Lepton-flavor violation in the left-handed slepton production at future lepton colliders - art. no. 055008

The Super-Kamiokande atmospheric neutrino data suggest the existence of a l arge lepton-flavor violating (LFV) interaction in the higher energy scale. If the minimal supersymmetric standard model is extended to have right-hand ed neutrinos, the left-handed sleptons in the second and third generations are expected to have LFV masses in the minimal supergravity scenario. In th is article we study the LFV signals in the left-handed slepton production a t mu(+)mu(-) colliders and e(+)e(-) linear colliders (LC's), mu(+)mu(-) (e( +)e(-)) --> tau mu + 4 jets + E and mu(+)mu(-) (e(+)e(-)) --> tau mu l + 2 jets + E. The main background comes from decay of a tau lepton into a muon in the lepton-flavor conserving slepton pair production. They are significa ntly reduced by the energy and the impact parameter cuts for the muon. At m u(+)mu(-) colliders (LC's) it may be possible to reach the mixing angle sin 2 theta(<(nu)over tilde>)greater than or similar to 0.1 (0.5) and the mass difference Delta m(<(nu)over tilde>)greater than or similar to 0.1(0.4) Ge V for sneutrinos in the second and third generations at the statistical sig nificance of 3p. Such a small mass difference and a mixing angle may be ind uced radiatively even if the Yukawa coupling constant for the tau neutrino is of the order of 0.1. [S0556-2821(99)02315-2].