A direct measurement of the 0.862 MeV 7Be solar neutrino interaction rate performed with the Borexino detector at the Laboratori Nazionali del Gran Sasso yields 46.0±1.5stat+1.6−1.5syst counts/day/(100 tons). Our result is the first direct measurement of a sub-MeV solar neutrino rate with an accuracy better than 5%. The hypothesis of no oscillation for 7Be solar neutrinos is rejected at 4.9σ C.L. Using the latest Standard Solar Model (SSM) flux predictions, the result leads directly to a precise determination of the survival probability for solar νe's in vacuum, and permits us to probe with unprecedented sensitivity the transition between the matter-enhanced and vacuum-dominated neutrino oscillation regimes characteristic of the MSW-LMA solution to the solar neutrino problem.
Precision measurement of the Be7 solar neutrino interaction rate in Borexino / Bellini, G.; Suvorov, Y.; Et, Al.. - In: PHYSICAL REVIEW LETTERS. - ISSN 0031-9007. - 107:14(2011), p. 141302. [10.1103/PhysRevLett.107.141302]
Precision measurement of the Be7 solar neutrino interaction rate in Borexino
Suvorov, Y.;
2011
Abstract
A direct measurement of the 0.862 MeV 7Be solar neutrino interaction rate performed with the Borexino detector at the Laboratori Nazionali del Gran Sasso yields 46.0±1.5stat+1.6−1.5syst counts/day/(100 tons). Our result is the first direct measurement of a sub-MeV solar neutrino rate with an accuracy better than 5%. The hypothesis of no oscillation for 7Be solar neutrinos is rejected at 4.9σ C.L. Using the latest Standard Solar Model (SSM) flux predictions, the result leads directly to a precise determination of the survival probability for solar νe's in vacuum, and permits us to probe with unprecedented sensitivity the transition between the matter-enhanced and vacuum-dominated neutrino oscillation regimes characteristic of the MSW-LMA solution to the solar neutrino problem.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
