Science.gov

Sample records for boron-8 solar neutrinos

  1. Measurement of the total boron-8 solar neutrino flux at the Sudbury Neutrino Observatory

    NASA Astrophysics Data System (ADS)

    Rusu, Vadim Liviu

    This work presents experimental measurements obtained by analyzing the first 254 live days of data from the SNO NaCl run. The electron neutrino flux was measured to be 1.66 +/- 0.10 stat.+0.07 -0.07 (syst.) x 106cm-2s-l and the non-electron neutrino flux was measured to be 3.32 +/- 0.38 stat.+0.26 -0.25 (syst.) x 106cm-2s-1. Using the above results we determined the integrated electron neutrino survival probability to be 0.33 +/- 0.04 stat.+0.02 -0.02 (syst.). This rejects maximum mixing in the solar neutrino sector at more than 3sigma using SNO data only under the assumption that the flavor changing mechanism is due to the MSW effect in the solar interior. The capability of the Sudbury Neutrino Observatory (SNO) to distinguish between the Charged-Current (CC) and Neutral-Current(NC) neutrino interactions made possible the first simultaneous measurements of the electron and non-electron solar neutrino flux, providing a direct test of the hypothesis that neutrinos change flavor as they propagate from the Sun to the Earth. Two tonnes of purified NaCl were added to the one kilotonne of heavy water target of SNO to enhance the neutron capture efficiency and detection of capture gamma-rays. Neutron capture on 35Cl often produces multiple gamma-rays, which permits a statistical separation of neutron capture and electron events based on the event isotropy, the increased statistical separation between event categories, using the degree of event isotropy, made possible a significant improvement on the measured fluxes. Moreover, the flux analysis does not require any assumption regarding the energy dependence of the flavor changing mechanism.

  2. What fraction of boron-8 solar neutrinos arrive at the earth as a nu(2) mass eigenstate?

    SciTech Connect

    Nunokawa, Hiroshi; Parke, Stephen J.; Zukanovich Funchal, Renata; /Sao Paulo U.

    2006-01-01

    We calculate the fraction of B{sup 8} solar neutrinos that arrive at the Earth as a nu{sub 2} mass eigenstate as a function of the neutrino energy. Weighting this fraction with the B{sup 8} neutrino energy spectrum and the energy dependence of the cross section for the charged current interaction on deuteron with a threshold on the kinetic energy of the recoil electrons of 5.5 MeV, we find that the integrated weighted fraction of nu{sub 2}'s to be 91 {+-} 2 % at the 95% CL. This energy weighting procedure corresponds to the charged current response of the Sudbury Neutrino Observatory (SNO). We have used SNO's current best fit values for the solar mass squared difference and the mixing angle, obtained by combining the data from all solar neutrino experiments and the reactor data from KamLAND. The uncertainty on the nu{sub 2} fraction comes primarily from the uncertainty on the solar delta m{sup 2} rather than from the uncertainty on the solar mixing angle or the Standard Solar Model. Similar results for the Super-Kamiokande experiment are also given. We extend this analysis to three neutrinos and discuss how to extract the modulus of the Maki-Nakagawa-Sakata mixing matrix element U{sub e2} as well as place a lower bound on the electron number density in the solar B{sup 8} neutrino production region.

  3. Solar Neutrinos

    DOE R&D Accomplishments Database

    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.

  4. Solar neutrinos and neutrino physics

    NASA Astrophysics Data System (ADS)

    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.

  5. Scalar currents in 0(+) going to 0(+) beta decay and the boron-8 neutrino spectrum

    NASA Astrophysics Data System (ADS)

    Ortiz, Chris Eduardo

    2000-07-01

    Two experiments to understand the standard electro-weak model are presented. In one experiment scalar contributions to the weak interaction were searched for by determining with accuracy the e - ν correlation coefficient in a 0+ --> 0+ decay. The correlation coefficient for the 0+ --> 0+ β-decay of 32Ar was measured to be a = 0.9989 +/- 0.0052 +/- 0.0036, for vanishing Fierz interference. This was used to put unprecedented limits on scalar contributions to the weak interaction. In the second experiment the β-delayed α spectrum from 8B was measured. The experiment was designed to overcome systematic uncertainties that plagued previous measurements. This spectrum differs significantly from previous measurements. The measured α spectrum was used to deduce the ν spectrum. This will be used as a benchmark by experiments trying to detect distortions of the solar-ν spectrum in the search for physics beyond the standard model.

  6. Solar Neutrino Problem

    DOE R&D Accomplishments Database

    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.

  7. Solar neutrino detection

    SciTech Connect

    Miramonti, Lino

    2009-04-30

    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.

  8. Solar neutrinos: Theoretical status

    NASA Astrophysics Data System (ADS)

    Haxton, W. C.

    I review the standard solar model, the disparities between its predictions and the solar neutrino flux measurements of the Homestake and Kamioka 2 collaborations, and possible particle physics resolutions of this puzzle. The effects of matter, including density fluctuations and turbulence, on solar neutrino oscillations are explained by building analogies with more familiar atomic physics phenomena. These and other mechanisms are considered as possible explanations for time variations in the solar neutrino flux. Finally, I consider possible outcomes and implications of the SAGE/GALLEX gallium experiments.

  9. Astroparticle physics with solar neutrinos

    PubMed Central

    NAKAHATA, Masayuki

    2011-01-01

    Solar neutrino experiments observed fluxes smaller than the expectations from the standard solar model. This discrepancy is known as the “solar neutrino problem”. Flux measurements by Super-Kamiokande and SNO have demonstrated that the solar neutrino problem is due to neutrino oscillations. Combining the results of all solar neutrino experiments, parameters for solar neutrino oscillations are obtained. Correcting for the effect of neutrino oscillations, the observed neutrino fluxes are consistent with the prediction from the standard solar model. In this article, results of solar neutrino experiments are reviewed with detailed descriptions of what Kamiokande and Super-Kamiokande have contributed to the history of astroparticle physics with solar neutrino measurements. PMID:21558758

  10. Recent Results in Solar Neutrinos

    NASA Astrophysics Data System (ADS)

    Saldanha, Richard

    2011-10-01

    Solar neutrinos are an invaluable tool for studying neutrino oscillations in matter as well as probing the nuclear reactions that fuel the Sun. In this talk I will give an overview of solar neutrinos and discuss the latest results in the field. I will highlight the recent precision measurement of the ^7Be solar neutrino interaction rate with the Borexino solar neutrino detector and present the status of the analysis of pep and CNO neutrinos. I will also briefly describe future experiments and their potential to detect low energy solar neutrinos.

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

    NASA Astrophysics Data System (ADS)

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

    2016-05-01

    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 sin2 θ W 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 quantify 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. Our analysis shows that 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 8B flux determination. Assuming a low-mass argon phase, projected tonne-scale experiments like DARWIN can reduce the uncertainty on both the pp and boron-8 neutrino fluxes to below 1%. Finally, we use current results from LUX, SuperCDMS and CDMSlite to set bounds on new interactions between neutrinos and electrons or nuclei, and show that future direct detection experiments can be used to set complementary constraints on the parameter space associated with light mediators.

  12. Solar Neutrinos. II. Experimental

    DOE R&D Accomplishments Database

    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.)

  13. Experimental data on solar neutrinos

    NASA Astrophysics Data System (ADS)

    Ludhova, Livia

    2016-04-01

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

  14. An Experimentalist's Overview of Solar Neutrinos

    NASA Astrophysics Data System (ADS)

    Oser, Scott M.

    2012-02-01

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

  15. Solar neutrinos: Probing the sun or neutrinos

    SciTech Connect

    Wilkerson, J.F.

    1991-01-01

    The decade of the 1990's should prove to be a 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 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.

  16. Oscillations of solar atmosphere neutrinos

    SciTech Connect

    Fogli, G. L.; Lisi, E.; Mirizzi, A.; Montanino, D.; Serpico, P. D.

    2006-11-01

    The Sun is a source of high-energy neutrinos (E(greater-or-similar sign)10 GeV) produced by cosmic ray interactions in the solar atmosphere. We study the impact of three-flavor oscillations (in vacuum and in matter) on solar atmosphere neutrinos, and calculate their observable fluxes at Earth, as well as their event rates in a kilometer-scale detector in water or ice. We find that peculiar three-flavor oscillation effects in matter, which can occur in the energy range probed by solar atmosphere neutrinos, are significantly suppressed by averaging over the production region and over the neutrino and antineutrino components. In particular, we find that the relation between the neutrino fluxes at the Sun and at the Earth can be approximately expressed in terms of phase-averaged vacuum oscillations, dominated by a single mixing parameter (the angle {theta}{sub 23})

  17. Solar Neutrinos: Status and Prospects

    NASA Astrophysics Data System (ADS)

    Haxton, W. C.; Hamish Robertson, R. G.; Serenelli, Aldo M.

    2013-08-01

    We describe the current status of solar neutrino measurements and of the theory—both neutrino physics and solar astrophysics—employed in interpreting measurements. Important recent developments include Super-Kamiokande's determination of the ν-e elastic scattering rate for 8B neutrinos to 3%; the latest Sudbury Neutrino Observatory (SNO) global analysis in which the inclusion of low-energy data from SNO I and II significantly narrowed the range of allowed values for the neutrino mixing angle θ12; Borexino results for both the 7Be and proton-electron-proton (pep) neutrino fluxes, the first direct measurements constraining the rate of proton-proton (pp) I and pp II burning in the Sun; global reanalyses of solar neutrino data that take into account new reactor results on θ13; a new decadal evaluation of the nuclear physics of the pp chain and CNO cycle defining best values and uncertainties in the nuclear microphysics input to solar models; recognition of an emerging discrepancy between two tests of solar metallicity, helioseismological mappings of the sound speed in the solar interior, and analyses of the metal photoabsorption lines based on our best current description of the Sun's photosphere; a new round of standard solar model calculations optimized to agree either with helioseismology or with the new photospheric analysis; and, motivated by the solar abundance problem, the development of nonstandard, accreting solar models, in order to investigate possible consequences of the metal segregation that occurred in the proto-solar disk. We review this progress and describe how new experiments such as SNO+ could help us further exploit neutrinos as a unique probe of stellar interiors.

  18. Solar Neutrinos, SNO and SNOLAB

    NASA Astrophysics Data System (ADS)

    McDonald, A. B.

    2007-06-01

    The Sudbury Neutrino Observatory has completed operation in its third phase with an array of neutron detectors in 1000 tonnes of heavy water and Cherenkov light detection 2 km underground in INCO's Creighton mine near Sudbury, Ontario, Canada. Data from the third phase is now being analyzed. In the first two phases of the project reported previously, the neutral current reaction on deuterium was used to determine the total flux of active neutrinos and the charged current reaction on deuterium provided a measure of the flux and energy spectrum of solar electron neutrinos. The flux of electron neutrinos was found to be only about one third of the total flux, providing clear evidence of neutrino flavour change. The total flux of active neutrinos was found to be in agreement with solar model calculations. The underground laboratory is being expanded to create an international facility known as SNOLAB that will be completed at the end of 2007. Proposed future experiments for the detection of lower energy solar neutrinos, geo-neutrinos, dark matter and double beta decay are described.

  19. Report on solar neutrino experiments

    SciTech Connect

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

    1984-01-01

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

  20. Solar photons, phonons and neutrinos

    NASA Astrophysics Data System (ADS)

    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.

  1. Variations in the Solar Neutrino Flux

    DOE R&D Accomplishments Database

    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.

  2. Precision Solar Neutrino Measurements with the Sudbury Neutrino Observatory

    SciTech Connect

    Oblath, Noah

    2007-10-26

    The Sudbury Neutrino Observatory (SNO) is the first experiment to measure the total flux of active, high-energy neutrinos from the sun. Results from SNO have solved the long-standing 'Solar Neutrino Problem' by demonstrating that neutrinos change flavor. SNO measured the total neutrino flux with the neutral-current interaction of solar neutrinos with 1000 tonnes of D{sub 2}O. In the first two phases of the experiment we detected the neutron from that interaction by capture on deuterium and capture on chlorine, respectively. In the third phase an array of {sup 3}He proportional counters was deployed in the detector. This allows a measurement of the neutral-current neutrons that is independent of the Cherenkov light detected by the PMT array. We are currently developing a unique, detailed simulation of the current pulses from the proportional-counter array that will be used to help distinguish signal and background pulses.

  3. Particle physics confronts the solar neutrino problem

    SciTech Connect

    Pal, P.B.

    1991-06-01

    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.

  4. Solar and Terrestrial Neutrino Results from Borexino

    NASA Astrophysics Data System (ADS)

    Calaprice, Frank; Borexino Collaboration

    2012-08-01

    Borexino is a low background liquid scintillation detector currently acquiring solar and terrestrial neutrino data at the LNGS underground laboratory in Italy. In the three years since the start of operations in 2007, Borexino has produced measurements of 7Be and 8B solar neutrinos, as well as measurements of terrestrial and long-baseline reactor anti-neutrinos. The measurements of sub-MeV neutrinos were possible owing to a breakthrough in low background methods. Current results and prospects for future measurements with lower background and higher accuracy are discussed in the context of exploring the transition from vacuum to matter enhanced neutrino oscillations.

  5. John Bahcall and the Solar Neutrino Problem

    NASA Astrophysics Data System (ADS)

    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.

  6. Solar neutrinos, helioseismology and the solar internal dynamics

    NASA Astrophysics Data System (ADS)

    Turck-Chièze, Sylvaine; Couvidat, Sébastien

    2011-08-01

    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

  7. Electron-neutrino survival probability from solar-neutrino data

    NASA Astrophysics Data System (ADS)

    Berezinsky, V.; Lissia, M.

    2001-11-01

    With SNO data [SNO Collaboration, nucl-ex/0106015] on electron-neutrino flux from the sun, it is possible to derive the νe survival probability Pee(E) from existing experimental data of Super-Kamiokande, gallium experiments and Homestake. The combined data of SNO and Super-Kamiokande provide boron νe flux and the total flux of all active boron neutrinos, giving thus Pee(E) for boron neutrinos. The Homestake detector, after subtraction of the signal from boron neutrinos, gives the flux of Be/+CNO neutrinos, and Pee for the corresponding energy interval, if the produced flux is taken from the Standard Solar Model (SSM). Gallium detectors, GALLEX, SAGE and GNO, detect additionally /pp-neutrinos. The /pp flux can be calculated subtracting from the gallium signal the rate due to boron, beryllium and CNO neutrinos. The ratio of the measured /pp-neutrino flux to that predicted by the SSM gives the survival probability for /pp-neutrinos. Comparison with theoretical survival probabilities shows that the best (among known models) fit is given by LMA and LOW solutions.

  8. Variations in the solar neutrino flux

    SciTech Connect

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

    1987-01-01

    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.

  9. Constraining Neutrino Magnetic Moments with Solar and Reactor Neutrino Data

    NASA Astrophysics Data System (ADS)

    Tórtola, M. A.

    We use the latest solar neutrino data, combined with the results of the reactor experiment KamLAND, to derive stringent bounds on Majorana neutrino transition moments (TMs). Furthermore, we show how the inclusion of data from the reactor experiments Rovno, MUNU and TEXONO in our analysis improves significantly the current constraints on TMs. Finally, we perform a simulation of the future Borexino experiment and show that it will improve the bounds from today's data by one order of magnitude.

  10. Calibration of the solar neutrino detectors

    NASA Astrophysics Data System (ADS)

    Caccianiga, Barbara; Re, Alessandra Carlotta

    2016-04-01

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

  11. Results from the Borexino Solar Neutrino Experiment

    NASA Astrophysics Data System (ADS)

    Calaprice, Frank; Galbiati, Cristiano; Wright, Alex; Ianni, Aldo

    2012-11-01

    Borexino is a low-background liquid scintillation detector currently acquiring solar and terrestrial neutrino data at the Gran Sasso underground laboratory in Italy. Since the start of operations in 2007, Borexino has produced measurements of 7Be, 8B, and pep solar neutrinos, as well as measurements of terrestrial and long-baseline reactor antineutrinos. The measurements were made possible by the development of low-background scintillator spectroscopy that enabled direct detection of sub-MeV solar neutrinos. The general design features of the detector are described together with current results and prospects for future measurements.

  12. The status of the solar neutrino problem

    SciTech Connect

    Bowles, T.J.

    1993-12-01

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

  13. SAGE: Solar Neutrino Data from SAGE, the Russian-American Gallium Solar Neutrino Experiment

    DOE Data Explorer

    SAGE Collaboration

    SAGE is a solar neutrino experiment based on the reaction 71Ga + n goes to 71Ge + e-. The 71Ge atoms are chemically extracted from a 50-metric ton target of Ga metal and concentrated in a sample of germane gas mixed with xenon. The atoms are then individually counted by observing their decay back to 71Ga in a small proportional counter. The distinguishing feature of the experiment is its ability to detect the low-energy neutrinos from proton-proton fusion. These neutrinos, which are made in the primary reaction that provides the Sun's energy, are the major component of the solar neutrino flux and have not been observed in any other way. To shield the experiment from cosmic rays, it is located deep underground in a specially built facility at the Baksan Neutrino Observatory in the northern Caucasus mountains of Russia. Nearly 100 measurements of the solar neutrino flux have been made during 1990-2000, and their combined result is a neutrino capture rate that is well below the prediction of the Standard Solar Model. The significant suppression of the solar neutrino flux that SAGE and other solar neutrino experiments have observed gives a strong indication for the existence of neutrino oscillations. [copied from the SAGE homepage at http://ewi.npl.washington.edu/SAGE/SAGE.html

  14. Solar oscillation frequency and solar neutrino predictions

    SciTech Connect

    Cox, A.N.

