The study of solar neutrinos and of non-standard neutrino interactions with Borexino

The Borexino liquid scintillator neutrino observatory has a unique capability to perform high-precision solar neutrino observations thanks to its exceptional radiopurity and good energy resolution (5% at 1 MeV). A comprehensive study of the pp-chain neutrinos was presented that includes the direct measurements of Be-7, pp and pep neutrino fluxes with the highest precision ever achieved (down to 2.8% in the Be-7 component), the B-8 with the lowest energy threshold, the best limit on CNO neutrinos and the first Borexino limit on hep neutrinos. These results are important to validate the MSW-LMA oscillation paradigm across the full solar energy range and to exclude possible Non-Standard neutrino Interactions (NSIs). In particular the effects of neutrino-flavor-diagonal Neutral-Current (NC) interactions that modify the v(e)e and v(tau)e couplings while preserving their chiral and flavor structures, have been investigated. At detection, the shape of the electron-recoil spectrum is affected by changes in the v(e)e and V(tau)e couplings, quantified by the parameters epsilon(L/R)(e) and epsilon(L/R)(tau). New bounds to all four parameters were obtained, quite stringent compared to the global ones. In particular, the best constraint to-date on epsilon(L)(e) was achieved. A comprehensive summary of all the recent results on solar neutrinos from Borexino is reported in the present paper.