We present a 1353 days measurement of the geo–neutrino flux in Borexino: the signal was found to be 14.3 ± 4.4 events. This result translates into Sgeo = (38.8 ± 12.0) TNU when a Th/U fixed ...chondritic mass ratio of 3.9 is assumed. Furthermore Borexino data are compatible with a mantle geo–neutrino signal of (15.4 ± 12.3) TNU.
We report the direct measurement of the 7Be solar neutrino signal rate performed with the Borexino detector at the Laboratori Nazionali del Gran Sasso. The interaction rate of the 0.862 MeV 7Be ...neutrinos is 49+/-3stat+/-4syst counts/(day.100 ton). The hypothesis of no oscillation for 7Be solar neutrinos is inconsistent with our measurement at the 4sigma C.L. Our result is the first direct measurement of the survival probability for solar nu(e) in the transition region between matter-enhanced and vacuum-driven oscillations. The measurement improves the experimental determination of the flux of 7Be, pp, and CNO solar nu(e), and the limit on the effective neutrino magnetic moment using solar neutrinos.
Low energy neutrinos Ranucci, G; Bellini, G; Benziger, J ...
International Journal of Modern Physics: Conference Series,
2014, Letnik:
31
Journal Article, Conference Proceeding
Recenzirano
Odprti dostop
Low energy neutrino investigation has been one of the most active fields of particle physics research over the past decades, accumulating important and sometimes unexpected achievements. In this work ...some of the most recent impressive successes will be reviewed, as well as the future perspectives of this exciting area of study.
We report the direct measurement of the 7Be solar neutrino signal rate performed with the Borexino detector at the Laboratori Nazionali del Gran Sasso. The interaction rate of the 0.862 MeV 7Be ...neutrinos is 49±3stat±4syst counts/(day·100 ton). The hypothesis of no oscillation for 7Be solar neutrinos is inconsistent with our measurement at the 4σ C.L. Our result is the first direct measurement of the survival probability for solar νe in the transition region between matter-enhanced and vacuum-driven oscillations. The measurement improves the experimental determination of the flux of 7Be, pp, and CNO solar νe, and the limit on the effective neutrino magnetic moment using solar neutrinos.
The Sun is fueled by a series of nuclear reactions that produce the energy that makes it shine. The primary reaction is the fusion of two protons into a deuteron, a positron and a neutrino. These ...neutrinos constitute the vast majority of neutrinos reaching Earth, providing us with key information about what goes on at the core of our star. Several experiments have now confirmed the observation of neutrino oscillations by detecting neutrinos from secondary nuclear processes in the Sun; this is the first direct spectral measurement of the neutrinos from the keystone proton-proton fusion. This observation is a crucial step towards the completion of the spectroscopy of pp-chain neutrinos, as well as further validation of the LMA-MSW model of neutrino oscillations.
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