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 ν¯e flux of 760 cm−2 s−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 Eν¯>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.
Study of solar and other unknown anti-neutrino fluxes with Borexino at LNGS
ORTICA, Fausto;ROMANI, Aldo;
2011
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 ν¯e flux of 760 cm−2 s−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 Eν¯>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.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
