The Scientific Need for a Scalar/Higgs Factory
  The scalar sector of the electroweak theory can be probed by a mu^+mu^- collider S channel resonance machine. We give arguments for when such a machine may be needed and when this information could be obtained by the LHC detector. A very interesting case is the possibility that several scalar particles are in the same mass range for the supersymmetric Higgs bosons h, H, and A, which would definitely require such a machine. The Higgs factory could follow the construction of a neutrino factory. 
D. B. Cline