A High Intensity Linear e+e− Collider for a Tau-Charm Factory

A new high intensity e+e− linear collider serving as tau-charm factory is proposed. The design luminosity is 1035 cm−2 s−1 for center of mass energies of in the resonance region of Ψ vector mesons and in the region of maximum cross section for tau pair production. This new facility would provide about 1011 tau lepton pairs per year enabling precision studies of τ leptons and searches for rare τ decays with unprecedented sensitivity.Implications on the design of the linear accelerator are discussed together with requirements to achieve luminosities of 1035 cm−2 s−1 or more. The possibility to exploit energy recovery techniques in order to increase e+ beam currents and luminosity is discussed.