of the mass operator parameters, the ν e suppression factor at the site of detection on earth. The adiabatic approximation holds over a wide range of the parameters, leading to especially simple expressions. Our calculations cover the whole range, including domains where the adiabatic approximation is no longer valid. Some of the results, presented in a form most suited for an analysis of solar neutrino experiments, are displayed for illustration and discussed. 7 refs

  17. A search for sterile neutrinos with the latest cosmological observations

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Lu; Zhang, Jing-Fei [Northeastern University, Department of Physics, College of Sciences, Shenyang (China); Zhang, Xin [Northeastern University, Department of Physics, College of Sciences, Shenyang (China); Peking University, Center for High Energy Physics, Beijing (China)

    2017-06-15

    We report the result of a search for sterile neutrinos with the latest cosmological observations. Both cases of massless and massive sterile neutrinos are considered in the ΛCDM cosmology. The cosmological observations used in this work include the Planck 2015 temperature and polarization data, the baryon acoustic oscillation data, the Hubble constant direct measurement data, the Planck Sunyaev-Zeldovich cluster counts data, the Planck lensing data, and the cosmic shear data. We find that the current observational data give a hint of the existence of massless sterile neutrino (as dark radiation) at the 1.44σ level, and the consideration of an extra massless sterile neutrino can indeed relieve the tension between observations and improve the cosmological fit. For the case of massive sterile neutrino, the observations give a rather tight upper limit on the mass, which implies that actually a massless sterile neutrino is more favored. Our result is consistent with the recent result of neutrino oscillation experiment done by the Daya Bay and MINOS collaborations, as well as the recent result of cosmic ray experiment done by the IceCube collaboration. (orig.)

  18. Observing Muon Neutrino to Electron Neutrino Oscillations in the NOνA Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Xin, Tian [Iowa State U.

    2016-01-01

    Neutrino oscillations offers an insight on new physics beyond the Standard Model. The three mixing angles (θ12, θ13 and θ23) and the two mass splittings (Δm2 and Αm2 ) have been measured by different neutrino oscillation experiments. Some other parameters including the mass ordering of different neutrino mass eigenstates and the CP violation phase are still unknown. NOνA is a long-baseline accelerator neutrino experiment, using neutrinos from the NuMI beam at Fermilab. The experiment is equipped with two functionally identical detectors about 810 kilometers apart and 14 mrad off the beam axis. In this configuration, the muon neutrinos from the NuMI beam reach the disappearance maximum in the far detector and a small fraction of that oscillates into electron neutrinos. The sensitivity to the mass ordering and CP viola- tion phase determination is greately enhanced. This thesis presents the νeappearance analysis using the neutrino data collected with the NOνA experiment between February 2014 and May 2015, which corresponds to 3.45 ×1020 protons-on-target (POT). The νe appearance analysis is performed by comparing the observed νe CC-like events to the estimated background at the far detector. The total background is predicted to be 0.95 events with 0.89 originated from beam events and 0.06 from cosmic ray events. The beam background is obtained by extrapolating near detector data through different oscillation channels, while the cosmic ray background is calculated based on out-of-time NuMI trigger data. A total of 6 electron neutrino candidates are observed in the end at the far detector which represents 3.3 σ excess over the predicted background. The NOνA result disfavors inverted mass hierarchy for δcp ϵ [0, 0.6π] at 90% C.L.

  19. Neutrinos today

    International Nuclear Information System (INIS)

    Pontecorvo, B.; Bilen'kij, S.

    1987-01-01

    After the famous 1983 discovery of intermediate W, Z 0 bosons it may be stated with certainty that W, Z 0 are entirely responsible for the production of neutrinos and for their interactions. Neutrino physics notions are presented from this point of view in the first four introductory, quite elementary, paragraphs of the paper. The following seven paragraphs are more sophisticated. They are devoted to the neutrino mass and neutrino mixing question, which is the most actual problem in today neutrino physics. Vacuum neutrino oscillations, matter neutrino oscillations and netrinoless double-decay are considered. Solar neutrino physics is discussed in some detail from the point of view of vacuum and matter neutrino oscillations. The role played by neutrinos in the Universe is briefly considered. In the last paragraph there discussed the probable observation by different groups of neutrinos connected with the Supernova 1987 A: the first observation of gravitational star collapse (at least the general rehearsal of such observation) opens up a new era in astronomy of today exerimental physics and astrophysics is presented at the end of the paper in the form of a Table

  20. Implications of the GALLEX determination of the solar neutrino flux

    Energy Technology Data Exchange (ETDEWEB)

    Anselmann, P.; Hampel, W.; Heusser, G.; Kiko, J.; Kirsten, T.; Pernicka, E.; Plaga, R.; Roenn, U.; Sann, M.; Schlosser, C.; Wink, R.; Wojcik, M. (Max-Pland-Inst. fuer Kernphysik, Heidelberg (Germany)); Ammon, R. von; Ebert, K.H.; Henrich, E. (Inst. fuer Heisse Chemie, Kernforschungszentrum Karlsruhe (Germany)); Balata, M.; Bellotti, E.; Ferrari, N.; Lalla, H.; Stolarczyk, T. (INFN, L' Aquila (Italy) Lab. Nazionali del Gran Sasso, L' Aquila (Italy)); Cattadori, C.; Cremonesi, O.; Fiorini, E.; Pezzoni, S.; Zanotti, L. (Dipt di Fisica, Univ. Milan (Italy) INFN, Milan (Italy)); Feilitzsch, F. von; Moessbauer, R.; Schanda, U. (Physik Dept. E15, Technische Univ. Muenchen, Garching (Germany)); Berthomieu, G.; Schatzman, E. (Observatoire de la Cote d' Azur, Dept. Cassini, 06 - Nice (France) DASGAL, Batiment Copernic, Observatoire de Paris, 92 - Meudon (France)); Carmi, I.; Dostrovsky, I. (Dept. of Environmental and Energy Research, Weizmann Inst. of Science, Rehovot (Israel)); Bacci, C.; B; GALLEX Collaboration

    1992-07-16

    The GALLEX result 83{+-}19(stat.){+-}8(syst.) SNU is two standard deviations below the predictions of stellar model calculations (124-132 SUN). To fit this result together with those of the chlorine and Kamiokande experiments requires severe stretching of solar models but does not rule out such a procedure, leaving the possibility of massless neutrinos. It clearly implies that the pp neutrinos have been detected. The Mikheyev-Smirnov-Wolfenstein (MSW) mechanism provides a good fit, and the GALLEX result fixes the {Delta}m{sup 2} and sin{sup 2}2{theta} parameters in two very confined ranges (around {Delta}m{sup 2}=6x10{sup -6} eV{sup 2} and sin{sup 2}2{theta}=7x10{sup -3} and around {Delta}m{sup 2}=8x10{sup -6} eV{sup 2} and sin{sup 2}2{theta}=0.6). Explanations of the solar neutrino problem based on the decay or magnetic interactions of neutrinos are disfavoured. (orig.).

  1. Large, real time detectors for solar neutrinos and magnetic monopoles

    International Nuclear Information System (INIS)

    Gonzalez-Mestres, L.

    1990-01-01

    We discuss the present status of superheated superconducting granules (SSG) development for the real time detection of magnetic monopoles of any speed and of low energy solar neutrinos down to the pp region (indium project). Basic properties of SSG and progress made in the recent years are briefly reviewed. Possible ways for further improvement are discussed. The performances reached in ultrasonic grain production at ∼ 100 μm size, as well as in conventional read-out electronics, look particularly promising for a large scale monopole experiment. Alternative approaches are briefly dealt with: induction loops for magnetic monopoles; scintillators, semiconductors or superconducting tunnel junctions for a solar neutrino detector based on an indium target

  2. A Scintillator Purification System for the Borexino Solar Neutrino Detector

    OpenAIRE

    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.

    2007-01-01

    Purification of the 278 tons of liquid scintillator and 889 tons of buffer shielding for the Borexino solar neutrino detector was performed with a system that combined distillation, water extraction, gas stripping and filtration. The purification of the scintillator achieved unprecedented low backgrounds for the large scale liquid scintillation detector. This paper describes the principles of operation, design, construction and commissioning of the purification system, and reviews the require...

  3. Charge exchange reactions and solar neutrino detection in 81Br

    International Nuclear Information System (INIS)

    Liu, K.F.; Gabbard, F.

    1983-01-01

    The feasibility of 81 Br as the detector of the solar neutrino flux hinges upon the knowledge of the Gamow-Teller matrix element from the ground state of 81 Br to the (5/2) - state at 0.457 MeV in 81 Kr. The possibility of obtaining this matrix element is discussed in terms of the (p,n) and ( 3 He, t) charge exchange reactions. .ID CR2009 .PG 98 112

  4. Neutrino sunshine

    International Nuclear Information System (INIS)

    Anon.

    1993-01-01

    Full text: On 10 June 1992, at the Neutrino 92 meeting in Grenada, Spain, Till Kirsten of Heidelberg's Max Planck Institute reported that neutrinos from sunshine had been seen. Most of the energy pumped out by the Sun comes from the fusion of protons into alpha particles, a process which also liberates neutrinos. While it takes about a million years for radiant energy formed in the deep interior of the Sun to fight its way to the surface, the highly penetrating neutrinos emerge almost immediately. It was in 1970 that Ray Davis and his team began taking data with a tank containing 615 tons of perchloroethylene (dry cleaning fluid) 1500 metres underground in the Homestake gold mine, South Dakota. The observed signal is consistently smaller than what is expected. This 'solar neutrino problem' was confirmed by the Kamioka mine experiment in Japan, looking at the Cherenkov light released by neutrino interactions in some 700 tons of water. However these experiments are only sensitive to a tiny high energy tail of the solar neutrino spectrum, and to understand what is going on needs measurements of the primary neutrinos from proton fusion. To get at these neutrinos, two large new detectors, using gallium and sensitive to these lower energy particles, have been built and commissioned in the past few years. The detectors are SAGE ('Soviet' American Gallium Experiment) in the Baksan Neutrino Observatory in the Caucasus, and Gallex, a team from France, Germany, Israel, Italy and the US in the Italian Gran Sasso underground Laboratory. At Grenada, Kirsten reported unmistakable signs of solar neutrinos of proton origin recorded in Gallex. SAGE and Gallex do not yet have enough data to unambiguously fix the level of primary solar neutrinos reaching the Earth, and the interpretation of the interim results tends to be subjective. However after 23 years of conditioning through watching the solar neutrinos' high energy tail, the prospect of a neutrino

  5. Search for Muon neutrino → Tau neutrino oscillations motivation and feasibility

    International Nuclear Information System (INIS)

    Zacek, V.

    1988-01-01

    Theoretical prejudices derived from solar-neutrino matter oscillations and assumptions of neutrino mass hierarchies suggest, that neutrino-oscillations are observable in laboratory with mass parameters of Δm 2 = 10 -3 -10 4 eV 2 . In particular Muon neutrino → Tau neutrino appearance searches at accelerators seem strongly motivated

  6. Status of the MSW-solution of the solar neutrino problem

    International Nuclear Information System (INIS)

    Smirnov, A.Yu.

    1992-12-01

    Status of the resonant flavor conversion is formulated in view of latest solar neutrino data. We discuss different methods of determination of neutrino parameters. The effects of third neutrino admixture as well as possible nonvacuum mixing are considered. (author). 24 refs, 5 figs

  7. Observation of oscillations of atmospheric neutrinos with the IceCube Neutrino Observatory

    International Nuclear Information System (INIS)

    Euler, Sebastian

    2014-01-01

    Neutrino oscillations have become one of the most important research topics in particle physics since their discovery 15 years ago. In the past, the study of neutrino oscillations has been largely the domain of dedicated experiments, but in the last year also the large-volume neutrino telescopes ANTARES and IceCube reported their results on the oscillations of atmospheric muon neutrinos and thus joined the community of experiments studying neutrino oscillations. The precision of their results is not yet competitive, but their sheer size and the consequently enormous statistics give rise to the expectation of a competitive measurement in the future. This thesis describes an analysis that was done on IceCube data taken with the nearly complete detector in the years 2010/2011. IceCube is the world's largest neutrino detector, located at the geographic South Pole, where it uses the Antarctic ice sheet as its detection medium. It detects neutrinos interacting within or close to the instrumented volume by observing the Cherenkov light which is emitted by secondary particles produced in these interactions. An array of optical sensors deployed within a cubic kilometer of ice detects the Cherenkov light and makes it possible to reconstruct the energy and direction of the initial neutrino. Unfortunately, IceCube detects not only neutrinos: the desired neutrino signal is buried in a huge background of atmospheric muons, produced in air showers induced by cosmic rays. This background has to be rejected first. The analysis presented here employs an event selection that is based on the idea of using the outer layers of IceCube as an active veto against the background of atmospheric muons and achieves the necessary background rejection of more than 6 orders of magnitude while keeping a high-statistics sample of several thousands of muon neutrinos. In contrast to the earlier IceCube analysis, which used only the zenith angle, it then performs a 2-dimensional likelihood fit on

  8. Observations in particle physics: from two neutrinos to standard model

    International Nuclear Information System (INIS)

    Lederman, L.M.

    1990-01-01

    Experiments, which have made their contribution to creation of the standard model, are discussed. Results of observations on the following concepts: long-lived neutral V-particles, violation of preservation of parity and charge invariance in meson decays, reaction with high-energy neutrino and existence of neutrino of two types, partons and dynamic quarks, dimuon resonance at 9.5 GeV in 400 GeV-proton-nucleus collisions, are considered

  9. Precision Measurement of the Be7 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.

    2011-09-01

    The rate of neutrino-electron elastic scattering interactions from 862 keV Be7 solar neutrinos in Borexino is determined to be 46.0±1.5(stat)-1.6+1.5(syst)counts/(day·100ton). This corresponds to a νe-equivalent Be7 solar neutrino flux of (3.10±0.15)×109cm-2s-1 and, under the assumption of νe 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 5.0σ. A global solar neutrino analysis with free fluxes determines Φpp=6.06-0.06+0.02×1010cm-2s-1 and ΦCNOMikheyev-Smirnov-Wolfenstein large mixing angle neutrino oscillation model is experimentally tested at low energy.

  10. Is CP violation observable in long baseline neutrino oscillation experiments?

    International Nuclear Information System (INIS)

    Tanimoto, M.

    1997-01-01

    We have studied CP violation originating from the phase of the neutrino-mixing matrix in the long baseline neutrino oscillation experiments. The direct measurement of CP violation is the difference of the transition probabilities between CP-conjugate channels. In those experiments, the CP-violating effect is not suppressed if the highest neutrino mass scale is taken to be 1 endash 5 eV, which is appropriate for the cosmological hot dark matter. Assuming the hierarchy for the neutrino masses, the upper bounds of CP violation have been calculated for three cases, in which mixings are constrained by the recent short baseline ones. The calculated upper bounds are larger than 10 -2 , which will be observable in the long baseline accelerator experiments. The matter effect, which is not CP invariant, has been also estimated in those experiments. copyright 1997 The American Physical Society

  11. Precision Measurement of the Beryllium-7 Solar Neutrino Interaction Rate in Borexino

    Science.gov (United States)

    Saldanha, Richard Nigel

    Solar neutrinos, since their first detection nearly forty years ago, have revealed valuable information regarding the source of energy production in the Sun, and have demonstrated that neutrino oscillations are well described by the Large Mixing Angle (LMA) oscillation parameters with matter interactions due to the Mikheyev-Smirnov-Wolfenstein (MSW) effect. This thesis presents a precision measurement of the 7Be solar neutrino interaction rate within Borexino, an underground liquid scintillator detector that is designed to measure solar neutrino interactions through neutrino-electron elastic scattering. The thesis includes a detailed description of the analysis techniques developed and used for this measurement as well as an evaluation of the relevant systematic uncertainties that affect the precision of the result. The rate of neutrino-electron elastic scattering from 0.862 MeV 7Be neutrinos is determined to be 45.4 +/- 1.6 (stat) +/- 1.5 (sys) counts/day/100 ton. Due to extensive detector calibrations and improved analysis methods, the systematic uncertainty in the interaction rate has been reduced by more than a factor of two from the previous evaluation. In the no-oscillation hypothesis, the interaction rate corresponds to a 0.862 MeV 7Be electron neutrino flux of (2.75 +/- 0.13) x 10 9 cm-2 sec-1. Including the predicted neutrino flux from the Standard Solar Model yields an electron neutrino survival probability of Pee 0.51 +/- 0.07 and rules out the no-oscillation hypothesis at 5.1sigma The LMA-MSW neutrino oscillation model predicts a transition in the solar Pee value between low ( 10 MeV) energies which has not yet been experimentally confirmed. This result, in conjunction with the Standard Solar Model, represents the most precise measurement of the electron neutrino survival probability for solar neutrinos at sub-MeV energies.

  12. Mikheyev-Smirnov-Wolfenstein enhancement of oscillations as a possible solution to the solar-neutrino problem

    International Nuclear Information System (INIS)

    Rosen, S.P.; Gelb, J.M.

    1986-01-01

    Mikheyev and Smirnov have observed that neutrino oscillations in the Sun can be greatly enhanced through the mechanism of Wolfenstein matter oscillations. We develop a qualitative understanding of this phenomenon in the small-mixing-angle limit and carry out extensive calculations in order to apply it to the solar-neutrino problem. Our simple theoretical model agrees remarkably well with the calculations. After determining those values of Δm 2 and sin 2 2theta in the small-mixing-angle limit for which the 8 B plus 7 Be neutrino capture rate in /sup 37/Cl is suppressed by a factor 2--4, we predict the corresponding capture rate for pp plus 7 Be neutrinos in /sup 71/Ga. The gallium capture rate can range from no reduction to a factor of 10 reduction. We also determine the modified spectrum of 8 B neutrinos arriving at Earth and discuss the importance of this spectrum as a means of choosing between oscillations and the solar model as the cause of the solar-neutrino problem, and also as a means of distinguishing between different sets of oscillation parameters

  13. Evidence for Mikheyev-Smirnov-Wolfenstein effects in solar neutrino flavor transitions

    OpenAIRE

    G. L. FogliU. of Bari and INFN, Bari; E. Lisi(U. of Bari and INFN, Bari); A. Marrone(U. of Bari and INFN, Bari); A Palazzo(U. of Bari and INFN, Bari)

    2015-01-01

    We point out that the recent data from the Sudbury Neutrino Observatory, together with other relevant measurements from solar and reactor neutrino experiments, convincingly show that the flavor transitions of solar neutrinos are affected by Mikheyev-Smirnov-Wolfenstein (MSW) effects. More precisely, one can safely reject the null hypothesis of no MSW interaction energy in matter, despite the fact that the interaction amplitude (formally treated as a free parameter) is still weakly constrained...

  14. Feasibility study for a first observation of coherent neutrino nucleus scattering using low-temperature detectors

    International Nuclear Information System (INIS)

    Guetlein, Achim

    2013-01-01

    Coherent Neutrino Nucleus Scattering (CNNS) is a neutral current process of the weak interaction. For low transferred momenta the neutrino scatters coherently off all nucleons leading to an enhanced cross section. However, because of the small resulting recoil energies (O(keV)) CNNS has not been observed experimentally so far. For the first observation of CNNS a strong neutrino source is needed. Thus, the expected count rates for solar neutrinos, supernova neutrinos, neutrinos generated by the decay of stopped π + particles at accelerators, and reactor neutrinos were calculated. Although an observation of CNNS could also be possible with other sources, the most promising neutrino sources are nuclear reactors with thermal powers between 2 and 4 GW. For an assumed energy threshold of 0.5 keV the target material with the largest count rate (∝10 kg -1 day -1 ) is sapphire. Thus, a low-temperature detector based on a 32 g sapphire crystal was designed and built to measure the background spectrum for energies below ∝10 keV. Although the energy threshold (∝1 keV) of this detector is too large for an observation of CNNS, the measured background spectrum can still be used for an investigation of the main background sources and the suppression of their events. For this investigation the simulated spectra of cosmic muons, ambient neutrons, and external gamma-rays are compared to the measured background spectrum. As a result, cosmic muons are the main contribution to the measured background spectrum. For a future experiment aiming at the observation of CNNS an array of 125 low-temperature detectors based on 32 g sapphire crystals is assumed. Background simulations of cosmic muons, ambient neutrons, and intrinsic radioactivity show that especially an efficient muon-veto system is crucial for a sufficient background suppression. To study the observation potential of this future experiment a distance of ∝ 40 m to a reactor core with a thermal power of ∝4 GW (neutrino

  15. Direct Measurement of the 7Be Solar Neutrino Flux with 192 Days of Borexino Data

    International Nuclear Information System (INIS)

    Arpesella, C.; Di Pietro, G.; Monzani, M. E.; Back, H. O.; Hardy, S.; Joyce, M.; Manecki, S.; Raghavan, R. S.; Rountree, D.; Vogelaar, R. B.; Balata, M.; Di Credico, A.; Gazzana, S.; Korga, G.; Laubenstein, M.; Orsini, M.; Papp, L.; Razeto, A.; Tartaglia, R.; Bellini, G.

    2008-01-01

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

  16. Charge exchange reactions and the efficiency of solar neutrino detectors

    International Nuclear Information System (INIS)

    Austin, S.M.; Anantaraman, N.; Love, W.G.

    1994-01-01

    The efficiencies of solar neutrino detectors are often based in part on weak interaction strengths determined by (p,n) and other charge exchange reactions. Although the (p,n) determinations are surprisingly good, it is shown that they may be inaccurate for important Gamow-Teller transitions whose strengths are a small fraction of the sum rule limit. This emphasizes the importance of direct calibration with ν sources for detectors such as 127 I and 115 In where direct β-decay information cannot be obtained. It may also bear on recent attempts to compare charge exchange and beta decay in the mass-37 system

  17. Quasi-biennial modulation of solar neutrino flux: connections with solar activity

    Science.gov (United States)

    Vecchio, A.; Laurenza, M.; D'alessi, L.; Carbone, V.; Storini, M.

    2011-12-01

    A quasi-biennial periodicity has been recently found (Vecchio et al., 2010) in the solar neutrino flux, as detected at the Homestake experiment, as well as in the flux of solar energetic protons, by means of the Empirical Modes Decomposition technique. Moreover, both fluxes have been found to be significantly correlated at the quasi-biennial timescale, thus supporting the hypothesis of a connection between solar neutrinos and solar activity. The origin of this connection is investigated, by modeling how the standard Mikheyev-Smirnov-Wolfenstein (MSW) effect (the process for which the well-known neutrino flavor oscillations are modified in passing through the material) could be influenced by matter fluctuations. As proposed by Burgess et al., 2004, by introducing a background magnetic field in the helioseismic model, density fluctuations can be excited in the radiative zone by the resonance between helioseismic g-modes and Alfvén waves. In particular, with reasonable values of the background magnetic field (10-100 kG), the distance between resonant layers could be of the same order of neutrino oscillation length. We study the effect over this distance of a background magnetic field which is variable with a ~2 yr period, in agreement with typical variations of solar activity. Our findings suggest that the quasi-biennial modulation of the neutrino flux is theoretically possible as a consequence of the magnetic field variations in the solar interior. A. Vecchio, M. Laurenza, V. Carbone, M. Storini, The Astrophysical Journal Letters, 709, L1-L5 (2010). C. Burgess, N. S. Dzhalilov, T. I. Rashba, V., B.Semikoz, J. W. F. Valle, Mon. Not. R. Astron. Soc., 348, 609-624 (2004).

  18. Vacuum oscillation solution to the solar neutrino problem in standard and nonstandard pictures

    International Nuclear Information System (INIS)

    Berezhiani, Z.G.; Rossi, A.

    1995-01-01

    The neutrino long wavelength (just-so) oscillation is reexamined as a solution to the solar neutrino problem. We consider the just-so scenario in various cases: in the framework of the solar models with a relaxed prediction of the boron neutrino flux, as well as in the presence of the nonstandard weak range interactions between neutrino and matter constituents. We show that the fit of the experimental data in the just-so scenario is not very good for any reasonable value of the 8 B neutrino flux, but it substantially improves if the nonstandard τ-neutrino--electron interaction is included. These new interactions could also remove the conflict of the just-so picture with the shape of the SN 1987A neutrino spectrum. Special attention is devoted to the potential of the future real-time solar neutrino detectors such as Super-Kamiokande, SNO, and BOREXINO, which could provide the model-independent tests for the just-so scenario. In particular, these imply a specific deformation of the original solar neutrino energy spectra and time variation of the intermediate energy monochromatic neutrino ( 7 Be and pep) signals

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

    Energy Technology Data Exchange (ETDEWEB)

    Franco, D.; Agnes, P. [APC, Université Paris Diderot, CNRS/IN2P3, CEA/Irfu, Observatoire de Paris, Sorbonne Paris Cité, Paris 75205 (France); Giganti, C.; Agostino, L.; De Cecco, S., E-mail: dfranco@in2p3.fr, E-mail: cgiganti@lpnhe.in2p3.fr, E-mail: pagnes@in2p3.fr, E-mail: lagostin@lpnhe.in2p3.fr, E-mail: sandro.dececco@lpnhe.in2p3.fr [LPNHE Paris, Université Pierre et Marie Curie, Université Paris Diderot, CNRS/IN2P3, Paris 75252 (France); and others

    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 {sup 7}Be and pep neutrino rates compared to the currently available results from the Borexino organic liquid scintillator detector.

  20. Solar neutrinos as a signal and background in direct-detection experiments searching for sub-GeV dark matter with electron recoils

    Science.gov (United States)

    Essig, Rouven; Sholapurkar, Mukul; Yu, Tien-Tien

    2018-05-01

    Direct-detection experiments sensitive to low-energy electron recoils from sub-GeV dark matter interactions will also be sensitive to solar neutrinos via coherent neutrino-nucleus scattering (CNS), since the recoiling nucleus can produce a small ionization signal. Solar neutrinos constitute both an interesting signal in their own right and a potential background to a dark matter search that cannot be controlled or reduced by improved shielding, material purification and handling, or improved detector design. We explore these two possibilities in detail for semiconductor (silicon and germanium) and xenon targets, considering several possibilities for the unmeasured ionization efficiency at low energies. For dark-matter-electron-scattering searches, neutrinos start being an important background for exposures larger than ˜1 - 10 kg -years in silicon and germanium, and for exposures larger than ˜0.1 - 1 kg -year in xenon. For the absorption of bosonic dark matter (dark photons and axion-like particles) by electrons, neutrinos are most relevant for masses below ˜1 keV and again slightly more important in xenon. Treating the neutrinos as a signal, we find that the CNS of 8B neutrinos can be observed with ˜2 σ significance with exposures of ˜2 , 7, and 20 kg-years in xenon, germanium, and silicon, respectively, assuming there are no other backgrounds. We give an example for how this would constrain nonstandard neutrino interactions. Neutrino components at lower energy can only be detected if the ionization efficiency is sufficiently large. In this case, observing pep neutrinos via CNS requires exposures ≳10 - 100 kg -years in silicon or germanium (˜1000 kg -years in xenon), and observing CNO neutrinos would require an order of magnitude more exposure. Only silicon could potentially detect 7Be neutrinos. These measurements would allow for a direct measurement of the electron-neutrino survival probability over a wide energy range.

  1. On the presence of fictitious solar neutrino flux variations in radiochemical experiments

    International Nuclear Information System (INIS)

    Vladimirskii, B.M.; Bruns, A.V.

    2004-01-01

    The currently available data on solar neutrino flux variation in radiochemical experiments and Cherenkov measurements have so far defied a simple interpretation. Some of the results concerning these variations are indicative of their relationship to processes on the solar surface. It may well be that a poorly understood, uncontrollable factor correlating with solar activity indices affects the neutrino flux measurements. This factor is assumed to modulate the detection efficiency on different detectors in different ways. To test this assumption, we have analyzed all available radiochemical measurements obtained with the Brookhaven (1970-1994, 108 runs), GALLEX (1991-1997, 65 runs), and SAGE (1989-2000, 80 runs) detectors for possible instability of the detection efficiency. We consider the heliophysical situation at the final stage of the run, the last 7-27 days, when the products of the neutrino reaction with the target material had already been accumulated. All of the main results obtained previously by other authors were found to be reproduced for chlorine-argon measurements. The neutrino flux anticorrelates with the sunspot numbers only for an odd solar cycle. A similar behavior is observed for the critical frequencies of the E-ionosphere. The neutrino flux probably correlates with the A p magnetic activity index only for an even solar cycle. The predominance of a certain sign of the radial interplanetary magnetic field (IMF) in the last 14 (or 7) days of the run has the strongest effect on the recorded neutrino flux. The effect changes sign when the polarity of the general solar magnetic field is reversed and is most pronounced for the shortest runs (less than 50 days). The dependence of the flux on IMF polarity completely disappears if the corresponding index is taken for the first rather than the last days of the run. The IMF effect on the recorded neutrino flux was also found for short runs in the gallium-germanium experiment, but this effect for a given

  2. Solar neutrino flux measurements by the Soviet-American Gallium Experiment (SAGE) for half the 22-year solar cycle

    International Nuclear Information System (INIS)

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

    2002-01-01

    We present measurements of the solar neutrino capture rate on metallic gallium in the Soviet-American gallium experiment (SAGE) over a period of slightly more than half the 22-year solar cycle. A combined analysis of 92 runs over the twelve-year period from January 1990 until December 2001 yields a capture rate of 70.8 +5.3 -5.2 (stat) +3.7 -3.2 (sys) SNU for solar neutrinos with energies above 0.233 MeV. This value is slightly more than half the rate predicted by the standard solar model, 130 SNU. We present the results of new runs since April 1998 and analyze all runs combined by years, months, and bimonthly periods beginning in 1990. A simple analysis of the SAGE results together with the results of other solar neutrino experiments gives an estimate of (4.6 ± 1.2) x 10 10 neutrinos cm -2 s -1 for the flux of the electron pp neutrinos that reach the Earth without changing their flavor. The flux of the pp neutrinos produced in thermonuclear reactions in the Sun is estimated to be (7.6 ± 2.0) x 10 10 neutrinos cm -2 s -1 , in agreement with the value of (5.95 ± 0.06) x 10 10 neutrinos cm -2 s -1 predicted by the standard solar model

  3. The effect of random matter density perturbations on the large mixing angle solution to the solar neutrino problem

    Science.gov (United States)

    Guzzo, M. M.; Holanda, P. C.; Reggiani, N.

    2003-08-01

    The neutrino energy spectrum observed in KamLAND is compatible with the predictions based on the Large Mixing Angle realization of the MSW (Mikheyev-Smirnov-Wolfenstein) mechanism, which provides the best solution to the solar neutrino anomaly. From the agreement between solar neutrino data and KamLAND observations, we can obtain the best fit values of the mixing angle and square difference mass. When doing the fitting of the MSW predictions to the solar neutrino data, it is assumed the solar matter do not have any kind of perturbations, that is, it is assumed the the matter density monothonically decays from the center to the surface of the Sun. There are reasons to believe, nevertheless, that the solar matter density fluctuates around the equilibrium profile. In this work, we analysed the effect on the Large Mixing Angle parameters when the density matter randomically fluctuates around the equilibrium profile, solving the evolution equation in this case. We find that, in the presence of these density perturbations, the best fit values of the mixing angle and the square difference mass assume smaller values, compared with the values obtained for the standard Large Mixing Angle Solution without noise. Considering this effect of the random perturbations, the lowest island of allowed region for KamLAND spectral data in the parameter space must be considered and we call it very-low region.

  4. The Russian-American Gallium solar neutrino Experiment (SAGE)

    International Nuclear Information System (INIS)

    Bowles, T.J.

    1994-01-01

    The Russian-American Gallium Experiment (SAGE) began measurements of the integral flux of solar neutrinos using 30 tons of metallic gallium as the target in January 1990. The mass of the gallium was increased to 57 tons in September 1991 and SAGE began to count the decay of 71 Ge using both the K and L peaks in September 1992. The results indicate a deficit of about 40% of the flux predicted by the Standard Solar Model. The chemical extraction and counting techniques used by SAGE are presented, with particular attention on backgrounds. The present status, results, and future plans of SAGE are presented, along with a discussion of the possible physics implications

  5. The new Wide-band Solar Neutrino Trigger for Super-Kamiokande

    Science.gov (United States)

    Carminati, Giada

    Super-Kamiokande observes low energy electrons induced by the elastic scattering of 8B solar neutrinos. The transition region between vacuum and matter oscillations, with neutrino energy near 3 MeV, is still partially unexplored by any detector. Super-Kamiokande can study this intermediate regime adding a new software trigger. The Wide-band Intelligent Trigger (WIT) has been developed to simultaneously trigger and reconstruct very low energy electrons (above 2.49 kinetic MeV) with an e_ciency close to 100%. The WIT system, comprising 256-Hyperthreaded CPU cores and one 10-Gigabit Ethernet network switch, has been recently installed and integrated in the online DAQ system of SK and the complete system is currently in an advanced status of online data testing.

  6. A search for matter enhanced neutrino oscillations through measurements of day and night solar neutrino fluxes at the Sudbury Neutrino Observatory

    Science.gov (United States)

    Miknaitis, Kathryn Kelly Schaffer

    The Sudbury Neutrino Observatory (SNO) is a heavy-water Cherenkov detector designed to study 8B neutrinos from the sun. Through the charged-current (CC) and neutral-current (NC) reactions of neutrinos on deuterium, SNO separately determines the flux of electron neutrinos and the flux of all active flavors of solar 8B neutrinos. SNO is also sensitive to the elastic scattering (ES) of neutrinos on electrons in the heavy water. Measurements of the CC and NC rates in SNO have conclusively demonstrated solar neutrino flavor change. This flavor change is believed to be caused by matter-enhanced oscillations in the sun, through the Mikheyev-Smirnov-Wolfenstein (MSW) effect. Matter effects could also change the flavor composition of neutrinos that traverse the earth. A comparison of the day and night measured CC flux at SNO directly tests for the MSW effect and contributes to constraints on neutrino oscillation parameters in the MSW model. We perform measurements of the day and night neutrino fluxes using data from the second phase of SNO, in which salt (NaCl) was added to the heavy water to enhance sensitivity to the NC reaction. Better discrimination between CC and NC events in the salt phase allows the fluxes to be determined without constraining the neutrino energy spectrum. The day-night asymmetry in the CC flux measured in this model-independent analysis is ACC = [-5.6 +/- 7.4(stat.) +/- 5.3(syst.)]%, where the asymmetry is defined as the difference between the night and day values divided by their average. The asymmetries in the NC and ES fluxes are ANC = [4.2 +/- 8.6(stat.) +/- 7.2(syst.)]%, and AES = (14.6 +/- 19.8(stat.) +/- 3.3(syst.)]%. The neutral current asymmetry is expected to be zero assuming standard neutrino oscillations. When we constrain it to be zero, we obtain ACC = [-3.7 +/- 6.3(stat.) +/- 3.2(syst.)]% and AES = [15.3 +/- 19.8(stat.) +/- 3.0(syst.)]%. The day and night energy spectra from the CC reaction have been measured and show no evidence for

  7. The MSW conversion of solar neutrinos and random matter density perturbations

    International Nuclear Information System (INIS)

    Nunokawa, H.; Rossi, A.; Valle, J.W.F.