    1990-07-05

    The light and velocity variations of the Sun and solar-like stars are unique among intrinsic variable stars. Unlike all other standard classes, such as Cepheids, B stars, and white dwarfs, the pulsation driving is caused by coupling with the acoustic noise in the upper convection zone. Each global pulsation mode is just another degree of freedom for the turbulent convection, and energy is shared equally between these g{sup {minus}}-modes and the solar oscillation modes. This driving and damping, together with the normal stellar pulsation mechanisms produce extremely low amplitude solar oscillations. Actually, the surface layer radiative damping is strong, and the varying oscillation mode amplitudes manifest the stochastic convection driving and the steady damping. Thus stability calculations for solar-like pulsations are difficult and mostly inconclusive, but calculations of pulsation periods are as straightforward as for all the other classes of intrinsic variable stars. The issue that is important for the Sun is its internal structure, because the mass, radius, and luminosity are extremely well known. Conventionally, we need the pulsation constants for each of millions of modes. Unknown parameters for constructing solar models are the composition and its material pressure, energy, and opacity, as well as the convection mixing length. We treat the nuclear energy and neutrino production formulas as sufficiently well known. The presence of weakly interacting massive particles (WIMPs) orbiting the solar center affects the predicted oscillation frequencies so that they do not agree with observations as well as those for models without WIMPs. 34 refs., 4 figs.

  15. First measurement of the flux of solar neutrinos from the sun at the Sudbury Neutrino Observatory

    NASA Astrophysics Data System (ADS)

    Wittich, Peter

    2000-12-01

    The Sudbury Neutrino Observatory (SNO) is a second generation solar neutrino detector. SNO is the first experiment that is able to measure both the electron neutrino flux and a flavor-blind flux of all active neutrino types, allowing a model-independent determination if the deficit of solar neutrinos known as the solar neutrino problem is due to neutrino oscillation. The Sudbury Neutrino Observatory started taking production data in November, 1999. A measurement of the charged current rate will be the first indication if SNO too sees a suppression of the solar neutrino signal relative to the theoretical predictions. Such a confirmation is the first step in SNO's ambitious science program. In this thesis, we present evidence that SNO is seeing solar neutrinos and a preliminary ratio of the measured vs predicted rate of electrons as induced by 8B neutrinos in the νe, + d --> p + p + e charged-current (CC) reaction.

  16. Solar core homology, solar neutrinos and helioseismology

    SciTech Connect

    Bludman, S.A.; Kennedy, D.C.

    1995-12-31

    Precise numerical standard solar models (SSMs) now agree with one another and with helioseismological observations in the convective and outer radiative zones. Nevertheless these models obscure how luminosity, neutrino production and g-mode core helioseismology depend on such inputs as opacity and nuclear cross sections. Although the Sun is not homologous, its inner core by itself is chemically evolved and almost homologous, because of its compactness, radiative energy transport, and ppI-dominated luminosity production. We apply luminosity-fixed homology transformations to the core to estimate theoretical uncertainties in the SSM and to obtain a broad class of non-SSMs, parameterized by central temperature and density and purely radiative energy transport in the core. 25 refs., 3 figs., 3 tabs.

  17. Solar neutrino experiments: recent results and future prospects

    NASA Astrophysics Data System (ADS)

    Chen, M. C.

    2011-09-01

    Recent results from the SNO and Borexino solar neutrino experiments have pushed the observation of solar neutrinos to lower energies. Borexino's measurement of the rate of 7Be solar neutrinos demonstrates that the survival probability for solar neutrinos below 1 MeV is larger than for the 8B solar neutrinos, consistent with our expectation for neutrino propagation affected by matter. On the other hand, by looking at lower energy 8B solar neutrinos, SNO (and also Borexino) do not see the predicted rise in the survival probability and there is even a hint that the survival probability drops to a lower value. Future solar neutrino experiments, in particular the SNO+ experiment, will look at this question by making precision measurements of the survival probability of the pep solar neutrinos (1.44 MeV energy).

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

    NASA Technical Reports Server (NTRS)

    Raychaudhuri, P.

    1985-01-01

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

  19. Everything under the sun: A review of solar neutrinos

    DOE PAGESBeta

    Gann, Gabriel D. Orebi

    2015-07-15

    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.

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

    SciTech Connect

    Gann, Gabriel D. Orebi

    2015-07-15

    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.

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

    NASA Astrophysics Data System (ADS)

    Gann, Gabriel D. Orebi

    2015-07-01

    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.

  2. Linking solar and long baseline terrestrial neutrino experiments.

    PubMed

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

    2000-04-17

    We show that, in the framework of three light neutrino species with hierarchical masses and assuming no fine tuning between the entries of the neutrino mass matrix, one can use the solar neutrino data to obtain information on the element U(e3) of the lepton mixing matrix. Conversely, a measurement of U(e3) in atmospheric or long baseline accelerator or reactor neutrino experiments would help discriminate between possible oscillation solutions of the solar neutrino problem. PMID:11019139

  3. Solar neutrinos, Martian rivers, and Praesepe.

    NASA Technical Reports Server (NTRS)

    Sagan, C.; Young, A. T.

    1973-01-01

    Some recent papers on solar neutrinos, Martian rivers, and Praesepe stars are reviewed. Possible causes of solar neutrino detection rates being below theoretical expectations are quoted. The widespread presence of sinuous dendritic channels on Mars is noted. The occurrence of earth-like epochs on Mars is indicated as a plausible explanation for many such channels in terms of surface liquid water flows. The roughly uniform distribution of the Praesepe stars through the main sequence width is viewed as the indication that the excursion time off the main sequence is comparable to the time between mixings.

  4. Radiochemical Solar Neutrino Experiments - Successful and Otherwise.

    SciTech Connect

    Hahn,R.L.

    2008-05-25

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

  5. Solar neutrinos: Real-time experiments

    NASA Astrophysics Data System (ADS)

    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.

  6. Effect of radiative corrections on the solar neutrino spectrum

    SciTech Connect

    Batkin, I.S.; Sundaresan, M.K.

    1995-11-01

    In this paper we calculate the changes to the solar neutrino spectrum arising from the radiative corrections in the {beta} decay processes responsible for the production of the neutrinos. Explicit results are given for the neutrinos arising from the {ital pp} reaction and for the {sup 8}B neutrinos.

  7. Solar neutrino physics in the nineties

    SciTech Connect

    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.

  8. Report of the Solar and Atmospheric Neutrino Working Group

    SciTech Connect

    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

  9. Solar neutrinos results and oscillation analysis from Super-Kamiokande

    NASA Astrophysics Data System (ADS)

    Koshio, Yusuke

    The results of the solar neutrino spectrum measurement in Super-Kamiokande is presented. The precise measurement of the solar neutrino enegy spectrum is one of the most important key issue to understand neutrino oscillations. In order to measure the spectrum, it is very important to precisely determin the energy scale of the detector. For this purpose, we have used an electron LINAC. This calibration can be done at several positions, directions and energy points, and it can reduce the systematic errors of energy scale less than 1. Neutrino oscillations are essentially energy dependent phenomena. Actually different solar neutrino oscillation solutions require the different energy dependece. In addition, such a measurement is independent the absolute flux results of solar models. Therefore an observation of the deviation from the expected energy spectrum not only show the definite evidence of the solar neutrino oscillation, but also differenciate the possible oscillation solutions. The results of the extensive analysis on neutrino oscillation is presented.

  10. Solar Neutrino flare detection in Hyperkamiokande and SK

    NASA Astrophysics Data System (ADS)

    Fargion, Daniele

    2016-07-01

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

  11. Correlation between solar neutrino flux and other solar phenomena

    NASA Technical Reports Server (NTRS)

    Lal, S.; Subramanian, A.

    1985-01-01

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

  12. Report on the Brookhaven Solar Neutrino Experiment

    DOE R&D Accomplishments Database

    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.

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

    NASA Astrophysics Data System (ADS)

    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.

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

    NASA Astrophysics Data System (ADS)

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

    1992-08-01

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

  15. 17 keV neutrino and large magnetic moment solution of the solar neutrino puzzle

    NASA Astrophysics Data System (ADS)

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

    1993-01-01

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

  16. The analysis of solar models: Neutrinos and oscillations

    NASA Technical Reports Server (NTRS)

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

    1983-01-01

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

  17. Towards the resolution of the solar neutrino problem

    SciTech Connect

    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} {theta} {le} {pi}/4 in the presence of

  18. CNO and pep solar neutrino measurements and perspectives in Borexino

    NASA Astrophysics Data System (ADS)

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

    2016-02-01

    The detection of neutrinos emitted in the CNO reactions in the Sun is one of the ambitious goals of Borexino Phase-II. A measurement of CNO neutrinos would be a milestone in astrophysics, and would allow to solve serious issues in current solar models. A precise measurement of the rate of neutrinos from the pep reaction would allow to investigate neutrino oscillations in the MSW transition region. The pep and CNO solar neutrino physics, the measurement in Borexino Phase-I and the perspectives for the new phase are reviewed in this proceeding.

  19. Solar neutrino experiments and a test for neutrino oscillations with radioactive sources

    SciTech Connect

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

    1980-01-01

    The results of the Brookhaven solar neutrino experiment are given and compared to the most recent standard solar model calculations. The observations are about a factor of 4 below theoretical expectations. In view of the uncertainties involved in the theoretical models of the sun, the discrepancy is not considered to be evidence for neutrino oscillations. The status of the development of a gallium solar neutrino detector is described. Radiochemical neutrino detectors can be used to search for ..nu../sub e/ oscillations by using megacurie sources of monoenergetic neutrinos like /sup 65/Zn. A quantitative evaluation of possible experiments using the Brookhaven chlorine solar neutrino detector and a gallium detector is given. 6 figures, 3 tables.

  20. Possible explanation of the solar-neutrino puzzle

    NASA Technical Reports Server (NTRS)

    Bethe, H. A.

    1986-01-01

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

  1. Large-scale liquid scintillation detectors for solar neutrinos

    NASA Astrophysics Data System (ADS)

    Benziger, Jay B.; Calaprice, Frank P.

    2016-04-01

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

  2. Limits on C P T violation from solar neutrinos

    NASA Astrophysics Data System (ADS)

    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 .

  3. Detecting Solar Neutrino Flare in Megaton and km3 detectors

    NASA Astrophysics Data System (ADS)

    Fargion, Daniele; di Giacomo, Paola

    2009-03-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2016-07-01

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

  5. Neutrino oscillations and uncertainty in the solar model

    NASA Astrophysics Data System (ADS)

    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.

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

    NASA Astrophysics Data System (ADS)

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

    2015-05-01

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

  7. Testing the principle of equivalence by solar neutrinos

    SciTech Connect

    Minakata, Hisakazu |; Nunokawa, Hiroshi |

    1994-04-01

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

  8. E sub 6 leptoquarks and the solar neutrino problem

    NASA Technical Reports Server (NTRS)

    Roulet, Esteban

    1991-01-01

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

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

    NASA Astrophysics Data System (ADS)

    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.

  10. 7Be Solar Neutrino Measurement with KamLAND

    SciTech Connect

    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.

  11. 7Be solar neutrino measurement with KamLAND

    NASA Astrophysics Data System (ADS)

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

    2015-11-01

    We report a measurement of the neutrino-electron elastic scattering rate of 862 keV 7Be solar neutrinos based on a 165.4 kt d exposure of KamLAND. The observed rate is 582 ±94 (kt d)-1, which corresponds to an 862-keV 7Be solar neutrino flux of (3.26 ±0.52 ) ×109cm-2s-1 , assuming a pure electron-flavor flux. Comparing this flux with the standard solar model prediction and further assuming three-flavor mixing, a νe survival probability of 0.66 ±0.15 is determined from the KamLAND data. Utilizing a global three-flavor oscillation analysis, we obtain a total 7Be solar neutrino flux of (5.82 ±1.02 ) ×109cm-2s-1 , which is consistent with the standard solar model predictions.

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

    SciTech Connect

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

    1986-04-01

    Mikheyev and Smirnov have shown that the interactions of neutrinos with matter can result in the conversion of electron neutrinos produced in the center of the sun to muon neutrinos. Bethe has exploited this and has pointed out that the solar-neutrino puzzle can be resolved if the mass difference squared of the two neutrinos is m/sub 2//sup 2/ - m /sub 1//sup 2/ approx. = 6 x 10/sup -5/ eV/sup 2/, and the mixing angle satisfies sin theta/sub v/ > 0.0065. We discuss a qualitatively different solution to the solar-neutrino puzzle which requires 1.0 x 10/sup -8/ < (m/sub 2//sup 2/ - m/sub 1//sup 2/) (sin/sup 2/ 2theta/sub v//cos 2theta/sub v/) < 6.1 x 10/sup -8/ eV/sup 2/. Our solutions result in a much smaller flux of neutrinos from the p - p process than predicted by standard solar models, while Bethe's solution results in a flux of neutrinos from the p - process that is about the same as standard solar models.

  13. Neutrino conversions in solar random magnetic fields

    NASA Astrophysics Data System (ADS)

    Semikoz, V. B.; Torrente-Lujan, E.

    1999-09-01

    We consider the effect of a random magnetic field in the convective zone of the Sun superimposed to a regular magnetic field on resonant neutrino spin-flavor oscillations. We argue for the existence of a field of strongly chaotic nature at the bottom of the convective zone. In contrast to previous attempts we employ a model motivated regular magnetic field profile: it is a static field solution to the solar equilibrium hydro-magnetic equations. These solutions have been known for a long time in the literature. We show for the first time that in addition they are twisting solutions. In this scenario electron antineutrinos are produced through cascades like νeL-->νμL-- >ν~eR, The detection of ν~eR at Earth would be a long-awaited signature of the Majorana nature of the neutrino. The expected signals in the different experiments (SK, GALLEX-SAGE, Homestake) are obtained as a function of the level of noise, regular magnetic field and neutrino mixing parameters. Previous results obtained for small mixing and ad-hoc regular magnetic profiles are reobtained. We confirm the strong suppression for a large part of the parameter space of the ν~eR-flux for high energy boron neutrinos in agreement with present data of the SK experiment. We find that MSW (Mikheyev-Smirnov-Wolfenstein) regions (Δm2~=10-5 eV2, both small and large mixing solutions) are stable up to very large levels of noise (P=0.7-0.8) but they are acceptable from the point of view of antineutrino production only for moderate levels of noise (P~=0.95). For strong noise and a reasonable regular magnetic field, any parameter region (Δm2, sin 2 2θ) is excluded. As a consequence, we are allowed to reverse the problem and to put limits on the r.m.s. field strength and transition magnetic moments by demanding a particle physics solution to the SNP in this scenario.

  14. The Sudbury Neutrino Observatory: Observation of Flavor Change for Solar Neutrinos

    NASA Astrophysics Data System (ADS)

    McDonald, A. B.

    2016-03-01

    The Sudbury Neutrino Observatory (SNO) detector was developed by an international scientific collaboration (Canada, US, UK) to use 1000 tonnes of heavy water 2 km underground in ultra-clean conditions to observe flavor change for solar neutrinos from 8B decay in the sun. A clear observation of neutrino change was obtained by comparing two neutrino reactions on deuterium, one sensitive only to electron flavor neutrinos and one sensitive equally to all active neutrino types. The design and construction and the operation and data analysis for the three separate phases of the experiment will be described. The initial phase with pure heavy water provided conclusive evidence for flavor change and hence finite mass for neutrinos. Subsequent phases within added NaCl and with an array of neutron detectors provided improved accuracy for the measurements of oscillation parameters. The observed total flux of 8B solar electron neutrinos is in excellent agreement with and more accurate than solar models. Modification of the SNO detector to create SNO + and expansion of the laboratory to create a long-term international underground laboratory, SNOLAB, will be briefly described.

  15. Data analysis in solar neutrinos liquid-scintillator detectors

    NASA Astrophysics Data System (ADS)

    Testera, G.

    2016-04-01

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

  16. The Need for new neutrino physics or a cooler sun in the solar neutrino problem

    SciTech Connect

    Shi, X.; Schramm, D. N.

    1992-11-22

    t is shown that the current solar neutrino situation, now that we have the SAGE and GALLEX result along with the results from the Kamioksnde and the Homestake experiments, is unfortunately still quite ambiguous. The differences between observations and the standard solar theory may still be due to either astrophysical inputs or new neutrino physics. In particular, the astrophysical solution, which requires a cooler Sun than the standard solar model of Bahcsll et al., may still be viable. The need for new neutrino physics, MSW or vacuum neutrino mixing, is sensitive to the results of the Homestake experiment and SAGE. The use of future experiments, SNO, Borexino, the Super Kamiokande, and the Iodine experiment to resolve this ambiguity are explicitly discussed.

  17. Status of the Borexino Solar Neutrino Experiment, 2006

    SciTech Connect

    McCarty, Kevin B.

    2006-11-17

    The Borexino experiment is designed to measure the flux of 7Be solar neutrinos. The experiment, having a 100-ton fiducial volume of organic liquid scintillator, should detect roughly 35 neutrinos per day in the energy range 250 - 1300 keV, a range lower than that of any previous real-time neutrino detector. Though the 862-keV 7Be neutrinos make up roughly 10% of the total solar neutrino flux, they have not previously been directly observed. Their energy is at a delicate point for confirmation of the vacuum-to-matter oscillation transition. In these proceedings, I will present the status of the Borexino experiment as of August 2006, as we prepare for final filling of the detector.

