A search has been performed for neutrinos from two sources, the hep reaction in the solar pp fusion chain and the upsilon e component of the diffuse supernova neutrino background (DSNB), using the full dataset of the Sudbury Neutrino Observatory with a total exposure of 2.47 kton-years after fiducialization. The hep search is performed using both a single-bin counting analysis and a likelihood fit. We find a best-fit flux that is compatible with solar model predictions while remaining consistent with zero flux, and set a onesided upper limit of Phi(hep) < 30 x 10(3) cm(-2) s(-1) [90% credible interval (CI)]. No events are observed in the DSNB search region, and we set an improved upper bound on the nu(e) component of the DSNB flux of Phi(DSNB)(nu e) < 19 cm(-2) s(-1) (90% CI) in the energy range 22.9 < E-nu < 36.9 MeV.

Neutrons produced in nuclear interactions initiated by cosmic-ray muons present an irreducible background to many rare-event searches, even in detectors located deep underground. Models for the production of these neutrons have been tested against previous experimental data, but the extrapolation to deeper sites is not well understood. Here we report results from an analysis of cosmogenically produced neutrons at the Sudbury Neutrino Observatory. A specific set of observables are presented, which can be used to benchmark the validity of GEANT4 physics models. In addition, the cosmogenic neutron yield, in units of 10(-4) cm(2)/(g.mu), is measured to be 7.28 +/- 0.09(stat)(-1.12)(+1.59)(syst) in pure heavy water and 7.30 +/- 0.07(stat)(-1.02)(+1.40)(syst) in NaCl-loaded heavy water. These results provide unique insights into this potential background source for experiments at SNOLAB.

Neutron production in giga electron volt-scale neutrino interactions is a poorly studied process. We have measured the neutron multiplicities in atmospheric neutrino interactions in the Sudbury Neutrino Observatory experiment and compared them to the prediction of a Monte Carlo simulation using GENIE and a minimally modified version of GEANT4. We analyzed 837 days of exposure corresponding to Phase I, using pure heavy water, and Phase II, using a mixture of Cl in heavy water. Neutrons produced in atmospheric neutrino interactions were identified with an efficiency of 15.3% and 44.3%, for Phases I and II respectively. The neutron production is measured as a function of the visible energy of the neutrino interaction and, for charged current quasielastic interaction candidates, also as a function of the neutrino energy. This study is also performed by classifying the complete sample into two pairs of event categories: charged current quasielastic and non charged current quasielastic, and nu(mu) and nu(e). Results show good overall agreement between data and Monte Carlo for both phases, with some small tension with a statistical significance below 2 sigma for some intermediate energies.

The long baseline between Earth and the Sun makes solar neutrinos an excellent test beam for exploring possible neutrino decay. The signature of such decaywould be an energy-dependent distortion of the traditional survival probability which can be fit for using well-developed and high-precision analysis methods. Here a model including neutrino decay is fit to all three phases of B-8 solar neutrino data taken by the SudburyNeutrino Observatory (SNO). This fit constrains the lifetime of neutrino mass state nu(2) to be > 8.08 x 10(-5) s/eV at 90% confidence. An analysis combining this SNO result with those from other solar neutrino experiments results in a combined limit for the lifetime of mass state nu(2) of > 1.92 x 10(-3) s/eV at 90% confidence.

Experimental tests of Lorentz symmetry in systems of all types are critical for ensuring that the basic assumptions of physics are well founded. Data from all phases of the Sudbury Neutrino Observatory, a kiloton-scale heavy water Cherenkov detector, are analyzed for possible violations of Lorentz symmetry in the neutrino sector. Such violations would appear as one of eight possible signal types in the detector: six seasonal variations in the solar electron neutrino survival probability differing in energy and time dependence and two shape changes to the oscillated solar neutrino energy spectrum. No evidence for such signals is observed, and limits on the size of such effects are established in the framework of the standard model extension, including 38 limits on previously unconstrained operators and improved limits on 16 additional operators. This makes limits on all minimal, Dirac-type Lorentz violating operators in the neutrino sector available for the first time.

Tests on B - L symmetry breaking models are important probes to search for new physics. One proposed model with Delta(B - L) = 2 involves the oscillations of a neutron to an antineutron. In this paper, a new limit on this process is derived for the data acquired from all three operational phases of the Sudbury Neutrino Observatory experiment. The search concentrated on oscillations occurring within the deuteron, and 23 events were observed against a background expectation of 30.5 events. These translated to a lower limit on the nuclear lifetime of 1.48 x 1031 yr at 90% C. L. when no restriction was placed on the signal likelihood space (unbounded). Alternatively, a lower limit on the nuclear lifetime was found to be 1.18 x 10(31) yr at 90% C. L. when the signal was forced into a positive likelihood space (bounded). Values for the free oscillation time derived from various models are also provided in this article. This is the first search for neutron-antineutron oscillation with the deuteron as a target.

