Observation of neutrino induced diffractive D-s*(+) production and subsequent decay D-s*(+)-> D-s(+)->tau(+)->mu(+)

摘要

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 D-s*(+) production followed by the decay chain D-s*(+) --> D-s(+) gamma, D-s(+) --> tau(+) v(tau),tau(+) --> mu(+) v(mu)v(tau). The event is characterised by small Q(2) 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. (C) 1998 Elsevier Science B.V. All rights reserved. [References: 15]