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

    NASA Astrophysics Data System (ADS)

    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

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

    NASA Astrophysics Data System (ADS)

    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

  20. Light sterile neutrinos, spin flavor precession, and the solar neutrino experiments

    NASA Astrophysics Data System (ADS)

    Das, C. R.; Pulido, João; Picariello, Marco

    2009-04-01

    We generalize to three active flavors a previous two-flavor model for the resonant spin flavor conversion of solar neutrinos to sterile ones, a mechanism which is added to the well-known large mixing angle (LMA) one. The transition magnetic moments from the muon and tau neutrinos to the sterile play the dominant role in fixing the amount of active flavor suppression. We also show, through numerical integration of the evolution equations, that the data from all solar neutrino experiments except Borexino exhibit a clear preference for a sizable magnetic field either in the convection zone or in the core and radiation zone. This is possibly related to the fact that the data from the first set are average ones taken during a period of mostly intense solar activity, whereas in contrast Borexino data were taken during a period of quiet Sun. We argue that the solar neutrino experiments are capable of tracing the possible modulation of the solar magnetic field. Those monitoring the high-energy neutrinos, namely, the B8 flux, appear to be sensitive to a field modulation either in the convection zone or in the core and radiation zone. Those monitoring the low-energy fluxes will be sensitive to the second type of solar field profiles only. In this way Borexino alone may play an essential role, since it examines both energy sectors, although experimental redundancy from other experiments will be most important.

  1. Update of GALLEX solar neutrino results and implications

    SciTech Connect

    Kirsten, T.

    1995-01-01

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

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

    SciTech Connect

    Lopes, Ilidio; Silk, Joseph E-mail: ilopes@uevora.pt

    2012-06-20

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

  3. Solar Models Based on Helioseismology and the Solar Neutrino Problem

    NASA Astrophysics Data System (ADS)

    Takata, Masao; Shibahashi, Hiromoto

    1998-09-01

    We have determined the sound-speed profile in the Sun by carrying out an asymptotic inversion of the helioseismic data from the Low-Degree (l) Oscillation Experiment (LOWL), the Global Oscillation Network Group (GONG), VIRGO on SOHO, the High-l Helioseismometer (HLH), and observations made at the South Pole. We then deduce the density, pressure, temperature, and elemental composition profiles in the solar radiative interior by solving the basic equations governing the stellar structure, with the imposition of the determined sound-speed profile and with a constraint on the depth of the convection zone obtained from helioseismic analysis and the ratio of the metal abundance to the hydrogen abundance at the photosphere. With the exception of the treatment of elements relevant to nuclear reactions, we assume that Z is homogeneous. The chemical composition profiles of hydrogen and helium are then obtained as a part of the solutions. Using the resulting seismic model, we estimate the neutrino fluxes and the neutrino capture rates for the chlorine, gallium, and water Čerenkov experiments. Even if we take into account uncertainties in various input physics, the estimated capture rates are still significantly larger than the observation.

  4. A broken E6 solution to the solar neutrino problem

    NASA Astrophysics Data System (ADS)

    Ross, G. G.; Segrè, G. C.

    1987-10-01

    Broken E6 models, as suggested by superstrings, may have stable massive neutrinos in matter multiplets. These can be candidates for the dark matter of the universe. If we choose an additional Z' in the E6 gauge multiplet to couple to these neutrinos, but not ordinary leptons, we may also solve the solar neutrino problem, without violating known experimental bounds. The Z' must have a mass comparable to the ordinary Z mass. On sabbatical leave from Department of Physics, University of Pennsylvania, Philadelphia, PA 19104, USA.

  5. Evidence for electron neutrino flavor change through measurement of the (8)B solar neutrino flux at the Sudbury Neutrino Observatory

    NASA Astrophysics Data System (ADS)

    Neubauer, Mark Stephen

    2001-11-01

    The Sudbury Neutrino Observatory (SNO) is a water Cerenkov detector designed to study solar neutrinos. Using 1 kiloton of heavy water as the target and detection medium, SNO is able to separately determine the flux of electron neutrinos (νe) and the flux of all active neutrinos from the Sun by measuring the rate of charged current (CC) and neutral current (NC) interactions with deuterons. A comparison of these interaction rates allows for direct observation of solar neutrino oscillations. SNO can also search for oscillations by comparing the rate of CC and neutrino- electron elastic scattering (ES) events, since ES has both charged current and neutral current sensitivity. In this thesis, we present measurement of the 8B solar ν e flux of 1.78+0.13-0.14 (stat+syst) × 106cm-2s -1 (35% BP2000 SSM) through measurement of the CC rate over 169.3 days of livetime. We have also measured the 8B flux from the ES reaction to be 2.56+0.48-0.45 (stat+syst), consistent with measurements by previous water Cerenkov experiments. A flavor analysis comparing the CC measured flux with that determined through ES by SuperKamiokande yields a non- νe active neutrino flux from 8B of 3.62+1.06-1.08 × 106cm-2s-1 , providing evidence for νe --> ν μ,τ oscillations as a solution to the solar neutrino problem. This result excludes pure solar νe --> ν s oscillations at greater than the 99.7% C.I. The total active 8B neutrino flux has been measured to be 5.39+1.07-1.09 × 106cm-2s-1 , consistent with BP2000 SSM predictions. First analyses of the CC (NHit) spectrum and hep flux in SNO are presented. The CC spectrum is found to be a good fit to expectations from an undistorted 8B spectrum, and global best fit vacuum oscillation solutions are disfavored over the other solutions by the data. Through observations near the 8B endpoint with consideration of energy systematics, hep flux limits of 4.1 (90% C.I.) and 6.9 (99% C.I.) times SSM expectations are obtained. A statistical fit for the

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

    PubMed

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

    2014-03-01

    We report an indication that the elastic scattering rate of solar B8 neutrinos with electrons in the Super-Kamiokande detector is larger when the neutrinos pass through Earth during nighttime. We determine the day-night asymmetry, defined as the difference of the average day rate and average night rate divided by the average of those two rates, to be [-3.2 ± 1.1(stat) ± 0.5(syst)]%, which deviates from zero by 2.7 σ. Since the elastic scattering process is mostly sensitive to electron-flavored solar neutrinos, a nonzero day-night asymmetry implies that the flavor oscillations of solar neutrinos are affected by the presence of matter within the neutrinos' flight path. Super-Kamiokande's day-night asymmetry is consistent with neutrino oscillations for 4 × 10(-5)  eV(2) ≤ Δm 2(21) ≤ 7 × 10(-5) eV(2) and large mixing values of θ12, at the 68% C.L. PMID:24655245

  7. Solar neutrinos and 1-3 leptonic mixing

    SciTech Connect

    Goswami, Srubabati; Smirnov, Alexei Yu.

    2005-09-01

    Effects of the 1-3 leptonic mixing on the solar neutrino observables are studied and the signatures of nonzero {theta}{sub 13} are identified. For this we have rederived the formula for 3{nu}-survival probability including all relevant corrections and constructed the isocontours of observables in the sin{sup 2}{theta}{sub 12}-sin{sup 2}{theta}{sub 13} plane. Analysis of the solar neutrino data gives sin{sup 2}{theta}{sub 13}=0.007{sub -0.007}{sup +0.080} (90% C.L.) for {delta}m{sup 2}=8x10{sup -5} eV{sup 2}. The combination of the ratio CC/NC at Sudbury Neutrino Observatory (SNO) and gallium production rate selects sin{sup 2}{theta}{sub 13}=0.017{+-}0.026 (1{sigma}). The global fit of all oscillation data leads to zero best value of sin{sup 2}{theta}{sub 13}. The sensitivity (1{sigma} error) of future solar neutrino studies to sin{sup 2}{theta}{sub 13} can be improved down to 0.01-0.02 by precise measurements of the pp-neutrino flux and the CC/NC ratio as well as spectrum distortion at high (E>4 MeV) energies. Combination of experimental results sensitive to the low and high energy parts of the solar neutrino spectrum resolves the degeneracy of angles {theta}{sub 13} and {theta}{sub 12}. Comparison of sin{sup 2}{theta}{sub 13} as well as sin{sup 2}{theta}{sub 12} measured in the solar neutrinos and in the reactor/accelerator experiments may reveal new effects which can not be seen otherwise.

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

    NASA Astrophysics Data System (ADS)

    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.

  9. Analytical description of quasivacuum oscillations of solar neutrinos

    NASA Astrophysics Data System (ADS)

    Lisi, E.; Marrone, A.; Montanino, D.; Palazzo, A.; Petcov, S. T.

    2001-05-01

    We propose a simple prescription to calculate the solar neutrino survival probability Pee in the quasivacuum oscillation (QVO) regime. Such a prescription is obtained by matching perturbative and exact analytical results, which effectively take into account the density distribution in the Sun as provided by the standard solar model. The resulting analytical recipe for the calculation of Pee is shown to reach its highest accuracy (\\|ΔPee\\|<=2.6×10-2 in the whole QVO range) when the familiar prescription of choosing the solar density scale parameter r0 at the Mikheyev-Smirnov-Wolfenstein (MSW) resonance point is replaced by a new one, namely, when r0 is chosen at the point of ``maximal violation of adiabaticity'' (MVA) along the neutrino trajectory in the Sun. The MVA prescription admits a smooth transition from the QVO regime to the MSW transition one. We discuss in detail the phase acquired by neutrinos in the Sun, and show that it might be of relevance for the studies of relatively short time scale variations of the fluxes of the solar ν lines in the future real-time solar neutrino experiments. Finally, we elucidate the role of matter effects in the convective zone of the Sun.

  10. Achievements in solar neutrino physics with the Borexino detector

    NASA Astrophysics Data System (ADS)

    Miramonti, L.; Borexino Collaboration

    2015-11-01

    Borexino is an organic liquid scintillator detector located in the Gran Sasso National Laboratory in central Italy. It has been designed for real-time spectroscopy of low energy solar neutrinos. In Phase I of the experiment lasting for three years, between May 2007 and May 2010, the Collaboration performed the first independent measurements of 7Be, 8B, and pep solar neutrino fluxes. After a dedicated purification campaign of the liquid scintillator in 2011, Borexino entered into Phase II which allowed to investigate the seasonal modulation in the 7Be signal. In 2014, Borexino provided the first direct real time measurement of pp neutrinos accomplishing the whole pp-cycle that powers the Sun.

  11. The solar neutrino deficit -- Principle and interest (a modern problem)

    SciTech Connect

    Robertson, R.G.H.

    1995-12-31

    Sufficient data now exist that tests, independent of any solar model, can be made of whether solar neutrino experiment are consistent with the minimal Standard Model (stable, massless neutrinos). If the experimental uncertainties are correctly estimated and the sun is generating energy by light-element fusion in quasi-static equilibrium, the probability of a standard-physics solution is less than 1.2%. Even when the luminosity constraint is abandoned, the probability is not more than 5%. The sensitivity of the conclusions to input parameters is explored. New experiments nearing completion (SNO and SuperKamiokande) are expected to provide decisive evidence of neutrino oscillations, if they are indeed the explanation.

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

    NASA Astrophysics Data System (ADS)

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

    2016-07-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2008-03-01

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

  14. Solar neutrinos and the influence of radiative opacities on solar models

    NASA Technical Reports Server (NTRS)

    Carson, T. R.; Ezer, D.; Stothers, R.

    1973-01-01

    Use of new radiative opacities based on the hot Thomas-Fermi model of the atom yields a predicted solar neutrino flux which is still considerably larger than the flux observed in Davis's Cl-37 experiment.

  15. The Effect of Very Low Energy Solar Neutrinos on the MSW Mechanism

    NASA Astrophysics Data System (ADS)

    Esposito, S.

    We study some implications on standard matter oscillations of solar neutrinos induced by a background of extremely low energy thermal neutrinos trapped inside the Sun by means of coherent refractive interactions. Possible experimental tests are envisaged and current data on solar neutrinos detected at Earth are briefly discussed.

  16. Neutrino flavor ratios as diagnostic of solar WIMP annihilation

    NASA Astrophysics Data System (ADS)

    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

  17. Variations of the core luminosity and solar neutrino fluxes

    NASA Astrophysics Data System (ADS)

    Grandpierre, Attila

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

  18. Review of solar neutrinos and the MSW effect

    SciTech Connect

    Rosen, S.P.

    1990-01-01

    I review the MSW solution to the solar neutrino problem in light of the existing data from the {sup 37}Cl and Kamiokande II experiments. Taken together, they disfavor the adiabatic solution and tend to support either the large angle solution or the nonadiabatic one. In both cases the {sup 71}Ga experiment will yield a much smaller signal than that predicted by the standard solar model; the suppression factor in the former case will be about the same as for {sup 37}Cl, and in the latter it could be as large as 10 or more. I await the outcome of this experiment with great anticipation. 10 refs.

  19. First Evidence of pep Solar Neutrinos by Direct Detection in Borexino

    NASA Astrophysics Data System (ADS)

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

    2012-02-01

    We observed, for the first time, solar neutrinos in the 1.0-1.5 MeV energy range. We determined the rate of pep solar neutrino interactions in Borexino to be 3.1±0.6stat±0.3systcounts/(day·100ton). Assuming the pep neutrino flux predicted by the standard solar model, we obtained a constraint on the CNO solar neutrino interaction rate of <7.9counts/(day·100ton) (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. The necessary sensitivity was achieved by adopting data analysis techniques for the rejection of cosmogenic C11, the dominant background in the 1-2 MeV region. Assuming the Mikheyev-Smirnov-Wolfenstein large mixing angle solution to solar neutrino oscillations, these values correspond to solar neutrino fluxes of (1.6±0.3)×108cm-2s-1 and <7.7×108cm-2s-1 (95% C.L.), respectively, in agreement with both the high and low metallicity standard solar models. These results represent the first direct evidence of the pep neutrino signal and the strongest constraint of the CNO solar neutrino flux to date.

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

    NASA Astrophysics Data System (ADS)

    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 <7.9 counts/(day-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. The necessary sensitivity was achieved by adopting 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)×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.

  1. Contribution of gallium experiments to the understanding of solar physics and neutrino physics

    SciTech Connect

    Gavrin, V. N.

    2013-10-15

    The results of gallium measurements of solar neutrino and measurements with artificial sources of neutrinos are presented. Conclusions are drawn from these results, and the potential of the SAGE experiment for studying transitions of active neutrinos to sterile states for {Delta}m{sup 2} > 0.5 eV{sup 2} and a sensitivity of a few percent to the disappearance of electron neutrinos is examined.

  2. A step toward CNO solar neutrino detection in liquid scintillators

    NASA Astrophysics Data System (ADS)

    Villante, F. L.; Ianni, A.; Lombardi, F.; Pagliaroli, G.; Vissani, F.

    2011-07-01

    The detection of CNO solar neutrinos in ultrapure liquid scintillator detectors is limited by the background produced by bismuth-210 nuclei that undergo β-decay to polonium-210 with a lifetime of ˜7 days. Polonium-210 nuclei are unstable and decay with a lifetime equal to ˜200 days emitting α particles that can be also detected. In this Letter, we show that the Bi-210 background can be determined by looking at the time evolution of α-decay rate of Po-210, provided that α particle detection efficiency is stable over the data acquisition period and external sources of Po-210 are negligible. A sufficient accuracy can be obtained in a relatively short time. As an example, if the initial Po-210 event rate is ˜2000 cpd/100 ton or lower, a Borexino-like detector could start discerning CNO neutrino signal from Bi-210 background in Δt˜1 yr.

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

    NASA Astrophysics Data System (ADS)

    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 (< 1 MeV) and high (> 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.

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

    NASA Astrophysics Data System (ADS)

    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 <8.3 day-1(100 ton)-1 (95% C.L.). The absence of the solar neutrino signal is disfavored at 99.99997% C.L., while the absence of the pep neutrino signal is disfavored at 98% C.L. The necessary sensitivity was achieved due to the extremely low levels of radioactive contamination in Borexino and by adopting data analysis 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.

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

    NASA Astrophysics Data System (ADS)

    Ejiri, Hiroyasu; Zuber, Kai

    2016-08-01

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

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

    NASA Astrophysics Data System (ADS)

    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.

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

    NASA Astrophysics Data System (ADS)

    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).

  8. Implications of the Recent Results of Solar Neutrino Experiments

    NASA Astrophysics Data System (ADS)

    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.

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

    NASA Astrophysics Data System (ADS)

    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.

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

    SciTech Connect

    Bowles, T.J.

    1994-04-01

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

  11. Measurement of Solar pp-neutrino flux with Borexino: results and implications

    NASA Astrophysics Data System (ADS)

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

    2016-02-01

    Measurement of the Solar pp-neutrino flux completed the measurement of Solar neutrino fluxes from the pp-chain of reactions in Borexino experiment. The result is in agreement with the prediction of the Standard Solar Model and the MSW/LMA oscillation scenario. A comparison of the total neutrino flux from the Sun with Solar luminosity in photons provides a test of the stability of the Sun on the 105 years time scale, and sets a strong limit on the power production by the unknown energy sources in the Sun.

