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/100  t, which corresponds to ΦESB8=2.4±0.4±0.1×106  cm−2 s−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.

Measurement of the solar 8B neutrino rate with a liquid scintillator target and 3 MeV energy threshold in the Borexino detector

ORTICA, Fausto;ROMANI, Aldo;
2010

Abstract

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/100  t, which corresponds to ΦESB8=2.4±0.4±0.1×106  cm−2 s−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.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11391/121713
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