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Sample records for 8b solar neutrino

  1. DETECTING GRAVITY MODES IN THE SOLAR 8 B NEUTRINO FLUX

    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 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 × 10–4. This study clearly shows that due to their high sensitivity to the temperature, the 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 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

  2. 7Be(p, γ)8B and the high-energy solar neutrino flux

    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 7Be(p, γ)8B radiative capture cross section. This reaction produces 8B in the Sun, whose β+ decay is the main source of the high-energy solar neutrinos. Here, the importance of the 7Be(p, γ)8B 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 7Be(p, γ)8B cross section

  3. Borexino: New results on the solar 8B-neutrino flux and outlook on pep- and CNO-neutrinos

    Borexino is a 300 t liquid-scintillator detector designed for the real-time detection of solar neutrinos in the sub-MeV energy range. The experiment is taking data since August 2007 and has published the first real-time spectral measurements of solar 7Be-neutrinos. Based on the statistics of 3 years, Borexino has recently achieved new results for the solar 8B-neutrinos, measuring this rate down to an unprecedented energy threshold of 3 MeV. The measurements of the remaining solar neutrino fluxes of the pep-, CNO- and pp-neutrinos are currently under investigation. The talk presents the new 8B-neutrino results of Borexino and give an outlook on the current efforts on the measurements of the pep- and CNO-neutrinos.

  4. Coulomb dissociation of 8B and solar neutrino problem

    We measured the cross section for Coulomb dissociation of 8B using a radioactive 8B beam of 46.5MeV/u energy with a 208Pb target. The cross section for the 7Be(p,γ)8B capture reaction was deduced at Ecm=0.6-1.7MeV. The extracted astrophysical S17 factors were consistent with the values measured by Vaughn et al. and Filippone et al. Possible corrections due to 7Be excited state population, E1 and M2 contribution, nuclear contribution and post acceleration effects are considered. ((orig.))

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

    Ianni, A; Villante, F L

    2016-01-01

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

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

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

    2011-01-01

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

  7. Indirect measurements of the solar-neutrino production reaction 7Be(p,γ)8B

    Low-energy cross sections of the 7Be(p,γ)8B reaction is of crucial importance, because they determine the high-energy solar neutrino flux. Coulomb dissociation with intermediate-energy 8B beams and low-energy proton-transfer reactions with 7Be beams have been investigated to determine indirectly the astrophysical S17 factors of the 7Be(p,γ)8B reaction. The results of these studies are generally in good agreement with the ones obtained by direct capture measurements using intense proton beams and radioactive 7Be targets

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

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

    2005-01-01

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

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

    The Sudbury Neutrino Observatory (SNO) has precisely determined the total active (vx)8B solar neutrino flux without assumptions about the energy dependence of the ve survival probability. The measurements were made with dissolved NaCl in the heavy water to enhance the sensitivity and signature for neutral-current interactions. The flux is found to be 5.21+-0.27 (stat)+-0.38(syst)x10-6 cm-2s-1, in agreement with previous measurements and standard solar models. A global analysis of these and other solar and reactor neutrino results yields Δm2 = 7.1+1.2-0.6 x 10-5 eV2 and θ 32.5+2.4-2.3 degrees. Maximal mixing is rejected at the equivalent of 5.4 standard deviations

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

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

    2004-01-01

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

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

    Peeters, Simon; SNO Collaboration,

    2008-01-01

    The Sudbury Neutrino Observatory (SNO) used an array of 3He proportional counters to measure the rate of neutral-current interactions in heavy water and precisely determined the total active (nu_x) 8B solar neutrino flux. This technique is independent of previous methods employed by SNO. The total flux is found to be 5.54(+0.33/-0.31 stat, +0.36/-0.34 syst) x 10^6 cm^-2 s^-1, in agreement with previous measurements and standard solar models. A global analysis of solar and reactor neutrino res...

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

    Evidence is presented which indicates that the accepted value for the cross section of the 7Be(p,γ)8B reaction at stellar energies is probably too large. It is suggested that the accepted value of the 7Li(d,p)8Li cross section, which has been used for normalization purposes, is too large; that the accepted value for the ratio of the 7Be(p,γ)8B and 7Li(d,p)8Li 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 7Be(p,γ)8B 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

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

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

    2008-01-01

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

  14. Measurement of the solar 8B neutrino flux with 246 live days of Borexino and observation of the MSW vacuum-matter transition

    Bellini, G; Bonetti, S; Buizza Avanzini, M; Caccianiga, B; Cadonati, L; Calaprice, F; Carraro, C; Chavarria, A; Dalnoki-Veress, F; D'Angelo, D; De Kerret, H; Derbin, A; Etenko, A; Fomenko, K; Franco, D; Galbiati, C; Gazzana, S; Giammarchi, M; Goeger-Neff, M; Goretti, A; Grieb, C; Hardy, a S; Aldo, Ianni; Andrea, Ianni; Joyce, M; Kobychev, V; Korga, G; Kryn, D; Laubenstein, M; Leung, M; Lewke, T; Litvinovich, E; Loer, B; Lombardi, P; Ludhova, L; Machulin, I; Manecki, S; Maneschg, W; Manuzio, G; Masetti, F; McCarty, K; Meindl, Q; Meroni, E; Miramonti, L; Misiaszek, M; Montanari, D; Muratova, V; Oberauer, L; Obolensky, M; Ortica, F; Pallavicini, M; Papp, L; Perasso, L; Perasso, S; Pocar, A; Raghavan, b R S; Ranucci, G; Razeto, A; Risso, P; Romani, A; Rountree, D; Sabelnikov, A; Saldanha, R; Salvo, C; Schönert, S; Simgen, H; Skorokhvatov, M; Smirnov, O; Sotnikov, A; Sukhotin, S; Suvorov, Y; Tartaglia, R; Testera, G; Vignaud, D; Vogelaar, R B; Von Feilitzsch, F; Wójcik, M; Wurm, M; Zaimidoroga, O; Zavatarelli, S; Zuzel, G

    2008-01-01

    We report the measurement of the 8B solar neutrinos interaction rate with the Borexino detector. The threshold energy of 2.8 MeV is the lowest for 8B achieved so far. The rate of 8B solar neutrino interaction as measured through their scattering on the target electrons is 0.26+-0.04(stat)+-0.02(syst) c/d/100 tons. This corresponds to an equivalent electron neutrino flux of (2.65+-0.44(stat)+-0.18(syst))x10^6 cm^-2 s^-1, as derived from the elastic scattering only, in good agreement with existing measurements and predictions. The corresponding 8B mean electron neutrino survival probability, assuming the BS07(GS98) Standard Solar Model, is 0.35+-0.10 at the effective energy of 8.6 MeV. The survival probability of the 0.862 MeV 7Be neutrinos was previously reported with a subset of these data as 0.56+-0.10. Eliminating the common sources of systematic errors, the ratio between the measured survival probabilities for 7Be and 8B neutrinos is 1.60+-0.33, 1.8 sigmas different form unity. For the first time we confir...

  15. Measurement of the nue and Total 8B Solar Neutrino Fluxes with theSudbury Neutrino Observatory Phase I Data Set

    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.

  16. The 3He(alpha, gamma)7Be reaction rate, solar 7Be and 8B neutrino fluxes, and the production of 7Li during the Big Bang

    The 3He(α,γ)7Be reaction plays an important role both in determining the predicted fluxes of 7Be and 8B neutrinos from our Sun, and in the calculation of primordial 7Li production. In light of the highly precise determination of the baryon-to-photon ratio from the cosmic microwave background data, it is necessary to re-determine primordial 7Li production. Recent experimental nuclear astrophysics work has led to an improved determination of the 3He(α,γ)7Be cross section, with several experiments clustered at E = 0.5 MeV center-of-mass energy and above [2, and references therein]. On the other hand, precisely calibrated 7Be and 8B neutrino fluxes from the Sun are now available. Assuming the accepted solar central temperature to be correct, the neutrino flux data can be used to determine the 3He(α,γ)7Be cross section at the solar Gamow peak, E = 0.03 MeV. The energy range relevant for Big Bang 7Li production lies just between 0.03 and 0.5 MeV. The poster aims to use the two above described levels in order to improve the precision of the predicted primordial abundance of 7Li. It updates a previous work that appeared before the new cross section, solar neutrino and microwave background data were available. (author)

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

    The 8B produced inside the sun through the reaction 7Be(p,γ)8B 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 7Be(p,γ)8B, because the neutrinos flux of 8B 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 S17(0) is 19.21.3 EV-B, which leads to a significant reduction of the uncertainty on the high energy neutrinos flux of 8B. (J.S.)

  18. Molybdenum solar neutrino experiment

    The goal of the molybdenum solar neutrino experiment is to deduce the 8B solar neutrino flux, averaged over the past several million years, from the concentration of 98Tc 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 8B 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 98Tc (4.2 Myr), also produced by 8B neutrinos, and possibly 97Tc (2.6 Myr), produced by lower energy neutrinos

  19. Measurement of the efficient cross section of the reaction {sup 7}Be(p, {gamma}){sup 8}B at low energies and implications in the problem of solar neutrinos; Mesures de la section efficace de la reaction {sup 7}Be(p,{gamma}){sup 8}B a basses energies et implications dans le probleme des neutrinos solaires

    Hammache, Fairouz

    1999-07-01

    The {sup 8}B produced inside the sun through the reaction {sup 7}Be(p,{gamma}){sup 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 {sup 7}Be(p,{gamma}){sup 8}B, because the neutrinos flux of {sup 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{sub 17}(0) is 19.21.3 EV-B, which leads to a significant reduction of the uncertainty on the high energy neutrinos flux of {sup 8}B. (J.S.)

  20. Electron Energy Spectra, Fluxes, and Day-Night Asymmetries of $^{8}$B Solar Neutrinos from the 391-Day Salt Phase SNO Data Set

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

    2005-01-01

    Results are reported from the complete salt phase of the Sudbury Neutrino Observatory experiment in which NaCl was dissolved in the D$_2$O target. The addition of salt enhanced the signal from neutron capture, as compared to the pure D$_2$O detector. By making a statistical separation of charged-current events from other types based on event-isotropy criteria, the effective electron recoil energy spectrum has been extracted. In units of $ 10^6$ cm$^{-2}$ s$^{-1}$, the total flux of active-flavor neutrinos from $^8$B decay in the Sun is found to be $4.94^{+0.21}_{-0.21}{(stat)}^{+0.38}_{-0.34}{(syst)}$ and the integral flux of electron neutrinos for an undistorted $^8$B spectrum is $1.68^{+0.06}_{-0.06}{(stat)}^{+0.08}_{-0.09}{(syst)}$; the signal from ($\

  1. Searches for high frequency variations in the 8-B neutrino flux at the Sudbury neutrino observatory

    Rielage, Keith [Los Alamos National Laboratory; Seibert, Stanley R [Los Alamos National Laboratory; Hime, Andrew [Los Alamos National Laboratory; Elliott, Steven R [Los Alamos National Laboratory; Stonehill, L C [Los Alamos National Laboratory; Wouters, J M [Los Alamos National Laboratory; Aharmim, B [LAURENTIAN UNIV; Ahmed, S N [QUEEN' S UNIV; Anthony, A E [UNIV OF TEXAS; Barros, N [PORTUGAL; Beier, E W [UNIV OF PA; Bellerive, A [CARLETON UNIV; Belttran, B [UNIV OF ALBERTA; Bergevin, M [LBNL; Biller, S D [UNIV OF OXFORD; Boudjemline, K [CARLETON UNIV; Burritt, T H [UNIV OF WASHINGTON; Cai, B [QUEEN' S UNIV; Chan, Y D [LBNL; Chauhan, D [LAURENTIAN UNIV; Chen, M [QUEEN' S UNIV; Cleveland, B T [UNIV OF OXFORD; Cox - Mobrand, G A [UNIV OF WASHINGTON; Dai, X [QUEEN' S UNIV; Deng, H [UNIV OF PA; Detwiler, J [LBNL; Dimarco, M [QUEEN' S UNIV; Doe, P J [UNIV OF WASHINGTON; Drouin, P - L [CARLTON UNIV; Duba, C A [UNIV OF WASHINGTON; Duncan, F A [SNOLAB, SUDBURY; Dunford, M [UNIV OF PA; Earle, E D [QUEEN' S UNIV; Evans, H C [QUEEN' S UNIV; Ewan, G T [QUEEN' S UNIV; Farine, J [LAURENTTIAN UNIV; Fergani, H [UNIV OF OXFORD; Fleurot, F [LAURENTIAN UNIV; Ford, R J [SNOLAB, SUDBURY; Formaggilo, J A [MASSACHUSETTS INST. OF TECH.; Gagnon, N [UNIV OF WASHINGTON; Goon, J Tm [LOUISIANA STATE UNIV; Guillian, E [QUEEN' S UNIV; Habib, S [UNIV OF ALBERTA; Hahn, R L [BNL; Hallin, A L [UNIV OF ALBERTA; Hallman, E D [LAURENTIAN UNIV; Harvey, P J [QUEEN' S UNIV; Hazama, R [UNIV OF WASHINGTON; Heintzelman, W J [UNIV OF PA; Heise, J [SNOLAB, SUDBURY; Helmer, R L [TRIUMF; Howard, C [UNIV OF ALBERTA; Howe, M A [UNIV OF WASHINGTON; Huang, M [UNIV OF TEXAS; Jamieson, B [UNIV OF BRITISH COLUMBIA; Jelley, N A [UNIV OF OXFORD; Keeter, K J [SNOLAB, SUDBURY; Klein, J R [UNIV OF TEXAS; Kos, M [QUEEN' S UNIV; Kraus, C [QUEEN' S UNIV; Krauss, C B [UNIV OF ALBERTA; Kutter, T [LOUISIANA STATE UNIV; Kyba, C C M [UNIV OF PA; Law, J [UNIV OF GUELPH; Lawson, I T [SNOLAB, SUDBURY; Lesko, K T [LBNL; Leslie, J R [QUEEN' S UNIV; Loach, J C [UNIV OF OXFORD; Maclellan, R [QUEEN' S UNIV; Majerus, S [UNIV OF OXFORD; Mak, H B [QUEEN' S UNIV; Maneira, J [PORTUGAL; Martin, R [QUEEN' S UNIV; Mccauley, N [UNIV OF PA; Mc Donald, A B [QUEEN' S UNIV; Mcgee, S [UNIV OF WASHINGTON; Miffin, C [CARLETON UNIV; Miller, M L [MASSACHUSETTS INST. OF TECH.; Monreal, B [MASSACHUSETTS INST. OF TECH.; Monroe, J [MASSACHUSETTS INST. OF TECH; Morissette, B [SNOLAB, SUDBURY; Nickel, B G [UNIV OF GUELPH; Noble, A J [QUEEN' S UNIV; O' Keeffe, H M [UNIV OF OXFORD; Oblath, N S [UNIV OF WASHINGTON; Orebi Gann, G D [UNIV OF OXFORD; Oser, S M [UNIV OF BRITISH COLUMBIA; Ott, R A [MASSACHUSETTS INST. OF TECH.; Peeters, S J M [UNIV OF OXFORD; Poon, A W P [LBNL; Prior, G [LBNL; Reitzner, S D [UNIV OF GUELPH; Robertson, B C [QUEEN' S UNIV; Robertson, R G H [UNIV OF WASHINGTON; Rollin, E [CARLETON UNIV; Schwendener, M H [LAURENTIAN UNIV; Secrest, J A [UNIV OF PA; Seibert, S R [UNIV OF TEXAS; Simard, O [CARLETON UNIV; Sinclair, D [CARLETON UNIV; Sinclair, L [CARLETON UNIV; Skensved, P [QUEEN' S UNIV; Sonley, T J [MASSACHUSETTS INST. OF TECH.; Tesic, G [CARLETON UNIV; Tolich, N [UNIV OF WASHINGTON; Tsui, T [UNIV OF BRITISH COLUMBIA; Tunnell, C D [UNIV OF TEXAS; Van Berg, R [UNIV OF PA; Van Devender, B A [UNIV OF WASHINGTON; Virtue, C J [LAURENTIAN UNIV; Wall, B L [UNIV OF WASHINGTON; Waller, D [CARLETON UNIV; Wan Chan Tseung, H [UNIV OF OXFORD; West, N [UNIV OF OXFORD; Wilkerson, J F [UNIV OF WASHINGTON; Wilson, J R [UNIV OF OXFORD; Wright, A [QUEEN' S UNIV; Yeh, M [BNL; Zhang, F [CARLETON UNIV; Zuber, K [UNIV OF OXFORD

    2009-01-01

    We have peformed three searches for high-frequency signals in the solar neutrino flux measured by the Sudbury Neutrino Observatory (SNO), motivated by the possibility that solar g-mode oscillations could affect the production or propagation of solar {sup 8}B neutrinos. The first search looked for any significant peak in the frequency range l/day to 144/day, with a sensitivity to sinusoidal signals with amplitudes of 12% or greater. The second search focused on regions in which g-mode signals have been claimed by experiments aboard the SoHO satellite, and was sensitive to signals with amplitudes of 10% or greater. The third search looked for extra power across the entire frequency band. No statistically significant signal was detected in any of the three searches.

  2. Searches for high frequency variations in the 8-B neutrino flux at the Sudbury neutrino observatory

    We have peformed three searches for high-frequency signals in the solar neutrino flux measured by the Sudbury Neutrino Observatory (SNO), motivated by the possibility that solar g-mode oscillations could affect the production or propagation of solar 8B neutrinos. The first search looked for any significant peak in the frequency range l/day to 144/day, with a sensitivity to sinusoidal signals with amplitudes of 12% or greater. The second search focused on regions in which g-mode signals have been claimed by experiments aboard the SoHO satellite, and was sensitive to signals with amplitudes of 10% or greater. The third search looked for extra power across the entire frequency band. No statistically significant signal was detected in any of the three searches.

  3. Electron energy spectra, fluxes, and day-night asymmetries of 8B solar neutrinos from the 391-day salt phase SNO data set

    The first phase of the Sudbury Neutrino Observatory, proved that neutrinos change flavour on the way from the sun to the earth, and improved significantly the evidence that neutrinos oscillate. From June 2001 the Sudbury Neutrino Observatory ran with 2000 kg of NaCl added to its 1000 tonnes heavy water target until October 2003. The addition of salt enhanced SNO's ability to detect solar neutrinos in several ways: it improved the neutral current measurement, as well as allowing a better statistical separation of neutral current and charged current events. In this talk I will discuss the experimental aspects of the second phase of the SNO experiment and the resulting measurements presented in the publication of March this year. I'll also give an outlook of the third phase of the SNO experiment which has just started and will continue until december 2006. (author)

  4. Solar neutrinos

    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 37Cl 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)

  5. Solar Neutrinos

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

    1964-12-01

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

  6. Solar Neutrinos

    Bellini, G.; Ranucci, G.

    2010-01-01

    Solar neutrino investigation has represented one of the most active field of particle physics over the past decade, accumulating important and sometimes unexpected achievements. After reviewing some of the most recent impressive successes, the future perspectives of this exciting area of neutrino research will be discussed.

  7. Calibration Of Sno For The Detection Of (8)b Neutrinos

    Ford, R J

    1999-01-01

    The Sudbury Neutrino Observatory (SNO) is a second generation water Čerenkov detector using 1000 tonnes of heavy water to study neutrino astrophysics. Using deuterium neutrino reactions, SNO will measure the flux and energy spectrum of solar electron neutrinos, and will measure the flavour-blind flux of neutrinos. A nitrogen/multi-dye laser diffuser ball has been designed and installed in SNO for calibration of the electronics, photomultiplier tubes (PMTs) and optical parameters. The laser provides pulsed radiation at 337.1 nm with a 600 psec width and pulse rate up to 50 Hz. The laser can be used directly or as a pump for one of four dye laser resonators, which provides five wavelength selections from 337–500 nm. The light is delivered to a pseudo-isotropic diffuser ball (the laserball) by a 100 μm UV-VIS fibre bundle with less than 1 nsec dispersion at 337 nm. The laserball can be deployed throughout the detector with the rope manipulator system. The laserball output is adjustabl...

  8. Solar Neutrino Physics

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

  9. Solar Neutrino Physics

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

    1999-07-15

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

  10. Solar neutrinos and neutrino physics

    Maltoni, Michele; Smirnov, Alexei Yu.

    2016-04-01

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

  11. Solar Neutrino Problem

    Davis, R. Jr.; Evans, J. C.; Cleveland, B. T.

    1978-04-28

    A summary of the results of the Brookhaven solar neutrino experiment is given and discussed in relation to solar model calculations. A review is given of the merits of various new solar neutrino detectors that were proposed.

  12. How many solar neutrino experiments are wrong?

    Bahcall, J N

    1994-01-01

    Ten recently-published solar models give \\7be neutrino fluxes that lie within a range of \\pm 10\\% of the average value, a convergence that is independent of uncertainties in the measured laboratory rate of the \\7be(p,\\gamma)\\8b reaction. If nothing happens to solar neutrinos after they are created ({\\it a la} standard electroweak theory) and the operating solar neutrino experiments are correct, then the \\7be solar neutrino flux must be less than 50\\% of the solar model value. At least three of the four existing solar neutrino experiments must be wrong {\\it if}: (1) standard electroweak theory is correct, and (2) the true \\7be neutrino flux lies within the range predicted by standard solar models.

  13. Solar neutrino oscillations

    The special properties of solar neutrinos that render this flux so uniquely important in searches for neutrino masses and flavor mixing are reviewed. The effects of matter, including density fluctuations and turbulence, on solar neutrino oscillations are explained through analogies with more familiar atomic physics phenomena

  14. The Solar Neutrino Problem An Update

    Dar, Arnon; Dar, Arnon; Shaviv, Giora

    1999-01-01

    The $^8$B solar neutrino flux as measured by Super-Kamiokande is consistent with the $^{37}$Ar production rate in $^{37}$Cl at Homestake. GALLEX and SAGE, continue to observe $^{71}$Ge production rates in $^{71}$Ga that are consistent with the minimal signal expected from the solar luminosity. The observed $^8$B solar neutrino flux is in good agreement with that predicted by the standard solar model of Dar and Shaviv with nuclear reaction rates that are supported by recent measurements of nuclear fusion cross sections at low energies. The measurements of Super-Kamiokande, SAGE and GALLEX suggest that the expected the pep, $^7$Be and NO solar neutrino fluxes are strongly suppressed. This can be explained by neutrino oscillations and the Mikheyev-Smirnov-Wolfenstein effect. Since neither a flavor change, nor a terrestrial variation, nor a spectral distortion of the $^8$B solar neutrino flux has been observed yet, the solar neutrino problem does not provide conclusive evidence for neutrino properties beyond the ...

  15. The solar neutrino puzzle: Mapping a solution

    Remarkable progress has been made over the past 30 years in understanding the flux of neutrinos coming from the sun. The so-called 'solar neutrino puzzle', whereby the total number of electron neutrinos from the sun does not match the expected total neutrino yield can be now understood in the context of neutrino flavor transformations. The Sudbury Neutrino Observatory has contributed to understanding the solar neutrino problem by measuring both the electron and non-electron components of the solar neutrino flux. The Sudbury Neutrino Observatory is a 1000 T D2O Cerenkov detector that is sensitive to 8B neutrinos produced in the sun. By using the energy, radius, and direction with respect to the sun, the SNO experiment can separately determine the rates of the charged current, neutral current and electron scattering reactions of neutrinos on deuterium. Assuming an undistorted 8B spectrum, the ve component of the 8B solar flux is φe 1.76-0.05+0.05(stat.)-0.09+0.09 (syst.) x 106 cm-2s-1 based on events with a measured kinetic energy above 5 MeV. The non-ve component is φμτ 3.41-0.45+0.45(stat.)-0.45+0.48 (syst.) x 106 cm-2s-1, 5.3σ greater than zero, providing strong evidence for solar ve flavor transformation. The total flux measured with the NC reaction is φNC = 5.09-0.43+0.44(stat.)-0.43+0.46 (syst.) x 106 cm-2s-1, consistent with the Standard Solar Model. A global solar neutrino analysis in terms of matter-enhanced oscillations of two active flavors strongly favors the Large Mixing Angle (LMA) solution

  16. The solar neutrinos epopee

    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 ...

  17. Solar neutrino experiments

    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 Neutrino Observables Sensitive to Matter Effects

    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.

  19. Astrophysical Solutions are Incompatible with the Solar Neutrino Data

    Bludman, S.; Hata, N; Langacker, P.

    1993-01-01

    We consider the most general solar model, using the neutrino fluxes as free parameters constrained only by the solar luminosity, and show that the combined solar neutrino data exclude any astrophysical solution at 98\\% C.L.\\ Our best fit to the $^7$Be and $^8$B fluxes is respectively $

  20. Solar neutrino detection

    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.

  1. The solar neutrinos epopee

    The 2002 year has been fruitful for the neutrino physics. First, the Sudbury Neutrino Observatory (SNO) experiment has shown that the electron neutrinos νe emitted by the sun are converted into muon neutrinos (νμ) and tau neutrinos (ντ), 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.)

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

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

    1992-01-01

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

  3. The molybdenum solar neutrino experiment

    The only new solar neutrino measurement which is actively underway at this time is the Mo geological experiment. This experiment measures the high energy 8B neutrinos, as does the 37Cl experiment but because the products are very long-lived, their concentrations in the ore should be related to the average condition in the interior of the sun over approximately the past 10 million years. The absorption of a neutrino in the 9.6% abundant 97Mo isotope produces 97Tc (half-life of 2.6 x 106y) and in 24.1% abundant 98Mo, 98Tc (4.2 x 106y). Several conditions must be met before it can be assumed that measurements of the long-lived Tc isotopes in Mo ore will result in a usefully accurate value for the solar neutrino flux. There is only one known suitable source of molybdenum ore, in Colorado. The separation procedure to obtain the Tc isotopes and the use of resonance ionization mass spectroscopy for the isotope analysis are not yet sensitive enough. However, improvements are possible and are currently being investigated. (U.K.)

  4. The solar neutrino problem

    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.)

  5. Radiochemical solar neutrino experiments

    Radiochemical experiments have been crucial to solar neutrino research. Even today, they provide the only direct measurement of the rate of the proton-proton fusion reaction, p+p→d+e++νe, which generates most of the Sun's energy. We first give a little history of radiochemical solar neutrino experiments with emphasis on the gallium experiment SAGE - the only currently operating detector of this type. The combined result of all data from the Ga experiments is a capture rate of 67.6±3.7 SNU. For comparison to theory, we use the calculated flux at the Sun from a standard solar model, take into account neutrino propagation from the Sun to the Earth and the results of neutrino source experiments with Ga, and obtain 67.3-3.5+3.9 SNU. Using the data from all solar neutrino experiments we calculate an electron neutrino pp flux of φpp♁=(3.41-0.77+0.76)×1010/(cm2-s), which agrees well with the prediction from a detailed solar model of φpp♁=(3.30-0.14+0.13)×1010/(cm2-s). Four tests of the Ga experiments have been carried out with very intense reactor-produced neutrino sources and the ratio of observed to calculated rates is 0.88±0.05. One explanation for this unexpectedly low result is that the cross section for neutrino capture by the two lowest-lying excited states in 71Ge has been overestimated. We end with consideration of possible time variation in the Ga experiments and an enumeration of other possible radiochemical experiments that might have been.

  6. Solar Neutrinos. II. Experimental

    Davis, Raymond Jr.

    1964-01-01

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

  7. Solar neutrinos: beyond standard solar models

    Castellani, V.; Degl'Innocenti, S.; Fiorentini, G.; Lissia, M.; Ricci, B.

    1996-01-01

    After a short survey of the physics of solar neutrinos, giving an overview of hydrogen burning reactions, predictions of standard solar models and results of solar neutrino experiments, we discuss the solar-model-independent indications in favour of non-standard neutrino properties. The experimental results look to be in contradiction with each other, even disregarding some experiment: unless electron neutrinos disappear in their trip from the sun to the earth, the fluxes of intermediate ener...

  8. SNO and future solar neutrino experiments

    The SNO Collaboration has completed a combined analysis of 8B solar neutrino data from all three phases of the project. The combined analysis resulted in a total flux of active neutrino flavors from 8B decays in the sun of 5.25±0.16(stat.)−0.13+0.11(syst.)×106cm2s−1. A three-flavor neutrino oscillation analysis combining the SNO results with results of all other solar neutrino experiments and the KamLAND experiment yielded Δm212=(7.41−0.19+0.21)×10−5eV2, tan2θ12=0.446−0.029+0.030, and sin2θ13=(2.5−1.5+1.8)×10−2. The results of the SNO analysis will be presented, along with a discussion of future projects that will seek to study lower energy neutrinos to improve on our knowledge of the properties of neutrinos and the sun

  9. Solar models and solar neutrino oscillations

    Bahcall, John N.; Peña Garay, Carlos

    2004-01-01

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

  10. Solar neutrino observations and neutrino oscillations

    The results of recent Kamiokande-II and 37Cl 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

  11. Solar neutrino oscillation phenomenology

    Srubabati Goswami

    2004-02-01

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

  12. Chlorine solar neutrino experiment

    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 37Ar and the question of the constancy of the production rate of 37Ar are given special emphasis

  13. Helioseismology, solar models and solar neutrinos

    Fiorentini, G; B. Ricci

    1999-01-01

    We review recent advances concerning helioseismology, solar models and solar neutrinos. Particularly we shall address the following points: i) helioseismic tests of recent SSMs; ii)the accuracy of the helioseismic determination of the sound speed near the solar center; iii)predictions of neutrino fluxes based on helioseismology, (almost) independent of SSMs; iv)helioseismic tests of exotic solar models.

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

    Bahcall, J N; Bahcall, John N.

    2004-01-01

    Solar model predictions of 8B and p-p neutrinos agree with the experimentally-determined fluxes (including oscillations): phi(pp)_{measured} = (1.02 +- 0.02 +- 0.01)phi(pp)_{theory}, and phi(8B)_{measured} =(0.88 +- .04 +- 0.23)phi(8B)_{theory}, 1 sigma experimental and theoretical uncertainties, respectively. We use improved input data for nuclear fusion reactions, the equation of state, and the chemical composition of the Sun. The solar composition is the dominant uncertainty in calculating the 8B and CNO neutrino fluxes; the cross section for the 3He(4He, gamma)7Be reaction is the largest uncertainty for the calculated 7Be neutrino flux.

  15. Standard physics solution to the solar neutrino problem?

    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.

  16. Report of the Solar and Atmospheric Neutrino Working Group

    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 8B 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 νe, which also permits sensitive tests for sterile neutrinos. The pp experiment will also permit a significantly improved determination of θ12 and, together with other solar neutrino measurements, either a measurement of θ13 or a constraint a factor of two lower than existing bounds. In combination with the essential pre-requisite experiments that will measure the 7Be 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 7Be 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

  17. Report of the Solar and Atmospheric Neutrino Working Group

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

    2004-10-22

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

  18. The indium solar neutrino project

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

  19. Proposed geological solar neutrino measurement

    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

  20. Halo effective field theory constrains the solar 7Be + p → 8B + γ rate

    Zhang, Xilin; Nollett, Kenneth M.; Phillips, D. R.

    2015-12-01

    We report an improved low-energy extrapolation of the cross section for the process 7Be (p , γ)8B, which determines the 8B neutrino flux from the Sun. Our extrapolant is derived from Halo Effective Field Theory (EFT) at next-to-leading order. We apply Bayesian methods to determine the EFT parameters and the low-energy S-factor, using measured cross sections and scattering lengths as inputs. Asymptotic normalization coefficients of 8B are tightly constrained by existing radiative capture data, and contributions to the cross section beyond external direct capture are detected in the data at E EFT subsumes all models into a controlled low-energy approximant, where they are characterized by nine parameters at next-to-leading order. These are fit to data, and marginalized over via Monte Carlo integration to produce the improved prediction for S (E).

  1. Solar and supernova neutrino interactions

    Two topics are addressed, the interactions of neutrinos during a type II supernova and the effect of current eddies on solar neutrino oscillations. The supernova discussion focuses on the nucleosynthesis that accompanies inelastic neutral current interactions of neutrinos in the mantle of a collapsing star, and on the effect of neutrino ''down-scattering'' and preheating on the explosion mechanism. The second half of the talk deals with the influence of solar turbulence (or density fluctuations) on the neutrino effective mass and the possibility that a time-varying neutrino flux could result. The effects of harmonic density or three-current perturbations on the oscillation probability are explored analytically and numerically. 15 refs., 5 figs

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

    Bellini, Gianpaolo

    2016-07-01

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

  3. A xenon solar neutrino detector

    Georgadze, A. Sh.; Klapdor-Kleingrothaus, H. V.; Päs, H.; Zdesenko, Yu. G.