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

    NASA Astrophysics Data System (ADS)

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

    2004-05-01

    The Sudbury Neutrino Observatory has precisely determined the total active (νx) 8B solar neutrino flux without assumptions about the energy dependence of the νe survival probability. The measurements were made with dissolved NaCl in heavy water to enhance the sensitivity and signature for neutral-current interactions. The flux is found to be 5.21±0.27(stat)±0.38(syst)×106 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 Δm2=7.1+1.2-0.6×10-5 eV2 and θ=32.5+2.4-2.3 degrees. Maximal mixing is rejected at the equivalent of 5.4 standard deviations.

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

    NASA Astrophysics Data System (ADS)

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

    2016-07-01

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

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

    SciTech Connect

    Lopes, Ilidio; Turck-Chieze, Sylvaine E-mail: ilopes@uevora.pt

    2013-03-01

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

  15. Neutrino Experiments

    SciTech Connect

    McKeown, R. D.

    2010-08-04

    Recent studies of neutrino oscillations have established the existence of finite neutrino masses and mixing between generations of neutrinos. The combined results from studies of atmospheric neutrinos, solar neutrinos, reactor antineutrinos and neutrinos produced at accelerators paint an intriguing picture that clearly requires modification of the standard model of particle physics. These results also provide clear motivation for future neutrino oscillation experiments as well as searches for direct neutrino mass and nuclear double-beta decay. I will discuss the program of new neutrino oscillation experiments aimed at completing our knowledge of the neutrino mixing matrix.

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

    SciTech Connect

    Lukyanchenko, G. A.; Collaboration: Borexino Collaboration

    2015-12-15

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

  17. Neutrinos

    PubMed Central

    Besson, Dave; Cowen, Doug; Selen, Mats; Wiebusch, Christopher

    1999-01-01

    Neutrinos represent a new “window” to the Universe, spanning a large range of energy. We discuss the science of neutrino astrophysics and focus on two energy regimes. At “lower” energies (≈1 MeV), studies of neutrinos born inside the sun, or produced in interactions of cosmic rays with the atmosphere, have allowed the first incontrovertible evidence that neutrinos have mass. At energies typically one thousand to one million times higher, sources further than the sun (both within the Milky Way and beyond) are expected to produce a flux of particles that can be detected only through neutrinos. PMID:10588680

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

    NASA Astrophysics Data System (ADS)

    Lopes, Ilídio; Silk, Joseph

    2013-11-01

    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) neutrino fluxes are the most affected; this is due to the fact that contrarily to proton-proton (pp, pep, 8B and 7Be) neutrino fluxes, the CNO neutrino fluxes are less dependent on the total luminosity of the star. Furthermore, if the central solar metallicity increases by 30 per cent, as hinted by the solar twin stars observations, this new solar model predicts that 13N, 15O and 17F neutrino fluxes increase by 25-80 per cent relative to the standard solar model. Finally, we highlight that the next generation of solar neutrino experiments will not only put constraints on the abundances of carbon, oxygen and nitrogen, but will also give some information about their radial distribution.

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

    NASA Astrophysics Data System (ADS)

    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.

  20. Probing the Sun's inner core using solar neutrinos: A new diagnostic method

    NASA Astrophysics Data System (ADS)

    Lopes, Ilídio

    2013-08-01

    The electronic density in the Sun’s inner core is inferred from the B8, Be7 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.

  1. Solar neutrinos: Near-far asymmetry and just-so oscillations

    SciTech Connect

    Faied, B.; Fogli, G.L.; Montanino, D.

    1997-02-01

    We propose to study possible signals of just-so oscillations in new-generation solar neutrino experiments by separating the events detected when the Earth is nearest to the Sun (perihelion {plus_minus} 3 months) from those detected when the Earth is farthest from the Sun (aphelion {plus_minus} 3 months). We introduce a solar-model-independent near-far asymmetry, which is nonzero if just-so oscillations occur. We apply our calculations to the kinetic energy spectra of electrons induced by {sup 8}B solar neutrino interactions in the SuperKamiokande and Sudbury Neutrino Observatory experiments. We show that the sensitivity to the neutrino oscillation parameters can be increased by probing the near-far asymmetry in selected parts of the electron energy spectra. {copyright} {ital 1997} {ital The American Physical Society}

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

    NASA Astrophysics Data System (ADS)

    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.

  3. High precision 7Be solar neutrinos measurement and day night effect obtained with Borexino

    NASA Astrophysics Data System (ADS)

    Testera, G.; Bellini, G.; Benziger, J.; Bick, D.; Bonetti, S.; Bonfini, G.; Caccianiga, B.; Cadonati, L.; Calaprice, F.; Carraro, C.; Chavarria, A.; D'Angelo, D.; Derbin, A.; Etenko, A.; Fomenko, K.; Franco, D.; Galbiati, C.; Gazzana, S.; Ghiano, C.; Giammarchi, M.; Göger-Neff, M.; Goretti, A.; Grandi, L.; Guardincerri, E.; Hardy, S.; Ianni, Aldo; Ianni, Andrea; Korablev, D.; Kobychev, V.; Korga, G.; Koshio, Y.; Kryn, D.; Laubenstein, M.; Leung, M.; Lewke, T.; Litvinovich, E.; Loer, B.; Lombardi, P.; Lombardi, F.; Ludhova, L.; Machulin, I.; Manecki, S.; Maneschg, W.; Manuzio, G.; Meindl, Q.; Meroni, E.; Miramonti, L.; Misiaszek, M.; Montanari, D.; Mosteiro, P.; Muratova, V.; Oberauer, L.; Obolensky, M.; Ortica, F.; Pallavicini, M.; Papp, L.; Pena-Garay, C.; Perasso, L.; Perasso, S.; Pocar, A.; Raghavan, R. S.; Ranucci, G.; Razeto, 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.; Vignaud, D.; Vogelaar, R. B.; von Feilitzsch, F.; Winter, J.; Wojcik, M.; Wurm, M.; Zaimidoroga, O.; Zavatarelli, S.; Zuzel, G.

    2012-11-01

    We report the direct measurement of the 7Be solar neutrino signal rate performed with the Borexino detector at the Laboratori Nazionali del Gran Sasso and the search for a day-night asymmetry of this interaction rate. The interaction rate of the 0.862 MeV 7Be neutrinos is 46±1.6(stat)-1.6+1.5(syst) counts/(day · 100 ton). The hypothesis of no oscillation for this solar neutrinos is inconsistent with our measurement at the 5.8σ C.L. Our result is the first direct measurement of solar neutrinos with an accuracy better than 5%. We report the survival probability for solar νe in the transition region between matter-enhanced and vacuum-driven oscillations. The measured day night asymmetry is Adn=0.001±0.012 (stat)±0.007 (syst), in agreement with the predicition of MSW-LMA neutrino [13] oscillations. This result discourages MSW oscillations with mixing parameters in the LOW region at more than 8.5σ, meaning that this region is, for the first time, strongly rejected without the assumption of CPT symmetry. The result can also be used to constrain some neutrino oscillation scenarios involving new physics.

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

    SciTech Connect

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

    2011-06-04

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

  5. Feasibility of /sup 81/Br(nu,e/sup -/)/sup 81/Kr solar neutrino experiment

    SciTech Connect

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

    1985-05-01

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

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

    SciTech Connect

    Lopes, Ilídio; Turck-Chièze, Sylvaine E-mail: ilopes@uevora.pt

    2014-09-10

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

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

    NASA Technical Reports Server (NTRS)

    Sakurai, K.; Hasegawa, M.

    1985-01-01

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

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

    SciTech Connect

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

    2013-09-15

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

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

    NASA Technical Reports Server (NTRS)

    Shi, X.; Schramm, David N.

    1991-01-01

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

  10. Precision measurement of solar neutrino oscillation parameters by a long-baseline reactor neutrino experiment in Europe

    NASA Astrophysics Data System (ADS)

    Petcov, S. T.; Schwetz, T.

    2006-11-01

    We consider the determination of the solar neutrino oscillation parameters Δm212 and θ12 by studying oscillations of reactor anti-neutrinos emitted by nuclear power plants (located mainly in France) with a detector installed in the Frejus underground laboratory. The performances of a water Čerenkov detector of 147 kt fiducial mass doped with 0.1% of gadolinium (MEMPHYS-Gd) and of a 50 kt scale liquid scintillator detector (LENA) are compared. In both cases 3σ uncertainties below 3% on Δm212 and of about 20% on sin2θ12 can be obtained after one year of data taking. The gadolinium doped Super-Kamiokande detector (SK-Gd) in Japan can reach a similar precision if the SK/MEMPHYS fiducial mass ratio of 1 to 7 is compensated by a longer SK-Gd data taking time. Several years of reactor neutrino data collected by MEMPHYS-Gd or LENA would allow a determination of Δm212 and sin2θ12 with uncertainties of approximately 1% and 10% at 3σ, respectively. These accuracies are comparable to those that can be reached in the measurement of the atmospheric neutrino oscillation parameters Δm312 and sin2θ23 in long-baseline superbeam experiments.

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

    SciTech Connect

    Elliott, Steven Ray

    2008-01-01

    The Russian-American experiment SAGE began to measure the solar neutrino capture rate with a target of gallium metal in December 1989. Measurements have continued with only a few brief interruptions since that time. In this article we present the experimental improvements in SAGE since its last published data summary in December 2001. Assuming the solar neutrino production rate was constant during the period of data collection, combined analysis of 168 extractions through December 2007 gives a capture rate of solar neutrinos with energy more than 233 keY of 65.4{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.

  12. Hans Bethe Prize Recipient: Solar Neutrinos: from Darwin to Bethe to Superkamiokande and SNO

    NASA Astrophysics Data System (ADS)

    Bahcall, John

    1998-04-01

    The nineteenth century debate on the origin of stellar energy generation was resolved theoretically by Hans Bethe in the late 1930's and experimentally by Ray Davis in the 1970's. Kamiokande showed conclusively in the 1990s that the observed neutrinos come from the sun. Five beautiful experiments (chlorine, Kamiokande, GALLEX, SAGE, and Superkamiokande) have by now detected solar neutrinos, which have approximately the fluxes and energies predicted by calculations of nuclear fusion rates in standard solar models. Quantitative discrepancies between the standard model predictions (which assume that nothing happens to the neutrinos after they are created) and the measurements provide evidence that physics beyond the standard electroweak model may be manifested in solar neutrino experiments. Recent helioseismological measurements strengthen this inference. I will summarize the current status of solar neutrino research and review the prospects for discovering ``smoking-gun'' evidence for new physics with the Superkamiokande, SNO, and BOREXINO detectors.

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

    NASA Astrophysics Data System (ADS)

    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.

  14. THE SOLAR ENERGETIC BALANCE REVISITED BY YOUNG SOLAR ANALOGS, HELIOSEISMOLOGY, AND NEUTRINOS

    SciTech Connect

    Turck-Chieze, Sylvaine; Piau, Laurent

    2011-04-20

    The energetic balance of the standard solar model (SSM) results from equilibrium between nuclear energy production, energy transfer, and photospheric emission. In this Letter, we give an order of magnitude of several percent for the loss of energy in kinetic energy, magnetic energy, and X-ray or UV radiation during the entire solar lifetime from the observations of the present Sun. We also estimate the loss of mass from the observations of young solar analogs, which could reach up to 30%. We deduce new models of the present Sun, their associated neutrino fluxes, and internal sound-speed profile. This approach sheds quantitative lights on the disagreement between the sound speed obtained by helioseismology and the sound speed derived from the SSM including the updated photospheric CNO abundances, based on recent observations. We conclude that about 20% of the present discrepancy could come from the incorrect description of the early phases of the Sun, its activity, its initial mass, and mass-loss history. This study has obvious consequences on the solar system formation and the early evolution of the closest planets.

  15. Solar-cycle modulation of event rates in the chlorine solar neutrino experiment

    NASA Astrophysics Data System (ADS)

    Bahcall, John N.; Press, William H.

    1991-04-01

    The time dependence of the event rates in the Homestake chlorine solar neutrino experiment are reexamined using new Ar-37 production data covering the period from late 1986 to mid-1989. The data span almost two complete solar cycles. A careful statistical analysis using nonparametric rank-order statistics is used to calculate quantitative significance levels that do not depend on experimental errors. The results show that the Ar-37 production rate in the experiment is anticorrelated with solar activity for approximately 1977-1989. The shape of the Ar-37 production rate is different from the inverted sunspot activity curve. The Ar-37 production rate is better descrbed by a skewed sawtooth function than by the sunspot number. The best-fitting sawtooth function with sunspot period has a slow rise and a rapid decline. The Ar-37 maximum occurs about 12.5 yr after the solar sunspot minimum, while minimum Ar-37 production is more nearly simultaneous with the sunspot maximum.

  16. Absence of a day-night asymmetry in the 7Be solar neutrino rate in Borexino

    NASA Astrophysics Data System (ADS)

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

    2012-01-01

    We report the result of a search for a day-night asymmetry in the 7Be solar neutrino interaction rate in the Borexino detector at the Laboratori Nazionali del Gran Sasso (LNGS) in Italy. The measured asymmetry is Adn = 0.001 ± 0.012 (stat) ± 0.007 (syst), in agreement with the prediction of MSW-LMA solution for neutrino oscillations. This result disfavors MSW oscillations with mixing parameters in the LOW region at more than 8.5 σ. This region is, for the first time, strongly disfavored without the use of reactor anti-neutrino data and therefore the assumption of CPT symmetry. The result can also be used to constrain some neutrino oscillation scenarios involving new physics.

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

    NASA Astrophysics Data System (ADS)

    Bellini, G.; Benziger, J.; Bick, D.; Bonfini, G.; Bravo, D.; Buizza Avanzini, M.; 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.; Gabriele, F.; Galbiati, C.; Gazzana, S.; Ghiano, C.; Giammarchi, M.; Göger-Neff, M.; Goretti, A.; Grandi, L.; Gromov, M.; 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.; Montuschi, 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.; 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

    2014-06-01

    Borexino has been running since May 2007 at the Laboratori Nazionali del Gran Sasso laboratory in Italy 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 Phase-I (2007-2010), Borexino first detected and then precisely measured the flux of the Be7 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 solar neutrinos produced in the CNO cycle (carbon, nitrogen, oxigen) where carbon, nitrogen, and oxygen serve as catalysts in the fusion process. 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 innermost fiducial volume with extremely low background via software cuts, and the excellent pulse-shape discrimination capability of the scintillator that allows particle identification. We report a measurement of the annual modulation of the Be7 neutrino interaction rate. The period, the amplitude, and the phase of the observed modulation are consistent with the solar origin of these events, and the absence of their annual modulation is rejected with higher than 99% C.L. The physics implications of Phase-I results in the context of the neutrino oscillation physics and solar models are presented.

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

    SciTech Connect

    Moskalenko, Igor V.; Porter, Troy A.; 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.

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

    NASA Technical Reports Server (NTRS)

    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.

  20. Neutrinos

    NASA Astrophysics Data System (ADS)

    Winter, K.; Murdin, P.

    2000-11-01

    Neutrinos are electrically neutral ELEMENTARY PARTICLES which experience only the weak nuclear force and gravity. Their existence was introduced as a hypothesis by Wolfgang Pauli in 1930 to explain the apparent violation of energy conservation in radioactive beta decay. Chadwick had discovered in 1914 that the energy spectrum of electrons emitted in beta decay was not monoenergetic but continuous...

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

    NASA Astrophysics Data System (ADS)

    Antonelli, V.; Miramonti, L.

    2014-06-01

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

  2. Measurement of the response of a Ga solar neutrino experiment to neutrinos from a {sup 37}Ar source

    SciTech Connect

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

    2006-04-15

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

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

    NASA Technical Reports Server (NTRS)

    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.

  4. Non-adiabatic resonant conversion of solar neutrinos in three generations

    NASA Astrophysics Data System (ADS)

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

    1987-02-01

    The survival probability of solar electron neutrinos after non-adiabatic passage through the resonance-oscillation region in the Sun is discussed for the case of three generations. A method to calculate three-generation Landau-Zener transition probabilities between adiabatic states is described. We also discuss how the Landua-Zener probability is modified in the extreme non-adiabatic case.

  5. Proton decay and solar neutrino experiment with a liquid argon Time Projection Chamber

    SciTech Connect

    Chen, H.H.; Doe, P.J.; Mahler, H.I.

    1983-01-01

    Recent progress in development of the liquid argon Time Projection Chamber is reviewed. Application of this technique to a search for proton decay and /sup 8/B solar neutrinos with directional sensitivity is considered. The steps necessary for a large scale application of this technique deep underground are described.

  6. A search for the detection of high energy solar neutrinos in the IceCube Detector

    NASA Astrophysics Data System (ADS)

    Guo, Cheng

    The IceCube Neutrino Telescope at the South Pole, completed in December of 2010, consists of 5160 Digital Optical Modules (DOMs) mounted on 80 vertical 1-km long strings arranged in a hexagonal pattern. Each string contains 60 DOMs located at a depth of 1450-2450 meters under the ice. The closely spaced inner arrays in the deepest ice, called DeepCore, enables the IceCube Neutrino Observatory to detect neutrinos at energies as low as 10 GeV. A special SN trigger based on a ≥ 6σ excess on top of the dark count-rate background in the DOMs is used to indicate a possible SN explosion. A close study of solar activities due to the onset of the solar cycle 24, revealed correlations between the IceCube Supernova trigger events and increased solar activities. In this thesis, we discuss these correlations and present the results and overall contribution of possible backgrounds due to the seasonal variation of the atmospheric muons. We conclude that these triggers are the results of high energy neutrino production in the sun. We expect the rate to increase with the maximum of the solar activities in mid 2013 and subsequently drop afterwards.

