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Title: Solar model parameters and direct measurements of solar neutrino fluxes

Abstract

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

Authors:
 [1];  [2];  [3];  [2];  [4];  [5]
  1. Tata Institute of Fundamental Research, Mumbai 400005 (India)
  2. Harish-Chandra Research Institute, Allahabad 211 019 (India)
  3. (United Kingdom)
  4. (Germany)
  5. Scuola Internazionale Superiore di Studi Avanzati and Instituto Nazionale di Fisica Nucleare, I-34014 Trieste (Italy)
Publication Date:
OSTI Identifier:
21020471
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. D, Particles Fields; Journal Volume: 75; Journal Issue: 9; Other Information: DOI: 10.1103/PhysRevD.75.093007; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; BERYLLIUM 7; BORON 8; GLOBAL ANALYSIS; NEUTRINO DETECTION; NEUTRINO REACTIONS; RADIATION FLUX; SOLAR NEUTRINOS; STAR MODELS

Citation Formats

Bandyopadhyay, Abhijit, Choubey, Sandhya, Theoretical Physics, University of Oxford, 1 Keble Road, Oxford OX1 3NP, Goswami, Srubabati, Physik-Department T30d, Technische Universitaet Muenchen, D-85748 Garching, and Petcov, S. T. Solar model parameters and direct measurements of solar neutrino fluxes. United States: N. p., 2007. Web. doi:10.1103/PHYSREVD.75.093007.
Bandyopadhyay, Abhijit, Choubey, Sandhya, Theoretical Physics, University of Oxford, 1 Keble Road, Oxford OX1 3NP, Goswami, Srubabati, Physik-Department T30d, Technische Universitaet Muenchen, D-85748 Garching, & Petcov, S. T. Solar model parameters and direct measurements of solar neutrino fluxes. United States. doi:10.1103/PHYSREVD.75.093007.
Bandyopadhyay, Abhijit, Choubey, Sandhya, Theoretical Physics, University of Oxford, 1 Keble Road, Oxford OX1 3NP, Goswami, Srubabati, Physik-Department T30d, Technische Universitaet Muenchen, D-85748 Garching, and Petcov, S. T. Tue . "Solar model parameters and direct measurements of solar neutrino fluxes". United States. doi:10.1103/PHYSREVD.75.093007.
@article{osti_21020471,
title = {Solar model parameters and direct measurements of solar neutrino fluxes},
author = {Bandyopadhyay, Abhijit and Choubey, Sandhya and Theoretical Physics, University of Oxford, 1 Keble Road, Oxford OX1 3NP and Goswami, Srubabati and Physik-Department T30d, Technische Universitaet Muenchen, D-85748 Garching and Petcov, S. T.},
abstractNote = {We explore a novel possibility of determining the solar model parameters, which serve as input in the calculations of the solar neutrino fluxes, by exploiting the data from direct measurements of the fluxes. More specifically, we use the rather precise value of the {sup 8}B neutrino flux, {phi}{sub B} obtained from the global analysis of the solar neutrino and KamLAND data, to derive constraints on each of the solar model parameters on which {phi}{sub B} depends. We also use more precise values of {sup 7}Be and pp fluxes as can be obtained from future prospective data and discuss whether such measurements can help in reducing the uncertainties of one or more input parameters of the standard solar model.},
doi = {10.1103/PHYSREVD.75.093007},
journal = {Physical Review. D, Particles Fields},
number = 9,
volume = 75,
place = {United States},
year = {Tue May 01 00:00:00 EDT 2007},
month = {Tue May 01 00:00:00 EDT 2007}
}