    1997-06-01

    The neutrino capture by 131Xe with the threshold at 352 keV as reaction to detect solar neutrinos is examined. The most important feature of this process is its high sensitivity to beryllium neutrinos, that contribute approximately 40% to the total capture rate predicted in the Standard Solar Model (45 SNU). Also the procedure of extraction of the daughter cesium atoms from liquid xenon as well as other technical problems concerning preparation of the cesium sample, low background measurements and side reactions for a possible realization as a solar neutrino detector are discussed. The expected counting rate from the SSM for a xenon detector is ≈ 1500 events/yr·kt. Combining the results of such a detector with other experimental data it will be possible to test the existence of vacuum oscillations and the MSW effect and/or input parameters of the Standard Solar Models.

  4. Solar neutrino results from SAGE

    The solar neutrino capture rate measured by the Russian-American Gallium Experiment on metallic gallium during the period January 1990 through December 1997 is (67.2-7.0-3.0+7.2+3.5) SNU, where the uncertainties are statistical and systematic, respectively. This result represents a 7 σ depression in the neutrino flux compared with predicted standard solar model rates. The experimental procedures and data analysis are presented

  5. The gallium solar neutrino experiment

    The overwhelming majority of solar neutrinos are low energy pp-neutrinos. Among the few potential experiments for their detection, the radiochemical Gallium Solar Neutrino experiment is the only one which has been demonstrated to be feasible. The strong motivations for performing such an experiment, the experimental approach, the major results of the pilot experiment performed in an international collaboration, recent progress in further reducing the counter backgrounds, experiments towards Resonance Ionization of Gallium for ultimate background reduction, the status of the project, and the plans for the future are all described. (author)

  6. Solar neutrino results from SAGE

    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 51Cr experiment to check the response of SAGE to low energy neutrinos is also presented

  7. Solar monopoles and terrestrial neutrinos

    Magnetic monopoles captured in the core of the sun may give rise to a substantial flux of energetic neutrinos by catalyzing the decay of solar hydrogen. We discuss the expected neutrino flux in underground detectors under different assumptions about solar interior conditions. Although a monopole flux as low as F/sub M/ /approximately/ 10/sup /minus/24/ cm/sup /minus/2/ sec/sup /minus/1/ sr/sup /minus/1/ could give rise to a neutrino flux above atmospheric background, due to M/bar M/ annihilation, this does not translate into a reliable monopole flux bound stronger than the Parker limit. 8 refs., 1 fig

  8. Solar monopoles and terrestrial neutrinos

    Frieman, J.

    1988-04-01

    Magnetic monopoles captured in the core of the sun may give rise to a substantial flux of energetic neutrinos by catalyzing the decay of solar hydrogen. We discuss the expected neutrino flux in underground detectors under different assumptions about solar interior conditions. Although a monopole flux as low as F/sub M/ /approximately/ 10/sup /minus/24/ cm/sup /minus/2/ sec/sup /minus/1/ sr/sup /minus/1/ could give rise to a neutrino flux above atmospheric background, due to M/bar M/ annihilation, this does not translate into a reliable monopole flux bound stronger than the Parker limit. 8 refs., 1 fig.

  9. What do solar neutrino experiments teach us about physics?

    The predictions of the standard model (solar and electroweak) for solar neutrino experiments will be described, with special emphasis on quantitative estimates of the uncertainties in the predictions. An argument--which uses detailed Monte Carlo studies of the solar-model-predictions--will be presented which demonstrates that the existing solar neutrino experiments cannot be reconciled unless new weak interaction physics changes the shape of the 8Be neutrino energy spectrum. Additional arguments that suggest that new physics is required will be summarized. The predictions for next-generation experiments that are independent of details of solar models will be highlighted. An urgent appeal will be made for performing a measurement of the p(7Be, γ)8B reaction using a radioactive beam of 7Be

  10. Solar neutrino results from SAGE

    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

  11. Solar neutrino results from SAGE

    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

  12. Measurement of the Solar Neutrino Energy Spectrum Using Neutrino-Electron Scattering

    A measurement of the energy spectrum of recoil electrons from solar neutrino scattering in the Super-Kamiokande detector is presented. The results shown here were obtained from 504 days of data taken between 31 May 1996 and 25 March 1998. The shape of the measured spectrum is compared with the expectation for solar 8B neutrinos. The comparison takes into account both kinematic and detector related effects in the measurement process. The spectral shape comparison between the observation and the expectation gives a χ2 of 25.3 with 15 degrees of freedom, corresponding to a 4.6% confidence level. copyright 1999 The American Physical Society

  13. Status of solar neutrino experiments

    A summary of the status of four solar neutrino experiments is presented. The Homestake 37Cl 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 71Ga 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

  14. Is There a Deficit of Solar Neutrinos?

    Manuel, O; Katragada, Aditya

    2004-01-01

    Measurements on the isotopic and elemental compositions of meteorites, planets, lunar samples, the solar wind, and solar flares since 1960 suggest that the standard solar model may be in error. A new solar model suggests that the observed number of solar neutrinos represents at least 87% of the number generated: There is little if any deficit of solar neutrinos.

  15. Solar Neutrino Measurements in Super-Kamiokande-IV

    Collaboration, Super-Kamiokande; :; Abe, K.; Haga, Y.; Hayato, Y.; Ikeda, M; Iyogi, K.; Kameda, J.; Kishimoto, Y.; Marti, Ll.; Miura, M.; Moriyama, S.; Nakahata, M.(University of Tokyo, Institute for Cosmic Ray Research, Kamioka Observatory, Kamioka, Japan); Nakajima, T.; Nakayama, S.

    2016-01-01

    Upgraded electronics, improved water system dynamics, better calibration and analysis techniques allowed Super-Kamiokande-IV to clearly observe very low-energy 8B solar neutrino interactions, with recoil electron kinetic energies as low as 3.49 MeV. Super-Kamiokande-IV data-taking began in September of 2008; this paper includes data until February 2014, a total livetime of 1664 days. The measured solar neutrino flux is (2.308+-0.020(stat.) + 0.039-0.040(syst.)) x 106/(cm2sec) assuming no osci...

  16. Solar nuclear energy generation and the chlorine solar neutrino experiment

    Haubold, H. J.; Mathai, A. M.

    1994-01-01

    The study of solar neutrinos may provide important insights into the physics of the central region of the Sun. Four solar neutrino experiments have confirmed the solar neutrino problem but do not clearly indicate whether solar physics, nuclear physics, or neutrino physics have to be improved to solve it. Nonlinear relations among the different neutrino fluxes are imposed by two coupled systems of differential equations governing the internal structure and time evolution of the Sun. We assume ...

  17. Solar photons, phonons and neutrinos

    Chitre, S.M

    1998-06-01

    The inside of the Sun is not directly accessible to observations. Nonetheless, it is possible to construct a reasonable picture of its interior with the help of the theory of stellar structure along with the input physics describing a multitude of processes occurring inside the Sun. In order to check the validity of these theoretical models there have been valiant attempts to measure the flux of neutrinos generated in the Sun's energy-generating core. The solar neutrino event rates reported by all the experiments to date have been consistently lower than those predicted by standard solar models. There is now a complementary probe, furnished by the accurately measured helioseismic data which provides stringent constraints on the physical conditions prevailing inside the Sun. It turns out that the helioseismically inferred density and sound speed profiles throughout the Sun's internal layers are close to those obtained with a standard solar model. A cooler solar core is, therefore, not a viable solution to account for the deficit in the measured neutrino fluxes. This leads one to the unavoidable conclusion that the solution to the solar neutrino puzzle should be sought in the realm of particle physics.

  18. Solar neutrinos: Oscillations or No-oscillations?

    Smirnov, A Yu

    2016-01-01

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

  19. A Search For Matter Enhanced Neutrino Oscillations Through Measurements Of Day And Night Solar Neutrino Fluxes At The Sudbury Neutrino Observatory

    Miknaitis, K K

    2005-01-01

    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 t...

  20. Halo effective field theory constrains the solar 7Be + p → 8B + γ rate

    Xilin Zhang

    2015-12-01

    Full Text Available We report an improved low-energy extrapolation of the cross section for the process Be7(p,γB8, which determines the 8B neutrino flux from the Sun. Our extrapolant is derived from Halo Effective Field Theory (EFT at next-to-leading order. We apply Bayesian methods to determine the EFT parameters and the low-energy S-factor, using measured cross sections and scattering lengths as inputs. Asymptotic normalization coefficients of 8B are tightly constrained by existing radiative capture data, and contributions to the cross section beyond external direct capture are detected in the data at E<0.5 MeV. Most importantly, the S-factor at zero energy is constrained to be S(0=21.3±0.7 eVb, which is an uncertainty smaller by a factor of two than previously recommended. That recommendation was based on the full range for S(0 obtained among a discrete set of models judged to be reasonable. In contrast, Halo EFT subsumes all models into a controlled low-energy approximant, where they are characterized by nine parameters at next-to-leading order. These are fit to data, and marginalized over via Monte Carlo integration to produce the improved prediction for S(E.

  1. Solar Neutrino Measurements in Super-Kamiokande-IV

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

    2016-01-01

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

  2. Treating solar model uncertainties: A consistent statistical analysis of solar neutrino models and data

    We describe how to consistently incorporate solar model uncertainties, along with experimental errors and correlations, when analyzing solar neutrino data to derive confidence limits on parameter space for proposed solutions of the solar neutrino problem. Our work resolves ambiguities and inconsistencies in the previous literature. As an application of our methods we calculate the masses and mixing angles allowed by the current data for the proposed MSW solution using both Bayesian and frequentist methods, allowing purely for solar model flux variations, to compare with previous work. We also show that solutions which simply suppress the 8B solar neutrino flux are strongly disfavored and have a likelihood ratio of at most 10-8 compared to the best MSW solution. Finally, we consider the effects of including metal diffusion in the solar models and also discuss implications for future experiments

  3. Solar neutrino spectroscopy (before and after superkamiokande)

    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

  4. MSW effect and solar neutrino experiments

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

  5. Neutrinos do come from solar-fusion

    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).

  6. The asymmetry of solar neutrino fluxes

    For each solar neutrino run all data for more than two solar cycles (1970-1994) are separated on three zones in dependence on the helio-latitude. For each latitudinal zone the average solar electron neutrino flux and correlations with effective solar activity parameters for asymmetrical latitude belts are determined. The obtained results indicate that neutrino should have nonzero mass and nonzero magnetic moment

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

    Renshaw, A.; Abe, K.; Hayato, Y.; Iyogi, K.; Kameda, J.; Kishimoto, Y.; Miura, M.; Moriyama, S.; Nakahata, M.(University of Tokyo, Institute for Cosmic Ray Research, Kamioka Observatory, Kamioka, Japan); Nakano, Y.; Nakayama, S.; Sekiya, H.; Shiozawa, M; Suzuki, Y; TAKEDA, A

    2013-01-01

    We report an indication that the elastic scattering rate of solar $^8$B neutrinos with electrons in the Super-Kamiokande detector is larger when the neutrinos pass through the Earth during nighttime. We determine the day/night asymmetry, defined as the difference of the average day rate and average night rate divided by the average of those two rates, to be $(-3.2\\pm1.1(\\text{stat})\\pm0.5(\\text{syst}))\\%$, which deviates from zero by 2.7 $\\sigma$. Since the elastic scattering process is mostl...

  8. Solar neutrino with Borexino: results and perspectives

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

    2014-01-01

    Borexino is a unique detector able to perform measurement of solar neutrinos fluxes in the energy region around 1 MeV or below due to its low level of radioactive background. It was constructed at the LNGS underground laboratory with a goal of solar $^{7}$Be neutrino flux measurement with 5\\% precision. The goal has been successfully achieved marking the end of the first stage of the experiment. A number of other important measurements of solar neutrino fluxes have been performed during the first stage. Recently the collaboration conducted successful liquid scintillator repurification campaign aiming to reduce main contaminants in the sub-MeV energy range. With the new levels of radiopurity Borexino can improve existing and challenge a number of new measurements including: improvement of the results on the Solar and terrestrial neutrino fluxes measurements; measurement of pp and CNO solar neutrino fluxes; search for non-standard interactions of neutrino; study of the neutrino oscillations on the short baselin...

  9. A solar neutrino loophole: standard solar models

    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. (orig.)

  10. The Borexino solar neutrino experiment and its scintillator containment vessel

    Cadonati, Laura

    2001-05-01

    Thirty years ago, the first solar neutrino detector proved fusion reactions power the Sun. However, the total rate detected in this and all subsequent solar neutrino experiments is consistently two to three times lower than predicted by the Standard Solar Model. Current experiments seek to explain this ``solar neutrino puzzle'' through non-standard particle properties, like neutrino mass and flavor mixing, within the context of the MSW theory. The detection of the monoenergetic 7Be solar neutrino is the missing clue for the solution of the solar neutrino problem; this constitutes the main physics goal of Borexino, a real- time, high-statistics solar neutrino detector located under the Gran Sasso mountain, in Italy. In the first part of this thesis, I present a Monte Carlo study of the expected performance of Borexino, with simulations of the neutrino rate, the external y background and the α/β/γ activity in the scintillator. The Standard Solar Model predicts a solar neutrino rate of about 60 events/day in Borexino in the 0.25-0.8 MeV window, mostly due to 7Be neutrinos. Given the design scintillator radiopurity levels (10-16 g/g 238U and 232Th and 10-14 g/g K), Borexino will detect such a rate with a ~2.4% statistical error, after one year. In the MSW Small (Large) Angle scenario, the predicted rate of ~13 (33) events/day will be detected with 8% (4%) error. The sensitivity of Borexino to 8B and pp neutrinos and to a Galactic supernova event is also discussed. The second part of this dissertation is devoted to the liquid scintillator containment vessel, an 8.5 m diameter sphere built of bonded panels of 0.125 mm polymer film. Through an extensive materials testing program we have identified an amorphous nylon-6 film which meets all the critical requirements for the success of Borexino. I describe tests of tensile strength, measurements of 222Rn diffusion through thin nylon films and of optical clarity. I discuss how the materials' radiopurity and mechanical

  11. Solar neutrino physics: Sensitivity to light dark matter particles

    Lopes, Ilidio

    2013-01-01

    Neutrinos are produced in several neutrino nuclear reactions of the proton-proton chain and carbon-nitrogen-oxygen cycle that take place at different radius 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 8B neutrino fluxes, we find that non-annihilating dark matter particl...

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

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

    2013-01-01

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

  13. Solar neutrinos: a scientific puzzle

    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.)

  14. Variations in the Solar Neutrino Flux

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

    1987-08-02

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

  15. Oscillations of solar and atmospheric neutrinos

    Barbieri, R; Hall, L. J.; Smith, D.; A. Strumia; Weiner, N

    1998-01-01

    Motivated by recent results from SuperKamiokande, we study both solar and atmospheric neutrino fluxes in the context of oscillations of the three known neutrinos. We aim at a global view which identifies the various possibilities, rather than attempting the most accurate determination of the parameters of each scenario. For solar neutrinos we emphasise the importance of performing a general analysis, independent of any particular solar model and we consider the possibility that any one of the...

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

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

    2011-01-01

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

  17. Physics Potential of Solar Neutrino Experiments

    Balantekin, A. B.; Yuksel, H.

    2003-01-01

    We discuss the physics potential of the solar neutrino experiments i) To explore the parameter space of neutrino mass and mixings; ii) To probe the physics of the Sun; iii) To explore nuclear physics of the neutrino-target interactions. Examples are given for these three classes.

  18. Particle physics confronts the solar neutrino problem

    This review has four parts. In Part I, we describe the reactions that produce neutrinos in the sun and the expected flux of those neutrinos on the earth. We then discuss the detection of these neutrinos, and how the results obtained differ from the theoretical expectations, leading to what is known as the solar neutrino problem. In Part II, we show how neutrino oscillations can provide a solution to the solar neutrino problem. This includes vacuum oscillations, as well as matter enhanced oscillations. In Part III, we discuss the possibility of time variation of the neutrino flux and how a magnetic moment of the neutrino can solve the problem. WE also discuss particle physics models which can give rise to the required values of magnetic moments. In Part IV, we present some concluding remarks and outlook for the recent future

  19. John Bahcall and the Solar Neutrino Problem

    Bahcall, Neta

    2016-03-01

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

  20. Limits on CPT violation from solar neutrinos

    Diaz, Jorge S

    2016-01-01

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

  1. Solar neutrinos, helioseismology and the solar internal dynamics

    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 7Be 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 masses are

  2. Solar neutrino physics with Borexino I

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

    2012-01-01

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

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

    Giunti, C; Peña-Garay, C

    2000-01-01

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

  4. Variations in the solar neutrino flux

    Observations are reported from the chlorine solar neutrino detector in the Homestake Gold Mine, South Dakota, USA. They extend from 1970 to 1985 and yield an average neutrino capture rate of 2.1 +- 0.3 SNU. The results from 1977 to 1985 show an anti-correlation with the solar activity cycle, and an apparent increased rate during large solar flares. 18 refs., 2 figs

  5. Constraining neutrino magnetic moment with solar neutrino data

    Tortola, M A

    2003-01-01

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

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

    2005-01-01

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

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

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

    2015-01-01

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

  8. Do solar neutrinos constrain the electromagnetic properties of the neutrino?

    Friedland, Alexander

    2005-01-01

    It is of great interest whether the recent KamLAND bound on the flux of electron antineutrinos from the Sun constrains the electromagnetic properties of the neutrino. We examine the efficiency of the electron antineutrino production in the solar magnetic fields, assuming the neutrinos are Majorana particles with a relatively large transition moment. We consider fields both in the radiative and convective zones of the Sun, with physically plausible strengths, and take into account the recently...

  9. Neutrino Dipole Moments and Solar Experiments

    Picariello, M; Das, C R; Fernandez-Melgarejo,; Montanino, D; Pulido, J; Torrente-Lujan, E

    2009-01-01

    First we investigate the possibility of detecting solar antineutrinos with the KamLAND experiment. Then we analyze the first Borexino data release to constrain the neutrino magnetic moment. Finally we investigate the resonant spin flavour conversion of solar neutrinos to sterile ones, a mechanism which is added to the well known LMA one. In this last condition, we show that the data from all solar neutrino experiments except Borexino exhibit a clear preference for a sizable magnetic field. We argue that the solar neutrino experiments are capable of tracing the possible modulation of the solar magnetic field. In this way Borexino alone may play an essential role although experimental redundancy from other experiments will be most important.

  10. Solar neutrino enigma: a solution in view

    Up to now the number of detected solar neutrinos is three times lesser than the one theoretically calculated with the standard model. The possibility of new experiment is now studied to get new and decisive information of this number. Gallex experiment, a joint European project, is going on. It will use 30 tons of gallium as neutrino target

  11. Interactions Between Solar Neutrinos and Solar Magnetic Fields

    Oakley, D. S.; Snodgrass, Herschel B.

    1996-01-01

    We attempt to correlate all of the available solar-neutrino capture-rate data with the strong magnetic fields these neutrinos encounter in the solar interior along their Earth-bound path. We approximate these fields using the (photospheric, magnetograph-measured) surface magnetic flux from central latitude bands, time delayed to proxy the solar interior. Our strongest evidence for anticorrelation is for magnetic fields within the central $\\pm 5^{0}$ solar-latitude band that have been delayed ...

  12. Solar-neutrino results from SAGE

    The solar-neutrino-capture rate measured by the Russian-American Gallium Experiment on metallic gallium during the period from January 1990 to December 1997 is (67.2-7.0-3.0+7.2+3.5) SNU, where the uncertainties are statistical and systematic, respectively. This result represents a 7σ depression in the neutrino flux in relation to the predicted standard-solar-model rates. The experimental procedures used and data analysis are presented

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

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

    2016-01-01

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

  14. Optical Calibration Of The Sudbury Neutrino Observatory And Determination Of The Boron-8 Solar Neutrino Flux In The Salt Phase

    Grant, D R

    2004-01-01

    An improved measurement of the 8B solar neutrino flux has been made at the Sudbury Neutrino Observatory (SNO). This measurement has an increased sensitivity to the neutral current reaction. This is due to an enhanced neutron capture efficiency, accomplished by adding salt, NaCl, to the heavy water in the detector. The data set analyzed in the salt phase consists of approximately 254 days of neutrino data. The data set has been analyzed using independently developed probability density functions (PDFs) in an extended maximum likelihood calculation. The final 8B model-constrained results of this analysis are given by the fluxes (in units of 106 neutrinos/(cm2s)): •FSunCC=1 .69±0.07stat +0.07- 0.08 syst •FSunNC=4.91±0.2 3stat +0.32-0.27 syst •FSumES=2.11 +0.29- 0.27 stat+0.13 -0.19syst These fluxes give a CC/NC ratio of 0.344 ± 0.021(stat) +0.07- 0.08 syst . The results clearly demonstrate that solar neutrinos are oscillating from one flavor to a...

  15. Solar neutrino analysis of Super-Kamiokande

    Sekiya, Hiroyuki

    2013-01-01

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

  16. Large Solar Neutrino Mixing and Radiative Neutrino Mechanism

    Kitabayashi, T; Kitabayashi, Teruyuki; Yasue, Masaki

    2002-01-01

    We find that the presence of a global $L_e-L_\\mu-L_\\tau$ ($\\equiv L^\\prime$) symmetry and an $S_2$ permutation symmetry for the $\\mu$- and $\\tau$-families supplemented by a discrete $Z_4$ symmetry naturally leads to almost maximal atmospheric neutrino mixing and large solar neutrino mixing, which arise, respectively, from type II seesaw mechanism initiated by an $S_2$-symmetric triplet Higgs scalar $s$ with $L^\\prime=2$ and from radiative mechanism of the Zee type initiated by two singly charged scalars, an $S_2$-symmetric $h^+$ with $L^\\prime=0$ and an $S_2$-antisymmetric $h^{\\prime +}$ with $L^\\prime=2$. The almost maximal mixing for atmospheric neutrinos is explained by the appearance of the democratic coupling of $s$ to neutrinos ensured by $S_2$ and $Z_4$ while the large mixing for solar neutrinos is explained by the similarity of $h^+$- and $h^{\\prime +}$-couplings described by $f^h_+\\sim f^h_-$ and $\\mu_+\\sim\\mu_-$, where $f^h_+$ ($f^h_-$) and $\\mu_+$ ($\\mu_-$) stand for $h^+$ ($h^{\\prime +}$)-coupling...

  17. Solar neutrino results in Super-Kamiokande-III

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

    2010-01-01

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

  18. Neutrino magnetic moment and the solar neutrino problem

    For a relativistic particle of mass m, energy E and anomalous magnetic moment μ, the spin-flip angle in a magnetic field B after a length L is φ=(2μBL)/hc((mc2)/E) in ultrarelativistic limit. Contrary to recent assertions, a magnetic moment of μ=10-10μO for the neutrino cannot solve the solar neutrino puzzle by spin-flip in a simple way. The reflection coefficient and other possible effects are also discussed. (author). 11 refs

  19. Probing the Sun's inner core using solar neutrinos: a new diagnostic method

    Lopes, Ilídio

    2013-01-01

    The electronic density in the Sun's inner core is inferred from the 8B, 7Be and pep neutrino flux measurements of the Super-Kamiokande, SNO and Borexino experiments. We have developed a new method in which we use the KamLAND detector determinations of the neutrino fundamental oscillation parameters: the mass difference and the vacuum oscillation angle. Our results suggest that the solar electronic density in the Sun's inner core (for a radius smaller than 10% of the solar radius) is well above the current prediction of the standard solar model, and by as much as 25%. A potential confirmation of these preliminary findings can be achieved when neutrino detectors are able to reduce the error of the electron-neutrino survival probability by a factor of 15.

  20. Constraining big bang lithium production with recent solar neutrino data

    Takács, Marcell P.; Bemmerer, Daniel; Szücs, Tamás; Zuber, Kai

    2015-06-01

    The 3He (α ,γ )7Be reaction affects not only the production of 7Li in big bang nucleosynthesis, but also the fluxes of 7Be and 8B neutrinos from the Sun. This double role is exploited here to constrain the former by the latter. A number of recent experiments on 3He α ,γ )7Be provide precise cross section data at E =0.5 - 1.0 MeV center-of-mass energies. However, there is a scarcity of precise data at big bang energies, 0.1-0.5 MeV, and below. This problem can be alleviated, based on precisely calibrated 7Be and 8B neutrino fluxes from the Sun that are now available, assuming the neutrino flavor oscillation framework to be correct. These fluxes and the standard solar model are used here to determine the 3He α ,γ )7Be astrophysical S -factor at the solar Gamow peak, S34ν(2 3-5+6 keV ) =0.548 ±0.054 keV b . This new data point is then included in a reevaluation of the 3He α ,γ )7Be S -factor at big bang energies, following an approach recently developed for this reaction in the context of solar fusion studies. The reevaluated S -factor curve is then used to redetermine the 3He α ,γ )7Be thermonuclear reaction rate at big bang energies. The predicted primordial lithium abundance is 7Li H =5.0 ×10-10 , far higher than the Spite plateau.

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

    Cadonati, L

    2001-01-01

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

  2. Prospects for cryogenic detection of solar neutrinos

    Several projects are underway aimed at developing techniques to detect low energy (Eν < 1 keV) neutrinos. They are based on cryogenic methods. The reasons why the study of solar neutrinos requires such techniques, the principles on which they are based and their present status are discussed. Especially, the crystal technique and the superfluid helium technique is considered. (author) 13 refs., 2 figs., 1 tab

  3. Analysis of solar models - neutrinos and oscillations

    The theory of stellar structure and evolution is used to calculate the properties of a variety of objects from red giants and supernova precursors to white dwarfs and neutron stars. Accurate tests of the theory in the context of these applications are generally not available. The sun as the nearest star provides a unique example of a star which can be subjected to a variety of precise tests not possible with remote stars. We will concentrate on two of these tests - solar neutrinos and solar oscillations - which currently indicate that there is something seriously wrong with our standard solar model. Although we do not yet known what the source of the error is, it is quite possible that the correction of this error will require some modification of the results of other applications of stellar structure theory. It now seems unlikely that the difficulty with the solar neutrino experiment lies in the experiment itself. The combination of the difficulty with the solar neutrino flux and the difficulty with the solar oscillation frequencies suggests that the solar neutrino problem is a failure of stellar structure theory rather than a failure of weak interaction theory, although this latter possibility cannot yet be firmly ruled out

  4. Testing the solar neutrino conversion with atmospheric neutrinos

    Neutrino oscillations with parameters Δm2 = (2-20).10-5 eV2, sin2 2θ>0.65, relevant for large mixing MSW solution of the solar neutrino problem can lead to an observable (up to 10-12%) excess of the e-like events in the sub-GeV atmospheric neutrino sample. The excess has a weak zenith angle dependence in the low energy part of the sample and strong zenith angle dependence in the high energy part. The excess rapidly decreases with energy of neutrinos, it is suppressed in the multi-GeV sample. These signatures allow one to disentangle the effect of oscillations due to solar Δm2 from other possible explanations of the excess. The up-down asymmetry of the excess may change the sign with energy being positive in the sub-GeV region and negative in the multi-GeV range. Predicted properties of the excess are in agreement with the SuperKamiokande data. (author)

  5. Everything under the Sun: A review of solar neutrinos

    Solar neutrinos offer a unique opportunity to study the interaction of neutrinos with matter, a sensitive search for potential new physics effects, and a probe of solar structure and solar system formation. This paper describes the broad physics program addressed by solar neutrino studies, presents the current suite of experiments programs, and describes several potential future detectors that could address the open questions in this field. This paper is a summary of a talk presented at the Neutrino 2014 conference in Boston

  6. Measurement of the Solar Neutrino Capture Rate by SAGE and Implications for Neutrino Oscillations in Vacuum

    The Russian-American solar neutrino experiment has measured the capture rate of neutrinos on metallic gallium in a radiochemical experiment at the Baksan Neutrino Observatory. Eight years of measurement give the result 67.2+7.2+3.5-7.0-3.0 solar neutrino units, where the uncertainties are statistical and systematic, respectively. The restrictions these results impose on vacuum neutrino oscillation parameters are given. (c) 1999 The American Physical Society

  7. Solar Neutrino Measurement at SK-III

    Yang, B S

    2009-01-01

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

  8. Solar neutrinos: Real-time experiments

    Totsuka, Yoji

    1993-04-01

    This report outlines the principle of real-time solar neutrino detection experiments by detecting electrons with suitable target material, via Charged-Current (CC) reaction using conventional counting techniques developed in high-energy physics. Only B-8 neutrinos can be detected by minimum detectable energy of several MeV. The MSW (Mikheyev, Smirnov, Wolfenstein) effect not only distorts the energy spectrum but also induces new type of neutrinos, i.e. mu-neutrinos or tau-neutrinos. These neutrinos do not participate in the CC reaction. Therefore real-time experiment is to be sensitive to Neutral Current (NC) reactions. It is a challenge to eliminate environment background as much as possible and to lower the minimum detectable energy to several 100 keV, which will enable observation of Be-7 neutrinos. Target particles of real-time experiments currently running and under construction or planning are electron, deuteron, or argon. The relevant reactions corresponding to CC reaction and some relevant comments on the following targets are described: (1) electron target; (2) deuteron target; and (3) argon target. On-going experiment and future experiments for real-time neutron detection are also outlined.

  9. New tests for neutrinos in low-energy solar experiments

    Pastor, S

    1999-01-01

    We show how future solar neutrino experiments in the low energy region can be used to test novel neutrino properties. Information on the Majorana nature or neutrino magnetic moments can be extracted from the observation of electron anti-neutrinos from the Sun and the measurement of an azimuthal asymmetry in the total number of events, respectively.

  10. Helioseismology, solar models and neutrino fluxes

    Castellani, V.; Degl'Innocenti, S.; Dziembowski, W. A.; Fiorentini, G.; Ricci, B.

    1997-01-01

    We present our results concerning a systematical analysis of helioseismic implications on solar structure and neutrino production. We find Y$_{ph}=0.238-0.259$, $R_b/R_\\odot=0.708-0.714$ and $\\rho_b=(0.185-0.199)$ gr/cm$^3$. In the interval $0.2

  11. Solar neutrino variations: a manifestation of nonzero neutrino mass and magnetic moment, and mixing

    Time variations of solar neutrino flux are investigated for more that two solar cycles (1970-1994). For each solar neutrino run n, the effective Earth's helio-latitude, the effective sunspots number, the effective latitude of sunspots distribution, and the effective surfaces of sunspots are determined. The correlation of solar electron neutrino fluxes with these parameters for different periods of solar activity are considered. It is found that correlation coefficients change the sign in different periods of solar activity. The obtained information indicate that neutrino should have nonzero mass and nonzero magnetic moment

  12. Solar neutrinos: proposal for a new test

    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 107 year lead-205 in old thallium minerals. Comments are solicited from those in all relevant disciplines

  13. Solar neutrinos: propsects for detection and implications

    From the viewpoint of particle physics, the sun provides us with a high intensity (approx. 1011/cm2sec) 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 107 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

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

    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 ν-e elastic scattering, while the νe flux measurement involves an inverse beta decay detection, such as 37Cl(νe, e-)37Ar. The interactions due to 7Be neutrinos must be separated FR-om those due to 8B neutrinos. A Cherenkov signal-triggered radiochemical detector is proposed that will allow a very precise determination of both the 8B and 7Be electron neutrino fluxes FR-om the Sun. The basic concept is to identify each 8B electron neutrino interaction in the detector and then sweep out the 37Ar atom produced by this 8B neutrino as soon as it is made. A set of photomultipler tubes can be used to detect the Ar atom production and immediately initiate its fast extraction. This can be described as single-atom extraction FR-om massive, multiton detectors and classification of these single atoms

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

    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 ...

  16. Turbulent diffusion and the solar neutrino problem

    This lecture presents a summary of the problem and includes the solutions found by Maeder and the author. The first part gives an outline of the structure of the Sun, especially the existence of a convective zone, and the different sources of energy, with predictions of the solar neutrino flux and earlier solutions of the solar neutrino problem. It is then shown how various kinds of instability existing inside rotating stars can generate a mild turbulence. A proof of the existence of this turbulence is looked for in the abundances of chemical elements at the surface of stars: abundances at variance with gravitational sorting; surface abundance of lithium and beryllium in the Sun; surface abundances of lithium in field stars; surface abundances of carbon isotopes in evolved stars. The last section shows that a turbulent diffusion coefficient Dsub(T) approx. equal to 0.1 Resub(critical), where Resub(critical) is the critical Reynolds number for which turbulence sets in, leads to a consistent solar model with a low neutrino flux. As a conclusion a comment is made on the gallium experiment, which can discriminate between the structural effects of the Sun and a possible neutrino oscillation. (orig.)

  17. Neutrinoless double beta decay, solar neutrinos and mass scales

    Osland, Per; Vigdel, Geir

    2001-01-01

    We obtain bounds for the neutrino masses by combining atmospheric and solar neutrino data with the phenomenology of neutrinoless double beta decay where hypothetical values of || are envisaged from future 0\

  18. Solar neutrino physics in the nineties

    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.

  19. Dark matter, neutrinos, and our solar system

    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...