  7. {sup 7}Be(p, {gamma}){sup 8}B and the high-energy solar neutrino flux

    SciTech Connect

    Csoto, A.

    1997-08-01

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

  8. Solar neutrino limit on axions and keV-mass bosons

    SciTech Connect

    Gondolo, Paolo; Raffelt, Georg G.

    2009-05-15

    The all-flavor solar neutrino flux measured by the Sudbury Neutrino Observatory constrains nonstandard energy losses to less than about 10% of the Sun's photon luminosity, superseding a helioseismological argument and providing new limits on the interaction strength of low-mass particles. For the axion-photon coupling strength we find g{sub a{gamma}}<7x10{sup -10} GeV{sup -1}. We also derive explicit limits on the Yukawa coupling to electrons of pseudoscalar, scalar, and vector bosons with keV-scale masses.

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

    NASA Astrophysics Data System (ADS)

    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.

  10. Neutrino

    NASA Astrophysics Data System (ADS)

    Han, Yongquan

    2015-04-01

    The most basic Quantum are the particles who mutual rotation, quantum is composed of basic quantum.Quantum convergence or divergence is conditional, the faster the particle rotates, the smaller the orbiting radius will be, the greater quality is, the more density will be. The orbiting radius of less than 10-15 meters in the order of convergence, convergence of neutron, proton, and then they are in the formation of the nucleus, and the convergence of quantum can make extra nuclear electron and the formation of atomic; if rotation radius is more than 10-15 meters of magnitude, the internal quantum atoms diverge to outer space in the form of electromagnetic waves. The quality of magnetic wave particle is composed of the rotation speed of the particle which is internal of the electromagnetic, it doesn't matter about the electromagnetic wave propagation velocity of particles. Neutrinos are orbiting particles, the orbiting radius is about 10-15 meters, is a special kind of radiation. Neutrino is between the virtual particles (according to modern science, the electromagnetic wave doesn't have quality) and modern scientific (the particle who has quality) special particles

  11. Chasing the ghost particle: The long and winding road toward the detection of solar neutrinos

    NASA Astrophysics Data System (ADS)

    Leone, Matteo; Robotti, Nadia

    2015-10-01

    One of the great achievements of neutrino physics was the discovery of solar neutrinos in 1968 through the Homestake underground experiment. This experiment exploited a radiochemical method based on the chlorine-argon process of inverse beta decay suggested by Bruno Pontecorvo in 1946 during his work in the classified Canadian nuclear project. In this paper, we study the emergence of the method. We focus on the role played by the problematic status of the neutrino and its antiparticle in its field of application and the influence exerted by the contemporary models of energy production in the sun. We also provide evidence that a first germ of this radiochemical method, in the form of a chlorine-sulfur process, was suggested in a paper published by Richard Crane in late 1930s.

  12. Neutrino magnetic moment

    SciTech Connect

    Chang, D. . Dept. of Physics and Astronomy Fermi National Accelerator Lab., Batavia, IL ); Senjanovic, G. . Dept. of Theoretical Physics)

    1990-01-01

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

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

    NASA Astrophysics Data System (ADS)

    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.

  14. Production and suppression of {sup 11}C in the solar neutrino experiment Borexino

    SciTech Connect

    Meindl, Quirin; Bellini, G.; Benziger, J.; Bonetti, S.; Avanzini, M. Buizza; Caccianiga, B.; Cadonati, L.; Calaprice, F.; Carraro, C.; Chavarria, A.; Chepurnov, A.; Dalnoki-Veress, F.; D'Angelo, D.; Davini, S.; Kerret, H. de; Derbin, A.; Etenko, A.; Feilitzsch, F. von; Fomenko, K.; Franco, D.

    2011-04-27

    Cosmogenic {sup 11}C is produced in-situ by atmospheric muons and forms the main background for the measurement of solar pep- and CNO-neutrinos. However, FLUKA simulations show that the majority of {sup 11}C is accompanied by a free neutron in the final state, thus allowing for an efficient tagging method, the so-called Three-Fold Coincidence technique. The technique and its first applications on Borexino data are presented.

  15. ( sup 6 Li, sup 6 He) measurements as an alternative calibration for solar neutrino detectors

    SciTech Connect

    Aschenauer, E.; Dennert, H.; Eyrich, W.; Lehmann, A.; Moosburger, M.; Wirth, H. ); Gils, H.J.; Rebel, H.; Zagromski, S. )

    1991-12-01

    The ({sup 6}Li,{sup 6}He) reaction was studied on the nuclei {sup 37}Cl and {sup 71}Ga at {ital E}{sub 6Li}=156 MeV at extreme forward angles including zero degree. Gamow-Teller strength and the corresponding {ital B}(GT) values were extracted. It is shown that these measurements provide an alternative method to calibrate solar neutrino detectors.

  16. SEISMIC AND DYNAMICAL SOLAR MODELS. I. THE IMPACT OF THE SOLAR ROTATION HISTORY ON NEUTRINOS AND SEISMIC INDICATORS

    SciTech Connect

    Turck-Chieze, S.; Palacios, A.; Nghiem, P. A. P.

    2010-06-01

    Solar activity and helioseismology show the limitation of the standard solar model and call for the inclusion of dynamical processes in both convective and radiative zones. In this paper, we concentrate on the radiative zone. We first recall the sensitivity of boron neutrinos to the microscopic physics included in solar standard and seismic models. We confront the neutrino predictions of the seismic model with all the detected neutrino fluxes. Then, we compute new models of the Sun including a detailed transport of angular momentum and chemicals due to internal rotation that includes meridional circulation and shear-induced turbulence. We use two stellar evolution codes: CESAM and STAREVOL to estimate the different terms. We follow three temporal evolutions of the internal rotation which differ by their initial conditions: very slow, moderate, and fast rotation, with magnetic braking at the arrival on the main sequence for the last two. We find that the meridional velocities in the present solar radiative zone are extremely small in comparison with those of the convective zone (smaller than 10{sup -6} cm s{sup -1} instead of m s{sup -1}). All models lead to a radial differential rotation profile in the radiative zone but with a significantly different contrast. We compare these profiles to the presumed solar internal rotation and show that if meridional circulation and shear turbulence were the only mechanisms transporting angular momentum within the Sun, a rather slow rotation in the young Sun is favored. We confirm the small influence of the transport by rotation on the sound speed profile but its potential impact on the chemicals in the transition region between radiation and convective zones. These models are physically more representative of the real Sun than the standard or seismic solar models but a high initial rotation, as has been considered previously, increases the disagreement with neutrinos and the sound speed in the radiative zone. This present work

  17. Solar neutrino event spectra: Tuning SNO to equalize Super-Kamiokande

    NASA Astrophysics Data System (ADS)

    Fogli, G. L.; Lisi, E.; Palazzo, A.; Villante, F. L.

    2001-06-01

    The Super-Kamiokande (SK) and the Sudbury Neutrino Observatory (SNO) experiments are monitoring the flux of 8B solar neutrinos through the electron energy spectrum from the reactions νe,μ,τ+e- -->νe,μ,τ+e- and νe+d-->p+p+e-, respectively. We show that the SK detector response to 8B neutrinos in each bin of the electron energy spectrum (above 8 MeV) can be approximated, with good accuracy, by the SNO detector response in an appropriate electron energy range (above 5.1 MeV). For instance, the SK response in the bin [10, 10.5] MeV is reproduced (``equalized'') within ~2% by the SNO response in the range [7.1, 11.75] MeV. As a consequence, in the presence of active neutrino oscillations, the SK and SNO event rates in the corresponding energy ranges turn out to be linearly related, for any functional form of the oscillation probability. Such equalization is not spoiled by the possible contribution of hep neutrinos (within current phenomenological limits). In perspective, when the SK and the SNO spectra will both be measured with high accuracy, the SK-SNO equalization can be used to determine the absolute 8B neutrino flux, and to cross-check the (non)observation of spectral deviations in SK and SNO. At present, as an exercise, we use the equalization to ``predict'' the SNO energy spectrum, on the basis of the current SK data. Finally, we briefly discuss some modifications or limitations of our results in the case of sterile ν oscillations and of relatively large Earth matter effects.

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

    NASA Technical Reports Server (NTRS)

    Proffitt, Charles R.

    1994-01-01

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

  19. Neutrino masses, neutrino oscillations, and cosmological implications

    NASA Technical Reports Server (NTRS)

    Stecker, F. W.

    1982-01-01

    Theoretical concepts and motivations for considering neutrinos having finite masses are discussed and the experimental situation on searches for neutrino masses and oscillations is summarized. The solar neutrino problem, reactor, deep mine and accelerator data, tri decay experiments and double beta-decay data are considered and cosmological implications and astrophysical data relating to neutrino masses are reviewed. The neutrino oscillation solution to the solar neutrino problem, the missing mass problem in galaxy halos and galaxy cluster galaxy formation and clustering, and radiative neutrino decay and the cosmic ultraviolet background radiation are examined.

  20. Solar {sup 8}B and hep Neutrino Measurements from 1258 Days of Super-Kamiokande Data

    SciTech Connect

    Fukuda, S.; Fukuda, Y.; Ishitsuka, M.; Itow, Y.; Kajita, T.; Kameda, J.; Kaneyuki, K.; Kobayashi, K.; Koshio, Y.; Miura, M.

    2001-06-18

    Solar neutrino measurements from 1258days of data from the Super-Kamiokande detector are presented. The measurements are based on recoil electrons in the energy range 5.0{endash}20.0MeV. The measured solar neutrino flux is 2.32{+-}0.03(stat){sup +0.08}{sub {minus}0.07}(syst){times}10{sup 6} cm{sup {minus}2}s{sup {minus}1} , which is 45.1{+-}0.5(stat ){sup +1.6}{sub {minus}1.4}(syst) % of that predicted by the BP2000 SSM. The day vs night flux asymmetry ({Phi}{sub n}{minus}{Phi}{sub d})/ {Phi}{sub average} is 0.033{+-}0.022(stat){sup +0.013}{sub {minus}0.012}(syst) . The recoil electron energy spectrum is consistent with no spectral distortion. For the hep neutrino flux, we set a 90% C.L.upper limit of 40{times}10{sup 3} cm{sup {minus}2}s{sup {minus}1} , which is 4.3times the BP2000 SSM prediction.

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

    NASA Astrophysics Data System (ADS)

    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.

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

    SciTech Connect

    West, G.B. )

    1989-01-01

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

  3. The sun shines brightest at night: Reflections on the solar neutrino problem

    NASA Astrophysics Data System (ADS)

    Robertson, R. G. H. (Hamish)

    2016-03-01

    The flux of neutrinos from the sun's core depends on the rate at which the sun produces energy, a testable prediction as Ray Davis realized in the early 1960s. How that test turned out is one of the best-known and most dramatic stories in physics. With the hindsight of our current understanding, it is interesting to look back at the experimental and theoretical steps that led to the disclosure of new properties of nature. It was a truly international adventure, but the US played a particularly strong role in these achievements. The study of solar neutrinos continues to offer tantalizing scientific rewards, and we conclude with a look at what the future might hold.

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

    NASA Astrophysics Data System (ADS)

    Joshipura, Anjan S.; Patel, Ketan M.

    2014-08-01

    Flavor symmetries appropriate for describing a neutrino spectrum with degenerate solar pair and a third massive or massless neutrino are discussed. We demand that the required residual symmetries of the leptonic mass matrices be subgroups of some discrete symmetry group Gf. Gf can be a subgroup of SU(3) if the third neutrino is massive and we derive general results on the mixing angle predictions for various discrete subgroups of SU(3) divided into the two classes, called type C and D in Miller et al. [Theory and Applications of Finite Groups (John Wiley & Sons, New York, 1916)]. The main results are (a) All the SU(3) subgroups of type C fail in simultaneously giving correct θ13 and θ23. (b) All the groups of type D can predict a relation cos2θ13sin2θ23=1/3 among the mixing angles which appears to be a good zeroth order approximation. Among these, various Δ(6n2) groups with n ≥8 can simultaneously lead also to sin2θ13 in agreement with global fit at 3σ. (c) The group Σ(168)≅PSL(2,7) predicts near to the best fit value for θ13 and θ23 within the 1σ range. All discrete subgroups of U(3) with order <512 and having three-dimensional irreducible representation are considered as possible Gf when the third neutrino is massless. Only seven of them are shown to be viable and three of these can correctly predict θ13 and/or θ23. The solar angle remains undetermined at the leading order in all the cases due to degeneracy in the masses. A class of general perturbations which can correctly reproduce all the observables is discussed in the context of several groups which offer good leading order predictions.

  5. Neutrino Detectors

    NASA Astrophysics Data System (ADS)

    von Feilitzsch, Franz; Lanfranchi, Jean-Côme; Wurm, Michael

    The neutrino was postulated by Wolfgang Pauli in the early 1930s, but could only be detected for the first time in the 1950s. Ever since scientists all around the world have worked on the detection and understanding of this particle which so scarcely interacts with matter. Depending on the origin and nature of the neutrino, various types of experiments have been developed and operated. In this entry, we will review neutrino detectors in terms of neutrino energy and associated detection technique as well as the scientific outcome of some selected examples. After a brief historical introduction, the detection of low-energy neutrinos originating from nuclear reactors or from the Earth is used to illustrate the principles and difficulties which are encountered in detecting neutrinos. In the context of solar neutrino spectroscopy, where the neutrino is used as a probe for astrophysics, three different types of neutrino detectors are presented - water Čerenkov, radiochemical, and liquid-scintillator detectors. Moving to higher neutrino energies, we discuss neutrinos produced by astrophysical sources and from accelerators. The entry concludes with an overview of a selection of future neutrino experiments and their scientific goals.

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

    SciTech Connect

    Turck-Chieze, S.; Garcia, R. A.; Ballot, J.; Couvidat, S.; Mathur, S.; Salabert, D.; Silk, J.

    2012-02-10

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

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

    NASA Technical Reports Server (NTRS)

    Hampel, W.; Kiko, J.; Heusser, G.; Huebner, M.; 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.

  8. A Possible Role of Neutrinos in Stimulating Beta Decays and its Significance for Solar Physics

    NASA Astrophysics Data System (ADS)

    Sturrock, Peter A.; Fischbach, Ephraim; Jenkins, Jere

    2014-06-01

    We find evidence from measurements of Ag108, Ba133, Eu152, Eu154, Ra226 and Sr90 (Physikalisch-Technische Bundesanstalt, Germany), Rn222 (Geological Survey of Israel), Co60, Pu239, and Sr90 (Lomonosov Moscow State University, Russia), Cl36 and Si32 (Brookhaven National Laboratory, USA) and Mn54 (Purdue University, USA) that beta-decay rates tend to be variable, and that the Sun is responsible for some - perhaps all - of the variability. One variation is an annual oscillation with amplitude about 0.1% and maximum in January or February, presumably related to the annually varying Sun-Earth distance. We also find evidence for two rotational modulations, one with a measured (synodic) frequency of about 12.5 year-1 (an absolute, sidereal frequency of 13.5 year-1), due perhaps to processes in the radiative zone, and another with a synodic frequency of about 11 year-1 (12 year-1 sidereal), due perhaps to processes in an inner tachocline between the core and the radiative zone. A steep gradient in angular velocity (as in a tachocline) is known to be unstable and generate r-mode oscillations. These may be detectable as Rieger-type oscillations in the outer tachocline, and to similar oscillations (with correspondingly lower frequencies, in proportion to the sidereal rotation frequencies) in the inner tachocline. We find evidence for such r-mode oscillations not only in beta-decay data, but also in solar diameter data. A possible explanation of the apparent beta-decay variability is that decays may be stimulated by neutrinos. Since the flavor composition of the neutrino flux can be modified by the Sun’s internal magnetic field (via Resonant Spin Flavor Precession), magnetohydrodynamic processes in the deep solar interior may be detectable on Earth as neutrino-stimulated beta-decay fluctuations. Experiments suggest that a nuclide such as 32Si has a beta-decay-equivalent-cross-section of order 10-25 cm2, larger than the neutrino-equivalent-cross-section of an electron or

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

    SciTech Connect

    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.

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

    SciTech Connect

    Lanou, Robert E., Jr.

    2006-03-31

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

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

    SciTech Connect

    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.

  12. Neutrino Oscillations and the Sudbury Neutrino Observatory

    NASA Astrophysics Data System (ADS)

    Wark, David

    2001-04-01

    When the existence of the neutrino was almost apologetically first proposed by Wolfgang Pauli it was intended to explain the mysterious apparent absence of energy and momentum in beta decay. 70 years later the neutrino has indeed solved that mystery, but it has generated still more of its own. Are neutrinos massive? Is it possible to create a neutrino with its spin in the same direction as its momentum? What fraction of the mass of the Universe is made up of neutrinos? Are the flavour labels which we put on neutrinos, like electron and muon, really fixed or can they change? Why does no experiment see the predicted flux of neutrinos from the Sun? Why do there appear to be roughly equal numbers of muon and electron neutrinos created in our atmosphere, rather than the 2:1 ratio we would expect? Many of these questions were coupled when Bruno Pontecorvo first suggested that the shortfall in solar neutrino measurements were caused by neutrino oscillations - neutrinos spontaneously changing flavour as they travel from the Sun. 30 years later we still await definitive proof of that conjecture, and providing that proof is the reason for the Sudbury Neutrino Observatory. The talk will discuss the current state of neutrino oscillations studies, and show how the unique capabilities of the Sudbury Neutrino Observatory can provide definitive proof of whether neutrino oscillations are the long-sought answer to the solar neutrino problem.

