Long-baseline study of the leading neutrino oscillation at a neutrino factory

Within the framework of three-flavor neutrino oscillations, we consider the physics potential of ν_e→ν_μ appearance and ν_μ→ν_μ survival measurements at a neutrino factory for a leading oscillation scale δm²∼3.5×10^-3 eV². Event rates are evaluated versus baseline and stored muon energy, and optimal values discussed. Over a sizable region of oscillation parameter space, matter effects would enable the sign of δm² to be determined from a comparison of ν_e→ν_μ with ν̅ _e→ν̅ _μ event rates and energy distributions. It is important, therefore, that both positive and negative muons can be stored in the ring. Measurements of the ν_μ→ν_μ survival spectrum could determine the magnitude of δm² and the leading oscillation amplitude with a precision of O (1%-2%).