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

We report results from a combined analysis of solar neutrino data from all phases of the Sudbury Neutrino Observatory. By exploiting particle identification information obtained from the proportional counters installed during the third phase, this analysis improved background rejection in that phase of the experiment. The combined analysis resulted in a total flux of active neutrino flavors from 8B decays in the Sun of (5.25 \pm 0.16(stat.)+0.11-0.13(syst.))\times10^6 cm^{-2}s^{-1}. A two-flavor neutrino oscillation analysis yielded \Deltam^2_{21} = (5.6^{+1.9}_{-1.4})\times10^{-5} eV^2 and tan^2{\theta}_{12}= 0.427^{+0.033}_{-0.029}. A three-flavor neutrino oscillation analysis combining this result with results of all other solar neutrino experiments and the KamLAND experiment yielded \Deltam^2_{21} = (7.41^{+0.21}_{-0.19})\times10^{-5} eV^2, tan^2{\theta}_{12} = 0.446^{+0.030}_{-0.029}, and sin^2{\theta}_{13} = (2.5^{+1.8}_{-1.5})\times10^{-2}. This implied an upper bound of sin^2{\theta}_{13} < 0.053 at the 95% confidence level (C.L.).

Results are reported from a search for low-multiplicity neutrino bursts in the Sudbury Neutrino Observatory (SNO). Such bursts could indicate detection of a nearby core-collapse supernova explosion. The data were taken from Phase I (November 1999 - May 2001), when the detector was filled with heavy water, and Phase II (July 2001 - August 2003), when NaCl was added to the target. The search was a blind analysis in which the potential backgrounds were estimated and analysis cuts were developed to eliminate such backgrounds with 90% confidence before the data were examined. The search maintained a greater than 50% detection probability for standard supernovae occurring at a distance of up to 60 kpc for Phase I and up to 70 kpc for Phase II. No low-multiplicity bursts were observed during the data-taking period.

S.N. Ahmed, 10 A.E. Anthony,14 E.W. Beier, 9 A. Bellerive,3 S.D. Biller,8 J. Boger, 2 M.G. Boulay,7 M.G. Bowler,8 T.J. Bowles, 7 S.J. Brice, 7 T.V. Bullard,13 Y.D. Chan, 6 M. Chen,10 X. Chen,6 B.T. Cleveland, 8 G.A. Cox,13 X. Dai,3, 8 F. Dalnoki-Veress, 3 P.J. Doe, 13 R.S. Dosanjh, 3 G. Doucas, 8 M.R. Dragowsky, 7 C.A. Duba, 13 F.A. Duncan, 10 M. Dunford,9 J.A. Dunmore, 8 E.D. Earle, 10 S.R. Elliott,7 H.C. Evans, 10 G.T. Ewan, 10 J. Farine, 5,3 H. Fergani, 8 F. Fleurot, 5 J.A. Formaggio, 13

We have performed three searches for high-frequency signals in the solar neutrino flux measured by the Sudbury Neutrino Observatory (SNO), motivated by the possibility that solar g-mode oscillations could affect the production or propagation of solar B neutrinos. The first search looked for any significant peak in the frequency range 1/day to 144/day, with a sensitivity to sinusoidal signals with amplitudes of 12% or greater. The second search focused on regions in which g-mode signals have been claimed by experiments aboard the SoHO satellite, and was sensitive to signals with amplitudes of 10% or greater. The third search looked for extra power across the entire frequency band. No statistically significant signal was detected in any of the three searches.

Results are reported from a joint analysis of Phase I and Phase II data from the Sudbury Neutrino Observatory. The effective electron kinetic energy threshold used is Teff=3.5 MeV, the lowest analysis threshold yet achieved with water Cherenkov detector data. In units of 106 cm-2 s-1, the total flux of active-flavor neutrinos from 8B decay in the Sun measured using the neutral current (NC) reaction of neutrinos on deuterons, with no constraint on the 8B neutrino energy spectrum, is found to be FNC=5.140-0.158+0.160(stat)-0.117+0.132(syst). These uncertainties are more than a factor of 2 smaller than previously published results. Also presented are the spectra of recoil electrons from the charged current reaction of neutrinos on deuterons and the elastic scattering of electrons. A fit to the Sudbury Neutrino Observatory data in which the free parameters directly describe the total 8B neutrino flux and the energy-dependent e survival probability provides a measure of the total 8B neutrino flux F8B=5.046-0.152+0.159(stat)-0.123+0.107(syst). Combining these new results with results of all other solar experiments and the KamLAND reactor experiment yields best-fit values of the mixing parameters of 12=34.06-0.84+1.16 degrees and m212=7.59-0.21+0.2010-5 eV2. The global value of 8B is extracted to a precision of -2.95+2.38%. In a three-flavor analysis the best fit value of sin213 is 2.00-1.63+2.0910-2. This implies an upper bound of sin213<0.057 (95% C.L.).