  13. NEUTRINO FACTORIES - PHYSICS POTENTIALS.

    SciTech Connect

    PARSA,Z.

    2001-02-16

    The recent results from Super-Kamiokande atmospheric and solar neutrino observations opens a new era in neutrino physics and has sparked a considerable interest in the physics possibilities with a Neutrino Factory based on the muon storage ring. We present physics opportunities at a Neutrino Factory, and prospects of Neutrino oscillation experiments. Using the precisely known flavor composition of the beam, one could envision an extensive program to measure the neutrino oscillation mixing matrix, including possible CP violating effects. These and Neutrino Interaction Rates for examples of a Neutrino Factory at BNL (and FNAL) with detectors at Gran Sasso, SLAC and Sudan are also presented.

  14. Development and Operation of a Liquid Scintillator Purification System for a Solar Neutrino Detector

    NASA Astrophysics Data System (ADS)

    Chen, M.; Benziger, J. B.; Calaprice, F. P.; Darnton, N.; Johnson, M.; Loeser, F.; Vogelaar, R. B.

    1996-10-01

    An on-line purification system for a large-scale, liquid scintillator detector has been developed for the Counting Test Facility (CTF), a five-ton prototype of the Borexino solar neutrino detector at Gran Sasso. This purification system was operated to remove radioactive impurities from the pseudocumene-based scintillator in the CTF. Counter-current water extraction was performed to remove ionic impurities from the scintillator. Notably, the radon daughters ^210Bi and ^210Po were identified prior to purification and were successfully removed by water extraction. Vacuum distillation of the entire scintillator mixture allowed high radiopurity and chemical purity to be maintained; in addtion, it enabled a test of the origin of ^14C in the scintillator mixture to be performed. Finally, nitrogen stripping was utilized to remove noble gas radioactive isotopes, such as ^85Kr and ^222Rn. The results of the CTF purification activities and an overview of the purification scheme for the Borexino solar neutrino experiment will be presented.

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

    SciTech Connect

    Villante, Francesco L.; Serenelli, Aldo M.; Delahaye, Franck; Pinsonneault, Marc H.

    2014-05-20

    We perform a quantitative analysis of the solar composition problem by using a statistical approach that allows us to combine the information provided by helioseismic and solar neutrino data in an effective way. We include in our analysis the helioseismic determinations of the surface helium abundance and of the depth of the convective envelope, the measurements of the {sup 7}Be and {sup 8}B neutrino fluxes, and the sound speed profile inferred from helioseismic frequencies. We provide all the ingredients to describe how these quantities depend on the solar surface composition, different from the initial and internal composition due to the effects of diffusion and nuclear reactions, and to evaluate the (correlated) uncertainties in solar model predictions. We include error sources that are not traditionally considered such as those from inversion of helioseismic data. We, then, apply the proposed approach to infer the chemical composition of the Sun. Our result is that the opacity profile of the Sun is well constrained by the solar observational properties. In the context of a two-parameter analysis in which elements are grouped as volatiles (i.e., C, N, O, and Ne) and refractories (i.e., Mg, Si, S, and Fe), the optimal surface composition is found by increasing the abundance of volatiles by (45 ± 4)% and that of refractories by (19 ± 3)% with respect to the values provided by Asplund et al. (2009, ARA and A, 47, 481). This corresponds to the abundances ε{sub O} = 8.85 ± 0.01 and ε{sub Fe} = 7.52 ± 0.01, which are consistent at the ∼1σ level with those provided by Grevesse and Sauval (1998, SSRv, 85, 161). As an additional result of our analysis, we show that the best fit to the observational data is obtained with values of input parameters of the standard solar models (radiative opacities, gravitational settling rate, and the astrophysical factors S {sub 34} and S {sub 17}) that differ at the ∼1σ level from those presently adopted.

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

    NASA Technical Reports Server (NTRS)

    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.

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

    SciTech Connect

    1995-04-01

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

  18. Low-energy neutrinos

    NASA Astrophysics Data System (ADS)

    Ludhova, Livia

    2016-05-01

    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 field of solar neutrinos, geoneutrinos, and the search for sterile neutrino with artificial neutrino sources is provided here; other neutrino sources, as for example reactor or high-energy neutrinos, are described elsewhere. For each of these three fields, the present-day motivation and open questions, as well as the latest experimental results and future perspectives are discussed.

  19. Search for modulations of the solar {sup 7}Be flux in the next-generation neutrino observatory LENA

    SciTech Connect

    Wurm, Michael; Feilitzsch, Franz von; Goeger-Neff, Marianne; Lewke, Timo; Meindl, Quirin; Moellenberg, Randolph; Oberauer, Lothar; Potzel, Walter; Tippmann, Marc; Winter, Juergen; Caccianiga, Barbara; D'Angelo, Davide; Lombardi, Paolo; Ludhova, Livia; Meroni, Emanuela; Miramonti, Lino; Ranucci, Gioacchino; Davini, Stefano; Lachenmaier, Tobias

    2011-02-01

    A next-generation liquid-scintillator detector will be able to perform high-statistics measurements of the solar neutrino flux. In LENA, solar {sup 7}Be neutrinos are expected to cause 1.7x10{sup 4} electron recoil events per day in a fiducial volume of 35 kilotons. Based on this signal, a search for periodic modulations on a subpercent level can be conducted, surpassing the sensitivity of current detectors by at least a factor of 20. The range of accessible periods reaches from several minutes, corresponding to modulations induced by helioseismic g-modes, to tens of years, allowing to study long-term changes in solar fusion rates.

  20. A GaAs DETECTOR FOR DARK MATTER AND SOLAR NEUTRINO RESEARCH

    SciTech Connect

    T. BOWLES; ET AL

    2000-08-01

    The ability to produce large GaAs crystals with the requisite electronic properties to be fabricated into charged particle and photon detectors would provide a detector medium that would find numerous applications in both applied and fundamental research. Various applications would likely include x-ray detectors on satellites, environmental monitoring, medical imaging, bore hole mining spectroscopy, searches for dark matter, and solar neutrino research. We have carried out the development of GaAs detectors using two commercial crystal growing techniques. We have shown it should be able to grow detectors with 20 cm{sup 2} area and a depletion depth of 1 mm. Detectors of this size would find immediate applications in high-resolution, room temperature, low energy gamma ray measurements. We have also arrived at an understanding of the limitations of the common techniques used to grow GaAs and have determined that it should be possible to produce larger detectors using proprietary methods.

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

    SciTech Connect

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

    1990-12-01

    We report on work accomplished in the first 30 months of a research and development program to investigate the feasibility of a new technique to detect solar neutrinos in superfluid helium. Accomplishments include the successful completion of design, construction and operation of the entire cryogenic, mechanical and electronic apparatus. During the last several months we have begun a series of experiments in superfluid helium to test the method. Experimental results include the first observation of the combined physical processes essential to the detection technique: ballistic roton generation by energetic charged particles, quantum evaporation of helium at a free surface and bolometric detection of the evaporated helium by physisorption on a cold silicon wafer. Additional results are also presented.

  2. Determination of the {nu}{sub e} and total {sup 8}B solar neutrino fluxes using the Sudbury Neutrino Observatory Phase I data set

    SciTech Connect

    Aharmim, B.; Bigu, J.; Cowan, J. H. M.; Farine, J.; Fleurot, F.; Hallman, E. D.; Haq, R. U.; Hewett, J.; Hykaway, J. G.; Krueger, A.; Luoma, S.; Roberge, A.; Saettler, E.; Schwendener, M. H.; Tafirout, R.; Virtue, C. J.; Ahmad, Q. R.; Bullard, T. V.; Burritt, T. H.; Cox, G. A.

    2007-04-15

    This article provides the complete description of results from the Phase I data set of the Sudbury Neutrino Observatory (SNO). The Phase I data set is based on a 0.65 kiloton-year exposure of {sup 2}H{sub 2}O (in the following denoted as D{sub 2}O) to the solar {sup 8}B neutrino flux. Included here are details of the SNO physics and detector model, evaluations of systematic uncertainties, and estimates of backgrounds. Also discussed are SNO's approach to statistical extraction of the signals from the three neutrino reactions (charged current, neutral current, and elastic scattering) and the results of a search for a day-night asymmetry in the {nu}{sub e} flux. Under the assumption that the {sup 8}B spectrum is undistorted, the measurements from this phase yield a solar {nu}{sub e} flux of {phi}({nu}{sub e})=1.76{sub -0.05}{sup +0.05}(stat.){sub -0.09}{sup +0.09}(syst.)x10{sup 6} cm{sup -2} s{sup -1} and a non-{nu}{sub e} component of {phi}({nu}{sub {mu}}{sub {tau}})=3.41{sub -0.45}{sup +0.45}(stat.){sub -0.45}{sup +0.48}(syst.)x10{sup 6} cm{sup -2} s{sup -1}. The sum of these components provides a total flux in excellent agreement with the predictions of standard solar models. The day-night asymmetry in the {nu}{sub e} flux is found to be A{sub e}=7.0{+-}4.9(stat.){sub -1.2}{sup +1.3}%(syst.), when the asymmetry in the total flux is constrained to be zero.

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

    SciTech Connect

    Barger, V.; Marfatia, D.; Whisnant, K.; Wood, B. P.

    2001-10-01

    We analyze the 1258-day Super-Kamiokande day and night solar neutrino energy spectra with various {chi}{sup 2} definitions. The best-fit lies in the large mixing angle (LMA) region at ({Delta}m{sup 2},tan{sup 2}{theta})=(5.01 x 10{sup -5} eV{sup 2},0.60), independently of whether systematic errors are included in the {chi}{sup 2} 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 ({Delta}m{sup 2},tan{sup 2}{theta})=(5.01 x 10{sup -5} eV{sup 2},0.56).

  4. Sterile neutrinos

    NASA Astrophysics Data System (ADS)

    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.

  5. Neutrino astronomy

    SciTech Connect

    Schramm, D.N.

    1980-01-01

    Current knowledge and proposed experiments in the field of neutrino astronomy are reviewed, with particular emphasis on expected sources and existing and proposed detectors for intermediate-energy (10 to 50 MeV) and ultrahigh energy (greater than 10 GeV) neutrinos. Following a brief discussion of the counting rate obtained in the solar neutrino experiment of Davis (1978) and possible statistical sources for the discrepancy between the expected and observed rates, consideration is given to the physics of neutrino ejection in stellar gravitational collapse and sources of high-energy proton collisions giving rise to ultrahigh energy neutrinos. The capabilities of operating Cerenkov detectors at the Homestake Gold Mine, the Mt. Blanc Tunnel and in the Soviet Caucasus are considered in relation to the detection of gravitational collapse in the center of the galaxy, and it is pointed out that neutrino detectors offer a more reliable means of detecting collapses in the Galaxy than do gravitational wave detectors. The possibility of using Cerenkov detectors for ultrahigh energy neutrino detection is also indicated, and applications of large neutrino detectors such as the proposed DUMAND array to measure the lifetime of the proton are discussed.

  6. Neutrino Detectors Review

    SciTech Connect

    D'Ambrosio, Nicola

    2005-10-12

    The neutrino physics is one of the most important research field and there are several experiments made and under construction focused on it. This paper will present a review on some detectors used for Solar Neutrinos detection, Atmospheric Neutrinos detection and in Long Baseline Experiments.

  7. Neutrino observations from the Sudbury Neutrino Observatory

    SciTech Connect

    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

    DOE R&D Accomplishments Database

    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. Summary: Neutrinos and nonaccelerator physics

    SciTech Connect

    Hoffman, C.M.

    1991-01-01

    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. (LSP)

  10. Novel Ideas for Neutrino Beams

    SciTech Connect

    Peach, Ken

    2007-04-23

    Recent developments in neutrino physics, primarily the demonstration of neutrino oscillations in both atmospheric neutrinos and solar neutrinos, provide the first conclusive evidence for physics beyond the Standard Model of particle physics. The simplest phenomenology of neutrino oscillations, for three generations of neutrino, requires six parameters - two squared mass differences, 3 mixing angles and a complex phase that could, if not 0 or {pi}, contribute to the otherwise unexplained baryon asymmetry observed in the universe. Exploring the neutrino sector will require very intense beams of neutrinos, and will need novel solutions.

  11. Neutrino oscillation studies with reactors.

    PubMed

    Vogel, P; Wen, L J; Zhang, C

    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 flavours 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 θ13. In the near future, reactors will help to determine the neutrino mass hierarchy and to solve the puzzling issue of sterile neutrinos. PMID:25913819

  12. Neutrino oscillation studies with reactors

    DOE PAGESBeta

    Vogel, P.; Wen, L.J.; Zhang, C.

    2015-04-27

    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 flavours 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 θ13. In the near future, reactors will help to determine the neutrino mass hierarchy and to solve the puzzling issue of sterile neutrinos.

  13. Neutrino oscillation studies with reactors

    PubMed Central

    Vogel, P.; Wen, L.J.; Zhang, C.

    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 flavours 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 θ13. In the near future, reactors will help to determine the neutrino mass hierarchy and to solve the puzzling issue of sterile neutrinos. PMID:25913819

  14. Neutrino oscillation studies with reactors

    SciTech Connect

    Vogel, P.; Wen, L.J.; Zhang, C.

    2015-04-27

    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 flavours 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 θ13. In the near future, reactors will help to determine the neutrino mass hierarchy and to solve the puzzling issue of sterile neutrinos.

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

    SciTech Connect

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

    2009-07-15

    The Russian-American experiment SAGE began to measure the solar neutrino capture rate with a target of gallium metal in December 1989. Measurements have continued with only a few brief interruptions since that time. In this article we present the experimental improvements in SAGE since its last published data summary in December 2001. Assuming the solar neutrino production rate was constant during the period of data collection, combined analysis of 168 extractions through December 2007 gives a capture rate of solar neutrinos with energy more than 233 keV of 65.4{sub -3.0}{sup +3.1} (stat) {sub -2.8}{sup +2.6} (syst) SNU. The weighted average of the results of all three Ga solar neutrino experiments, SAGE, Gallex, and GNO, is now 66.1{+-}3.1 SNU, where statistical and systematic uncertainties have been combined in quadrature. During the recent period of data collection a new test of SAGE was made with a reactor-produced {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 0.87{+-}0.05. A probable explanation for this low result is that the cross section for neutrino capture by the two lowest-lying excited states in {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 SNU to 66 SNU with an uncertainty of about 4%, in good agreement with experiment. We derive the current value of the neutrino flux produced in the Sun by the proton-proton fusion reaction to be {phi}{sub pp}{sup {center_dot}}=(6.0{+-}0.8)x10{sup 10}/(cm{sup 2} s), which agrees well with the pp flux predicted by the standard solar model. Finally, we make several tests and show that the data are consistent with the assumption that the solar neutrino production rate is constant in time.

  16. Precision measurement of the 7Be solar neutrino flux and its day-night asymmetry with Borexino

    NASA Astrophysics Data System (ADS)

    Caccianiga, Barbara; 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.; D'Angelo, D.; Davini, S.; Derbin, A.; Etenko, A.; Fomenko, K.; Franco, D.; Galbiati, C.; Gazzana, S.; Ghiano, C.; Giammarchi, M.; Goeger-Neff, M.; Goretti, A.; Grandi, L.; Guardincerri, E.; Hardy, S.; Ianni, Aldo; Ianni, Andrea; Korablev, D.; Korga, G.; Koshio, Y.; Kryn, D.; Laubenstein, M.; Lewke, T.; Litvinovich, E.; Loer, B.; Lombardi, P.; Lombardi, L.; 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

    Borexino measures the 7Be solar neutrino flux on 740 live days of data-taking to be 46±1.5+1.6-1.5 events/(day · 100 tons) which corresponds to an equivalent unoscillated flux on Earth of (3.11±0.10+0.11-0.10)·109sec -1 cm-2. This result excludes the no-oscillation hypothesis at 5 σ and provides a precise measurement of the survival probability Pee in the vacuum dominated oscillation regime Pee = 0.51±0.07. Borexino also measures the day-night asymmetry of the 7Be neutrino rate with a total error of 1.4% and finds it to be consistent with zero. This result is in agreement with the MSW-LMA hypothesis and disfavours at more than 8.5 σ the so-called LOW region of the oscillation parameter space.