  20. Report on the Brookhaven Solar Neutrino Experiment

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

    1976-09-22

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

  1. KamLAND Bounds on Solar Antineutrinos and neutrino transition magnetic moments

    Torrente-Lujan, E

    2003-01-01

    We investigate the possibility of detecting solar antineutrinos with the KamLAND experiment. These antineutrinos are predicted by spin-flavor oscillations at a significant rate even if this mechanism is not the leading solution to the SNP. The recent evidence from SNO shows that the solar flux could contain a residual component including sterile neutrinos and/or the antineutrinos of the active flavors. KamLAND is sensitive to antineutrinos originated from solar ${}^8$B neutrinos. From KamLAND negative results after 145 days of data taking, we obtain model independent limits on the total flux of solar antineutrinos $\\Phi({}^8 B)< 1.1-3.5\\times 10^4 cm^{-2} s^{-1}$, more than one order of magnitude smaller than existing limits,and on their appearance probability $P<0.15%$ (95% CL). Assuming a concrete model for antineutrino production by spin-flavor precession, this upper bound implies an upper limit on the product of the intrinsic neutrino magnetic moment and the value of the solar magnetic field $\\mu B&...

  2. Data analysis for solar neutrinos observed by water Cherenkov detectors⋆

    Koshio, Yusuke

    2016-04-01

    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.

  3. The Russian-American Gallium solar neutrino Experiment

    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 51Cr neutrino source irradiation to test the overall operation of the experiment is also presented

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

    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 81Br(nu,e-)81Kr to measure the flux of 7Be neutrinos from the sun. When 7Be decays by electron capture to make 7Li, a neutrino is emitted at 0.862 MeV and the flux of these on the earth is about 4 x 109 cm-2 s-1, according to the standard model. Therefore, an experiment based on 81Br(nu,e-)81Kr which is sensitive to these lower energy neutrinos would be of fundamental importance. To first order, the chlorine experiment detects the 8B neutrinos while bromine detects the much more abundant 7Be neutrino source. In practice, the proposed bromine experiment would be very similar to the chlorine radiochemical experiment, except that 81Kr with a half-life of 2 x 105 years cannot be counted by decay methods. With an experiment of about the same volume as the chlorine experiment (380 m3) filled with CH2Br2, the model predicts about 2 atoms of 81Kr per day. The bromine experiment depends entirely on the RIS method, implemented with pulsed lasers, for its success. 10 refs., 3 figs

  5. The neutrino magnetic moment and time variations of the solar neutrino flux

    The present status of the neutrino magnetic moment solutions of the solar neutrino problem is summarized. After a brief review of the basics of the neutrino spin and spin-flavor precession I discuss the experimental data and show how the neutrino resonant spin-flavor precession (RSFP) mechanism can naturally account for sizeable time variations in the Homestake signal and no observable time variations in the Kamiokande and gallium experiments. Fits of the existing data and predictions for the forthcoming solar neutrino experiments are also discussed. In the last section I summarize the objections to the RSFP mechanism that are frequently put forward and comment on them. (author). 69 refs, 3 figs

  6. Neutrino observations from the Sudbury Neutrino Observatory

    The Sudbury Neutrino Observatory (SNO) is a water imaging Cherenkov detector. Its usage of 1000 metric tons of D2O as target allows the SNO detector to make a solar-model independent test of the neutrino oscillation hypothesis by simultaneously measuring the solar νe flux and the total flux of all active neutrino species. Solar neutrinos from the decay of 8B 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 νe, the ES reaction also has a small sensitivity to νμ and ντ. In this paper, recent solar neutrino results from the SNO experiment are presented. It is demonstrated that the solar flux from 8B 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 νe flux deduced from the CC reaction rate in SNO differs from the Super-Kamiokande ES results by 3.3σ. This is evidence for an active neutrino component, in additional to νe, in the solar neutrino flux. These results also allow the first experimental determination of the total active 8B neutrino flux from the Sun, and is found to be in good agreement with solar model predictions

  7. Neutrino observations from the Sudbury Neutrino Observatory

    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.

  8. Neutrino Observations from the Sudbury Neutrino Observatory

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

    2001-09-24

    The Sudbury Neutrino Observatory (SNO) is a water imaging Cherenkov detector. Its usage of 1000 metric tons of D{sub 2}O as target allows the SNO detector to make a solar-model independent test of the neutrino oscillation hypothesis by simultaneously measuring the solar {nu}{sub e} flux and the total flux of all active neutrino species. Solar neutrinos from the decay of {sup 8}B have been detected at SNO by the charged-current (CC) interaction on the deuteron and by the elastic scattering (ES) of electrons. While the CC reaction is sensitive exclusively to {nu}{sub e}, the ES reaction also has a small sensitivity to {nu}{sub {mu}} and {nu}{sub {tau}}. In this paper, recent solar neutrino results from the SNO experiment are presented. It is demonstrated that the solar flux from {sup 8}B decay as measured from the ES reaction rate under the no-oscillation assumption is consistent with the high precision ES measurement by the Super-Kamiokande experiment. The {nu}{sub e} flux deduced from the CC reaction rate in SNO differs from the Super-Kamiokande ES results by 3.3{sigma}. This is evidence for an active neutrino component, in additional to {nu}{sub e}, in the solar neutrino flux. These results also allow the first experimental determination of the total active {sup 8}B neutrino flux from the Sun, and is found to be in good agreement with solar model predictions.

  9. Neutrino magnetic moments and low-energy solar neutrino-electron scattering experiments

    Pastor, S; Semikoz, V B; Valle, José W F

    1999-01-01

    The scattering of solar neutrinos on electrons is sensitive to the neutrino magnetic moments through an interference of electromagnetic and weak amplitudes in the cross section. We show that future low-energy solar neutrino experiments with good angular resolution can be sensitive to the resulting azimuthal asymmetries in event number and should provide useful information on non-standard neutrino properties such as magnetic moments. We compare asymmetries expected at HELLAZ (mainly pp neutrinos) with those at the Kamiokande and Super-Kamiokande experiments (Boron neutrinos), both for the case of Dirac and Majorana neutrinos and discuss the advantages of low energies. Potentially interesting information on the solar magnetic fields may be accessible

  10. Measurement of the solar neutrino capture rate by SAGE and implications for neutrino oscillations in vacuum

    Abdurashitov, J N; Cherry, M L; Cleveland, B T; Davis, R; Elliott, S R; Gavrin, V N; Girin, S V; Gorbachev, V V; Ibragimova, T V; Kalikhov, A V; Knodel, T V; Lande, K; Mirmov, I N; Nico, J S; Shikhin, A A; Teasdale, W A; Veretenkin, E P; Vermul, V M; Wark, D L; Wildenhain, P S; Yants, V E; Zatsepin, G T; Khairnasov, N G; Wilkerson, J F

    1999-01-01

    The Russian-American solar neutrino experiment has measured the capture rate of neutrinos on metallic gallium in a radiochemical experiment at the Baksan Neutrino Observatory. Eight years of measurement give the result 67.2 (+7.2,-7.0) (+3.5,-3.0) SNU, where the uncertainties are statistical and systematic, respectively. The restrictions these results impose on vacuum neutrino oscillation parameters are given.

  11. Towards the resolution of the solar neutrino problem

    Friedland, Alexander

    2000-08-29

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

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

    Debasish Majumdar

    2002-01-01

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

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

    Hartman, Nicole; Sekula, Stephen

    2016-01-01

    As neutrinos become a significant background for projected dark matter experiments, the community will become concerned with determining if events counted in a dark matter experiment are good dark matter candidates or low-energy neutrinos from astrophysical sources. We investigate the feasibility of using neutrino-electron scattering in a terrestrial detector medium as a means to determine the flight direction of the original, low-energy solar neutrino.Using leading-order weak interactions in...

  14. Possible explanation of the solar-neutrino puzzle

    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.

  15. Limits on C P T violation from solar neutrinos

    Díaz, Jorge S.; Schwetz, Thomas

    2016-05-01

    Violations of C P T invariance can induce neutrino-to-antineutrino transitions. We study this effect for solar neutrinos and use the upper bound on the solar neutrino-to-antineutrino transition probability from the KamLAND experiment to constrain C P T -symmetry-violating coefficients of the general Standard-Model Extension. The long propagation distance from the Sun to the Earth allows us to improve existing limits by factors ranging from about a thousand to 1011 .

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

    David G. Cerdeño; Fairbairn, Malcolm; Jubb, Thomas; Machado, Pedro A. N.; Vincent, Aaron C.; Boehm, Céline

    2016-01-01

    The next generation of dark matter direct detection experiments will be sensitive to both coherent neutrino-nucleus and neutrino-electron scattering. This will enable them to explore aspects of solar physics, perform the lowest energy measurement of the weak angle to date, and probe contributions from new theories with light mediators. In this article, we compute the projected nuclear and electron recoil rates expected in several dark matter direct detection experiments due to solar neutrinos...

  17. Neutrino oscillations and uncertainty in the solar model

    Dearborn, D. S.; Fuller, G. M.

    1989-06-01

    The Mikheyev-Smirnov-Wolfenstein (MSW) resonant neutrino oscillation mechanism is investigated for the Sun using a detailed numerical solar model and a modified version of the Parke-Walker technique for following the neutrino phases through the oscillation resonance. We present overall solar-neutrino spectra and the associated expected neutrino count rates for the 37Cl, 71Ga, and Kamiokande detectors for ranges of masses and vacuum mixing angles for two neutrino species. We also investigate the effects of uncertainties in the solar model. In particular, we examine the effect of opacity changes on the expected solar-neutrino spectrum and resulting parameter space for the MSW mechanism. We find that plausible uncertainties in the standard solar model, and in particular the opacity, translate into significant expansion in the constraints on neutrino masses and vacuum mixing angles from neutrino experiments. It is shown, however, that forthcoming results from the Kamiokande solar-neutrino experiment could put stringent constraints on even the expanded MSW parameter space.

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

    Suzuki, Y

    2001-01-01

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

  19. Solar neutrino and 51Cr results from SAGE

    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 71Ga 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 71Ge by an intense 51Cr 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.)

  20. Theoretical Implications of the Combined Solar Neutrino Observations

    Bludman, S.A.; Hata, N; Kennedy, D. C.; Langacker, P. G.

    1992-01-01

    Constraints on the core temperature of the Sun and on neutrino-oscillation parameters are obtained by comparing the combined Homestake, Kamiokande, SAGE and GALLEX solar neutrino data with Standard Solar Models (SSM) and with non-standard solar models parameterized by a phenomenological central temperature ($T_c$). If the Sun is 2\\% cooler or 3\\% warmer than predicted by SSMs, the MSW parameters we determine are consistent with different grand unified theories.

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

    Liu, Jian-Miin

    2001-01-01

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

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

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

    2003-01-01

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

  3. Democratic Approach To Atmospheric And Solar Neutrino Oscillations

    Shafi, Qaisar; Shafi, Qaisar; Tavartkiladze, Zurab

    2002-01-01

    Working with a U(1) flavor symmetry, we show how the hierarchical structure in the charged fermion sector and a democratic approach for neutrinos that yields large solar and atmospheric neutrino mixings can be simultaneously realized in the MSSM framework. However, in SU(5) due to the unified multiplets we encounter difficulties. Namely, democracy for the neutrinos leads to a wrong hierarchical pattern for charged fermion masses and mixings. We discuss how this is overcome in flipped SU(5).

  4. 7Be Solar Neutrino Measurement with KamLAND

    The KamLAND Collaboration; 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.

    2014-05-26

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

  5. 7Be Solar Neutrino Measurement with KamLAND

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

    2014-01-01

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

  6. The Role of Solar Neutrinos in the Jupiter

    Burov, Valery,; Hwang, W-Y. Pauchy

    2008-01-01

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

  7. The Role of Solar Neutrinos in the Jupiter

    Burov, Valery

    2008-01-01

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

  8. The solar LMA neutrino oscillation solution in the Zee model

    Balaji, K R S; Schwetz, T

    2001-01-01

    We examine the neutrino mass matrix in the version of Zee model where both Higgs doublets couple to the leptons. We show that in this case one can accommodate the large mixing angle (LMA) MSW solution of the solar neutrino problem, while avoiding maximal solar mixing and conflicts with constraints on lepton family number-violating interactions. In the simplified scenario we consider, we have the neutrino mass spectrum characterized by $m_1 \\simeq m_2 \\simeq \\sqrt{\\Delta m^2_\\mathrm{atm}}/\\sin 2\\theta$ and $m_3/m_1 \\simeq \\cos 2\\theta$, where $\\theta$ is the solar mixing angle.

  9. Solving Solar Neutrino Puzzle via LMA MSW Conversion

    2005-01-01

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

  10. Matter-enhanced neutrino spin rotation and the solar-neutrino problem

    It is shown that in the presence of matter there may occur resonant amplification of the flavor-changing neutrino spin rotation in transverse magnetic fields, which is roughly analogous to the Mikheyev-Smirnov-Wolfenstein (MSW) effect in neutrino oscillations. This may result in a strong reduction of the solar neutrino flux, as well as in the anticorrelation between the observed flux and the sun-spot number. The effect can, in principle, be distinguished from the MSW effect, as well as from the flavor-conserving neutrino spin procession

  11. The Nuclear Physics of Solar and Supernova Neutrino Detection

    Haxton, W. C.

    1999-01-01

    This talk provides a basic introduction for students interested in the responses of detectors to solar, supernova, and other low-energy neutrino sources. Some of the nuclear physics is then applied in a discussion of nucleosynthesis within a Type II supernova, including the r-process and the neutrino process.

  12. Theoretical introduction to the 37Cl solar neutrino experiment

    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 37Cl experiment

  13. Round table discussion of future Solar Neutrino Program

    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

  14. Seasonal Dependence in the Solar Neutrino Flux

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

    1999-01-01

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

  15. On the Study of Solar Flares with Neutrino Observatories

    ,

    2016-01-01

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

  16. Proceedings of the first workshop on solar neutrino detection

    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)

  17. New measurement of 8B Coulomb dissociation and E2 component

    The Coulomb dissociation of 8B in the field of 208Pb was studied at around 50 MeV/u incident energy. The astrophysical S-factors for the 7Be(p,γ)8B reaction, a key of the solar neutrino production, were deduced. Possible mixture of the E2 components are expected to be small based on our measurement of angular distribution in a wide range. This supports our earlier analysis assuming pure E1 transitions. (orig.)

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

    Cerdeño, David G.; Fairbairn, Malcolm; Jubb, Thomas; Machado, Pedro A. N.; Vincent, Aaron C.; Bœhm, Céline

    2016-01-01

    The next generation of dark matter direct detection experiments will be sensitive to both coherent neutrino-nucleus and neutrino-electron scattering. This will enable them to explore aspects of solar physics, perform the lowest energy measurement of the weak angle sin2θWto date, and probe contributions from new theories with light mediators. In this article, we compute the projected nuclear and electron recoil rates expected in several dark matter direct detection experiments due to solar neu...

  19. Bulk GaAs as a solar neutrino detector

    A GaAs detector may offer the unique possibility to independently study neutrino properties and solar physics. The ability to measure the flux of p-p, 7Be and pep solar neutrinos would allow one to approach a solution of the 'solar neutrino problem', i.e. the explanation of the significant deficit in observed capture rate of solar neutrinos. A large GaAs solar neutrino detector would allow to measure parameters for possible Mikheyev-Smirnov-Wolfenstein neutrino oscillations with unprecedented precision. A model-independent test for sterile neutrinos is also possible. A direct measurement of the temperature profile of the Sun center appears feasible. A GaAs detector would also provide the ability to observe neutral current interactions in addition to addressing a wide range of other interesting physics. In order to measure the p-p, pep and 7Be neutrinos a detector is required with low threshold (< 350 keV), good energy resolution (< 2 keV) and low background. A GaAs solid-state detector could meet the listed requirements. A large GaAs detector would be composed of approximately 40,000 intrinsic GaAs crystals, each weighting 3.2 kg. Such a detector would have a mass of 125 ton and would contain 60 ton of Ga occupying a volume of roughly 3 m on one side. Previous efforts by many groups have resulted in producing very small detectors with reasonably good resolution. However, it has thus far proved impossible to make large detectors with good resolution. Thus, a solar neutrino detector such as the one described above is obviously very ambitious, but the scientific motivation is sufficiently high that we have begun a research and development program with the goal of determining the technical feasibility of constructing large GaAs crystals with the requisite electronic properties to serve as particle detectors

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

    Hartman, Nicole

    2016-01-01

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

  1. KamLAND: A reactor neutrino experiment testing the solar neutrino anomaly

    KamLAND is a 1000 ton liquid scintillation detector currently under construction in the Kamioka mine in Japan. This underground site, with its large overburden of 2700 mw.e., is conveniently located at a distance of 150-210 km to several Japanese nuclear power stations. A measurement of the flux and energy spectrum of the electron anti-neutrinos, emitted by those reactors, will allow us to test the Large Mixing Angle Solution of the solar neutrino anomaly by performing a disappearance search for anti-neutrino oscillations. We will hence, for the first time, provide a completely solar model independent test of this particle physics solution of the solar neutrino problem. Data taking is expected to commence in 2001

  2. The Borexino Solar Neutrino Experiment: Scintillator purification and surface contamination

    Leung, Michael

    The Borexino Solar Neutrino Experiment will observe the monoenergetic (862 keV) 7Be neutrinos, produced in the solar reaction 7Be+e- →7 Li+nue. These neutrinos are the second most abundant species of solar neutrinos, with an expected flux at earth of 5 x 109/cm2/s. Using nu - e scattering in an aromatic liquid scintillator, Borexino will make the first real time measurement of the solar neutrino flux at energies less than 1 MeV. In addition to checking Standard Solar Model and neutrino oscillation predictions at low energies, Borexino will test the MSW vacuum-matter transition, luminosity constraint, and non-standard theories such as mass varying neutrinos. The Borexino detector will also be sensitive to supernova neutrinos, geoneutrinos, reactor neutrinos, and pep solar neutrinos. The pep measurement will tightly constrain the primary pp solar neutrino flux whose energy is below the Borexino threshold. With an expected rate of 35 events per day from solar 7Be neutrinos, the maximum tolerable background rate is one count per day. Removal of radioactive isotopes from the liquid scintillator is essential for the experiment's success and will be achieved with purification techniques including filtration, distillation, water extraction, nitrogen stripping, and silica gel adsorption. Results from small-scale purification efficiency tests are presented. Water extraction showed moderate but inadequate removal of 210Po which is a dominant background. Distillation reduced 210Po by a factor of more than 500. Online purification involves cycling over 300 m3 of scintillator from the detector though the purification plants. Flow patterns within the detector that influence the purification efficiency were determined with numerical simulations. Poor flow in the prototype Counting Test Facility showed effectively stagnant volumes within the detector. These are not present in the larger Borexino detector. Surface contamination in Borexino arises primarily from contact with

  3. Chemical aspects of the gallex solar neutrino experiment

    The Gallex solar neutrino experiment, described in the previous paper, will utilize 30 tons of gallium, in the form of an aqueous solution of 8M GaCl3, as a radiochemical detector of solar neutrinos. The capture of a neutrino by 71Ga will initiate inverse β decay and produce 71Ge, which decays with an 11.2-day half-life. This talk will focus on the chemical steps that have been devised to separate the minute amounts of product germanium from the gallium solution and to convert the 71Ge to a chemical form suitable for inclusion in a proportional counter. Questions concerning the specification and determination of impurity levels in the GaCl3 solution, so as to preclude reactions on impurities that would mimic the capture of a solar neutrino by 71Ga, will also be discussed

  4. Boron neutrino flux and resonant conversion of solar neutrinos

    In view of large uncertainties in the prediction of the boron neutrino flux from the Sun we consider the magnitude of this flux, ΦB, as a parameter to be found from experiment. A consistent description of the data in terms of neutrino resonance conversion admits ΦB/Φ0B=0.4 - 2.5 in small mixing domain and ΦB/Φ0B=1 - 3 in large mixing domain, (here φ0B ≡ 5.7 · 106 cm-2s-1 is the flux in the reference SSM). Variations of the flux within these intervals enlarge the allowed region of mixing angles to sin22θ=(0.06 -2) · 10-2 and sin22θ=0.2 - 0.9 correspondingly. If the value of ΦB is about that measured by Kamiokande, the data fix the region Δm2 ∼ (4-9) · 10-6 eV2 and sin2 2θ ∼ (0.6 - 2) · 10-3 (''very small mixing solution''). We comment on the possibility to measure the neutrino parameters and the original boron neutrino flux in future experiments. (author). 31 refs, 3 figs, 2 tabs

  5. The Sudbury Neutrino Observatory

    Bellerive, A; McDonald, A B; Noble, A J; Poon, A W P

    2016-01-01

    This review paper provides a summary of the published results of the Sudbury Neutrino Observatory (SNO) experiment that was carried out by an international scientific collaboration with data collected during the period from 1999 to 2006. By using heavy water as a detection medium, the SNO experiment demonstrated clearly that solar electron neutrinos from $^8$B decay in the solar core change into other active neutrino flavors in transit to Earth. The reaction on deuterium that has equal sensitivity to all active neutrino flavors also provides a very accurate measure of the initial solar flux for comparison with solar models. This review summarizes the results from three phases of solar neutrino detection as well as other physics results obtained from analyses of the SNO data.

  6. The Sudbury Neutrino Observatory

    Bellerive, A.; Klein, J. R.; McDonald, A. B.; Noble, A. J.; Poon, A. W. P.

    2016-07-01

    This review paper provides a summary of the published results of the Sudbury Neutrino Observatory (SNO) experiment that was carried out by an international scientific collaboration with data collected during the period from 1999 to 2006. By using heavy water as a detection medium, the SNO experiment demonstrated clearly that solar electron neutrinos from 8B decay in the solar core change into other active neutrino flavors in transit to Earth. The reaction on deuterium that has equal sensitivity to all active neutrino flavors also provides a very accurate measure of the initial solar flux for comparison with solar models. This review summarizes the results from three phases of solar neutrino detection as well as other physics results obtained from analyses of the SNO data.

  7. Electromagnetic properties of neutrino and possible semiannual variation cycle of the solar neutrino flux

    The existence of neutrino magnetic moment μν or(and) electric dipole moment εν of the order of 10-10 μB would give rise to variations of the observed solar neutrino flux correlated with the magnetic activity of the Sun. In this case besides the overall 11-year period there should also exist in the years of maximal activity a semiannual variation cycle of the observed flux of boron neutrinos. The latter variations are caused by the existence of the equatorial ''slit'' in the toroidal magnetic field of the Sun and by inclination of the ecliptic to the solar equator. Neutrino flavor changing electromagnetic moments of the type of μν and εν and possibilities of studying them with a large liquid argon νe-scattering detector are discussed

  8. The strange disappearance of solar neutrinos

    This article recalls the different works and studies performed on the neutrino: hypothesis of its existence, detection of few of these particles, development of a model predicting the number of neutrinos emitted by the sun at different energy levels (Bahcall model, 1964), and design of a particle trap. This last experiment gave surprising results: two thirds of the expected neutrinos were missing. The author recalls the different explanations given for these results, and evokes new models which emerged after that, notably the assumption of a possible existence of different forms of neutrinos. In the 1990's, a new sensor actually demonstrated the transformation of neutrinos after they have crossed the Earth. Then, summing the different types of neutrinos (muon, electronic, tau), gave the result predicted by the Bahcall model

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

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

    2016-01-01

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

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

    The analysis of the resonant spin-flavour (RSF) solutions to the solar neutrino problem in the framework of simplest analytic solutions to the solar magneto-hydrodynamics (MHD) equations is presented. We performed the global fit of the recent solar neutrino data, including event rates as well as 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 to disentangle the MHD-RSF scenario from other scenarios

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

    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

  12. Leptonic Generation Mixing, Noncommutative Geometry and Solar Neutrino Fluxes

    Häussling, R; Scheck, F

    1998-01-01

    Triangular mass matrices for neutrinos and their charged partners contain full information on neutrino mixing in a most concise form. Although the scheme is general and model independent, triangular matrices are typical for reducible but indecomposable representations of graded Lie algebras which, in turn, are characteristic for the standard model in noncommutative geometry. The mixing matrix responsible for neutrino oscillations is worked out analytically for two and three lepton families. The example of two families fixes the mixing angle to just about what is required by the Mikheyev-Smirnov-Wolfenstein resonance oscillation of solar neutrinos. In the case of three families we classify all physically plausible choices for the neutrino mass matrix and derive interesting bounds on some of the moduli of the mixing matrix.

  13. Is right-handed neutrino degeneracy compatible with the solar and atmospheric neutrino data?

    Felipe, R G

    2001-01-01

    In light of the recent solar and atmospheric neutrino data, we investigate the possibility of having an exactly degenerate spectrum for heavy right-handed Majorana neutrinos at the grand unification scale. The analysis is performed in the context of the minimal supersymmetric standard model with unbroken R-parity and extended with three heavy Majorana neutrino fields in order to implement the seesaw mechanism. In the absence of a Dirac-type leptonic mixing, the only source of lepton flavour violation is the right-handed neutrino sector. Inspired by GUT-motivated relations among the quark, charged-lepton and Dirac neutrino Yukawa coupling matrices, and after the inclusion of the radiative effects, we determine the effective neutrino mass matrix at the electroweak scale. Using then the latest global analyses of the solar and atmospheric data at 99% C.L., we conclude that, within this framework, the only solar solutions compatible with the experimental data are the LOW and LMA solutions, being the latter the mos...

  14. Measurement of the solar neutrino capture rate in Sage

    Combined analysis of the data of 92 runs of SAGE during the 12-year period January 1990 through December 2001 gives a capture rate of solar neutrinos with energy more than 233 keV of 70.9-5.2+5.3 (stat.) -3.2+3.7 (syst.) SNU. This represents only 55% of the predicted standard solar model rate of ∼130 SNU. The results of individual runs as well as the results of combined analysis of all runs during yearly, monthly, and bimonthly periods are presented. No compelling evidence for temporal variations is observed. By an analysis of the SAGE results combined with those from all other solar neutrino experiments, we make the first estimate of the electron neutrino pp flux that reaches the Earth to be (4.6 ± 1.2) x 1010/(cm2 s). Assuming that neutrinos oscillate to active flavors the pp neutrino flux emitted in the solar fusion reaction is approximately (7.6 ± 2.0) x 1010/(cm2 s), in agreement with the standard solar model calculation of (5.95 ± 0.06) x 1010/(cm2 s)

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

    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

  16. Measurements of the Solar Neutrino Flux from Super-Kamiokande close-quote s First 300 Days

    The first results of the solar neutrino flux measurement from Super-Kamiokande are presented. The results shown here are obtained from data taken between 31 May 1996, and 23 June 1997. Using our measurement of recoil electrons with energies above 6.5thinspthinspMeV, we infer the total flux of 8B solar neutrinos to be 2.42±0.06(stat)+0.10-0.07(syst)x106 thinspcm-2thinsp s-1 . This result is consistent with the Kamiokande measurement and is 36% of the flux predicted by the BP95 solar model. The flux is also measured in 1.5 month subsets and shown to be consistent with a constant rate. copyright 1998 The American Physical Society

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

    Bellini, G.; Benziger, J.; Bick, D.; Bonetti, S.; Bonfini, G.; Bravo, D.; Avanzini, M.; Caccianiga, B.; Cadonati, L.; F. Calaprice; Carraro, C; Cavalcante, P.; Chavarria, A.(Kavli Institute, Enrico Fermi Institute, Dept. of Physics, University of Chicago, Chicago, IL, 60637, USA); Chepurnov, A.; D. D’Angelo

    2011-01-01

    We observed, for the first time, solar neutrinos in the 1.0-1.5 MeV energy range. We measured the rate of pep solar neutrino interactions in Borexino to be [3.1+-0.6(stat)+-0.3(syst)] counts/(day x 100 ton) and provided a constraint on the CNO solar neutrino interaction rate of

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

    YANG Ping; LIU Qiu-Yu

    2009-01-01

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

  19. The Baksan gallium solar neutrino experiment

    Gavrin, V.N.; Abazov, A.I.; Abdurashitov, D.N.; Anosov, O.L.; Danshin, S.N.; Eroshkina, L.A.; Faizov, E.L.; Gayevsky, V.I.; Girin, S.V.; Kalikhov, A.V.; Knodel, T.V.; Knyshenko, I.I.; Kornoukhov, V.N.; Mezentseva, S.A.; Mirmov, I.N.; Ostrinsky, A.I.; Petukhov, V.V.; Pshukov, A.M.; Revzin, N.Y.; Shikhin, A.A.; Slusareva, Y.D.; Tikhonov, A.A.; Timofeev, P.V.; Veretenkin, E.P.; Vermul, V.M.; Yantz, V.E.; Zakharov, Yu.I.; Zatsepin, G.T.; Zhandarov, V.L. (AN SSSR, Moscow (USSR). Inst. Yadernykh Issledovanij); Bowles, T.J.; Cleveland, B.T.; Elliott, S.R.; O' Brien, S.R.; Wark, D.L.; Wilkerson, J.F. (Los Alamos National Lab., NM (USA)); Davis, R. Jr.; Lande, K. (Pennsylvania Univ., Philadelphia (USA)); Cherry, M.L. (Louisiana State Univ., Baton Rouge (USA)); Kouzes, R.T. (Princeton Univ., NJ (USA)); SAGE Collaboration

    1990-08-01

    A radiochemical {sup 71}Ga-{sup 71}Ge experiment to determine the integral flux of neutrinos from the sun has been constructed at the Baksan Neutrino Observatory in the USSR. Measurements have begun with 30 tonnes of gallium. An additional 30 tonnes of gallium are being installed so as to perform the full experiment with a 60-tonne target. The motivation, experiment procedures, and present status of this experiment are described. (orig.).

  20. Solar neutrino measurement with radiochemical gallium detector (GALLEX)

    von Ammon, Reinhard

    1994-04-01

    The GALLEX experiment for the detection of solar neutrinos by means of a radiochemical gallium detector is operated by groups from Italy, France, Germany, Israel and the USA in the Gran Sasso underground laboratory (LNGS) near L'Aquila (Italy). It consists of (1) the technical scale tank made of glass fiber reinforced polyester fabric containing 101 metric tons (54 cu m) of a highly concentrated (8 moles per liter) GaCl3 solution; (2) a gas sparging system for desorption of GeCl4 which has been formed by interaction of the neutrinos with gallium according to Ga-71 + nue yields Ge-71 + e(-) and by addition of ca. 1 mg of a stable Ge isotope; (3) the absorption columns for concentration of GeCl4 into a volume of 1 l of water; (4) the laboratory scale apparatus for conversion of GeCl4 to GeH4 and mixing with the counting gas Xe; (5) the counter filling station, and (6) the low level proportional counters. Contributions of possible side reactions which have to be corrected for, e.g. by cosmic muons, fast neutrons and alpha-emitters are discussed, as well as the purification of the target solution from long-lived ( t1/2 = 271 d) cosmogenic Ge-68. A first preliminary result after one year of solar neutrino measurement is presented. This constitutes the first direct measurement of the basic proton-proton fusion reaction in the core of the sun. This result, appreciably below the predictions of the standard solar model (SSM) (132 Solar Neutrino Units (SNU)) can be interpreted, together with the results of the chlori ne and KAMIOKANDE experiments either by astrophysics or by neutrino oscillations (Mikheyev-Smirnov-Wolfenstein (MSW) effect). The solar neutrino measurements are continuing and a calibration experiment with a Cr-51 source is in preparation.

  1. New measurement and analysis of the $^{7}Be(p,\\gamma) ^{8}B$ cross section

    Hammache, F; Aguer, P; Angulo, C; Barhoumi, S; Brillard, L; Chemin, J F; Claverie, G; Coc, A; Hussonnois, M; Jacotin, M; Kiener, J; Lefebvre, A; Scheurer, J N; Thibaud, J P; Virassamynaïken, E

    1998-01-01

    Cross sections for the 7Be(p,gamma)8B reaction have been measured for E_c.m.= 0.35-1.4 MeV using radioactive 7Be targets. Two independent measurements carried out with different beam conditions, different targets and detectors are in excellent agreement. A statistical comparison of these measurements with previous results leads to a restricted set of consistent data. The deduced zero-energy S-factor S(0) is found to be 15-20% smaller than the previously recommended value. This implies a 8B solar neutrino flux lower than previously predicted in various standard solar models.

  2. A few comments after the charged current measurement at the Sudbury Neutrino Observatory

    Fiorentini, G.; Villante, F. L.; Ricci, B.

    2001-01-01

    The comparison of the SNO charged current result with the solar neutrino signal measured by Super-Kamiokande has provided, for the first time, the evidence of a non electron flavour active neutrino component in the solar flux. We remark here that this evidence can be obtained in a model independent way, i.e. without any assumpion about solar models, about the energy dependence of the neutrino oscillation probability and about the presence of sterile neutrinos. Furthermore, from the 8B neutrin...

