Neutrino oscillations at an entry-level neutrino factory and beyond

We consider the parameters of an entry-level neutrino factory designed to make the first observation of {nu}{sub e}{yields}{nu}{sub {mu}} oscillations, measure the corresponding amplitude sin{sup 2}2{theta}{sub 13}, and determine the sign of the atmospheric-scale {delta}m{sub 32}{sup 2} via matter effects. A 50 kt detector, a stored muon energy E{sub {mu}}{>=}20 GeV and 10{sup 19} muon decays would enable these goals to be met provided sin{sup 2}2{theta}{sub 13}>0.01. The determination of the sign of {delta}m{sub 32}{sup 2} also requires a baseline L{>=}2000 km. An upgraded neutrino factory with O(10{sup 20}) decays would enable the first observation of {nu}{sub e}{yields}{nu}{sub {tau}} oscillations. With O(10{sup 21}) decays the effects of a large CP phase could be measured in the case of the large angle matter oscillation solution to the solar neutrino anomaly. Our analysis includes a family of three-neutrino models that can account for the atmospheric and solar neutrino oscillation indications. (c) 2000 The American Physical Society.