  17. Measurement of the solar B8 neutrino rate with a liquid scintillator target and 3 MeV energy threshold in the Borexino detector

    NASA Astrophysics Data System (ADS)

    Bellini, G.; Benziger, J.; Bonetti, S.; Buizza Avanzini, M.; Caccianiga, B.; Cadonati, L.; Calaprice, F.; Carraro, C.; Chavarria, A.; Chepurnov, A.; Dalnoki-Veress, F.; D'Angelo, D.; Davini, S.; de Kerret, H.; Derbin, A.; Etenko, A.; Fomenko, K.; Franco, D.; Galbiati, C.; Gazzana, S.; Ghiano, C.; Giammarchi, M.; Goeger-Neff, M.; Goretti, A.; Guardincerri, E.; Hardy, S.; Ianni, Aldo; Ianni, Andrea; Joyce, M.; 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.; Meindl, Q.; Meroni, E.; Miramonti, L.; Misiaszek, M.; Montanari, D.; Muratova, V.; Oberauer, L.; Obolensky, M.; Ortica, F.; Pallavicini, M.; Papp, L.; Perasso, L.; Perasso, S.; Pocar, A.; Raghavan, R. S.; Ranucci, G.; Razeto, A.; Re, A.; 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.; Winter, J.; Wojcik, M.; Wright, A.; Wurm, M.; Xu, J.; Zaimidoroga, O.; Zavatarelli, S.; Zuzel, G.; Borexino Collaboration

    2010-08-01

    We report the measurement of ν-e elastic scattering from B8 solar neutrinos with 3 MeV energy threshold by the Borexino detector in Gran Sasso (Italy). The rate of solar neutrino-induced electron scattering events above this energy in Borexino is 0.22±0.04(stat)±0.01(syst)cpd/100t, which corresponds to ΦB8ES=2.4±0.4±0.1×106cm-2s-1, in good agreement with measurements from SNO and SuperKamiokaNDE. Assuming the B8 neutrino flux predicted by the high metallicity standard solar model, the average B8 νe survival probability above 3 MeV is measured to be 0.29±0.10. The survival probabilities for Be7 and B8 neutrinos as measured by Borexino differ by 1.9σ. These results are consistent with the prediction of the MSW-LMA solution of a transition in the solar νe survival probability Pee between the low-energy vacuum-driven and the high-energy matter-enhanced solar neutrino oscillation regimes.

  18. Global analyses of neutrino oscillation experiments

    NASA Astrophysics Data System (ADS)

    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.

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

    NASA Astrophysics Data System (ADS)

    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

  20. The Sudbury Neutrino Observatory

    NASA Astrophysics Data System (ADS)

    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.

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

    NASA Astrophysics Data System (ADS)

    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.

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

    NASA Astrophysics Data System (ADS)

    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.

  3. Core-collapse Supernovae from 9 to 120 Solar Masses Based on Neutrino-powered Explosions

    NASA Astrophysics Data System (ADS)

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

    2016-04-01

    Nucleosynthesis, light curves, explosion energies, and remnant masses are calculated for a grid of supernovae (SNe) resulting from massive stars with solar metallicity and masses from 9.0 to 120 {M}ȯ . 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 five standard progenitors, and for the Crab SN using a 9.6 {M}ȯ progenitor. As a result of using a calibrated central engine, the final kinetic energy of the SN is variable and sensitive to the structure of each pre-SN star. Many progenitors with extended core structures do not explode, but become black holes (BHs), 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 SNe Ia is also allowed, but with a deficiency of light s-process isotopes. The resulting neutron star initial mass function has a mean gravitational mass near 1.4 {M}ȯ . The average BH mass is about 9 {M}ȯ if only the helium core implodes, and 14 {M}ȯ if the entire pre-SN star collapses. Only ∼10% of SNe come from stars over 20 {M}ȯ , and some of these are Type Ib or Ic. Some useful systematics of Type IIp light curves are explored.

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

    NASA Astrophysics Data System (ADS)

    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.

  5. Nucleosynthesis and Neutrinos

    SciTech Connect

    Kajino, Toshitaka

    2011-05-06

    Neutrinos play the critical roles in nucleosynthesis of light-to-heavy mass nuclei in core-collapse supernovae. We study the nucleosynthesis induced by neutrino interactions and find suitable average neutrino temperatures in order to explain the observed solar system abundances of several isotopes {sup 7}Li, {sup 11}B, {sup 138}La and {sup 180}Ta. These isotopes are predominantly synthesized by the supernova {nu}-process. We also study the neutrino oscillation effects on their abundances and propose a method to determine the unknown neutrino oscillation parameters, i.e. {theta}{sub 13} and mass hierarchy.

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

    SciTech Connect

    Cooper, N.G.

    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.

  7. Los Alamos Science, Number 25 -- 1997: Celebrating the Neutrino

    DOE R&D Accomplishments Database

    Cooper, N. G. ed.

    1997-01-01

    This issue is devoted to the neutrino and its remaining mysteries. It is divided into the following areas: (1) The Reines-Cowan experiment -- detecting the poltergeist; (2) The oscillating neutrino -- an introduction to neutrino masses and mixing; (3) A brief history of neutrino experiments at LAMPF; (4) A thousand eyes -- the story of LSND (Los Alamos neutrino oscillation experiment); (5) The evidence for oscillations; (6) The nature of neutrinos in muon decay and physics beyond the Standard Model; (7) Exorcising ghosts -- in pursuit of the missing solar neutrinos; (8) MSW -- a possible solution to the solar neutrino problem; (8) Neutrinos and supernovae; and (9) Dark matter and massive neutrinos.

  8. Neutrino Mass Anarchy

    NASA Astrophysics Data System (ADS)

    Hall, Lawrence; Murayama, Hitoshi; Weiner, Neal

    2000-03-01

    What is the form of the neutrino mass matrix which governs the oscillations of the atmospheric and solar neutrinos? Features of the data have led to a dominant viewpoint where the mass matrix has an ordered, regulated pattern, perhaps dictated by a flavor symmetry. We challenge this viewpoint and demonstrate that the data are well accounted for by a neutrino mass matrix which appears to have random entries.

  9. Neutrino mass anarchy

    PubMed

    Hall; Murayama; Weiner

    2000-03-20

    What is the form of the neutrino mass matrix which governs the oscillations of the atmospheric and solar neutrinos? Features of the data have led to a dominant viewpoint where the mass matrix has an ordered, regulated pattern, perhaps dictated by a flavor symmetry. We challenge this viewpoint and demonstrate that the data are well accounted for by a neutrino mass matrix which appears to have random entries. PMID:11017272

  10. Neutrino physics with JUNO

    NASA Astrophysics Data System (ADS)

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

    2016-03-01

    The Jiangmen Underground Neutrino Observatory (JUNO), a 20 kton multi-purpose underground liquid scintillator detector, was proposed with the determination of the neutrino mass hierarchy (MH) as a primary physics goal. The excellent energy resolution and the large fiducial volume anticipated for the JUNO detector offer exciting opportunities for addressing many important topics in neutrino and astro-particle physics. In this document, we present the physics motivations and the anticipated performance of the JUNO detector for various proposed measurements. Following an introduction summarizing the current status and open issues in neutrino physics, we discuss how the detection of antineutrinos generated by a cluster of nuclear power plants allows the determination of the neutrino MH at a 3-4σ significance with six years of running of JUNO. The measurement of antineutrino spectrum with excellent energy resolution will also lead to the precise determination of the neutrino oscillation parameters {{sin}}2{θ }12, {{Δ }}{m}212, and | {{Δ }}{m}{ee}2| to an accuracy of better than 1%, which will play a crucial role in the future unitarity test of the MNSP matrix. The JUNO detector is capable of observing not only antineutrinos from the power plants, but also neutrinos/antineutrinos from terrestrial and extra-terrestrial sources, including supernova burst neutrinos, diffuse supernova neutrino background, geoneutrinos, atmospheric neutrinos, and solar neutrinos. As a result of JUNO's large size, excellent energy resolution, and vertex reconstruction capability, interesting new data on these topics can be collected. For example, a neutrino burst from a typical core-collapse supernova at a distance of 10 kpc would lead to ˜5000 inverse-beta-decay events and ˜2000 all-flavor neutrino-proton ES events in JUNO, which are of crucial importance for understanding the mechanism of supernova explosion and for exploring novel phenomena such as collective neutrino oscillations

  11. Results from Neutrino Oscillations Experiments

    SciTech Connect

    Aguilar-Arevalo, Alexis

    2010-09-10

    The interpretation of the results of early solar and atmospheric neutrino experiments in terms of neutrino oscillations has been verified by several recent experiments using both, natural and man-made sources. The observations provide compelling evidence in favor of the existence of neutrino masses and mixings. These proceedings give a general description of the results from neutrino oscillation experiments, the current status of the field, and some possible future developments.

  12. Bolometric detection of neutrinos

    NASA Technical Reports Server (NTRS)

    Cabrera, B.; Krauss, L. M.; Wilczek, F.

    1985-01-01

    Elastic neutrino scattering off electrons in crystalline silicon at 1-10 mK results in measurable temperature changes in macroscopic amounts of material, even for low-energy (less than 0.41-MeV) pp neutrinos from the sun. New detectors for bolometric measurement of low-energy neutrino interactions, including coherent nuclear elastic scattering, are proposed. A new and more sensitive search for oscillations of reactor antineutrinos is practical (about 100 kg of Si), and would lay the groundwork for a more ambitious measurement of the spectrum of pp, Be-7, and B-8 solar neutrinos, and of supernovae anywhere in the Galaxy (about 10 tons of Si).

  13. Why is the neutrino oscillation formula expanded in Δ m {21/2}/Δ m {31/2} still accurate near the solar resonance in matter?

    NASA Astrophysics Data System (ADS)

    Xu, Xun-Jie

    2015-10-01

    The conventional approximate formula for neutrino oscillation in matter which is obtained from the expansion in terms of the ratio of mass square differences α = Δ m 21 2 /Δ m 31 2 ≈ 0.03, first proposed by Cervera, et al. and Freund, turns out to be an accurate formula for accelerator neutrino experiments. Originally it required the neutrino energy to be well above the solar resonance to validate the expansion but it is found to be still very accurate when the formula is extrapolated to the resonance, which is practically important for the T2K experiment. This paper shows that the accuracy is guaranteed by cancellations of branch cut singularities and also, for the first time, analytically computes the actual error of the formula. The actual error implies that the original requirement can be safely removed in current experiments.

  14. Sudbury Neutrino Observatory

    NASA Astrophysics Data System (ADS)

    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.

  15. EFFECTS OF A DEEP MIXED SHELL ON SOLAR g-MODES, p-MODES, AND NEUTRINO FLUX

    SciTech Connect

    Wolff, Charles L.

    2009-08-10

    A mixed-shell model that reflects g-modes away from the Sun's center is developed further by calibrating its parameters and evaluating a mixing mechanism: buoyancy. The shell roughly doubles g-mode oscillation periods and would explain why there is no definitive detection of their periods. But the shell has only minor effects on most p-modes. The model provides a mechanism for causing short-term fluctuations in neutrino flux and makes plausible the correlations between this flux and solar activity levels. Relations are derived for a shell heated asymmetrically by transient increases in nuclear burning in small 'hot spots'. The size of these spots and the timing of a heating event are governed by sets(l) of standing asymptotic g-modes, coupled by a maximal principle that greatly enhances their excitation and concentrates power toward the equator, assisting the detection of higher-l sets. Signals from all sets, except one, in the range 2 {<=} l {<=} 8 are identified by difference periods between consecutive radial states using the method of Garcia et al. and reinterpreting their latest spectrum. This confirms two detections of sets in a similar range of l by their rotation rates. The mean radius of shell mixing is r{sub m} = 0.16 R{sub sun}, which improves an earlier independent estimate of 0.18 by the author. The shell may cause the unexplained dip in measured sound speed at its location. Another sound speed error, centered near 0.67 R{sub sun}, and reversing flows in the same place with a period originally near 1.3 yr suggest that the g-modes are depositing there about 3% of the solar luminosity. That implies the shell at r{sub m} is receiving a similar magnitude of power, which would be enough energy to mix the corresponding shell in a standard solar model in <<10{sup 7} yr.

  16. High energy-resolution measurement of the 82Se(3He,t )82Br reaction for double-β decay and for solar neutrinos

    NASA Astrophysics Data System (ADS)

    Frekers, D.; Alanssari, M.; Adachi, T.; Cleveland, B. T.; Dozono, M.; Ejiri, H.; Elliott, S. R.; Fujita, H.; Fujita, Y.; Fujiwara, M.; Hatanaka, K.; Holl, M.; Ishikawa, D.; Matsubara, H.; Okamura, H.; Puppe, P.; Suda, K.; Tamii, A.; Thies, J.; Yoshida, H. P.

    2016-07-01

    A high-resolution (3He,t ) charge-exchange experiment at an incident energy of 420 MeV has been performed on the double beta (β β ) decay nucleus 82Se. A detailed Gamow-Teller (GT-) strength distribution in 82Br has been extracted, which provides information to the β β -decay nuclear matrix elements. Three strong and isolated transitions, which are to the 75, 1484 and the 2087 keV states in 82Br, are found to dominate the low-excitation region below ≈2.1 MeV. Above 2.1 MeV a sudden onset of a strong GT fragmentation is observed. The degree of fragmentation resembles a situation found in the neighboring A =76 system 76Ge, whereas the observed concentration of strength in the three low-lying states is reminiscent of the heavier neighbors 96Zr and 100Mo. The strong GT transition to the 75 keV ( 1+) state makes 82Se interesting for solar neutrino detection. The 82Se(νe,e-)82Br solar neutrino capture rate in a nonoscillation scenario is therefore evaluated to 668 ±12 (stat)±60 (sys) SNU, and some of the advantages of using selenium for solar neutrino studies are discussed.

  17. Neutrino clouds and dark matter

    SciTech Connect

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

    1996-12-31

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

  18. Democratic Neutrino Paradigm

    NASA Astrophysics Data System (ADS)

    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.

  19. FALSE-ALARM PROBABILITY IN RELATION TO OVERSAMPLED POWER SPECTRA, WITH APPLICATION TO SUPER-KAMIOKANDE SOLAR NEUTRINO DATA

    SciTech Connect

    Sturrock, Peter A.; Scargle, Jeffrey D.

    2010-07-20

    The term 'false-alarm probability' denotes the probability that at least one out of M independent power values in a prescribed search band of a power spectrum computed from a white-noise time series is expected to be as large as or larger than a given value. The usual formula is based on the assumption that powers are distributed exponentially, as one expects for power measurements of normally distributed random noise. However, in practice, one typically examines peaks in an oversampled power spectrum. It is therefore more appropriate to compare the strength of a particular peak with the distribution of peaks in oversampled power spectra derived from normally distributed random noise. We show that this leads to a formula for the false-alarm probability that is rather more conservative than the familiar formula. We also show how to combine these results with a Bayesian method for estimating the probability of the null hypothesis (that there is no oscillation in the time series), and we discuss as an example the application of these procedures to Super-Kamiokande solar neutrino data.

  20. The nylon scintillator containment vessels for the Borexino solar neutrino experiment

    NASA Astrophysics Data System (ADS)

    Cadonati, L.; Calaprice, F.; Galbiati, C.; Pocar, A.; Shutt, T.

    2014-06-01

    The neutrino event rate in the Borexino scintillator is very low ( 0.5 events per day per ton) and concentrated in an energy region well below the 2.6 MeV threshold of natural radioactivity. The intrinsic radioactive contaminants in the photomultipliers (PMTs), in the Stainless Steel Sphere, and in other detector components, play special requirements on the system required to contain the scintillator. The liquid scintillator must be shielded from the Stainless Steel Sphere and from the PMTs by a thick barrier of buffer fluid. The fluid barrier, in addition, needs to be segmented in order to contain migration of radon and daughters emanated by the Stainless Steel Sphere and by the PMTs. These requirements were met by designing and building two spherical vessel made of thin nylon film. The inner vessel contains the scintillator, separating it from the surrounding buffer. The buffer region itself is divided into two concentric shells by the second, outer nylon vessel. In addition, the two nylon vessels must satisfy stringent requirements for radioactivity and for mechanical, optical and chemical properties. This paper describes the requirements of the the nylon vessels for the Borexino experiment and offers a brief overview of the construction methods adopted to meet those requirements.

  1. Neutrino masses: from fantasy to facts

    NASA Astrophysics Data System (ADS)

    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.

  2. Planck-scale physics and neutrino masses

    NASA Astrophysics Data System (ADS)

    Akhmedov, Evgenii Kh.; Berezhiani, Zurab G.; Senjanovic, Goran

    1992-11-01

    We discuss gravitationally induced masses and mass splittings of Majorana, Zeldovich-Konopinski-Mahmoud, and Dirac neutrinos. Among other implications, these effects can provide a solution of the solar neutrino puzzle. In particular, we show how this may work in the 17 keV neutrino picture.

  3. Neutrino Physics

    DOE R&D Accomplishments Database

    Lederman, L. M.

    1963-01-09

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

  4. Neutrino physics

    SciTech Connect

    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.

  5. Evidence for neutrino mass: A decade of discovery

    SciTech Connect

    Heeger, Karsten M.

    2004-12-08

    Neutrino mass and mixing are amongst the major discoveries of recent years. From the observation of flavor change in solar and atmospheric neutrino experiments to the measurements of neutrino mixing with terrestrial neutrinos, recent experiments have provided consistent and compelling evidence for the mixing of massive neutrinos. The discoveries at Super-Kamiokande, SNO, and KamLAND have solved the long-standing solar neutrino problem and demand that we make the first significant revision of the Standard Model in decades. Searches for neutrinoless double-beta decay probe the particle nature of neutrinos and continue to place limits on the effective mass of the neutrino. Possible signs of neutrinoless double-beta decay will stimulate neutrino mass searches in the next decade and beyond. I review the recent discoveries in neutrino physics and the current evidence for massive neutrinos.

  6. Neutrino oscillations and the seesaw origin of neutrino mass

    NASA Astrophysics Data System (ADS)

    Miranda, O. G.; Valle, J. W. F.