  3. New ideas on the detection of low energy solar neutrinos

    115In provides an extremely interesting target for real time solar neutrino detection [1]. Its use was proposed by Raghavan [2], based on the reaction: ν(E>128keV) + 115In→115Sn** + e-(Eν-128keV) where the 115Sn** decays to the ground state of 115Sn with a lifetime of 3.3 μS emitting two γ rays (497 keV and 116 keV)[3]. The delayed coincidence should provide a specific signature of solar neutrino events, sharp enough to overcome background problems related to 115In β radioactivity. Real time detection of solar neutrinos with 115In has been proposed by several techniques [4]. We discuss here the possibility of performing such an experiment, focusing on superconducting granules and special scintillators. The concept of 'localized micro-avalanche' should introduce crucial improvements in superheated superconducting granules (SSG) devices and, eventually, make feasible a 4 ton In solar neutrino experiment. The possible use of dedicated scintillating crystals of In compounds is also dealt with, as feasibility studies are under way

  4. The scintillator solvent procurement for the Borexino solar neutrino detector

    This paper describes the procurement and the production quality control system of Pseudocumene, the scintillator solvent of the solar neutrino detector Borexino at the Laboratorio Nazionale del Gran Sasso (Italy). This material constitutes about 99.9% of the scintillator total mass, therefore being the most critical element for the radiopurity of the detector.

  5. Solar Neutrinos with Magnetic Moment Rates and Global Analysis

    Pulido, J

    2002-01-01

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

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

    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 7Be 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 11C. 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 11C is mostly produced under the release of a free neutron, 11C can be tagged with a threefold coincidence (TFC) consisting of the muon signal, the neutron capture and the subsequent 11C decay. By optimizing the TFC method and other rejection techniques, a 11C 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 208Tl 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 228Th source was produced and an external calibration was carried out for the first time. The obtained calibration data and the achieved 11C rejection efficiency will allow for the direct detection of solar pep and possibly also CNO neutrinos with Borexino. (orig.)

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

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

    2006-01-01

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

  8. Neutrino signals from electroweak bremsstrahlung in solar WIMP annihilation

    Bell, Nicole F.; Brennan, Amelia J.; Jacques, Thomas D., E-mail: n.bell@unimelb.edu.au, E-mail: a.brennan@pgrad.unimelb.edu.au, E-mail: thomas.jacques@asu.edu [ARC Centre of Excellence for Particle Physics at the Terascale, School of Physics, The University of Melbourne, Victoria 3010 (Australia)

    2012-10-01

    Bremsstrahlung of W and Z gauge bosons, or photons, can be an important dark matter annihilation channel. In many popular models in which the annihilation to a pair of light fermions is helicity suppressed, these bremsstrahlung processes can lift the suppression and thus become the dominant annihilation channels. The resulting dark matter annihilation products contain a large, energetic, neutrino component. We consider solar WIMP annihilation in the case where electroweak bremsstrahlung dominates, and calculate the resulting neutrino spectra. The flux consists of primary neutrinos produced in processes such as χχ→ν-bar νZ and χχ→ν-bar lW, and secondary neutrinos produced via the decays of gauge bosons and charged leptons. After dealing with the neutrino propagation and flavour evolution in the Sun, we consider the prospects for detection in neutrino experiments on Earth. We compare our signal with that for annihilation to W{sup +}W{sup −}, and show that, for a given annihilation rate, the bremsstrahlung annihilation channel produces a larger signal by a factor of a few.

  9. First direct detection of solar pp neutrinos by Borexino

    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.

  10. First direct detection of solar pp neutrinos by Borexino

    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.

  11. Neutrino physics and the mirror world: how exact parity symmetry explains the solar neutrino deficit, the atmospheric neutrino anomaly and the LSND experiment

    Evidence for ν-barμ → ν-bare oscillations has been reported at LAMPF using the LSND detector. Further evidence for neutrino mixing comes from the solar neutrino deficit and the atmospheric neutrino anomaly. All of these anomalies require new physics. It is shown that all of these anomalies can be explained if the standard model is enlarged so that an unbroken parity symmetry can be defined. This explanation holds independently of the actual model for neutrino masses. Thus, it is argued that parity symmetry is not only a beautiful candidate for a symmetry beyond the standard model, but it can also explain the known neutrino physics anomalies. 41 refs

  12. Neutrino physics and the mirror world: How exact parity symmetry explains the solar neutrino deficit, the atmospheric neutrino anomaly, and the LSND experiment

    Important evidence for neutrino oscillations comes from the solar neutrino deficit and the atmospheric neutrino anomaly. Further evidence for bar νμ→ bar νe oscillations has been reported at LAMPF using the LSND detector. All of these anomalies require new physics. We show that all of these anomalies can be explained if the standard model is enlarged so that an unbroken parity symmetry can be defined. This explanation holds independently of the actual model for neutrino masses. Thus, we argue that parity symmetry is not only a beautiful candidate for a symmetry beyond the standard model, but it can also explain the known neutrino physics anomalies

  13. Helioseismic constraints to the central solar temperature and neutrino fluxes

    Ricci, B.; Berezinsky, V.; Degl'Innocenti, S.; Dziembowski, W. A.; Fiorentini, G.

    1997-01-01

    The central solar temperature T and its uncertainties are calculated in helioseismologically-constrained solar models. From the best fit to the convective radius, density at the convective radius and seismically determined helium abundance the central temperature is found to be T=1.58x10^7 K, in excellent agreement with Standard Solar Models. Conservatively, we estimate that the accuracy of this determination is Delta T/T=1.4 %, better than that in SSM. Neutrino fluxes are calculated. The low...

  14. First measurement of the integral solar neutrino flux by the Soviet-American Gallium Experiment (SAGE)

    A radiochemical 71Ga - 71Ge experiment to determine the integral flux of neutrinos from the Sun was constructed at the Baksan Neutrino Observatory. Five measurements with 30 tons of gallium indicate that the total flux is less than 50 SNU (68% CL), 74 SNU (95% CL). The results of the analysis of the first five measurements are consistent with no solar neutrino induced events being observed. The initial data indicate that the flux may be less than expected from p-p neutrinos alone, indicating that the solar neutrino problem also applies to the low energy p-p neutrinos. (R.P.) 8 refs., 2 tabs

  15. Neutrino flavor ratios as diagnostic of solar WIMP annihilation

    Lehnert, Ralf; Weiler, Thomas J.

    2008-06-01

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

  16. Global analysis of the post-SNO solar neutrino data for standard and nonstandard oscillation mechanisms

    What can we learn from solar neutrino observations? Is there any solution to the solar neutrino anomaly which is favored by the present experimental panorama? After SNO results, is it possible to affirm that neutrinos have mass? In order to answer such questions we analyze the current available data from the solar neutrino experiments, including the recent SNO result, in view of many acceptable solutions to the solar neutrino problem based on different conversion mechanisms, for the first time using the same statistical procedure. This allows us to do a direct comparison of the goodness of the fit among different solutions, from which we can discuss and conclude on the current status of each proposed dynamical mechanism. These solutions are based on different assumptions: (a) neutrino mass and mixing (b) a nonvanishing neutrino magnetic moment, (c) the existence of nonstandard flavor-changing and nonuniversal neutrino interactions, and (d) a tiny violation of the equivalence principle. We investigate the quality of the fit provided by each one of these solutions not only to the total rate measured by all the solar neutrino experiments but also to the recoil electron energy spectrum measured at different zenith angles by the Super-Kamiokande Collaboration. We conclude that several nonstandard neutrino flavor conversion mechanisms provide a very good fit to the experimental data which is comparable with (or even slightly better than) the most famous solution to the solar neutrino anomaly based on the neutrino oscillation induced by mass

  17. Which solar neutrino experiment after KamLAND and Borexino?

    We estimate how well we will know the parameters of solar neutrino oscillations after KamLAND and Borexino. The expected error on Δ m2 is few per-mille in the VO and QVO regions, few per-cent in the LMA region, and around 10% in the LOW region. The expected error on sin2 2θ is around 5%. KamLAND and Borexino will tell unambiguously which specific new measurement, dedicated to pp solar neutrinos, is able to contribute to the determination of θ and perhaps of Δ m2. The present data suggest as more likely outcomes: no measurement, or the total pp rate, or its day/night variation. (author)

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

    Franarin, Tarso; Fairbairn, Malcolm

    2016-01-01

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

  19. 7Be decay scheme and the solar-neutrino problem

    The decay scheme of 7Be has been reinvestigated. A known number of 7Be nuclei were produced in a target via the 7Li(p,n) reaction. Following activation, the yield of 478-keV ν-rays from the target was measured. From decay branching ratio to the first excited state of 7Li has been determined to be 10.8 +- 0.4%. The implications of this result for the solar neutrino problem are discussed

  20. The Scintillator Purification System for the Borexino Solar Neutrino Detector

    Benziger, J; Cadonati, L; Calaprice, F; Chen, M; Corsi, A; Cubaiu, A; Dalnoki-Veress, F; Di Pietro, G; Fernholz, R; Ford, R; Galbiati, C; Gazzana, S; Goretti, A; Harding, E; Ianni, Aldo; Ianni, Andrea; Kidner, S; Korga, G; Leung, M; Löser, F; Lombardi, P; McCarty, K; McKinsey, D; Montanari, D; Nelson, A; Orsini, M; Papp, L; Parmeggiano, S; Pocar, A; Salvo, C; Schimizzi, D; Shutt, T; Sonnenschein, A; Soricelli, F; Suvorov, Y

    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 requirements and methods to achieve system cleanliness and leak-tightness.

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

    Franarin, Tarso

    2016-01-01

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

  2. First real time detection of $^{7}$Be solar neutrinos by Borexino

    Arpesella, C; Benziger, J; Bonetti, S; Caccianiga, B; Calaprice, F; Dalnoki-Veress, F; D'Angelo, D; De Kerret, H; Derbin, A; Deutsch, M; Etenko, A; Fomenko, K; Ford, R; Franco, D; Freudiger, B; Galbiati, C; Gazzana, S; Giammarchi, M; Goeger-Neff, M; Goretti, A; Grieb, C; Hardy, S; Heusser, G; Ianni, Aldo i; Ianni, Andrea; Joyce, M; Korga, G; Kryn, D; Laubenstein, M; Leung, M; Litvinovich, E; Lombardi, P; Ludhova, L; Machulin, I; Manuzio, G; Martemianov, A; Masetti, F; McCarty, K; Meroni, E; Miramonti, L; Misiaszek, M; Montanari, D; Monzani, M E; Muratova, V; Niedermeier, L; Oberauer, L; Obolensky, M; Ortica, F; Pallavicini, M; Papp, L; Perasso, L; Pocar, A; Raghavan, R S; Ranucci, G; Razeto, A; Sabelnikov, A; Salvo, C; Schönert, S; Simgen, H; Smirnov, O; Skorokhvatov, M; Sonnenschein, A; Sotnikov, A; Sukhotin, S; Suvorov, Y; Tarasenkov, V; Tartaglia, R; Testera, G; Vignaud, D; Vitale, S; Vogelaar, R B; Von Feilitzsch, F; Wójcik, M; Zaimidoroga, O; Zavatarelli, S; Zuzel, G

    2008-01-01

    This paper reports a direct measurement of the Be7 solar neutrino signal rate performed with the Borexino low background liquid scintillator detector. This is the first real-time spectral measurement of sub-MeV solar neutrinos. The result for 0.862 MeV Be7 is 47 +- 7 (stat} +- 12 (sys} counts/(day x 100 ton), consistent with predictions of Standard Solar Models and neutrino oscillations with LMA-MSW parameters.

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

    The paper examines the feasibility of a 81Br(ν, e-)81Kr solar neutrino experiment, in order to solve the solar neutrino problem. The solar neutrino problem is where the measured solar neutrino flux on Earth is much smaller than the value calculated from the Standard model. Proposed experiments to try to resolve the mystery are described, including a bromine experiment to utilize the reaction 81Br(ν, e)81K and using Resonance Ionization Spectroscopy to count the small numbers of 81Kr atoms. (U.K.)

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

    Fifteen measurements of the solar neutrino flux have been made in a radiochemical 71Ga-71Ge experiment employing initially 30 and later 57 t of liquid metallic gallium at the Baksan Neutrino Observatory between January 1990 and May 1992. This provides an integral measurement of the flux of solar neutrinos and in particular is sensitive to the dominant, low-energy p-p solar neutrinos. SAGE observed the capture rate to be 73+18-16 (stat.)+5-7 (syst.) SNU. This represents only 56%-60% of the capture rate predicted by different Standard Solar Models. ((orig.))

  5. Study on pep and CNO solar neutrino interaction rates in Borexino

    Chavarria, Alvaro Eugenio

    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 3.28±0.56stat±0.26syst day-1(100ton)-1. Assuming the pep neutrino flux predicted by the Standard Solar Model, we obtained a constraint on the CNO solar neutrino interaction rate of techniques for the rejection of cosmogenic 11C, the dominant background in the 1-2 MeV region. Assuming the LMA-MSW solution to solar neutrino oscillations, these values correspond to solar neutrino fluxes of (1.7±0.3)×108 cm-2s-1 and <7.9×108 cm-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 [1]. [1] G. Bellini et al. First evidence of pep solar neutrinos by direct detection in Borexino. Phys.Rev.Lett., 108:051302, 2012.

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

    Abdurashitov, J N; Girin, S V; Gorbachev, V V; 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; Wark, D L; Cherry, M L; Nico, J S; Cleveland, B T; Davis, R; Lande, K; Wildenhain, P S; Elliott, S R; Wilkerson, J F

    1999-01-01

    The solar neutrino capture rate measured by the Russian-American Gallium Experiment (SAGE) on metallic gallium during the period January 1990 through December 1997 is 67.2 (+7.2-7.0) (+3.5-3.0) SNU, where the uncertainties are statistical and systematic, respectively. This represents only about half of the predicted Standard Solar Model rate of 129 SNU. All the experimental procedures, including extraction of germanium from gallium, counting of 71Ge, and data analysis are discussed in detail.

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

    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.)

  8. Absorption of the solar radiation by the solar neutrinos

    Duplancic, G; Trampetic, J

    2004-01-01

    We calculated the absorption probability of photons radiated from the surface of the Sun by a left-handed neutrino with definite mass and a typical momentum for which we choose |p_1|=0.2 MeV, producing a heavier right-handed antineutrino. We obtain the absorption probability P_{abs.}=1.27 10^{-50} and the absorption range R_{abs.}=0.89 10^4 R_{Sun}=41.4 au, using a neutrino mass difference of 50 meV and associated transition dipole moments.

  9. After Sno and Before Kamland Present and Future of Solar and Reactor Neutrino Physics

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

    2003-01-01

    We present a short review of the existing evidence in favor of neutrino mass and neutrino oscillations which come from different kinds of experiments. We focus our attention in particular on solar neutrinos, presenting a review of some recent analysis of all available neutrino oscillation evidence in Solar experiments including the recent $SNO CC$ and $NC$ data. We present in detail the power of the reactor experiment KamLAND for discriminating existing solutions to the SNP and giving accurate information on neutrino masses and mixing angles.

  10. Non-Extensive Statistics and Solar Neutrinos

    Kaniadakis, G.; A. Lavagno(Politecnico di Torino and INFN, Sezione di Torino, Torino Italy); P. Quarati

    1997-01-01

    In this paper we will show that, because of the long-range microscopic memory of the random force, acting in the solar core, mainly on the electrons and the protons than on the light and heavy ions (or, equally, because of anomalous diffusion of solar core constituents of light mass and of normal diffusion of heavy ions), the equilibrium statistical distribution that these particles must obey, is that of generalized Boltzmann-Gibbs statistics (or the Tsallis non-extensive statistics), the dis...

  11. Detecting Solar Neutrino Flares and Flavors

    Fargion, D.

    2003-01-01

    Intense solar flares originated in sun spots produce high energy particles (protons, $\\alpha$) well observable by satellites and ground-based detectors. The flare onset produces signals in different energy bands (radio, X, gamma and neutrons). The most powerful solar flares as the ones occurred on 23 February 1956, 29 September 1989 and the more recent on October 28th, and the 2nd, 4th, 13th of November 2003 released in sharp times the largest flare energies (${E}_{FL} \\simeq {10}^{31}\\div {1...

  12. Signal extraction of the solar neutrino Neutral-Current flux with the Sudbury Neutrino Observatory Neutral Current Detectors

    Phase III of the Sudbury Neutrino Observatory (SNO) experiment began after the installation of the Neutral-Current Detection (NCD) array in the D2O-filled acrylic vessel. This phase provides an independent measurement of the flux of solar neutrinos, detected via Neutral-Current interactions breaking apart deuterons with the resulting neutrons captured by the NCD array. The measurement with NCDs leads to increased precision on the solar neutrino mixing parameters. This poster presents the signal extraction methods used to measure the SNO phase III solar neutrino fluxes. The signal extraction is an extended log likelihood method designed to perform a joint fit of the photomultiplier (PMT) data and NCD data. The correlations between the observed signals and systematic uncertainties were treated by floating the nuisance parameters, both by a statistical sampling method, and by performing a Markov-Chain Monte Carlo.

  13. Large Solar Neutrino Mixing in an Extended Zee Model

    Kitabayashi, T; Kitabayashi, Teruyuki; Yasue, Masaki

    2002-01-01

    The Zee model, which employs the standard Higgs scalar ($\\phi$) with its duplicate ($\\phi^\\prime$) and a singly charged scalar ($h^+$), can utilize two global symmetries associated with the conservation of the numbers of $\\phi$ and $\\phi^\\prime$, $N_{\\phi,\\phi^\\prime}$, where $N_\\phi+N_{\\phi^\\prime}$ coincides with the hypercharge while $N_\\phi-N_{\\phi^\\prime}$ ($\\equiv X$) is a new conserved charge, which is identical to $L_e-L_\\mu-L_\\tau$ for the left-handed leptons. Charged leptons turn out to have $e$-$\\mu$ and $e$-$\\tau$ mixing masses, which are found to be crucial for the large solar neutrino mixing. In an extended version of the Zee model with an extra triplet Higgs scalar (s), neutrino oscillations are described by three steps: 1) the maximal atmospheric mixing is induced by democratic mass terms supplied by $s$ with $X$=2 that can initiate the type II seesaw mechanism for the smallness of these masses; 2) the maximal solar neutrino mixing is triggered by the creation of radiative masses by $h^+$ with...

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

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

    2003-07-01

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

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

    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.

  16. Neutrino Solar Flare detection for a saving alert system of satellites and astronauts

    Fargion, Daniele

    2011-01-01

    Largest Solar Neutrino Flare may be soon detectable by Deep Core neutrino detector immediately and comunicate to satellites or astronauts. Its detection is the fastest manifestation of a later (tens minutes,hours) dangerous cosmic shower. The precursor trigger maybe saving satellites and even long flight astronauts lives. We shall suggest how. Moreover their detection may probe the inner solar flare acceleration place as well as the neutrino flavor mixing in a new different parameter windows. We show the updated expected rate and signature of neutrinos and antineutrinos in largest solar flare for present tens Megaton Deep Core telescope at tens Gev range. Speculation for additional Icecube gigaton array signals are also considered.

  17. Neutrino Solar Flare detection for a saving alert system of satellites and astronauts

    Fargion, Daniele

    2011-01-01

    Largest Solar Neutrino Flare may be soon detectable by Deep Core neutrino detector immediately and comunicate to satellites or astronauts. Its detection is the fastest manifestation of a later (tens minutes,hours) dangerous cosmic shower. The precursor trigger maybe saving satellites and even long flight astronauts lives. We shall suggest how. Moreover their detection may probe the inner solar flare acceleration place as well as the neutrino flavor mixing in a new different parameter windows....

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

    Ejiri, Hiroyasu

    2016-01-01

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

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

    Galbiati, C.; 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.; Dangelo, 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.; Borexino Collaboration

    2012-07-01

    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.l±0.6stat±0.3syst counts/(day-100 ton). Assuming the pep neutrino flux predicted by the Standard Solar Model, we obtained a constraint on the CNO solar neutrino interaction rate of techniques for the rejection of cosmogenic 11C, the dominant background in the 1-2 MeV region. Assuming the MSW-LMA solution to solar neutrino oscillations, these values correspond to solar neutrino fluxes of (1.6±0.3)×l08cm-2s-1 and <7.7×l08 cm-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.

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

    ,

    2011-01-01

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

  1. Low energy neutrino reactions in water Cerenkov detectors

    The author discusses the charged-current nuclear response of water Cerenkov detectors to neutrinos from supernovae, the neutral current nuclear response of carbon-bearing liquid scintillation detectors, and the possibility of detecting 8B solar neutrinos with a water Cerenkov detector enriched in 18O. 12 refs., 1 fig., 2 tabs

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

    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).

  3. Implications of the Recent Results of Solar Neutrino Experiments

    Maris, M.; Petcov, S. T.

    2002-12-01

    Detailed predictions for the D-N asymmetry for the Super-Kamiokande and SNO experiments, as well as for the ratio of the CC and NC event rates measured by SNO, in the cases of the LMA MSW and of the LOW solutions of the solar neutrino problem, are presented. The possibilities to use the forthcoming SNO data on these two observables to discriminate between the LMA and LOW solutions and/or to further constrain the regions of the two solutions are also discussed.

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

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

    2016-08-01

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

  5. The chemical composition of the sun from helioseismic and solar neutrino data

    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 7Be and 8B 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 εO = 8.85 ± 0.01 and εFe = 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 34 and S 17) that differ at the ∼1σ level from those presently adopted.

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

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

    2015-01-01

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

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

    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 1010 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 1010 neutrinos cm-2 s-1, in agreement with the value of (5.95 ± 0.06) x 1010 neutrinos cm-2 s-1 predicted by the standard solar model

  8. Neutrinos

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

    2013-01-01

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

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

    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 71Ge 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

  10. Vacuum oscillations and the distorted solar neutrino spectrum observed by Superkamiokande

    Berezinsky, V.; Fiorentini, G.; Lissia, M.

    1998-01-01

    The excess of solar-neutrino events above 13 MeV that has been recently observed by Superkamiokande can be explained by vacuum oscillations (VO). If the boron neutrino flux is 20% smaller than the standard solar model (SSM) prediction and the chlorine signal is assumed 30% (or 3.5 sigmas) higher than the measured one, there exists a VO solution that reproduces both the observed boron neutrino spectrum, including the high energy distortion, and the other measured neutrino rates. This solution ...

  11. Solar neutrino measurements with Super-Kamiokande III

    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.

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

    Vergados, J D

    2016-01-01

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

  13. Solar neutrino physics oscillations: Sensitivity to the electronic density in the Sun's core

    Lopes, Ilídio; 10.1088/0004-637X/765/1/14

    2013-01-01

    Solar neutrinos coming from different nuclear reactions are now detected with a high statistics. Consequently, an accurate spectroscopic analysis of the neutrino fluxes arriving on the Earth's detectors become 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, that we propose to get the radial solar electronic density profile, is almost independent of the solar model.

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

    We analyse the recently published results from solar neutrino experiments SNO Phase-III and SAGE Part-III and show their constraints on solar neutrino oscillation parameters, especially for the mixing angle θ12. Through a global analysis using all existing data from SK, SNO, Ga and Cl radiochemical experiments and long base line reactor experiment KamLAND, we obtain the parameters shown. We also find that the discrepancy between the KamLAND and solar neutrino results can be reduced by choosing a small non-zero value for the mixing angle θ13. (the physics of elementary particles and fields)

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

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

    2002-01-01

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

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

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

    2015-01-01

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

  17. Constraining alternative gravity theories using the solar neutrino problem

    The neutrino flavor oscillation is studied in some classes of alternative gravity theories in a plane specified by θ = π/2, exploiting the spherical symmetry and general equations for oscillation phases are given. We first calculate the phase in a general static spherically symmetric model and then we discuss some spherically symmetric solutions in alternative gravity theories. Among them we discuss the effect of a cosmological term in the Schwarzschild–(anti)de Sitter solution, which is the vacuum solution in F(R) theory and the effect of charge and the Gauss–Bonnet coupling parameter on the oscillation phase is presented. Finally, we discuss a charged solution with a spherical symmetry in F(R) theory and also its implication to the oscillation phase. We calculate the oscillation length and transition probability in these spherically symmetric spacetimes and have presented a graphical representation for the transition probability with various choices for parameters in our theory. From this, we have constrained parameters appearing in these alternative theories using standard solar neutrino results. (paper)

  18. Neutrino physics with JUNO

    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

    . Detection of neutrinos from all past core-collapse supernova explosions in the visible universe with JUNO would further provide valuable information on the cosmic star-formation rate and the average core-collapse neutrino energy spectrum. Antineutrinos originating from the radioactive decay of uranium and thorium in the Earth can be detected in JUNO with a rate of ˜400 events per year, significantly improving the statistics of existing geoneutrino event samples. Atmospheric neutrino events collected in JUNO can provide independent inputs for determining the MH and the octant of the {θ }23 mixing angle. Detection of the 7Be and 8B solar neutrino events at JUNO would shed new light on the solar metallicity problem and examine the transition region between the vacuum and matter dominated neutrino oscillations. Regarding light sterile neutrino topics, sterile neutrinos with {10}-5 {{{eV}}}2\\lt {{Δ }}{m}412\\lt {10}-2 {{{eV}}}2 and a sufficiently large mixing angle {θ }14 could be identified through a precise measurement of the reactor antineutrino energy spectrum. Meanwhile, JUNO can also provide us excellent opportunities to test the eV-scale sterile neutrino hypothesis, using either the radioactive neutrino sources or a cyclotron-produced neutrino beam. The JUNO detector is also sensitive to several other beyondthe-standard-model physics. Examples include the search for proton decay via the p\\to {K}++\\bar{ν } decay channel, search for neutrinos resulting from dark-matter annihilation in the Sun, search for violation of Lorentz invariance via the sidereal modulation of the reactor neutrino event rate, and search for the effects of non-standard interactions. The proposed construction of the JUNO detector will provide a unique facility to address many outstanding crucial questions in particle and astrophysics in a timely and cost-effective fashion. It holds the great potential for further advancing our quest to understanding the fundamental properties of neutrinos, one

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

    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> 7Be) solar neutrinos. A GENIUS Test Facility has just been funded and will come into operation by the end of 2001

  20. The polarized electron target as a new solar-neutrino detector

    Misiaszek, M; Sobkow, W

    2006-01-01

    In this paper, we analyze the scattering of solar neutrinos on the polarized electron target, and predict how the effect of parity violation in weak interactions may help to distinguish neutrino signal from detector background. We indicate that the knowledge of the Sun motion across the sky is sufficient to predict the day/night asymmetry in the $(\

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

    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...

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

    Discrepancies between standard model predictions and observed values of the solar neutrinos flux are described. A proposed experiment is discussed including facilities and compounds required, signal level, and background effects. 16 refs., 2 figs., 1 tab

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

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

    2008-01-01

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

  4. Day-Night Asymmetries in Active-Sterile Solar Neutrino Oscillations

    Long, H W; Giunti, C

    2013-01-01

    Day-night asymmetries in active-sterile solar neutrino oscillations are discussed in the general $3+N_{s}$ mixing framework with three active and N_s sterile neutrinos. Analytical expressions of the probability of neutrino flavor transitions in the Earth in the perturbative approximation and in the slab approximation are presented and the effects of active-sterile mixing and of the CP-violating phases are discussed. The accuracy of the analytical approximations and the properties of the day-night asymmetries are illustrated numerically in the 3+1 neutrino mixing framework.

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

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

    1994-08-01

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

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

    Bahcall, J N; Christensen-Dalsgaard, J; Clevelend, B T; Degl'Innocenti, S; Filippone, B W; Glasner, A; Kavanagh, R W; Koonin, S E; Lande, K; Kanganke, K; Parker, P D; Pinsonneault, M H; Proffitt, C R; Shoppa, T D; John N Bahcall et al

    1994-01-01

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

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

    A search has been made for neutrinos from the hep reaction in the Sun and from the diffuse supernova neutrino background (DSNB)using data collected during the first operational phase of the Sudbury Neutrino Observatory, with an exposure of 0.65 kilotons-years. For the hep neutrino search, two events are observed in the effective electron energy range of 14.3 MeVeffeff<35 MeV and, consequently, an upper limit on the nu e component of the DSNB flux in the neutrino energy range of 22.9 MeV< E nu<36.9 MeV of 70 cm-2-1 is inferred at the 90 percent confidence level. This is an improvement by a factor of 6.5 on the previous best upper limit on the hep neutrino flux and by two orders of magnitude on the previous upper limit on the nu e component of the DSNB flux

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

    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 1010 neutrino/(cm2 s). The value of the flux of the pp-neutrinos, originating in the Sun thermonuclear reactions, is equal to (7.6 ± 2.0) x 1010 neutrino/(cm2 s), which agrees well with the standard solar model (5.95 ± 0.6) x 1010 neutrino/(cm2 s)

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

    It has now been shown that it is feasible to measure the 7Be neutrino source in the sun by using the reaction 81Br(nu,e-)81Kr in a radiochemical experiment. Such an experiment would be quite similar to the Davis, Cleveland, and Rowley method for measuring the 8B neutrino using 37Cl(nu,e-)37Ar except that the resonance ionization spectroscopy (RIS) method (instead of decay counting) would be employed to count the 2 x 105-yr 81Kr atoms

  10. Proposed solar neutrino experiment using 81Br(ν,e-)81Kr

    It has now been show that it is feasible to measure the 7Be neutrino source in the sun by using the reaction 81Br(ν,e-)81Kr in a radiochemical experiment. Such an experiment would be quite similar to the Davis, Cleveland, and Rowley method for measuring the 8B neutrino using 37Cl(ν,e-)37Ar except that the resonance ionization spectroscopy (RIS) method (instead of decay counting) would be employed to count the 2 x 105-yr 81Kr atoms

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

    Pershing, Teal; SNO+ Collaboration

    2016-03-01

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

  12. A natural framework for solar and 17 keV neutrinos

    Burgess, C P; Luty, M A; Luty, Markus

    1992-01-01

    Motivated by recent experimental claims for the existence of a 17 keV neutrino and by the solar neutrino problem, we construct a class of models which contain in their low-energy spectrum a single light sterile neutrino and one or more Nambu-Goldstone bosons. In these models the required pattern of breaking of lepton-number symmetry takes place near the electroweak scale and all mass heirarchies are technically natural. The models are compatible with all cosmological and astrophysical constraints, and can solve the solar neutrino problem via either the MSW effect or vacuum oscillations. The deficit in atmospheric muon neutrinos seen in the Kamiokande and IMB detectors can also be explained in these models.

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

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

    2006-01-01

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

  14. The Simplest Resonant Spin-Flavour Solution to the Solar Neutrino Problem

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

    2001-01-01

    We re-analyse the resonant spin-flavour (RSF) solutions to the solar neutrino problem in the framework of analytic solutions to the solar magneto-hydrodynamics (MHD) equations. By substantially eliminating the arbitrariness associated to the magnetic field profile due to both mathematical consistency and physical requirements we propose the simplest scheme (MHD-RSF, for short) for solar neutrino conversion using realistic static MHD solutions. Using such effective two-parameter scheme we perform the first 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. We find our MHD-RSF fit to be somewhat better than those obtained for the favored neutrino os...

  15. Real-time spectroscopy of solar pp-neutrinos using 150Nd

    The potential real-time spectroscopy of solar pp-neutrinos using 150Nd as target is investigated. The threshold of 196 keV would be the lowest of all solar neutrino experiments running so far. Experimental rates and parameters are discussed, about 906 SNU can be expected from pp-neutrinos and another 574 SNU from 7Be. Furthermore, it is investigated whether charged current reactions might cause a new background component for future double beta decay experiments based on a large amount of 150Nd.

  16. Real-time spectroscopy of solar pp neutrinos using Nd-150

    Zuber, K.

    2011-01-01

    The potential real-time spectroscopy of solar pp neutrinos using Nd-150 as target is investigated. The threshold of 196 keV would be the lowest of all solar neutrino experiments running so far. Experimental rates and parameters are discussed, about 580 SNU can be expected from pp-neutrinos and another 367 SNU from Be-7. Furthermore, it is investigated whether charged current reactions might cause a new background component for future double beta decay experiments based on a large amount of Nd...

  17. Real-time spectroscopy of solar pp-neutrinos using {sup 150}Nd

    Zuber, K., E-mail: Zuber@physik.tu-dresden.de [Institut fuer Kern- und Teilchenphysik, Technische Universitaet Dresden (Germany)

    2012-03-13

    The potential real-time spectroscopy of solar pp-neutrinos using {sup 150}Nd as target is investigated. The threshold of 196 keV would be the lowest of all solar neutrino experiments running so far. Experimental rates and parameters are discussed, about 906 SNU can be expected from pp-neutrinos and another 574 SNU from {sup 7}Be. Furthermore, it is investigated whether charged current reactions might cause a new background component for future double beta decay experiments based on a large amount of {sup 150}Nd.