    1997-01-01

    A generalization of the resonant neutrino conversion in matter, including a random component in the matter density profile is presented. 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 ν e → ν μ , τ as well as active-sterile ν e → conversion channels. The small mixing MSW solution is much more stable than the large mixing solution has been found. Future solar neutrino experiments, such as Borexino, could probe solar matter density noise at the few percent level

  8. 7Be(p, γ)8B and the high-energy solar neutrino flux

    International Nuclear Information System (INIS)

    Csoto, A.

    1997-01-01

    Despite thirty years of extensive experimental and theoretical work, the predicted solar neutrino flux is still in sharp disagreement with measurements. The solar neutrino measurements strongly suggest that the problem cannot be solved within the standard electroweak and astrophysical theories. Thus, the solar neutrino problem constitutes the strongest evidence for physics beyond the Standard Model. Whatever the solution of the solar neutrino problem turns out to be, it is of paramount importance that the input parameters of the underlying electroweak and solar theories rest upon solid ground. The most uncertain nuclear input parameter in standard solar models is the low-energy 7 Be(p, γ) 8 B radiative capture cross section. This reaction produces 8 B in the Sun, whose β + decay is the main source of the high-energy solar neutrinos. Here, the importance of the 7 Be(p, γ) 8 B reaction in predicting the high energy solar neutrino flux is discussed. The author presents a microscopic eight-body model and a potential model for the calculation of the 7 Be(p, γ) 8 B cross section

  9. High resolution solar observations

    International Nuclear Information System (INIS)

    Title, A.

    1985-01-01

    Currently there is a world-wide effort to develop optical technology required for large diffraction limited telescopes that must operate with high optical fluxes. These developments can be used to significantly improve high resolution solar telescopes both on the ground and in space. When looking at the problem of high resolution observations it is essential to keep in mind that a diffraction limited telescope is an interferometer. Even a 30 cm aperture telescope, which is small for high resolution observations, is a big interferometer. Meter class and above diffraction limited telescopes can be expected to be very unforgiving of inattention to details. Unfortunately, even when an earth based telescope has perfect optics there are still problems with the quality of its optical path. The optical path includes not only the interior of the telescope, but also the immediate interface between the telescope and the atmosphere, and finally the atmosphere itself

  10. New physics in the new millennium with GENIUS: double beta decay, dark matter, solar neutrinos

    International Nuclear Information System (INIS)

    Klapdor-Kleingrothaus, H.V.

    2001-01-01

    Double beta decay is indispensable to solve the question of the neutrino mass matrix together with ν oscillation experiments. The most sensitive experiment since eight years - the HEIDELBERG - MOSCOW experiment in Gran Sasso - already now, with the experimental limit of ν > 7 Be) solar neutrinos. A GENIUS Test Facility has just been funded and will come into operation by the end of 2001

  11. The photodissociation of 8B and the solar neutrino problem

    International Nuclear Information System (INIS)

    Bertulani, C.A.

    1995-01-01

    The extraction of the photodissociation cross sections of 8 B from Coulomb dissociation experiments is investigated. A careful study is done on the contributions of the E1, E2 and M1 multipolarities to the breakup. A comparison with the data of a recent experiment is performed. It is shown that the extraction of the radiative capture cross sections 7 Be(p, γ) 8 B which are relevant for the solar neutrino problem is not affected appreciably by Coulomb reacceleration. A non-perturbative model is used for the purpose. Emphasis is put on the perspectives for future experiments which are planned at the University of Notre Dame, RIKEN (Japan), and GSI (Germany). An analysis of the total yields of ''photon-point'' processes in inelastic electron scattering is also done. (orig.)

  12. The Neutrinos Saga

    International Nuclear Information System (INIS)

    La Souchere, Marie-Christine de; Moran, John

    2009-04-01

    The author proposes a history of the discovery and study of neutrinos. This history starts shortly after the discovery of radioactivity in 1896 with the observation of an inhomogeneous deceleration of electrons in the radioactive source which raised an issue of shortage of energy. Pauli then introduced the idea of a ghost particle which could preserve the principle of energy conservation and also the issue of statistics related to the laws of quantum mechanics. Works by the Joliot-Curies and Chadwick resulted in the identification of a neutral particle, first called a neutron, and then neutrino. The author then reports experiments performed to highlight neutrinos, and to identify different forms of neutrinos: muon, tau, lepton. She also addresses questions raised by solar neutrinos, experiments proving the metamorphosis of electron neutrinos into muon neutrinos. She discusses the interest of neutrino as cosmic messengers as they are emitted by various cosmic events, and also as a way to study dark matter

  13. Observation of neutrino-like interactions without muon or electron in the Gargamelle neutrino experiment

    CERN Document Server

    Hasert, F J; Krenz, W; Conta, C; Von Krogh, J; Lanske, D; Morfín, J G; Schultze, K; Weerts, H; Bertrand-Coremans, G H; Sacton, J; Van Doninck, W K; Vilain, P; Camerini, U; Cundy, Donald C; Baldi, R; Danilchenko, I A; Fry, W F; Haidt, Dieter; Natali, S; Musset, P; Osculati, B; Palmer, R; Pattison, John Bryan M; Perkins, Donald Hill; Pullia, Antonio; Rousset, A; Venus, W A; Wachsmuth, H W; Brisson, V; Degrange, B; Haguenauer, Maurice; Kluberg, L; Nguyen-Khac, U; Petiau, P; Belotti, E; Bonetti, S; Cavalli, D; Fiorini, Ettore; Rollier, M; Aubert, Bernard; Blum, D; Chounet, L M; Heusse, P; Lagarrigue, A; Lutz, A M; Orkin-Lecourtois, A; Vialle, J P; Bullock, F W; Esten, M J; Jones, T W; McKenzie, J; Michette, A G; Myatt, Gerald; Scott, W G

    1974-01-01

    Events induced by neutral particles and producing only hadrons, but no muon or electron, have been observed in the heavy liquid bubble chamber Gargamelle exposed to neutrino ( nu ) and antineutrino ( nu ) beams at CERN. A study of the various sources which could give rise to such events reveals that less than 20% could be attributed to neutrons or K/sub L/ degrees . The events behave as expected if they arise from neutral current processes induced by neutrinos and antineutrinos. The ratio of the number of these events to the number of corresponding events with charged lepton is 0.22+or-0.04 for nu and 0.43+or-0.12 for nu . (8 refs).

  14. 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...

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

    International Nuclear Information System (INIS)

    Gelb, J.M.; Kwong, W.; Rosen, S.P.

    1992-01-01

    We compare the implications for 7 Be 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 2. The consequences for BOREXINO and similar solar neutrino-electron scattering experiments are discussed

  17. Coherence and the day-night asymmetry in the solar neutrino flux

    International Nuclear Information System (INIS)

    Dighe, A.S.; Liu, Q.Y.; Smirnov, A.Yu.

    1999-12-01

    We consider the day-night asymmetries predicted by various MSW solutions of the solar neutrino problem. The integration over the neutrino energy, as well as over the production region or over the time intervals of more than a day leads to the averaging of oscillations on the way to the earth. This is equivalent to considering the neutrino state arriving at the surface of the earth as an incoherent mixture of the neutrino mass eigenstates (even if there is no divergence of wavepackets). As a consequence, the regeneration effect inside the earth is incoherent, in contrast with the results in hep-ph/9902435. (author)

  18. Frontier of solar observation. Solar activity observed by 'HINODE' mission

    International Nuclear Information System (INIS)

    Watanabe, Tetsuya

    2008-01-01

    After launched in September 2006, solar observation satellite 'HINODE' has been a solar observatory on orbit with the scientific instruments well operated and its continuous observation was conducted steadily on almost all solar atmospheres from photosphere to corona. 'HINODE' was equipped with the solar optical telescope, extreme-ultraviolet imaging spectrometer and x-ray telescope and aimed at clarifying the mystery of solar physics related with coronal heating and magnetic reconnection. Present state of 'HINODE' was described from observations made in initial observation results, which have made several discoveries, such as Alfven waves in the corona, unexpected dynamics in the chromosphere and photosphere, continuous outflowing plasma as a possible source of solar wind, and fine structures of magnetic field in sunspots and solar surface. (T. Tanaka)

  19. First observation of low energy electron neutrinos in a liquid argon time projection chamber

    Energy Technology Data Exchange (ETDEWEB)

    Acciarri, R.; Adams, C.; Asaadi, J.; Baller, B.; Bolton, T.; Bromberg, C.; Cavanna, F.; Church, E.; Edmunds, D.; Ereditato, A.; Farooq, S.; Fitzpatrick, R. S.; Fleming, B.; Hackenburg, A.; Horton-Smith, G.; James, C.; Lang, K.; Luo, X.; Mehdiyev, R.; Page, B.; Palamara, O.; Rebel, B.; Schukraft, A.; Scanavini, G.; Soderberg, M.; Spitz, J.; Szelc, A. M.; Weber, M.; Yang, T.; Zeller, G. P.

    2017-04-06

    Liquid argon time projection chambers (LArTPCs) produce remarkable fidelity in the observation of neutrino interactions. The superior capabilities of such detectors to reconstruct the spatial and calorimetric information of neutrino events have made them the detectors of choice in a number of experiments, specifically those looking to observe electron neutrino ($\

  20. Measurement of solar neutrinos flux in Russian-American gallium experiment SAGE for half 22-years cycle of solar activity

    International Nuclear Information System (INIS)

    Abdurashitov, D.N.; Veretenkin, E.P.; Vermul, V.M.

    2002-01-01

    The results of measuring the solar neutrino capture on the metallic gallium in the Russian-American experiment SAGE for the period slightly exceeding the half of the 22-year cycle of solar activity, are presented. The results of new measurements since April 1998 are quoted and the analysis of all the measurements, performed by years, months and two-year periods, beginning since 1990 are also presented. Simple analysis of the SAGE results together with the results of other solar neutrino experiments leads to estimating the value of the flux of the pp-neutrinos, reaching the Earth without change in their around, equal to (4.6 ± 1.2) x 10 10 neutrino/(cm 2 s). The value of the flux of the pp-neutrinos, originating in the Sun thermonuclear reactions, is equal to (7.6 ± 2.0) x 10 10 neutrino/(cm 2 s), which agrees well with the standard solar model (5.95 ± 0.6) x 10 10 neutrino/(cm 2 s) [ru

  1. Feasibility of a 81Br(ν,e-) 81Kr solar neutrino experiment

    International Nuclear Information System (INIS)

    Hurst, G.S.; Chen, C.H.; Kramer, S.D.; Cleveland, B.T.; Davis, R. Jr.; Rowley, R.K.; Gabbard, F.; Schima, F.J.

    1984-01-01

    A solar neutrino experiment utilizing the interaction of 81 Br(ν,e - ) 81 Kr to study the 7 Be neutrino source in the interior of the sun is shown to be feasible. Resonance ionization spectroscopy was used to count less than 1000 atoms of 2 x 10 5 -yr 81 Kr, making the bromine experiment possible. Except for the method of counting product atoms, the bromine experiment would be very similar to the successful chlorine detector 37 Cl(ν,e - ) 37 Ar, and thus it is a natural sequel to the only solar neutrino experiment to date

  2. Observation of elastic neutrino-proton scattering

    International Nuclear Information System (INIS)

    Cline, D.; Entenberg, A.; Kozanecki, W.; Mann, A.K.; Reeder, D.D.; Rubbia, C.; Strait, J.; Sulak, L.; Williams, H.H.

    1976-01-01

    We have observed thirty events of the process νp→νp with a background expectations of seven events. The neutral-current to charged-current ratio sigma (νp→νp)/sigma (νn→μ - p) is measured to be 0.17 +- 0.05 for 0.3 2 2 where -q 2 is the square of the four-momentum transfer to the proton

  3. Evidence for Mikheyev-Smirnov-Wolfenstein effects in solar neutrino flavor transitions

    International Nuclear Information System (INIS)

    Fogli, G.L.; Lisi, E.; Marrone, A.; Palazzo, A.

    2004-01-01

    We point out that the recent data from the Sudbury Neutrino Observatory, together with other relevant measurements from solar and reactor neutrino experiments, convincingly show that the flavor transitions of solar neutrinos are affected by Mikheyev-Smirnov-Wolfenstein (MSW) effects. More precisely, one can safely reject the null hypothesis of no MSW interaction energy in matter, despite the fact that the interaction amplitude (formally treated as a free parameter) is still weakly constrained by the current phenomenology. Such a constraint can be improved, however, by future data from the KamLAND experiment. In the standard MSW case, we also perform an updated analysis of two-family active oscillations of solar and reactor neutrinos

  4. Evidence for Mikheyev-Smirnov-Wolfenstein effects in solar neutrino flavor transitions

    Science.gov (United States)

    Fogli, G. L.; Lisi, E.; Marrone, A.; Palazzo, A.

    2004-03-01

    We point out that the recent data from the Sudbury Neutrino Observatory, together with other relevant measurements from solar and reactor neutrino experiments, convincingly show that the flavor transitions of solar neutrinos are affected by Mikheyev-Smirnov-Wolfenstein (MSW) effects. More precisely, one can safely reject the null hypothesis of no MSW interaction energy in matter, despite the fact that the interaction amplitude (formally treated as a free parameter) is still weakly constrained by the current phenomenology. Such a constraint can be improved, however, by future data from the KamLAND experiment. In the standard MSW case, we also perform an updated analysis of two-family active oscillations of solar and reactor neutrinos.

  5. 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)Mikheyev-Smirnov-Wolfenstein large mixing angle neutrino oscillation model is experimentally tested at low energy.

  6. Feasibility of 81Br(nu,e-)81Kr solar neutrino experiment

    International Nuclear Information System (INIS)

    Hurst, G.S.; Allman, S.L.; Chen, C.H.; Kramer, S.D.; Thomson, J.O.; Cleveland, B.

    1985-05-01

    Several ingenious solutions have been offered for the solar neutrino problem - a defect in the solar model, the appearance of a new type of neutrino physics, the sun is no longer burning, etc. The range of these proffered solutions stresses the need for a new experiment to study the sun. The modern pulsed laser now makes possible a new solar neutrino test which examines an independent neutrino source in the sun. A recently proposed experiment would use the reaction 81 Br(nu,e - ) 81 Kr to measure the flux of 7 Be neutrinos from the sun. When 7 Be decays by electron capture to make 7 Li, a neutrino is emitted at 0.862 MeV and the flux of these on the earth is about 4 x 10 9 cm -2 s -1 , according to the standard model. Therefore, an experiment based on 81 Br(nu,e - ) 81 Kr which is sensitive to these lower energy neutrinos would be of fundamental importance. To first order, the chlorine experiment detects the 8 B neutrinos while bromine detects the much more abundant 7 Be neutrino source. In practice, the proposed bromine experiment would be very similar to the chlorine radiochemical experiment, except that 81 Kr with a half-life of 2 x 10 5 years cannot be counted by decay methods. With an experiment of about the same volume as the chlorine experiment (380 m 3 ) filled with CH 2 Br 2 , the model predicts about 2 atoms of 81 Kr per day. The bromine experiment depends entirely on the RIS method, implemented with pulsed lasers, for its success. 10 refs., 3 figs

  7. The solar neutrino day/night effect in Super-Kamiokande

    International Nuclear Information System (INIS)

    Smy, Michael B.

    2005-01-01

    The time variation of the elastic scattering rate of solar neutrinos with electrons in Super-Kamiokande-I was fit to the day/night variations expected from active two-neutrino oscillations in the Large Mixing Angle region. Combining Super-Kamiokande measurements with other solar and reactor neutrino data, the mixing angle is determined as sin 2 θ=0.276 -0.026 +0.033 and the mass squared difference between the two neutrino mass eigenstates as Δm 2 =7.1 -0.5 +0.6 x10 -5 eV 2 . For the best fit parameters, a day/night asymmetry of -1.7+/-1.6(stat) -1.2 +1.3 (syst)% determined from the Super-Kamiokande data, which has improved statistical precision over previous measurements and is in excellent agreement with the expected value of -1.6%

  8. Measurement of 7Be and 8B solar neutrinos with Borexino

    International Nuclear Information System (INIS)

    Zavatarelli, S.; Bellini, G.; Bonetti, S.; Buizza-Avanzini, M.; Caccianiga, B.

    2009-01-01

    Borexino is a real-time liquid-scintillator detector for low-energy neutrino spectroscopy located at the Gran Sasso National Laboratories (Italy). Thanks to the unprecedented radio purity of the target mass it is providing the first direct and simultaneous measurements of the solar neutrino survival probability in both vacuum-dominated (7 B e ν) and matter-enhanced regions (8 B ν) by a single experiment. The measured interaction rates for both 7 B e and 8 B solar neutrinos are in fair agreement with the SSM predictions in case of the Lma-Msw oscillation solution and a further confirmation of the Lma scenario is provided by the absence of a day-night asymmetry in the 7 B e signal. These experimental results allow to improve the upper limit on the neutrino effective magnetic moment. Calibration campaigns aiming to reduce the systematical errors on fiducial volume definition and detector energy response are presently in progress.

  9. 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.

  10. On the question of the magnitude of day-night asymmetry for solar neutrinos

    International Nuclear Information System (INIS)

    Aleshin, S. S.; Lobanov, A. E.; Kharlanov, O. G.

    2013-01-01

    The effect of flavor day-night asymmetry is considered for solar neutrinos of energy about 1 MeV under the assumption that the electron-density distribution within the Earth is approximately piecewise continuous on the scale of the neutrino-oscillation length. In this approximation, the resulting asymmetry factor for beryllium neutrinos does not depend on the structure of the inner Earth’s layers or on the properties of the detector used. Its numerical estimate is on the order of −4 × 10 −4 , which is far beyond the reach of present-day experiments

  11. Matter oscillations and solar neutrinos: A review of the MSW (Mikheyev-Smirnov-Wolfenstein) effect

    Energy Technology Data Exchange (ETDEWEB)

    Rosen, S.P.; Gelb, J.M.

    1986-07-16

    We review the theory of the Mikheyev-Smirnov-Wolfenstein effect, in which matter oscillations can greatly enhance ''in vacuo'' neutrino oscillations, and we examine its consequences for the solar neutrino problem. Using a two-flavor model, we discuss the solutions in the ..delta..m/sup 2/-sin/sup 2/2THETA parameter space for the /sup 37/Cl experiment, and describe their predictions for the /sup 71/Ga experiment and for the spectrum of electron-neutrinos arriving at earth. We also comment on the three-flavor case.

  12. Matter oscillations and solar neutrinos: A review of the MSW [Mikheyev-Smirnov-Wolfenstein] effect

    International Nuclear Information System (INIS)

    Rosen, S.P.; Gelb, J.M.

    1986-01-01

    We review the theory of the Mikheyev-Smirnov-Wolfenstein effect, in which matter oscillations can greatly enhance ''in vacuo'' neutrino oscillations, and we examine its consequences for the solar neutrino problem. Using a two-flavor model, we discuss the solutions in the Δm 2 -sin 2 2Θ parameter space for the 37 Cl experiment, and describe their predictions for the 71 Ga experiment and for the spectrum of electron-neutrinos arriving at earth. We also comment on the three-flavor case

  13. Search for the solar pp-neutrinos with an upgrade of CTF detector

    International Nuclear Information System (INIS)

    Smirnov, O.Yu.; Zajmidoroga, O.A.; Derbin, A.V.

    2001-01-01

    A possibility to use ultrapure liquid organic scintillator as a low energy solar neutrino detector is discussed. The detector with an active volume of 10 tons and 4π coverage will count 1.8 pp-neutrinos and 5.4 7 Be neutrinos per day with an energy threshold of 170 keV for the recoil electrons. The evaluation of the detector sensitivity and backgrounds is based on the results obtained by the Borexino collaboration with the Counting Test Facility (CTF). The detector can be build at the Italian Gran Sasso underground laboratory as an upgrade of the CTF detector using already developed technologies

  14. Solar Mikheyev-Smirnov-Wolfenstein Effect with Three Generations of Neutrinos

    OpenAIRE

    Osland, P; Wu Tai Tsun

    1999-01-01

    Under the assumption that the density variation of the electrons can be approximated by an exponential function, the solar Mikheyev-Smirnov-Wolfenstein effect is treated for three generations of neutrinos. The generalized hypergeometric functions that result from the exact solution of this problem are studied in detail, and a method for their numerical evaluation is presented. This analysis plays a central role in the determination of neutrino masses, not only the differences of their squares...

  15. Mirror model for sterile neutrinos

    International Nuclear Information System (INIS)

    Berezinsky, Veniamin; Narayan, Mohan; Vissani, Francesco

    2003-01-01

    Sterile neutrinos are studied as subdominant contribution to solar neutrino physics. The mirror-matter neutrinos are considered as sterile neutrinos. We use the symmetric mirror model with gravitational communication between mirror and visible sectors. This communication term provides mixing between visible and mirror neutrinos with the basic scale μ=v EW 2 /M Pl =2.5x10 -6 eV, where v EW =174 GeV is the vacuum expectation value of the standard electroweak group and M Pl is the Planckian mass. It is demonstrated that each mass eigenstate of active neutrinos splits into two states separated by small Δm 2 . Unsuppressed oscillations between active and sterile neutrinos (ν a ↔ν s ) occur only in transitions between each of these close pairs ('windows'). These oscillations are characterized by very small Δm 2 and can suppress the flux and distort spectrum of pp-neutrinos in detectable way. The other observable effect is anomalous seasonal variation of neutrino flux, which appears in LMA solution. The considered subdominant neutrino oscillations ν a ↔ν s can reveal itself as big effects in observations of supernova neutrinos and high-energy (HE) neutrinos. In the case of HE neutrinos they can provide a very large diffuse flux of active neutrinos unconstrained by the e-m cascade upper limit

  16. Short-time variations of the solar neutrino luminosity (Fourier analysis of the argon-37 production rate data)

    International Nuclear Information System (INIS)

    Haubold, H.J.; Gerth, E.

    1985-01-01

    We continue the Fourier analysis of the argon-37 production rate for runs 18--80 observed in Davis' well known solar neutrino experiment. The method of Fourier analysis with the unequally-spaced data of Davis and associates is described and the discovered periods we compare with our recently published results for the analysis of runs 18--69 (Haubold and Gerth, 1983). The harmonic analysis of the data of runs 18--80 shows time variations of the solar neutrino flux with periods π = 8.33; 5.26; 2.13; 1.56; 0.83; 0.64; 0.54; and 0.50 years, respectively, which confirms our earlier computations

  17. Measurement of solar proton-proton fusion neutrinos with a Soviet-American gallium experiment: Technical progress report

    International Nuclear Information System (INIS)

    Cherry, M.L.

    1989-06-01

    A gallium solar neutrino detector is sensitive to low-energy proton-proton fusion neutrinos. A flux of 70 SNU is expected in a gallium detector from the p-p reaction independent of solar model calculations. If, however, neutrino oscillations in the solar interior are responsible for the suppressed 8 B flux measured by the Homestake 37 Cl experiment, then a comparison of the gallium and chlorine results may make possible a determination of the neutrino mass difference and mixing angle. A 60-ton gallium detector is currently being constructed in the Baksan Laboratory in the Soviet Union, and should be taking data by the end of 1989

  18. Solar and atmospheric neutrinos in three generations with a magnetic moment

    International Nuclear Information System (INIS)

    Pulido, J.; Tao, Z.

    1995-01-01

    A solution to the solar and atomospheric neutrino problems in three generations in the joint context of matter oscillations and the magnetic moment is investigated. An appropriate rotation of the evolution Hamiltonian reduces the three generation case to a two generation one. A convenient background for such a scenario with small neutrino masses and large magnetic moments is given by the Zee-type models, in which the mass generation mechanism leads to a pair of separate orders of magnitude for the mass square differences between neutrino species. We obtain a ratio var-epsilon congruent 10 -2 --10 -3 between these orders of magnitude, so that one of them [(0.3--3)x10 -2 eV 2 ] is suitable for the atmospheric neutrino solution and the other (∼10 -5 eV 2 ) for the solar neutrino solution. The magnetic moment leads to a decrease of the survival probability with solar neutrino energy. Such a decrease is consistent with the experimental situation

  19. Testing the very-short-baseline neutrino anomalies at the solar sector

    Science.gov (United States)

    Palazzo, Antonio

    2011-06-01

    Motivated by the accumulating hints of new sterile neutrino species at the eV scale, we explore the consequences of such an hypothesis on the solar sector phenomenology. After introducing the theoretical formalism needed to describe the Mikheyev-Smirnov-Wolfenstein conversion of solar neutrinos in the presence of one (or more) sterile neutrino state(s) located “far” from the (ν1, ν2) “doublet”, we perform a quantitative analysis of the available experimental results, focusing on the electron neutrino mixing. We find that the present data posses a sensitivity to the amplitude of the lepton mixing matrix element Ue4—encoding the admixture of the electron neutrino with a new mass eigenstate—which is comparable to that achieved on the standard matrix element Ue3. In addition, and more importantly, our analysis evidences that, in a 4-flavor framework, the current preference for |Ue3|≠0 is indistinguishable from that for |Ue4|≠0, having both a similar statistical significance (which is ˜1.3σ adopting the old reactor fluxes determinations, and ˜1.8σ using their new estimates.) We also point out that, differently from the standard 3-flavor case, in a 3+1 scheme the Dirac CP-violating phases cannot be eliminated from the description of solar neutrino conversions.

  20. Measurement of the solar neutrino capture rate with gallium metal. III. Results for the 2002-2007 data-taking period

    International Nuclear Information System (INIS)

    Abdurashitov, J. N.; Gavrin, V. 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. 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 keV of 65.4 -3.0 +3.1 (stat) -2.8 +2.6 (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 37 Ar neutrino source. The ratio of observed to calculated rates in this experiment, combined with the measured rates in the three prior 51 Cr neutrino-source experiments with Ga, is 0.87±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 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 SNU to 66 SNU with an uncertainty of about 4%, in good agreement with experiment. We derive the current value of the neutrino flux produced in the Sun by the proton-proton fusion reaction to be φ pp · =(6.0±0.8)x10 10 /(cm 2 s), which agrees well with the pp 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.

  1. Day-night effect in solar neutrino oscillations with three flavors

    International Nuclear Information System (INIS)

    Blennow, Mattias; Ohlsson, Tommy; Snellman, Haakan

    2004-01-01

    We investigate the effects of a nonzero leptonic mixing angle θ 13 on the solar neutrino day-night asymmetry. Using a constant matter density profile for the Earth and well-motivated approximations, we derive analytical expressions for the ν e survival probabilities for solar neutrinos arriving directly at the detector and for solar neutrinos which have passed through the Earth. Furthermore, we numerically study the effects of a nonzero θ 13 on the day-night asymmetry at detectors and find that they are small. Finally, we show that if the uncertainties in the parameters θ 12 and Δm 2 as well as the uncertainty in the day-night asymmetry itself were much smaller than they are today, this effect could, in principle, be used to determine θ 13

  2. Solar neutrino oscillation parameters after SNO Phase-III and SAGE Part-III

    International Nuclear Information System (INIS)

    Yang Ping; Liu Qiuyu

    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 θ 12 . Through a global analysis using all existing data from SK, SNO, Ga and Cl radiochemical experiments and long base line reactor experiment KamLAND , we obtain the parameters Δm 12 2 =7.684 -0.208 +0.212 x 10 -5 eV 2 , tan 2 θ 12 =0.440 -0.057 +0.059 . 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 θ 13 . (authors)

  3. 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.

  4. Observational constraints on secret neutrino interactions from big bang nucleosynthesis

    Science.gov (United States)

    Huang, Guo-yuan; Ohlsson, Tommy; Zhou, Shun

    2018-04-01

    We investigate possible interactions between neutrinos and massive scalar bosons via gϕν ¯ν ϕ (or massive vector bosons via gVν ¯γμν Vμ) and explore the allowed parameter space of the coupling constant gϕ (or gV) and the scalar (or vector) boson mass mϕ (or mV) by requiring that these secret neutrino interactions (SNIs) should not spoil the success of big bang nucleosynthesis (BBN). Incorporating the SNIs into the evolution of the early Universe in the BBN era, we numerically solve the Boltzmann equations and compare the predictions for the abundances of light elements with observations. It turns out that the constraint on gϕ and mϕ in the scalar-boson case is rather weak, due to a small number of degrees of freedom (d.o.f.). However, in the vector-boson case, the most stringent bound on the coupling gV≲6 ×10-10 at 95% confidence level is obtained for mV≃1 MeV , while the bound becomes much weaker gV≲8 ×10-6 for smaller masses mV≲10-4 MeV . Moreover, we discuss in some detail how the SNIs affect the cosmological evolution and the abundances of the lightest elements.

  5. Integral method of treatment of experimental data from radiochemical solar neutrino detectors

    International Nuclear Information System (INIS)

    Gavrin, V.N.; Kopylov, A.V.; Streltsov, A.V.

    1985-01-01

    An analysis is made of the statistical errors in solar neutrino detection by radiochemical detectors at different times of exposure. It is shown that short exposures (tau/sub e/ = one-half to one half-life) give minimal one-year error. The possibility is considered of the detection of the solar neutrino flux variation due to annual changes of the Earth-Sun distance. The integral method of treatment of the experimental data is described. Results are given of the statistical treatment of computer simulated data

  6. Neutrino mass?

    International Nuclear Information System (INIS)

    Kayser, B.

    1992-01-01

    After arguing that we should be looking for evidence of neutrino mass, we illustrate the possible consequences of neutrino mass and mixing. We then turn to the question of whether neutrinos are their own antiparticles, and to the process which may answer this question: neutrinoless double beta decay. Next, we review the proposed Mikheyev-Smirnov-Wolfenstein solution to the solar neutrino problem, and discuss models which can generate neutrino electromagnetic moments large enough to play a role in the sun. Finally, we consider how the possible 17 keV neutrino, if real, would fit in with everything we know about neutrinos. (orig.)

  7. Research and development of a helium-4 based solar neutrino detector

    International Nuclear Information System (INIS)

    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

  8. Determination of neutrino mass hierarchy by 21 cm line and CMB B-mode polarization observations

    Energy Technology Data Exchange (ETDEWEB)

    Oyama, Yoshihiko, E-mail: oyamayo@post.kek.jp [The Graduate University for Advanced Studies (SOKENDAI), 1-1 Oho, Tsukuba 305-0801 (Japan); Shimizu, Akie [The Graduate University for Advanced Studies (SOKENDAI), 1-1 Oho, Tsukuba 305-0801 (Japan); Kohri, Kazunori [The Graduate University for Advanced Studies (SOKENDAI), 1-1 Oho, Tsukuba 305-0801 (Japan); Institute of Particle and Nuclear Studies, KEK, 1-1 Oho, Tsukuba 305-0801 (Japan)

    2013-01-29

    We focus on the ongoing and future observations for both the 21 cm line and the CMB B-mode polarization produced by a CMB lensing, and study their sensitivities to the effective number of neutrino species, the total neutrino mass, and the neutrino mass hierarchy. We find that combining the CMB observations with future square kilometer arrays optimized for 21 cm line such as Omniscope can determine the neutrino mass hierarchy at 2{sigma}. We also show that a more feasible combination of Planck + POLARBEAR and SKA can strongly improve errors of the bounds on the total neutrino mass and the effective number of neutrino species to be {Delta}{Sigma}m{sub {nu}}{approx}0.12 eV and {Delta}N{sub {nu}}{approx}0.38 at 2{sigma}, respectively.

  9. 37Ar based neutron source for calibration of the iodine solar neutrino detector

    International Nuclear Information System (INIS)

    Abdurashitov, D.N.; Gavrin, V.N.; Mirmov, I.N.; Veretenkin, E.P.; Yants, V.Eh.; Cleveland, B.T.; Davis, R. Jr.; Lande, K.; Wildenhain, P.; Khomyakov, Yu.S.

    2001-01-01

    The methodology of the creation of a compact neutrino source based on the 37 Ar isotope as well as the technique of calibration of an iodine detector of solar neutrinos is described. An important overall expected result is the creation of a prototype of the source with the intensity up to 400 kCi, delivery of this source to the Baksan neutrino observatory and the test calibration of the single module of the iodine detector. Simulation shows that at least 45-70 127 Xe atoms will be detected in the irradiation of ∼40 tons of methylene iodide by the source leading to ∼19% of the error on the measured production rate. This result should be considered as a test of the developed technology and will verify overall technical readiness for the creation of a full scale neutrino source and the full scale calibration of the iodine detector

  10. Neutrino hierarchy from CP-blind observables with high density magnetized detectors

    International Nuclear Information System (INIS)

    Donini, A.; Fernandez-Martinez, E.; Rigolin, S.; Migliozzi, P.; Scotto Lavina, L.; Selvi, M.; Tabarelli de Fatis, T.; Terranova, F.

    2008-01-01

    High density magnetized detectors are well suited to exploit the outstanding purity and intensities of novel neutrino sources like neutrino factories and beta beams. They can also provide independent measurements of leptonic mixing parameters through the observation of atmospheric muon-neutrinos. In this paper, we discuss the combination of these observables from a multi-kT iron detector and a high energy beta beam; in particular, we demonstrate that even with moderate detector granularities the neutrino mass hierarchy can be determined for θ 13 values greater than 4 . (orig.)

