Diffractive $D_{s}^{*}$ production by neutrinos

The CHORUS experiment uses nuclear emulsion as primary neutrino target to detect decays of short-lived particles. We report on the observation of an event that shows two decays within 215 mu m. This rare double decay signature is interpreted as a neutrino induced D /sub s//sup */ production followed by the subsequent decay cascade D /sub s//sup *+/ to D/sub s//sup +/ gamma , D/sub s//sup +/ to tau /sup +/ nu /sub tau /, tau /sup +/ to mu /sup +/ nu /sub mu / nu /sub tau /. A small Q/sup 2/ and a small four-momentum transfer to the nucleon t indicate a diffractive production mechanism. (12 refs).