Solar neutrinos: the SNO salt phase results and physics of conversion

نویسنده

  • P. C. de Holanda
چکیده

We have performed analysis of the solar neutrino data including results from the SNO salt phase as well as the combined analysis of the solar and the KamLAND results. The best fit values of neutrino parameters are ∆m2 = 7.1 · 10−5 eV2, tan2 θ = 0.40 with the boron flux fB = 1.04. New SNO results strongly disfavor maximal mixing and the h-LMA region (∆m2 > 10−4 eV2) which is accepted now at the 3σ level. We find the 3σ upper bounds: ∆m2 < 1.7 · 10−4 eV2 and tan2 θ < 0.64, and the lower bound ∆m2 > 4.8 · 10−5 eV2. Non-zero 13-mixing does not change these results significantly. The present data determine quantitatively the physical picture of the solar neutrino conversion. At high energies relevant for SNO and SuperKamiokande the deviation of the effective survival probability from the non-oscillatory value is about 10 14%. The oscillation effect contribution to this difference is about 10% and the Earth regeneration about 3 4 %. At low energies (E < 1 MeV) the matter corrections to vacuum oscillation effect are below 5%. The predictions for the forthcoming measurements are given which include the spectral distortion and CC/NC ratio at SNO, the Day-Night asymmetry, the KamLAND spectrum and rate.

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تاریخ انتشار 2003