  18. 7Be solar neutrino line: A reflection of the central temperature distribution of the Sun

    A precise test of the theory of stellar evolution can be performed by measuring the average difference in energy between the neutrino line produced by 7Be electron capture in the solar interior and the corresponding neutrino line produced in a terrestrial laboratory. This energy shift is calculated to be 1.29 keV (to an accuracy of a few percent) for the dominant ground-state to ground-state transition. The energy shift is approximately equal to the average temperature of the solar core, computed by integrating the temperature over the solar interior with a weighting factor equal to the locally produced 7Be neutrino emission. Therefore, a measurement of the energy shift is a measurement of the central temperature distribution of the Sun. The energy profile of the 7Be line is derived analytically and is evaluated numerically. The line shape is asymmetric: on the low-energy side, the line shape is Gaussian with a half-width at half-maximum of 0.6 keV and, on the high-energy side, the line shape is exponential with a half-width at half-maximum of 1.1 keV. The effective temperature of the high-energy exponential tail is 15x106 K. The energy profile of the 7Be neutrino line should be taken into account in calculations of vacuum neutrino oscillations and of the absorption cross section for 7Be solar neutrinos incident on 7Li nuclei. The characteristic modulation of the 7Be line shape that would be caused by either vacuum neutrino oscillations or by matter-enhanced (MSW) neutrino oscillations is shown to be small. Other frequently discussed weak interaction solutions to the solar neutrino problem are also not expected to change significantly the line profile

  19. Low energy neutrinos in Super-Kamiokande

    Sekiya, Hiroyuki

    2016-05-01

    Super-Kamiokande (SK), a 50 kton water Cherenkov detector, observes 8B solar neutrinos via neutrino-electron elastic scattering. The analysis threshold was successfully lowered to 3.5 MeV (recoil electron kinetic energy) in SK-IV. To date SK has observed solar neutrinos for 18 years. An analysis regarding possible correlations between the solar neutrino flux and the 11 year solar activity cycle is shown. With large statistics, SK searches for distortions of the solar neutrino energy spectrum caused by the MSW resonance in the core of the sun. SK also searches for a day/night solar neutrino flux asymmetry induced by the matter in the Earth. The Super-Kamiokande Gd (SK-Gd) project is the upgrade of the SK detector via the addition of water-soluble gadolinium (Gd) salt. This modification will enable it to efficiently identify low energy anti-neutrinos. SK-Gd will pursue low energy physics currently inaccessible to SK due to backgrounds. The most important will be the world’s first observation of the diffuse supernova neutrino background. The main R&D program towards SK-Gd is EG ADS: a 200 ton, fully instrumented tank built in a new cavern in the Kamioka mine.

  20. Neutrino astrophysics: A research briefing

    This report contains the following discussions on neutrino astrophysics: ongoing solar neutrino experiments; solar neutrino experiments under construction; developing new solar neutrino detectors; high-energy neutrinos; high-energy neutrino experiments under construction; and a kilometer-scale high-energy neutrino telescope

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

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

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

    Davis, Jonathan H

    2016-01-01

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

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

    Shin, Jae Won

    2016-01-01

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

  4. Prospects for the measurement of pep and CNO solar neutrino rates with Borexino

    Chavarria, Alvaro

    2011-04-01

    Borexino is the only detector currently able to perform neutrino spectroscopy below 2 MeV. The Borexino Collaboration has already published the first and only real-time measurement of the ^7Be neutrino flux from the Sun. Of great interest are also the measurements of the CNO and pep neutrino rates. Knowledge of the CNO neutrino rate is key to answer the Solar Metallicity Problem, while the pep neutrinos are an excellent probe for the vacuum-matter transition region of the LMA-MSW solution to the Solar Neutrino Problem. The main challenge for these measurements is the characterization and removal of cosmogenic and radiogenic background in the scintillator. I will present data analysis techniques that can significantly reduce the cosmogenic ^11C background in Borexino's energy spectrum, which should allow for the measurement of the pep neutrino rate. Additionally, I will discuss the status of the detector in terms of radiogenic background and the possibility for the eventual measurement of the CNO neutrino rate with Borexino.

  5. Measurement of the response of a gallium metal solar neutrino experiment to neutrinos from a 51Cr source

    The neutrino capture rate measured by the Russian-American Gallium Experiment is well below that predicted by solar models. To check the response of this experiment to low-energy neutrinos, a 517 kCi source of 51Cr was produced by irradiating 512.7 g of 92.4%-enriched 50Cr in a high-flux fast neutron reactor. This source, which mainly emits monoenergetic 747-keV neutrinos, was placed at the center of a 13.1 ton target of liquid gallium and the cross section for the production of 71Ge by the inverse beta decay reaction 71Ga(νe,e-)71Ge was measured to be [5.55±0.60thinsp(stat)±0.32thinsp(syst)]x10-45thinspcm2. The ratio of this cross section to the theoretical cross section of Bahcall for this reaction is 0.95 ±0.12 (expt)-0.027+0.035 (theor) and to the cross section of Haxton is 0.87±0.11 (expt)±0.09 (theor). This good agreement between prediction and observation implies that the overall experimental efficiency is correctly determined and provides considerable evidence for the reliability of the solar neutrino measurement. copyright 1999 The American Physical Society

  6. Solar Neutrinos: Probing the Quasi-Isothermal Solar Core Produced by SUSY Dark Matter Particles

    Lopes, Ilidio; Silk, Joseph

    2001-01-01

    SNO measurements strongly constrain the central temperature of the Sun within a precision of much less than 1%. This result can be used to constrain the parameter space of SUSY dark matter particle candidates. In this first analysis we find a lower limit for the WIMP mass of 60 GeV, well above the WIMP evaporation limit of 10 GeV. Furthermore, in the event that WIMPs create a quasi-isothermal core within the Sun, they will produce a peculiar distribution of the solar neutrino fluxes measured ...

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

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

    2013-01-01

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

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

    Tanasa, A

    2001-01-01

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

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

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

    2013-01-01

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

  10. Experimental Results on Neutrino Oscillations Using Atmospheric, Solar and Accelerator Beams

    The innermost secrets of the mysterious neutrino are being revealed in underground detectors. Recent data on atmospheric neutrinos, primarily from the Super-Kamiokande experiment, confirm the neutrino flavor mixing and non-zero masses. The high precision measurement of angular distribution allows to determine the value of Δm2 between 0.0013 eV2 and 0.0054 eV2 at 90% c.l. Studies of up-down asymmetries in different event samples indicate that νμ↔ντ oscillations are more likely explanation of the data than νμ↔νs. The deficit of the observed solar neutrino flux compared to the predictions of the standard solar model, often interpreted by neutrino oscillations, is further studied in the SuperKamiokande detector. The energy spectrum is measured above 5.5 MeV for the Sun's positions above and below the horizon. A day-night effect is observed at a statistical significance of 2 σ. The K2K (KEK to Kamioka) is the first long-baseline neutrino-oscillation experiment. During runs in 1999 the first 3 events were observed in the SuperKamiokande detector caused by neutrinos produced at the KEK accelerator at a distance of 250 km. The predicted number of events without any oscillations is 12.3+1.7-1.9. (author)

  11. Detection of solar and supernova neutrinos. The 2002 nobel prize for physics

    The author reviews the birth of neutrino astronomy, with special emphasis on the pioneering contributions to the detection of solar and supernova neutrinos of the 2002 Nobel Prize winners, Raymond Davis Jr and Masatoshi Koshiba. The author describes briefly the recent developments in this rapidly growing field as well as the prospects for the near future, and concludes with a few thoughts that come from reflecting over the history

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

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

    2002-01-01

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

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

    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 7Be 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. Central temperature of the Sun can be measured via the 7Be solar neutrino line

    A precise test of the theory of stellar evolution can be performed by measuring the difference in average energy between the neutrino line produced by 7Be electron capture in the solar interior and the corresponding neutron line produced in a terrestrial laboratory. The high temperatures in the center of the Sun broaden the line asymmetrically, FWHM =1.6 keV, and cause an average energy shift of 1.3 keV. The width of the 7Be neutrino line should be taken into account in calculations of vacuum neutrino oscillations

  15. Spectroscopy of low energy solar neutrinos using CdTe detectors

    Zuber, K.

    2002-01-01

    The usage of a large amount of CdTe(CdZnTe) semiconductor detectors for solar neutrino spectroscopy in the low energy region is investigated. Several different coincidence signals can be formed on five different isotopes to measure the Be-7 neutrino line at 862 keV in real-time. The most promising one is the usage of Cd-116 resulting in 89 SNU. The presence of Te-125 permits even the real-time detection of pp-neutrinos. A possible antineutrino flux above 713 keV might be detected by capture o...

  16. The role of electron-screening deformations in solar nuclear fusion reactions and the solar neutrino puzzle

    Liolios, Theodore E.

    2000-01-01

    Thermonuclear fusion reaction rates in the solar plasma are enhanced by the presence of the electron cloud that screens fusing nuclei. The present work studies the influence of electron screening deformations on solar reaction rates in the framework of the Debye-Huckel model. These electron-ion cloud deformations, assumed here to be static and axially symmetric, are shown to be able to considerably influence the solar neutrino fluxes of the pp and the CNO chains, with reasonable changes in th...

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

    Lopes, I.; ~Silk, J.

    2013-01-01

    Recent observations of solar twin stars with planetary systems like the Sun, have uncovered that these present a peculiar surface chemical composition. This is believed to be related to the formation of earth-like planets. This suggests that twin stars have a radiative interior that is richer in heavy elements than their envelopes. Moreover, the current standard solar model does not fully agree with the helioseismology data and solar neutrino flux measurements. In this work, we find that this...

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

    We analyse the recently published results from solar neutrino experiments SNO Phase-III and SAGE Part-III and show their constraints on solar neutrino oscillation parameters, especially for the mixing angle θ12. Through a global analysis using all existing data from SK, SNO, Ga and Cl radiochemical experiments and long base line reactor experiment KamLAND , we obtain the parameters Δm122=7.684-0.208+0.212 x 10-5 eV2, tan2θ12=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 θ13. (authors)

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

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

    1999-01-01

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

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

    YANG Ping; LIU Qiu-Yu

    2009-01-01

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

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

    Essig, Rouven; Slone, Oren; Volansky, Tomer

    2016-01-01

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

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

    Elliott, Steven Ray [Los Alamos National Laboratory

    2008-01-01

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

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

    Solomey, Nickolas

    2016-05-01

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

  4. PeP-neutrino Detection by Lithium Detector as a Direct Way to Search for Oscillation of Solar Neutrinos

    Kopylov, A V

    2000-01-01

    The high sensitivity of lithium detector to pep- and Be7-neutrinos makes a lithium radiochemical detector a powerful tool for the search of the oscillations of solar neutrinos. The first phase of lithium experiment on the installation with 10 tons of metallic lithium will enable to collect data within 1 year of measurements to provide very definite information about SMA MSW solution. the second phase with 10 modules 10 tons each will measure the semiannual variations of the signal, thus the contributions of pep- and Be7-lines will be weighted, what will give a "smoking-gun" evidence about "just-so" solution for large mixing angles and delta-m2 about 10-10 - 10-9 eV2. If both regions are not confirmed the results of lithium detector can be interpreted in favor of LMA MSW solution.

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

    Guo, Wan-Lei

    2015-01-01

    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 $\\chi \\chi \\rightarrow \

  6. Theoretical constraints on the vacuum oscillation solution to the solar neutrino problem

    Casas, Alberto J.; Espinosa, J. R.; Ibarra, A.; Navarro, I..

    1999-01-01

    The vacuum oscillation (VO) solution to the solar anomaly requires an extremely small neutrino mass splitting, Delta m^2_{sol}\\leq 10^{-10} eV^2. We study under which circumstances this small splitting (whatever its origin) is or is not spoiled by radiative corrections. The results depend dramatically on the type of neutrino spectrum. If m_1^2 \\sim m_2^2 \\geq m_3^2, radiative corrections always induce too large mass splittings. Moreover, if m_1 and m_2 have equal signs, the solar mixing angle...

  7. Full simulation of the Sudbury Neutrino Observatory proportional counters

    The third phase of the Sudbury Neutrino Observatory (SNO) experiment added an array of 3He proportional counters to the detector. The purpose of this neutral-current detection (NCD) array was to observe neutrons resulting from neutral-current solar-neutrino-deuteron interactions. We have developed a detailed simulation of current pulses from NCD array proportional counters, from the primary neutron capture on 3He through NCD array signal-processing electronics. This NCD array MC simulation was used to model the alpha-decay background in SNO's third-phase 8B solar-neutrino measurement.

  8. Full simulation of the Sudbury Neutrino Observatory proportional counters

    Beltran, B; Cai, B.; Cox, G.A.; Deng, H.; Detwiler, J.; Formaggio, J.A.; Habib, S.; Hallin, A.L.; Hime, A.; Huang, M.; Kraus, C.; Leslie, H.R.; Loach, J.C.; Martin, R.; McGee, S.; Miller, M.L.; Monreal, B.; Monroe, J.; Oblath, N.S.; Peeters, S.J.M.; Poon, A.W.P.; Prior, G.; Rielage, K.; Robertson, R.G.H.; Smith, M.W.E.; Stonehill, L.C.; Tolich, N.; Van Wechel, T.; Wan Chan Tseung, H.; Wendland, J.; Wilkerson, J.F.; Wright, A.

    2011-01-01

    The third phase of the Sudbury Neutrino Observatory (SNO) experiment added an array of 3He proportional counters to the detector. The purpose of this Neutral Current Detection (NCD) array was to observe neutrons resulting from neutral-current solar neutrino-deuteron interactions. We have developed a detailed simulation of the current pulses from the NCD array proportional counters, from the primary neutron capture on 3He through the NCD array signal-processing electronics. This NCD array Monte Carlo simulation was used to model the alpha-decay background in SNO's third-phase 8B solar-neutrino measurement.

  9. Solar oscillations, gravitational multipole field of the sun and the solar neutrino paradox

    The visual solar oblateness work and the solar seismological work on the internal rotation of the sun are reviewed and their implications concerning the static gravitational multipole moments of the sun are discussed. The results of this work are quite deviant which is indicative of the complexity encountered and of the necessity for continued studies based on a diverse set of observing techniques. The evidence for phase-locked internal gravity modes of the sun is reviewed and the implications for the solar neutrino paradox are discussed. The rather unique possibility for testing the relevance which the phase-locked gravity modes have to this paradox is also noted. The oscillating perturbations in the sun's gravitational field produced by the classified internal gravity modes and the phase-locked modes are inferred from the observed temperature eigenfunctions. Strains of the order of 10-18 in gravitational radiation detectors based on free masses are inferred for frequencies near 100 μHz. The relevance of these findings is discussed in terms of a new technique for use in solar seismological studies and of producing background signals in studies of low-frequency gravitational radiation. 64 refs., 2 figs

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

    Stothers, R. B.; Ezer, D.

    1972-01-01

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

  11. Implications on neutrino oscillation plus decay from recent solar neutrino data

    Indumathi, D

    2002-01-01

    Recently the Sudbury Neutrino Observatory (SNO) has measured both the rates as well as the day-night asymmetries in the flux of neutrinos from the Sun in the charged-current (CC), neutral-current (NC) and elastic scattering (ES) channels. Motivated by the small but negative day-night asymmetry in the NC channel at SNO (1.2 standard deviations away from zero), we consider whether such a non-zero asymmetry can be generated in a framework where active neutrinos can both oscillate and decay, since the NC day-night asymmetry is zero in a frame-work that includes pure oscillations of active flavours. We find that the neutral current day-night asymmetry is strictly zero when we include both oscillations and decay. The result holds for arbitrary number of active neutrino species, with some reasonable assumptions on the decay parameters. Hence, a non-zero asymmetry in the neutral current sector, if it survives, can only come from oscillations/decay into sterile flavours. We also examine the allowed region of parameter...

  12. Neutrino astronomy

    In recent years, there has been considerable discussion on the field called neutrino astronomy which represents exciting prospect in that it deals with the radiations which are distinct from electromagnetic spectra. Because of the unique, enormously long interaction mean free path of neutrinos, this field can in principle give extremely valuable complementary information about the universe, in particular about the conditions in the core of the sun and the energy balance and extent of the galaxy. Remarkable difference is observed when outlining of the development of neutrino astronomy is attempted in a manner similar to that for radio astronomy. The development on solar neutrinos, calculation of solar neutrino flux, solar neutrino search experiments, efforts to resolve the discrepancy between theory and experiment concerning the neutrinos from the sun, chemistry consideration, nuclear physics problems, astrophysical calculation, neutrino physics and other physical accomplishments are reviewed in the report. (Iwase, T.)

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

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

    1975-01-01

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

  14. Particle physics candidates for the cosmion solution to the solar neutrino problem

    This paper discuss several particle physics candidates for the cosmic solution to the solar neutrino problem. Some of these candidates are: Cold dark matter; No conserved particle number; Conserved particle number but No cosmic asymmetry; and Conserved particle number and a cosmic asymmetry. Also outlined are their properties and methods of detecting them. 23 refs., 8 figs

  15. Magnetic moment solution to the solar neutrino problem, anticorrelation with sunspot activity and challenges for future experiments

    The analysis of the most recent solar neutrino data in the light of the resonant spin flip flavour conversion of neutrinos in the Sun suggests the existence of two possible solutions for the solar neutrino problem, one of them associated with a neutrino flavour mass square difference of the order of 10-8 eV2 and the other of the order of 10-5 eV2. The magnetic moment is in the range μν =(10-12-10-11) μB. In the first possibility the most energetic neutrinos will have their resonance in the solar convective zone. This indicates that the forthcoming SNO and Icarus experiments are very well placed to test this solution through the anticorrelation effect with sunspot activity that may be present in the Homestake data but still remains an open question. (orig.). With 4 figs., 2 tabs

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

    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

  17. Low-lying non-normal parity states in 8B measured by proton elastic scattering on 7Be

    Yamaguchi, H; Amadio, G; Fujikawa, H; Teranishi, T; Saito, A; He, J J; Nishimura, S; Togano, Y; Kwon, Y K; Niikura, M; Iwasa, N; Inafuku, K; Khiem, L H

    2008-01-01

    A new measurement of proton resonance scattering on 7Be was performed up to the center-of-mass energy of 6.7 MeV using the low-energy RI beam facility CRIB (CNS Radioactive Ion Beam separator) at the Center for Nuclear Study of the University of Tokyo. The excitation function of 7Be+p elastic scattering above 3.5 MeV was measured successfully for the first time, providing important information about the resonance structure of the 8B nucleus. The resonances are related to the reaction rate of 7Be(p, gamma)8B, which is the key reaction in solar 8B neutrino production. Evidence for the presence of two negative parity states is presented. One of them is a 2- state observed as a broad s-wave resonance, the existence of which had been questionable. Its possible effects on the determination of the astrophysical S-factor of 7Be(p, gamma)8B at solar energy are discussed. The other state had not been observed in previous measurements, and its spin and parity were determined as 1-.

  18. A new three-flavor oscillation solution of the solar neutrino deficit in R-parity violating supersymmetry

    We present a solution of the solar neutrino deficit using three flavors of neutrinos and R-parity non-conserving supersymmetry. In this model, in vacuum, the νe is massless and unmixed, mass and mixing being restricted to the νμ-ντ sector only, which we choose in consistency with the requirements of the atmospheric neutrino anomaly. The flavor changing and flavor diagonal neutral currents present in the model and the three-flavor picture together produce an energy dependent resonance-induced νe-νμ mixing in the sun. This mixing plays a key role in the new solution to the solar neutrino problem. The best fit to the solar neutrino rates and spectrum (1258-day SK and 241-day SNO data) requires a mass square difference of ∝10-5 eV2 in vacuum between the two lightest neutrinos. This solution cannot accommodate a significant day-night effect for solar neutrinos nor CP violation in terrestrial neutrino experiments. (orig.)

  19. Neutrino properties

    Valle, José W F

    1996-01-01

    A brief sketch is made of the present observational status of neutrino properties, with emphasis on the hints from solar and atmospheric neutrinos, as well as cosmological data on the amplitude of primordial density fluctuations. Implications of neutrino mass in particle accelerators, astrophysics and cosmology are discussed.

  20. Neutrino astrophysics

    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)

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

    Desai, Shantanu; Liu, Dawei W.

    2016-09-01

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

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

    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)

  3. On the Size of the Dark Side of the Solar Neutrino Parameter Space

    González-Garciá, M Concepción

    2000-01-01

    We present an analysis of the MSW neutrino oscillation solutions of the solarneutrino problem in the framework of two-neutrino mixing in the enlargedparameter space $(\\Delta m^2, \\tan^2\\theta)$ with $\\theta \\in(0,\\frac{\\pi}{2})$. Recently, it was pointed out that the allowed region ofparameters from a fit to the measured total rates can extend to values $\\theta\\geq \\frac{\\pi}{4}$ (the so called ``dark side'') when higher confidence levelsare allowed. The purpose of this letter is to reanalize the problem includingall the solar neutrino data available, to discuss the dependence on thestatistical criteria in the determination of the CL of the ``dark side'' and toextract the corresponding limits on the largest mixing allowed by the data. Ourresults show that when the Super-Kamiokande data on the zenith angledistribution of events and the spectrum information is included, the regionsextend more into the dark side.

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

    Faid, B; Lisi, E; Montanino, D

    1999-01-01

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

  5. Measurement of the $^{7}$Be$(p,\\gamma)^{8}$B Cross-Section with an Implanted Target

    2002-01-01

    % IS366\\\\ \\\\ The $^7$Be(p,$\\gamma)^8$B capture reaction is of major importance to the physics of the sun and the issues of the ``solar neutrino puzzle'' and neutrino masses. We report here on a new determination of the absolute cross section of this reaction, using a novel method which overcomes some of the major experimental uncertainties of previous measurements. We utilize an implanted $^7$Be target and a uniformly scanned particle beam larger than the target spot, eliminating issues of target homogeneity and backscattering loss of $^8$B reaction products. The target was produced using a beam of 1.8 10$^{10}$/s $^7$Be nuclei extracted at ISOLDE(CERN) from a graphite target bombarded by 1 GeV protons in a two-step resonant laser ionization source. The $^7$Be nuclei were directly implanted into a copper substrate to obtain a target of 2 mm diameter with a total of 3.10$^{15}$ atoms. The measurement of the $^8$B production cross section was carried out at the Van de Graaff laboratory of the Weizmann Institute...

  6. Breakup of loosely bound nuclei as indirect method in nuclear astrophysics. 8B, 9C, 23Al

    We discuss the use of one-nucleon breakup reactions of loosely bound nuclei at intermediate energies as an indirect method in nuclear astrophysics. These are peripheral processes, therefore from breakup reaction data we can extract asymptotic normalization coefficients (ANC) from which reaction rates of astrophysical interest can be precisely evaluated. In particular, the breakup of 8B and 9C is described in detail in terms of an extended Glauber model. The results of this new analysis lead to the astrophysical factor S17(0) = 18.7 ± 1.9 eVb for the key reaction for solar neutrino production 7Be(p,γ)8B. We discuss a proposed use of the breakup of proton drip line nucleus 23Al to obtain the stellar reaction rate for 22Mg(p,γ)23Al. (author)

  7. Neutrino anomalies without oscillations

    Sandip Pakvasa

    2000-01-01

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

  8. Inverse Compton Scattering on Solar Photons, Heliospheric Modulation, and Neutrino Astrophysics

    Moskalenko, Igor V.; /Stanford U., HEPL; Porter, Troy A.; /UC, Santa Cruz; Digel, Seth W.; /SLAC

    2006-08-01

    We study the inverse Compton scattering of solar photons by Galactic cosmic-ray electrons. We show that the {gamma}-ray emission from this process is significant with the maximum flux in the direction of the Sun; the angular distribution of the emission is broad. This previously neglected foreground should be taken into account in studies of the diffuse Galactic and extragalactic {gamma}-ray emission. Furthermore, observations by GLAST can be used to monitor the heliosphere and determine the electron spectrum as a function of position from distances as large as Saturn's orbit down to close proximity of the Sun, thus enabling studies of solar modulation in the most extreme case. This paves the way for the determination of other Galactic cosmic-ray species, primarily protons, near the solar surface leading to accurate predictions of {gamma}-rays from pp-interactions in the solar atmosphere. These albedo {gamma}-rays will be observable by GLAST, allowing the study of deep atmospheric layers, magnetic field(s), and cosmic-ray cascade development. The latter is necessary to calculate the neutrino flux from pp-interactions at higher energies (>1 TeV). The corresponding neutrino flux from the Sun can be used as a ''standard candle'' for upcoming km{sup 3} neutrino detectors, such as IceCube. Since the solar core is opaque for very high-energy neutrinos, it may be possible to directly study the mass distribution of the Sun.

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

    Desai, Shantanu

    2016-01-01

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

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

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

    2015-01-01

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

  11. Neutrino 2004: Collection of Presentations

    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

  12. Neutrino 2004: Collection of Presentations

    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.

  13. Neutrino Physics with JUNO

    An, Fengpeng; An, Guangpeng; An, Qi; Antonelli, Vito; Baussan, Eric; Beacom, John; Bezrukov, Leonid; Blyth, Simon; Brugnera, Riccardo; Avanzini, Margherita Buizza; Busto, Jose; Cabrera, Anatael; Cai, Hao; Cai, Xiao; Cammi, Antonio

    2015-01-01

    The Jiangmen Underground Neutrino Observatory (JUNO), a 20 kton multi-purpose underground liquid scintillator detector, was proposed with the determination of the neutrino mass hierarchy as a primary physics goal. It is also capable of observing neutrinos from terrestrial and extra-terrestrial sources, including supernova burst neutrinos, diffuse supernova neutrino background, geoneutrinos, atmospheric neutrinos, solar neutrinos, as well as exotic searches such as nucleon decays, dark matter,...

  14. Measurement of Gamow-Teller strength for 127I as a solar neutrino detector

    Gamow-Teller transition strengths obtained in the 127I(p,n)127Xe reaction studied at 94, 159, and 197 MeV incident proton energies are presented, and used to evaluate the efficiency of 127I as a solar neutrino detector. Excitation of the Jπ=(3/2)+ first excited state at Ex=0.125 MeV in 127Xe, sensitive to 7Be solar neutrinos, is evaluated. The sum of Gamow-Teller strength up to particle emission threshold and up to 20 MeV excitation energy are also reported. This paper also provides a new measurement of the Coulomb displacement energy ΔEc, the excitation energy of the isobaric analog state, and the centroid of the Gamow-Teller resonance in 127Xe. copyright 1999 The American Physical Society

  15. Measurement of Gamow-Teller strength for {sup 127}I as a solar neutrino detector

    Palarczyk, M.; Rapaport, J.; Hautala, C. [Ohio University, Athens, Ohio 45701 (United States); Prout, D.L. [Department of Physics, Kent State University, Kent, Ohio 44242 (United States); Goodman, C.D.; van Heerden, I.J.; Sowinski, J.; Savopulos, G.; Yang, X. [Indiana University Cyclotron Facility, Bloomington, Indiana 47405 (United States); Sages, H.M.; Howes, R.; Carr, R.; Islam, M. [Ball State University, Muncie, Indiana 47306 (United States); Sugarbaker, E.; Cooper, D.C. [The Ohio State University, Columbus, Ohio 43210 (United States); Lande, K. [University of Pennsylvania, Philadelphia, Pennsylvania 19104 (United States); Luther, B. [Concordia College, Moorhead, Minnesota 56562 (United States); Taddeucci, T.N. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

    1999-01-01

    Gamow-Teller transition strengths obtained in the {sup 127}I(p,n){sup 127}Xe reaction studied at 94, 159, and 197 MeV incident proton energies are presented, and used to evaluate the efficiency of {sup 127}I as a solar neutrino detector. Excitation of the J{sup {pi}}=(3/2){sup +} first excited state at E{sub x}=0.125 MeV in {sup 127}Xe, sensitive to {sup 7}Be solar neutrinos, is evaluated. The sum of Gamow-Teller strength up to particle emission threshold and up to 20 MeV excitation energy are also reported. This paper also provides a new measurement of the Coulomb displacement energy {Delta}E{sub c}, the excitation energy of the isobaric analog state, and the centroid of the Gamow-Teller resonance in {sup 127}Xe. {copyright} {ital 1999} {ital The American Physical Society}

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

    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 → νbar nu, τ+τ-, bbar b, 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 νbar nu 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 νbar nu channel with the DM mass lighter than 6.5 GeV . If the νbar nu 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.

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

    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−,bb-bar, we take two sets of selection conditions to calculate the expected signals and atmospheric neutrino backgrounds based on the Monte Carlo simulation data. Then the JUNO sensitivities to the spin independent DM-nucleon and spin dependent DM-proton cross sections are presented. It is found that the JUNO projected sensitivities are much better than the current spin dependent direct detection experimental limits for the νν-bar and τ+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

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

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

    2016-01-21

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

  19. Radiochemical solar neutrino experiment using 81Br(nu, e-)81Kr

    Both geochemical and radiochemical experiments based on the interaction 81Br(nu,e-)81Kr to detect 7Be solar neutrinos have been suggested as a logical extension of the 37Cl experiment of Davis et al. The 81Br experiment, however, requires the development of a direct counter for the slowly decaying 81Kr. Progress toward such a detector based on Resonance Ionization Spectroscopy (RIS) is discussed

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

    Reggiani, N.; Guzzo, M. M.; Colonia, J. H.; de Holanda, P. C.

    1998-01-01

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

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

    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.)

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

    Lopes, Ilidio

    2013-01-01

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

  3. MSW Solutions to the Solar Neutrino Problem in Presence of Noisy Matter Density Fluctuations

    Bykov, A A; Peña-Garay, C; Popov, V Yu; Semikoz, V B

    2000-01-01

    We study the effect of random matter density fluctuations in the sun on resonant neutrino conversion in matter by solving numerically the evolution equation for the neutrino system including the full effect of the random matter density fluctuations of given amplitude and correlation length. In order to establish the possible effect on the MSW solutions to the solar neutrino problem we perform a global analysis of all the existing observables including the measured total rates as well as the Super-Kamiokande measurement on the time dependence of the event rates during the day and night and the recoil electron energy spectrum. We find the effects of random noise to be larger for small mixing angles and they are mostly important for correlation lengths in the range few 100 km $\\lesssim L_0\\lesssim$ few 1000 km. They can be understood as due to a parametric resonance occuring when the phase acquired by the oscillating neutrino state on one fluctuation length L_0 is a multiple of 2$\\pi$. We find that this resonant...

  4. Democratic neutrino mass matrix from generalized Fridberg-Lee model with the perturbative solar mass splitting

    Razzaghi, N

    2015-01-01

    We propose a phenomenological model of the Dirac neutrino mass matrix based on the Fridberg-Lee neutrino mass model at a special point. In this case, the Fridberg-Lee model reduces to the Democratic mass matrix with the $S_3$ permutation family symmetry. The Democratic mass matrix has an experimentally unfavored degenerate mass spectrum on the base of tribimaximal mixing matrix. We rescue the model to find a nondegenerate mass spectrum by adding the breaking mass term as preserving the twisted Fridberg-Lee symmetry. The tribimaximal mixing matrix can be also realized. Exact tribimaximal mixing leads to $\\theta_{13}=0$. However, the results from Daya Bay and RENO experiments have established a nonzero value for $\\theta_{13}$. Keeping the leading behavior of $U$ as tribimaximal, we use Broken Democratic neutrino mass model. We characterize a perturbation mass matrix which is responsible for a nonzero $\\theta_{13}$ along with CP violation, besides the solar neutrino mass splitting has been resulted from it. We c...

  5. 15 CFR 8b.16 - Discrimination prohibited.

    2010-01-01

    ... 15 Commerce and Foreign Trade 1 2010-01-01 2010-01-01 false Discrimination prohibited. 8b.16 Section 8b.16 Commerce and Foreign Trade Office of the Secretary of Commerce PROHIBITION OF DISCRIMINATION... Accessibility § 8b.16 Discrimination prohibited. No qualified handicapped individual shall, because a...

  6. 15 CFR 8b.11 - Discrimination prohibited.

    2010-01-01

    ... 15 Commerce and Foreign Trade 1 2010-01-01 2010-01-01 false Discrimination prohibited. 8b.11 Section 8b.11 Commerce and Foreign Trade Office of the Secretary of Commerce PROHIBITION OF DISCRIMINATION... Practices § 8b.11 Discrimination prohibited. (a) General. (1) No qualified handicapped individual shall,...

  7. 15 CFR 8b.4 - Discrimination prohibited.

    2010-01-01

    ... 15 Commerce and Foreign Trade 1 2010-01-01 2010-01-01 false Discrimination prohibited. 8b.4 Section 8b.4 Commerce and Foreign Trade Office of the Secretary of Commerce PROHIBITION OF DISCRIMINATION... Provisions § 8b.4 Discrimination prohibited. (a) General. No qualified handicapped individual shall, on...

