The time variation of the elastic scattering rate of solar neutrinos with electrons in Super-Kamiokande-I was fit to the variations expected from active two-neutrino oscillations. The best fit in the large mixing angle solution has a mixing angle of tan2θ=0.55 and a mass squared difference of Δm2 = 6.3×10-5 eV2 between the two neutrino mass eigenstates. The fitted day-night asymmetry of -1.8±1.6(stat)-12 +13(syst)% has improved statistical precision over previous measurements and agrees well with the expected asymmetry of -2.1%.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)