Measurement of the $\hat{I}{½}_e$ and Total ${}^8$B Solar Neutrino Fluxes with the Sudbury Neutrino Observatory Phase-III Data Set

Abstract

This paper details the solar neutrino analysis of the 385.17-day Phase-III data set acquired by the Sudbury Neutrino Observatory (SNO). An array of ${}^3$He proportional counters was installed in the heavy-water target to measure precisely the rate of neutrino-deuteron neutral-current interactions. This technique to determine the total active ${}^8$B solar neutrino flux was largely independent of the methods employed in previous phases. The total flux of active neutrinos was measured to be $5.54_{-0.31}^{+0.33}(stat.{)}_{-0.34}^{+0.36}(syst.)\times 10^6$ cm${}^{-2}$ s${}^{-1}$, consistent with previous measurements and standard solar models. A global analysis of solar and reactor neutrino mixing parameters yielded the best-fit values of $\hat{I}”m^2=7.59_{-0.21}^{+0.19}\times 10^{-5}{eV}^2$ and $\hat{I}¸=34.4_{-1.2}^{+1.3}$ degrees.

104 pages, 26 figures, 20 tables, submitted to Phys. Rev. C