R-PARITY VIOLATION AND CP-VIOLATING AND CP-CONSERVING SPIN ASYMMETRIES IN L(-)-](NU)OVER-TILDE-]TAU(+)TAU(-) - PROBING S NEUTRINO MIXING ATL(+)L(-) COLLIDERS()L()

We consider the sneutrino resonance reaction l(+)l(-) --> (nu)over-til de --> tau(+)tau(-) in the minimal supersymmetric standard model (MSSM ) without R parity. We introduce CP-violating and CP-conserving tau-sp in asymmetries which are generated at tree level if there is (nu)over- tilde-((nu)over-tilde)over-bar mixing and are forbidden in the standar d model. At the CERN e(+)e(-) collider LEP2, these asymmetries may rea ch similar to 75% around resonance for sneutrino mass splitting of del ta m similar to gamma((nu)over-barmu) and similar to 10% for splitting as low as delta m similar to 0.1 gamma((nu))over-bar-mu. They may be easily detectable if the beam energy is within similar to 10 GeV aroun d the (nu)over-tilde(mu), mass and may therefore serve as powerful pro bes of sneutrino mixing. Future colliders are also discussed.