  11. Neutrino physics with JUNO

    Science.gov (United States)

    An, Fengpeng; An, Guangpeng; An, Qi; Antonelli, Vito; Baussan, Eric; Beacom, John; Bezrukov, Leonid; Blyth, Simon; Brugnera, Riccardo; Buizza Avanzini, Margherita; 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, Hervé; 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; Göger-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, Cécile; 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; Möllenberg, 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, Yi; Wang, Yifang; Wang, Zhe; Wang, Zheng; Wang, Zhigang; Wang, Zhimin; Wei, Wei; Wen, Liangjian; Wiebusch, Christopher; Wonsak, Björn; 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, Frédéric; 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

    2016-03-01

    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 (MH) as a primary physics goal. The excellent energy resolution and the large fiducial volume anticipated for the JUNO detector offer exciting opportunities for addressing many important topics in neutrino and astro-particle physics. In this document, we present the physics motivations and the anticipated performance of the JUNO detector for various proposed measurements. Following an introduction summarizing the current status and open issues in neutrino physics, we discuss how the detection of antineutrinos generated by a cluster of nuclear power plants allows the determination of the neutrino MH at a 3-4σ significance with six years of running of JUNO. The measurement of antineutrino spectrum with excellent energy resolution will also lead to the precise determination of the neutrino oscillation parameters {{sin}}2{θ }12, {{Δ }}{m}212, and | {{Δ }}{m}{ee}2| to an accuracy of better than 1%, which will play a crucial role in the future unitarity test of the MNSP matrix. The JUNO detector is capable of observing not only antineutrinos from the power plants, but also neutrinos/antineutrinos from terrestrial and extra-terrestrial sources, including supernova burst neutrinos, diffuse supernova neutrino background, geoneutrinos, atmospheric neutrinos, and solar neutrinos. As a result of JUNO's large size, excellent energy resolution, and vertex reconstruction capability, interesting new data on these topics can be collected. For example, a neutrino burst from a typical core-collapse supernova at a distance of 10 kpc would lead to ˜5000 inverse-beta-decay events and ˜2000 all-flavor neutrino-proton ES events in JUNO, which are of crucial importance for understanding the mechanism of supernova explosion and for exploring novel phenomena such as collective neutrino oscillations

  12. Identifying the neutrino mass spectrum from a supernova neutrino burst

    International Nuclear Information System (INIS)

    Dighe, A.S.; Smirnov, A.Yu.

    1999-12-01

    We study the role that the future detection of the neutrino burst from a galactic supernova can play in the reconstruction of the neutrino mass spectrum. We consider all possible 3ν mass and flavor spectra which describe the solar and atmospheric neutrino data. For each of these spectra we find the observable effects of the supernova neutrino conversions both in the matter of the star and the earth. We show that studies of the electron neutrino and antineutrino spectra as well as observations of the neutral current effects from supernova will allow us (i) to identify the solar neutrino solution, (ii) to determine the type of mass hierarchy (normal or inverted) and (iii) to probe the mixing vertical bar U e3 vertical bar 2 to values as low as 10 -4 - 10 -3 . (author)

  13. AMANDA Observations Constrain the Ultrahigh Energy Neutrino Flux

    Energy Technology Data Exchange (ETDEWEB)

    Halzen, Francis; /Wisconsin U., Madison; Hooper, Dan; /Fermilab

    2006-05-01

    A number of experimental techniques are currently being deployed in an effort to make the first detection of ultra-high energy cosmic neutrinos. To accomplish this goal, techniques using radio and acoustic detectors are being developed, which are optimally designed for studying neutrinos with energies in the PeV-EeV range and above. Data from the AMANDA experiment, in contrast, has been used to place limits on the cosmic neutrino flux at less extreme energies (up to {approx}10 PeV). In this letter, we show that by adopting a different analysis strategy, optimized for much higher energy neutrinos, the same AMANDA data can be used to place a limit competitive with radio techniques at EeV energies. We also discuss the sensitivity of the IceCube experiment, in various stages of deployment, to ultra-high energy neutrinos.

  14. Neutrino masses in astrophysics and cosmology

    International Nuclear Information System (INIS)

    Raffelt, G.G.

    1996-01-01

    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

  15. 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.

  16. 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.

  17. Search for cold dark matter and solar neutrinos with GENIUS and GENIUS-TF

    International Nuclear Information System (INIS)

    Krivosheina, I.V.

    2002-01-01

    The new project GENIUS will cover a wide range of the parameter space of predictions of supersymmetry for neutralinos as cold dark matter. Further, it has the potential to be a real-time detector for low-energy (pp and 7 Be) solar neutrinos. The GENIUS Test Facility has just been funded and will come into operation by the end of 2001

  18. Search for cold dark matter and solar neutrinos with GENIUS and GENIUS-TF

    International Nuclear Information System (INIS)

    Krivosheina, I.V.

    2002-01-01

    The new project GENIUS will cover a wide range of the parameter space of predictions of supersymmetry for neutralinos as cold dark matter. Further it has the potential to be a real-time detector for low-energy (pp and 7 Be) solar neutrinos. The GENIUS Test Facility has just been funded and will come into operation by the end of 2001 [ru

  19. Progress Report: Feasibility Study of an Indium Scintillator Solar Neutrino Experiment

    International Nuclear Information System (INIS)

    Bellefon, A. de; Barloutaud, R.; Borg, A.; Ernwein, J.; Mosca, L.

    1989-09-01

    In this document, we report on the progress made to demonstrate the feasibility of an experiment which would measure for the first time the two line sources of solar neutrinos resulting from electron capture by 7 Be and from the p-e-p reaction inside the sun. The detector under study consists of scintillator containing 10 tons of Indium

  20. A semi-analytical computation of the theoretical uncertainties of the solar neutrino flux

    DEFF Research Database (Denmark)

    Jorgensen, Andreas C. S.; Christensen-Dalsgaard, Jorgen

    2017-01-01

    We present a comparison between Monte Carlo simulations and a semi-analytical approach that reproduces the theoretical probability distribution functions of the solar neutrino fluxes, stemming from the pp, pep, hep, Be-7, B-8, N-13, O-15 and F-17 source reactions. We obtain good agreement between...

  1. Solar polarimetry: observations and theories

    Energy Technology Data Exchange (ETDEWEB)

    Rees, D E [Sydney Univ. (Australia). Dept. of Applied Mathematics

    1982-01-01

    This review surveys some recent observations of polarization in solar spectral lines with emphasis on their theoretical interpretation. Observations of non-magnetic resonance line polarization offer a new approach to temperature and density modelling of the atmosphere. They also provide a basis for comparison in Hanle effect studies of weak magnetic fields on the solar disk. Measurements of the Hanle effect are being used to deduce vector magnetic fields in prominences. It is now feasible to try to infer the vector field distribution in an active region such as a sunspot from analysis of the stokes parameter profiles of a Zeeman split line.

  2. Addendum to: ''The SNO solar neutrino data, neutrinoless double beta-decay and neutrino mass spectrum'' [Phys. Lett. B 544 (2002) 239

    International Nuclear Information System (INIS)

    Pascoli, S.; Petcov, S.T.

    2004-01-01

    We update our earlier study [Phys. Lett. B 544 (2002) 239], which was inspired by the 2002 SNO data, on the implications of the results of the solar neutrino experiments for the predictions of the effective Majorana mass in neutrinoless double beta-decay, vertical bar vertical bar. We obtain predictions for vertical bar vertical bar using the values of the neutrino oscillation parameters, obtained in the analyzes of the presently available solar neutrino data, including the just published data from the salt phase of the SNO experiment, the atmospheric neutrino and CHOOZ data and the first data from the KamLAND experiment. The main conclusion reached in the previous study [Phys. Lett. B 544 (2002) 239] of the existence of significant lower bounds on vertical bar vertical bar in the cases of neutrino mass spectrum of inverted hierarchical (IH) and quasi-degenerate (QD) type is strongly reinforced by fact that combined solar neutrino data (i) exclude the possibility of cos2θ o =0 at more than 5 s.d., (ii) determine as a best fit value cos2θ o =0.40, and (iii) imply at 95% C.L. that cos2θ o ∼>0.22, θ o being the solar neutrino mixing angle. For the IH and QD spectra we get using, e.g., the 90% C.L. allowed ranges of values of the oscillation parameters, vertical bar vertical bar ∼>0.010 eV and vertical bar vertical bar ∼>0.043 eV, respectively. We also comment on the possibility to get information on the neutrino mass spectrum and on the CP-violation in the lepton sector due to Majorana CP-violating phases

  3. Observation of the last, weakest neutrino transformation at RENO

    CERN Multimedia

    CERN. Geneva

    2012-01-01

    The RENO experiment has observed the disappearance of reactor electron antineutrinos, consistent with neutrino oscillations, with a significance of 4.9 standard deviations. Antineutrinos from six reactors at Yonggwang Nuclear Power Plant in Korea, are detected by two identical detectors located at 294 m and 1383 m, respectively, from the reactor array center. In the 229 day data-taking period of 11 August 2011 to 26 March 2012, the far (near) detector observed 17102 (154088) electron antineutrino candidate events with a background fraction of 5.5% (2.7%). A ratio of observed to expected number of antineutrinos in the far detector is 0.920+-0.009(stat.)+-0.014(syst.). From the deficit, we find sin^2(2theta_13)=0.113+-0.013(stat.)+-0.019(syst,) based on a rate-only analysis. In this talk, we will describe experimental setup, data taking, data analysis, and results for the measurement of theta_13.

  4. Neutrino mass, a status report

    International Nuclear Information System (INIS)

    Robertson, R.G.H.

    1993-01-01

    Experimental approaches to neutrino mass include kinematic mass measurements, neutrino oscillation searches at rectors and accelerators, solar neutrinos, atmospheric neutrinos, and single and double beta decay. The solar neutrino results yield fairly strong and consistent indications that neutrino oscillations are occurring. Other evidence for new physics is less consistent and convincing

  5. Neutrino astrophysics

    International Nuclear Information System (INIS)

    Roulet, E.

    2001-01-01

    A general overview of neutrino physics and astrophysics is given, starting with a historical account of the development of our understanding of neutrinos and how they helped to unravel the structure of the Standard Model. We discuss why it is so important to establish if neutrinos are massive and introduce the main scenarios to provide them a mass. The present bounds and the positive indications in favor of non-zero neutrino masses are discussed, including the recent results on atmospheric and solar neutrinos. The major role that neutrinos play in astrophysics and cosmology is illustrated. (author)

  6. Environmental 222Rn as a background source in the solar neutrino experiment GALLEX

    International Nuclear Information System (INIS)

    Wojcik, M.

    1996-01-01

    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

  7. Solar neutrino masses and mixing from bilinear R-parity broken supersymmetry: Analytical versus numerical results

    Science.gov (United States)

    Díaz, M.; Hirsch, M.; Porod, W.; Romão, J.; Valle, J.

    2003-07-01

    We give an analytical calculation of solar neutrino masses and mixing at one-loop order within bilinear R-parity breaking supersymmetry, and compare our results to the exact numerical calculation. Our method is based on a systematic perturbative expansion of R-parity violating vertices to leading order. We find in general quite good agreement between the approximate and full numerical calculations, but the approximate expressions are much simpler to implement. Our formalism works especially well for the case of the large mixing angle Mikheyev-Smirnov-Wolfenstein solution, now strongly favored by the recent KamLAND reactor neutrino data.

  8. Solar Mikheyev-Smirnov-Wolfenstein effect with three generations of neutrinos

    International Nuclear Information System (INIS)

    Osland, Per; Wu, Tai Tsun

    2000-01-01

    Under the assumption that the density variation of the electrons can be approximated by an exponential function, the solar Mikheyev-Smirnov-Wolfenstein effect is treated for three generations of neutrinos. The generalized hypergeometric functions that result from the exact solution of this problem are studied in detail, and a method for their numerical evaluation is presented. This analysis plays a central role in the determination of neutrino masses, not only the differences of their squares, under the assumption of universal quark-lepton mixing. (c) 2000 The American Physical Society

  9. 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.

  10. 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,

    1997-12-31

    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.

  11. Understanding neutrino masses and mixings

    Indian Academy of Sciences (India)

    various possible oscillation solutions to the solar neutrino puzzle. It seems .... A first hint of this new ingredient came from the observation of Weinberg that if ..... Using the discussion of the above paragraph, the Dirac mass of the neutrino as .... that contributes to charged fermion masses, one can write the quark and lepton.

  12. Corrections to the Predicitions for Atmospheric Neutrino Observations

    OpenAIRE

    Poirier, J.

    2000-01-01

    The theoretical Monte Carlo calculations of the production of neutrinos via cosmic rays incident upon the earth's atmosphere are examined. The calculations are sensitive to the assumed ratio of pi+ / pi- production cross sections; this ratio appears to be underestimated in the theory relative to the experimentally measured ratio. Since the neutrino detection cross section is three times larger than that for the antineutrino, the theoretical predicted detection ratio (nu_mu / nu_e) is correspo...

  13. Do astrophysical measurements suggest massive neutrinos?

    International Nuclear Information System (INIS)

    Ali, M.; Fazal-e-Aleem; Rashid, H.

    1996-01-01

    We discuss the solar neutrino puzzle and suggest modification in the standard solar model. It has been observed that the discrepancy between experimental measurements and theoretically produced values can be removed by considering neutrinos to process non-zero mass. (author)

  14. Numerical computation of solar neutrino flux attenuated by the MSW mechanism

    Science.gov (United States)

    Kim, Jai Sam; Chae, Yoon Sang; Kim, Jung Dae

    1999-07-01

    We compute the survival probability of an electron neutrino in its flight through the solar core experiencing the Mikheyev-Smirnov-Wolfenstein effect with all three neutrino species considered. We adopted a hybrid method that uses an accurate approximation formula in the non-resonance region and numerical integration in the non-adiabatic resonance region. The key of our algorithm is to use the importance sampling method for sampling the neutrino creation energy and position and to find the optimum radii to start and stop numerical integration. We further developed a parallel algorithm for a message passing parallel computer. By using an idea of job token, we have developed a dynamical load balancing mechanism which is effective under any irregular load distributions

  15. Unified fit of solar and atmospheric neutrinos: towards the MNSP matrix

    International Nuclear Information System (INIS)

    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)

  16. What can be learned with an iodine solar-neutrino detector?

    International Nuclear Information System (INIS)

    Engel, J.; Krastev, P.I.; Lande, K.

    1995-01-01

    We study the potential benefits of an iodine-based solar-neutrino detector for testing hypotheses that involve neutrino oscillations. We argue that such a detector will have a good chance of distinguishing the two allowed regions of Δm 2 -sin 2 2θ parameter space if neutrino conversion is occurring in the Sun. It should also be able to detect seasonal variations in the signal due to vacuum oscillations and might be sensitive enough to detect day/night variations due to MSW transitions in the earth. Although it would need to be calibrated, a working iodine detector could be completed long before more ambitious projects that seek to accomplish the same things

  17. Solar radio observations and interpretations

    International Nuclear Information System (INIS)

    Rosenberg, H.

    1976-01-01

    The recent solar radio observations related to flares are reviewed for the frequency range of a few kilohertz to several gigahertz. The analysis of the radio data leads to boundary conditions on the acceleration processes which are responsible for the fast particles which cause radio emission. The role and cause of plasma turbulence at the plasma-frequency and at much lower frequencies is discussed in relation to the acceleration processes and the radio emission mechanisms for the various radio bursts. (author)

  18. AGN outflows as neutrino sources: an observational test

    Science.gov (United States)

    Padovani, P.; Turcati, A.; Resconi, E.

    2018-04-01

    We test the recently proposed idea that outflows associated with Active Galactic Nuclei (AGN) could be neutrino emitters in two complementary ways. First, we cross-correlate a list of 94 "bona fide" AGN outflows with the most complete and updated repository of IceCube neutrinos currently publicly available, assembled by us for this purpose. It turns out that AGN with outflows matched to an IceCube neutrino have outflow and kinetic energy rates, and bolometric powers larger than those of AGN with outflows not matched to neutrinos. Second, we carry out a statistical analysis on a catalogue of [O III] λ5007 line profiles using a sample of 23,264 AGN at z values (˜6 and 18 per cent respectively, pre-trial) for relatively high velocities and luminosities. Our results are consistent with a scenario where AGN outflows are neutrino emitters but at present do not provide a significant signal. This can be tested with better statistics and source stacking. A predominant role of AGN outflows in explaining the IceCube data appears in any case to be ruled out.

  19. Neutrino 2004: Collection of Presentations

    International Nuclear Information System (INIS)

    2004-01-01

    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

  20. 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.

  1. Experimental neutrino physics

    CERN Document Server

    Link, Jonathan M

    2018-01-01

    Neutrinos have a smaller mass than any other known particle and are the subject of intense recent studies, as well as this book. The author provides a coherent introduction to the necessary theoretical background and experimental methods used by modern neutrino physicists. It’s designed as a one-stop reference addressing what is currently known about the neutrino hypothesis, discovery of the neutrino, theory of weak interactions, solar neutrino puzzle, and neutrino oscillation. It then gives a detailed account of practical approaches for study of precision oscillations, neutrino mass and other neutrino properties, sterile neutrinos, and neutrino messengers from space and Earth’s interior.

  2. CNO neutrino Grand Prix: the race to solve the solar metallicity problem

    Science.gov (United States)

    Cerdeño, David G.; Davis, Jonathan H.; Fairbairn, Malcolm; Vincent, Aaron C.

    2018-04-01

    Several next-generation experiments aim to make the first measurement of the neutrino flux from the Carbon-Nitrogen-Oxygen (CNO) solar fusion cycle. We calculate how much time these experiments will need to run for in order to measure this flux with enough precision to tell us the metal content of the Sun's core, and thereby help to solve the solar metallicity problem. For experiments looking at neutrino-electron scattering, we find that SNO+ will measure this CNO neutrino flux with enough precision after five years in its pure scintillator mode, provided its 210Bi background is measured to 1% accuracy. By comparison, a 100 ton liquid argon experiment such as Argo will take ten years in Gran Sasso lab, or five years in SNOLAB or Jinping. Borexino could obtain this precision in ten years, but this projection is very sensitive to background assumptions. For experiments looking at neutrino-nucleus scattering, the best prospects are obtained for low-threshold solid state detectors (employing either germanium or silicon). These would require new technologies to lower the experimental threshold close to detection of single electron-hole pairs, and exposures beyond those projected for next-generation dark matter detectors.

  3. Solar Observations at Submillimeter Wavelengths

    Science.gov (United States)

    Kaufmann, P.

    We review earlier to recent observational evidences and theoretical motivations leading to a renewed interest to observe flares in the submillimeter (submm) - infrared (IR) range of wavelengths. We describe the new solar dedicated submillimeter wave telescope which began operations at El Leoncito in the Argentina Andes: the SST project. It consists of focal plane arrays of two 405 GHz and four 212 GHz radiometers placed in a 1.5-m radome-enclosed Cassegrain antenna, operating simultaneously with one millisecond time resolution. The first solar events analyzed exhibited the onset of rapid submm-wave spikes (100-300 ms), well associated to other flare manifestations, especially at X-rays. The spikes positions were found scattered over the flaring source by tens of arcseconds. For one event an excellent association was found between the gamma-ray emission time profile and the rate of occurrence of submm-wave rapid spikes. The preliminary results favour the idea that bulk burst emissions are a response to numerous fast energetic injections, discrete in time, produced at different spatial positions over the flaring region. Coronal mass ejections were associated to the events studied. Their trajectories extrapolated to the solar surface appear to correspond to the onset time of the submm-wave spikes, which might represent an early signature of the CME's initial acceleration process.

  4. Neutrino masses and mixing

    International Nuclear Information System (INIS)

    Fogli, G.

    1998-01-01

    The paper presents an analysis of the solar neutrino problem in terms of both Mikheyev-Smirnov-Wolfenstein (MSW) and vacuum neutrino oscillations, with the inclusion of the data collected by the SuperKamiokande experiment during 306.3 days of operation. In particular, the observed energy spectrum of the recoil electrons from 8 B neutrino scattering is discussed in detail and used to constrain the mass-mixing parameter space. Going to the atmospheric neutrino anomaly, the paper performs both a two- and three-flavor analysis of the most recent SuperKamiokande atmospheric neutrino data. The variations of the zenith distributions of ν events in the presence of flavor oscillations are investigated. It is seen that fits to the SK data, with and without the addition of the CHOOZ constrains, strongly limit the parameter space. Detailed bounds in triangle graphs are reported

  5. Low Energy 8 B Solar Neutrinos with the Wideband Intelligent Trigger at Super-Kamiokande

    Science.gov (United States)

    Elnimr, Muhammad; Super-Kamiokande Collaboration

    2017-09-01

    The water Cherenkov experiment Super-Kamiokande (SK) has accumulated a sample of ˜ 90k solar neutrino data in the past two decades. Currently, the detector measures recoil electrons from solar 8 B neutrino-electron scattering above a kinetic energy of ˜ 3.5 MeV, limited by the capacity of the software trigger, although electrons as low as 2.5 MeV can be reconstructed. The next frontier for the low energy program at Super-K is the current operation of the Wideband Intelligent Trigger (WIT) to push the trigger threshold to the event reconstruction limit of 2.5 MeV. This opens up the possibility to explore the lower energy edge of the Mikheyev-Smirnov-Wolfenstein (MSW) effect in the sun. In this work we will present the prelimiary analysis of the accumlated WIT data taken so far as well as future prospects.

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

    International Nuclear Information System (INIS)

    Guo, Wan-Lei

    2016-01-01

    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 + τ − , b b-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 + τ − 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 + τ − 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

  7. 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.)

  8. The miniaturized proportional counter HD-2(Fe)/(Si) for the GALLEX solar neutrino experiment

    Energy Technology Data Exchange (ETDEWEB)

    Wink, R.; Anselmann, P.; Doerflinger, D.; Hampel, W.; Heusser, G.; Kirsten, T.; Moegel, P.; Pernicka, E.; Plaga, R.; Schlosser, C. (Max Planck Inst. fuer Kernphysik, Heidelberg (Germany))

    1993-06-01

    The miniaturized proportional counters used for the detection of [sup 71]Ge in the solar neutrino project GALLEX are characterized. We also report on the construction techniques applied to build these counters and to achieve the described performance. A very low counting background is achieved by, among other things, careful selection of the materials used for construction. The total [sup 71]Ge detection efficiency after applying cuts to reduce the background is about 66%. (orig.).

  9. The fluid-filling 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.

    2009-09-01

    The system for controlled filling of the nested flexible scintillator containment vessels in the Borexino solar neutrino detector is described. The design and operation principles of pressure and shape monitoring systems are presented for gas filling, gas displacement by water, and water displacement by scintillator. System specifications for safety against overstressing the flexible nylon vessels are defined as well as leak-tightness and cleanliness requirements. The fluid-filling system was a major engineering challenge for the Borexino detector.

  10. Solar Mikheyev-Smirnov-Wolfenstein Effect with Three Generations of Neutrinos

    CERN Document Server

    Osland, P; Osland, Per; Wu, Tai Tsun

    2000-01-01

    Under the assumption that the density variation of the electrons can beapproximated by an exponential function, the solar Mikheyev-Smirnov-Wolfensteineffect is treated for three generations of neutrinos. The generalizedhypergeometric functions that result from the exact solution of this problemare studied in detail, and a method for their numerical evaluation ispresented. This analysis plays a central role in the determination of neutrinomasses, not only the differences of their squares, under the assumption ofuniversal quark-lepton mixing.

  11. Effects of resonant matter oscillation in earth on solar neutrino detection

    International Nuclear Information System (INIS)

    Hiroi, Shinichi; Sakuma, Hiroko; Yanagida, Tsutomu; Yoshimura, Motohiko.

    1987-01-01

    A systematic study of the Mikheyev-Smirnov-Wolfenstein (MSW) effect in earth is carried out on the solar neutrino flux from 8 B decay. In Kamiokande type detectors day-night difference of rates, seasonal variation and recoil electron spectrum are found to be good indicators of the earth effect for a range of mixing parameters around δm 2 = 3 x 10 -6 ev 2 and sin 2 2θ = 0.2. (author)

  12. The Coulomb dissociation of 8B and the 8B solar neutrino flux

    International Nuclear Information System (INIS)

    Gai, M.

    1994-01-01

    The Coulomb Dissociation of 8 B was measured using 46.5 MeV/u 8 B radioactive beams from the RIKEN-RIPS Radioactive Beam Facility, in an attempt to measure the 7 Be(p,γ) 8 B reaction at low energy, of relevance to estimating the 8 B solar neutrino flux. The experimental setup is discussed and the results are consistent with the lower value of S 17 measured by Filippone et al and Vaughn et al

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

    International Nuclear Information System (INIS)

    Bernabei, R.; D'Angelo, S.; Di Marco, A.; Belli, P.; Cappella, F.; Caracciolo, V.; Cerulli, R.; Dai, C.J.; He, H.L.; Kuang, H.H.; Ma, X.H.; Sheng, X.D.; Wang, R.G.; D'Angelo, A.; Incicchitti, A.; Montecchia, F.; Ye, Z.P.

    2014-01-01

    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.)

  14. Observation of Muon Neutrino Charged Current Events in an Off-Axis Horn-Focused Neutrino Beam Using the NOvA Prototype Detector

    Energy Technology Data Exchange (ETDEWEB)

    Diaz, Enrique Arrieta [Michigan State Univ., East Lansing, MI (United States)

    2014-01-01

    The NOνA is a long base-line neutrino oscillation experiment. It will study the oscillations between muon and electron neutrinos through the Earth. NOνA consists of two detectors separated by 810 km. Each detector will measure the electron neutrino content of the neutrino (NuMI) beam. Differences between the measurements will reveal details about the oscillation channel. The NOνA collaboration built a prototype detector on the surface at Fermilab in order to develop calibration, simulation, and reconstruction tools, using real data. This 220 ton detector is 110 mrad off the NuMI beam axis. This off-axis location allows the observation of neutrino interactions with energies around 2 GeV, where neutrinos come predominantly from charged kaon decays. During the period between October 2011 and April 2012, the prototype detector collected neutrino data from 1.67 × 1020 protons on target delivered by the NuMI beam. This analysis selected a number of candidate charged current muon neutrino events from the prototype data, which is 30% lower than predicted by the NOνA Monte Carlo simulation. The analysis suggests that the discrepancy comes from an over estimation of the neutrino flux in the Monte Carlo simulation, and in particular, from neutrinos generated in charged kaon decays. The ratio of measured divided by the simulated flux of muon neutrinos coming from charged kaon decays is: 0.70+0.108 -0.094. The NOνA collaboration may use the findings of this analysis to introduce a more accurate prediction of the neutrino flux produced by the NuMI beam in future Monte Carlo simulations.

  15. Evidence for massive neutrinos from cosmic microwave background and lensing observations.

    Science.gov (United States)

    Battye, Richard A; Moss, Adam

    2014-02-07

    We discuss whether massive neutrinos (either active or sterile) can reconcile some of the tensions within cosmological data that have been brought into focus by the recently released Planck data. We point out that a discrepancy is present when comparing the primary CMB and lensing measurements both from the CMB and galaxy lensing data using CFHTLenS, similar to that which arises when comparing CMB measurements and SZ cluster counts. A consistent picture emerges and including a prior for the cluster constraints and BAOs we find that for an active neutrino model with three degenerate neutrinos, ∑m(ν)=(0.320±0.081)  eV, whereas for a sterile neutrino, in addition to 3 neutrinos with a standard hierarchy and ∑m(ν)=0.06  eV, m(ν,sterile)(eff)=(0.450±0.124)  eV and ΔN(eff)=0.45±0.23. In both cases there is a significant detection of modification to the neutrino sector from the standard model and in the case of the sterile neutrino it is possible to reconcile the BAO and local H0 measurements. However, a caveat to our result is some internal tension between the CMB and lensing and cluster observations, and the masses are in excess of those estimated from the shape of the matter power spectrum from galaxy surveys.

  16. Probing nonstandard decoherence effects with solar and KamLAND neutrinos

    International Nuclear Information System (INIS)

    Fogli, G. L.; Lisi, E.; Marrone, A.; Montanino, D.; Palazzo, A.

    2007-01-01

    It has been speculated that quantum-gravity might induce a foamy space-time structure at small scales, randomly perturbing the propagation phases of free-streaming particles (such as kaons, neutrons, or neutrinos). Particle interferometry might then reveal nonstandard decoherence effects, in addition to standard ones (due to, e.g., finite source size and detector resolution.) In this work we discuss the phenomenology of such nonstandard effects in the propagation of electron neutrinos in the Sun and in the long-baseline reactor experiment KamLAND, which jointly provide us with the best available probes of decoherence at neutrino energies E∼few MeV. In the solar neutrino case, by means of a perturbative approach, decoherence is shown to modify the standard (adiabatic) propagation in matter through a calculable damping factor. By assuming a power-law dependence of decoherence effects in the energy domain (E n with n=0, ±1, ±2), theoretical predictions for two-family neutrino mixing are compared with the data and discussed. We find that neither solar nor KamLAND data show evidence in favor of nonstandard decoherence effects, whose characteristic parameter γ 0 can thus be significantly constrained. In the ''Lorentz-invariant'' case n=-1, we obtain the upper limit γ 0 -26 GeV at 95% C.L. In the specific case n=-2, the constraints can also be interpreted as bounds on possible matter density fluctuations in the Sun, which we improve by a factor of ∼2 with respect to previous analyses

  17. 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...

  18. New enhancement mechanism of the transitions in the Earth of the solar and atmospheric neutrinos crossing the Earth core

    International Nuclear Information System (INIS)

    Petcov, S.T.

    1999-01-01

    It is shown that the ν 2 → ν e and ν μ → ν e (ν e → ν μ(τ) ) transitions respectively of the solar and atmospheric neutrinos in the Earth in the case of ν e - ν μ(τ) mixing in vacuum, are strongly enhanced by a new type of resonance when the neutrinos cross the Earth core. The resonance is operative at small mixing angles but differs from the MSW one. It is in many respects similar to the electron paramagnetic resonance taking place in a specific configuration of two magnetic fields. The conditions for existence of the new resonance include, in particular, specific constraints on the neutrino oscillation lengths in the Earth mantle and in the Earth core, thus the resonance is a 'neutrino oscillation length resonance'. It leads also to enhancement of the ν 2 → ν e and ν e → ν s transitions in the case of ν e - ν s mixing and of the ν-bar s (or ν μ → ν s ) transitions at small mixing angles. The presence of the neutrino oscillation length resonance in the transitions of solar and atmospheric neutrinos traversing the Earth core has important implications for current and future solar and atmospheric neutrino experiments, and more specifically, for the interpretation of the results of the Super-Kamiokande experiment

  19. The Case of Missing Solar Neutrinos with their Split Personalities

    Indian Academy of Sciences (India)

    iment is exclusively sensitive because of the extremely high-temperature ... fairly general arguments independent of any underly- ing solar models which can ... is lower than the SNO /. Superkamiokande event rate recording all the three flav-.

  20. Detector development and background estimation for the observation of Coherent Neutrino Nucleus Scattering (CNNS)

    Energy Technology Data Exchange (ETDEWEB)

    Guetlein, Achim; Ciemniak, Christian; Feilitzsch, Franz von; Lanfranchi, Jean-Come; Oberauer, Lothar; Potzel, Walter; Roth, Sabine; Schoenert, Stefan; Sivers, Moritz von; Strauss, Raimund; Wawoczny, Stefan; Willers, Michael; Zoeller, Andreas [Technische Universitaet Muenchen, Physik-Department, E15 (Germany)

    2012-07-01

    The Coherent Neutrino Nucleus Scattering (CNNS) is a neutral current process of the weak interaction and is thus flavor independent. A low-energetic neutrino scatters off a target nucleus. For low transferred momenta the wavelength of the transferred Z{sup 0} boson is comparable to the diameter of the target nucleus. Thus, the neutrino interacts with all nucleons coherently and the cross section for the CNNS is enhanced. To observe CNNS for the first time we are developing cryogenic detectors with a target mass of about 10 g each and an energy threshold of less than 0.5 keV. The current status of this development is presented as well as the estimated background for an experiment in the vicinity of a nuclear power reactor as a strong neutrino source.

  1. Eclipsed neutrinos

    International Nuclear Information System (INIS)

    Anon.

    1995-01-01

    Full text: The total solar eclipse visible in Southern Asia on 24 October provided an opportunity for an unusual physics experiment. At face value, the levels of solar neutrinos detected on the Earth's surface are difficult to understand and suggest that perhaps the composition of solar neutrinos oscillates between different neutrino types on their journey. In this way neutrinos originating in the Sun as electrontype could convert into heavy neutrinos, which could subsequently disintegrate into an electron-neutrino and a photon. In certain neutrino scenarios, such a photon would have an energy corresponding to that of visible light, and in principle should be detectable if there are enough of them. The problem is that they would normally be swamped by the copious photons of sunlight. The 24 October solar eclipse provided a chance to check this out. A team led by François Vannucci, spokesman of the Nomad neutrino experiment at CERN, en route to the 'Rencontres du Vietnam' physics meeting in Ho Chi Minh Ville, set up a CCD-equipped telescope. To insure against cloud cover, a second telescope followed the eclipse in the desert of Rajastan, India, where the eclipse was to last only half as long, but the chance of cloud was minimal. No background solar signal was seen, or, expressed in physics terms, if solar radiation has any heavy neutrino component, then less than a millionth of it disintegrates into an electron neutrino and a visible photon before it arrives at the Earth. The negative result also has implications for candidate massive, unstable neutrinos from other sources, notably a component of the missing 'dark matter' of the Universe. The next such eclipse should be visible in North Asia in 1997, when hopefully better measurements will be made

  2. Neutrino transition magnetic moments and the solar magnetic field on the light of the Kamland evidence

    CERN Document Server

    Antonelli, V; Picariello, M; Pulido, J; Torrente-Lujan, E

    2003-01-01

    We present here a recopilation of recent results about the possibility of detecting solar electron antineutrinos produced by solar core and convective magnetic fields. These antineutrinos are predicted by spin-flavor oscillations at a significant rate even if this mechanism is not the leading solution to the SNP. Using the recent Kamland results and assuming a concrete model for antineutrino production by spin-flavor precession in the convective zone based on chaotic magnetic fields,we obtain bounds on the flux of solar antineutrinos, on the average conversion neutrino-antineutrino probability and on intrinsic neutrino magnetic moment. In the most conservative case, $\\mu\\lsim 2.5\\times 10^{-11} \\mu_B$ (95% CL). When studying the effects of a core magnetic field, we find in the weak limit a scaling of the antineutrino probability with respect to the magnetic field profile in the sense that the same probability function can be reproduced by any profile with a suitable peak field value. In this way the solar ele...

  3. The oscillation probability of GeV solar neutrinos of all active species

    International Nuclear Information System (INIS)

    Gouvea, Andre de

    2001-01-01

    I discuss the oscillation probability of O(GeV) neutrinos of all active flavours produced inside the Sun and detected at the Earth. In the GeV energy regime, matter effects are potentially important both for the ''1-3'' system and the ''1-2'' system. A numerical scan of the multidimensional three-flavour parameter space is presented. One curiosity is that in the three-flavour oscillation case P αβ ≠ P βα for a large portion of the parameter space, even if the MNS matrix is real. Oscillation effects computed here may play a large role in interpreting solar WIMP search data from large neutrino telescopes

  4. Hint of nonstandard Mikheyev-Smirnov-Wolfenstein dynamics in solar neutrino conversion

    International Nuclear Information System (INIS)

    Palazzo, Antonio

    2011-01-01

    Motivated by the recent low-threshold measurements of the solar 8 B neutrino spectrum performed by Borexino, Super-Kamiokande and the Sudbury Neutrino Observatory--all now monitoring the transition regime between low-energy (vacuumlike) and high-energy (matter-dominated) flavor conversions--we consider the role of subdominant dynamical terms induced by new flavor-changing interactions. We find that the presence of such perturbations with strength ∼10 -1 G F is now favored, offering a better description of the anomalous behavior suggested by the new results, whose spectrum shows no sign of the typical low-energy upturn predicted by the standard Mikheyev-Smirnov-Wolfenstein (MSW) mechanism. Our findings, if interpreted in a 2-flavor scheme, provide a hint of such new interactions at the ∼2σ level, which is rather robust with respect to 3-flavor effects possibly induced by nonzero θ 13 .

