We show that a source-to-detector distance of 2540 km offers multiple
advantages for a low energy neutrino factory with a detector that can identify
muon charge. At this baseline, for any neutrino hierarchy, the wrong-sign muon
signal is almost independent of CP violation and θ13 in certain
energy ranges. This reduces the uncertainties due to these parameters and
allows the identification of the hierarchy in a clean way. In addition, part of
the muon spectrum is also sensitive to the CP violating phase and
θ13, so that the same setup can be used to probe these parameters as
well.Comment: 4 pages, 4 figures, Revtex4. Text modified. Version to appear in PR