Solar Neutrino Data Covering Solar Cycle 22

Abstract

Results from 1036 days of solar neutrino data accumulated in the upgraded Kamiokande detector (Kamiokande III) are presented. The ${}_{}{}^8{}_{}{}^{}\mathrm{B}$ solar neutrino flux observed in Kamiokande III is ${2.82}_{-0.24\mathrm{}}^{+0.25\mathrm{}}$ (stat) ± 0.27 (syst) × ${10}^6$ ${\mathrm{cm}}^{-2\mathrm{}}$ ${\mathrm{s}}^{-1\mathrm{}}$; the combined flux from Kamiokande II and III (2079 days in total) is 2.80 ± 0.19 (stat) ± 0.33 (syst) × ${10}^6$ ${\mathrm{cm}}^{-2\mathrm{}}$ ${\mathrm{s}}^{-1\mathrm{}}$, which is 49% to 64% of the standard solar models. These combined data from January 1987 to February 1995, covering an entire period of solar cycle 22, enabled us to study a correlation between the neutrino flux and the solar activity in detail: no strong correlation of the solar neutrino flux with the sunspot numbers was found within experimental errors. The result on a search for the daytime and nighttime flux difference is also reported.