  5. Hint of nonstandard Mikheyev-Smirnov-Wolfenstein dynamics in solar neutrino conversion

    Science.gov (United States)

    Palazzo, Antonio

    2011-05-01

    Motivated by the recent low-threshold measurements of the solar B8 neutrino spectrum performed by Borexino, Super-Kamiokande and the Sudbury Neutrino Observatory—all now monitoring the transition regime between low-energy (vacuumlike) and high-energy (matter-dominated) flavor conversions—we consider the role of subdominant dynamical terms induced by new flavor-changing interactions. We find that the presence of such perturbations with strength ˜10-1GF is now favored, offering a better description of the anomalous behavior suggested by the new results, whose spectrum shows no sign of the typical low-energy upturn predicted by the standard Mikheyev-Smirnov-Wolfenstein (MSW) mechanism. Our findings, if interpreted in a 2-flavor scheme, provide a hint of such new interactions at the ˜2σ level, which is rather robust with respect to 3-flavor effects possibly induced by nonzero θ13.

  6. Dark matter and the solar neutrino problem: Can particle physics provide a single solution

    International Nuclear Information System (INIS)

    West, G.B.

    1989-01-01

    We show how a relatively simple extension of the standard model can give a ''natural'' explanation for both the solar neutrino and dark matter problems. What is required is a new stable neutral lepton with a mass in the 4--8 GeV range. One possibility is a fourth generation neutrino interacting with matter either electromagnetically or via higgs-exchange (in addition, of course, to Z degree-exchange). In the former case, a new charged lepton with mass ∼10GeV would be required in order to generate a sufficiently large magnetic moment. The present experimental situation makes this possibility rather doubtful. In the latter case, a light higgs with mass ∼1GeV is required; this is still not ruled out experimentally. In any case, direct (or indirect) detection of dark matter will, during the next year, seal the fate of this model. 29 refs

  7. Research ampersand development of a helium-4 based solar neutrino detector

    International Nuclear Information System (INIS)

    Lanou, R.E.; Maris, H.J.; Seidel, G.M.

    1989-12-01

    This Progress Report covers the first six months of our May 1989 Continuation Grant. The purpose of the project is to develop and test a new detection technique for neutrinos using 4 He in the superfluid state. Based upon the expected test results it should be possible to design a practical detector leading to the ultimate goal of detecting low energy solar neutrinos. During the last six months the construction phase has moved ahead substantially. Among the areas of progress discussed in the report are: the construction of the cryostat and dilution refrigerators; the gas handling systems; computer system design; tests for radioactivity of construction materials and roton pulse simulation by computer. 5 figs

  8. E6 based mechanism for the generation of fermion electric dipole moments: An application to the solar neutrino puzzle

    International Nuclear Information System (INIS)

    Grifols, J.A.

    1987-01-01

    We discuss the electric dipole moments (EDM) of fermions generated by CP-violating phases associated to the new Yukawa couplings involving heavy matter E 6 fields predicted in the framework of superstring theories. While for neutron and electron it is not strictly necessary to resort to a superstring scenario to get a substantial EDM, in the neutrino case a sizeable EDM is a distinctive feature of the superstring. We thus focus on the neutrino EDM and discuss its relevance for the solution of the solar neutrino problem. (orig.)

  9. Neutrino mass spectrum with υμ → υs oscillations of atmospheric neutrinos

    International Nuclear Information System (INIS)

    Liu, Q.Y.; Smirnov, A.Yu.

    1998-02-01

    We consider the ''standard'' spectrum of the active neutrinos (characterized by strong mass hierarchy and small mixing) with additional sterile, υ s . The sterile neutrino mixes strongly with the muon neutrino, so that υ μ ↔ υ s oscillations solve the atmospheric neutrino problem. We show that the parametric enhancement of the υ μ ↔ υ s oscillations occurs for the high energy atmospheric neutrinos which cross the core of the Earth. This can be relevant for the anomaly observed by the MACRO experiment. Solar neutrinos are converted both to υ μ and υ s . The heaviest neutrino (approx. υ τ ) may compose the hot dark matter of the Universe. Phenomenology of this scenario is elaborated and crucial experimental signatures are identified. We also discuss properties of the underlying neutrino mass matrix. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-09-14

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

  11. 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.

  12. FIRST STUDY OF DARK MATTER PROPERTIES WITH DETECTED SOLAR GRAVITY MODES AND NEUTRINOS

    Energy Technology Data Exchange (ETDEWEB)

    Turck-Chieze, S.; Garcia, R. A. [CEA/DSM/IRFU/SAp-AIM, CE Saclay, Orme des Merisiers, 91191 Gif-sur-Yvette (France); Lopes, I. [Centro Multidisciplinar de Astrofisica, Instituto Superior Tecnico, Av. Rovisco Pais, 1049-001 Lisboa (Portugal); Ballot, J. [Institut de Recherche en Astrophysique et Planetologie, CNRS, 14 avenue Edouard Belin and Universite de Toulouse, UPS-OMP, IRAP, 31400 Toulouse (France); Couvidat, S. [W.W. Hansen. E. P. L., Stanford University, Stanford, CA 94305 (United States); Mathur, S. [High Altitude Observatory, NCAR, P.O. Box 3000, Boulder, CO 80307 (United States); Salabert, D. [CNRS, Observatoire de la Cote d' Azur, Universite de Nice Sophia-Antipolis, BP 4229, 06304 Nice Cedex 4 (France); Silk, J., E-mail: Sylvaine.Turck-Chieze@cea.fr [UPMC-CNRS, UMR7095, Institut d' Astrophysique de Paris, F-75014 Paris (France)

    2012-02-10

    We derive new limits on the cold dark matter properties for weakly interacting massive particles (WIMPs), potentially trapped in the solar core by using for the first time the central temperature constrained by boron neutrinos and the central density constrained by the dipolar gravity modes detected with the Global Oscillations at Low Frequency/Solar Helioseismic Observatory instrument. These detections disfavor the presence of non-annihilating WIMPs for masses {<=}10 GeV and spin dependent cross-sections >5 Multiplication-Sign 10{sup -36} cm{sup 2} in the solar core but cannot constrain WIMP annihilation models. We suggest that in the coming years helio- and asteroseismology will provide complementary probes of dark matter.

  13. Observing a light dark matter beam with neutrino experiments

    Science.gov (United States)

    Deniverville, Patrick; Pospelov, Maxim; Ritz, Adam

    2011-10-01

    We consider the sensitivity of fixed-target neutrino experiments at the luminosity frontier to light stable states, such as those present in models of MeV-scale dark matter. To ensure the correct thermal relic abundance, such states must annihilate via light mediators, which in turn provide an access portal for direct production in colliders or fixed targets. Indeed, this framework endows the neutrino beams produced at fixed-target facilities with a companion “dark matter beam,” which may be detected via an excess of elastic scattering events off electrons or nuclei in the (near-)detector. We study the high-luminosity proton fixed-target experiments at LSND and MiniBooNE, and determine that the ensuing sensitivity to light dark matter generally surpasses that of other direct probes. For scenarios with a kinetically-mixed U(1)' vector mediator of mass mV, we find that a large volume of parameter space is excluded for mDM˜1-5MeV, covering vector masses 2mDM≲mV≲mη and a range of kinetic mixing parameters reaching as low as κ˜10-5. The corresponding MeV-scale dark matter scenarios motivated by an explanation of the galactic 511 keV line are thus strongly constrained.

  14. Neutrino masses and mixing: evidence and implications

    International Nuclear Information System (INIS)

    Gonzalez-Garcia, M.C.; Nir, Yosef

    2003-01-01

    Measurements of various features of the fluxes of atmospheric and solar neutrinos have provided evidence for neutrino oscillations and therefore for neutrino masses and mixing. The authors review the phenomenology of neutrino oscillations in vacuum and in matter. They present the existing evidence from solar and atmospheric neutrinos as well as the results from laboratory searches, including the final status of the Liquid Scintillator Neutrino Detector (LSND) experiment. The theoretical inputs that are used to interpret the experimental results are described in terms of neutrino oscillations. The allowed ranges for the mass and mixing parameters are derived in two frameworks: First, each set of observations is analyzed separately in a two-neutrino framework; Second, the data from solar and atmospheric neutrinos are analyzed in a three-active-neutrino framework. The theoretical implications of these results are then discussed, including the existence of new physics, the estimate of the scale of this new physics, and the lessons for grand unified theories, for models of extra dimensions and singlet fermions in the bulk, and for flavor models

  15. A Lithium-Beryllium Method for the Detection of Solar Neutrinos

    OpenAIRE

    Kopylov, A. V.; Orekhov, I. V.; Petukhov, V. V.; Solomatin, A. E.

    2009-01-01

    A method for the detection of solar neutrino has been developed using the laboratory bench installations. The efficiency of the extraction of beryllium from lithium as high as 96.4{%} has been achieved, and it was shown that lithium losses during the extraction were less than 1{%}. The prospects of a full-scale experiment with a 10-t lithium detector consisting of twenty 500-kg lithium modules are discussed. The technical solutions formulated on the basis of this study enable to make design o...

  16. Earth effect in the MSW analysis of the solar neutrino experiments

    International Nuclear Information System (INIS)

    Hata, N.; Langacker, P.

    1993-01-01

    We consider the Earth effect in the combined Mikheyev-Smirnov-Wolfenstein analysis of the solar neutrino experiments including theoretical uncertainties. Using the time-averaged data, the allowed large-angle region extends to much smaller angles than when the Earth effect is ignored. However, the additional constraint from the Kamiokande II day-night data excludes the parameter space most sensitive to the Earth effect, leaving only a small large-angle region close to maximal mixing at 90% C.L. The nonadiabatic solution remains unaffected by the Earth effect and is still preferred

  17. Direct detection of light dark matter and solar neutrinos via color center production in crystals

    OpenAIRE

    Budnik, Ranny; Cheshnovsky, Ori; Slone, Oren; Volansky, Tomer

    2018-01-01

    We propose a new low-threshold direct-detection concept for dark matter and for coherent nuclear scattering of solar neutrinos, based on the dissociation of atoms and subsequent creation of color center type defects within a lattice. The novelty in our approach lies in its ability to detect single defects in a macroscopic bulk of material. This class of experiments features ultra-low energy thresholds which allows for the probing of dark matter as light as O(10) MeV through nuclear scattering...

  18. Search for neutrinos from TANAMI observed AGN using Fermi lightcurves wit ANTARES

    International Nuclear Information System (INIS)

    Fehn, Kerstin

    2015-01-01

    Active galactic nuclei (AGN) are promising candidates for hadronic acceleration. The combination of radio, gamma ray and neutrino data should give information on their properties, especially concerning the sources of the high-energetic cosmic rays. Assuming a temporal correlation of gamma and neutrino emission in AGN the background of neutrino telescopes can be reduced using gamma ray lightcurves. Thereby the sensitivity for discovering cosmic neutrino sources is enhanced. In the present work a stacked search for a group of AGN with the ANTARES neutrino telescope in the Mediterranean is presented. The selection of AGN is based on the source sample of TANAMI, a multiwavelength observation program (radio to gamma rays) of extragalactic jets southerly of -30 declination. In the analysis lightcurves of the gamma satellite Fermi are used. In an unbinned maximum likelihood approach the test statistic in the background only case and in the signal and background case is determined. For the investigated 10% of data of ANTARES within the measurement time between 01.09.2008 and 30.07.2012 no significant excess is observed. So on the total flux of the AGN of the stacked search an upper limit can be set.

  19. Effects of fermionic singlet neutrinos on high- and low-energy observables

    International Nuclear Information System (INIS)

    Weiland, C.

    2013-01-01

    In this doctoral thesis, we study both low- and high-energy observables related to massive neutrinos. Neutrino oscillations have provided indisputable evidence in favour of non-zero neutrino masses and mixings. However, the original formulation of the standard model cannot account for these observations, which calls for the introduction of new physics. Among many possibilities, we focus here on the inverse seesaw, a neutrino mass generation mechanism in which the standard model is extended with fermionic gauge singlets. This model offers an attractive alternative to the usual seesaw realisations since it can potentially have natural Yukawa couplings (O(1)) while keeping the new physics scale at energies within the reach of the LHC. Among the many possible effects, this scenario can lead to deviations from lepton flavour universality. We have investigated these signatures and found that the ratios R K and R π provide new, additional constraints on the inverse seesaw. We have also considered the embedding of the inverse seesaw in supersymmetric models. This leads to increased rates for various lepton flavour violating processes, due to enhanced contributions from penguin diagrams mediated by the Higgs and Z 0 bosons. Finally, we also found that the new invisible decay channels associated with the sterile neutrinos present in the super-symmetric inverse seesaw could significantly weaken the constraints on the mass and couplings of a light CP-odd Higgs boson. (author)

  20. arXiv Scanning the Earth with solar neutrinos and DUNE

    CERN Document Server

    Ioannisian, Ara; Wyler, Daniel

    2017-08-08

    We explore oscillations of the solar B8 neutrinos in the Earth in detail. The relative excess of night νe events (the day-night asymmetry) is computed as function of the neutrino energy and the nadir angle η of its trajectory. The finite energy resolution of the detector causes an important attenuation effect, while the layer-like structure of the Earth density leads to an interesting parametric suppression of the oscillations. Different features of the η- dependence encode information about the structure (such as density jumps) of the Earth density profile; thus measuring the η distribution allows the scanning of the interior of the Earth. We estimate the sensitivity of the DUNE experiment to such measurements. About 75 neutrino events are expected per day in 40 kt. For high values of Δm212 and Eν>11  MeV, the corresponding D-N asymmetry is about 4% and can be measured with 15% accuracy after 5 years of data taking. The difference of the D-N asymmetry between high and low values of Δm212 can be ...

  1. Observable lepton number violation with predominantly Dirac nature of active neutrinos

    Energy Technology Data Exchange (ETDEWEB)

    Borah, Debasish [Department of Physics, Indian Institute of Technology Guwahati,Assam-781039 (India); Dasgupta, Arnab [Institute of Physics, HBNI,Sachivalaya Marg, Bhubaneshwar-751005 (India)

    2017-01-17

    We study a specific version of SU(2){sub R}×SU(2){sub L}×U(1){sub B−L} models extended by discrete symmetries where the new physics sector responsible for tiny neutrino masses at leading order remains decoupled from the new physics sector that can give rise to observable signatures of lepton number violation such as neutrinoless double beta decay. More specifically, the dominant contribution to light neutrino masses comes from a one-loop Dirac mass. At higher loop level, a tiny Majorana mass also appears which remains suppressed by many order of magnitudes in comparison to the Dirac mass. Such a model where the active neutrinos are predominantly of Dirac type, also predicts observable charged lepton flavour violation like μ→3e,μ→eγ and multi-component dark matter.

  2. Underground neutrino astronomy

    International Nuclear Information System (INIS)

    Schramm, D.N.

    1983-02-01

    A review is made of possible astronomical neutrino sources detectable with underground facilities. Comments are made about solar neutrinos and gravitational-collapse neutrinos, and particular emphasis is placed on ultra-high-energy astronomical neutrino sources. An appendix mentions the exotic possibility of monopolonium

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

    Science.gov (United States)

    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 Δm2-tan2θ plane. The best-fit from a combined analysis which uses the KamLAND rate plus global solar data comes at Δm2=6.06×10-5 eV2 and tan2θ=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 Δm2=7.17×10-5 eV2 and tan2θ=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 /3σ. The low Δm2 solution (LOW) is now ruled out at about 5/σ with respect to the LMA solution.

  4. 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.

  5. Observation of Electron Neutrino Appearance in the NuMI Beam with the NOvA Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Niner, Evan David [Indiana Univ., Bloomington, IN (United States)

    2015-01-01

    NOvA is a long-baseline neutrino oscillation experiment that uses two functionally identical detectors separated by 810 kilometers at locations 14 milliradians off-axis from the NuMI muon neutrino beam at Fermilab. At these locations the beam energy peaks at 2 GeV. This baseline is the longest in the world for an accelerator-based neutrino oscillation experiment, which enhances the sensitivity to the neutrino mass ordering. The experiment studies oscillations of the muon neutrino and anti-neutrino beam that is produced. Both detectors completed commissioning in the summer of 2014 and continue to collect data. One of the primary physics goals of the experiment is the measurement of electron neutrino appearance in the muon neutrino beam which yields measurements of the oscillation parameters sin213, δ , and the neutrino mass ordering within the standard model of neutrino oscillations. This thesis presents the analysis of data collected between February 2014 and May 2015, corresponding to 3.52 X 1020 protons-on-target. In this first analysis NOvA recorded 6 electron neutrino candidates, which is a 3.3σ observation of electron neutrino appearance. The T2K experiment performs the same measurement on a baseline of 295 kilometers and has a 1 σ preference for the normal mass ordering over the inverted ordering over the phase space of the CP violating parameter δ, which is also weakly seen in the NOvA result. By the summer of 2016 NOvA will triple its statistics due to increased beam power and a completed detector. If electron neutrinos continue to be observed at the current rate NOvA will be able to establish a mass ordering preference at a similar confidence level to T2K.

  6. Detection of a Type IIn Supernova in Optical Follow-up Observations of IceCube Neutrino Events

    OpenAIRE

    Aartsen, M. G.; Abraham, K.; Ackermann, M.; Adams, J.; Aguilar, J. A.; Ahlers, M.; Ahrens, M.; Altmann, D.; Anderson, T.; Archinger, M.; Arguelles, C.; Arlen, T. C.; Auffenberg, J.; Bai, X.; Barwick, S. W.

    2015-01-01

    The IceCube neutrino observatory pursues a follow-up program selecting interesting neutrino events in real-time and issuing alerts for electromagnetic follow-up observations. In 2012 March, the most significant neutrino alert during the first three years of operation was issued by IceCube. In the follow-up observations performed by the Palomar Transient Factory (PTF), a Type IIn supernova (SN IIn) PTF12csy was found 0.degrees 2 away from the neutrino alert direction, with an error radius of 0...

  7. Precision measurement of the 7Be solar neutrino rate and absence of day-night asymmetry in Borexino

    International Nuclear Information System (INIS)

    Davini, S.

    2011-01-01

    Borexino, in data taking since May 2007, is the only experiment capable to perform the measurement of low-energy solar-ν. Borexino has performed the first direct measurement of the 7 Be solar-ν rate with accuracy better than 5%. The absence of day-night asymmetry of the 7 Be solar-ν rate was measured with a total uncertainty of 1%. Borexino results alone reject the Low Δm 2 (LOW) region of solar-ν oscillation parameters at more than 8.5 σ CL. Combined with the other solar-ν data, Borexino measurements isolate the Large Mixing Angle (LMA)- Mikheyev Smirnov Wolfenstein (MSW) solution of neutrino oscillations without assuming CPT invariance in the neutrino sector.

  8. A comment on the 7Be(p,γ)8B cross section and the solar neutrino problem

    International Nuclear Information System (INIS)

    Barker, F.C.; Spear, R.H.

    1986-02-01

    Evidence is presented which indicates that the accepted value for the cross section of the 7 Be(p,γ) 8 B reaction at stellar energies is probably too large. It is suggested that the accepted value of the 7 Li(d,p) 8 Li cross section, which has been used for normalization purposes, is too large; that the accepted value for the ratio of the 7 Be(p,γ) 8 B and 7 Li(d,p) 8 Li cross sections is too large; and that the energy dependence used to extrapolate to stellar energies from the higher energies at which measurements have been made is inaccurate. The consequent reduction of the 7 Be(p,γ) 8 B cross section by about 30% would not be sufficient to resolve the solar neutrino problem but would significantly lessen the discrepancy between observation and calculation

  9. 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)

  10. Supernova neutrinos and explosive nucleosynthesis

    Science.gov (United States)

    Kajino, T.; Aoki, W.; Cheoun, M.-K.; Hayakawa, T.; Hidaka, J.; Hirai, Y.; Mathews, G. J.; Nakamura, K.; Shibagaki, S.; Suzuki, T.

    2014-05-01

    Core-collapse supernovae eject huge amount of flux of energetic neutrinos. We studied the explosive nucleosyn-thesis in supernovae and found that several isotopes 7Li, 11B, 92Nb, 138La and 180Ta 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 θ13, simultaneously. There is recent evidence that SiC X grains from the Murchison meteorite may contain supernova-produced light elements 11B and 7Li encapsulated in the presolar grains. Combining the recent experimental constraints on θ13, 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.

  11. 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.

  12. Frontiers in neutrino physics - Transparencies

    International Nuclear Information System (INIS)

    Akhmedov, E.; Balantekin, B.; Conrad, J.; Engel, J.; Fogli, G.; Giunti, C.; Espinoza, C.; Lasserre, T.; Lazauskas, R.; Lhuiller, D.; Lindner, M.; Martinez-Pinedo, G.; Martini, M.; McLaughlin, G.; Mirizzi, A.; Pehlivan, Y.; Petcov, S.; Qian, Y.; Serenelli, A.; Stancu, I.; Surman, R.; Vaananen, D.; Vissani, F.; Vogel, P.

    2012-01-01

    This document gathers the slides of the presentations. The purpose of the conference was to discuss the last advances in neutrino physics. The presentations dealt with: -) the measurement of the neutrino velocity, -) neutrino oscillations, -) anomaly in solar models and neutrinos, -) double beta decay, -) self refraction of neutrinos, -) cosmic neutrinos, -) antineutrino spectra from reactors, and -) some aspects of neutrino physics with radioactive ion beams. (A.C.)

  13. Sterile neutrino

    International Nuclear Information System (INIS)

    Anon.

    2007-01-01

    Paper deals with the information on the occurrence of the fields of the sterile neutrinos (the righthanded ones) mixed with the normal neutrinos (the lefthanded ones). Both the Max Plank Radioastronomy Institute and the Los Angeles University assumes that the occurrence of the keV mass sterile neutrinos may explain the dark matter nature, the fast rotation of the observed pulsars and the reionization processes. The issues associated with the possibility to record the sterile neutrinos were analyzed in the course of the Sterile Neutrinos in Astrophysics and Cosmology Workshop (Crans Montana, March 2006 [ru

  14. Describing the observed cosmic neutrinos by interactions of nuclei with matter

    International Nuclear Information System (INIS)

    Winter, Walter

    2014-07-01

    IceCube have observed neutrinos which are presumably of extra-galactic origin. Since specific sources have not yet been identified, we discuss what could be learned from the conceptual point of view. We use a simple model for neutrino production from the interactions between nuclei and matter, and we focus on the description of the spectral shape and flavor composition observed by IceCube. Our main parameters are spectral index, maximal energy, magnetic field, and composition of the accelerated nuclei. We show that a cutoff at PeV energies can be achieved by soft enough spectra, a cutoff of the primary energy, or strong enough magnetic fields. These options, however, are difficult to reconcile with the hypothesis that these neutrinos originate from the same sources as the ultra-high energy cosmic rays. We demonstrate that heavier nuclei accelerated in the sources may be a possible way out if the maximal energy scales appropriately with the mass number of the nuclei. In this scenario, neutrino observations can actually be used to test the UHECR acceleration mechanism. We also emphasize the need for a volume upgrade of the IceCube detector for future precision physics, for which the flavor information becomes a statistical meaningful model discriminator as qualitatively new ingredient.

  15. Development and validation of HELLAZ1 detector, contribution to the project HELLAZ concerning the detection of solar neutrinos

    International Nuclear Information System (INIS)

    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.)

  16. Search for neutrino events in the Kamiokande-II detector in correlation with the solar-flare activity in March 1989

    International Nuclear Information System (INIS)

    Hirata, K.S.; Kajita, T.; Kifune, T.

    1989-12-01

    A search has been made for neutrino events (E v > or approx. 50 MeV) in the Kamiokande-II water Cherenkov detector in correlation with the great solar-flare activity observed in March 1989. No evidence was obtained for such a correlation. Upper limits are separately given for the optical importance 4, 3, and 2 flares for both time-integrated and time-averaged solar-flare ν e fluxes at E v = 50 MeV and 100 MeV. At E v = 100 MeV, the 90% confidence-level upper limit for the time-integrated ν e flux per importance 4 (3) flare is 3.5 x 10 7 (1.4x10 7 ) cm -2 . Even the upper limit for the importance 4 flare is considerably lower than the ν e flux at the corresponding energy needed to explain the excess neutrino captures reported in some of the 37 Cl experimental runs when large solar flares occurred. A search has also been made for low-energy events (recoil e +- energy > or approx. 10 MeV) in correlation with importance ≥ 2 flares and with the solar proton flux ≥ 10 MeV). Again, no significant signal has been observed. (author)

  17. A review of superheated superconducting granules as a detector for dark matter, solar neutrinos, monopoles and double beta decay

    International Nuclear Information System (INIS)

    Pretzl, K.P.

    1987-11-01

    The use of superheated superconducting granules as a particle detector is reviewed. Their application for the detection of dark matter, solar neutrinos, monopoles, and double beta decay is described. A status report on the experimental development of these devices is given. (orig.)

  18. Solar neutrinos: Global analysis with day and night spectra from SNO

    Science.gov (United States)

    de Holanda, Pedro C.; Smirnov, A. Yu.

    2002-12-01

    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 large-mixing angle (LMA) Mikheyev-Smirnov-Wolfenstein solution with Δm2=6.15×10-5 eV2, tan2θ=0.41, fB=1.05, where fB is the boron neutrino flux in units of the corresponding flux in the standard solar model (SSM). At the 3σ level we find the following upper bounds: tan2θ<0.84 and Δm2<3.6×10-4 eV2. From a 1σ interval we expect the day-night asymmetries of the charged current and electron scattering events to be ACCDN=3.9+3.6-2.9% and AESDN=2.1+2.1-1.4%. The only other solution which appears at the 3σ level is the VAC solution with Δm2=4.5×10-10 eV2, tan2θ=2.1, and fB=0.75. The best fit point in the low probability, low mass region, with Δm2=0.93×10-7 eV2 and tan2θ=0.64, is accepted at 99.95% (3.5σ) C.L. The least χ2 point from the small mixing angle solution region, with Δm2=4.6×10-6 eV2 and tan2θ=5×10-4, could be accepted at the 5.5σ level only. In the three neutrino context the influence of θ13 is studied. We find that with an increase of θ13 the LMA best fit point shifts to a larger Δm2, the mixing angle is practically unchanged, and the quality of the fit becomes worse. The fits of LOW and SMA slightly improve. Predictions for the KamLAND experiment (total rates, spectrum distortion) have been calculated.

  19. Two lectures on neutrinos

    International Nuclear Information System (INIS)

    Ramond, P.

    1992-01-01

    These notes are based on two lectures delivered at the School. A general description of neutrinos is presented, first in purely kinematic terms, then in the context of the Standard Model, focusing on the role of the global lepton numbers. Standard Model extensions with massive neutrinos are cataloged. Several popular mass matrices for neutrinos, and their consequences are presented. They proceed to give an extended discussion of neutrino oscillations in matter, and apply the results to the solar neutrinos

  20. NEUTRINO mass textures and the nature of new physics implied by present neutrino data

    International Nuclear Information System (INIS)

    Mohapatra, R.N.

    1997-01-01

    If all the indications for neutrino oscillations observed in the solar, atmospheric neutrino data as well as in the LSND experiment are borned out by the ongoing and future experiments, then they severely constrain the neutrino mass texture. In particular, the need for an extra ultra-light sterile neutrino species is hard to avoid. Such an extra neutrino has profound implication not only for physics beyond the standard model but even perhaps for physics beyond conventional grand unification. A scenario involving a parallel (or shadow) universe that interacts with the familiar universe only via the gravitational interactions where the ultra-lightness of the sterile neutrino follows from the same physics that explains the near masslessness of the familiar neutrinos is discussed in the presentation

  1. Search for Neutrinos from the Sun

    Science.gov (United States)

    Davis, Raymond Jr.

    1968-09-01

    A solar neutrino detection system has been built to observe the neutrino radiation from the sun. The detector uses 3,900,000 liters of tetrachloroethylene as the neutrino capturing medium. Argon is removed from the liquid by sweeping with helium gas, and counted in a small low level proportional counter. The recovery efficiency of the system was tested with Ar{sup 36} by the isotope dilution method, and also with Ar{sup 37} produced in the liquid by fast neutrons. These tests demonstrate that Ar{sup 37} produced in the liquid by neutrino capture can be removed with a 95 percent efficiency by the procedure used.

  2. Measurement of the neutrino component of an antineutrino beam observed by a nonmagnetized detector

    International Nuclear Information System (INIS)

    Aguilar-Arevalo, A. A.; Anderson, C. E.; Fleming, B. T.; Linden, S. K.; Spitz, J.; Brice, S. J.; Brown, B. C.; Ford, R.; Garcia, F. G.; Kobilarcik, T.; Marsh, W.; Moore, C. D.; Polly, C. C.; Russell, A. D.; Stefanski, R. J.; Zeller, G. P.; Bugel, L.; Conrad, J. M.; Karagiorgi, G.; Nguyen, V.

    2011-01-01

    Two methods are employed to measure the neutrino flux of the antineutrino-mode beam observed by the MiniBooNE detector. The first method compares data to simulated event rates in a high-purity ν μ -induced charged-current single π + (CC1π + ) sample while the second exploits the difference between the angular distributions of muons created in ν μ and ν μ charged-current quasielastic (CCQE) interactions. The results from both analyses indicate the prediction of the neutrino flux component of the predominately antineutrino beam is overestimated--the CC1π + analysis indicates the predicted ν μ flux should be scaled by 0.76±0.11, while the CCQE angular fit yields 0.65±0.23. The energy spectrum of the flux prediction is checked by repeating the analyses in bins of reconstructed neutrino energy, and the results show that the spectral shape is well-modeled. These analyses are a demonstration of techniques for measuring the neutrino contamination of antineutrino beams observed by future nonmagnetized detectors.

  3. Forecasting neutrino masses from combining KATRIN and the CMB observations: Frequentist and Bayesian analyses

    Science.gov (United States)

    Host, Ole; Lahav, Ofer; Abdalla, Filipe B.; Eitel, Klaus

    2007-12-01

    We present a showcase for deriving bounds on the neutrino masses from laboratory experiments and cosmological observations. We compare the frequentist and Bayesian bounds on the effective electron neutrino mass mβ which the KATRIN neutrino mass experiment is expected to obtain, using both an analytical likelihood function and Monte Carlo simulations of KATRIN. Assuming a uniform prior in mβ, we find that a null result yields an upper bound of about 0.17 eV at 90% confidence in the Bayesian analysis, to be compared with the frequentist KATRIN reference value of 0.20 eV. This is a significant difference when judged relative to the systematic and statistical uncertainties of the experiment. On the other hand, an input mβ=0.35eV, which is the KATRIN 5σ detection threshold, would be detected at virtually the same level. Finally, we combine the simulated KATRIN results with cosmological data in the form of present (post-WMAP) and future (simulated Planck) observations. If an input of mβ=0.2eV is assumed in our simulations, KATRIN alone excludes a zero neutrino mass at 2.2σ. Adding Planck data increases the probability of detection to a median 2.7σ. The analysis highlights the importance of combining cosmological and laboratory data on an equal footing.

  4. Forecasting neutrino masses from combining KATRIN and the CMB observations: Frequentist and Bayesian analyses

    International Nuclear Information System (INIS)

    Host, Ole; Lahav, Ofer; Abdalla, Filipe B.; Eitel, Klaus

    2007-01-01

    We present a showcase for deriving bounds on the neutrino masses from laboratory experiments and cosmological observations. We compare the frequentist and Bayesian bounds on the effective electron neutrino mass m β which the KATRIN neutrino mass experiment is expected to obtain, using both an analytical likelihood function and Monte Carlo simulations of KATRIN. Assuming a uniform prior in m β , we find that a null result yields an upper bound of about 0.17 eV at 90% confidence in the Bayesian analysis, to be compared with the frequentist KATRIN reference value of 0.20 eV. This is a significant difference when judged relative to the systematic and statistical uncertainties of the experiment. On the other hand, an input m β =0.35 eV, which is the KATRIN 5σ detection threshold, would be detected at virtually the same level. Finally, we combine the simulated KATRIN results with cosmological data in the form of present (post-WMAP) and future (simulated Planck) observations. If an input of m β =0.2 eV is assumed in our simulations, KATRIN alone excludes a zero neutrino mass at 2.2σ. Adding Planck data increases the probability of detection to a median 2.7σ. The analysis highlights the importance of combining cosmological and laboratory data on an equal footing

  5. Search for neutrinos from transient sources with the ANTARES telescope and optical follow-up observations

    International Nuclear Information System (INIS)

    Ageron, Michel; Al Samarai, Imen; Akerlof, Carl; Basa, Stéphane; Bertin, Vincent; Boer, Michel; Brunner, Juergen; Busto, Jose; Dornic, Damien; Klotz, Alain; Schussler, Fabian; Vallage, Bertrand; Vecchi, Manuela; Zheng, Weikang

    2012-01-01

    The ANTARES telescope is well suited to detect neutrinos produced in astrophysical transient sources as it can observe a full hemisphere of the sky at all the times with a duty cycle close to unity and an angular resolution better than 0.5°. Potential sources include gamma-ray bursts (GRBs), core collapse supernovae (SNe), and flaring active galactic nuclei (AGNs). To enhance the sensitivity of ANTARES to such sources, a new detection method based on coincident observations of neutrinos and optical signals has been developed. A fast online muon track reconstruction is used to trigger a network of small automatic optical telescopes. Such alerts are generated one or two times per month for special events such as two or more neutrinos coincident in time and direction or single neutrinos of very high energy. Since February 2009, ANTARES has sent 37 alert triggers to the TAROT and ROTSE telescope networks, 27 of them have been followed. First results on the optical images analysis to search for GRBs are presented.

