Recents results from Borexino

par Dr Davide Franco (APC Université Paris VII et CNRS-IN2P3)

lundi 4 juil. 2011, 14:00 → 15:00 Europe/Paris

Auditorium M. Vivargent (LAPP)

http://www.interactions.org/cms/?pid=1030628 and arXiv:1104.2150 Absence of day-night asymmetry of 862 keV Be-7 solar neutrino rate in Borexino and MSW oscillation parameters The Borexino Collaboration We report on a search for the day-night asymmetry of the Be-7 solar neutrino rate measured by Borexino at the Laboratori Nazionali del Gran Sasso (LNGS), Italy. The measured value, Adn=0.001 +- 0.012 (stat) +- 0.007 (syst), shows the absence of a significant asymmetry. This result alone rejects the so-called LOW solution at more than 8.5 sigma. Combined with the other solar neutrino data, it isolates the Large Mixing Angle (LMA) -- MSW solution at DeltaChi2 > 190 without relying on the assumption of CPT symmetry in the neutrino sector. We also show that including the day-night asymmetry, data from Borexino alone restricts the MSW neutrino oscillations to the LMA solution at 90% confidence level.

Slides annecy.pdf