  8. Thermal distributions in stellar plasmas, nuclear reactions and solar neutrinos

    Coraddu, M.; Kaniadakis, G.; A. Lavagno(Politecnico di Torino and INFN, Sezione di Torino, Torino Italy); Lissia, M.; Mezzorani, G.; P. Quarati

    1998-01-01

    The physics of nuclear reactions in stellar plasma is reviewed with special emphasis on the importance of the velocity distribution of ions. Then the properties (density and temperature) of the weak-coupled solar plasma are analysed, showing that the ion velocities should deviate from the Maxwellian distribution and could be better described by a weakly-nonexstensive (|q-1|

  9. A liquid argon time projection chamber for the solar neutrino problem

    The construction and successful test of a large liquid argon time projection chamber prototype detector is presented. This effort is a part of the ICARUS project which is aimed at the development of new detector techniques to uncover the very rare events like proton decay and solar neutrinos. The construction and test of this detector has been carried out at CERN from 1989 until the present time. The charge lifetime measured is 3.19 ± 0.13 ms. The authors also report on a precision measurement of lifetime by a laser monitoring chamber and the operation of the recirculation system essential to keeping liquid for a long time. They show that a liquid argon detector is very well suited to study mass-enhanced neutrino oscillation (MSW effect) from the Sun by detecting simultaneous two modes of reaction. Ratio of two modes provides a model independent probe of neutrino oscillation, free of deviations from different solar models. Contours plots are presented at various threshold energies

  10. a Liquid Argon Time Projection Chamber for the Solar Neutrino Problem

    Cheng, Mao-Tung

    The construction and successful test of a large liquid argon time projection chamber prototype detector is presented. This effort is a part of the ICARUS project which is aimed at the development of new detector techniques to uncover the very rare events like proton decay and solar neutrinos. The construction and test of this detector has been carried out at CERN from 1989 until the present time. The charge lifetime measured is 3.19 +/- 0.13 ms. We also report on a precision measurement of lifetime by a laser monitoring chamber and the operation of the recirculation system essential to keeping liquid for a long time. We show that a liquid argon detector is very well suited to study mass-enhanced neutrino oscillation (MSW effect) from the Sun by detecting simultaneous two modes of reaction. Ratio of two modes provides a model independent probe of neutrino oscillation, free of deviations from different solar models. Contour plots are presented at various threshold energies.

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

    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...

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

    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 4He 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

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

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

  14. Neutrino sunshine

    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

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

    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.

  16. Experimental Neutrino Physics

    Zuber, K.

    2008-01-01

    It's been a remarkable decade in neutrino physics. Ten years ago this summer, at the 1998 neutrino conference in Takayama, the Super-Kamiokande collaboration reported the observation of neutrinos changing flavor, thereby establishing the existence of neutrino mass. A few years later, the SNO experiment solved the long-standing solar neutrino problem demonstrating that it too was due to neutrino oscillation. Just a few years after that, these effects were confirmed and the oscillation paramete...

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

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

    2006-08-01

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

  18. Muons and Neutrinos 2007

    Gaisser, Thomas K

    2008-01-01

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

  19. 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)

    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)

  20. Earth regeneration of solar neutrinos at SNO and Super-Kamiokande

    We analyze the 1258-day Super-Kamiokande day and night solar neutrino energy spectra with various χ2 definitions. The best-fit lies in the large mixing angle (LMA) region at (Δm2,tan2θ)=(5.01 x 10-5 eV2,0.60), independently of whether systematic errors are included in the χ2 definition. We compare the exclusion and allowed regions from the different definitions and choose the most suitable definition to predict the regions from SNO at the end of three years of data accumulation. We first work under the assumption that Super-Kamiokande ''sees'' a flux-suppressed flat energy spectrum. Then, we consider the possibility of each one of the three Mikheyev-Smirnov-Wolfenstein regions being the solution to the solar neutrino problem. We find that the exclusion and allowed regions for the flat spectrum hypothesis and the LMA and low probability, low mass solutions are alike. In three years, we expect SNO to find very similar regions to that obtained by Super-Kamiokande. We evaluate whether the zenith angle distribution at SNO with optimum binning will add anything to the analysis of the day and night spectra; for comparison, we show the results of our analysis of the 1258-day zenith angle distribution from Super-Kamiokande, for which the best-fit parameters are (Δm2,tan2θ)=(5.01 x 10-5 eV2,0.56)

  1. Shedding light on LMA-Dark solar neutrino solution by medium baseline reactor experiments: JUNO and RENO-50

    Bakhti, Pouya

    2014-01-01

    In the presence of Non-Standard neutral current Interactions (NSI) a new solution to solar neutrino anomaly with $\\cos 2\\theta_{12}<0$ appears. We show that this solution can be tested by upcoming intermediate baseline reactor experiments JUNO and RENO-50.

  2. The Story of the Neutrino

    Rajasekaran, G

    2016-01-01

    This is an elementary review of the history and physics of neutrinos. The story of the discovery of neutrino mass through neutrino oscillations is described in some detail. Experiments on solar neutrinos and atmospheric neutrinos played an important part. Recent advances are summarized and future developments are indicated.

  3. The 8Li Calibration Source for the Sudbury Neutrino Obervatory

    Tagg, N. J.; Hamer, A; Sur, B.; Earle, E. D.; Helmer, R. L.; Jonkmans, G.; Moffat, B.A.; Simpson, J. J.

    2002-01-01

    A calibration source employing 8Li (t_1/2 = 0.838s) has been developed for use with the Sudbury Neutrino Observatory (SNO). This source creates a spectrum of beta particles with an energy range similar to that of the SNO 8B solar neutrino signal. The source is used to test the SNO detector's energy response, position reconstruction and data reduction algorithms. The 8Li isotope is created using a deuterium-tritium neutron generator in conjunction with a 11B target, and is carried to a decay c...

  4. Neutrino Mass Models

    King, S. F.

    2003-01-01

    This is a review article about neutrino mass models, particularly see-saw models involving three active neutrinos which are capable of describing both the atmospheric neutrino oscillation data, and the large mixing angle MSW solar solution, which is now uniquely specified by recent data. We briefly review the current experimental status, show how to parametrise and construct the neutrino mixing matrix, and present the leading order neutrino Majorana mass matrices. We then introduce the see-sa...

  5. Effects of sudden mixing in the solar core on solar neutrinos and ice ages.

    Ezer, D.; Cameron, A. G. W.

    1972-01-01

    Some numerical experiments with a solar model have been conducted in connection with the hypothesis regarding the effects of mixing in the solar core. Questions concerning a plausible mechanism by which such a mixing could be produced are explored. The variation of solar luminosity throughout the numerical experiments is shown. In connection with a great change in luminosity after a second mixing, it is suggested that the earth is presently undergoing an ice age.

  6. The photomultiplier tube calibration of the Sudbury Neutrino Observatory

    Cameron, J R N

    2001-01-01

    PMTs, and restores the time resolution to the extent possible. The PMT calibration also converts the integrated charge into the same units for all PMTs. This thesis describes how the PMT calibration is implemented and presents the results of investigations into its performance. The PMT calibration is found to perform well and is crucial to the analysis of SNO data. The Sudbury Neutrino Observatory (SNO) is a solar neutrino experiment designed to search for neutrino flavour oscillations. It is located 2040m underground in the INCO, Ltd. Creighton mine near Sudbury, Ontario. The detector consists of a kilotonne of heavy water (D sub 2 O) viewed by approximately 9,500 Photomultiplier Tubes (PMTs). The PMTs detect Cerenkov photons produced following the interactions of sup 8 B solar neutrinos with the D sub 2 O. These neutrinos can interact with D sub 2 O in three different ways. This allows the electron neutrino flux and the total flux of all flavours of neutrino to be measured. In order to distinguish the diffe...

  7. Ab initio many-body calculation of the 7Be(p,gamma)8B radiative capture

    Navratil, Petr; Quaglioni, Sofia

    2011-01-01

    We apply the ab initio no-core shell model/resonating group method (NCSM/RGM) approach to calculate the cross section of the 7Be(p,gamma)8B radiative capture. This reaction is important for understanding the solar neutrino flux. Starting from a selected similarity-transformed chiral nucleon-nucleon interaction that accurately describes two-nucleon data, we performed parameter-free many-body calculations that simultaneously predict both the normalization and the shape of the S-factor. We study the dependence on the number of 7Be eigenstates included in the coupled-channel equations and on the size of the harmonic oscillator basis used for the expansion of the eigenstates and of the localized parts of the integration kernels. Our S-factor result at zero energy is on the lower side of, but consistent with, the latest evaluation.

  8. Measurement of the response of a Ga solar neutrino experiment to 37Ar source

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

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

    Two 71Ga 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

  10. Low-energy neutrinos

    Ludhova, Livia

    2016-01-01

    There exist several kinds of sources emitting neutrinos in the MeV energy range. These low-energy neutrinos from different sources can be often detected by the same multipurpose detectors. The status-of-art of the feld of solar neutrinos, geoneutrinos, and the search for sterile neutrino with artifcial neutrino sources is provided here; other neutrino sources, as for example reactor or high-energy neutrinos, are described elsewhere. For each of these three felds, the present-day motivation an...

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

    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

  12. Low energy neutrino detection with the Mont Blanc LSD experiment

    A 90 tons Liquid Scintillation Detector (LSD) is fully running since October 1984 in the Mont Blanc Laboratory, at a depth of 5200 hg/cm2 under ground. The detection of cosmic neutrinos of different origin is the main goal of this experiment. The detector is very well shielded against the local radioactivity and is extremely sensitive to detect low energy particles with a threshold of 5 MeV. We discuss here the status of the experiment and present data on: 1) An experimental limit on the rate of neutrino bursts from galactic stellar collapses, 2) The possibility to detect solar neutrinos either from the 8B decay or correlated with large solar flares, and 3) An experimental limit on the flux of anti νe in the energy range 5 to 60 MeV. (orig.)

  13. Core-Collapse Supernovae from 9 to 120 Solar Masses Based on Neutrino-powered Explosions

    Sukhbold, Tuguldur; Woosley, S E; Brown, Justin M; Janka, H -T

    2015-01-01

    Nucleosynthesis, light curves, explosion energies, and remnant masses are calculated for a grid of supernovae resulting from massive stars with solar metallicity and masses from 9.0 to 120 solar masses. The full evolution is followed using an adaptive reaction network of up to 2000 nuclei. A novel aspect of the survey is the use of a one-dimensional neutrino transport model for the explosion. This explosion model has been calibrated to give the observed energy for SN 1987A, using several standard progenitors, and for the Crab supernova using a 9.6 solar mass progenitor. As a result of using a calibrated central engine, the final kinetic energy of the supernova is variable and sensitive to the structure of the presupernova star. Many progenitors with extended core structures do not explode, but become black holes, and the masses of exploding stars do not form a simply connected set. The resulting nucleosynthesis agrees reasonably well with the sun provided that a reasonable contribution from Type Ia supernovae...

  14. Neutrino Experiments and Their Implications

    Balantekin, A. B.

    2004-01-01

    Recent developments in solar, reactor, and accelerator neutrino physics are reviewed. Implications for neutrino physics, solar physics, nuclear two-body physics, and r-process nucleosynthesis are briefly discussed.

  15. The photomultiplier tube calibration of the Sudbury Neutrino Observatory

    The Sudbury Neutrino Observatory (SNO) is a solar neutrino experiment designed to search for neutrino flavour oscillations. It is located 2040m underground in the INCO, Ltd. Creighton mine near Sudbury, Ontario. The detector consists of a kilotonne of heavy water (D2O) viewed by approximately 9,500 Photomultiplier Tubes (PMTs). The PMTs detect Cerenkov photons produced following the interactions of 8B solar neutrinos with the D2O. These neutrinos can interact with D2O in three different ways. This allows the electron neutrino flux and the total flux of all flavours of neutrino to be measured. In order to distinguish the different types of reaction, it is essential to reconstruct where the interactions took place in the detector. The reconstruction critically depends on an accurate knowledge of the relative times at which the PMTs detect the Cerenkov photons. The first results from SNO provide strong evidence for neutrino oscillations and have further constrained the possible values of the square of the neutrino mass differences and the neutrino mixing angles. The topic of this thesis is the Photomultiplier Tube Calibration. The SNO electronics record a time and an integrated charge for each PMT that is triggered by a photon. The recorded time has an unknown offset and the time resolution of the PMTs is degraded by an effect arising from variations in the pulse sizes. The PMT calibration removes the time offsets, giving the relative timing of the PMTs, and restores the time resolution to the extent possible. The PMT calibration also converts the integrated charge into the same units for all PMTs. This thesis describes how the PMT calibration is implemented and presents the results of investigations into its performance. The PMT calibration is found to perform well and is crucial to the analysis of SNO data. (author)

  16. Sterile neutrinos

    Kopp, J.; Machado, P. A. N.; Maltoni, M.; Schwetz, T.

    2016-06-01

    We characterize statistically the indications of a presence of one or more light sterile neutrinos from MiniBooNE and LSND data, together with the reactor and gallium anomalies, in the global context. The compatibility of the aforementioned signals with null results from solar, atmospheric, reactor, and accelerator experiments is evaluated. We conclude that a severe tension is present in the global fit, and therefore the addition of eV-scale sterile neutrinos does not satisfactorily explain the anomalies.

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

    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 νe ↔ νμ,τ and νe ↔ νs cases. The physical causes of these differences are determined. (authors)

  18. Neutrino Physics with JUNO

    An, Fengpeng; An, Qi; Antonelli, Vito; Baussan, Eric; Beacom, John; Bezrukov, Leonid; Blyth, Simon; Brugnera, Riccardo; Avanzini, Margherita Buizza; Busto, Jose; Cabrera, Anatael; Cai, Hao; Cai, Xiao; Cammi, Antonio; Cao, Guofu; Cao, Jun; Chang, Yun; Chen, Shaomin; Chen, Shenjian; Chen, Yixue; Chiesa, Davide; Clemenza, Massimiliano; Clerbaux, Barbara; Conrad, Janet; D'Angelo, Davide; De Kerret, Herve; Deng, Zhi; Deng, Ziyan; Ding, Yayun; Djurcic, Zelimir; Dornic, Damien; Dracos, Marcos; Drapier, Olivier; Dusini, Stefano; Dye, Stephen; Enqvist, Timo; Fan, Donghua; Fang, Jian; Favart, Laurent; Ford, Richard; Goger-Neff, Marianne; Gan, Haonan; Garfagnini, Alberto; Giammarchi, Marco; Gonchar, Maxim; Gong, Guanghua; Gong, Hui; Gonin, Michel; Grassi, Marco; Grewing, Christian; Guan, Mengyun; Guarino, Vic; Guo, Gang; Guo, Wanlei; Guo, Xin-Heng; Hagner, Caren; Han, Ran; He, Miao; Heng, Yuekun; Hsiung, Yee; Hu, Jun; Hu, Shouyang; Hu, Tao; Huang, Hanxiong; Huang, Xingtao; Huo, Lei; Ioannisian, Ara; Jeitler, Manfred; Ji, Xiangdong; Jiang, Xiaoshan; Jollet, Cecile; Kang, Li; Karagounis, Michael; Kazarian, Narine; Krumshteyn, Zinovy; Kruth, Andre; Kuusiniemi, Pasi; Lachenmaier, Tobias; Leitner, Rupert; Li, Chao; Li, Jiaxing; Li, Weidong; Li, Weiguo; Li, Xiaomei; Li, Xiaonan; Li, Yi; Li, Yufeng; Li, Zhi-Bing; Liang, Hao; Lin, Guey-Lin; Lin, Tao; Lin, Yen-Hsun; Ling, Jiajie; Lippi, Ivano; Liu, Dawei; Liu, Hongbang; Liu, Hu; Liu, Jianglai; Liu, Jianli; Liu, Jinchang; Liu, Qian; Liu, Shubin; Liu, Shulin; Lombardi, Paolo; Long, Yongbing; Lu, Haoqi; Lu, Jiashu; Lu, Jingbin; Lu, Junguang; Lubsandorzhiev, Bayarto; Ludhova, Livia; Luo, Shu; Lyashuk, Vladimir; Mollenberg, Randolph; Ma, Xubo; Mantovani, Fabio; Mao, Yajun; Mari, Stefano M; McDonough, William F; Meng, Guang; Meregaglia, Anselmo; Meroni, Emanuela; Mezzetto, Mauro; Miramonti, Lino; Mueller, Thomas; Naumov, Dmitry; Oberauer, Lothar; Ochoa-Ricoux, Juan Pedro; Olshevskiy, Alexander; Ortica, Fausto; Paoloni, Alessandro; Peng, Haiping; Peng, Jen-Chieh; Previtali, Ezio; Qi, Ming; Qian, Sen; Qian, Xin; Qian, Yongzhong; Qin, Zhonghua; Raffelt, Georg; Ranucci, Gioacchino; Ricci, Barbara; Robens, Markus; Romani, Aldo; Ruan, Xiangdong; Ruan, Xichao; Salamanna, Giuseppe; Shaevitz, Mike; Sinev, Valery; Sirignano, Chiara; Sisti, Monica; Smirnov, Oleg; Soiron, Michael; Stahl, Achim; Stanco, Luca; Steinmann, Jochen; Sun, Xilei; Sun, Yongjie; Taichenachev, Dmitriy; Tang, Jian; Tkachev, Igor; Trzaska, Wladyslaw; van Waasen, Stefan; Volpe, Cristina; Vorobel, Vit; Votano, Lucia; Wang, Chung-Hsiang; Wang, Guoli; Wang, Hao; Wang, Meng; Wang, Ruiguang; Wang, Siguang; Wang, Wei; Wang, Yi; Wang, Yifang; Wang, Zhe; Wang, Zheng; Wang, Zhigang; Wang, Zhimin; Wei, Wei; Wen, Liangjian; Wiebusch, Christopher; Wonsak, Bjorn; Wu, Qun; Wulz, Claudia-Elisabeth; Wurm, Michael; Xi, Yufei; Xia, Dongmei; Xie, Yuguang; Xing, Zhi-zhong; Xu, Jilei; Yan, Baojun; Yang, Changgen; Yang, Chaowen; Yang, Guang; Yang, Lei; Yang, Yifan; Yao, Yu; Yegin, Ugur; Yermia, Frederic; You, Zhengyun; Yu, Boxiang; Yu, Chunxu; Yu, Zeyuan; Zavatarelli, Sandra; Zhan, Liang; Zhang, Chao; Zhang, Hong-Hao; Zhang, Jiawen; Zhang, Jingbo; Zhang, Qingmin; Zhang, Yu-Mei; Zhang, Zhenyu; Zhao, Zhenghua; Zheng, Yangheng; Zhong, Weili; Zhou, Guorong; Zhou, Jing; Zhou, Li; Zhou, Rong; Zhou, Shun; Zhou, Wenxiong; Zhou, Xiang; Zhou, Yeling; Zhou, Yufeng; Zou, Jiaheng

    2015-01-01

    The Jiangmen Underground Neutrino Observatory (JUNO), a 20 kton multi-purpose underground liquid scintillator detector, was proposed with the determination of the neutrino mass hierarchy as a primary physics goal. It is also capable of observing neutrinos from terrestrial and extra-terrestrial sources, including supernova burst neutrinos, diffuse supernova neutrino background, geoneutrinos, atmospheric neutrinos, solar neutrinos, as well as exotic searches such as nucleon decays, dark matter, sterile neutrinos, etc. We present the physics motivations and the anticipated performance of the JUNO detector for various proposed measurements. By detecting reactor antineutrinos from two power plants at 53-km distance, JUNO will determine the neutrino mass hierarchy at a 3-4 sigma significance with six years of running. The measurement of antineutrino spectrum will also lead to the precise determination of three out of the six oscillation parameters to an accuracy of better than 1\\%. Neutrino burst from a typical cor...

  19. KamLAND, solar antineutrinos and their magnetic moment

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

    2003-01-01

    We investigate the possibility of detecting solar antineutrinos with the KamLAND experiment. These antineutrinos are predicted by spin-flavor oscillations at a significant rate even if this mechanism is not the leading solution to the SNP. The recent evidence from SNO shows that a) the neutrino oscillates, only around 34% of the initial solar neutrinos arrive at the Earth as electron neutrinos and b) the conversion is mainly into active neutrinos, however a non e, mu, tau component is allowed: the fraction of oscillation into non-mu-tau neutrinos is found to be cos^2(alpha) = 0.08^{+0.20}_{-0.40}. This residual flux could include sterile neutrinos and/or the antineutrinos of the active flavors. KamLAND is potentially sensitive to antineutrinos derived from solar ^8 B neutrinos. In case of negative results, we find that KamLAND could put strict limits on the flux of solar antineutrinos, Phi(^8 B) < 1.0 times 10^4 cm^{-2} s^{-1}, more than one order of magnitude smaller than existing limits, and on their app...

  20. Microscopic nuclear-structure calculations for the solar-neutrino detector sup 7 sup 1 Ga and close-lying isobars

    Holmlund, E

    2003-01-01

    In the present solar-neutrino experiments, mainly observing the pp contribution of the solar-neutrino flux, an important role is played by sup 7 sup 1 Ga. The structure of this detector nucleus and three of its isobars have been calculated by using the microscopic quasiparticle-phonon model. Using a realistic effective two-body interaction in a realistic valence space, the method yielded energy spectra in good agreement with experiments. The calculated logft values for a number of spontaneous and neutrino-induced Gamow-Teller transitions, when compared with the experimental results, gave qualitatively correct but overestimated transition-strength values in most cases.

  1. The S(E) factor of 7Li(p,γ)8Be and consequences for S(E) extrapolation in 7Be(p,γ0)8B

    Excitation functions and forward-backward anisotropies have been measured for the 7Li(p, γ)8Be capture reaction over the proton energy range Ep = 100 to 1500 keV, using a 4π summing crystal and Ge(Li) detectors, respectively. The data show at all energies the presence of E1 and M1 capture amplitudes arising from the direct capture (DC) process and the ER = 441 and 1030 keV resonances, respectively. Due to the observed DC process, the present data increase significantly the reaction rates (up to a factor of 110) compared to values given in the compilation. The data and their analyses remove the recent criticism on DC model calculations, which had implied a significant reduction in the extrapolated S(E) factor for 7Be(p, γ)8B and thus in the predicted flux of high-energy solar neutrinos; thus, the solar neutrino problem is still with us. (orig.)

  2. 15 CFR 8b.13 - Employment criteria.

    2010-01-01

    ... job skills aptitude, or whatever factor the test purports to measure, rather than reflecting the... Practices § 8b.13 Employment criteria. (a) A recipient may not make use of any employment test or other... handicapped individuals unless; (1) The test score or other selection criterion, as used by the recipient,...

  3. 15 CFR 8b.25 - Nonacademic services.

    2010-01-01

    ... Secondary Education § 8b.25 Nonacademic services. (a) Physical education and athletics. (1) In providing physical education courses and athletics and similar aid, benefits, or services to any of its students, a... offers physical education courses or that operates or sponsors intercollegiate, club, or...

  4. New ways for real time detection of low energy solar neutrinos and other crucial experiments in nuclear and particle physics

    Real time solar neutrino detectors are an urgent need, and they must be sensitive to the pp part of the spectrum. Combining the simultaneous detection of light and phonons (the luminescent bolometer) with fast single crystal scintillators of InP and InSb compounds, very good background rejection can be achieved. Its applications in dark matter and double beta decay detection are discussed. (K.A.) 30 refs., 2 figs

  5. Excited States of 71Ge above the Neutron Emission Threshold and Solar Neutrino Capture rates for Ga Detectors

    Kar, Kamales; Sarkar, Sukhendusekhar; Goswami, Srubabati; Raychaudhuri, Amitava

    1997-01-01

    In Gallium detectors for solar neutrinos, the capture rate due to Gamow-Teller transitions to excited states of 71Ge beyond the neutron emission threshold is usually neglected. We make a model calculation to estimate its effect and find that this yields an additional contribution which may be as much as 0.4 SNU, even larger than that from the Isobaric Analog State in 71Ge reached by Fermi transitions, which is normally included in the standard predictions.

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

    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

  7. Democratic Neutrino Mixing Reexamined

    Fritzsch, Harald; Fritzsch, Harald; Xing, Zhi-zhong

    2004-01-01

    We reexamine the democratic neutrino mixing ansatz, in which the mass matrices of charged leptons and Majorana neutrinos arise respectively from the explicit breaking of S(3)_L x S(3)_R and S(3) flavor symmetries. It is shown that a democracy term in the neutrino sector can naturally allow the ansatz to fit the solar neutrino mixing angle \\theta_sun \\approx 33^\\circ. We predict \\sin^2 2\\theta_atm \\approx 0.95 for atmospheric neutrino mixing and J \\approx 1.2% for leptonic CP violation in neutrino oscillations without any fine-tuning. Direct relations between the model parameters and experimental observables are also discussed.

  8. The Sudbury Neutrino Observatory

    The Sudbury Neutrino Observatory is a second-generation water Cherenkov detector designed to determine whether the currently observed solar neutrino deficit is a result of neutrino oscillations. The detector is unique in its use of D2O as a detection medium, permitting it to make a solar model-independent test of the neutrino oscillation hypothesis by comparison of the charged- and neutral-current interaction rates. In this paper the physical properties, construction, and preliminary operation of the Sudbury Neutrino Observatory are described. Data and predicted operating parameters are provided whenever possible

  9. The Sudbury Neutrino Observatory

    Boger, J; Rowley, J K; Carter, A L; Hollebone, B; Kessler, D; Blevis, I; Dalnoki-Veress, F; De Kok, A; Farine, J; Grant, D R; Hargrove, C K; Laberge, G; Levine, I; McFarlane, K W; Mes, H; Noble, A T; Novikov, V M; O'Neill, M; Shatkay, M; Shewchuk, C; Sinclair, D; Clifford, E T H; Deal, R; Earle, E D; Gaudette, E; Milton, G; Sur, B; Bigu, J; Cowan, J H M; Cluff, D L; Hallman, E D; Haq, R U; Hewett, J L; Hykawy, J G; Jonkmans, G; Michaud, R; Roberge, A; Roberts, J; Saettler, E; Schwendener, M H; Seifert, H; Sweezey, D; Tafirout, R; Virtue, C J; Beck, D N; Chan, Y D; Chen, X; Dragowsky, M R; Dycus, F W; González, J; Isaac, M C P; Kajiyama, Y; Köhler, G W; Lesko, K T; Moebus, M C; Norman, E B; Okada, C E; Poon, A W P; Purgalis, P; Schülke, A; Smith, A R; Stokstad, R G; Turner, S; Zlimen, I; Anaya, J M; Bowles, T J; Brice, S J; Esch, E I; Fowler, M M; Goldschmidt, A; Hime, A; McGirt, A F; Miller, G G; Teasdale, W A; Wilhelmy, J B; Wouters, J M; Anglin, J D; Bercovitch, M; Davidson, W F; Storey, R S; Biller, S; Black, R A; Boardman, R J; Bowler, M G; Cameron, J; Cleveland, B; Ferraris, A P; Doucas, G; Heron, H; Howard, C; Jelley, N A; Knox, A B; Lay, M; Locke, W; Lyon, J; Majerus, S; Moorhead, M E; Omori, Mamoru; Tanner, N W; Taplin, R K; Thorman, M; Wark, D L; West, N; Barton, J C; Trent, P T; Kouzes, R; Lowry, M M; Bell, A L; Bonvin, E; Boulay, M; Dayon, M; Duncan, F; Erhardt, L S; Evans, H C; Ewan, G T; Ford, R; Hallin, A; Hamer, A; Hart, P M; Harvey, P J; Haslip, D; Hearns, C A W; Heaton, R; Hepburn, J D; Jillings, C J; Korpach, E P; Lee, H W; Leslie, J R; Liu, M Q; Mak, H B; McDonald, A B; MacArthur, J D; McLatchie, W; Moffat, B A; Noel, S; Radcliffe, T J; Robertson, B C; Skensved, P; Stevenson, R L; Zhu, X; Gil, S; Heise, J; Helmer, R L; Komar, R J; Nally, C W; Ng, H S; Waltham, C E; Allen, R C; Buhler, G; Chen, H H; Aardsma, G; Andersen, T; Cameron, K; Chon, M C; Hanson, R H; Jagam, P; Karn, J; Law, J; Ollerhead, R W; Simpson, J J; Tagg, N; Wang, J X; Alexander, C; Beier, E W; Cook, J C; Cowen, D F; Frank, E D; Frati, W; Keener, P T; Klein, J R; Mayers, G; McDonald, D S; Neubauer, M S; Newcomer, F M; Pearce, R J; Van de Water, R G; Van Berg, R; Wittich, P; Ahmad, Q R; Beck, J M; Browne, M C; Burritt, T H; Doe, P J; Duba, C A; Elliott, S R; Franklin, J E; Germani, J V; Green, P; Hamian, A A; Heeger, K M; Howe, M; Meijer-Drees, R; Myers, A; Robertson, R G H; Smith, M W E; Steiger, T D; Van Wechel, T; Wilkerson, J F

    2000-01-01

    The Sudbury Neutrino Observatory is a second generation water Cherenkov detector designed to determine whether the currently observed solar neutrino deficit is a result of neutrino oscillations. The detector is unique in its use of D2O as a detection medium, permitting it to make a solar model-independent test of the neutrino oscillation hypothesis by comparison of the charged- and neutral-current interaction rates. In this paper the physical properties, construction, and preliminary operation of the Sudbury Neutrino Observatory are described. Data and predicted operating parameters are provided whenever possible.

  10. Summary: Neutrinos and nonaccelerator physics

    This paper contains brief synopsis of the following major topics discussed in the neutrino and nonaccelerator parallel sessions: dark matter; neutrino oscillations at accelerators and reactors; gamma-ray astronomy; double beta decay; solar neutrinos; and the possible existence of a 17-KeV neutrino

  11. Neutrino oscillations and dark matter

    Zuber, K.

    1996-01-01

    The significance of light massive neutrinos as hot dark matter is outlined. The power of neutrino oscillation experiments with respect to detect such neutrinos in the eV-region is discussed. Present hints for neutrino oscillations in solar, atmospheric and LSND data are reviewed as well as future experiments and their potential.

  12. Neutrino Oscillation Studies with Reactors

    Vogel, Petr; Zhang, Chao

    2015-01-01

    Nuclear reactors are one of the most intense, pure, controllable, cost-effective, and well-understood sources of neutrinos. Reactors have played a major role in the study of neutrino oscillations, a phenomenon that indicates that neutrinos have mass and that neutrino flavors are quantum mechanical mixtures. Over the past several decades reactors were used in the discovery of neutrinos, were crucial in solving the solar neutrino puzzle, and allowed the determination of the smallest mixing angle $\\theta_{13}$. In the near future, reactors will help to determine the neutrino mass hierarchy and to solve the puzzling issue of sterile neutrinos.

  13. Neutrinos Mass and Mixing

    González-Garciá, M Concepción

    1998-01-01

    I review the status of neutrino masses and mixings in the light of the solar and atmospheric neutrino data. The result from the LSND experiment and the possible role of neutrinos as hot dark matter are also included. I also discuss the simplest schemes proposed to reconcile these data which include a light sterile neutrino in addition to the three standard ones. Implications for future experiments are commented.

  14. Status of Neutrino Oscillations

    J.W.F. Valle

    2001-01-01

    Solar and atmospheric neutrino data require physics beyond the Standard Model of particle physics. The simplest, most generic, but not yet unique, interpretation of the data is in terms of neutrino oscillations. I summarize the results of the latest three-neutrino oscillation global fit of the data, in particular the bounds on the angle $\\theta_{13}$ probed in reactor experiments. Even though not implied by the data, bi-maximal neutrino mixing emerges as an attractive possibility either in hi...

  15. Neutrino Sources and Properties

    Vissani, Francesco

    2014-01-01

    In this lecture, prepared for PhD students, basic considerations on neutrino interactions, properties and sites of production are overviewed. The detailed content is as follows: Sect. 1, Weak interactions and neutrinos: Fermi coupling; definition of neutrinos; global numbers. Sect. 2, A list of neutrino sources: Explanatory note and examples (solar pp- and supernova-neutrinos). Sect. 3, Neutrinos oscillations: Basic formalism (Pontecorvo); matter effect (Mikheev, Smirnov, Wolfenstein); status of neutrino masses and mixings. Sect. 4, Modifying the standard model to include neutrinos masses: The fermions of the standard model; one additional operator in the standard model (Weinberg); implications. One summary table and several exercises offer the students occasions to check, consolidate and extend their understanding; the brief reference list includes historical and review papers and some entry points to active research in neutrino physics.

  16. Prototype scintillator cell for an In-based solar neutrino detector

    Motta, D; Hartmann, F X; Lasserre, T; Schönert, S; Schwan, U; Motta, Dario; Buck, Christian; Hartmann, Francis Xavier; Lasserre, Thierry; Sch\\"{o}nert, Stefan; Schwan, Ute

    2005-01-01

    We describe the work carried out at MPIK to design, model, build and characterize a prototype cell filled with a novel indium-loaded scintillator of interest for real-time low energy solar neutrino spectroscopy. First, light propagation in optical modules was studied with experiments and Monte Carlo simulations. Subsequently a 5 cm x 5 cm x 100 cm prototype detector was set up and the optical performances of several samples were measured. We first tested a benchmark PXE-based scintillator, which performed an attenuation length of ~ 4.2 m and a photo-electron yield of ~ 730 pe/MeV. Then we measured three In-loaded samples. At an In-loading of 44 g/l, an energy resolution of ~ 11.6 % and a spatial resolution of ~ 7 cm were attained for 477 keV recoil electrons. The long-range attenuation length in the cell was ~1.3 m and the estimated photo-electron yield ~ 200 pe/MeV. Light attenuation and relative light output of all tested samples could be reproduced reasonably well by MC. All optical properties of this syst...