  6. Search for neutrinos from transient sources with the ANTARES telescope and optical follow-up observations

    Science.gov (United States)

    Ageron, Michel; Al Samarai, Imen; Akerlof, Carl; Basa, Stéphane; Bertin, Vincent; Boer, Michel; Brunner, Juergen; Busto, Jose; Dornic, Damien; Klotz, Alain; Schussler, Fabian; Vallage, Bertrand; Vecchi, Manuela; Zheng, Weikang

    2012-11-01

    The ANTARES telescope is well suited to detect neutrinos produced in astrophysical transient sources as it can observe a full hemisphere of the sky at all the times with a duty cycle close to unity and an angular resolution better than 0.5°. Potential sources include gamma-ray bursts (GRBs), core collapse supernovae (SNe), and flaring active galactic nuclei (AGNs). To enhance the sensitivity of ANTARES to such sources, a new detection method based on coincident observations of neutrinos and optical signals has been developed. A fast online muon track reconstruction is used to trigger a network of small automatic optical telescopes. Such alerts are generated one or two times per month for special events such as two or more neutrinos coincident in time and direction or single neutrinos of very high energy. Since February 2009, ANTARES has sent 37 alert triggers to the TAROT and ROTSE telescope networks, 27 of them have been followed. First results on the optical images analysis to search for GRBs are presented.

  7. Search for neutrinos from transient sources with the ANTARES telescope and optical follow-up observations

    Energy Technology Data Exchange (ETDEWEB)

    Ageron, Michel [CPPM, CNRS/IN2P3 - Universite de Mediterranee, 163 avenue de Luminy, 13288 Marseille Cedex 09 (France); Al Samarai, Imen, E-mail: samarai@cppm.in2p3.fr [CPPM, CNRS/IN2P3 - Universite de Mediterranee, 163 avenue de Luminy, 13288 Marseille Cedex 09 (France); Akerlof, Carl [Randall Laboratory of Physics, University of Michigan, 450 Church Street, Ann Arbor, MI 48109-1040 (United States); Basa, Stephane [LAM, BP8, Traverse du siphon, 13376 Marseille Cedex 12 (France); Bertin, Vincent [CPPM, CNRS/IN2P3 - Universite de Mediterranee, 163 avenue de Luminy, 13288 Marseille Cedex 09 (France); Boer, Michel [OHP, 04870 Saint Michel de l' Observatoire (France); Brunner, Juergen; Busto, Jose; Dornic, Damien [CPPM, CNRS/IN2P3 - Universite de Mediterranee, 163 avenue de Luminy, 13288 Marseille Cedex 09 (France); Klotz, Alain [OHP, 04870 Saint Michel de l' Observatoire (France); IRAP, 9 avenue du colonel Roche, 31028 Toulouse Cedex 4 (France); Schussler, Fabian; Vallage, Bertrand [CEA-IRFU, centre de Saclay, 91191 Gif-sur-Yvette (France); Vecchi, Manuela [CPPM, CNRS/IN2P3 - Universite de Mediterranee, 163 avenue de Luminy, 13288 Marseille Cedex 09 (France); Zheng, Weikang [Randall Laboratory of Physics, University of Michigan, 450 Church Street, Ann Arbor, MI 48109-1040 (United States)

    2012-11-11

    The ANTARES telescope is well suited to detect neutrinos produced in astrophysical transient sources as it can observe a full hemisphere of the sky at all the times with a duty cycle close to unity and an angular resolution better than 0.5 Degree-Sign . Potential sources include gamma-ray bursts (GRBs), core collapse supernovae (SNe), and flaring active galactic nuclei (AGNs). To enhance the sensitivity of ANTARES to such sources, a new detection method based on coincident observations of neutrinos and optical signals has been developed. A fast online muon track reconstruction is used to trigger a network of small automatic optical telescopes. Such alerts are generated one or two times per month for special events such as two or more neutrinos coincident in time and direction or single neutrinos of very high energy. Since February 2009, ANTARES has sent 37 alert triggers to the TAROT and ROTSE telescope networks, 27 of them have been followed. First results on the optical images analysis to search for GRBs are presented.

  8. Gamma ray observations of the solar system

    International Nuclear Information System (INIS)

    1981-01-01

    Two general categories are discussed concerning the evolution of the solar system: the dualistic view, the planetesimal approach and the monistic view, the nebular hypothesis. The major points of each view are given and the models that are developed from these views are described. Possible applications of gamma ray astronomical observations to the question of the dynamic evolution of the solar system are discussed

  9. Gamma ray observations of the solar system

    Energy Technology Data Exchange (ETDEWEB)

    1981-01-01

    Two general categories are discussed concerning the evolution of the solar system: the dualistic view, the planetesimal approach and the monistic view, the nebular hypothesis. The major points of each view are given and the models that are developed from these views are described. Possible applications of gamma ray astronomical observations to the question of the dynamic evolution of the solar system are discussed.

  10. Gamma ray observations of the solar system

    Science.gov (United States)

    1981-01-01

    Two general categories are discussed concerning the evolution of the solar system: the dualistic view, the planetesimal approach; and the monistic view, the nebular hypothesis. The major points of each view are given and the models that are developed from these views are described. Possible applications of gamma ray astronomical observations to the question of the dynamic evolution of the solar system are discussed.

  11. Atmospheric gamma-ray observation with the BETS detectorfor calibrating atmospheric neutrino flux calculations

    CERN Document Server

    Kasahara, K.; Torii, S.; Tamura, T.; Tateyama, N.; Yoshida, K.; Yamagami, T.; Saito, Y.; Nishimura, J.; Murakami, H.; Kobayashi, T.; Komori, Y.; Honda, M.; Ohuchi, T.; Midorikawa, S.; Yuda, T.

    2002-01-01

    We observed atmospheric gamma-rays around 10 GeV at balloon altitudes (15~25 km) and at a mountain (2770 m a.s.l). The observed results were compared with Monte Carlo calculations to find that an interaction model (Lund Fritiof1.6) used in an old neutrino flux calculation was not good enough for describing the observed values. In stead, we found that two other nuclear interaction models, Lund Fritiof7.02 and dpmjet3.03, gave much better agreement with the observations. Our data will serve for examining nuclear interaction models and for deriving a reliable absolute atmospheric neutrino flux in the GeV region.

  12. Testing the Dark Matter Scenario for PeV Neutrinos Observed in IceCube.

    Science.gov (United States)

    Murase, Kohta; Laha, Ranjan; Ando, Shin'ichiro; Ahlers, Markus

    2015-08-14

    Late time decay of very heavy dark matter is considered as one of the possible explanations for diffuse PeV neutrinos observed in IceCube. We consider implications of multimessenger constraints, and show that proposed models are marginally consistent with the diffuse γ-ray background data. Critical tests are possible by a detailed analysis and identification of the sub-TeV isotropic diffuse γ-ray data observed by Fermi and future observations of sub-PeV γ rays by observatories like HAWC or Tibet AS+MD. In addition, with several-year observations by next-generation telescopes such as IceCube-Gen2, muon neutrino searches for nearby dark matter halos such as the Virgo cluster should allow us to rule out or support the dark matter models, independently of γ-ray and anisotropy tests.

  13. Constraining nuclear data via cosmological observations: Neutrino energy transport and big bang nucleosynthesis

    Directory of Open Access Journals (Sweden)

    Paris Mark

    2017-01-01

    Full Text Available We introduce a new computational capability that moves toward a self-consistent calculation of neutrino transport and nuclear reactions for big bang nucleosynthesis (BBN. Such a self-consistent approach is needed to be able to extract detailed information about nuclear reactions and physics beyond the standard model from precision cosmological observations of primordial nuclides and the cosmic microwave background radiation. We calculate the evolution of the early universe through the epochs of weak decoupling, weak freeze-out and big bang nucleosynthesis (BBN by simultaneously coupling a full strong, electromagnetic, and weak nuclear reaction network with a multi-energy group Boltzmann neutrino energy transport scheme. The modular structure of our approach allows the dissection of the relative contributions of each process responsible for evolving the dynamics of the early universe. Such an approach allows a detailed account of the evolution of the active neutrino energy distribution functions alongside and self-consistently with the nuclear reactions and entropy/heat generation and 'ow between the neutrino and photon/electron/positron/baryon plasma components. Our calculations reveal nonlinear feedback in the time evolution of neutrino distribution functions and plasma thermodynamic conditions. We discuss the time development of neutrino spectral distortions and concomitant entropy production and extraction from the plasma. These e↑ects result in changes in the computed values of the BBN deuterium and helium-4 yields that are on the order of a half-percent relative to a baseline standard BBN calculation with no neutrino transport. This is an order of magnitude larger e↑ect than in previous estimates. For particular implementations of quantum corrections in plasma thermodynamics, our calculations show a 0.4% increase in deuterium and a 0.6% decrease in 4He over our baseline. The magnitude of these changes are on the order of uncertainties

  14. Low energy solar neutrino experiments: The Soviet American Gallium Experiment (SAGE). Final report, August 12, 1988--October 31, 1994

    International Nuclear Information System (INIS)

    1995-01-01

    Two 71 Ga experiments are currently in operation. The first is the 60 ton Soviet American Gallium Experiment (SAGE) at Baksan, which has recently reported a signal level of 73+18/-16(stat)+5/-7(syst) SNU; the second is the 30 ton GALLEX experiment at Gran Sasso, which sees 87±14±7 SNU. Both results are consistent, and both suggest a neutrino flux level low compared to the total expected from standard solar model calculations. It is not possible, however, to make a case for flux levels lower than the p-p prediction. Assuming the experiments are correct (Neutrino source calibrations are planned for both SAGE and GALLEX in the near future.), it is not at all clear yet whether the answer lies with the neutrino physics, solar physics, or a combination of both. Nevertheless, though solar model effects cannot be ruled out, if the Homestake and Kamiokande results are taken at face value, then these two experiments alone imply that neutrino oscillations or some similar particle physics result must be present to some degree. This report reviews the SAGE experiment and recent results. Non-radiochemical experiments are also discussed, with an emphasis on the Kamiokande water Cerenkov results

  15. Low energy solar neutrino experiments: The Soviet American Gallium Experiment (SAGE). Final report, August 12, 1988--October 31, 1994

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-04-01

    Two {sup 71}Ga experiments are currently in operation. The first is the 60 ton Soviet American Gallium Experiment (SAGE) at Baksan, which has recently reported a signal level of 73+18/{minus}16(stat)+5/{minus}7(syst) SNU; the second is the 30 ton GALLEX experiment at Gran Sasso, which sees 87{+-}14{+-}7 SNU. Both results are consistent, and both suggest a neutrino flux level low compared to the total expected from standard solar model calculations. It is not possible, however, to make a case for flux levels lower than the p-p prediction. Assuming the experiments are correct (Neutrino source calibrations are planned for both SAGE and GALLEX in the near future.), it is not at all clear yet whether the answer lies with the neutrino physics, solar physics, or a combination of both. Nevertheless, though solar model effects cannot be ruled out, if the Homestake and Kamiokande results are taken at face value, then these two experiments alone imply that neutrino oscillations or some similar particle physics result must be present to some degree. This report reviews the SAGE experiment and recent results. Non-radiochemical experiments are also discussed, with an emphasis on the Kamiokande water Cerenkov results.

  16. Two Light Sterile Neutrinos that Mix Maximally with Each Other and Moderately with Three Active Neutrinos

    International Nuclear Information System (INIS)

    Krolikowski, W.

    2004-01-01

    Since the 3+1 neutrino models with one light sterile neutrino turn out to be not very effective, at least two light sterile neutrinos may be needed to reconcile the solar and atmospheric neutrino experiments with the LSND result, if this is confirmed by the ongoing MiniBooNE experiment (and when the CPT invariance is assumed to hold for neutrino oscillations). We present an attractive 3+2 neutrino model, where two light sterile neutrinos mix maximally with each other, in analogy to the observed maximal mixing of muon and tauon active neutrinos. But, while the mixing of ν e and (ν μ - ν τ )/√2 is observed as large (though not maximal), the mixing of ν e with the corresponding combination of two light sterile neutrinos is expected to be only moderate because of the reported smallness of LSND oscillation amplitude. The presented model turns out, however, not to be more effective in explaining the hypothetic LSND result than the simplest 3+1 neutrino model. On the other hand, in the considered 3+2 model, the deviations from conventional oscillations of three active neutrinos appear to be minimal within a larger class of 3+2 models. (author)

  17. Three flavour oscillation interpretation of neutrino data

    Indian Academy of Sciences (India)

    To explain the atmospheric neutrino problem in terms of neutrino oscillations, ЖС¾ of about 10-¿. eV. ¾. [8] is needed whereas the neutrino oscil- lation solution to the solar neutrino problem requires ЖС¾ ~10- eV. ¾ . Hence both solar and atmospheric neutrino problems cannot be explained in terms of e ° μ oscillations.

  18. The sun and the neutrinos

    International Nuclear Information System (INIS)

    Forgacsne Dajka, E.

    2000-01-01

    A review of the solar neutrino puzzle is given. The main processes in the sun, the pp-chain and the CNO cycle are described. The solar neutrino puzzle, i.e. the fact that the detected amount of neutrinos coming from the sun is less than the amount predicted by the solar model is discussed. The first generation solar neutrino experiments are presented. (K.A.)

  19. Neutrino mass

    International Nuclear Information System (INIS)

    Robertson, R.G.H.

    1992-01-01

    Despite intensive experimental work since the neutrino's existence was proposed by Pauli 60 years ago, and its first observation by Reines and Cowan almost 40 years ago, the neutrino's fundamental properties remain elusive. Among those properties are the masses of the three known flavors, properties under charge conjugation, parity and time-reversal, and static and dynamic electromagnetic moments. Mass is perhaps the most fundamental, as it constrains the other properties. The present status of the search for neutrino mass is briefly reviewed

  20. Resource Letter OSE-1: Observing Solar Eclipses

    Science.gov (United States)

    Pasachoff, Jay M.; Fraknoi, Andrew

    2017-07-01

    This Resource Letter provides a guide to the available literature, listing selected books, articles, and online resources about scientific, cultural, and practical issues related to observing solar eclipses. It is timely, given that a total solar eclipse will cross the continental United States on August 21, 2017. The next total solar eclipse path crossing the U.S. and Canada will be on April 8, 2024. In 2023, the path of annularity of an annular eclipse will cross Mexico, the United States, and Canada, with partial phases visible throughout those countries.

  1. Final technical report on the development of the Cenenkov[sic] triggered radiochemical solar neutrino detector and the potential for single atom extraction and classification

    CERN Document Server

    Lande, K

    2001-01-01

    The most direct way to search for flavor changing of neutrinos after their generation in the solar core is to compare the solar neutrino detection rate of a purely electron neutrino detector with that of a detector that can detect all neutrino flavors. The ''all flavor'' flux measurement involves nu-e elastic scattering, while the nu sub e flux measurement involves an inverse beta decay detection, such as sup 3 sup 7 Cl(nu sub e , e sup -) sup 3 sup 7 Ar. The interactions due to sup 7 Be neutrinos must be separated FR-om those due to sup 8 B neutrinos. A Cherenkov signal-triggered radiochemical detector is proposed that will allow a very precise determination of both the sup 8 B and sup 7 Be electron neutrino fluxes FR-om the Sun. The basic concept is to identify each sup 8 B electron neutrino interaction in the detector and then sweep out the sup 3 sup 7 Ar atom produced by this sup 8 B neutrino as soon as it is made. A set of photomultipler tubes can be used to detect the Ar atom production and immediately ...

  2. Solar Observations on Magneto-Convection

    Science.gov (United States)

    1989-05-31

    Technical Library National Solar Observatory Sunspot, NM 88349 Karl - Schwarzschild -Strasse 1 8046 Garching bei Mundhen Solar Observations On Magneto...Schmidt, Hermann-Ulrich Schmidt, Hans-Christoph Thomas (eds.) Max-Planck-Institut fir Physik und Astrophysik Institut fiur Astrophysik Karl ... Schwarzschild -St-. 1 D-8046 Garching, FklG 14TIS CRiA.&l DTIC TA. U~Jar,iou8:ed B ......... ... Distribution I -- Availability COcý----- Avail and or Dist special

  3. Energy-dependent solar neutrino flux depletion in the exact parity model and implications for SNO, SuperKamiokande and BOREXINO

    International Nuclear Information System (INIS)

    Volkas, R.R.; Wong, Y.Y.Y.

    1998-03-01

    Energy-dependent solar neutrino flux reduction caused by the Mikheyev-Smirnov-Wolfenstein (MSW) effect is applied to the Exact Parity Model. Several scenarios are possible, depending on the region of parameter space chosen. The interplay between intergenerational MSW transitions and vacuum 'intragenerational' ordinary-mirror neutrino oscillations is discussed. Expectations for the ratio of charged to neutral current event rates at the Sudbury Neutrino Observatory (SNO) are estimated. The implications of the various scenarios for the Boron neutrino energy spectrum and BOREXINO are briefly discussed. The consequences of MSW-induced solar neutrino depletion within the Exact Parity Model differ in interesting ways from the standard ν e ↔ ν μ,τ and ν e ↔ ν s cases. The physical causes of these differences are determined. (authors)

  4. Observation of a visible charmed particle decay in neutrino interactions

    International Nuclear Information System (INIS)

    Cnops, A.M.; Connolly, P.L.; Kahn, S.A.

    1979-01-01

    In a sample of 250 semileptonic charmed particle decays (ν/sub μ/ + Neon → μ - + e + + ... events), one clear event is found where the e + does not come directly from the ν interaction vertex but from a decay point 1.1 cm downstream of the vertex. This event is interpreted as a visible charmed particle decay: into an e + and a positive and a negative charged track. The observation of a visible charm decay in the sample is consistent with what is expected if the charm lifetime were of the order 5 x 10 -13 sec. 5 references

  5. Neutrinos: Theory and Phenomenology

    Energy Technology Data Exchange (ETDEWEB)

    Parke, Stephen

    2013-10-22

    The theory and phenomenology of neutrinos will be addressed, especially that relating to the observation of neutrino flavor transformations. The current status and implications for future experiments will be discussed with special emphasis on the experiments that will determine the neutrino mass ordering, the dominant flavor content of the neutrino mass eigenstate with the smallest electron neutrino content and the size of CP violation in the neutrino sector. Beyond the neutrino Standard Model, the evidence for and a possible definitive experiment to confirm or refute the existence of light sterile neutrinos will be briefly discussed.

  6. The search for possible time variations in Davis' measurements of the argon production rate in the solar neutrino experiment

    International Nuclear Information System (INIS)

    Haubold, H.J.; Gerth, E.

    1985-01-01

    With the gradual accumulation of experimental data in the solar neutrino experiment of Davis and collaborators (runs 18-74 for 1970-1982), the question, whether there are time variations of the solar neutrino flux, is of renewed interest. We discuss the mathematical-numerical methods applied to the statistical analysis of Davis' argon-37 production rate up till now known in the literature. These methods are characterized by the arbitrary arrangement of the Davis data in a time series. We perform a certain Fourier transformation for unequally-spaced time series of the measuring data of the argon-37 production rate, discuss the discovered periods and give significance criteria with respect to each period. We find that all periods discussed in the literature are contained in our series of periods. Pointing out the more mathematical character of the time series analysis we emphasize the predominant significance of the detected periods. (author)

  7. Neutrino disintegration of deuterium

    International Nuclear Information System (INIS)

    Ying, S.; Haxton, W.; Henley, E.M.

    1989-01-01

    We calculate the rate of both neutral- and charged-current neutrino and antineutrino disintegration of deuterium. These rates are of interest for solar 8 B and hep ( 3 He + p) spectra and supernovae neutrinos, and are relevant for the Sudbury Neutrino Observatory (SNO)

  8. Evidence for neutrino oscillations in the Sudbury Neutrino Observatory

    International Nuclear Information System (INIS)

    Marino, Alysia Diane

    2004-01-01

    The Sudbury Neutrino Observatory (SNO) is a large-volume heavy water Cerenkov detector designed to resolve the solar neutrino problem. SNO observes charged-current interactions with electron neutrinos, neutral-current interactions with all active neutrinos, and elastic-scattering interactions primarily with electron neutrinos with some sensitivity to other flavors. This dissertation presents an analysis of the solar neutrino flux observed in SNO in the second phase of operation, while ∼2 tonnes of salt (NaCl) were dissolved in the heavy water. The dataset here represents 391 live days of data. Only the events above a visible energy threshold of 5.5 MeV and inside a fiducial volume within 550 cm of the center of the detector are studied. The neutrino flux observed via the charged-current interaction is [1.71 ± 0.065(stat.)± 0.068 0.065 (sys.)±0.02(theor.)] x 10 6 cm -2 s -1 , via the elastic-scattering interaction is [2.21±0.22(stat.)± 0.12 0.11 (sys.)±0.01(theor.)] x 10 6 cm -2 s -1 , and via the neutral-current interaction is [5.05±0.23(stat.)± 0.37 0.31 (sys.)±0.06(theor.)] x 10 6 cm -2 s -1 . The electron-only flux seen via the charged-current interaction is more than 7σ below the total active flux seen via the neutral-current interaction, providing strong evidence that neutrinos are undergoing flavor transformation as they travel from the core of the Sun to the Earth. The most likely origin of the flavor transformation is matter-induced flavor oscillation

  9. Evidence for neutrino oscillations in the Sudbury Neutrino Observatory

    Energy Technology Data Exchange (ETDEWEB)

    Marino, Alysia Diane [Univ. of California, Berkeley, CA (United States)

    2004-01-01

    The Sudbury Neutrino Observatory (SNO) is a large-volume heavy water Cerenkov detector designed to resolve the solar neutrino problem. SNO observes charged-current interactions with electron neutrinos, neutral-current interactions with all active neutrinos, and elastic-scattering interactions primarily with electron neutrinos with some sensitivity to other flavors. This dissertation presents an analysis of the solar neutrino flux observed in SNO in the second phase of operation, while ~2 tonnes of salt (NaCl) were dissolved in the heavy water. The dataset here represents 391 live days of data. Only the events above a visible energy threshold of 5.5 MeV and inside a fiducial volume within 550 cm of the center of the detector are studied. The neutrino flux observed via the charged-current interaction is [1.71 ± 0.065(stat.)±$0.065\\atop{0.068}$(sys.)±0.02(theor.)] x 106cm-2s-1, via the elastic-scattering interaction is [2.21±0.22(stat.)±$0.12\\atop{0.11}$(sys.)±0.01(theor.)] x 106cm-2s-1, and via the neutral-current interaction is [5.05±0.23(stat.)±$0.31\\atop{0.37}$(sys.)±0.06(theor.)] x 106cm-2s-1. The electron-only flux seen via the charged-current interaction is more than 7σ below the total active flux seen via the neutral-current interaction, providing strong evidence that neutrinos are undergoing flavor transformation as they travel from the core of the Sun to the Earth. The most likely origin of the flavor transformation is matter-induced flavor oscillation.

  10. Neutrino mass and mixing, and non-accelerator experiments

    International Nuclear Information System (INIS)

    Robertson, R.G.H.

    1992-01-01

    We review the current status of experimental knowledge about neutrinos derived from kinematic mass measurements, neutrino oscillation searches at reactors and accelerators, solar neutrinos, atmospheric neutrinos, and single and double beta decay. The solar neutrino results yield fairly strong and consistent indication that neutrino oscillations are occurring. Other evidence for new physics is less consistent and convincing

  11. The experimental status of neutrino masses and mixings

    International Nuclear Information System (INIS)

    Robertson, R.G.H.

    1992-01-01

    We review the current status of experimental knowledge about neutrinos derived from kinematic mass measurements, neutrino oscillation searches at reactors and accelerators, solar neutrinos, atmospheric neutrinos, and single and double beta decay. The solar neutrino results yield fairly strong and consistent indications that neutrino oscillations are occurring. Other evidence for new physics is less consistent and convincing

  12. Supersonic turbulent convection, inhomogeneities of chemical composition and the solar neutrino problem

    International Nuclear Information System (INIS)

    Prentice, A.J.R.; Monash Univ., Clayton

    1976-01-01

    A new theory of the evolution of the Sun is presented to account for the present low flux of neutrinos. It is suggested that resistive segregation of grain material during the early stages of star formation, followed by a turbulent phase of planetary formation, may lead to an initial chemically inhomogeneous Sun consisting of a small metal-rich core of mass 0.03 M(Sun) surrounded by a homogeneous, but slightly metal-deficient, radiatively stable envelope. Because of its high Z we propose that the core was highly convectively unstable and a large supersonic turbulent stress was created by the motions of long and needle-like overshooting convective elements. This stress greatly expands the volume of the core causing it to become hotter at the centre but cooler at its edge. The net result is a star of quite low luminosity which consumes its central hydrogen very rapidly, via the CNO cycle, with hardly any burning taking place in the surrounding envelope. After a time tsub(0), comparable with but less than 4.7 x 10 9 yr, we propose that the core burns itself out. The whole star then undergoes a massive structural change with the luminosity suddenly increasing from about 1/2 L(Sun) to close to L(Sun). The net result at solar age is the configuration which has a small burnt-out core, a barely consumed hydrogen-rich envelope, and a greatly reduced neutrino flux of order 1 SNU. Setting tsub(0) = 4.13 x 10 9 yr, our theory provided a natural explanation of the disappearance of the Great Infra-Cambrian Ice Age and mysterious onset of the Gambrian Period, some 570 m. yr ago. It may also, possibly, account for the 'turn-off' gaps in the colour-magnitude diagram of old galactic clusters. (orig.) [de

  13. EXPLOSIVE NUCLEOSYNTHESIS IN THE NEUTRINO-DRIVEN ASPHERICAL SUPERNOVA EXPLOSION OF A NON-ROTATING 15 Msun STAR WITH SOLAR METALLICITY

    International Nuclear Information System (INIS)

    Fujimoto, Shin-ichiro; Kotake, Kei; Hashimoto, Masa-aki; Ono, Masaomi; Ohnishi, Naofumi

    2011-01-01

    We investigate explosive nucleosynthesis in a non-rotating 15 M sun 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 a mass number ≤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 a low-mode SASI. The abundance pattern of the SN ejecta is similar to that of the solar system for models whose masses range between (0.4-0.5) M sun of the ejecta from the inner region (≤10, 000 km) of the precollapse core. For the models, the explosion energies and the 56 Ni masses are ≅ 10 51 erg and (0.05-0.06) M sun , respectively; their estimated baryonic masses of the neutron star are comparable to the ones observed in neutron-star binaries. These findings may have little uncertainty because most of the ejecta is composed of matter that is heated via the shock wave and has relatively definite abundances. The abundance ratios for Ne, Mg, Si, and Fe observed in the Cygnus loop are reproduced well with the SN ejecta from an inner region of the 15 M sun progenitor.

  14. Coherent scattering of neutrinos and antineutrinos by quarks in a crystal

    International Nuclear Information System (INIS)

    Weber, J.; Wilmot, G.

    1988-01-01

    An earlier paper presented the theory of a method for observation of neutrinos and antineutrinos. The method gives large cross sections. In this paper the theory is extended for a crystal with nuclei described by the modern theory of quarks. Results of experiments with a tritium antineutrino source, a nuclear reactor, and solar neutrinos are presented. Solar neutrinos lead to a positive result for the Eotvos experiment, for equal torsion balance masses composed of materials with different Debye temperatures

  15. 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 ...

  16. Again on neutrino oscillations

    International Nuclear Information System (INIS)

    Bilenky, S.M.; Pontecorvo, B.

    1976-01-01

    The general case is treated of a weak interaction theory in which a term violating lepton charges is present. In such a scheme the particles with definite masses are Majorana neutrinos (2N if in the weak interaction participate N four-component neutrinos). Neutrino oscillations are discussed and it is shown that the minimum average intensity at the earth of solar neutrinos is 1/2N of the intensity expected when oscillations are absent

  17. Neutrino masses and mixings

    International Nuclear Information System (INIS)

    Wolfenstein, L.

    1991-01-01

    Theoretical prejudices, cosmology, and neutrino oscillation experiments all suggest neutrino mass are far below present direct experimental limits. Four interesting scenarios and their implications are discussed: (1) a 17 keV ν τ , (2) a 30 ev ν τ making up the dark matter, (3) a 10 -3 ev ν μ to solve the solar neutrino problem, and (4) a three-neutrino MSW solution

  18. Evidence and Search for Sterile Neutrinos at Accelerators

    Directory of Open Access Journals (Sweden)

    W. C. Louis

    2013-01-01

    Full Text Available The LSND short-baseline neutrino experiment has published evidence for antineutrino oscillations at a mass scale of ~1 eV2. The MiniBooNE experiment, designed to test this evidence for oscillations at an order of magnitude higher neutrino energy and distance, observes excesses of events in both neutrino mode and antineutrino mode. While the MiniBooNE neutrino excess has a neutrino energy spectrum that is softer than expected from LSND, the MiniBooNE antineutrino excess is consistent with neutrino oscillations and with the LSND oscillation signal. When combined with oscillation measurements at the solar and atmospheric mass scales, assuming that the LSND and MiniBooNE signals are due to neutrino oscillations, these experiments imply the existence of more than three neutrino mass states and, therefore, one or more sterile neutrinos. Such sterile neutrinos, if proven to exist, would have a big impact on particle physics, nuclear physics, and astrophysics and would contribute to the dark matter of the universe. Future experiments under construction or proposed at Fermilab, ORNL, CERN, and in Japan will provide a definitive test of short-baseline neutrino oscillations and will have the capability of proving the existence of sterile neutrinos.

  19. Neutrino physics in heaven

    International Nuclear Information System (INIS)

    Raffelt, G.

    2005-01-01

    After a brief overview of the usual topics that connect astrophysics and cosmology with neutrino physics I will focus on two main themes. First, what can we learn from the neutrino signal of a future galactic supernova, in particular about the neutrino mass ordering. Second, what can we learn about neutrino properties from cosmological observables, notably about the neutrino absolute mass scale from cosmological large-scale structure observables. (author)

  20. Observations spotted solar type stars in Pleiades

    International Nuclear Information System (INIS)

    Magnitskij, A.K.

    1987-01-01

    The september - october 1986 observations discovered periodic light variations in three solar type stars in the Pleiades cluster: Hz 296 (0.8 M Sun ), Hz152(0.91 M Sun ) and Hz739(1.15 M Sun ). Periods and amplitudes are accordingly 2 d and 0 m .11, 4 d .12 and 0 m .07, 2 d .70 and 0 m .05. Considerable light variations of these stars in Pleiades are due to the rotation of spotted stars. Contrast spots of solar type stars likely exist when stars are young and rapidly rotate

  1. Inclusive observables and hard gluon emission in neutrino deep inelastic scattering

    International Nuclear Information System (INIS)

    Bouchiat, C.; Meyer, P.; Mezard, M.

    1980-01-01

    We derive the predictions of perturbative QCD together with non-perturbative corrections for a set of inclusive observables connected with the angular distribution of light-cone energy in deep inelastic neutrino scattering. Our particular choice of observables has been made in order to meet important physical requirements besides the necessary condition of infrared regularity. Our inclusive observables receive their dominant contribution from the quark fragmentation region. The non-perturbative contribution is calculable in a rather model-independent way and stays at an acceptable level in realistic experimental conditions. The QCD perturbative contribution, which takes the simple form of a convolution product, exhibits a strongly decreasing behaviour as a function of the Bjorken scaling variable x, superimposed on a constant background associated with the non-perturbative terms, allowing a rather clean separation of the two effects. The perturbative term being dominated by the process of hard-gluon emission, an experimental investigation of the observables discussed here may be a good way to detect the effect of gluon emission in deep inelastic neutrino scattering. (orig.)

  2. Workshop on low energy neutrino physics

    International Nuclear Information System (INIS)

    2009-01-01

    The main topics of the workshop are: the determination of the neutrino mixing angle theta-13, the experiments concerning the monitoring of reactors based on the measurement of neutrino spectra, solar neutrinos, supernovae neutrinos, geo-neutrinos, neutrino properties, neutrinoless double beta decay and future low energy neutrino detectors. This document gathers together the program of the workshop, the slides of the presentations, some abstracts and some posters

  3. Enrichment services for chromium isotopes for the GALLEX (gallium experiment) international collaboration experiment on solar neutrino flux

    Science.gov (United States)

    Szady, Andrew J.

    1990-07-01

    Detailed discussions were held with members of the Gallium Experiment (GALLEX) international solar neutrino research collaboration concerning negotiations to provide $1.4 million in services to enrich (50)Cr for a (51)Cr neutrino source. The source will be used to calibrate the 20-ton gallium solar neutrino detector currently in place in the Gran Sasso Laboratory in Italy. Funding approval for the enrichment services is expected from the European Common Market by October 19, 1990. The discussions focused on the technical aspects of the enrichment, the health and safety requirements for handling the process gas, cost projections, schedule, the Work-for-Others contract, and the method of payment. Discussions were also held with members of the Nuclear Physics Dept. at the University of Milan concerning the availability of isotopes enriched by the Calutron at the Oak Ridge National Laboratory. Very high purity material is needed to grow crystals for use in double beta decay detectors. Finally, working sessions were held to draft a coauthored paper on the results of using the gas centrifuge to remove trace quantities of (85)Kr from natural xenon.

  4. Introduction to massive neutrinos

    International Nuclear Information System (INIS)

    Kayser, B.

    1984-01-01

    We discuss the theoretical ideas which make it natural to expect that neutrinos do indeed have mass. Then we focus on the physical consequences of neutrino mass, including neutrino oscillation and other phenomena whose observation would be very interesting, and would serve to demonstrate that neutrinos are indeed massive. We comment on the legitimacy of comparing results from different types of experiments. Finally, we consider the question of whether neutrinos are their own antiparticles. We explain what this question means, discuss the nature of a neutrino which is its own antiparticles, and consider how one might determine experimentally whether neutrinos are their own antiparticles or not

  5. Workshop: Neutrino telescopes

    International Nuclear Information System (INIS)

    Anon.

    1990-01-01

    Despite being the most elusive of the known particles, neutrinos provide vital new physics insights. Most neutrino knowledge so far has come from studies using beams from reactors and accelerators, but in recent years important new contributions have resulted from investigation of natural neutrinos from cosmic rays, nearby stars (the sun), or distant sources, such as the 1987 supernova. The supernova observations marked the start of a new era in neutrino astronomy, but neutrino telescopes were anyway assured of an important ongoing role

  6. Workshop: Neutrino telescopes

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1990-05-15

    Despite being the most elusive of the known particles, neutrinos provide vital new physics insights. Most neutrino knowledge so far has come from studies using beams from reactors and accelerators, but in recent years important new contributions have resulted from investigation of natural neutrinos from cosmic rays, nearby stars (the sun), or distant sources, such as the 1987 supernova. The supernova observations marked the start of a new era in neutrino astronomy, but neutrino telescopes were anyway assured of an important ongoing role.

