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 ${\theta }_{13}\ge 1^{\circ }$.

Comments: 6 pages, 8 figures. Presented at XXXVIII Rencontre De Moriond: Electroweak Interactions and Unified Theories Les Arcs, France, March 15--22, 2003