Abstract : The rate of neutrino-electron elastic scattering interactions from 862 keV Be7 solar neutrinos in Borexino is determined to be 46.0±1.5(stat)-1.6+1.5(syst)counts/(day*100ton). This corresponds to a νe-equivalent Be7 solar neutrino flux of (3.10±0.15)×109cm-2s-1 and, under the assumption of νe transition to other active neutrino flavours, yields an electron neutrino survival probability of 0.51±0.07 at 862 keV. The no flavor change hypothesis is ruled out at 5.0σ. A global solar neutrino analysis with free fluxes determines Φpp=6.06-0.06+0.02×1010cm-2s-1 and ΦCNO<1.3×109cm-2s-1 (95% C.L.). These results significantly improve the precision with which the Mikheyev-Smirnov-Wolfenstein large mixing angle neutrino oscillation model is experimentally tested at low energy.
http://hal.in2p3.fr/in2p3-00659724
Contributor : Daniel Vignaud <>
Submitted on : Friday, January 13, 2012 - 3:02:01 PM Last modification on : Monday, December 14, 2020 - 9:53:43 AM
G. Bellini, J. Benziger, D. Bick, S. Bonetti, G. Bonfini, et al.. Precision Measurement of the Be7 Solar Neutrino Interaction Rate in Borexino. Physical Review Letters, American Physical Society, 2011, 107, pp.141302. ⟨10.1103/PHYSREVLETT.107.141302⟩. ⟨in2p3-00659724⟩