Complete results for five years of GNO solar neutrino observations

Abstract

We report the complete GNO solar neutrino results for the measuring periods GNO III, GNO II, and GNO I. The result for GNO III (last 15 solar runs) is View the MathML source[54.3−9.3+9.9(stat)±2.3(syst)]SNU(1σ)(1σ) or View the MathML source[54.3−9.6+10.2(incl. syst)] SNU (1σ ) with errors combined. The GNO experiment is now terminated after altogether 58 solar exposure runs that were performed between 20 May 1998 and 9 April 2003. The combined result for GNO (I + II + III) is View the MathML source[62.9−5.3+5.5(stat)±2.5(syst)] SNU (1σ ) or View the MathML source[62.9−5.9+6.0] SNU (1σ ) with errors combined in quadrature. Overall, gallium based solar observations at LNGS (first in GALLEX, later in GNO) lasted from 14 May 1991 through 9 April 2003. The joint result from 123 runs in GNO and GALLEX is [69.3±5.5(incl. syst)] SNU[69.3±5.5(incl. syst)] SNU (1σ). The distribution of the individual run results is consistent with the hypothesis of a neutrino flux that is constant in time. Implications from the data in particle- and astrophysics are reiterated

Low-energy-threshold analysis of the Phase I and Phase II data sets of the Sudbury Neutrino Observatory

“…Deployed sources included a diffuse multiwavelength laser that was used to measure PMT timing and optical parameters (the "laserball") [26], a 16 N source that provided a triggered sample of 6.13-MeV γ s [27], and a 8 Li source that delivered tagged βs with an end point near 14 MeV [28]. In addition, 19.8-MeV γ s were provided by a 3 H(p, γ ) 4 He ("pT") source [29] and neutrons by a 252 Cf source. Some of the sources were also deployed on vertical lines in the H 2 O between the AV and PSUP.…”

“…We found that, for the most part, they all had comparable separation power between the single electron (CC and ES) and the neutron (NC) signals. As in our previous Phase II publications [8], we opted to use a linear combination of parameters, β 14 ≡ β 1 + 4β 4 , where:…”

“…Instead of creating a 3D PDF (β 14 , R 3 , cos θ ) for intervals in T eff in the undistorted spectrum, we created 4D PDFs (T eff , β 14 , R 3 , cos θ ) for separate E ν intervals in the undistorted spectrum. There were 9 CC and 9 ES PDFs in each of the 4 day/night phases, with E ν boundaries at 4,6,7,8,9,10,11,12,13, and 15 MeV.…”

“…It is by now well-established that neutrinos are massive and mixed, and that these properties lead to the oscillations observed in measurements of neutrinos produced in the Sun [1][2][3][4][5][6][7][8][9][10], in the atmosphere [11], by accelerators [12,13], and by reactors [14]. The mixing model predicts not only neutrino oscillations in vacuum but also the effects of matter on the oscillation probabilities (the "MSW" effect) [15,16].…”

Interim Design Report

“…Furthermore, energy resolution, background suppression, and systematic uncertainties have been improved. Data from SNO are combined with the global data on solar neutrinos [44][45][46] including updates on Gallium experiments [47,48] as well as results from Borexino [49] on 7 Be neutrinos yielding an improved determination of the atmospheric parameters. The MINOS experiment [50] is searching for ν µ disappearance with a baseline of 735 km.…”