  17. Design Constraints for a WIMP Dark Matter and pp Solar Neutrino Liquid Neon Scintillation Detector

    Boulay, M G; Lidgard, J

    2004-01-01

    Detailed Monte-Carlo simulations were used to evaluate the performance of a liquid neon scintillation detector for dark matter and low-energy solar neutrino interactions. A maximum-likelihood event vertex fitter including PMT time information was developed, which significantly improves position resolution over spatial-only algorithms, and substantially decreases the required detector size and achievable analysis energy threshold. The ultimate sensitivity to WIMP dark matter and the pp flux uncertainty are evaluated as a function of detector size. The dependence on the neon scintillation and PMT properties are evaluated. A 300 cm radius detector would allow a ~13 keV threshold, a pp flux uncertainty of ~1%, and limits on the spin-independent WIMP-nucleon cross-section of ~10^{-46} cm^2 for a 100 GeV WIMP, using commercially available PMTs. Detector response calibration and background requirements for a precision pp measurement are defined. Internal radioactivity requirements for uranium, thorium, and krypton a...

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

    ,

    2011-01-01

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

  19. Workshop on low energy neutrino physics

    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

  20. Global analyses of neutrino oscillation experiments

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

    2016-07-01

    We summarize the determination of some neutrino properties from the global analysis of solar, atmospheric, reactor, and accelerator neutrino data in the framework of three-neutrino mixing as well as in some extended scenarios such as the mixing with eV-scale sterile neutrinos invoked for the interpretation of the short baseline anomalies, and the presence of non-standard neutrino interactions.

  1. First observation of beryllium-7 solar neutrinos with KamLAND

    Keefer, Gregory J.

    2009-09-01

    The international KamLAND collaboration operates a 1 kton liquid scintillation detector in the Kamioka mine in Gifu, Japan. KamLAND's main scientific results are the precision measurement of the solar Dm 2 12 = 7.58[Special characters omitted.] (stat) [Special characters omitted.] (syst) and tan 2 [straight theta] 12 = 0.56[Special characters omitted.] (stat) [Special characters omitted.] (syst) utilizing reactor n e and first evidence for the observation of geologically produced anti-neutrinos. In an effort to extend KamLAND's scientific reach, extensive research has been performed on preparing a spectroscopic measurement of 7 Be solar n e s. This work provides the first inclusive analysis of KamLAND's backgrounds below 1 MeV. 85 Kr and 210 Pb, dissolved in KamLAND liquid scintillator, were found to be the dominant source of low energy backgrounds. The concentration of these ultra-trace contaminants were determined to be 10 -20 g/g. This is more than 6 orders of magnitude lower than commercially available ultra-pure liquids. To attain a signal-to-background ratio suitable for the detection of 7 Be solar n e s, the concentration of these contaminants had to be reduced by 5 orders of magnitude. A comprehensive study of 210 Pb removal was undertaken over the course of this thesis. This work further covers techniques for the removal of 220 Rn, 222 Rn and their daughter nuclei from liquid scintillator at concentrations of 10^-18 g/g. Purification techniques studied in this work include water extraction, isotope exchange, adsorption, and distillation. These laboratory studies guided the design and implementation of a large scale purification system in the Kamioka mine. The purification system's design and operation is discussed in detail as well as specific experiments devised to control scintillator quality and radio-purity. The purification system's effectiveness in removing radioactive trace impurities is analyzed in detail. The total scintillator purified over two

  2. 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

    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.)

  3. Minimalistic Neutrino Mass Model

    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.

  4. Neutrino anomaly and -nucleus interactions

    S K Singh

    2001-08-01

    A review of various calculations of the inclusive quasi-elastic reactions and pion production processes in neutrino reactions for various nuclei at intermediate energies relevant to solar, atmospheric and accelerator neutrinos is presented.

  5. The LENA neutrino observatory

    LENA (Low Energy Neutrino Astronomy) is a future 50 kt liquid scintillator detector. The project is currently in its design phase and is part of the European LAGUNA-LBNO design study. Due to its low energy threshold, high energy resolution and good background discrimination capabilities, LENA features a very rich physics program for neutrinos with energies below 50 MeV. The high target mass will allow to study geoneutrinos and solar neutrinos with unreached statistics. Furthermore, in case of a supernova in our Galaxy, LENA will provide an energy, time and flavor resolved analysis of the neutrino pulse. It is also sensitive to the diffuse supernova neutrino background. Additionally, LENA is big enough to study GeV neutrinos like atmospheric neutrinos or neutrinos from a long distance beam. Due to its large mass, LENA can also search for the proton decay.

  6. Accelerator studies of neutrino oscillations

    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...

  7. Solar r-process-constrained actinide production in neutrino-driven winds of supernovae

    Goriely, S.; Janka, H.-Th.

    2016-04-01

    Long-lived radioactive nuclei play an important role as nucleo-cosmochronometers and as cosmic tracers of nucleosynthetic source activity. In particular nuclei in the actinide region like thorium, uranium, and plutonium can testify to the enrichment of an environment by the still enigmatic astrophysical sources that are responsible for the production of neutron-rich nuclei by the rapid neutron-capture process (r-process). Supernovae and merging neutron-star (NS) or NS-black hole binaries are considered as most likely sources of the r-nuclei. But arguments in favour of one or the other or both are indirect and make use of assumptions; they are based on theoretical models with remaining simplifications and shortcomings. An unambiguous observational determination of a production event is still missing. In order to facilitate searches in this direction, e.g. by looking for radioactive tracers in stellar envelopes, the interstellar medium or terrestrial reservoirs, we provide improved theoretical estimates and corresponding uncertainty ranges for the actinide production (232Th, 235, 236, 238U, 237Np, 244Pu, and 247Cm) in neutrino-driven winds of core-collapse supernovae. Since state-of-the-art supernova models do not yield r-process viable conditions -but still lack, for example, the effects of strong magnetic fields- we base our investigation on a simple analytical, Newtonian, adiabatic and steady-state wind model and consider the superposition of a large number of contributing components, whose nucleosynthesis-relevant parameters (mass weight, entropy, expansion time scale, and neutron excess) are constrained by the assumption that the integrated wind nucleosynthesis closely reproduces the solar system distribution of r-process elements. We also test the influence of uncertain nuclear physics.

  8. Solar r-process-constrained actinide production in neutrino-driven winds of supernovae

    Goriely, S.; Janka, H.-Th.

    2016-07-01

    Long-lived radioactive nuclei play an important role as nucleo-cosmochronometers and as cosmic tracers of nucleosynthetic source activity. In particular, nuclei in the actinide region like thorium, uranium, and plutonium can testify to the enrichment of an environment by the still enigmatic astrophysical sources that are responsible for the production of neutron-rich nuclei by the rapid neutron-capture process (r-process). Supernovae and merging neutron-star (NS) or NS-black hole binaries are considered as most likely sources of the r-nuclei. But arguments in favour of one or the other or both are indirect and make use of assumptions; they are based on theoretical models with remaining simplifications and shortcomings. An unambiguous observational determination of a production event is still missing. In order to facilitate searches in this direction, e.g. by looking for radioactive tracers in stellar envelopes, the interstellar medium or terrestrial reservoirs, we provide improved theoretical estimates and corresponding uncertainty ranges for the actinide production (232Th, 235, 236, 238U, 237Np, 244Pu, and 247Cm) in neutrino-driven winds of core-collapse supernovae. Since state-of-the-art supernova models do not yield r-process viable conditions - but still lack, for example, the effects of strong magnetic fields - we base our investigation on a simple analytical, Newtonian, adiabatic and steady-state wind model and consider the superposition of a large number of contributing components, whose nucleosynthesis-relevant parameters (mass weight, entropy, expansion time-scale, and neutron excess) are constrained by the assumption that the integrated wind nucleosynthesis closely reproduces the Solar system distribution of r-process elements. We also test the influence of uncertain nuclear physics.

  9. Shedding light on LMA-dark solar neutrino solution by medium baseline reactor experiments: JUNO and RENO-50

    Bakhti, P.; Farzan, Y.

    2014-07-01

    In the presence of Non-Standard neutral current Interactions (NSI) a new solution to solar neutrino anomaly with cos 2 θ 12 < 0 appears. We investigate how this solution can be tested by upcoming intermediate baseline reactor experiments, JUNO and RENO-50. We point out a degeneracy between the two solutions when both hierarchy and the θ 12 octant are flipped. We then comment on how this degeneracy can be partially lifted by long baseline experiments sensitive to matter effects such as the NOvA experiment.

  10. Long-Baseline Neutrino Experiments

    Diwan, M V; Qian, X; Rubbia, A

    2016-01-01

    We review long-baseline neutrino experiments in which neutrinos are detected after traversing macroscopic distances. Over such distances neutrinos have been found to oscillate among flavor states. Experiments with solar, atmospheric, reactor, and accelerator neutrinos have resulted in a coherent picture of neutrino masses and mixing of the three known flavor states. We will summarize the current best knowledge of neutrino parameters and phenomenology with our focus on the evolution of the experimental technique. We proceed from the first evidence produced by astrophysical neutrino sources to the current open questions and the goals of future research.

  11. The status of the Soviet-American gallium solar neutrino experiment

    Gavrin, V.N.; Abazov, A.I.; Abdurashitov, D.N.; Bowles, T.J.; Cleveland, B.T.; Elliott, S.R.; Davis, R. Jr.; Lande, K.; Cherry, M.L.; Kouzes, R.T.

    1989-01-01

    A radiochemical /sup 71/Ga--/sup 71/Ge experiment to determine the integral flux of neutrinos from the sun has been constructed at the Baksan Neutrino Observatory in the USSR. Measurements have begun with 30 tonnes of gallium. An additional 30 tonnes of gallium are being installed so as to perform the full experiment with a 60-tonne target. The motivation, experimental procedures, and present status of this experiment are described.

  12. NEUTRINO CHARGE WITH ITS GAUGE FIELD AS A NEW PHYSICAL BASE FOR NEW MODELS OF SOLAR ACTIVITY AND THE ALL TOTALITY OF PHENOMENA ASSOCIATED WITH SUPERNOVAE EXPLOSIONS, FORMING OF PULSARS AND THEIR FOLLOWING EVOLUTION

    KOPYSOV YU.S.

    2013-01-01

    The neutrino charge with its gauge field introduced in [Kopysov Yu. S., Stozhkov Yu. I., Korolkov D. N. (2001)] for the purpose of decreasing counting rates in solar neutrino detectors generates a lot of new phenomena in astrophysical objects. The physics of the new phenomena is determined by the value of the neutrino charge eν which carriers are neutrinos, quarks and neutrons, and also by almost degenerate neutrino condensate in substance of macroscopic objects. It is shown that the strongest...

  13. Sudbury neutrino observatory proposal

    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

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

    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.

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

    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

  16. Parametric resonance in neutrino oscillations in matter

    E Kh Akhmedov

    2000-01-01

    Neutrino oscillations in matter can exhibit a specific resonance enhancement - parametric resonance, which is different from the MSW resonance. Oscillations of atmospheric and solar neutrinos inside the earth can undergo parametric enhancement when neutrino trajectories cross the core of the earth. In this paper we review the parametric resonance of neutrino oscillations in matter. In particular, physical interpretation of the effect and the prospects of its experimental observation in oscillations of solar and atmospheric neutrinos in the earth are discussed.

  17. Detection of low energy solar neutrinos by a two-phase cryogenic e-bubble detector

    2007-01-01

    A new two-phase cryogenic neutrino detector using electron bubble (e-bubble) specifically in liquid helium is proposed and being developed for real time, high rate measurements of low-energy p-p reaction neutrinos from the sun. The e-bubble detector is a time projection chamber-like (TPC) tracking detector. The task of such a neutrino detector is to detect the ionization of the elastically scattered target electrons by incident neutrinos, and then to characterize their energy and direction and to distinguish them from radioactive backgrounds. The ionization signals are expected to be small and hence undergo avalanche amplification in the saturated vapor above the liquid phase by gas electron multipliers (GEMs) at high gain. Higher granularity and intrinsically suppressed ion feedback give a good spatial resolution and are the major advantages of this technology. It should be possible to construct such a detector to track charged particles down to 100―200 keV in a massive liquid helium target with fractional millimeter spatial resolution in three-dimensional space, using the GEM-based TPC with a high-resolution CCD camera, for both the electronic and light readout.

  18. Search for Cold Dark Matter and Solar Neutrinos with GENIUS and GENIUS-TF

    Krivosheina, I. V.

    2002-01-01

    Comment: 4 pages, revtex, 3 figures, Talk was presented at International School on Nuclear Physics, 23rd Course: Neutrinos in Astro, Particle and Nuclear Physics, Erice, September 18 - 26, 2001, Publ. in Progress in Particle and Nuclear Physics, Vol. 48 (2002) 283 - 286, Home Page of Heidelberg Non-Accelerator Particle Physics Group: http://www.mpi-hd.mpg.de/non_acc/

  19. Toward observational neutrino astrophysics

    This paper reviews experimental facilities of solar neutrinos and cosmology. The two experiments were both conceived to search for proton decay. These experiments and theories of particles are briefly reviewed.The first observation of the neutrino burst from the supernova SN 1987A are discussed

  20. Neutrino masses From fantasy to facts

    Valle, José W F

    1999-01-01

    Theory suggests the existence of neutrino masses, but little more. Facts are coming close to reveal our fantasy: solar and atmospheric neutrino data strongly indicate the need for neutrino conversions, while LSND provides an intriguing hint. The simplest ways to reconcile these data in terms of neutrino oscillations invoke a light sterile neutrino in addition to the three active ones. Out of the four neutrinos, two are maximally-mixed and lie at the LSND scale, while the others are at the solar mass scale. These schemes can be distinguished at neutral-current-sensitive solar & atmospheric neutrino experiments. I discuss the simplest theoretical scenarios, where the lightness of the sterile neutrino, the nearly maximal atmospheric neutrino mixing, and the generation of $\\Delta {m^2}_\\odot$ & $\\Delta {m^2}_{atm}$ all follow naturally from the assumed lepton-number symmetry and its breaking. Although the most likely interpretation of the present data is in terms of neutrino-mass-induced oscillations, one...

  1. Neutrino Masses, where do we stand?

    Valle, José W F

    1999-01-01

    I review the status of neutrino physics post-Neutrino~98, including the implications of solar and atmospheric neutrino data, which strongly indicate nonzero neutrino masses. LSND and the possible role of neutrinos as hot dark matter (HDM) are also mentioned. The simplest schemes proposed to reconcile these requirements invoke a light sterile neutrino in addition to the three active ones, two of them at the MSW scale and the other two maximally-mixed neutrinos at the HDM/LSND scale. In the simplest theory the latter scale arises at one-loop, while the solar and atmospheric parameters $\\Delta {m^2}_\\odot$ & neutrino, the nearly maximal atmospheric neutrino mixing, and the generation of lepton-number symmetry and its breaking. These two basic schemes can be distinguished at future solar & atmospheric neutrino experiments and have different cosmological implications.

  2. Nuclear-spectroscopic measurements related to the design of 79Br, 81Br, and 87Rb solar-neutrino detectors

    Spectroscopic properties for low-lying states in 79Kr, 81Kr, and 87Sr were studied using the 78Kr(dvector,p)79Kr, 80Kr(dvector,p)81Kr, and 86Sr(dvector,p)87Sr reactions initiated by 11 MeV purely vector-polarized deuteron beams at Triangle Universities Nuclear Laboratory. A Distorted-Wave Born Approximation analysis of the resulting angular distributions of cross section and vector analyzing power enabled the assignment of spin-parity and extraction of neutron spectroscopic factors for 48 nuclear states. A technique for preparation of thin targets using ion implantation was developed as a means to improve spectrum resolution by reducing projectile straggling in the entrance and exit foils of gas cell targets. The neutrino capture process, sigma + (Z,A) → (Z + 1,A) + e-, is equivalent to inverse beta decay. In order to interpret the results of a solar neutrino experiment using 79Br, 81Br, or 87Rb, low-lying states in the daughter nuclei, 79Kr, 81Kr, and 87Sr, must be studied. In particular, the states in the daughter nuclei that have appropriate spin-parity to be populated by allowed inverse beta decay must be identified

  3. Jiangmen Underground Neutrino Observatory: Status and Prospectives

    Li, Yu-Feng

    2016-01-01

    The Jiangmen Underground Neutrino Observatory (JUNO) is a 20 kton liquid scintillator (LS) detector, which is planed to determine the neutrino mass hierarchy and measure the oscillation parameters at the sub-percent level using reactor antineutrino oscillations. As a multipurpose neutrino experiment, JUNO is also capable of measuring supernova burst neutrinos, the diffuse supernova neutrino background, geo-neutrinos, solar neutrinos and atmospheric neutrinos. After a brief introduction to the physics motivation, we discuss the status of the JUNO project, including the design of the detector systems. Finally the latest civil progress and future prospectives are also highlighted.

  4. Phenomenology of neutrino oscillations

    G Rajasekaran

    2000-07-01

    The phenomenology of solar, atmospheric, supernova and laboratory neutrino oscillations is described. Analytical formulae for matter effects are reviewed. The results from oscillations are confronted with neutrinoless double beta decay.

  5. On a Generalized Entropy Measure Leading to the Pathway Model with a Preliminary Application to Solar Neutrino Data

    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.

  6. Zenith angle distributions at Super-Kamiokande and SNO and the solution of the solar neutrino problem

    González-Garciá, M Concepción; Smirnov, Yu A

    2001-01-01

    We have performed a detailed study of the zenith angle dependence of the regeneration factor and distributions of events at SNO and SK for different solutions of the solar neutrino problem. In particular, we discuss oscillatory behaviour and the synchronization effect in the distribution for the LMA solution, the parametric peak for the LOW solution, etc.. Physical interpretation of the effects is given. We suggest a new binning of events which emphasizes distinctive features of zenith angle distributions for the different solutions. We also find the correlations between the integrated day-night asymmetry and the rates of events in different zenith angle bins. Study of these correlations strengthens the identification power of the analysis.

  7. JUNO: a General Purpose Experiment for Neutrino Physics

    Grassi, Marco

    2016-01-01

    JUNO is a 20 kt Liquid Scintillator Antineutrino Detector currently under construction in the south of China. This report reviews JUNO's physics programme related to all neutrino sources but reactor antineutrinos, namely neutrinos from supernova burst, solar neutrinos and geoneutrinos.

  8. The 8Li Calibration Source for the Sudbury Neutrino Obervatory

    Tagg, N J; Sur, B; Earle, E D; Helmer, R L; Jonkmans, G; Moffat, B A; Simpson, J J

    2002-01-01

    A calibration source employing 8Li (t_1/2 = 0.838s) has been developed for use with the Sudbury Neutrino Observatory (SNO). This source creates a spectrum of beta particles with an energy range similar to that of the SNO 8B solar neutrino signal. The source is used to test the SNO detector's energy response, position reconstruction and data reduction algorithms. The 8Li isotope is created using a deuterium-tritium neutron generator in conjunction with a 11B target, and is carried to a decay chamber using a gas/aerosol transport system. The decay chamber detects prompt alpha particles by gas scintillation in coincidence with the beta particles which exit through a thin stainless steel wall. A description is given of the production, transport, and tagging techniques along with a discussion of the performance and application of the source.

  9. Jiangmen Underground Neutrino Observatory

    He, Miao

    2014-01-01

    The Jiangmen Underground Neutrino Observatory (JUNO) is a multipurpose neutrino-oscillation experiment designed to determine the neutrino mass hierarchy and to precisely measure oscillation parameters by detecting reactor antineutrinos, observe supernova neutrinos, study the atmospheric, solar neutrinos and geo-neutrinos, and perform exotic searches, with a 20 kiloton liquid scintillator detector of unprecedented $3\\%$ energy resolution (at 1 MeV) at 700-meter deep underground and to have other rich scientific possibilities. Currently MC study shows a sensitivity of the mass hierarchy to be $\\overline{\\Delta\\chi^2}\\sim 11$ and $\\overline{\\Delta\\chi^2}\\sim 16$ in a relative and an absolute measurement, respectively. JUNO has been approved by Chinese Academy of Sciences in 2013, and an international collaboration was established in 2014. The civil construction is in preparation and the R$\\&$D of the detectors are ongoing. A new offline software framework was developed for the detector simulation, the event ...

  10. Neutrinos, atoms and gravity

    A interesting overview of ongoing developments in neutrino physics and recent advances in atomic and optical physics and in gravitation emerged from the recent 'Moriond' Workshop on Perspectives in Neutrinos, Atomic Physics and Gravitation Theory, held from January 30 to February 6 at Villars sur Ollon in the Swiss Alps. Neutrino physics is a Moriond tradition, and the Workshop began with presentations of new measurements of the tritium beta spectrum by the Livermore and Mainz groups, setting limits on the mass of electron (anti)neutrino of 8 eV and 7.2 eV respectively. It is puzzling that the five most advanced experiments setting upper limits on the electron (anti)neutrino mass (Livermore, Los Alamos, Mainz, Tokyo and Zurich) report negative best-fit values for the square of the neutrino mass, with a weighted average of -59 ±177 ± 26 eV2. This corresponds to an excess of counts near the tritium endpoint, rather than a deficit which would indicate a nonzero neutrino mass. Gerry Stephenson presented a possible explanation, invoking a very light (or massless) scalar boson coupled only to neutrinos. Perhaps more plausibly, a systematic effect may be the cause, and further studies are underway. Nonetheless, the limits are unlikely to change significantly, and the results exclude electron neutrinos as the possible dominant component of dark matter. The solar neutrino problem persists

  11. Solar fusion cross sections II: the pp chain and CNO cycles

    Adelberger, E G; Bemmerer, D; Bertulani, C A; Chen, J -W; Costantini, H; Couder, M; Cyburt, R; Davids, B; Freedman, S J; Gai, M; Garcia, A; Gazit, D; Gialanella, L; Greife, U; Hass, M; Heeger, K; Haxton, W C; Imbriani, G; Itahashi, T; Junghans, A; Kubodera, K; Langanke, K; Leitner, D; Leitner, M; Marcucci, L E; Motobayashi, T; Mukhamedzhanov, A; Nollett, Kenneth M; Nunes, F M; Park, T -S; Parker, P D; Prati, P; Ramsey-Musolf, M J; Hamish Robertson, R G; Schiavilla, R; Simpson, E C; Snover, K A; Spitaleri, C; Strieder, F; Suemmerer, K; Trautvetter, R E; Tribble, R E; Typel, S; Uberseder, E; Vetter, P; Wiescher, M

    2011-04-01

    The available data on nuclear fusion cross sections important to energy generation in the Sun and other hydrogen-burning stars and to solar neutrino production are summarized and critically evaluated. Recommended values and uncertainties are provided for key cross sections, and a recommended spectrum is given for 8B solar neutrinos. Opportunities for further increasing the precision of key rates are also discussed, including new facilities, new experimental techniques, and improvements in theory. This review, which summarizes the conclusions of a workshop held at the Institute for Nuclear Theory, Seattle, in January 2009, is intended as a 10-year update and supplement to 1998, Rev. Mod. Phys. 70, 1265.

  12. Progress in neutrino oscillation searches and their implications

    Srubabati Goswami

    2003-02-01

    Neutrino oscillation, in which a given flavor of neutrino transforms into another is a powerful tool for probing small neutrino masses. The intrinsic neutrino properties involved are neutrino mass squared difference 2 and the mixing angle in vacuum . In this paper I will summarize the progress that we have achieved in our search for neutrino oscillation with special emphasis on the recent results from the Sudbury Neutrino Observatory (SNO) on the measurement of solar neutrino fluxes. I will outline the current bounds on the neutrino masses and mixing parameters and discuss the major physics goals of future neutrino experiments in the context of the present picture.

  13. Sudbury Neutrino Observatory

    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 Jan. 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 Cl-37 and Ga-71 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.

  14. The Sensitivity of a Lithium Experiment on Solar Neutrinos to the Mixing Angle theta_{12}

    Kopylov, Anatoly; Petukhov, Valery

    2003-01-01

    A lithium-based radiochemical detector is aimed primarily to detect neutrinos from CNO cycle what will provide a direct proof of its existence and will be a stringent test of the theory of stellar evolution. Another task which can be solved by this experiment is to measure a mixing angle $\\theta_{12}$. The sensitivity of a lithium experiment to $\\theta_{12}$ was calculated by Monte-Carlo following the proposed original technique which can be used as a complimentary one to a chi-square techniq...

  15. A Search for Astrophysical Burst Signals at the Sudbury Neutrino Observatory

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

    2013-01-01

    The Sudbury Neutrino Observatory (SNO) has confirmed the standard solar model and neutrino oscillations through the observation of neutrinos from the solar core. In this paper we present a search for neutrinos associated with sources other than the solar core, such as gamma-ray bursters and solar flares. We present a new method for looking for temporal coincidences between neutrino events and astrophysical bursts of widely varying intensity. No correlations were found between neutrinos detected in SNO and such astrophysical sources.

  16. Pseudo-Dirac neutrinos as a potential complete solution to the neutrino oscillation puzzle

    Geiser, A

    1998-01-01

    A solution for the neutrino mass and mixing pattern is proposed which is compatible with all available experimental data on neutrino oscillations. This solution involves Majorana neutrinos of the pseudo-Dirac type, i.e. $m_{\\rm Majorana} \\ll m_{\\rm Dirac}$. The solar and atmospheric neutrino observations are mainly explained as $\

  17. 15 CFR 8b.20 - Admission and recruitment.

    2010-01-01

    ... 15 Commerce and Foreign Trade 1 2010-01-01 2010-01-01 false Admission and recruitment. 8b.20... Secondary Education § 8b.20 Admission and recruitment. (a) General. Qualified handicapped may not, on the basis of handicap, be denied admission or be subjected to discrimination in admission or recruitment...

  18. Gamow-Teller beta decays of the odd-mass neighbors of the solar-neutrino detector sup 1 sup 2 sup 7 I

    Holmlund, E

    2002-01-01

    Calculations of the energy spectra and the log ft values of Gamow-Teller beta transitions of neutron-odd and proton-odd nuclei close to the solar-neutrino detector sup 1 sup 2 sup 7 I are performed using the microscopic quasiparticle-phonon model. The information obtained from the beta transition strengths is valuable in solar-neutrino detection and dark matter search both in present and future large-scale experiments. Realistic interactions within a realistic single-particle valence space were used in the calculations. The overall correspondence in terms of the excitation spectra and the log ft values between theory and experiments can be regarded as quite good when considering the completely microscopic origin of the model.

  19. A DWBA analysis of the 86Sr(anti d,p)87Sr reaction and implications for a 87Rb solar neutrino detector

    The structure of 87Sr has been investigated via the 86Sr(d vector,p)87Sr reaction using an 11.0 MeV vector-polarized deuteron beam. Differential cross sections and vector analysing powers have been measured from 200 to 1050 for 18 excited states below 4 MeV excitation energy. Comparisons of these distributions to DWBA calculations and empirical shapes were made to extract neutron spectroscopic factors and values of spin and parity for these states. Two states were identified in 87Sr below 4.0 MeV in excitation energy that would be populated by allowed solar neutrino captures in a 87Rb solar neutrino detector. (orig.)

  20. Cosmological constraints on neutrino oscillations

    Solar, atmospheric and terrestrial neutrino experiments have provided evidence for neutrino oscillations. These neutrino anomalies were successfully explained in terms of neutrino oscillations, the dominant channels being flavour neutrino oscillations. The role of sterile neutrinos and the active-sterile subdominant channels are being explored presently. Therefore, we discuss all cosmological effects of active-sterile neutrino oscillations on the early Universe evolution, and particularly the effects on the nucleosynthesis epoch. Numerical analysis of the cosmological production of He-4, Yp in the presence of νe ↔ νs, effective after νe decoupling from the equilibrium, was provided for the full neutrino oscillations parameter range. These neutrino oscillations lead always to an overproduction of He-4. We have obtained isohelium contours corresponding to different levels of He-4 overproduction, δYp/Yp, for initial population of the sterile state in the range 0 ≤ δNs ≤ 0.5. Cosmological constraints on oscillation parameters, obtained on the base of the calculated isohelium contours and Yp observational data, are discussed. We present the constraints corresponding toδNs = 0.0 and 0.5, and helium overproduction δYp/Yp = 3%. These cosmological constraints, being more stringent than the ones provided from the neutrino experimental data, provide valuable information for the impact of sterile neutrino in the neutrino anomalies and for the neutrino physics in general. (author)

  1. Neutrinos: summary of new results

    After a short presentation of the neutrino mass-mixing parameters, the core of the paper will be devoted to the recent experimental results from SNO, KamLAND and K2K. As a conclusion, I will discuss possible CP violation measurements with neutrinos. The paper is structured as follows: 1 Neutrino Oscillations Physics; 2 New results in solar neutrinos; 2.1 The SNO experiment; 2.2 The KamLAND experiment; 4 Opening the road toward a measurement of neutrino CP violation?

  2. Small Neutrino Masses: Another Anthropic principle aspect?

    Sivaram, C; O, Kiren

    2016-01-01

    This year's Physics Nobel prize for the discovery of neutrino oscillations which resolved the problem of the missing solar neutrinos and the atmospheric muon neutrinos implies that at least one of the three neutrino species has a tiny mass. The neutrino oscillations measure the mass difference squared, and the individual neutrino masses have yet to be accurately ascertained. Particle theory has so far not given a predictive picture for neutrino masses. Here we propose that the anthropic principle may be relevant, as it is frequently invoked to understand other aspects of the universe, including the precise values of fine structure constant or nuclear coupling constant or even the proton-electron mass ratio.

  3. A Compact $^{3}H(p,\\gamma)^{1}He$ 19.8-MeV Gamma-Ray Source for Energy Calibration at the Sudbury Neutrino Observatory

    Poon, A W P; Waltham, C E; Browne, M C; Roberston, R G H; Kherani, N P; Mak, H B

    2000-01-01

    The Sudbury Neutrino Observatory (SNO) is a new 1000-tonne D2O Cerenkov solar neutrino detector. A high energy gamma-ray source is needed to calibrate SNO beyond the 8B solar neutrino endpoint of 15 MeV. This paper describes the design and construction of a source that generates 19.8-MeV gamma rays using the 3H(p,gamma)4He reaction (``pt''), and demonstrates that the source meets all the physical, operational and lifetime requirements for calibrating SNO. An ion source was built into this unit to generate and to accelerate protons up to 30 keV, and a high purity scandium tritide target with a scandium-tritium atomic ratio of 1:2.0+/-0.2 was included. This pt source is the first self-contained, compact, and portable high energy gamma-ray source (E>10 MeV).

  4. Cosmic Neutrinos

    Quigg, Chris; /Fermilab /CERN

    2008-02-01

    I recall the place of neutrinos in the electroweak theory and summarize what we know about neutrino mass and flavor change. I next review the essential characteristics expected for relic neutrinos and survey what we can say about the neutrino contribution to the dark matter of the Universe. Then I discuss the standard-model interactions of ultrahigh-energy neutrinos, paying attention to the consequences of neutrino oscillations, and illustrate a few topics of interest to neutrino observatories. I conclude with short comments on the remote possibility of detecting relic neutrinos through annihilations of ultrahigh-energy neutrinos at the Z resonance.

  5. Neutrino telescopes

    Carr, J

    2002-01-01

    This review presents the scientific objectives and status of Neutrino Telescope Projects. The science program of these projects covers: neutrino astronomy, dark matter searches and measurements of neutrino oscillations. The two neutrino telescopes in operation: AMANDA and BAIKAL will be described together with the ANTARES neutrino telescope being built in the Mediterranean. (18 refs).

  6. Burst Neutrinos from Nitrogen Flash

    Serenelli, A. M.; Fukugita, M.

    2005-01-01

    Neutrinos give a novel probe to explore deep interior of astrophysical objects, which otherwise is not accessible with optical observations; among notable examples are solar and supernova neutrinos. We show that there is a new class of strong neutrino emission from helium burning, N + alpha --> 18F gamma followed by beta decay 18F --> 18O + e+ + nu_e, that gives a maximum neutrino luminosity of 10^8 times the solar bolometric luminosity at the helium-core flash of a 1 M_sun star, whereas the ...

  7. Neutrino Mass Models

    King, S F

    2004-01-01

    This is a review article about neutrino mass models, particularly see-saw models involving three active neutrinos which are capable of describing both the atmospheric neutrino oscillation data, and the large mixing angle MSW solar solution, which is now uniquely specified by recent data. We briefly review the current experimental status, show how to parametrise and construct the neutrino mixing matrix, and present the leading order neutrino Majorana mass matrices. We then introduce the see-saw mechanism, and discuss a natural application of it to current data using the sequential dominance mechanism, which we compare to an early proposal for obtaining large mixing angles. We show how both the Standard Model and the Minimal Supersymmetric Standard Model may be extended to incorporate the see-saw mechanism, and show how the latter case leads to the expectation of lepton flavour violation. The see-saw mechanism motivates models with additional symmetries such as unification and family symmetry models, and we tab...

