  Neutrino physics is nowadays receiving more and more attention as a possible
source of information for the long standing problem of new Physics beyond the
Standard Model. The recent measurements of the third mixing angle $\theta_{13}$
in the standard mixing oscillation scenario encourage to pursue the still
missing results on the leptonic CP violation and the absolute neutrino masses.
However, several puzzling and incomplete measurements are in place which
deserve an exhaustive evaluation and study. We will report about the present
situation of the muon disappearance measurements at small $L/E$ in the context
of the current CERN project to revitalize the neutrino field in Europe and the
search for sterile neutrinos. We will then illustrate the achievements that a
double muon spectrometer can attain in terms of discovery of new neutrino
states, performing a newly developed analysis.