    2016-07-01

    The historical discovery of neutrino oscillations using solar and atmospheric neutrinos, and subsequent accelerator and reactor studies, has brought neutrino physics to the precision era. We note that CP effects in oscillation phenomena could be difficult to extract in the presence of unitarity violation. As a result upcoming dedicated leptonic CP violation studies should take into account the non-unitarity of the lepton mixing matrix. Restricting non-unitarity will shed light on the seesaw scale, and thereby guide us towards the new physics responsible for neutrino mass generation.

  7. EXPLOSIVE NUCLEOSYNTHESIS IN THE NEUTRINO-DRIVEN ASPHERICAL SUPERNOVA EXPLOSION OF A NON-ROTATING 15 M{sub sun} STAR WITH SOLAR METALLICITY

    SciTech Connect

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

    2011-09-01

    We investigate explosive nucleosynthesis in a non-rotating 15 M{sub sun} star with solar metallicity that explodes by a neutrino-heating supernova (SN) mechanism aided by both standing accretion shock instability (SASI) and convection. To trigger explosions in our two-dimensional hydrodynamic simulations, we approximate the neutrino transport with a simple light-bulb scheme and systematically change the neutrino fluxes emitted from the protoneutron star. By a post-processing calculation, we evaluate abundances and masses of the SN ejecta for nuclei with a mass number {<=}70, employing a large nuclear reaction network. Aspherical abundance distributions, which are observed in nearby core-collapse SN remnants, are obtained for the non-rotating spherically symmetric progenitor, due to the growth of a low-mode SASI. The abundance pattern of the SN ejecta is similar to that of the solar system for models whose masses range between (0.4-0.5) M{sub sun} of the ejecta from the inner region ({<=}10, 000 km) of the precollapse core. For the models, the explosion energies and the {sup 56}Ni masses are {approx_equal} 10{sup 51}erg and (0.05-0.06) M{sub sun}, respectively; their estimated baryonic masses of the neutron star are comparable to the ones observed in neutron-star binaries. These findings may have little uncertainty because most of the ejecta is composed of matter that is heated via the shock wave and has relatively definite abundances. The abundance ratios for Ne, Mg, Si, and Fe observed in the Cygnus loop are reproduced well with the SN ejecta from an inner region of the 15 M{sub sun} progenitor.

  8. Neutrino Factories

    SciTech Connect

    Geer, Steve; /Fermilab

    2010-01-01

    Over the last decade there has been significant progress in developing the concepts and technologies needed to produce, capture and accelerate O(10{sup 21}) muons/year. This prepares the way for a Neutrino Factory (NF) in which high energy muons decay within the straight sections of a storage ring to produce a beam of neutrinos and anti-neutrinos. The NF concept was proposed in 1997 at a time when the discovery that the three known types of neutrino ({nu}{sub e}, {nu}{sub {mu}}, {nu}{sub {tau}}) can change their flavor as they propagate through space (neutrino oscillations) was providing a first glimpse of physics beyond the Standard Model. This development prepares the way for a new type of neutrino source: a Neutrino Factory. This article reviews the motivation, design and R&D for a Neutrino Factory.

  9. Neutrino physics

    SciTech Connect

    Kayser, Boris; /Fermilab

    2005-06-01

    Thanks to compelling evidence that neutrinos can change flavor, we now know that they have nonzero masses, and that leptons mix. In these lectures, we explain the physics of neutrino flavor change, both in vacuum and in matter. Then, we describe what the flavor-change data have taught us about neutrinos. Finally, we consider some of the questions raised by the discovery of neutrino mass, explaining why these questions are so interesting, and how they might be answered experimentally.

  10. Neutrino Factories

    NASA Astrophysics Data System (ADS)

    Geer, Steve

    2010-06-01

    Over the last decade there has been significant progress in developing the concepts and technologies needed to produce, capture and accelerate O(1021) muons/year. This development prepares the way for a new type of neutrino source : a Neutrino Factory. This article reviews the motivation, design and R&D for a Neutrino Factory.

  11. Neutrino oscillations refitted

    NASA Astrophysics Data System (ADS)

    Forero, D. V.; Tórtola, M.; Valle, J. W. F.

    2014-11-01

    Here, we update our previous global fit of neutrino oscillations by including the recent results that have appeared since the Neutrino 2012 conference. These include the measurements of reactor antineutrino 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 θ23 is consistent with maximal mixing. We also determine the impact of the new data upon all the other neutrino oscillation parameters with an emphasis on the increasing sensitivity to the C P phase, thanks to the interplay between accelerator and reactor data. In the Appendix, we present the updated results obtained after the inclusion of new reactor data presented at the Neutrino 2014 conference. We discuss their impact on the global neutrino analysis.

  12. Sterile Neutrinos

    NASA Astrophysics Data System (ADS)

    Palazzo, Antonio

    2016-05-01

    Several anomalies recorded in short-baseline neutrino experiments suggest the possibility that the standard 3-flavor framework may be incomplete and point towards a manifestation of new physics. Light sterile neutrinos provide a credible solution to these puzzling results. Here, we present a concise review of the status of the neutrino oscillations within the 3+1 scheme, the minimal extension of the standard 3-flavor framework endowed with one sterile neutrino species. We emphasize the potential role of LBL experiments in the searches of CP violation related to sterile neutrinos and their complementarity with the SBL experiments.

  13. Supernova neutrinos and explosive nucleosynthesis

    SciTech Connect

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

    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.

  14. Supernova neutrinos and explosive nucleosynthesis

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

    Core-collapse supernovae eject huge amount of flux of energetic neutrinos. We studied the explosive nucleosyn-thesis in supernovae and found that several isotopes 7Li, 11B, 92Nb, 138La and 180Ta as well as r-process nuclei are affected by the neutrino interactions. The abundance of these isotopes therefore depends strongly on the neutrino flavor oscillation due to the Mikheyev-Smirnov-Wolfenstein (MSW) effect. We discuss first how to determine the neutrino temperatures in order to explain the observed solar system abundances of these isotopes, combined with Galactic chemical evolution of the light nuclei and the heavy r-process elements. We then study the effects of neutrino oscillation on their abundances, and propose a novel method to determine the still unknown neutrino oscillation parameters, mass hierarchy and θ13, simultaneously. There is recent evidence that SiC X grains from the Murchison meteorite may contain supernova-produced light elements 11B and 7Li encapsulated in the presolar grains. Combining the recent experimental constraints on θ13, we show that our method sug-gests at a marginal preference for an inverted neutrino mass hierarchy. Finally, we discuss supernova relic neutrinos that may indicate the softness of the equation of state (EoS) of nuclear matter as well as adiabatic conditions of the neutrino oscillation.

  15. One 17-keV Majorana neutrino?

    NASA Astrophysics Data System (ADS)

    Carlson, Eric; Randall, Lisa

    1991-06-01

    A model is presented accommodating a 17-keV neutrino with 1 percent mixing with the electron neutrino and bounds on the electron-neutrino mass and neutrinoless double-beta decay. However, in contrast to previous models, there is only a single state with mass 17 keV. This model is consistent with cosmological and supernova-cooling constraints, and incorporates the Mikheyev-Smirnov-Wolfenstein explanation of the low solar-neutrino counts. Possible signatures of this model include an excess of muon neutrinos from a supernova explosion, spread over a period of 10-1000 sec, and a Higgs-boson decay signature of leptons plus missing energy.

  16. Neutrino mass and mixing: Summary of the neutrino sessions

    SciTech Connect

    Bowles, T.J.

    1993-01-01

    A great deal of experimental and theoretical effort is underway to use neutrinos as a probe for Physics Beyond the Standard Model. Most of these efforts center on the questions of the possible existence of non zero neutrino mass and mixing. Sessions at the Moriond conferences have dealt with these questions at most of the meetings during the last several years and this year was no exception. Presentations covering most of the current and planned research in this field were presented and discussed. Although there is, at present, no definitive evidence for a non zero neutrino mass and mixing, several unresolved problems (in particular solar neutrinos) do seem to be indicating the likely existence of new neutrino properties. It is likely that before the end of this decade, efforts now being initiated will be able to determine whether or not the hints we are now seeing are really due to new physics.

  17. Low energy neutrinos in Super-Kamiokande

    NASA Astrophysics Data System (ADS)

    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.

  18. Neutrino factory

    SciTech Connect

    Bogomilov, M.; Matev, R.; 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.; Makhov, N.; Neuffer, D.; Popovic, M.; Strait, J.; Striganov, S.; Morfín, J. G.; Wands, R.; Snopok, P.; Bagacz, 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.

    2014-12-08

    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 nu. Design Study consortium. EURO nu coordinated the European contributions to the International Design Study for the Neutrino Factory (the IDS-NF) collaboration. The EURO nu baseline accelerator facility will provide 10(21) muon decays per year from 12.6 GeV stored muon beams serving a single neutrino detector situated at a source-detector distance of between 1 500 km and 2 500 km. A suite of near detectors will allow definitive neutrino-scattering experiments to be performed.

  19. Neutrino factory

    DOE PAGESBeta

    Bogomilov, M.; Matev, R.; Tsenov, R.; Dracos, M.; Bonesini, M.; Palladino, V.; Tortora, L.; Mori, Y.; Planche, T.; Lagrange, J. B.; et al

    2014-12-08

    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 ofmore » 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 nu. Design Study consortium. EURO nu coordinated the European contributions to the International Design Study for the Neutrino Factory (the IDS-NF) collaboration. The EURO nu baseline accelerator facility will provide 10(21) muon decays per year from 12.6 GeV stored muon beams serving a single neutrino detector situated at a source-detector distance of between 1 500 km and 2 500 km. A suite of near detectors will allow definitive neutrino-scattering experiments to be performed.« less

  20. GUT implications from neutrino mass

    SciTech Connect

    Carl H. Albright

    2001-06-26

    An overview is given of the experimental neutrino mixing results and types of neutrino models proposed, with special attention to the general features of various GUT models involving intra-family symmetries and horizontal flavor symmetries. Many of the features are then illustrated by a specific SO (10) SUSY GUT model formulated by S.M. Barr and the author which can explain all four types of solar neutrino mixing solutions by various choices of the right-handed Majorana mass matrix. The quantitative nature of the model's large mixing angle solution is used to compare the reaches of a neutrino super beam and a neutrino factory for determining the small U{sub e3} mixing matrix element.

  1. Neutrino Oscillations With Two Sterile Neutrinos

    NASA Astrophysics Data System (ADS)

    Kisslinger, Leonard S.

    2016-06-01

    This work estimates the probability of μ to e neutrino oscillation with two sterile neutrinos using a 5×5 U-matrix, an extension of the previous estimate with one sterile neutrino and a 4×4 U-matrix. The sterile neutrino-active neutrino mass differences and the mixing angles of the two sterile neutrinos with the three active neutrinos are taken from recent publications, and the oscillation probability for one sterile neutrino is compared to the previous estimate.

  2. Atmospheric neutrinos

    NASA Astrophysics Data System (ADS)

    Gaisser, Thomas K.

    2016-05-01

    In view of the observation by IceCube of high-energy astrophysical neutrinos, it is important to quantify the uncertainty in the background of atmospheric neutrinos. There are two sources of uncertainty, the imperfect knowledge of the spectrum and composition of the primary cosmic rays that produce the neutrinos and the limited understanding of hadron production, including charm, at high energy. This paper is an overview of both aspects.

  3. Neutrino mass models

    NASA Astrophysics Data System (ADS)

    King, S. F.

    2004-02-01

    This is a review article about neutrino mass models, particularly see-saw models involving three active neutrinos that are capable of describing both the atmospheric neutrino oscillation data and the large mixing angle (LMA) MSW solar solution, which is now uniquely specified by recent data. We briefly review the current experimental status, show how to parametrize 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 with an early proposal for obtaining LMAs. 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 tabulate some possible models before focusing on two particular examples based on SO(10) grand unification and either U(1) or SU(3) family symmetry as specific examples. This review contains extensive appendices that include techniques for analytically diagonalizing different types of mass matrices involving two LMAs and one small mixing angle, to leading order in the small mixing angle.

  4. Three dimensional calculation of flux of low energy atmospheric neutrinos

    NASA Technical Reports Server (NTRS)

    Lee, H.; Bludman, S. A.

    1985-01-01

    Results of three-dimensional Monte Carlo calculation of low energy flux of atmospheric neutrinos are presented and compared with earlier one-dimensional calculations 1,2 valid at higher neutrino energies. These low energy neutrinos are the atmospheric background in searching for neutrinos from astrophysical sources. Primary cosmic rays produce the neutrino flux peaking at near E sub=40 MeV and neutrino intensity peaking near E sub v=100 MeV. Because such neutrinos typically deviate by 20 approximately 30 from the primary cosmic ray direction, three-dimensional effects are important for the search of atmospheric neutrinos. Nevertheless, the background of these atmospheric neutrinos is negligible for the detection of solar and supernova neutrinos.

  5. Atmospheric neutrinos and discovery of neutrino oscillations

    PubMed Central

    Kajita, Takaaki

    2010-01-01

    Neutrino oscillation was discovered through studies of neutrinos produced by cosmic-ray interactions in the atmosphere. These neutrinos are called atmospheric neutrinos. They are produced as decay products in hadronic showers resulting from collisions of cosmic rays with nuclei in the atmosphere. Electron-neutrinos and muon-neutrinos are produced mainly by the decay chain of charged pions to muons to electrons. Atmospheric neutrino experiments observed zenith-angle and energy dependent deficit of muon-neutrino events. Neutrino oscillations between muon-neutrinos and tau-neutrinos explain these data well. Neutrino oscillations imply that neutrinos have small but non-zero masses. The small neutrino masses have profound implications to our understanding of elementary particle physics and the Universe. This article discusses the experimental discovery of neutrino oscillations. PMID:20431258

  6. An ''archaeological'' quest for galactic supernova neutrinos

    SciTech Connect

    Lazauskas, Rimantas; Volpe, Cristina E-mail: Cecilia.Lunardini@asu.edu

    2009-04-15

    We explore the possibility to observe the effects of electron neutrinos from past galactic supernovae, through a geochemical measurement of the amount of Technetium 97 produced by neutrino-induced reactions in a Molybdenum ore. The calculations we present take into account the recent advances in our knowledge of neutrino interactions, of neutrino oscillations inside a supernova, of the solar neutrino flux at Earth and of possible failed supernovae. The predicted Technetium 97 abundance is of the order of 10{sup 7} atoms per 10 kilotons of ore, which is close to the current geochemical experimental sensitivity. Of this, {approx} 10-20% is from supernovae. Considering the comparable size of uncertainties, more precision in the modeling of neutrino fluxes as well as of neutrino cross sections is required for a meaningful measurement.

  7. KATRIN: Measuring the Mass Scale of Neutrinos

    NASA Astrophysics Data System (ADS)

    Oblath, Noah; Katrin Collaboration

    2011-10-01

    Over the past decade, experiments studying neutrinos from atmospheric, solar, and reactor sources have shown conclusively that neutrinos change flavor and, as a consequence, have a small but finite mass. However, the scale of neutrino masses remains an open question that is of great importance for many areas of physics. The most direct method to measure the neutrino mass scale is still via beta decay. The talk will focus primarily on the status of the KArlsruhe TRItium Neutrino experiment (KATRIN), currently under construction. KATRIN combines an ultra-luminous molecular windowless gaseous tritium source with a high-resolution integrating spectrometer to gain sensitivity to the absolute mass scale of neutrinos. The projected sensitivity of the experiment on the neutrino mass is 0.2 eV at 90% C.L. In this talk I will discuss the status of the KATRIN experiment.

  8. Experimental Measurement of Low Energy Neutrino Interactions

    SciTech Connect

    Scholberg, Kate

    2011-11-23

    Neutrino interactions in the few to few tens of MeV range are of importance for several physics topics, including solar, supernova and reactor neutrinos, as well as future proposed oscillation and Standard Model test experiments. Although interaction cross-sections for some simple targets are well understood, very little experimental data exist for interactions with nuclei. This talk will discuss the motivation for measuring low energy neutrino interactions, the state of knowledge, and possible future strategies.

  9. Neutrino Masses and Mixings in SO(10)

    NASA Astrophysics Data System (ADS)

    Abud, M.; Buccella, F.; Tramontano, F.; Falcone, D.; Ricciardi, G.

    Assuming a Zee-like matrix for the right-handed neutrino Majorana masses in the seesaw mechanism, one gets maximal mixing for vacuum solar oscillations, a very small value for Ue3 and an approximate degeneracy for the two lower neutrino masses. The scale of right-handed neutrino Majorana masses is in good agreement with the value expected in an SO(10) model with Pati-Salam SU(4)×SU(2)×SU(2) intermediate symmetry.

  10. Nonstandard neutrino-neutrino refractive effects in dense neutrino gases

    SciTech Connect

    Blennow, Mattias; Mirizzi, Alessandro; Serpico, Pasquale D.; /CERN /Fermilab

    2008-10-01

    We investigate the effects of nonstandard four-fermion neutrino-neutrino interactions on the flavor evolution of dense neutrino gases. We find that in the regions where the neutrino-neutrino refractive index leads to collective flavor oscillations, the presence of new neutrino interactions can produce flavor equilibration in both normal and inverted neutrino mass hierarchy. In realistic supernova environments, these effects are significant if the nonstandard neutrino-neutrino interaction strength is comparable to the one expected in the standard case, dominating the ordinary matter potential. However, very small nonstandard neutrino-neutrino couplings are enough to trigger the usual collective neutrino flavor transformations in the inverted neutrino mass hierarchy, even if the mixing angle vanishes exactly.