The effects of aqueous extract of ximenia Americana stem bark on liver and kidney of albino rats was investigated. Different doses of the crude extract were administered to rats for 30 consecutive days. The levels of serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) of treated animals significantly (p significant (p<0.05) decrease compared to the control group. There was no significant difference in the serum levels of urea and creatinine of the treated animals compared to the control. The data obtained is suggestive of liver damage and unaffected kidney.

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

A search has been made for neutrinos from the hep reaction in the Sun and from the diffuse supernova neutrino background (DSNB) using data collected during the first operational phase of the Sudbury Neutrino Observatory, with an exposure of 0.65 ktons yr. For the hep neutrino search, two events are observed in the effective electron energy range of 14: 3 MeV < T-eff < 20 MeV, where 3.1 background events are expected. After accounting for neutrino oscillations, an upper limit of 2.3 x 10(4) cm(-2) s(-1) at the 90% confidence level is inferred on the integral total flux of hep neutrinos. For DSNB neutrinos, no events are observed in the effective electron energy range of 21 MeV < T-eff < 35 MeV, and, consequently, an upper limit on the v(e) component of the DSNB flux in the neutrino energy range of 22.9 MeV < E-v < 36.9 MeV of 70 cm(-2) s(-1) is inferred at the 90% confidence level. This is an improvement by a factor of 6.5 on the previous best upper limit on the hep neutrino flux and by 2 orders of magnitude on the previous upper limit on the v(e) component of the DSNB flux.

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

Author(s): Aharmim, B.; Ahmed, S.N.; Anthony, A.E.; Beier, E.W.; Bellerive, A.; Bergevin, M.; Biller, S.D.; Boger, J.; Boulay, M.G.; Bowler, M.G.; Bullard, T.V.; Chan, Y.D.; Chen, M.; Chen, X.; Cleveland, B.T.; Cox, G.A.; Currat, C.A.; Dai, X.; Dalnoki-Veress, F.; Deng, H.; Doe, P.J.; Dosanjh, R.S.; Doucas, G.; Duba, C.A.; Duncan, F.A.; Dunford, M.; Dunmore, J.A.; Earle, E.D.; Elliott, S.R.; Evans, H.C.; Ewan, G.T.; Farine, J.; Fergani, H.; Fleurot, F.; Formaggio, J.A.; Frame, K.; Frati, W.; Fulsom, B.G.; Gagnon, N.; Graham, K.; Grant, D.R.; Hahn, R.L.; Hall, J.C.; Hallin, A.L.; Hallman, E.D.; Handler, W.B.; Hargrove, C.K.; Harvey, P.J.; Hazama, R.; Heeger, K.M.; Heelan, L.; Heintzelman, W.J.; Heise, J.; Helmer, R.L.; Hemingway, R.J.; Hime, A.; Howard, C.; Howe, M.A.; Huang, M.; Jagam, P.; Jelley, N.A.; Klein, J.R.; Kormos, L.L.; Kos, M.S.; Kruger, A.; Kraus, C.; Krauss, C.B.; Krumins, A.V.; Kutter, T.; Kyba, C.C.M.; Labranche, H.; Lange, R.; Law, J.; Lawson, I.T.; Lesko, K.T.; Leslie, J.R.; Levine, I.; Loach, J.C.; Luoma, S.; MacLellan, R.; Majerus, S.; Mak, H.B.; Maneira, J.; Marino, A.D.; McCauley, N. | Abstract: Results are reported from the complete salt phase of the Sudbury Neutrino Observatory experiment in which NaCl was dissolved in the D_2O target. The addition of salt enhanced the signal from neutron capture, as compared to the pure D_2O 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 106 cm-2 s-1, the total flux of active-flavor neutrinos from 8B decay in the Sun is found to be 4.94+0.21_-0.21(stat)+0.38_-0.34(syst) and the integral flux of electron neutrinos for an undistorted 8B spectrum is 1.68+0.06_-0.06(stat)+0.08_-0.09(syst); the signal from (nu_x,e) elastic scattering is equivalent to an electron-neutrino flux of 2.35+0.22-0.22(stat)+0.15_-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 m2 = (8.0+0.6_-0.4) x 10-5 eV2 and theta = 33.9 +2.4_-2.2 degrees.

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

Data from the Sudbury Neutrino Observatory have been used to constrain the lifetime for nucleon decay to "invisible" modes, such as n-->3nu. The analysis was based on a search for gamma rays from the deexcitation of the residual nucleus that would result from the disappearance of either a proton or neutron from 16O. A limit of tau(inv)>2 x 10(29) yr is obtained at 90% confidence for either neutron- or proton-decay modes. This is about an order of magnitude more stringent than previous constraints on invisible proton-decay modes and 400 times more stringent than similar neutron modes.