  7. Impact of Massive Neutrinos and Dark Radiation on the High-redshift Cosmic Web. I. Lyα Forest Observables

    Science.gov (United States)

    Rossi, Graziano

    2017-11-01

    With upcoming high-quality data from surveys such as the Extended Baryon Oscillation Spectroscopic Survey or the Dark Energy Spectroscopic Instrument, improving the theoretical modeling and gaining a deeper understanding of the effects of neutrinos and dark radiation on structure formation at small scales are necessary, to obtain robust constraints free from systematic biases. Using a novel suite of hydrodynamical simulations that incorporate dark matter, baryons, massive neutrinos, and dark radiation, we present a detailed study of their impact on Lyα forest observables. In particular, we accurately measure the tomographic evolution of the shape and amplitude of the small-scale matter and flux power spectra and search for unique signatures along with preferred scales where a neutrino mass detection may be feasible. We then investigate the thermal state of the intergalactic medium (IGM) through the temperature-density relation. Our findings suggest that at k˜ 5 h {{Mpc}}-1 the suppression on the matter power spectrum induced by \\sum {m}ν =0.1 {eV} neutrinos can reach ˜ 4 % at z˜ 3 when compared to a massless neutrino cosmology, and ˜ 10 % if a massless sterile neutrino is included; surprisingly, we also find good agreement (˜ 2 % ) with some analytic predictions. For the 1D flux power spectrum {P}{ F }1{{D}}, the highest response to free-streaming effects is achieved at k˜ 0.005 {[{km}/{{s}}]}-1 when \\sum {m}ν =0.1 {eV}; this k-limit falls in the Lyα forest regime, making the small-scale {P}{ F }1{{D}} an excellent probe for detecting neutrino and dark radiation imprints. Our results indicate that the IGM at z˜ 3 provides the best sensitivity to active and sterile neutrinos.

  8. Development of a radio-detection array for the observation of UHE neutrino-induced showers

    Energy Technology Data Exchange (ETDEWEB)

    Ardouin, Daniel [SUBATECH, IN2P3-CNRS, University of Nantes, E. Mines Nantes, Nantes (France)], E-mail: Daniel.ardouin@univ-nantes.fr; Charrier, Didier; Lautridou, Pascal [SUBATECH, IN2P3-CNRS, University of Nantes, E. Mines Nantes, Nantes (France); Martineau-Huynh, Olivier [LPNHE, IN2P3-CNRS, University of Paris VI, Paris (France); Ravel, Olivier [SUBATECH, IN2P3-CNRS, University of Nantes, E. Mines Nantes, Nantes (France); Wu Xiangping; Zhao Meng [NAOC, Beijing (China)

    2009-06-01

    The recent demonstration by the CODALEMA collaboration of the ability of the radio-detection technique for the characterization of ultra-high-energy cosmic-rays (UHECR) calls for the use of this powerful method for the observation of UHE neutrinos. For this purpose, an adaptation of the already existing 21CM-Array (CMA) in China, is presently under achievement. In an exceptionally low electromagnetic noise level, 10160 log-periodic 50-200 MHz antennas sit along two high-altitude valleys, surrounded by mountain chains. This layout results in 30-60 km effective rock thicknesses for {nu} interactions with low incidence trajectories along the direction of two 4-6 km baselines. We will present first in-situ radio measurements demonstrating that this environment shows particularly favourable physical conditions for the observation of electromagnetic decay signals of {tau}'s leptons originating from the interaction of 10{sup 17-20} eV {nu}{sub {tau}} neutrinos.

  9. Development of a radio-detection array for the observation of UHE neutrino induced showers

    Energy Technology Data Exchange (ETDEWEB)

    Ardouin, D.; Charrier, D.; Lautridou, P.; Ravel, O. [Nantes Univ., E.Mines, SUBATECH, IN2P3-CNRS, 44 (France); Martineau-Huynh, O. [Paris-6 Univ., LPNHE, IN2P3-CNRS, 75 (France). Lab. de Physique Nucleaire et de Hautes Energies; Xiang-Ping, Wu; Meng, Zhao [NAOC, Beijing (China)

    2008-07-01

    The recent demonstration by the CODALEMA Collaboration of the ability of the radio-detection technique for the characterization of ultra-high energy cosmic-rays (UHECR) calls for the use of this powerful method for the observation of UHE neutrinos. For this purpose, an adaptation of the already existing 21CM-Array in China, is presently under achievement. In an exceptionally low electromagnetic noise level, 10160 log-periodic 50-200 MHz antennas sit along two high altitude valleys, surrounded by mountain chains. This lay-out results in 30-60 km effective rock thicknesses for {nu} interactions with low incidence trajectories along the direction of two 4-6 km baselines. We will present first in-situ radio measurements demonstrating that this environment shows particularly favourable physical conditions for the observation of electromagnetic decay signals of {tau}'s leptons originating from the interaction of 10{sup 17-20} eV {nu}{sub {tau}} neutrinos. (authors)

  10. Minimalistic Neutrino Mass Model

    CERN Document Server

    De Gouvêa, A; Gouvea, Andre de

    2001-01-01

    We consider the simplest model which solves the solar and atmospheric neutrino puzzles, in the sense that it contains the smallest amount of beyond the Standard Model ingredients. The solar neutrino data is accounted for by Planck-mass effects while the atmospheric neutrino anomaly is due to the existence of a single right-handed neutrino at an intermediate mass scale between 10^9 GeV and 10^14 GeV. Even though the neutrino mixing angles are not exactly predicted, they can be naturally large, which agrees well with the current experimental situation. Furthermore, the amount of lepton asymmetry produced in the early universe by the decay of the right-handed neutrino is very predictive and may be enough to explain the current baryon-to-photon ratio if the right-handed neutrinos are produced out of thermal equilibrium. One definitive test for the model is the search for anomalous seasonal effects at Borexino.

  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. Study of neutrino production in the Cannonball model of Gamma ray bursts: possibility of observation of these neutrinos with the Antares neutrinos telescope, and study of the optical background recorded with the prototype sector line

    International Nuclear Information System (INIS)

    Ferry, S.

    2004-09-01

    ANTARES is a future neutrino telescope which will be build at 40 km off the french coast (Toulon), at a 2500 m depth. The interaction of a neutrino with matter produces a muon which emits Cerenkov light while propagating in water. This light is detected with 900 photomultipliers distributed over 12 lines. Gamma ray bursts (GRB) are violent cosmological phenomenon observed once per day. In the Cannonball Model, bursts are produced by the interaction of a jet made of cannonballs (CB) with a supernova remnant (SNR). Forward shocks propagate in the SNR, reverse ones in the CB and neutrinos are produced at the shock fronts. An estimation of the neutrino production is given and is studied over a large parameter range. For a typical GRB, 0.002 to 0.3 v μ , cm -2 can be produced. Depending on the viewing angle, ANTARES could detect 1 to 10 v μ per year in correlation with GRBs. The ambient optical background has been recorded by the ANTARES prototype sector line. The analysis is about the background influence on the detector performance and about the organisms activity which produces it. For example, it appears a 17.6 to 20.4 h periodicity which is compatible with the liquid masses movement imposed by the Coriolis force at the ANTARES latitude. (author)

  13. Neutrino Oscillations as a Probe of Light Scalar Dark Matter.

    Science.gov (United States)

    Berlin, Asher

    2016-12-02

    We consider a class of models involving interactions between ultralight scalar dark matter and standard model neutrinos. Such couplings modify the neutrino mass splittings and mixing angles to include additional components that vary in time periodically with a frequency and amplitude set by the mass and energy density of the dark matter. Null results from recent searches for anomalous periodicities in the solar neutrino flux strongly constrain the dark matter-neutrino coupling to be orders of magnitude below current and projected limits derived from observations of the cosmic microwave background.

  14. Accelerator studies of neutrino oscillations

    CERN Document Server

    Ereditato, A

    2000-01-01

    The question of whether the neutrino has a non-vanishing mass plays acrucial role in particle physics. A massive neutrino would unambiguously reveal the existence of new physics beyond the Standard Model. In addition, it could have profound implications on astrophysics and cosmology, with effects on the evolution of the Universe. Experiments aiming at direct neutrino-mass measurements based on kinematics have not been able, so far, to measure the very small neutrino mass. Indirect measurements can be performed by exploiting reactions which may only occur for massive neutrinos. Neutrino oscillation is one of those processes. The mass difference between neutrino mass-eigenstates can be inferred from a phase measurement. This feature allows for high sensitivity experiments. Neutrinos from different sources can be used to search for oscillations: solar neutrinos, neutrinos produced in the interaction of cosmic rays with the atmosphere and artificially produced neutrinos from nuclear reactors and particle accelera...

  15. Integrated Access to Solar Observations With EGSO

    Science.gov (United States)

    Csillaghy, A.

    2003-12-01

    {\\b Co-Authors}: J.Aboudarham (2), E.Antonucci (3), R.D.Bentely (4), L.Ciminiera (5), A.Finkelstein (4), J.B.Gurman(6), F.Hill (7), D.Pike (8), I.Scholl (9), V.Zharkova and the EGSO development team {\\b Institutions}: (2) Observatoire de Paris-Meudon (France); (3) INAF - Istituto Nazionale di Astrofisica (Italy); (4) University College London (U.K.); (5) Politecnico di Torino (Italy), (6) NASA Goddard Space Flight Center (USA); (7) National Solar Observatory (USA); (8) Rutherford Appleton Lab. (U.K.); (9) Institut d'Astrophysique Spatial, Universite de Paris-Sud (France) ; (10) University of Bradford (U.K) {\\b Abstract}: The European Grid of Solar Observations is the European contribution to the deployment of a virtual solar observatory. The project is funded under the Information Society Technologies (IST) thematic programme of the European Commission's Fifth Framework. EGSO started in March 2002 and will last until March 2005. The project is categorized as a computer science effort. Evidently, a fair amount of issues it addresses are general to grid projects. Nevertheless, EGSO is also of benefit to the application domains, including solar physics, space weather, climate physics and astrophysics. With EGSO, researchers as well as the general public can access and combine solar data from distributed archives in an integrated virtual solar resource. Users express queries based on various search parameters. The search possibilities of EGSO extend the search possibilities of traditional data access systems. For instance, users can formulate a query to search for simultaneous observations of a specific solar event in a given number of wavelengths. In other words, users can search for observations on the basis of events and phenomena, rather than just time and location. The software architecture consists of three collaborating components: a consumer, a broker and a provider. The first component, the consumer, organizes the end user interaction and controls requests

  16. Dark matter vs. neutrinos: the effect of astrophysical uncertainties and timing information on the neutrino floor

    International Nuclear Information System (INIS)

    Davis, Jonathan H.

    2015-01-01

    Future multi-tonne Direct Detection experiments will be sensitive to solar neutrino induced nuclear recoils which form an irreducible background to light Dark Matter searches. Indeed for masses around 6 GeV the spectra of neutrinos and Dark Matter are so similar that experiments are said to run into a neutrino floor, for which sensitivity increases only marginally with exposure past a certain cross section. In this work we show that this floor can be overcome using the different annual modulation expected from solar neutrinos and Dark Matter. Specifically for cross sections below the neutrino floor the DM signal is observable through a phase shift and a smaller amplitude for the time-dependent event rate. This allows the exclusion power to be improved by up to an order of magnitude for large exposures. In addition we demonstrate that, using only spectral information, the neutrino floor exists over a wider mass range than has been previously shown, since the large uncertainties in the Dark Matter velocity distribution make the signal spectrum harder to distinguish from the neutrino background. However for most velocity distributions it can still be surpassed using timing information, and so the neutrino floor is not an absolute limit on the sensitivity of Direct Detection experiments

  17. Observational constraints on multimessenger sources of gravitational waves and high-energy neutrinos.

    Science.gov (United States)

    Bartos, Imre; Finley, Chad; Corsi, Alessandra; Márka, Szabolcs

    2011-12-16

    Many astronomical sources of intense bursts of photons are also predicted to be strong emitters of gravitational waves (GWs) and high-energy neutrinos (HENs). Moreover some suspected classes, e.g., choked gamma-ray bursts, may only be identifiable via nonphoton messengers. Here we explore the reach of current and planned experiments to address this question. We derive constraints on the rate of GW and HEN bursts based on independent observations by the initial LIGO and Virgo GW detectors and the partially completed IceCube (40-string) HEN detector. We then estimate the reach of joint GW+HEN searches using advanced GW detectors and the completed km(3) IceCube detector to probe the joint parameter space. We show that searches undertaken by advanced detectors will be capable of detecting, constraining, or excluding, several existing models with 1 yr of observation. © 2011 American Physical Society

  18. Open Surface Solar Irradiance Observations - A Challenge

    Science.gov (United States)

    Menard, Lionel; Nüst, Daniel; Jirka, Simon; Maso, Joan; Ranchin, Thierry; Wald, Lucien

    2015-04-01

    The newly started project ConnectinGEO funded by the European Commission aims at improving the understanding on which environmental observations are currently available in Europe and subsequently providing an informational basis to close gaps in diverse observation networks. The project complements supporting actions and networking activities with practical challenges to test and improve the procedures and methods for identifying observation data gaps, and to ensure viability in real world scenarios. We present a challenge on future concepts for building a data sharing portal for the solar energy industry as well as the state of the art in the domain. Decision makers and project developers of solar power plants have identified the Surface Solar Irradiance (SSI) and its components as an important factor for their business development. SSI observations are crucial in the process of selecting suitable locations for building new plants. Since in-situ pyranometric stations form a sparse network, the search for locations starts with global satellite data and is followed by the deployment of in-situ sensors in selected areas for at least one year. To form a convincing picture, answers must be sought in the conjunction of these EO systems, and although companies collecting SSI observations are willing to share this information, the means to exchange in-situ measurements across companies and between stakeholders in the market are still missing. We present a solution for interoperable exchange of SSI data comprising in-situ time-series observations as well as sensor descriptions based on practical experiences from other domains. More concretely, we will apply concepts and implementations of the Sensor Web Enablement (SWE) framework of the Open Geospatial Consortium (OGC). The work is based on an existing spatial data infrastructure (SDI), which currently comprises metadata, maps and coverage data, but no in-situ observations yet. This catalogue is already registered in the

  19. A combined treatment of neutrino decay and neutrino oscillations

    International Nuclear Information System (INIS)

    Lindner, Manfred; Ohlsson, Tommy; Winter, Walter

    2001-01-01

    Neutrino decay in vacuum has often been considered as an alternative to neutrino oscillations. Because nonzero neutrino masses imply the possibility of both neutrino decay and neutrino oscillations, we present a model-independent formal treatment of these combined scenarios. For that, we show for the example of Majoron decay that in many cases decay products are observable and may even oscillate. Furthermore, we construct a minimal scenario in which we study the physical implications of neutrino oscillations with intermediate decays

  20. Sterile neutrinos beyond LSND at the neutrino factory

    International Nuclear Information System (INIS)

    Meloni, Davide; Tang Jian; Winter, Walter

    2010-01-01

    We discuss the effects of one additional sterile neutrino at the Neutrino Factory. Compared to earlier analyses, which have been motivated by Liquid Scintillator Neutrino Detector (LSND) results, we do not impose any constraint on the additional mass squared splitting. This means that the additional mass eigenstate could, with small mixings, be located among the known ones, as it is suggested by the recent analysis of cosmological data. We use a self-consistent framework at the Neutrino Factory without any constraints on the new parameters. We demonstrate for a combined short and long baseline setup that near detectors can provide the expected sensitivity at the LSND-motivated Δm 41 2 -range, while some sensitivity can also be obtained in the region of the atmospheric mass splitting from the long baselines. We point out that limits on such very light sterile neutrinos may also be obtained from a reanalysis of atmospheric and solar neutrino oscillation data, as well as from supernova neutrino observations. In the second part of the analysis, we compare our sensitivity with the existing literature using additional assumptions, such as |Δm 41 2 |>>|Δm 31 2 |, leading to averaging of the fast oscillations in the far detectors. We demonstrate that while the Neutrino Factory has excellent sensitivity compared to existing studies using similar assumptions, one has to be very careful interpreting these results for a combined short and long baseline setup where oscillations could occur in the near detectors. We also test the impact of additional ν τ detectors at the short and long baselines, and we do not find a substantial improvement of the sensitivities.

  1. Sudbury neutrino observatory proposal

    International Nuclear Information System (INIS)

    Ewan, G.T.; Evans, H.C.; Lee, H.W.

    1987-10-01

    This report is a proposal by the Sudbury Neutrino Observatory (SNO) collaboration to develop a world class laboratory for neutrino astrophysics. This observatory would contain a large volume heavy water detector which would have the potential to measure both the electron-neutrino flux from the sun and the total solar neutrino flux independent of neutrino type. It will therefore be possible to test models of solar energy generation and, independently, to search for neutrino oscillations with a sensitivity many orders of magnitude greater than that of terrestrial experiments. It will also be possible to search for spectral distortion produced by neutrino oscillations in the dense matter of the sun. Finally the proposed detector would be sensitive to neutrinos from a stellar collapse and would detect neutrinos of all types thus providing detailed information on the masses of muon- and tau-neutrinos. The neutrino detector would contain 1000 tons of D20 and would be located more than 2000 m below ground in the Creighton mine near Sudbury. The operation and performance of the proposed detector are described and the laboratory design is presented. Construction schedules and responsibilities and the planned program of technical studies by the SNO collaboration are outlined. Finally, the total capital cost is estimated to be $35M Canadian and the annual operating cost, after construction, would be $1.8 M Canadian, including the insurance costs of the heavy water

  2. OBSERVATIONAL SEARCH FOR PeV-EeV TAU NEUTRINO FROM GRB081203A

    International Nuclear Information System (INIS)

    Aita, Y.; Aoki, T.; Asaoka, Y.; Chonan, T.; Jobashi, M.; Masuda, M.; Morimoto, Y.; Noda, K.; Sasaki, M.; Asoh, J.; Ishikawa, N.; Ogawa, S.; Learned, J. G.; Matsuno, S.; Olsen, S.; Binder, P.-M.; Hamilton, J.; Sugiyama, N.; Watanabe, Y.

    2011-01-01

    We report the first observational search for tau neutrinos (ν τ ) from gamma-ray bursts (GRBs) using one of the Ashra light collectors. The Earth-skimming ν τ technique of imaging Cherenkov τ showers was applied as a detection method. We set stringent upper limits on the ν τ fluence in PeV-EeV region for 3780 s (between 2.83 and 1.78 hr before) and another 3780 s (between 21.2 and 22.2 hr after) surrounding GRB081203A triggered by the Swift satellite. This first search for PeV-EeV ν τ complements other experiments in energy range and methodology, and suggests the prologue of 'multi-particle astronomy' with a precise determination of time and location.

  3. Higgs scalar in the grand desert with observable proton lifetime in SU(5) and small neutrino masses in SO(10)

    International Nuclear Information System (INIS)

    Kynshi, M.L.; Parida, M.K.

    1993-01-01

    We find that the presence of a real scalar in the grand desert transforming as ζ(3,0,8) under SU(2) L xU(1) Y xSU(3) C ensures the agreement of the GUT predictions with the data from CERN LEP and proton lifetime (τ p ). The mass of ζ is predicted to be close to the Peccei-Quinn symmetry-breaking scale. The computation of the threshold effects in SU(5) with Higgs representations 24, 5, and 75 shows that the maximum allowed τ p for reasonable superheavy Higgs boson masses is accessible to experimental tests at low energies. The additional predictions in SO(10) are small neutrino masses compatible with solutions to the solar-neutrino problem and the dark matter of the Universe

  4. 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.

  5. Los Alamos Science, Number 25 -- 1997: Celebrating the neutrino

    International Nuclear Information System (INIS)

    Cooper, N.G.

    1997-01-01

    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

  6. Observation of shadowing of neutrino- and antineutrino-nucleus interactions and comparison with PCAC predictions

    International Nuclear Information System (INIS)

    Allport, P.P.; Radojicic, D.; Guy, J.; Venus, W.; Cooper-Sarkar, A.M.; Aderholz, M.; Schmitz, N.; Wittek, W.; Berggren, M.; Jones, G.T.; O'Neale, S.; Varvell, K.; Marage, P.; Mobayyen, M.; Morrison, D.R.O.; Parker, M.A.; Wachsmuth, H.; Neveu, M.; Simopoulou, E.; Vayaki, A.; Apeldoorn, G. van

    1989-01-01

    Comparing the kinematical distributions of events obtained on neon and deuterium targets in similar experimental conditions reveals a reduction of the neutrino and antineutrino charged current cross section per nucleon in neon at low Q 2 . The effect, interpreted as due to geometric shadowing of the weak propagator in interactions of neutrinos and antineutrinos with nuclei, agrees well with predictions derived from PCAC. (orig.)

  7. Observation of shadowing of neutrino- and antineutrino-nucleus interactions and comparison with PCAC predictions

    Science.gov (United States)

    Allport, P. P.; Erriquez, O.; Guy, J.; Venus, W.; Aderholz, M.; Berggren, M.; Bullock, F. W.; Calicchio, M.; Coghen, T.; Cooper-Sarkar, A. M.; Jones, G. T.; Marage, P.; Mobayyen, M.; Morrison, D. R. O.; Neveu, M.; Parker, M. A.; Radojicic, D.; Sansum, R. A.; Saitta, B.; Schmitz, N.; Simopoulou, E.; O'neale, S.; Van Apeldoorn, G.; Varvell, K.; Vayaki, A.; Wachsmuth, H.; Wittek, W.; BEBC WA59 Collaboration

    1989-12-01

    Comparing the kinematical distributions of events obtained on neon and deuterium targets in similar experimental conditions reveals a reduction of the neutrino and antineutrino charged current cross section per nucleon in neon at low Q2. The effect, interpreted as due to geometric shadowing of the weak propagator in interactions of neutrinos and antineutrinos with nuclei, agrees well with predictions derived from PCAC.

  8. FLUORINE IN THE SOLAR NEIGHBORHOOD: NO EVIDENCE FOR THE NEUTRINO PROCESS

    Energy Technology Data Exchange (ETDEWEB)

    Jönsson, H.; Ryde, N. [Lund Observatory, Department of Astronomy and Theoretical Physics, Lund University, Box 43, SE-22100 Lund (Sweden); Spitoni, E.; Matteucci, F. [Dipartimento di Fisica, Sezione di Astronomia, Università di Trieste, via G.B. Tiepolo 11, I-34131, Trieste (Italy); Cunha, K. [Observatório Nacional, Rua General José Cristino, 77, 20921-400 São Cristóvão, Rio de Janeiro, RJ (Brazil); Smith, V.; Hinkle, K. [National Optical Astronomy Observatory, 950 North Cherry Avenue, Tucson, AZ 85719 (United States); Schultheis, M., E-mail: henrikj@astro.lu.se [Observatoire de la Cote d’Azur, Boulevard de l’Observatoire, B.P. 4229, F-06304 NICE Cedex 4 (France)

    2017-01-20

    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 μ m 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.

  9. FLUORINE IN THE SOLAR NEIGHBORHOOD: NO EVIDENCE FOR THE NEUTRINO PROCESS

    International Nuclear Information System (INIS)

    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 μ m 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.

  10. Recent Ultra High Energy neutrino bounds and multimessenger observations with the Pierre Auger Observatory

    Science.gov (United States)

    Zas, Enrique

    2018-01-01

    The overall picture of the highest energy particles produced in the Universe is changing because of measurements made with the Pierre Auger Observatory. Composition studies of cosmic rays point towards an unexpected mixed composition of intermediate mass nuclei, more isotropic than anticipated, which is reshaping the future of the field and underlining the priority to understand composition at the highest energies. The Observatory is competitive in the search for neutrinos of all flavors above about 100 PeV by looking for very inclined showers produced deep in the atmosphere by neutrinos interacting either in the atmosphere or in the Earth's crust. It covers a large field of view between -85° and 60° declination in equatorial coordinates. Neutrinos are expected because of the existence of ultra high energy cosmic rays. They provide valuable complementary information, their fluxes being sensitive to the primary cosmic ray masses and their directions reflecting the source positions. We report the results of the neutrino search providing competitive bounds to neutrino production and strong constraints to a number of production models including cosmogenic neutrinos due to ultra high energy protons. We also report on two recent contributions of the Observatory to multimessenger studies by searching for correlations of neutrinos both with cosmic rays and with gravitational waves. The correlations of the directions of the highest energy astrophysical neutrinos discovered with IceCube with the highest energy cosmic rays detected with the Auger Observatory and the Telescope Array revealed an excess that is not statistically significant and is being monitored. The targeted search for neutrinos correlated with the discovery of the gravitational wave events GW150914 and GW151226 with advanced LIGO has led to the first bounds on the energy emitted by black hole mergers in Ultra-High Energy Neutrinos.

  11. Recent Ultra High Energy neutrino bounds and multimessenger observations with the Pierre Auger Observatory

    Directory of Open Access Journals (Sweden)

    Zas Enrique

    2017-01-01

    Full Text Available The overall picture of the highest energy particles produced in the Universe is changing because of measurements made with the Pierre Auger Observatory. Composition studies of cosmic rays point towards an unexpected mixed composition of intermediate mass nuclei, more isotropic than anticipated, which is reshaping the future of the field and underlining the priority to understand composition at the highest energies. The Observatory is competitive in the search for neutrinos of all flavors above about 100 PeV by looking for very inclined showers produced deep in the atmosphere by neutrinos interacting either in the atmosphere or in the Earth’s crust. It covers a large field of view between −85◦ and 60◦ declination in equatorial coordinates. Neutrinos are expected because of the existence of ultra high energy cosmic rays. They provide valuable complementary information, their fluxes being sensitive to the primary cosmic ray masses and their directions reflecting the source positions. We report the results of the neutrino search providing competitive bounds to neutrino production and strong constraints to a number of production models including cosmogenic neutrinos due to ultra high energy protons. We also report on two recent contributions of the Observatory to multimessenger studies by searching for correlations of neutrinos both with cosmic rays and with gravitational waves. The correlations of the directions of the highest energy astrophysical neutrinos discovered with IceCube with the highest energy cosmic rays detected with the Auger Observatory and the Telescope Array revealed an excess that is not statistically significant and is being monitored. The targeted search for neutrinos correlated with the discovery of the gravitational wave events GW150914 and GW151226 with advanced LIGO has led to the first bounds on the energy emitted by black hole mergers in Ultra-High Energy Neutrinos.

  12. The Final Results from the Sudbury Neutrino Observatory

    CERN Multimedia

    CERN. Geneva

    2010-01-01

    The Sudbury Neutrino Observatory (SNO) was a water Cherenkov detector dedicated to investigate elementary particles called neutrinos. It successfully took data between 1999 and 2006. The detector was unique in its use of heavy water as a detection medium, permitting it to make a solar model-independent test of solar neutrino mixing. In fact, SNO conclusively showed that solar neutrinos oscillate on their way from the core of the Sun to the Earth. This groundbreaking observation was made during three independent phases of the experiment. Even if data taking ended, SNO is still in a mode of precise determination of the solar neutrino oscillation parameters because all along SNO had developed several methods to tell charged-current events apart from neutral-current events. This ability is crucial for the final and ultimate data analysis of all the phases. The physics reach of a combined three-phase solar analysis will be reviewed together with results and subtleties about solar neutrino physics.

  13. Recent developments in neutrino physics

    International Nuclear Information System (INIS)

    Garvey, G.T.

    1991-01-01

    I shall attempt to summarize recent developments in the experimental situation in neutrino physics. The paper will deal with recent results, drawing on either published work or research that has been presented in preprint form, as there is an adequate supply of interesting and controversial data restricting oneself to these generally more reliable sources. The discussion of the theoretical implication of these experimental results will be presented in the following paper by Boris Kayser. The topics to be covered in this presentation are: direct measurements of bar ν e mass via beta endpoint studies; status of solar neutrino observations; status of ''17-keV neutrino'' reports; and the use of νp elastic scattering to determine the ''strange quark'' content of the proton. 2 refs., 15 figs., 9 tabs

  14. Recent developments in neutrino physics

    Energy Technology Data Exchange (ETDEWEB)

    Garvey, G.T.

    1991-01-01

    I shall attempt to summarize recent developments in the experimental situation in neutrino physics. The paper will deal with recent results, drawing on either published work or research that has been presented in preprint form, as there is an adequate supply of interesting and controversial data restricting oneself to these generally more reliable sources. The discussion of the theoretical implication of these experimental results will be presented in the following paper by Boris Kayser. The topics to be covered in this presentation are: direct measurements of {bar {nu}}{sub e} mass via beta endpoint studies; status of solar neutrino observations; status of 17-keV neutrino'' reports; and the use of {nu}p elastic scattering to determine the strange quark'' content of the proton. 2 refs., 15 figs., 9 tabs.

  15. Proposed solar neutrino experiment using 81Br(nu,e-)81Kr

    International Nuclear Information System (INIS)

    Hurst, G.S.; Chen, C.H.; Kramer, S.D.; Allman, S.L.

    1984-12-01

    It has now been shown that it is feasible to measure the 7 Be neutrino source in the sun by using the reaction 81 Br(nu,e - ) 81 Kr in a radiochemical experiment. Such an experiment would be quite similar to the Davis, Cleveland, and Rowley method for measuring the 8 B neutrino using 37 Cl(nu,e - ) 37 Ar except that the resonance ionization spectroscopy (RIS) method (instead of decay counting) would be employed to count the 2 x 10 5 -yr 81 Kr atoms

  16. Solar Coronal Jets: Observations, Theory, and Modeling

    Science.gov (United States)

    Raouafi, N. E.; Patsourakos, S.; Pariat, E.; Young, P. R.; Sterling, A.; Savcheva, A.; Shimojo, M.; Moreno-Insertis, F.; Devore, C. R.; Archontis, V.; hide

    2016-01-01

    Chromospheric and coronal jets represent important manifestations of ubiquitous solar transients, which may be the source of signicant mass and energy input to the upper solar atmosphere and the solar wind. While the energy involved in a jet-like event is smaller than that of nominal solar ares and Coronal Mass Ejections (CMEs), jets share many common properties with these major phenomena, in particular, the explosive magnetically driven dynamics. Studies of jets could, therefore, provide critical insight for understanding the larger, more complex drivers of the solar activity. On the other side of the size-spectrum, the study of jets could also supply important clues on the physics of transients closeor at the limit of the current spatial resolution such as spicules. Furthermore, jet phenomena may hint to basic process for heating the corona and accelerating the solar wind; consequently their study gives us the opportunity to attack a broadrange of solar-heliospheric problems.

  17. Matter effects in neutrino oscillations

    International Nuclear Information System (INIS)

    Dass, G.V.

    1989-01-01

    After a review of the relevant aspects of neutrino oscillations for propagation in vacuum and in material media, this paper discuss the Mikheyev-Smirnov-Wolfenstein mechanism and its application to a solution of the solar neutrino puzzle. The elementary level of the talk is suitable to people not working in neutrino physics

  18. Lyman continuum observations of solar flares

    Science.gov (United States)

    Machado, M. E.; Noyes, R. W.

    1978-01-01

    A study is made of Lyman continuum observations of solar flares, using data obtained by the EUV spectroheliometer on the Apollo Telescope Mount. It is found that there are two main types of flare regions: an overall 'mean' flare coincident with the H-alpha flare region, and transient Lyman continuum kernels which can be identified with the H-alpha and X-ray kernels observed by other authors. It is found that the ground level hydrogen population in flares is closer to LTE than in the quiet sun and active regions, and that the level of Lyman continuum formation is lowered in the atmosphere from a mass column density .000005 g/sq cm in the quiet sun to .0003 g/sq cm in the mean flare, and to .001 g/sq cm in kernels. From these results the amount of chromospheric material 'evaporated' into the high temperature region is derived, which is found to be approximately 10 to the 15th g, in agreement with observations of X-ray emission measures.

  19. Two enigmas of stellar evolution: the solar neutrinos and 1987 a supernova

    International Nuclear Information System (INIS)

    Cahen, S.

    1987-01-01

    Solar models have been compared, using more recent opacity tables. Parameters to enter have been reviewed (thermonuclear reaction rate and element abundance) and opacity coefficient has been corrected. Incertitude influence of parameters on model results has been estimated. Helium initial abundance deduced from our model is coherent with observation and other calculated values. Causes of differences between some models are elucidated. For 1987a supernova, a semi-analytical model of light curve is presented. Light curve of supernovae whose progenitor is a massive star with a low initial radius. Electron recombination can explain almost the whole light emission [fr

  20. COHERENT enlightenment of the neutrino dark side

    Science.gov (United States)

    Coloma, Pilar; Gonzalez-Garcia, M. C.; Maltoni, Michele; Schwetz, Thomas

    2017-12-01

    In the presence of nonstandard neutrino interactions (NSI), oscillation data are affected by a degeneracy which allows the solar mixing angle to be in the second octant (also known as the dark side) and implies a sign flip of the atmospheric mass-squared difference. This leads to an ambiguity in the determination of the ordering of neutrino masses, one of the main goals of the current and future experimental neutrino program. We show that the recent observation of coherent neutrino-nucleus scattering by the COHERENT experiment, in combination with global oscillation data, excludes the NSI degeneracy at the 3.1 σ (3.6 σ ) C.L. for NSI with up (down) quarks.

  1. Neutrino and dark radiation properties in light of recent CMB observations

    Science.gov (United States)

    Archidiacono, Maria; Giusarma, Elena; Melchiorri, Alessandro; Mena, Olga

    2013-05-01

    Recent cosmic microwave background measurements at high multipoles from the South Pole Telescope and from the Atacama Cosmology Telescope seem to disagree in their conclusions for the neutrino and dark radiation properties. In this paper we set new bounds on the dark radiation and neutrino properties in different cosmological scenarios combining the ACT and SPT data with the nine-year data release of the Wilkinson Microwave Anisotropy Probe (WMAP-9), baryon acoustic oscillation data, Hubble Telescope measurements of the Hubble constant, and supernovae Ia luminosity distance data. In the standard three massive neutrino case, the two high multipole probes give similar results if baryon acoustic oscillation data are removed from the analyses and Hubble Telescope measurements are also exploited. A similar result is obtained within a standard cosmology with Neff massless neutrinos, although in this case the agreement between these two measurements is also improved when considering simultaneously baryon acoustic oscillation data and Hubble Space Telescope measurements. In the Neff massive neutrino case the two high multipole probes give very different results regardless of the external data sets used in the combined analyses. When considering extended cosmological scenarios with a dark energy equation of state or with a running of the scalar spectral index, the evidence for neutrino masses found for the South Pole Telescope in the three neutrino scenario disappears for all the data combinations explored here. Again, adding Hubble Telescope data seems to improve the agreement between the two high multipole cosmic microwave background measurements considered here. In the case in which a dark radiation background with unknown clustering properties is also considered, SPT data seem to exclude the standard value for the dark radiation viscosity cvis2=1/3 at the 2σ C.L., finding evidence for massive neutrinos only when combining SPT data with baryon acoustic oscillation

  2. Observational Investigation of Solar Interior and Atmosphere

    Science.gov (United States)

    Kuhn, Jeffrey R.

