Oscillation Analysis and Results

Abstract

In this chapter, we describe the fit to the SK $\nu _{e}$ candidate data to measure the $\sin ^22\theta _{13}$ and $\delta _{CP}$. The analysis presented in this thesis (hereafter called “2013 analysis”) is the updated version of the analysis presented in 2012 (“2012 analysis”). The fit procedure is basically unchanged from 2012, but there are two additional things: $\bullet$ The value of $\sin ^22\theta _{23}$ and $\varDelta m_{32}^2$ were fixed in the 2012 analysis, but in the 2013 analysis we also do the fit with the uncertainties of these parameters taken into account. Because $P(\nu _{\mu }\rightarrow \nu _{e})$ depends on these parameters (Eq. 1.17), the uncertainties of these parameters are important in the precision measurement of $\sin ^22\theta _{13}$ and $\delta _{CP}$. $\bullet$ Additionally, we apply the constraint on $\sin ^22\theta _{13}$ from the reactor experiments to measure $\delta _{CP}$. The detail of the fit method is described in the following sections, together with the update in the 2013 analysis.