Physics Motivation: measure the coupling between Z and left handed tau, and the coupling between Z and right handed tau. This is going to be very useful to constrain some of the contact interactions, or to test models such as gauge-Higgs unification.
Search Channel: e+e- → tau tau, tau → 1-prong / 3-prong, Ecm = 500 GeV.
Detector Benchmark: highly boosted tau reconstruction; in 3-prong channel, interesting to test the limit of track separation; in 1-prong channel, interesting to test PFA performance.
final observables: gL, gR, (for Ztautau couplings); cross section for e+e- → tau_L tau_R / tau_R tau_L.
intermediate observables: efficiency of tau reconstruction, efficiency of tau decay mode identification, tau polarization