  • Individual neutrino fluxes are not well determined by the four operating solar neutrino experiments. Assuming neutrino oscillations occur, the {ital pp} electron neutrino flux is uncertain by a factor of 2, the {sup 8}B flux by a factor of 5, and the {sup 7}Be flux by a factor of 45. For matter-enhanced oscillation (MSW) solutions, the range of allowed differences of squared neutrino masses, {Delta}{ital m}{sup 2}, varies between 4{times}10{sup {minus}6} eV{sup 2} and 1{times}10{sup {minus}4} eV{sup 2}, while 4{times}10{sup {minus}3}{le}sin{sup 2}2{theta}{le}1.5{times}10{sup {minus}2} or 0.5{le}sin{sup 2}2{theta}{le}0.9. For vacuum oscillations, {Delta}{ital m}{sup 2} varies between 5{times}10{sup {minus}11} eV{sup 2} and 1{times}10{supmore » {minus}10} eV{sup 2}, while 0.7{le}sin{sup 2}2{theta}{le}1.0. The inferred ranges of neutrino parameters depend only weakly on which standard solar model is used. Calculations of the expected results of future solar neutrino experiments (SuperKamiokande, SNO, BOREXINO, ICARUS, HELLAZ, and HERON) are used to illustrate the extent to which these experiments will restrict the range of the allowed neutrino mixing parameters. For example, the double ratio (observed ratio divided by standard model ratio) of neutral current to charged current event rates to be measured in the SNO experiment varies, at 95{percent} confidence limit, over the range 1.0 (no oscillations into active neutrinos), 3.1{sub {minus}1.3}{sup +1.8} (small mixing angle MSW), 4.4{sub {minus}1.4}{sup +2.0} (large mixing angle MSW), and 5.2{sub {minus}2.9}{sup +5.6} (vacuum oscillations). We present an improved formulation of the {open_quote}{open_quote}luminosity constraint{close_quote}{close_quote} and show that at 95{percent} confidence limit, this constraint establishes the best available limits on the rate of creation of {ital pp} neutrinos in the solar interior and provides the best upper limit to the {sup 7}Be neutrino flux. (Abstract Truncated)« less
  • Results are reported from the complete salt phase of the Sudbury Neutrino Observatory experiment in which NaCl was dissolved in the {sup 2}H{sub 2}O (''D{sub 2}O'') target. The addition of salt enhanced the signal from neutron capture as compared to the pure D{sub 2}O detector. By making a statistical separation of charged-current events from other types based on event-isotropy criteria, the effective electron recoil energy spectrum has been extracted. In units of 10{sup 6}cm{sup -2}s{sup -1}, the total flux of active-flavor neutrinos from {sup 8}B decay in the Sun is found to be 4.94{sub -0.21}{sup +0.21}(stat){sub -0.34}{sup +0.38}(syst) and themore » integral flux of electron neutrinos for an undistorted {sup 8}B spectrum is 1.68{sub -0.06}{sup +0.06}(stat){sub -0.09}{sup +0.08}(syst); the signal from ({nu}{sub x},e) elastic scattering is equivalent to an electron-neutrino flux of 2.35{sub -0.22}{sup +0.22}(stat){sub -0.15}{sup +0.15}(syst). These results are consistent with those expected for neutrino oscillations with the so-called large mixing angle parameters and also with an undistorted spectrum. A search for matter-enhancement effects in the Earth through a possible day-night asymmetry in the charged-current integral rate is consistent with no asymmetry. Including results from other experiments, the best-fit values for two-neutrino mixing parameters are {delta}m{sup 2}=(8.0{sub -0.4}{sup +0.6})x10{sup -5} eV{sup 2} and {theta}=33.9{sub -2.2}{sup +2.4} degrees.« less
  • 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 fromthismore » 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.« less
  • 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 amore » 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.« less
  • The excess of cosmic ray electron and positron fluxes measured by the PAMELA satellite and ATIC balloon experiments may be interpreted as the signals of the dark matter annihilation or decay into leptons. In this paper, we show that the dark matter annihilation/decay which reproduces the electron/positron excess may yield a significant amount of high-energy neutrinos from the Galactic center. In that case, future kilometer-square size experiments may confirm such a scenario, or even the Super-Kamiokande results already put constraints on some dark matter models.