Physics Letters B
Volume 696, Issue 3, 31 January 2011, Pages 191-196
G. Bellini et al. (Borexino Collaboration) M. Wójcik, G. Zuzel, M. Misiaszek
Download: http://dx.doi.org/10.1016/j.physletb.2010.12.030
Abstract
We report on the search for anti-neutrinos of yet unknown origin with the Borexino detector at the Laboratori Nazionali del Gran Sasso. In particular, a hypothetical anti-neutrino flux from the Sun is investigated. Anti-neutrinos are detected through the neutron inverse β decay reaction in a large liquid organic scintillator target. We set a new upper limit for a hypothetical solar antineutrinos of 760cm-2s-1, obtained assuming an undistorted solar 8B energy spectrum. This corresponds to a limit on the transition probability of solar neutrinos to anti-neutrinos of 1.3×10−4 (90% C.L.) for E_nu > 1.8 MeV, covering the entire 8B spectrum. Best differential limits on anti-neutrino fluxes from unknown sources are also obtained between the detection energy threshold of 1.8 MeV and 17.8 MeV with more than 2 years of data.
Keywords: Anti-neutrinos; Solar neutrinos; Neutrino detector; Liquid scintillator