    2003-01-01

    The Imaging Vector Magnetograph (IVM) has been modified to make it easier to observe at more than one spectral line. The cell holding the blocking filter has been replaced by a four-position filter wheel, so that changing to a different line is a matter of a few minutes rather than the several hours it used to take to disassemble the cell and install a new filter. Three new filters have been obtained, for Na 1589.6 nm, Fe 1630.25 nm, and H 1656.3 nm. The new filters have better bandpass profiles than the ones they replaced: somewhat wider, with flatter tops and steeper wings. This results in a reduction of parasitic light coming from adjacent Fabry-Perot orders, from seven percent to about two percent, and flattens the apparent continuum. The Mees CCD Imaging Spectrograph (MCCD) was upgraded under this grant, with a new control computer and data system. The camera was replaced with a faster, larger-format frame-transfer camera. Final integration of the upgrades is not yet complete, but tests indicate that the system cadence will be improved by a factor of five to ten, while increasing the spatial coverage by a factor of two (depending on observation options). Synoptic observations with the IVM and MCCD continue to be conducted daily, to the extent permitted by the fact that we have a single observer responsible for the observations. The older Haleakala Stokes Polarimeter is also used to make a daily vector magnetogram, normally of the region selected by the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) duty scientists. This instrument, however, is showing its age to the extent that its maintenance is becoming something of a challenge. We also run a white light full-disk imager and a video H alpha prominence camera, continuously during times of observations. Of particular interest, we obtained rapid-cadence observations of the 2003 July 15 white light flare with both the IVM and MCCD. The vector magnetograms show no obvious difference between the

  3. Neutrino oscillations: present status and outlook

    International Nuclear Information System (INIS)

    Schwetz, T.

    2005-01-01

    In this talk the present status of neutrino oscillations is reviewed, based on a global analysis of world neutrino oscillation data from solar, atmospheric, reactor, and accelerator neutrino experiments. Furthermore, I discuss the expected improvements in the determination of neutrino parameters by future oscillation experiments within a timescale of 10 years. (author)

  4. Direct observations of low-energy solar electrons associated with a type 3 solar radio burst

    Science.gov (United States)

    Frank, L. A.; Gurnett, D. A.

    1972-01-01

    On 6 April 1971 a solar X-ray flare and a type 3 solar radio noise burst were observed with instrumentation on the eccentric-orbiting satellite IMP 6. The type 3 solar radio noise burst was detected down to a frequency of 31 kHz. A highly anisotropic packet of low-energy solar electron intensities arrived at the satellite approximately 6000 seconds after the onset of the solar flare. This packet of solar electron intensities was observed for 4200 seconds. Maximum differential intensities of the solar electrons were in the energy range of one to several keV. The frequency drift rate of the type 3 radio noise at frequencies below 178 kHz also indicated an average particle speed corresponding to that of a 3-keV electron. The simultaneous observations of these solar electron intensities and of the type 3 solar radio burst are presented, and their interrelationships are explored.

  5. SOLAR-ISS: A new reference spectrum based on SOLAR/SOLSPEC observations

    Science.gov (United States)

    Meftah, M.; Damé, L.; Bolsée, D.; Hauchecorne, A.; Pereira, N.; Sluse, D.; Cessateur, G.; Irbah, A.; Bureau, J.; Weber, M.; Bramstedt, K.; Hilbig, T.; Thiéblemont, R.; Marchand, M.; Lefèvre, F.; Sarkissian, A.; Bekki, S.

    2018-03-01

    Context. Since April 5, 2008 and up to February 15, 2017, the SOLar SPECtrometer (SOLSPEC) instrument of the SOLAR payload on board the International Space Station (ISS) has performed accurate measurements of solar spectral irradiance (SSI) from the middle ultraviolet to the infrared (165 to 3088 nm). These measurements are of primary importance for a better understanding of solar physics and the impact of solar variability on climate. In particular, a new reference solar spectrum (SOLAR-ISS) is established in April 2008 during the solar minima of cycles 23-24 thanks to revised engineering corrections, improved calibrations, and advanced procedures to account for thermal and aging corrections of the SOLAR/SOLSPEC instrument. Aims: The main objective of this article is to present a new high-resolution solar spectrum with a mean absolute uncertainty of 1.26% at 1σ from 165 to 3000 nm. This solar spectrum is based on solar observations of the SOLAR/SOLSPEC space-based instrument. Methods: The SOLAR/SOLSPEC instrument consists of three separate double monochromators that use concave holographic gratings to cover the middle ultraviolet (UV), visible (VIS), and infrared (IR) domains. Our best ultraviolet, visible, and infrared spectra are merged into a single absolute solar spectrum covering the 165-3000 nm domain. The resulting solar spectrum has a spectral resolution varying between 0.6 and 9.5 nm in the 165-3000 nm wavelength range. We build a new solar reference spectrum (SOLAR-ISS) by constraining existing high-resolution spectra to SOLAR/SOLSPEC observed spectrum. For that purpose, we account for the difference of resolution between the two spectra using the SOLAR/SOLSPEC instrumental slit functions. Results: Using SOLAR/SOLSPEC data, a new solar spectrum covering the 165-3000 nm wavelength range is built and is representative of the 2008 solar minimum. It has a resolution better than 0.1 nm below 1000 nm and 1 nm in the 1000-3000 nm wavelength range. The new

  6. Research and development of a helium-4 based solar neutrino detector: Progress report for period May 1, 1988--April 30, 1989

    International Nuclear Information System (INIS)

    Lanou, R.E.; Maris, H.J.; Seidel, G.M.

    1988-12-01

    This research project is designed to develop and test a new technique for detecting neutrinos using liquid 4 He in the superfluid state. Following the test results it should be possible to design a practical detector leading to the ultimate goal of detecting low energy solar neutrinos. The project was initiated on May of this year and these first seven months have been devoted to the design and construction of apparatus to carry out these tests. Construction is continuing and is described in this report

  7. Solar flare loops observations and interpretations

    CERN Document Server

    Huang, Guangli; Ji, Haisheng; Ning, Zongjun

    2018-01-01

    This book provides results of analysis of typical solar events, statistical analysis, the diagnostics of energetic electrons and magnetic field, as well as the global behavior of solar flaring loops such as their contraction and expansion. It pays particular attention to analyzing solar flare loops with microwave, hard X-ray, optical and EUV emissions, as well as the theories of their radiation, and electron acceleration/transport. The results concerning influence of the pitch-angle anisotropy of non-thermal electrons on their microwave and hard X-ray emissions, new spectral behaviors in X-ray and microwave bands, and results related to the contraction of flaring loops, are widely discussed in the literature of solar physics. The book is useful for graduate students and researchers in solar and space physics.

  8. Neutrino Physics

    CERN Multimedia

    CERN. Geneva; Dydak, Friedrich

    2001-01-01

    Starting from a review of theoretical concepts and experimental results in the early years of neutrino physics after Pauli's 1930 letter, today's double role of the neutrino as a cornerstone of the Standard Model and as a promising probe of physics beyond the Standard Model will be discussed. Topics comprise: - Conventional neutrino beams - Neutrinos as probes of the nucleon structure - Neutrinos from the universe - Dirac or Majorana neutrinos - Neutrino oscillations - MNS matrix - CP violation in the lepton sector - Neutrino factory.

  9. Neutrino Physics

    CERN Multimedia

    CERN. Geneva. Audiovisual Unit

    2002-01-01

    Starting from a review of theoretical concepts and experimental results in the early years of neutrino physics after Pauli's 1930 letter, today's double role of the neutrino as a cornerstone of the Standard Model and as a promising probe of physics beyond the Standard Model will be discussed. Topics comprise: - Conventional neutrino beams - Neutrinos as probes of the nucleon structure - Neutrinos from the universe - Dirac or Majorana neutrinos - Neutrino oscillations - MNS matrix - CP violation in the lepton sector - Neutrino factory.

  10. Solar constraints

    International Nuclear Information System (INIS)

    Provost, J.

    1984-01-01

    Accurate tests of the theory of stellar structure and evolution are available from the Sun's observations. The solar constraints are reviewed, with a special attention to the recent progress in observing global solar oscillations. Each constraint is sensitive to a given region of the Sun. The present solar models (standard, low Z, mixed) are discussed with respect to neutrino flux, low and high degree five-minute oscillations and low degree internal gravity modes. It appears that actually there do not exist solar models able to fully account for all the observed quantities. (Auth.)

  11. Design and testing of the measuring equipment for the detection of 71Ge and 69Ge within the gallium-solar-neutrino experiment

    International Nuclear Information System (INIS)

    Huebner, M.

    1980-01-01

    A low level measuring system has been developed for the Ga-solar-neutrino experiment, to detect the reaction 71 Ga (νsub(e),e - ) 71 Ge by the decay 71 Ge (Tsub(1/2) = 11. 4 d, 100% electron capture). An estimate based on the solar standard model gives 15 71 Ge atoms produced by solar neutrinos (pp and pep). As a monitor for background reactions in the target, the detectability of the 69 Ga (p,n) 69 Ge reaction by the decay 69 Ge (Tsub(1/2) = 39 h, 37% β + -decay, 63% electron capture) has been considered. To test the system, the detectors are mounted in a low level laboratory lead box. (orig./WB) [de

  12. Three Dirac neutrinos

    International Nuclear Information System (INIS)

    Joshipura, A.S.; Rindani, S.D.

    1991-01-01

    The consequences of imposing an exact L e +L τ -L μ symmetry on a 6x6 matrix describing neutrino masses are discussed. The presence of right-handed neutrinos avoids the need of introducing any SU(2) Higgs triplet. Hence the conflict with the CERN LEP data on the Z width found in earlier models with L e +L τ -L μ symmetry is avoided. The L e +L τ -L μ symmetry provides an interesting realization of a recent proposal of Glashow to accommodate the 17-keV Dirac neutrino in the SU(2)xU(1) theory. All the neutrinos in this model are Dirac particles. The solar-neutrino problem can be solved in an extension of the model which generates a large (∼10 -11 μ B ) magnetic moment for the electron neutrino

  13. 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.

  14. Observed ices in the Solar System

    Science.gov (United States)

    Clark, Roger N.; Grundy, Will; Carlson, Robert R.; Noll, Keith; Gudipati, Murthy; Castillo-Rogez, Julie C.

    2013-01-01

    Ices have been detected and mapped on the Earth and all planets and/or their satellites further from the sun. Water ice is the most common frozen volatile observed and is also unambiguously detected or inferred in every planet and/or their moon(s) except Venus. Carbon dioxide is also extensively found in all systems beyond the Earth except Pluto although it sometimes appears to be trapped rather than as an ice on some objects. The largest deposits of carbon dioxide ice is on Mars. Sulfur dioxide ice is found in the Jupiter system. Nitrogen and methane ices are common beyond the Uranian system. Saturn’s moon Titan probably has the most complex active chemistry involving ices, with benzene (C6H6) and many tentative or inferred compounds including ices of Cyanoacetylene (HC3N), Toluene (C7H8), Cyanogen (C2N2), Acetonitrile (CH3CN), H2O, CO2, and NH3. Confirming compounds on Titan is hampered by its thick smoggy atmosphere. Ammonia was predicted on many icy moons but is notably absent among the definitively detected ices with the possible exception of Enceladus. Comets, storehouses of many compounds that could exist as ices in their nuclei, have only had small amounts of water ice definitively detected on their surfaces. Only one asteroid has had a direct detection of surface water ice, although its presence can be inferred in others. This chapter reviews some of the properties of ices that lead to their detection, and surveys the ices that have been observed on solid surfaces throughout the Solar System.

  15. Study of neutrino production in the Cannonball model of Gamma ray bursts: possibility of observation of these neutrinos with the Antares neutrinos telescope, and study of the optical background recorded with the prototype sector line; Etude de la production de neutrinos associes aux Sursauts Gamma dans le modele du Boulet de canon: possibilite d'observation de ces neutrinos par le detecteur ANTARES, et etude du bruit de fond optique enregistre par le prototype d'un secteur de ligne

    Energy Technology Data Exchange (ETDEWEB)

    Ferry, S

    2004-09-15

    ANTARES is a future neutrino telescope which will be build at 40 km off the french coast (Toulon), at a 2500 m depth. The interaction of a neutrino with matter produces a muon which emits Cerenkov light while propagating in water. This light is detected with 900 photomultipliers distributed over 12 lines. Gamma ray bursts (GRB) are violent cosmological phenomenon observed once per day. In the Cannonball Model, bursts are produced by the interaction of a jet made of cannonballs (CB) with a supernova remnant (SNR). Forward shocks propagate in the SNR, reverse ones in the CB and neutrinos are produced at the shock fronts. An estimation of the neutrino production is given and is studied over a large parameter range. For a typical GRB, 0.002 to 0.3 v{sub {mu}}, cm{sup -2} can be produced. Depending on the viewing angle, ANTARES could detect 1 to 10 v{sub {mu}} per year in correlation with GRBs. The ambient optical background has been recorded by the ANTARES prototype sector line. The analysis is about the background influence on the detector performance and about the organisms activity which produces it. For example, it appears a 17.6 to 20.4 h periodicity which is compatible with the liquid masses movement imposed by the Coriolis force at the ANTARES latitude. (author)

  16. Ionospheric Caustics in Solar Radio Observations

    Science.gov (United States)

    Koval, A.; Chen, Y.; Stanislavsky, A.

    2016-12-01

    The Earth ionosphere possesses by natural focusing and defocusing effects on radio waves due to presence of variable ionospheric irregularities which could act like convergent and divergent lenses on incident radiation. In particular, the focusing of emission from the Sun was firstly detected on the Nançay Decameter Array dynamic spectra in the 1980s. On time-frequency spectrograms the intensity variations form specific structures different from well-known solar radio bursts and clearly distinguishing on a background of solar radiation. Such structures have been identified as ionospheric caustics (ICs) and considered to be the result of radio waves refraction on medium scale travelling ionospheric disturbances (MSTIDs). Although nowadays the ICs are registered by different radio observatories due to augmentation of low-frequency radio telescopes, the most recent papers devoted to ICs in solar radio records date back to the 1980s. In this study, we revisit the ICs issue with some new results by conducting a statistical analysis of occurrence rate of ICs in solar dynamic spectra in meter-decameter wavelength range for long continuous period (15 years). The seasonal variations in ICs appearance have been found for the first time. Besides, we report the possible solar cycle dependence of ICs emergence. The radio waves propagation in the ionosphere comprising MSTIDs will be considered. The present research renews the subject of ICs in the low-frequency solar radio astronomy after about 35-year letup.

  17. Low-energy neutrino measurements

    Indian Academy of Sciences (India)

    2012-10-05

    Oct 5, 2012 ... Abstract. Low-energy solar neutrino detection plays a fundamental role in ... the experimental point of view, there are multiple ways to shed light among the different .... compared to the two metallicity expectations [16]. ..... from the Earth; solar neutrinos; indirect dark matter searches) and GeV physics (pro-.

  18. Status of Heavy Neutrino Experiments

    CERN Document Server

    Wynne, Benjamin; The ATLAS collaboration

    2017-01-01

    The observation of neutrino oscillations raises the possibility that there exist additional, undiscovered high-mass neutrinos, giving mass to Standard Model neutrinos via the seesaw mechanism. By pushing the collider energy frontier at the LHC, the possibility arises that these heavy neutrinos may be produced and identified. We summarise the latest LHC results of searches for heavy neutrinos in a variety of final states.

  19. 152nd International School of Physics "Enrico Fermi": Neutrino Physics

    CERN Document Server

    Declais, Y; Strolin, P; Zanotti, L; Società Italiana di Fisica. Bologna. Scuola internazionale di fisica "Enrico Fermi"; International School of Physics "Enrico Fermi": Neutrino Physics; Scuola Internazionale di Fisica "Enrico Fermi" : Phisica dei neutrini

    2003-01-01

    Neutrino physics contributed in an fundamental way to the progress of science, opening important windows of knowledge in elementary particle physics, as well in astrophysics and cosmology. Substantial experimental efforts are presently dedicated to improve our knowledge on neutrino properties as, in fact, we don't know yet some of the basic ones. Although very significant steps forward have been done, neutrino masses and mixings still remain largely unknown and constitute an important field for future research. Are neutrinos Majorana or Dirac particles? Have they a magnetic moment? Historically, studies on weak processes and, therefore, on neutrino physics, provided first the Fermi theory of weak interactions and then the V-A theory. Finally, the observation of weak neutral currents provided the first experimental evidence for unification of weak and electromagnetic interactions by the so called "Standard Model' of elementary particles. In addition to the results obtained from the measurement of the solar neu...

  20. Sudbury Neutrino Observatory

    International Nuclear Information System (INIS)

    Beier, E.W.

    1992-03-01

    This document is a technical progress report on work performed at the University of Pennsylvania during the current year on the Sudbury Neutrino Observatory project. The motivation for the experiment is the measurement of neutrinos emitted by the sun. The Sudbury Neutrino Observatory (SNO) is a second generation dedicated solar neutrino experiment which will extend the results of our work with the Kamiokande II detector by measuring three reactions of neutrinos rather than the single reaction measured by the Kamiokande experiment. The collaborative project includes physicists from Canada, the United Kingdom, and the United States. Full funding for the construction of this facility was obtained in January 1990, and its construction is estimated to take five years. The motivation for the SNO experiment is to study the fundamental properties of neutrinos, in particular the mass and mixing parameters, which remain undetermined after decades of experiments in neutrino physics utilizing accelerators and reactors as sources of neutrinos. To continue the study of neutrino properties it is necessary to use the sun as a neutrino source. The long distance to the sun makes the search for neutrino mass sensitive to much smaller mass than can be studied with terrestrial sources. Furthermore, the matter density in the sun is sufficiently large to enhance the effects of small mixing between electron neutrinos and mu or tau neutrinos. This experiment, when combined with the results of the radiochemical 37 Cl and 71 Ga experiments and the Kamiokande II experiment, should extend our knowledge of these fundamental particles, and as a byproduct, improve our understanding of energy generation in the sun

  1. Neutrino Interactions

    International Nuclear Information System (INIS)

    Kamyshkov, Yuri; Handler, Thomas

    2016-01-01

    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 θ_1_3 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

  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. Experimental Neutrino Physics and Astrophysics with the IMB-3 Detector

    Science.gov (United States)

    Casper, David William

    1990-01-01

    Description of the universe on the smallest (elementary particle physics) and largest (cosmology) scales has become dependent on the properties of the most weakly interacting fundamental particle known, the neutrino. The IMB experiment, designed to study nucleon decay, is also the world's largest detector of neutrinos. The experiment uses 6800 tons (3300 tons fiducial) of water as both target and detecting medium. Relativistic charges particles traversing the water radiate Cerenkov light. The distinctive ring patterns are imaged by 2048 light collectors (each a photo-multiplier tube coupled with a wavelength-shifting plate) distributed over the surfaces of the tank. This dissertation describes the IMB-3 detector, a four-fold increase in sensitivity over the original apparatus. Neutrino interactions of both atmospheric and extragalactic origin were collected during a 3.4 kiloton-year exposure. A consequence of non-zero neutrino mass could be oscillation of neutrino flavor. The energies and long flight distances of atmospheric neutrinos offer a unique opportunity to explore this possibility. To study the composition of the atmospheric neutrinos, single-ring events are classified as showering or non-showering using the geometry of the Cerenkov pattern. A simulation of neutrino interactions and a model of atmospheric neutrino production are used to predict the composition of the sample. The showering/non-showering character of an event is strongly correlated with the flavor of its neutrino parent. In the lepton momentum range p mass or "dark matter" problem result in high-energy neutrino production within the Sun. A model of dark matter capture and annihilation in the Sun predicts the resulting neutrino fluxes at Earth. No evidence of the phenomenon is observed, but for canonical values of dark matter density and velocity in the solar system, greater exposure will be required to verify or exclude the expected signal.

  4. Solar-wind minor ions: recent observations

    International Nuclear Information System (INIS)

    Bame, S.J.

    1982-01-01

    During the years following the Solar Wind Four Conference at Burghausen our knowledge of the solar wind ion composition and dynamics has grown. There have been some surprises, and our understanding of the evolution of the solar wind has been improved. Systematic studies have shown that the minor ions generally travel with a common bulk speed and have temperatures roughly proportional to their masses. It has been determined that the 3 He ++ content varies greatly; 3 He ++ / 4 He ++ ranges from as high as 10 2 values to below 2 x 10 - 4 . In some solar wind flows which can be related to energetic coronal events, the minor ions are found in unusual ionization states containing Fe 16 + as a prominent ion, showing that the states were formed at unusually high temperatures. Unexpectedly, in a few flows substantial quantities of 4 He + have been detected, sometimes with ions identifiable as O 2 + and O 3 + . Surprisingly, in some of these examples the ionization state is mixed showing that part of the plasma escaped the corona without attaining the usual million-degree temperatures while other parts were heated more nearly in the normal manner. Additionally, detailed studies of the minor ions have increased our understanding of the coronal expansion. For example, such studies have contributed to identifying near equatorial coronal streamers as the source of solar wind flows between high speed streams

  5. The Sudbury Neutrino Observatory

    International Nuclear Information System (INIS)

    Norman, E.B.; Chan, Y.D.; Garcia, A.; Lesko, K.T.; Smith, A.R.; Stokstad, R.G.; Zlimen, I.; Evans, H.C.; Ewan, G.T.; Hallin, A.; Lee, H.W.; Leslie, J.R.; MacArthur, J.D.; Mak, H.B.; McDonald, A.B.; McLatchie, W.; Robertson, B.C.; Skensved, P.; Sur, B.; Jagam, P.; Law, J.; Ollerhead, R.W.; Simpson, J.J.; Wang, J.X.; Tanner, N.W.; Jelley, N.A.; Barton, J.C.; Doucas, G.; Hooper, E.W.; Knox, A.B.; Moorhead, M.E.; Omori, M.; Trent, P.T.; Wark, D.L.

    1992-11-01

    Two experiments now in progress have reported measurements of the flux of high energy neutrinos from the Sun. Since about 1970, Davis and his co-workers have been using a 37 Cl-based detector to measure the 7 Be and 8 B solar neutrino flux and have found it to be at least a factor of three lower than that predicted by the Standard Solar Model (SSM). The Kamiokande collaborations has been taking data since 1986 using a large light-water Cerenkov detector and have confirmed that the flux is about two times lower than predicted. Recent results from the SAGE and GALLEX gallium-based detectors show that there is also a deficit of the low energy pp solar neutrinos. These discrepancies between experiment and theory could arise because of inadequacies in the theoretical models of solar energy generation or because of previously unobserved properties of neutrinos. The Sudbury Neutrino Observatory (SNO) will provide the information necessary to decide which of these solutions to the ''solar neutrino problem'' is correct

  6. Neutrino oscillations and a new Faraday effect

    International Nuclear Information System (INIS)

    Anwar Mughal, M.; Ahmed, K.

    1992-07-01

    By analogy with the classical Faraday effect for the electromagnetic waves, a Faraday effect for massive neutrinos is found to be a somewhat generic description of neutrino oscillations when the neutrinos traverse a dense medium with or without a magnetic field. We further plot the Faraday angle for the solar neutrino problem as an illustration of the fact that the Faraday effect may yield a conceptually convenient parametrization of various neutrino oscillation scenarios. (author). 8 refs, 3 figs

  7. Ancient Chinese observations of physical phenomena attending solar eclipses

    International Nuclear Information System (INIS)

    Wang, P.K.; Siscoe, G.L.

    1980-01-01

    The realization that solar activity probably undergoes changes in qualitative character on time scales greater than the 11 or 22 year cycle but short compared to the duration of recorded history gives renewed importance to historical documents describing the state of solar activity. Modern eclipse observation reveal the presence of solar acitivity through the appearance of coronal structures and prominences. It has been widely remarked that eclipse records prior to the 18th century are uniformly silent on these conspicuous solar eclipse features, raising the possibility, however unlikely, that a change in solar activity has occurred which rendered them only recently noticeable. We present here material from ancient Chinese sources, primarily astrological, that describe phenomena attending solar eclipses that are almost certainly coronal structures and prominences. Thus, these aspects of the present character of solar activity have apparently occurred at other times in history, if not continuously. (orig.)

  8. Mikheyev-Smirnov-Wolfenstein effect in electron-neutrino scattering experiments

    International Nuclear Information System (INIS)

    Bahcall, J.N.; Gelb, J.M.; Rosen, S.P.

    1987-01-01

    We calculate the influence of resonant neutrino scattering [the Mikheyev-Smirnov-Wolfenstein (MSW) effect] in the Sun and in the Earth on measurable quantities in solar-neutrino--electron scattering experiments. The MSW effect reduces the expected rate for 8 B-neutrino--electron scattering by a factor that ranges from --0.8 to --0.2 if resonant scattering is the correct explanation for the discrepancy between observation and calculation in the /sup 37/Cl experiment. The Earth can produce a significant diurnal effect for certain values of the neutrino mixing angle and mass difference

  9. The singular seesaw mechanism with hierarchical Dirac neutrino mass

    International Nuclear Information System (INIS)

    Chikira, Y.; Mimura, Y.

    2000-01-01

    The singular seesaw mechanism can naturally explain the atmospheric neutrino deficit by maximal oscillations between ν μ L and ν μ R . This mechanism can also induce three different scales of the neutrino mass squared differences, which can explain the neutrino deficits of three independent experiments (solar, atmospheric, and LSND) by neutrino oscillations. In this paper we show that realistic mixing angles among the neutrinos can be obtained by introducing a hierarchy in the Dirac neutrino mass. In the case where the Majorana neutrino mass matrix has rank 2, the solar neutrino deficit is explained by vacuum oscillations between ν e and ν τ . We also consider the case where the Majorana neutrino mass matrix has rank 1. In this case, the matter enhanced Mikheyev-Smirnov-Wolfenstein solar neutrino solution is preferred as the solution of the solar neutrino deficit. (orig.)

  10. Neutrinos (1/3)

    CERN Multimedia

    CERN. Geneva

    2013-01-01

    The neutrino, the lightest and most weakly interacting particle of the Standard Model has revealed itself as the messenger of very exciting news in particle physics: there is Physics Beyond the Standard Model. All this thanks to the quantum-mechanical phenomenon of flavour oscillations which is intrinsically connected to the question of neutrino mass and which has been observed in neutrinos produced in natural sources, like the Sun and the Earth's atmosphere, as well as with human made neutrino beams at accelerator and reactors. The purpose of these lectures is to overview some aspects of the phenomenology of massive neutrinos. I will present the simplest extensions for adding neutrino masses to the SM, and then I will describe the phenomenology associated with neutrino oscillations in vacuum and in matter and its present signatures.

  11. Solar radiation observation stations updated to 1979

    Energy Technology Data Exchange (ETDEWEB)

    Carter, E.A.; Cristina, J.R.; Williams, B.B.

    1979-04-01

    The type of sensing and recording equipment for 420 stations in the US are listed alphabetically by states. The stations are divided according to whether or not they are in the basic National Weather Service, NOAA, network. Reports of summarized solar radiation data are listed in an appendix. (MHR)

  12. Effects of a Deep Mixed Shell on Solar g-Modes, p-Modes, and Neutrino Flux

    Science.gov (United States)

    Wolff, Charles L.

    2009-08-01

    A mixed-shell model that reflects g-modes away from the Sun's center is developed further by calibrating its parameters and evaluating a mixing mechanism: buoyancy. The shell roughly doubles g-mode oscillation periods and would explain why there is no definitive detection of their periods. But the shell has only minor effects on most p-modes. The model provides a mechanism for causing short-term fluctuations in neutrino flux and makes plausible the correlations between this flux and solar activity levels. Relations are derived for a shell heated asymmetrically by transient increases in nuclear burning in small "hot spots." The size of these spots and the timing of a heating event are governed by sets(ell) of standing asymptotic g-modes, coupled by a maximal principle that greatly enhances their excitation and concentrates power toward the equator, assisting the detection of higher-ell sets. Signals from all sets, except one, in the range 2 energy to mix the corresponding shell in a standard solar model in Lt107 yr.

  13. Neutrino Oscillations Physics

    Science.gov (United States)

    Fogli, Gianluigi

    2005-06-01

    We review the status of the neutrino oscillations physics, with a particular emphasis on the present knowledge of the neutrino mass-mixing parameters. We consider first the νμ → ντ 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 ±1σ (and NDF = 1) as: Δm2 = (2.6 ± 0.4) × 10-3 eV2 and sin 2 2θ = 1.00{ - 0.05}{ + 0.00} . Such indications, presently dominated by SK, could be strengthened by further K2K data. Then we point out that the recent data from the Sudbury Neutrino Observatory, together with other relevant measurements from solar and reactor neutrino experiments, in particular the KamLAND data, convincingly show that the flavor transitions of solar neutrinos are affected by Mikheyev-Smirnov-Wolfenstein (MSW) effects. Finally, we perform an updated analysis of two-family active oscillations of solar and reactor neutrinos in the standard MSW case.

  14. Neutrino clouds and dark matter

    International Nuclear Information System (INIS)

    Goldman, T.; McKellar, B.H.J.; Stephenson, G.J. Jr.

    1996-01-01

    We have examined the consequences of assuming the existence of a light scalar boson, weakly coupled to neutrinos, and not coupled to any other light fermions. For a range of parameters, we find that this hypothesis leads to the development of neutrino clusters which form in the early Universe and which provide gravitational fluctuations on scales small compared to a parsec (i.e., the scale of solar systems). Under some conditions, this can produce anomalous gravitational acceleration within solar systems and lead to a vanishing of neutrino mass-squared differences, giving rise to strong neutrino oscillation effects

  15. Neutrino-Flavoured Sneutrino Dark Matter

    CERN Document Server

    March-Russell, John; McCullough, Matthew

    2010-01-01

    A simple theory of supersymmetric dark matter (DM) naturally linked to neutrino flavour physics is studied. The DM sector comprises a spectrum of mixed lhd-rhd sneutrino states where both the sneutrino flavour structure and mass splittings are determined by the associated neutrino masses and mixings. Prospects for indirect detection from solar capture are good due to a large sneutrino-nucleon cross-section afforded by the inelastic splitting (solar capture limits exclude an explanation of DAMA/LIBRA). We find parameter regions where all heavier states will have decayed, leaving only one flavour mixture of sneutrino as the candidate DM. Such regions have a unique `smoking gun' signature--sneutrino annihilation in the Sun produces a pair of neutrino mass eigenstates free from vacuum oscillations, with the potential for detection at neutrino telescopes through the observation of a hard spectrum of nu_mu and nu_tau (for a normal neutrino hierarchy). Next generation direct detection experiments can explore much of...

  16. Measurement of the efficient cross section of the reaction 7Be(p, γ)8B at low energies and implications in the problem of solar neutrinos

    International Nuclear Information System (INIS)

    Hammache, Fairouz

    1999-01-01

    The 8 B produced inside the sun through the reaction 7 Be(p,γ) 8 B is the main, and even unique, source of high energy neutrinos detected in most solar neutrino detection experiments, except with Gallex and Sage. These experiments have all measured a neutrinos flux lower than the one predicted by solar models. Several explanations have been proposed to explain this deficit, but all require a precise knowledge of the efficient cross-section of the reaction 7 Be(p,γ) 8 B, because the neutrinos flux of 8 B is directly proportional to this reaction. The direct measurement of this cross section for the solar energy is impossible because of its low value (about 1 femto-barn). In order to get round this problem, the cross sections are measured at higher energy and extrapolated to the solar energy using a theoretical energy dependence. The 6 previous experimental determinations of the efficient cross section were shared in two distinct groups with differences of about 30% which leads to an uncertainty of the same order on the high energy neutrinos flux. The re-measurement of the cross section of this reaction with a better precision is thus of prime importance. A direct measurement of the cross section in the energy range comprised between 0.35 and 1.4 MeV (cm) has been performed first. These experiments have permitted the precise measurement of each parameter involved in the determination of the cross section. Then, measurements of the cross section have been carried out with the PAPAP accelerator at 185.8, 134.7 and 111.7 keV, the lowest mass center energy never reached before. The results are in excellent agreement with those obtained at higher energies. The value obtained by extrapolation of these data for the astrophysical factor S 17 (0) is 19.21.3 EV-B, which leads to a significant reduction of the uncertainty on the high energy neutrinos flux of 8 B. (J.S.)

  17. Observing the Birth of Supermassive Black Holes with the Planned ICECUBE Neutrino Detector

    International Nuclear Information System (INIS)

    Shi, X.; Fuller, G.M.; Halzen, F.

    1998-01-01

    It has been suggested that the supermassive black holes, at the centers of galaxies and quasars, may initially form in single collapses of relativistic star clusters or supermassive stars built up during the evolution of dense star clusters. We show that it may be possible for ICECUBE (a planned 1km 3 neutrino detector in Antarctica) to detect the neutrino bursts associated with those collapses at redshift z approx-lt 0.2 with a rate of ∼ 0.1 - 1 burst per year. Such detections could give new insights into the formation of structure in the Universe, especially when correlated with gravitational wave signatures or even gamma-ray bursts. copyright 1998 The American Physical Society

  18. Observation of solar wind with radio-star scintillation

    International Nuclear Information System (INIS)

    Watanabe, Takashi

    1974-01-01

    Large solar flares occurred in groups in early August 1972, and many interesting phenomena were observed. The solar wind condition during this period, obtained by scintillation observation, is reviewed. The velocity of solar wind has been determined from the observation of interplanetary space scintillation at Toyokawa, Fujigamine and Sugadaira. Four to ten radio wave sources were observed for ten minutes at each southing every day. Strong earth magnetic storm and the Forbush decrease of cosmic ray were observed during the period from August 3rd to 7th. Pioneer 9 observed a solar wind having the maximum velocity as high as 1,100 km/sec, and HEOS-II observed a solar wind having the velocity close to 2,000 km/sec. On the other hand, according to the scintillation of 3C-48 and 3C-144, the velocity of solar wind passing in the interplanetary space on the westside of the earth was only 300 to 400 km/sec. Therefore it is considered that the condition of solar wind on the east side of the earth differs from that on the west side of the earth. Pioneer 9 observed the pass of a shock wave on August 9th. With all radio wave sources, high velocity solar wind was observed and Pioneer 6 positioned on the west side of the earth also observed it. The thickness of this shock wave is at least 0.3 AU. Discussion is made on the cause for the difference between the asymmetric shock wave in the direction of south-west and symmetrical shock wave. The former may be blast wave, and the latter may be piston driven shock wave and the like. (Iwakiri, K.)

  19. Neutrino properties from cosmology

    DEFF Research Database (Denmark)

    Hannestad, S.