  8. Democratic Neutrino Paradigm

    Zhuridov, Dmitry

    2014-03-01

    I will introduce a democratic neutrino theory, which sets the absolute scale of the neutrino masses at about 0.03 eV, and has only one free parameter in contrast to 7 (9) free parameters in the conventional model of Dirac (Majorana) neutrino masses and mixing. Taking into account the incoherence and matter effects, this democratic theory agrees with the atmospheric and solar neutrino data. Moreover the results of the reactor neutrino experiments with the baselines around 100 m can be better explained. I will also discuss the predictions of this theory for low energy beta decays, magnetic moments, and neutrinoless double beta decays. Supported in part by the U.S. Department of Energy under contract DE-FG02-12ER41825.

  9. Neutrino oscillations

    Lecture notes on neutrino oscillations are given, including some background about neutrino mixing and masses, descriptions of flavour oscillations and experimental attempts to detect them, matter effects and neutrino-antineutrino oscillations. (U.K.)

  10. Letter of Intent: Jinping Neutrino Experiment

    ,

    2016-01-01

    Jinping Neutrino Experiment (Jinping) is proposed to significantly improve measurements on solar neutrinos and geoneutrinos in China Jinping Laboratory - a lab with a number of unparalleled features, thickest overburden, lowest reactor neutrino background, etc., which identify it as the world-best low-energy neutrino laboratory. The proposed experiment will have target mass of 4 kilotons of liquid scintillator or water-based liquid scintillator, with a fiducial mass of 2 kilotons for neutrino-electron scattering events and 3 kilotons for inverse-beta interaction events. A number of initial sensitivities studies have been carried out, including on the transition phase for the solar neutrinos oscillation from the vacuum to the matter effect, the discovery of solar neutrinos from the carbon-nitrogen-oxygen (CNO) cycle, the resolution of the high and low metallicity hypotheses, and the unambiguous separation on U and Th cascade decays from the dominant crustal anti-electron neutrinos in China.

  11. Neutrino oscillations refitted

    Forero, D V; Valle, J W F

    2014-01-01

    Here we update our previous global fit of neutrino oscillations by including the recent results which have appeared since the Neutrino-2012 conference. These include the measurements of reactor anti-neutrino disappearance reported by Daya Bay and RENO, together with latest T2K and MINOS data including both disappearance and appearance channels. We also include the revised results from the third solar phase of Super-Kamiokande, SK-III, as well as new solar results from the fourth phase of Super-Kamiokande, SK-IV. We find that the preferred global determination of the atmospheric angle $\\theta_{23}$ is consistent with maximal mixing. We also determine the impact of the new data upon all the other neutrino oscillation parameters with emphasis on the increasing sensitivity to the CP phase, thanks to the interplay between accelerator and reactor data.

  12. Foothills Parkway Section 8B Final Environmental Report, Volume 1

    Blasing, T.J.; Cada, G.F.; Carer, M.; Chin, S.M.; Dickerman, J.A.; Etnier, D.A.; Gibson, R.; Harvey, M.; Hatcher, B.; Lietzske, D.; Mann, L.K.; Mulholland, P.J.; Petrich, C.H.; Pounds, L.; Ranney, J.; Reed, R.M.; Ryan, P.F.; Schweitzer, M.; Smith, D.; Thomason, P.; Wade, M.C.

    1999-07-01

    In 1994, Oak Ridge National Laboratory (ORNL) was tasked by the National Park Service (NPS) to prepare an Environmental Report (ER) for Section 8B of the Foothills Parkway in the Great Smoky Mountains National Park (GSMNP). Section 8B represents 27.7 km (14.2 miles) of a total of 115 km (72 miles) of the planned Foothills Parkway and would connect the Cosby community on the east to the incorporated town of Pittman Center to the west.

  13. Comparative Analysis of Brookhaven National Laboratory Nuclear Decay Data and Super-Kamiokande Neutrino Data: Indication of a Solar Connection

    Sturrock, P A

    2015-01-01

    An experiment carried out at the Brookhaven National Laboratory from February 1982 to December 1989 acquired 364 measurements of the beta-decay rates of a sample of 36Cl and of a sample of 32Si. The experimenters reported finding small periodic annual deviations of the data points from an exponential decay - of uncertain origin. We here analyze this dataset by power spectrum analysis and by forming spectrograms and phasegrams. We confirm the occurrence of annual oscillations but we also find evidence of oscillations in a band of frequencies appropriate for the internal rotation of the Sun. Both datasets show clear evidence of a transient oscillation with a frequency of 12.7 cycles per year that falls in the range of rotational frequencies for the solar radiative zone. We repeat these analyses for 358 neutrino measurements acquired by Super-Kamiokande over the interval May 1986 to August 2001. Spectrogram analysis yields a strong and steady oscillation at about 9.5 cycles per year and an intermittent oscillati...

  14. Neutrino physics

    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)

  15. Neutrino Physics

    Gil-Botella, I

    2013-01-01

    The fundamental properties of neutrinos are reviewed in these lectures. The first part is focused on the basic characteristics of neutrinos in the Standard Model and how neutrinos are detected. Neutrino masses and oscillations are introduced and a summary of the most important experimental results on neutrino oscillations to date is provided. Then, present and future experimental proposals are discussed, including new precision reactor and accelerator experiments. Finally, different approaches for measuring the neutrino mass and the nature (Majorana or Dirac) of neutrinos are reviewed. The detection of neutrinos from supernovae explosions and the information that this measurement can provide are also summarized at the end.

  16. Results from neutrino experiments

    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

  17. Neutrino Oscillation Experiments

    The current status and future propects for neutrino mass and oscillation experiments is summarized. An initial short summary of the direct neutrino mass measurements is given including double beta-decay and cosmological constraints. Next the current neutrino oscillations results are described for the solar, atmospheric, and LSND Δ m2 regions. This is followed by an overview of the expectations for the near-term reactor and long baseline experiments. Finally, the plans for the longer term oscillation program including the Hyper-K and LBNE experiments are described.

  18. Neutrino physics at Gran Sasso Laboratory

    Bettini, A

    2001-01-01

    Experiments in underground laboratories have shown strong evidence of physics beyond the standard model. The anomalies observed in electron-neutrinos from the Sun and muon-neutrinos from cosmic rays interactions in the atmosphere can be explained if neutrino oscillate and are massive. The physics program at the Gran Sasso Laboratory that we are defining will be focussed on the next phase of neutrino physics with a complementary set of experiments on the muon-neutrino beam from CERN (CNGS project), on solar neutrinos, on atmospheric neutrinos and on neutrinos from supernova explosion. The relevant thermonuclear cross-sections will be measured. The Majorana vs. Dirac nature of electron neutrinos will be explored with the search for neutrino-less double beta decays in different isotopes. (13 refs).

  19. Explosive nucleosynthesis in the neutrino-driven aspherical supernova explosion of a non-rotating 15$M_{\\odot}$ star with solar metallicity

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

    2011-01-01

    We investigate explosive nucleosynthesis in a non-rotating 15$M_\\odot$ star with solar metallicity that explodes by a neutrino-heating supernova (SN) mechanism aided by both standing accretion shock instability (SASI) and convection. To trigger explosions in our two-dimensional hydrodynamic simulations, we approximate the neutrino transport with a simple light-bulb scheme and systematically change the neutrino fluxes emitted from the protoneutron star. By a post-processing calculation, we evaluate abundances and masses of the SN ejecta for nuclei with the mass number $\\le 70$ employing a large nuclear reaction network. Aspherical abundance distributions, which are observed in nearby core-collapse SN remnants, are obtained for the non-rotating spherically-symmetric progenitor, due to the growth of low-mode SASI. Abundance pattern of the supernova ejecta is similar to that of the solar system for models whose masses ranges $(0.4-0.5) \\Ms$ of the ejecta from the inner region ($\\le 10,000\\km$) of the precollapse ...

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

    A search has been made for neutrino events (Ev > 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 νe fluxes at Ev = 50 MeV and 100 MeV. At Ev = 100 MeV, the 90% confidence-level upper limit for the time-integrated νe flux per importance 4 (3) flare is 3.5 x 107 (1.4x107) cm-2. Even the upper limit for the importance 4 flare is considerably lower than the νe flux at the corresponding energy needed to explain the excess neutrino captures reported in some of the 37Cl 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)

  1. Neutrino cosmology

    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.)

  2. Neutrino masses: from fantasy to facts

    Valle, J. W. F.

    Theory suggests the existence of neutrino masses, but little more. Facts are coming close to revealing our fantasy: solar- and atmospheric-neutrino data strongly indicate the need for neutrino conversions, while LSND provides an intriguing hint. The simplest ways to reconcile these data in terms of neutrino oscillations invoke a light sterile neutrino in addition to the three active ones. Out of the four neutrinos, two are maximally mixed and lie at the LSND scale, while the others are at the solar-mass scale. These schemes can be distinguished at neutral-current-sensitive solar- and atmospheric-neutrino experiments. I discuss the simplest theoretical scenarios, where the lightness of the sterile neutrino, the nearly maximal atmospheric-neutrino mixing and the generation of Δm {⊙/2} and Δm {atm/2} all follow naturally from the assumed lepton-number symmetry and its breaking. Although the most likely interpretation of the present data is in terms of neutrino-mass-induced oscillations, one still has room for alternative explanations, such as flavor-changing neutrino interactions, with no need for neutrino mass or mixing. Such flavor-violating transitions arise in theories with strictly massless neutrinos and may lead to other sizeable flavor non-conservation effects, such as μ → e + γ, μ - e conversion in nuclei, unaccompanied by neutrinoless double-beta decay.

  3. Neutrino propagation in matter and electromagnetic fields

    The neutrino propagation equations employed for possible solutions of the solar neutrino problem are reviewed and their derivation with the help of a Foldy-Wouthuysen transformation is discussed. The difference in the treatment of Dirac and Majorana neutrinos is particularly emphasized. (authors)

  4. Neutrino spectrum from theory and experiments

    Anjan S Joshipura

    2000-01-01

    The observed deficits in the solar and atmospheric neutrino fluxes along with the accelerator results on neutrino oscillations significantly constrain possible mass and mixing patterns among neutrinos. We discuss possible patterns emerging from the experimental results and review theoretical attempts to understand them.

  5. Neutrino masses and mixing in supersymmetric theories

    Sudhir K Vempati

    2000-07-01

    It has been known for sometime that supersymmetric theories with -parity violation provide a natural framework where small neutrino masses can be generated. We discuss neutrino masses and mixing in these theories in the presence of trilinear lepton number violating couplings. It will be shown that simultaneous solutions to solar and atmospheric neutrino problems can be realized in these models.

  6. Planck-scale physics and neutrino masses

    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

  7. Neutrino Physics

    Lederman, L. M.

    1963-01-09

    The prediction and verification of the neutrino are reviewed, together with the V A theory for its interactions (particularly the difficulties with the apparent existence of two neutrinos and the high energy cross section). The Brookhaven experiment confirming the existence of two neutrinos and the cross section increase with momentum is then described, and future neutrino experiments are considered. (D.C.W.)

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

    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

  9. Neutrino Masses

    Weinheimer, Christian

    2013-01-01

    The various experiments on neutrino oscillation evidenced that neutrinos have indeed non-zero masses but cannot tell us the absolute neutrino mass scale. This scale of neutrino masses is very important for understanding the evolution and the structure formation of the universe as well as for nuclear and particle physics beyond the present Standard Model. Complementary to deducing constraints on the sum of all neutrino masses from cosmological observations two different methods to determine the neutrino mass scale in the laboratory are pursued: the search for neutrinoless double $\\beta$-decay and the direct neutrino mass search by investigating single $\\beta$-decays or electron captures. The former method is not only sensitive to neutrino masses but also probes the Majorana character of neutrinos and thus lepton number violation with high sensitivity. Currently quite a few experiments with different techniques are being constructed, commissioned or are even running, which aim for a sensitivity on the neutrino ...

  10. The Sudbury neutrino observatory

    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

  11. Low Energy Neutrinos, Neutrino Luminosity of the Sun and LENS

    The LENS detector is designed to be a real time spectrometer sensitive to the sub-MeV part of the solar neutrino spectrum, including pp-neutrinos which dominate the solar neutrino flux. The objective of LENS is to measure the Neutrino Luminosity of the sun with high precision, which will allow a test of current standard and nonstandard neutrino flavor conversion models along with the solar model in a single experiment, and might open doors to new physics. In addition, the Gamow-energy shift in the pp-neutrino spectrum could be measured, directly probing the temperature profile of pp fusion in the solar core, thus bringing solar neutrino physics full circle to its original astrophysical objective, i.e. the study of the sun. The experimental tool used is tagged capture of νe's on 115In via charged current interaction. Tremendous progress has been achieved in the detector design, In liquid scintillator chemistry and background rejection study. A novel design for a liquid scintillator detector, the 'Scintillation Lattice Chamber' will provide 3-dimensional spatial resolution in a large mass of liquid scintillator. The feasibility of LENS with less than 200t of scintillator has been established

  12. Constraints on neutrino oscillations from big bang nucleosynthesis

    We discuss in detail the effect of neutrino oscillations in Big Bang nucleosynthesis between active and sterile neutrinos as well as between active and active neutrinos. We calculate the constraints on mixings between active and sterile neutrinos from the present observation of the primordial helium abundance and discuss the potential implications on various astrophysical and cosmological problems of such oscillations. In particular, we show that large-angle sterile neutrino mixing seems to be excluded as a MSW solution to the solar neutrino situation or a solution to the atmospheric neutrino mixing hinted at in some underground experiments. We show how, with this constraint, the next generation of solar neutrino experiments should be able to determine the resolution of the solar neutrino problem. It is also shown how sterile neutrinos remain a viable dark matter candidate

  13. Monte Carlo for the NCD phase of the Sudbury Neutrino Observatory

    In the third phase of the Sudbury Neutrino Observatory (SNO) experiment an array of 3He proportional counters was added deployed in the heavy-water volume of the SNO detector. This Neutral-Current Detection (NCD) Array detected the neutrons from the neutral-current interaction of 8B solar neutrinos with deuterium. Before we can determine the neutrino flux we must separate the neutron-capture pulses from pulses due to alpha particles and instrumental backgrounds. We have created a unique, detailed simulation of the current pulses from the proportional counters that includes energy straggling, ion drift, electron diffusion, space charge, and electronics effects. We have conducted extensive studies to determine the accuracy of the simulation. In the solar neutrino analysis the NCD Monte Carlo is used to determine the energy spectrum of the alpha background, as well as the applicable systematic effects. In the near future it will be used to fit the data pulses to separate neutron-capture and alpha pulses. With this pulse-shape analysis method the differences between pulse characteristics can be associated directly with the physical mechanisms of track formation and charge motion in the counter gas.

  14. Neutrino physics

    Harris, Deborah A.; /Fermilab

    2008-09-01

    The field of neutrino physics has expanded greatly in recent years with the discovery that neutrinos change flavor and therefore have mass. Although there are many neutrino physics results since the last DIS workshop, these proceedings concentrate on recent neutrino physics results that either add to or depend on the understanding of Deep Inelastic Scattering. They also describe the short and longer term future of neutrino DIS experiments.

  15. Low energy threshold analysis of the phase I and phase II data sets of the Sudbury neutrino observatory

    Seibert, S R [Los Alamos National Laboratory; Hime, A [Los Alamos National Laboratory; Elliott, S R [Los Alamos National Laboratory; Rielage, K [Los Alamos National Laboratory

    2009-01-01

    Results are reported from a joint analysis of Phase I and Phase II data from the Sudbury Neutrino Observatory. The effective electron kinetic energy threshold used is T{sub eff} = 3.5 MeV, the lowest analysis threshold yet achieved with water Cherenkov detector data. In units of 10{sup 6} cm{sup -2} s{sup =1}, the total flux of active-flavor neutrinos from {sup 8}B decay in the Sun measured using the neutral current (NC) reaction of neutrinos on deuterons, with no constraint on the {sup 8}B neutrino energy spectrum, is found to be {Phi}{sub NC} = 5.140{sub -0.158}{sup +0.160}(stat){sub -0.117}{sup +0.132}(syst). These uncertainties are more than a factor of two smaller than previously published results. Also presented are the spectra of recoil electrons from the charged current reaction of neutrinos on deuterons and the elastic scattering of electrons. A fit to the SNO data in which the free parameters directly describe the total {sup 8}B neutrino flux and the energy-dependent Ve survival probability provides a measure of the total {sup 8}B neutrino flux {Phi}{sub 8{sub B}} = 5.046{sub -0.152}{sup +0.159}(stat){sub -0.123}{sup +0.107}(syst). Combining these new results with results of all other solar experiments and the KamLAND reactor experiment yields best-fit values of the mixing parameters of {theta}{sub 12} = 34.06{sub -0.84}{sup +1.16} degrees and {Delta}m{sub 21}{sup 2} = 7.59{sub -0.21}{sup +0.20} x 10{sup -5} eV{sup 2}. The global value of {Phi}{sub 8{sub B}} is extracted to a precision of {sub -2.95}{sup +2.38}%. In a three-flavor analysis the best fit value of sin{sup 2} {theta}{sub 13} is 2.00{sub -1.63}{sup +2.09} x 10{sup -2}. Interpreting this as a limit implies an upper bound of sin{sup 2} {theta}{sub 13} < 0.057 (95% C. L.).

  16. Neutrino masses in astrophysics and cosmology

    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

  17. Neutrino masses in astrophysics and cosmology

    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.

  18. Atmospheric neutrinos and neutrino oscillations

    The results on the composition of atmospheric neutrinos interacting in underground detectors and on the rate of atmospheric muon neutrino interactions in the earth surrounding the detectors are reviewed. So far, systematic errors on the neutrino flux and on the electrons and muons neutrino interaction identifications are not yet reliable enough to prove that atmospheric neutrinos oscillate before being detected. (author) 22 refs., 5 figs

  19. 15 CFR 8b.21 - Treatment of students.

    2010-01-01

    ..., counseling, financial aid, physical education, athletics, recreation, transportation, other extracurricular, or other post secondary education aid, benefits, or services to which this subpart applies. (b) A... Secondary Education § 8b.21 Treatment of students. (a) General. No qualified handicapped student shall,...

  20. The sup 8 Li calibration source for the Sudbury Neutrino Observatory

    Tagg, N J; Sur, B; Earle, E D; Helmer, R L; Jonkmans, G; Moffat, B A; Simpson, J J

    2002-01-01

    A calibration source employing sup 8 Li (t sub 1 sub / sub 2 =0.838 s) has been developed for use with the Sudbury Neutrino Observatory (SNO). This source creates a spectrum of beta-particles with an energy range similar to that of the SNO sup 8 B solar neutrino signal. The source is used to test the SNO detector's energy response, position reconstruction and data reduction algorithms. The sup 8 Li isotope is created using a deuterium-tritium neutron generator in conjunction with a sup 1 sup 1 B target, and is carried to a decay chamber using a gas/aerosol transport system. The decay chamber detects prompt alpha-particles by gas scintillation in coincidence with the beta-particles which exit through a thin stainless steel wall. A description is given of the production, transport, and tagging techniques along with a discussion of the performance and application of the source.

  1. Reactor Neutrinos

    Lasserre, T; Lasserre, Thierry; Sobel, Henry W.

    2005-01-01

    We review the status and the results of reactor neutrino experiments, that toe the cutting edge of neutrino research. Short baseline experiments have provided the measurement of the reactor neutrino spectrum, and are still searching for important phenomena such as the neutrino magnetic moment. They could open the door to the measurement of coherent neutrino scattering in a near future. Middle and long baseline oscillation experiments at Chooz and KamLAND have played a relevant role in neutrino oscillation physics in the last years. It is now widely accepted that a new middle baseline disappearance reactor neutrino experiment with multiple detectors could provide a clean measurement of the last undetermined neutrino mixing angle theta13. We conclude by opening on possible use of neutrinos for Society: NonProliferation of Nuclear materials and Geophysics.

  2. Low-energy neutrino measurements

    Davide D'angelo

    2012-10-01

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

  3. Neutrino magnetic moment

    I would like to discuss the problem of a neutrino magnetic moment which is of interest since it deals with the probable time anticorrelation of the solar v flux with the Sun magnetic activity. (author). 19 refs, 2 figs, 1 tab

  4. Neutrino masses

    Buccella, F

    2004-01-01

    By requiring the lower limit for the lightest right-handed neutrino mass, obtained in the baryogenesis from leptogenesis scenario, and a Dirac neutrino mass matrix similar to the up-quark mass matrix we predict small values for the $\

  5. Oscillating neutrinos

    After a general introduction into the mixing of muon and electron neutrinos due to a possible mass difference between these particles some experiments for the study of neutrino oscillations are described. (HSI).

  6. Neutrino Astrophysics

    Haxton, W. C.

    2000-01-01

    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 an...

  7. Neutrino Physics

    Romanino, Andrea

    2012-01-01

    These lectures aim at providing a pedagogical overview of neutrino physics. We will mostly deal with standard neutrinos, the ones that are part of the Standard Model of particle physics, and with their standard dynamics, which is enough to understand in a coherent picture most of the rich data available. After introducing the basic theoretical framework, we will illustrate the experimental determination of the neutrino parameters and their theoretical implications, in particular for the origin of neutrino masses.

  8. Elastic neutrino - electron scattering and potential effects of magnetic and electric dipole moments

    W. Grimus(University of Vienna, Faculty of Physics, Boltzmanngasse 5, A-1090 Vienna, Austria); Schwetz, T.

    2000-01-01

    We consider elastic neutrino - electron scattering of solar neutrinos with magnetic moments and electric dipole moments, where the solar neutrino state at the scattering site is determined by the evolution in matter and solar magnetic fields of the initial electron neutrino state. We present the general cross section for an arbitrary superposition of active and sterile neutrino types with positive and negative helicities, with particular emphasis on the effect of transverse polarization, whic...

  9. JUNO. Determination of the neutrino mass hierarchy using reactor neutrinos

    The Jiangmen Underground Neutrino Observatory (JUNO) is a medium-baseline reactor neutrino experiment located in China. Its aim is to determine the neutrino mass hierarchy at more than 3 sigma significance after six years of data taking by using a 20kt liquid scintillator detector. To achieve this goal, an energy resolution of less than 3%/√(E) is necessary, creating strict requirements on the detector design and the liquid scintillator. Moreover, JUNO will be the only experiment in the near future able to measure the solar mixing parameters with a precision of better than 1%. This is at the same level as our current knowledge on flavour mixing in the quark sector, marking an important milestone of neutrino physics. In addition, supernova neutrinos, geo-neutrinos, sterile neutrinos as well as solar and atmospheric neutrinos can be studied. JUNO was approved in 2013 and the construction of the underground facility started early this year. In this talk the status of the experiment and its prospects is discussed.

  10. JUNO. Determination of the neutrino mass hierarchy using reactor neutrinos

    Wonsak, Bjoern [Hamburg University, Inst. Exp. Phys., Hamburg (Germany)

    2015-07-01

    The Jiangmen Underground Neutrino Observatory (JUNO) is a medium-baseline reactor neutrino experiment located in China. Its aim is to determine the neutrino mass hierarchy at more than 3 sigma significance after six years of data taking by using a 20kt liquid scintillator detector. To achieve this goal, an energy resolution of less than 3%/√(E) is necessary, creating strict requirements on the detector design and the liquid scintillator. Moreover, JUNO will be the only experiment in the near future able to measure the solar mixing parameters with a precision of better than 1%. This is at the same level as our current knowledge on flavour mixing in the quark sector, marking an important milestone of neutrino physics. In addition, supernova neutrinos, geo-neutrinos, sterile neutrinos as well as solar and atmospheric neutrinos can be studied. JUNO was approved in 2013 and the construction of the underground facility started early this year. In this talk the status of the experiment and its prospects is discussed.

  11. Neutrino Physics

    Langacker, Paul; Erler, Jens; Peinado, Eduardo

    2005-01-01

    The theoretical and experimental bases of neutrino mass and mixing are reviewed. A brief chronological evolution of the weak interactions, the electroweak Standard Model, and neutrinos is presented. Dirac and Majorana mass terms are explained as well as models such as the seesaw mechanism. Schemes for two, three and four neutrino mixings are presented.

  12. Neutrino Radar

    Panigrahi, P K

    2002-01-01

    We point out that with improving our present knowledge of experimental neutrino physics it will be possible to locate nuclear powered vehicles like submarines, aircraft carriers and UFOs and detect nuclear testing. Since neutrinos cannot be shielded, it will not be possible to escape these detection. In these detectors it will also be possible to perform neutrino oscillation experiments during any nuclear testing.

  13. Total Solar Irradiance Variability and the Solar Activity Cycle

    Raychaudhuri, Probhas

    2006-01-01

    It is suggested that the solar variability is due to the perturbed nature of the solar core and this variability is provided by the variability of the solar neutrino flux from the solar neutrino detectors i.e., Homestake, Superkamiokande, SAGE and GALLEX-GNO. The solar neutrino flux in the standard solar model (SSM) was calculated on the assumption of L_nu (neutrino luminosity) = L_gamma (optical luminosity) which implies that if there is a change in optical luminosity then solar neutrino flu...

  14. Generalized mass ordering degeneracy in neutrino oscillation experiments

    Coloma, Pilar

    2016-01-01

    We consider the impact of neutral-current (NC) non-standard neutrino interactions (NSI) on the determination of the neutrino mass ordering. We show that in presence of NSI there is an exact degeneracy which makes it impossible to determine the neutrino mass ordering and the octant of the solar mixing angle $\\theta_{12}$ at oscillation experiments. The degeneracy holds at the probability level and for arbitrary matter density profiles, and hence, solar, atmospheric, reactor, and accelerator neutrino experiments are affected simultaneously. The degeneracy requires order-one corrections from NSI to the NC electron neutrino--quark interaction and can be tested in electron neutrino NC scattering experiments.

  15. Supernova neutrinos and explosive nucleosynthesis

    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.

  16. Neutrino Factory

    Bogomilov, M; Tsenov, R; Dracos, M; Bonesini, M; Palladino, V; Tortora, L; Mori, Y; Planche, T; Lagrange, J  B; Kuno, Y; Benedetto, E; Efthymiopoulos, I; Garoby, R; Gilardoini, S; Martini, M; Wildner, E; Prior, G; Blondel, A; Karadzhow, Y; Ellis, M; Kyberd, P; Bayes, R; Laing, A; Soler, F  J  P; Alekou, A; Apollonio, M; Aslaninejad, M; Bontoiu, C; Jenner, L  J; Kurup, A; Long, K; Pasternak, J; Zarrebini, A; Poslimski, J; Blackmore, V; Cobb, J; Tunnell, C; Andreopoulos, C; Bennett, J  R  J; Brooks, S; Caretta, O; Davenne, T; Densham, C; Edgecock, T  R; Fitton, M; Kelliher, D; Loveridge, P; McFarland, A; Machida, S; Prior, C; Rees, G; Rogers, C; Rooney, M; Thomason, J; Wilcox, D; Booth, C; Skoro, G; Back, J  J; Harrison, P; Berg, J  S; Fernow, R; Gallardo, J  C; Gupta, R; Kirk, H; Simos, N; Stratakis, D; Souchlas, N; Witte, H; Bross, A; Geer, S; Johnstone, C; Mokhov, N; Neuffer, D; Popovic, M; Strait, J; Striganov, S; Morfín, J  G; Wands, R; Snopok, P; Bogacz, S  A; Morozov, V; Roblin, Y; Cline, D; Ding, X; Bromberg, C; Hart, T; Abrams, R  J; Ankenbrandt, C  M; Beard, K  B; Cummings, M  A  C; Flanagan, G; Johnson, R  P; Roberts, T  J; Yoshikawa, C  Y; Graves, V  B; McDonald, K  T; Coney, L; Hanson, G

    2014-01-01

    The properties of the neutrino provide a unique window on physics beyond that described by the standard model. The study of subleading effects in neutrino oscillations, and the race to discover CP-invariance violation in the lepton sector, has begun with the recent discovery that $\\theta_{13} > 0$. The measured value of $\\theta_{13}$ is large, emphasizing the need for a facility at which the systematic uncertainties can be reduced to the percent level. The neutrino factory, in which intense neutrino beams are produced from the decay of muons, has been shown to outperform all realistic alternatives and to be capable of making measurements of the requisite precision. Its unique discovery potential arises from the fact that only at the neutrino factory is it practical to produce high-energy electron (anti)neutrino beams of the required intensity. This paper presents the conceptual design of the neutrino factory accelerator facility developed by the European Commission Framework Programme 7 EURO$\

  17. Neutrino Lensing

    LUO Xin-Lian

    2009-01-01

    Due to the intrinsic properties of neutrinos, the gravitational lens effect for a neutrino should be more colorful and meaningful than the normal lens effect of a photon. Other than the experiments operated at terrestrial laboratory, in principle, we can propose a completely new astrophysical method to determine not only the nature of the gravity of lens objects but also the mixing parameters of neutrinos by analyzing neutrino trajectories near the central objects.However, the angular, energy and time resolution of the neutrino telescopes are still comparatively poor, so we just concentrate on the two classical tests of general relativity, i.e.the angular deflection and the time delay of the neutrino by a lens object as a preparative work in this paper.In addition, some simple properties of neutrino lensing are investigated.

  18. Future of neutrino experiments

    Takaaki Kajita

    2009-01-01

    Atmospheric, solar, reactor and accelerator neutrino oscillation experiments have measured $ m_{12}^{2}$, sin2 12, $| m_{23}^{2} |$ and sin2 223. The next stage of the oscillation studies should be the observation of a finite sin2 213. If a non-zero sin2 213 is observed, the subsequent goals should be the observation of the CP violation and the determination sign of $ m_{23}^{2}$. Possible future neutrino oscillation experiments that could assess these questions are discussed.

  19. Measurements of the atmospheric neutrino flux by Super-Kamiokande: energy spectra, geomagnetic effects, and solar modulation

    Richard, E; Abe, K; Haga, Y; Hayato, Y; Ikeda, M; Iyogi, K; Kameda, J; Kishimoto, Y; Miura, M; Moriyama, S; Nakahata, M; Nakajima, T; Nakano, Y; Nakayama, S; Orii, A; Sekiya, H; Shiozawa, M; Takeda, A; Tanaka, H; Tomura, T; Wendell, R A; Akutsu, R; Irvine, T; Kajita, T; Kaneyuki, K; Nishimura, Y; Labarga, L; Fernandez, P; Gustafson, J; Kachulis, C; Kearns, E; Raaf, J L; Stone, J L; Sulak, L R; Berkman, S; Nantais, C M; Tanaka, H A; Tobayama, S; Goldhaber, M; Kropp, W R; Mine, S; Weatherly, P; Smy, M B; Sobel, H W; Takhistov, V; Ganezer, K S; Hartfiel, B L; Hill, J; Hong, N; Kim, J Y; Lim, I T; Park, R G; Himmel, A; Li, Z; OSullivan, E; Scholberg, K; Walter, C W; Wongjirad, T; Ishizuka, T; Tasaka, S; Jang, J S; Learned, J G; Matsuno, S; Smith, S N; Friend, M; Hasegawa, T; Ishida, T; Ishii, T; Kobayashi, T; Nakadaira, T; Nakamura, K; Oyama, Y; Sakashita, K; Sekiguchi, T; Tsukamoto, T; Suzuki, A T; Takeuchi, Y; Yano, T; Cao, S V; Hiraki, T; Hirota, S; Huang, K; Kikawa, T; Minamino, A; Nakaya, T; Suzuki, K; Fukuda, Y; Choi, K; Itow, Y; Suzuki, T; Mijakowski, P; Frankiewicz, K; Hignight, J; Imber, J; Jung, C K; Li, X; Palomino, J L; Wilking, M J; Yanagisawa, C; Fukuda, D; Ishino, H; Kayano, T; Kibayashi, A; Koshio, Y; Mori, T; Sakuda, M; Xu, C; Kuno, Y; Tacik, R; Kim, S B; Okazawa, H; Choi, Y; Nishijima, K; Koshiba, M; Totsuka, Y; Suda, Y; Yokoyama, M; Bronner, C; Hartz, M; Martens, K; Marti, Ll; Suzuki, Y; Vagins, M R; Martin, J F; Konaka, A; Chen, S; Zhang, Y; Wilkes, R J

    2015-01-01

    A comprehensive study on the atmospheric neutrino flux in the energy region from sub-GeV up to several TeV using the Super-Kamiokande water Cherenkov detector is presented in this paper. The energy and azimuthal spectra of the atmospheric ${\

  20. Nuclear Interference effects in 8B sub-Coulomb breakup

    Nunes, F. M.; Thompson, I.J.

    1998-01-01

    The breakup of $^8$B on $^{58}$Ni below the Coulomb barrier was measured recently with the aim of determining the Coulomb breakup components. We reexamine this reaction, and perform one step quantum-mechanical calculations that include E1, E2 and nuclear contributions. We show that the nuclear contribution is by no means negligible at the intermediate angular range where data was taken. Our results indicate that, for an accurate description of this reaction, Coulomb E1, E2 and nuclear process...