Puzzling out Neutrino Mixing Through Golden and Silver Measurements

Abstract

We update a recent work devoted to resolve the degeneracies that appear in the simultaneous extraction of $\theta_{13}$ and $\delta$ at future Neutrino Factories (NF, that exploit the \emph{golden} channels, i.e. $\nu_e\to\nu_\mu$ ($\bar{\nu}_e\to\bar{\nu}_\mu$)) and Superbeam experiments (SB, that measure the $\nu_\mu\to\nu_e$ ($\bar{\nu}_\mu\to\bar{\nu}_e$) transitions). We consider the neutrino fluxes obtained with a new optics design for the CERN-SPL SB and assume the solar parameters within the LMA-I and the LMA-II regions indicated by recent KamLAND data. The dangerous fake solution associated with the $\theta_{23}$-ambiguity remains after the combination of data from these two facilities: in this perspective, we analyze the impact of the NF-\emph{silver} channels, i.e. $\nu_e\to\nu_\tau$ ($\bar{\nu}_e\to\bar{\nu}_\tau$). The combination of data from these three experiments -NF(\emph{golden} and \emph{silver} channels) plus SPL SB- can discover leptonic CP violation for values of $\theta_{13}\ge 1^{\circ}$.