    2013-01-01

    In recent years precision cosmology has become an increasingly powerful probe of particle physics. Perhaps the prime example of this is the very stringent cosmological upper bound on the neutrino mass. However, other aspects of neutrino physics, such as their decoupling history and possible non......-standard interactions, can also be probed using observations of cosmic structure. Here, I review the current status of cosmological bounds on neutrino properties and discuss the potential of future observations, for example by the recently approved EUCLID mission, to precisely measure neutrino properties....

  20. Observed solar near UV variability: A contribution to variations of the solar constant

    International Nuclear Information System (INIS)

    London, J.; Pap, J.; Rottman, G.J.

    1989-01-01

    Continuous Measurements of the Solar UV have been made by an instrument on the Solar Mesosphere Explorer (SME) since October 1981. The results for the wavelength interval 200 to 300 nm show an irradiance decrease to a minimum in early 1987 and a subsequent increase to mid-April 1989. The observed UV changes during part of solar cycles 21 to 22 represent approx. 35 percent (during the decreasing phase) and 25 percent (during the increasing phase) of the observed variations of the solar constant for the same time period as the SME measurements

  1. Constraining the 7Be(p,γ)8B S-factor with the new precise 7Be solar neutrino flux from Borexino

    Science.gov (United States)

    Takács, M. P.; Bemmerer, D.; Junghans, A. R.; Zuber, K.

    2018-02-01

    Among the solar fusion reactions, the rate of the 7Be(p , γ)8B reaction is one of the most difficult to determine rates. In a number of previous experiments, its astrophysical S-factor has been measured at E = 0.1- 2.5 MeV centre-of-mass energy. However, no experimental data is available below 0.1 MeV. Thus, an extrapolation to solar energies is necessary, resulting in significant uncertainty for the extrapolated S-factor. On the other hand, the measured solar neutrino fluxes are now very precise. Therefore, the problem of the S-factor determination is turned around here: Using the measured 7Be and 8B neutrino fluxes and the Standard Solar Model, the 7Be(p , γ)8B astrophysical S-factor is determined at the solar Gamow peak. In addition, the 3He(α , γ)7Be S-factor is redetermined with a similar method.

  2. Capturing Neutrinos from a Star's Final Hours

    Science.gov (United States)

    Hensley, Kerry

    2018-04-01

    Patton (University of Washington) and collaborators first used a stellar evolution model to explore neutrino production in massive stars. They modeled the evolution of two massive stars 15 and 30 times the mass of our Sun from the onset of nuclear fusion to the moment of collapse.The authors found that in the last few hours before collapse, during which the material in the stars cores is rapidly upcycled into heavier elements, the flux from beta-process neutrinos rivals that of thermal neutrinos and even exceeds it at high energies. So now we know there are many beta-process neutrinos but can we spot them?Neutrino and antineutrino fluxes at Earth from the last 2 hours of a 30-solar-mass stars life compared to the flux from background sources. The rows represent calculations using two different neutrino mass hierarchies. Click to enlarge. [Patton et al. 2017]Observing Elusive NeutrinosFor an imminent supernova at a distance of 1 kiloparsec, the authors find that the presupernova electron neutrino flux rises above the background noise from the Sun, nuclear reactors, and radioactive decay within the Earth in the final two hours before collapse.Based on these calculations, current and future neutrino observatories should be able to detect tens of neutrinos from a supernova within 1 kiloparsec, about 30% of which would be beta-process neutrinos. As the distance to the star increases, the time and energy window within which neutrinos can be observed gradually narrows, until it closes for stars at a distance of about 30 kiloparsecs.Are there any nearby supergiants soon to go supernova so these predictions can be tested? At a distance of only 650 light-years, the red supergiant star Betelgeuse should produce detectable neutrinos when it explodes an exciting opportunity for astronomers in the far future!CitationKelly M. Patton et al 2017ApJ8516. doi:10.3847/1538-4357/aa95c4

  3. Neutrino physics

    International Nuclear Information System (INIS)

    Gil-Botella, I.

    2011-01-01

    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. (author)

  4. sin2 θ W estimate and bounds on nonstandard interactions at source and detector in the solar neutrino low-energy regime

    Science.gov (United States)

    Khan, Amir N.; McKay, Douglas W.

    2017-07-01

    We explore the implications of the Borexino experiment's real time measurements of the lowest energy part of the neutrino spectrum from the primary pp fusion process up to 0.420 MeV through the 7Be decay at 0.862 MeV to the pep reaction at 1.44 MeV. We exploit the fact that at such low energies, the large mixing angle solution to the Mikheyev-Smirnov-Wolfenstein matter effects in the sun are small for 7Be and pep and negligible for pp. Consequently, the neutrinos produced in the sun change their flavor almost entirely through vacuum oscillations during propagation from the sun's surface and through possible nonstandard interactions acting at the solar source and Borexino detector. We combine the different NSI effects at source and detector in a single framework and use the current Borexino data to bound NSI non-universal and flavor-changing parameters at energies below the reach of reactor neutrino experiments. We also study the implication of the current data for the weak-mixing angle at this "low-energy frontier" data from the Borexino experiment, where it is expected to be slightly larger than its value at the Z mass. We find sin2 θ W = 0.224 ± 0.016, the lowest energy-scale estimate to date. Looking to the future, we use projected sensitivities to solar neutrinos in next generation dedicated solar experiments and direct dark matter detection experiments and find a potential factor five improvement in determination of the weak-mixing angle and up to an order of magnitude improvement in probing the NSI parameters space.

  5. Solar System Observations with the James Webb Space Telescope

    OpenAIRE

    Norwood, James; Hammel, Heidi; Milam, Stefanie; Stansberry, John; Lunine, Jonathan; Chanover, Nancy; Hines, Dean; Sonneborn, George; Tiscareno, Matthew; Brown, Michael; Ferruit, Pierre

    2014-01-01

    The James Webb Space Telescope will enable a wealth of new scientific investigations in the near- and mid-infrared, with sensitivity and spatial/spectral resolution greatly surpassing its predecessors. In this paper, we focus upon Solar System science facilitated by JWST, discussing the most current information available concerning JWST instrument properties and observing techniques relevant to planetary science. We also present numerous example observing scenarios for a wide variety of Solar...

  6. Results from neutrino experiments

    International Nuclear Information System (INIS)

    Smirnov, A.Yu.

    1993-11-01

    Recent (first or/and the best) results from the neutrino experiments are reviewed and their implications for the theory are discussed. The sense of the experiments is the searching for neutrino masses, mixing and interactions beyond the standard model. Present laboratory experiments give upper bounds on the masses and the mixing which are at the level of predictions of the ''electroweak see-saw''. Positive indications of nonzero lepton mixing follow from studies of the solar and atmospheric neutrinos. (author). 95 refs, 11 figs

  7. Mass relation for neutrinos

    Science.gov (United States)

    Babu; Barr

    2000-08-07

    A generalization of the well-known Georgi-Jarlskog relation (m(&mgr;)/m(tau)) = 3(m(s)/m(b)) to neutrinos is found in the context of SO(10). This new relation is (m(nu(&mgr;))/m(nu(tau))) = 16(m(c)/m(t)), which is consistent with present data, assuming the Mikheyev-Smirnov-Wolfenstein solution to the solar neutrino problem.

  8. Mass Relation for Neutrinos

    International Nuclear Information System (INIS)

    Babu, K. S.; Barr, S. M.

    2000-01-01

    A generalization of the well-known Georgi-Jarlskog relation (m μ /m τ ) =3(m s /m b ) to neutrinos is found in the context of SO(10) . This new relation is (m ν μ /m ν τ )=16(m c /m t ) , which is consistent with present data, assuming the Mikheyev-Smirnov-Wolfenstein solution to the solar neutrino problem. (c) 2000 The American Physical Society

  9. Neutrinos: Heavy water detector

    International Nuclear Information System (INIS)

    Anon.

    1990-01-01

    The proponents of the Sudbury Neutrino Observatory (SNO) received a welcome Christmas present when William Winegard, Canadian Minister for Science and Technology announced the final details of the funding for this project, totalling 48 million Canadian dollars and including contributions from the US and the UK. The SNO experiment will extend significantly the study of solar neutrinos, using some 1,000 tonnes of heavy water to be installed more than two kilometres below ground in a nickel mine at Sudbury, Ontario

  10. Beta rays and neutrinos

    International Nuclear Information System (INIS)

    Adams, S.F.

    1992-01-01

    It was over 30 years between the first observation of the enigmatic process of beta decay and the first postulation of the neutrino. It took a further 26 years until the first neutrino was detected and yet another 27 until the electroweak theory was confirmed by the discovery of W and Z particles. This article traces some of the puzzles and paradoxes associated with the history of the neutrino. (author)

  11. Solar wind ion trends and signatures: STEREO PLASTIC observations approaching solar minimum

    Directory of Open Access Journals (Sweden)

    A. B. Galvin

    2009-10-01

    Full Text Available STEREO has now completed the first two years of its mission, moving from close proximity to Earth in 2006/2007 to more than 50 degrees longitudinal separation from Earth in 2009. During this time, several large-scale structures have been observed in situ. Given the prevailing solar minimum conditions, these structures have been predominantly coronal hole-associated solar wind, slow solar wind, their interfaces, and the occasional transient event. In this paper, we extend earlier solar wind composition studies into the current solar minimum using high-resolution (1-h sampling times for the charge state analysis. We examine 2-year trends for iron charge states and solar wind proton speeds, and present a case study of Carrington Rotation 2064 (December 2007 which includes minor ion (He, Fe, O kinetic and Fe composition parameters in comparison with proton and magnetic field signatures at large-scale structures observed during this interval.

  12. Development of a computer code for the calculation of stellar evolution, with applications to solar models of low neutrino flux

    International Nuclear Information System (INIS)

    Newman, M.J.

    1975-01-01

    A general purpose computer code has been developed to allow the detailed calculation of evolutionary sequences of hydrostatic stellar models under many circumstances of astrophysical interest. Solution of the structure equations is by the relaxation technique throughout the star without explicit integration and fitting for the outer envelope. A new matrix method of algebraic solution of the finite difference equations is employed, together with a modification of that method for the treatment of the central boundary condition. The method is easily adapted to an integration technique for the construction of initial models. It is demonstrated how the matrix technique allows determination of the derivatives of the matching condition in a single integration. The modification of the code for the purpose of detailed evolutionary calculation of a portion of a star is presented through the modification of the boundary conditions to represent in simple fashion the remainder of the star. Stability and convergence problems encountered in earlier versions of the code are discussed, as well as the techniques used to overcome them. The structure of the code is highly modular, so as to easily accommodate changes in input physics. Following the ad hoc suggestion of Clayton (1974), the calculations were repeated with the high energy tail of the Maxwell distribution of relative ion velocities depleted by various amounts. As an example of the technique of evolving a portion of a star a second application to the solar neutrino problem is made

  13. Neutrino cosmology

    International Nuclear Information System (INIS)

    Berstein, J.

    1984-01-01

    These lectures offer a self-contained review of the role of neutrinos in cosmology. The first part deals with the question 'What is a neutrino.' and describes in a historical context the theoretical ideas and experimental discoveries related to the different types of neutrinos and their properties. The basic differences between the Dirac neutrino and the Majorana neutrino are pointed out and the evidence for different neutrino 'flavours', neutrino mass, and neutrino oscillations is discussed. The second part summarizes current views on cosmology, particularly as they are affected by recent theoretical and experimental advances in high-energy particle physics. Finally, the close relationship between neutrino physics and cosmology is brought out in more detail, to show how cosmological constraints can limit the various theoretical possibilities for neutrinos and, more particularly, how increasing knowledge of neutrino properties can contribute to our understanding of the origin, history, and future of the Universe. The level is that of the beginning graduate student. (orig.)

  14. Decays of supernova neutrinos

    International Nuclear Information System (INIS)

    Lindner, Manfred; Ohlsson, Tommy; Winter, Walter

    2002-01-01

    Supernova neutrinos could be well-suited for probing neutrino decay, since decay may be observed even for very small decay rates or coupling constants. We will introduce an effective operator framework for the combined description of neutrino decay and neutrino oscillations for supernova neutrinos, which can especially take into account two properties: one is the radially symmetric neutrino flux, allowing a decay product to be re-directed towards the observer even if the parent neutrino had a different original direction of propagation. The other is decoherence because of the long baselines for coherently produced neutrinos. We will demonstrate how to use this effective theory to calculate the time-dependent fluxes at the detector. In addition, we will show the implications of a Majoron-like decay model. As a result, we will demonstrate that for certain parameter values one may observe some effects which could also mimic signals similar to the ones expected from supernova models, making it in general harder to separate neutrino and supernova properties

  15. 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.

  16. Naturalness of nearly degenerate neutrinos

    International Nuclear Information System (INIS)

    Casas, J.A.; Espinosa, J.R.; Ibarra, A.; Navarro, I.

    1999-01-01

    If neutrinos are to play a relevant cosmological role, they must be essentially degenerate. We study whether radiative corrections can or cannot be responsible for the small mass splittings, in agreement with all the available experimental data. We perform an exhaustive exploration of the bimaximal mixing scenario, finding that (i) the vacuum oscillations solution to the solar neutrino problem is always excluded; (ii) if the mass matrix is produced by a see-saw mechanism, there are large regions of the parameter space consistent with the large angle MSW solution, providing a natural origin for the Δm sol 2 atm 2 hierarchy; (iii) the bimaximal structure becomes then stable under radiative corrections. We also provide analytical expressions for the mass splittings and mixing angles and present a particularly simple see-saw ansatz consistent with all observations

  17. Neutrino mass matrix

    International Nuclear Information System (INIS)

    Strobel, E.L.

    1985-01-01

    Given the many conflicting experimental results, examination is made of the neutrino mass matrix in order to determine possible masses and mixings. It is assumed that the Dirac mass matrix for the electron, muon, and tau neutrinos is similar in form to those of the quarks and charged leptons, and that the smallness of the observed neutrino masses results from the Gell-Mann-Ramond-Slansky mechanism. Analysis of masses and mixings for the neutrinos is performed using general structures for the Majorana mass matrix. It is shown that if certain tentative experimental results concerning the neutrino masses and mixing angles are confirmed, significant limitations may be placed on the Majorana mass matrix. The most satisfactory simple assumption concerning the Majorana mass matrix is that it is approximately proportional to the Dirac mass matrix. A very recent experimental neutrino mass result and its implications are discussed. Some general properties of matrices with structure similar to the Dirac mass matrices are discussed

  18. Discrete Symmetry Approach to Lepton Flavour, Neutrino Mixing and Leptonic CP Violation, and Neutrino Related Physics Beyond the Standard Theory

    OpenAIRE

    Girardi, Ivan

    2016-01-01

    The experimental evidences of neutrino oscillation, caused by non-zero neutrino masses and neutrino mixing, which were obtained in the experiments with solar, atmospheric, accelerator and reactor neutrinos, opened new field of research in elementary particle physics. The principal goal is to understand at fundamental level the mechanism giving rise to non-zero neutrino masses and neutrino mixing. The open fundamental questions include those of the nature — Dirac or Majorana — of massive neutr...

  19. Probing Exotic Physics With Supernova Neutrinos

    Energy Technology Data Exchange (ETDEWEB)

    Kelso, Chris; Hooper, Dan

    2010-09-01

    Future galactic supernovae will provide an extremely long baseline for studying the properties and interactions of neutrinos. In this paper, we discuss the possibility of using such an event to constrain (or discover) the effects of exotic physics in scenarios that are not currently constrained and are not accessible with reactor or solar neutrino experiments. In particular, we focus on the cases of neutrino decay and quantum decoherence. We calculate the expected signal from a core-collapse supernova in both current and future water Cerenkov, scintillating, and liquid argon detectors, and find that such observations will be capable of distinguishing between many of these scenarios. Additionally, future detectors will be capable of making strong, model-independent conclusions by examining events associated with a galactic supernova's neutronization burst.

  20. Light Sterile Neutrinos: A White Paper

    DEFF Research Database (Denmark)

    Abazajian, K. N.; Acero, M. A.; Agarwalla, S. K.

    2012-01-01

    This white paper addresses the hypothesis of light sterile neutrinos based on recent anomalies observed in neutrino experiments and the latest astrophysical data.......This white paper addresses the hypothesis of light sterile neutrinos based on recent anomalies observed in neutrino experiments and the latest astrophysical data....

  1. Determination of variations of the solar radius from solar eclipse observations

    Science.gov (United States)

    Sofia, S.; Dunham, D. W.; Fiala, A. D.

    1980-01-01

    This paper describes the method to determine the solar radius and its variations from observations made during total solar eclipses. In particular, the procedure to correct the spherical moon predictions for the effects of lunar mountains and valleys on the width and location of the path of totality is addressed in detail. The errors affecting this technique are addressed, a summary of the results of its application to three solar eclipses are presented, and the implications of the results on the constancy of the solar constant are described.

  2. Solar variability observed through changes in solar figure and mean diameter

    International Nuclear Information System (INIS)

    Hill, H.A.

    1984-01-01

    The objective of the project is to detect and monitor climatically significant solar variability by accurate monitoring of the associated variability in solar shape and diameter. The observing program for this project was initiated in 1981. Solar diameter measurements have been taken and data reduction programs for these measurements have been developed. Theoretical analysis of the expected change in the intensity from the solar atmosphere to a given mechanial driving has progressed to the extent that changes in the solar diameter can be related to the associated change in the solar luminosity. An absolute calibration system for the telescope has been constructed and is currently being tested. A proposal is made for the continuation of the work in each of these areas

  3. Solar thermal barometer - EurObserv'ER - May 2016

    International Nuclear Information System (INIS)

    2016-05-01

    In 2015, the European Union saw its solar thermal market contract for the seventh year in a row. EurObserv'ER puts sales of solar thermal capacity installed for the heating market (hot water and space heating) at 1861 MWth, equivalent to a 2.7 million m"2 of collectors... a further 8.6% decrease on the previous year's poor performance. Combined solar thermal capacity installed to date in the EU stands at 34.3 GWth, or 49 million m"2 of collectors

  4. Solar System Observations with the James Webb Space Telescope

    Science.gov (United States)

    Norwood, James; Hammel, Heidi; Milam, Stefanie; Stansberry, John; Lunine, Jonathan; Chanover, Nancy; Hines, Dean; Sonneborn, George; Tiscareno, Matthew; Brown, Michael; hide

    2016-01-01

    The James Webb Space Telescope (JWST) will enable a wealth of new scientific investigations in the near- and mid-infrared, with sensitivity and spatial/spectral resolution greatly surpassing its predecessors. In this paper, we focus upon Solar System science facilitated by JWST, discussing the most current information available concerning JWST instrument properties and observing techniques relevant to planetary science. We also present numerous example observing scenarios for a wide variety of Solar System targets to illustrate the potential of JWST science to the Solar System community. This paper updates and supersedes the Solar System white paper published by the JWST Project in 2010. It is based both on that paper and on a workshop held at the annual meeting of the Division for Planetary Sciences in Reno, NV, in 2012.

  5. Oscillating neutrinos from the Galactic center

    International Nuclear Information System (INIS)

    Crocker, R.M.; Volkas, R.R.; Melia, F.

    1999-11-01

    It has recently been demonstrated that the γ-ray emission spectrum of the EGRET-identified, central Galactic source 2EG J1746-2852 can be well fitted by positing that these photons are generated by the decay of π 0, s produced in p-p scattering at or near an energizing shock. Such scattering also produces charged pions which decay leptonically. The ratio of γ-rays to neutrinos generated by the central Galactic source may be accurately determined and a well-defined and potentially-measurable high energy neutrino flux at Earth is unavoidable. An opportunity, therefore, to detect neutrino oscillations over an unprecedented scale is offered by this source. In this paper we assess the prospects for such an observation with the generation of neutrino Cerenkov telescopes now in the planning stage. We determine that the next generation of detectors may find an oscillation signature in the Galactic Center (GC) signal, but that such an observation will probably not further constrain the oscillation parameter space mapped out by current atmospheric, solar, reactor and accelerator neutrino oscillation experiments

  6. From the measurement of the θ13 mixing angle to the search for geo-neutrinos: studying νe-bare with Double Chooz and Borexino

    International Nuclear Information System (INIS)

    Roncin, Romain

    2014-01-01

    Double Chooz is a reactor neutrino oscillation experiment which aims at measuring the θ 13 mixing angle thanks to two identical detectors located at different distances from the two reactors of the Chooz nuclear power plant, in the French Ardennes. While the near detector will start taking data in fall 2014 to normalize the flux of the neutrinos emitted by the nuclear reactors, the far detector is running since April 2011 and allows to observe the neutrinos disappearance through the neutrino oscillation phenomenon. This thesis is also dedicated to the Borexino experiment which was designed to observe solar neutrinos. Due to its low background level as well as its position in a nuclear free country, Italy, Borexino is also sensitive to geo-neutrinos. This thesis presents both the Double Chooz and Borexino experiments, from the description of the detectors to the main results, with a special attention to the background and its rejection. Studies on the neutrino directionality with these two experiments are also detailed. In the case of Double Chooz, since the neutrinos are coming from the two nuclear reactors, the precision of the analysis method can be assessed. This thesis presents also for the first time the possibility to retrieve the initial direction of the neutrinos when the neutrons created in the inverse beta decay reactions are captured on hydrogen. In the case of Borexino, neutrino directionality information could facilitate the discrimination between geo-neutrinos and neutrinos from nuclear reactors. (author) [fr

  7. First measurement of pp neutrinos in real time in the Borexino detector

    Science.gov (United States)

    Mosteiro, Pablo

    2014-09-01

    The Sun is fueled by a series of nuclear reactions that produce the energy that makes it shine. Neutrinos (nu) produced by these nuclear reactions exit the Sun and reach Earth within minutes, providing us with key information about what goes on at the core of our star. For over twenty years since the first detection of solar neutrinos in the late 1960's, an apparent deficit in their detection rate was known as the Solar Neutrino Problem. Today, the Mikheyev-Smirnov-Wolfenstein (MSW) effect is the accepted mechanism by which neutrinos oscillate inside the Sun, arriving at Earth as a mixture of nue, numu and nutau, the latter two of which were invisible to early detectors. Several experiments have now confirmed the observation of neutrino oscillations. These experiments, when their results are combined together, have demonstrated that neutrino oscillations are well described by the Large Mixing Angle (LMA) solution of the MSW effect. This thesis presents the first measurement of pp neutrinos in the Borexino detector, which is another validation of the LMA-MSW model of neutrino oscillations. In addition, it is one more step towards the completion of the spectroscopy of pp chain neutrinos in Borexino, leaving only the extremely faint hep neutrinos undetected. This advance validates the experiment itself and its previous results. This is, furthermore, the first direct real-time measurement of pp neutrinos. We find a pp neutrino detection rate of 143+/-16 (stat)+/-10 (syst) cpd/100 t in the Borexino experiment, which translates, according to the LMA-MSW model, to (6.42+/-0.85)x1010 cm -2 s-1. We also report on a measurement of neutrons in a dedicated system within the Borexino detector, which resulted in an improved understanding of neutron rates in liquid scintillator detectors at Gran Sasso depths. This result is crucial to the development of novel direct dark matter detection experiments.

  8. Robust Neutrino Constraints by Combining Low Redshift Observations with the CMB

    CERN Document Server

    Reid, Beth A; Jimenez, Raul; Mena, Olga

    2010-01-01

    We illustrate how recently improved low-redshift cosmological measurements can tighten constraints on neutrino properties. In particular we examine the impact of the assumed cosmological model on the constraints. We first consider the new HST H0 = 74.2 +/- 3.6 measurement by Riess et al. (2009) and the sigma8*(Omegam/0.25)^0.41 = 0.832 +/- 0.033 constraint from Rozo et al. (2009) derived from the SDSS maxBCG Cluster Catalog. In a Lambda CDM model and when combined with WMAP5 constraints, these low-redshift measurements constrain sum mnu<0.4 eV at the 95% confidence level. This bound does not relax when allowing for the running of the spectral index or for primordial tensor perturbations. When adding also Supernovae and BAO constraints, we obtain a 95% upper limit of sum mnu<0.3 eV. We test the sensitivity of the neutrino mass constraint to the assumed expansion history by both allowing a dark energy equation of state parameter w to vary, and by studying a model with coupling between dark energy and dark...

  9. Neutrinos and dark energy

    International Nuclear Information System (INIS)

    Schrempp, L.

    2008-02-01

    From the observed late-time acceleration of cosmic expansion arises the quest for the nature of Dark Energy. As has been widely discussed, the cosmic neutrino background naturally qualifies for a connection with the Dark Energy sector and as a result could play a key role for the origin of cosmic acceleration. In this thesis we explore various theoretical aspects and phenomenological consequences arising from non-standard neutrino interactions, which dynamically link the cosmic neutrino background and a slowly-evolving scalar field of the dark sector. In the considered scenario, known as Neutrino Dark Energy, the complex interplay between the neutrinos and the scalar field not only allows to explain cosmic acceleration, but intriguingly, as a distinct signature, also gives rise to dynamical, time-dependent neutrino masses. In a first analysis, we thoroughly investigate an astrophysical high energy neutrino process which is sensitive to neutrino masses. We work out, both semi-analytically and numerically, the generic clear-cut signatures arising from a possible time variation of neutrino masses which we compare to the corresponding results for constant neutrino masses. Finally, we demonstrate that even for the lowest possible neutrino mass scale, it is feasible for the radio telescope LOFAR to reveal a variation of neutrino masses and therefore to probe the nature of Dark Energy within the next decade. A second independent analysis deals with the recently challenged stability of Neutrino Dark Energy against the strong growth of hydrodynamic perturbations, driven by the new scalar force felt between neutrinos. Within the framework of linear cosmological perturbation theory, we derive the equation of motion of the neutrino perturbations in a model-independent way. This equation allows to deduce an analytical stability condition which translates into a comfortable upper bound on the scalar-neutrino coupling which is determined by the ratio of the densities in cold dark

  10. Neutrinos and dark energy

    Energy Technology Data Exchange (ETDEWEB)

    Schrempp, L.

    2008-02-15

    From the observed late-time acceleration of cosmic expansion arises the quest for the nature of Dark Energy. As has been widely discussed, the cosmic neutrino background naturally qualifies for a connection with the Dark Energy sector and as a result could play a key role for the origin of cosmic acceleration. In this thesis we explore various theoretical aspects and phenomenological consequences arising from non-standard neutrino interactions, which dynamically link the cosmic neutrino background and a slowly-evolving scalar field of the dark sector. In the considered scenario, known as Neutrino Dark Energy, the complex interplay between the neutrinos and the scalar field not only allows to explain cosmic acceleration, but intriguingly, as a distinct signature, also gives rise to dynamical, time-dependent neutrino masses. In a first analysis, we thoroughly investigate an astrophysical high energy neutrino process which is sensitive to neutrino masses. We work out, both semi-analytically and numerically, the generic clear-cut signatures arising from a possible time variation of neutrino masses which we compare to the corresponding results for constant neutrino masses. Finally, we demonstrate that even for the lowest possible neutrino mass scale, it is feasible for the radio telescope LOFAR to reveal a variation of neutrino masses and therefore to probe the nature of Dark Energy within the next decade. A second independent analysis deals with the recently challenged stability of Neutrino Dark Energy against the strong growth of hydrodynamic perturbations, driven by the new scalar force felt between neutrinos. Within the framework of linear cosmological perturbation theory, we derive the equation of motion of the neutrino perturbations in a model-independent way. This equation allows to deduce an analytical stability condition which translates into a comfortable upper bound on the scalar-neutrino coupling which is determined by the ratio of the densities in cold dark

  11. Does the Sun appear brighter at night in neutrinos?

    International Nuclear Information System (INIS)

    Bahcall, J.N.; Krastev, P.I.

    1997-01-01

    We calculate accurately the number of solar neutrino events expected as a function of solar zenith angle, with and without neutrino oscillations, for detectors at the locations of Super-Kamiokande, SNO, and the Gran Sasso National Laboratory. Using different Earth models to estimate geophysical uncertainties, and different solar models to estimate solar uncertainties, we evaluate distortions predicted by the Mikheyev-Smirnov-Wolfenstein (MSW) effect in the zenith angle distributions of solar neutrino events. The distortions are caused by oscillations and by ν-e interactions in the Earth that regenerate ν e from ν μ or ν τ . We show that the first two moments of the zenith-angle distribution are more sensitive to the small mixing angle MSW solution than the conventionally studied day-night asymmetry. We present iso-σ contours that illustrate the potential of Super-Kamiokande, SNO, BOREXINO, ICARUS, and HERON/HELLAZ for detecting the Earth regeneration effect at their actual locations (and at the equator). MSW solutions favored by the four pioneering solar neutrino experiments predict characteristic distortions for Super-Kamiokande, SNO, BOREXINO, and ICARUS that range from being unmeasurably small to >5σ (stat) after only a few years of observations. copyright 1997 The American Physical Society

  12. Parametric resonance in neutrino oscillations in matter

    Indian Academy of Sciences (India)

    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 ...

  13. Supersymmetric theories of neutrino dark energy

    International Nuclear Information System (INIS)

    Fardon, Rob; Nelson, Ann E.; Weiner, Neal

    2006-01-01

    We present a supersymmetric model of dark energy from Mass Varying Neutrinos which is stable against radiative corrections to masses and couplings, and free of dynamical instabilities. This is the only such model of dark energy involving fields with significant couplings to any standard model particle. We briefly discuss consequences for neutrino oscillations and solar neutrinos

  14. Planck-scale physics and neutrino masses

    International Nuclear Information System (INIS)

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

    1992-05-01

    We discuss gravitationally induced masses and mass splittings of Majorana, Zeldovich-Konopinski-Mahmoud and Dirac neutrinos. Among other implications, these effects can provide a solution of the solar neutrino puzzle. In particular, we show how this may work in the 17 keV neutrino picture. (author). 18 refs

  15. The Sudbury neutrino observatory

    International Nuclear Information System (INIS)

    McLatchie, W.; Earle, E.D.

    1987-08-01

    This report initially discusses the Homestake Mine Experiment, South Dakota, U.S.A. which has been detecting neutrinos in 38 x 10 litre vats of cleaning fluid containing chlorine since the 1960's. The interation between neutrinos and chlorine produces argon so the number of neutrinos over time can be calculated. However, the number of neutrinos which have been detected represent only one third to one quarter of the expected number i.e. 11 per month rather than 48. It is postulated that the electron-neutrinos originating in the solar core could change into muon- or tau-neutrinos during passage through the high electron densities of the sun. The 'low' results at Homestake could thus be explained by the fact that the experiment is only sensitive to electron-neutrinos. The construction of a heavy water detector is therefore proposed as it would be able to determine the energy of the neutrinos, their time of arrival at the detector and their direction. It is proposed to build the detector at Creighton mine near Sudbury at a depth of 6800 feet below ground level thus shielding the detector from cosmic rays which would completely obscure the neutrino signals from the detector. The report then discusses the facility itself, the budget estimate and the social and economic impact on the surrounding area. At the time of publication the proposal for the Sudbury Neutrino Observatory was due to be submitted for peer review by Oct. 1, 1987 and then to various granting bodies charged with the funding of scientific research in Canada, the U.S.A. and Britain

  16. Observations of Halley's Comet by the Solar Maximum Mission (SMM)

    Science.gov (United States)

    Niedner, M. B.

    1986-01-01

    Solar Maximum Mission coronagraph/polarimeter observations of large scale phenomena in Halley's Comet are discussed. Observations of the hydrogen coma with the UV spectrometer are considered. It is concluded that coronograph/polarimeter observations of the disconnection event, in which the entire plasma tail uproots itself from the head of the comet, is convected away in the solar wind at speeds in the 50 to 100 km/sec range (relative to the head), and is replaced by a plasma tail constructed from folding ion-tail rays, are the most interesting.

  17. Evidence for sterile neutrinos which could be part of dark matter

    International Nuclear Information System (INIS)

    Caldwell, David O.

    2007-01-01

    Limitations on neutrino contribution to dark matter do not apply to the type of sterile neutrino needed to understand solar neutrino flux modulation. These neutrinos couple to active neutrinos via a transition magnetic moment, and if there is any mixing, it is extremely small, avoiding all constraints. The sterile neutrinos result from a Resonant-Spin-Flavor Precession in the convection zone of the Sun, subdominant to the LMA MSW effect, which is at a smaller solar radius. Solar neutrino fluxes measured by the Cl, Ga and Super-Kamiokande (SK) experiments reveal modulations at frequencies related to solar rotation rates. Since the solar magnetic field in the convection zone changes with solar cycle, a rotation frequency seen in GALLEX data would not appear in GNO data. An analysis lumping these data together shows the same frequency not significantly, whereas GALLEX data shows it at the 99.9% CL, using more of the experimental information. Use of insufficient information is a problem in the SK analysis, which sees at low significance the same 3 frequencies (one of rotation and two of related r-modes) we find even at the 99.9% CL when more experimental information is used. SNO looked unsuccessfully for one of these r-mode peaks, but SK data shows this very episodic process had died out before SNO turned on. The statistically significant flux modulation frequencies we observe are all associated with known solar frequencies, attesting to the existence of a sterile neutrino which could aid in understanding small-scale structure, and which might have heavier siblings playing an even larger role in dark matter

  18. Observations of gamma-ray emission in solar flares

    International Nuclear Information System (INIS)

    Forrest, D.J.; Chupp, E.L.; Suri, A.N.; Reppin, C.

    1973-01-01

    This paper reviews the observations of gamma-ray emission made from the OSO-7 satellite in connection with two solar flares in early August 1972. The details of the measurements and a preliminary interpretation of some of the observed features are given. (U.S.)

  19. Solar variability observed through changes in solar figure and mean diameter

    International Nuclear Information System (INIS)

    Hill, H.A.

    1991-01-01

    The work performed on solar variability during 1990 at SCLERA is reviewed. That portion of the SCLERA research program supported by the Department of Energy has been directed toward the detection and monitoring of climatically significant solar variability by accurate measurement of the variability in solar shape and diameter. Observations were obtained in 1990 and results from analysis of earlier observations obtained. The observational evidence of systematic long-term changes in the apparent solar diameter and/or radius has been detected, and these changes continue to strongly correlated with long-term changes in solar total irradiance. Additional evidence for internal gravity modes has been found which may be important to understanding the internal structure of the Sun. Each of these findings shows promise for anticipating future changes in the solar luminosity. Progress has been made in setting up an international network based on SCLERA-type instruments to improve the coverage and quality of the observations. A proposal is made for the continuation of support from the Department of Energy for further studies relevant to solar-variability forecasting

  20. Neutrino masses and neutrino oscillations

    CERN Document Server

    Di Lella, L

    2000-01-01

    These lectures review direct measurements of neutrino masses and the status of neutrino oscillation searches using both natural neutrino sources (the Sun and cosmic rays interacting in the Earth atmosphere) and artificial neutrinos (produced by nuclear reactors and accelerators). Finally, future experiments and plans are presented. (68 refs).