Article révisé par les pairs
Résumé : We report on the first direct observation of a neutrino induced charged-current interaction with two subsequent decays of short-lived particles close to the interaction vertex. This rare double-kink signature in the CHORUS emulsion target is interpreted as a Ds*+ production followed by the decay chain Ds*+ → Ds+ γ, Ds+ → τ+ vτ, τ+ → μ+ vμ vτ̄. The event is characterised by small Q2 and small four-momentum transfer squared t to the target nucleon, which indicates a diffractive production mechanism. A complete analysis of the event is presented. © 1998 Elsevier Science B.V. All rights reserved.