$\tau$ appearance and CNGS

In December 1999, the CERN Council approved the CNGS project to explore neutrino oscillation physics in tau neutrino appearance. Super-KAMIOKANDE result indicate that the most probable solution in atmospheric neutrino disappearance is muon neutrino oscillation into a tau neutrino. CNGS is designed to detect nu /sub mu / to nu /sub tau / oscillations by a long baseline appearance experiment. CNGS a more is unique project than the other disappearance projects like K2K and NuMI. At least two experiments are in preparation in the CNGS project at LNGS. One is OPERA which was already approved in Feb. 2001 as CNGS1 using emulsion techniques which have proven their tau detection capability in Fermilab E872 DONUT. The other is ICARUS which was approved at LNGS using a liquid argon TPC. Both experiments will detect tau neutrino signal in theCNGS beam. (5 refs).